Mycobacterium Paratuberculosis Detected by Nested PCR in Intestinal Granulomas Isolated by LCM in Cases of Crohn's Disease

Methods in Molecular Biology (Clifton, N.J.). 2002  |  Pubmed ID: 12325511

Fas Ligand Expressed in Colon Cancer is Not Associated with Increased Apoptosis of Tumor Cells in Vivo

International Journal of Cancer. Journal International Du Cancer. Nov, 2003  |  Pubmed ID: 12949796

Expression of Fas ligand (FasL/CD95L) may help to maintain colon cancers in a state of immune privilege by inducing apoptosis of antitumor immune effector cells. Colon tumor-derived cell lines appear to be relatively insensitive to apoptosis mediated by their own or exogenous FasL in vitro, despite expression of cell surface Fas. In our present study, we sought to investigate if FasL upregulated in human colon cancers leads to any increase in apoptosis of the tumor cells in vivo. FasL and Fas receptor (APO-1/CD95) expression by tumor cells were detected immunohistochemically. Apoptotic tumor cell death was detected by immunohistochemistry for caspase-cleaved cytokeratin-18. FasL expression did not correlate with the extent of apoptosis of tumor cells. There was no significant local difference in the frequency of apoptosis of tumor cells between tumor nests that expressed FasL (mean = 2.4%) relative to those that did not (mean = 2.6%) (p = 0.625, n = 10; Wilcoxon signed rank). FasL expressed by the tumor cells appeared to be functional, since FasL expression in tumor nests correlated with diminished infiltration of tumor-infiltrating lymphocytes (TILs). TILs were detected using immunohistochemistry for CD45. Expression of FasL by tumor nests was associated with a mean 4-fold fewer TILs relative to FasL-negative nests (range 2.4-33-fold, n = 10, p < 0.003). Together, our results indicate that colon tumors are insensitive to FasL-mediated apoptosis in vivo.

Effective Therapy for Advanced Gastrointestinal Stromal Tumors

Gastroenterology. Apr, 2003  |  Pubmed ID: 15534977

A Prospective Study of Common Bile Duct Calculi in Patients Undergoing Laparoscopic Cholecystectomy: Natural History of Choledocholithiasis Revisited

Annals of Surgery. Jan, 2004  |  Pubmed ID: 14685097

To define the incidence of problematic common bile duct calculi in patients undergoing laparoscopic cholecystectomy.

Prevalence of Bone Marrow Micrometastases in Esophagogastric Cancer Patients with and Without Neoadjuvant Chemoradiotherapy

The Journal of Surgical Research. Mar, 2004  |  Pubmed ID: 15013722

Bone marrow micrometastases are present in a high proportion of patients undergoing curative resection for esophagogastric cancer. The incorporation of preoperative systemic therapies into these patients' treatment is widely practiced. This study investigates the effect of neoadjuvant chemoradiotherapy (CRT) on the incidence of micrometastases and the viability of detected tumor cells.

Bacterial DNA Within Granulomas of Patients with Crohn's Disease--detection by Laser Capture Microdissection and PCR

The American Journal of Gastroenterology. Aug, 2004  |  Pubmed ID: 15307874

We previously reported the use of laser capture microdissection (LCM) and PCR to detect the presence of Mycobacterium paratuberculosis DNA in granulomas of patients with Crohn's disease. While this does not imply a cause-effect relationship, it may influence the disease process because bacterial DNA has immunomodulatory effects. The aim of this study was to determine whether DNA from nonmycobacterial commensals, such as Escherichia coli, is also increased in the granulomas of Crohn's disease.

Detection of Bone Marrow Micrometastases in the Rib Marrow of Head and Neck Cancer Patients: a Prospective Pilot Study

European Archives of Oto-rhino-laryngology : Official Journal of the European Federation of Oto-Rhino-Laryngological Societies (EUFOS) : Affiliated with the German Society for Oto-Rhino-Laryngology - Head and Neck Surgery. Feb, 2005  |  Pubmed ID: 15197562

Flow cytometry has been validated as an objective method of demonstrating and quantifying micrometastases. Micrometastases within bone marrow indicate a poor prognosis in patients with upper gastrointestinal, colorectal and breast epithelial tumours. We prospectively sought to assess the feasibility of testing rib marrow for bone marrow micrometastases in head and neck cancer and to report their frequency in a cohort of patients. Nine patients were enrolled in the study. Bone marrow was obtained before manipulation of the primary tumour. Micrometastatic cells were detected by staining contaminant cytokeratin-18 positive cells and using the twin techniques of immuncytochemistry and flow cytometry. Cellular marrow was retrieved in 100% of cases. Micrometastases were detected in one out of nine epithelial tumours on both flow cytometry and immunocytochemistry. The detection rate appeared to be independent of TN staging. We were unable to culture the cells. Preoperative detection of bone marrow micrometastases may reflect transient shedding of cells, metastatic potential or residual disease. This prospective study confirms the feasibility of using rib marrow in future studies investigating micrometastases in head and neck cancer.

Lactobacillus and Bifidobacterium in Irritable Bowel Syndrome: Symptom Responses and Relationship to Cytokine Profiles

Gastroenterology. Mar, 2005  |  Pubmed ID: 15765388

The aim of this study was to compare the response of symptoms and cytokine ratios in irritable bowel syndrome (IBS) with ingestion of probiotic preparations containing a lactobacillus or bifidobacterium strain.

Gastric Motor Dysfunction: is Eosinophilic Mural Gastritis a Causative Factor?

European Journal of Gastroenterology & Hepatology. Sep, 2005  |  Pubmed ID: 16093877

Delayed gastric emptying caused either by gastric motor dysfunction or by gastroparesis is a profoundly debilitating disorder. When unresponsive to medical therapy, patients may undergo radical surgery including near-total gastro-oesophageal, with varied symptomatic improvement. We describe two patients who presented with symptoms consistent with gastro-oesophageal reflux, unresponsive to medical management. After fundoplication both developed symptoms of profound gastric motor dysfunction and subsequently proceeded to near-total gastro-oesophageal with symptomatic improvement. Histological examination of both excised gastric specimens revealed eosinophilic mural gastritis. To our knowledge, these are the first cases to demonstrate the association of mural eosinophilia and symptomatic gastric motor dysfunction. We propose that patients with gastric motor dysfunction, refractory to medical management, progress to laparoscopy and mural biopsy before gastrectomy. This would allow histological analysis of the gastric wall, and in the event of a positive finding of mural eosinophilic gastritis would allow a trial of medical therapy that could include an eosinophilic stabilizer such as the leukotriene D4 receptor antagonist montelukast or intravenous corticosteroid therapy, which may alleviate the symptoms.

Correlation of Probiotic Lactobacillus Salivarius Growth Phase with Its Cell Wall-associated Proteome

FEMS Microbiology Letters. Nov, 2005  |  Pubmed ID: 16214296

Lactobacillus salivarius subsp. salivarius UCC118 is a probiotic bacterium that was originally isolated from human intestinal tissues and was subsequently shown in a pilot study to alleviate symptoms associated with mild-moderate Crohn's disease. Strain UCC118 can adhere to animal and human intestinal tissue, and to both healthy and inflamed ulcerative colitis mucosa, irrespective of location in the gut. In this study, an enzymatic technique has been combined with proteomic analysis to correlate bacterial growth phase with the presence of factors present in the cell wall of the bacterium. Using PAGE electrophoresis, it was determined that progression from lag to log to stationary growth phases in vitro correlated with increasing prominence of an 84kD protein associated with in vitro adherence ability. Isolated proteins from the 84kD band region were further separated by two-dimensional electrophoresis, resolving this band into 20 individual protein spots at differing isoelectric points. The protein moieties were excised, trypsin digested and subjected to tandem mass spectrometry. The observed proteins are analogous to those reported to be associated with the Listeria monocytogenes cell-wall proteome, and include DnaK, Ef-Ts and pyruvate kinase. These data suggest that at least some of the beneficial attributes of probiotic lactobacilli, and in particular this strain, may be due to nonpathogenic mimicry of pathogens and potentially be mediated through a form of attenuated virulence.

Symptoms in Cancer Patients and an Unusual Tumor: Case 2. Docetaxel-related Ischemic Colitis

Journal of Clinical Oncology : Official Journal of the American Society of Clinical Oncology. Dec, 2005  |  Pubmed ID: 16361642

Bcr-Abl Reduces Endoplasmic Reticulum Releasable Calcium Levels by a Bcl-2-independent Mechanism and Inhibits Calcium-dependent Apoptotic Signaling

Blood. May, 2006  |  Pubmed ID: 16469868

The Bcr-Abl oncoprotein plays a major role in the development and progression of chronic myeloid leukemia (CML). Several studies have suggested that the expression levels of Bcr-Abl are elevated at disease progression to blast crisis and that this plays a significant role in the achievement of drug resistance. We have established cell lines expressing low and high levels of Bcr-Abl to study the molecular mechanisms involved in disease progression and drug resistance. It is now known that the endoplasmic reticulum (ER) can play a major role in the regulation of apoptosis. We therefore investigated whether Bcr-Abl expression modulates ER homeostasis and interferes with ER-mediated apoptotic pathways to promote survival. Bcr-Abl-expressing cells exhibit a decreased amount of free releasable calcium in the ER as well as a weaker capacitative calcium entry response, relative to parental cells. This effect is independent of Bcl-2, which is a known modulator of ER calcium homeostasis. The reduction in ER releasable calcium results in inhibition of the ER/mitochondria-coupling process and mitochondrial calcium uptake. This study demonstrates a novel downstream consequence of Bcr-Abl signaling. The ability to negate calcium-dependent apoptotic signaling is likely to be a major prosurvival mechanism in Bcr-Abl-expressing cells.

Induction of Apoptosis in Renal Cell Carcinoma by Reactive Oxygen Species: Involvement of Extracellular Signal-regulated Kinase 1/2, P38delta/gamma, Cyclooxygenase-2 Down-regulation, and Translocation of Apoptosis-inducing Factor

Molecular Pharmacology. Jun, 2006  |  Pubmed ID: 16543392

Renal cell carcinoma (RCC) is the most common malignancy of the kidney. Unfortunately, RCCs are highly refractory to conventional chemotherapy, radiation therapy, and even immunotherapy. Thus, novel therapeutic targets need to be sought for the successful treatment of RCCs. We now report that 6-anilino-5,8-quinolinequinone (LY83583), an inhibitor of cyclic GMP production, induced growth arrest and apoptosis of the RCC cell line 786-0. It did not prove deleterious to normal renal epithelial cells, an important aspect of chemotherapy. To address the cellular mechanism(s), we used both genetic and pharmacological approaches. LY83583 induced a time- and dose-dependent increase in RCC apoptosis through dephosphorylation of mitogen-activated protein kinase kinase 1/2 and its downstream extracellular signal-regulated kinases (ERK) 1 and -2. In addition, we observed a decrease in Elk-1 phosphorylation and cyclooxygenase-2 (COX-2) down-regulation. We were surprised that we failed to observe an increase in either c-Jun NH(2)-terminal kinase or p38alpha and -beta mitogen-activated protein kinase activation. In contradiction, reintroduction of p38delta by stable transfection or overexpression of p38gamma dominant negative abrogated the apoptotic effect. Cell death was associated with a decrease and increase in Bcl-x(L) and Bax expression, respectively, as well as release of cytochrome c and translocation of apoptosis-inducing factor. These events were associated with an increase in reactive oxygen species formation. The antioxidant N-acetyl l-cysteine, however, opposed LY83583-mediated mitochondrial dysfunction, ERK1/2 inactivation, COX-2 down-regulation, and apoptosis. In conclusion, our results suggest that LY83583 may represent a novel therapeutic agent for the treatment of RCC, which remains highly refractory to antineoplastic agents. Our data provide a molecular basis for the anticancer activity of LY83583.

Multireplicon Genome Architecture of Lactobacillus Salivarius

Proceedings of the National Academy of Sciences of the United States of America. Apr, 2006  |  Pubmed ID: 16617113

Lactobacillus salivarius subsp. salivarius strain UCC118 is a bacteriocin-producing strain with probiotic characteristics. The 2.13-Mb genome was shown by sequencing to comprise a 1.83 Mb chromosome, a 242-kb megaplasmid (pMP118), and two smaller plasmids. Megaplasmids previously have not been characterized in lactic acid bacteria or intestinal lactobacilli. Annotation of the genome sequence indicated an intermediate level of auxotrophy compared with other sequenced lactobacilli. No single-copy essential genes were located on the megaplasmid. However, contingency amino acid metabolism genes and carbohydrate utilization genes, including two genes for completion of the pentose phosphate pathway, were megaplasmid encoded. The megaplasmid also harbored genes for the Abp118 bacteriocin, a bile salt hydrolase, a presumptive conjugation locus, and other genes potentially relevant for probiotic properties. Two subspecies of L. salivarius are recognized, salivarius and salicinius, and we detected megaplasmids in both subspecies by pulsed-field gel electrophoresis of sizes ranging from 100 kb to 380 kb. The discovery of megaplasmids of widely varying size in L. salivarius suggests a possible mechanism for genome expansion or contraction to adapt to different environments.

Hypertonic Saline Attenuates Colonic Tumor Cell Metastatic Potential by Activating Transmembrane Sodium Conductance

The Journal of Membrane Biology. May, 2006  |  Pubmed ID: 16988862

Hypertonic saline (HTS) suppresses tumor cell-endothelial interactions by reducing integrin expression. This translates into reduced adhesion, migration and metastatic potential. This study determined the relative contributions of hyperosmolarity and sodium-specific hypertonicity on the inhibitory effects of HTS, the intracellular pH and sodium responses to HTS and the role of cytoskeletal remodeling in these changes. Human colonic tumor cells (LS174T) were exposed to lipopolysaccharide under isotonic, hypertonic, sodium-free (N-methyl-D-glucamine), hyperosmolar (mannitol or urea), disrupted cytoskeletal (10 microg/ml cytochalasin D) conditions or in the presence of 5-(N-ethyl-N-isopropyl)amiloride (EIPA). Beta(1) integrin expression was measured flow-cytometrically. Intracellular sodium and pH were measured with confocal laser microscopic imaging. Statistical analysis was performed with analysis of variance, and P < 0.05 was considered significant. Data are represented as mean +/- SEM. Hypertonic exposure attenuated integrin expression (62.03 +/- 4.7% of control, P < 0.04). No discernible effect was observed with sodium-free or hyperosmolar solutions. HTS evoked a cellular alkalinization (by a mean 0.2 pH units) and an increase in cytosolic sodium concentration (by a mean 12.4 mM, P < 0.001) via upregulation of sodium-hydrogen exchange. Disassembly of actin microfilaments by cytochalasin D and antiporter inhibition with EIPA abrogated the effect of hypertonicity on integrin expression and intracellular sodium and pH (P < 0.05). HTS downregulates adhesion molecule expression via a hypertonic, sodium-specific, cytoskeletally mediated mechanism that involves activation of sodium-hydrogen exchange with associated changes in intracellular pH and sodium concentrations.

Oral Immune Tolerance Mediated by Suppressor T Cells May Be Responsible for the Poorer Prognosis of Foregut Cancers

Medical Hypotheses. 2006  |  Pubmed ID: 16288967

The poor prognosis of foregut cancers might, in part, be due to the immune tolerising effect of tumour antigens which are shed into the gastrointestinal tract and processed by the gut immune system. This would create a tumour specific tolerance without compromise of global immune functions. Experimental data shows that orally fed cancer tissue induces a non cross reactive attenuation of the cellular anti tumour host responses and confers a growth advantage specific to individual cancers. Although the cellular basis of such pro-tumourogenic responses has yet to be established, it is likely, based on studies of oral tolerance mechanisms, that recruitment of immune suppressive T cells (T(regs)) may be responsible. Abrogation of oral immune tolerance to the tumour by immune based therapy could represent a significant advance in the management of upper gastrointestinal cancers.

Successful Application of Targeted Electrochemotherapy Using Novel Flexible Electrodes and Low Dose Bleomycin to Solid Tumours

Cancer Letters. Feb, 2006  |  Pubmed ID: 15964138

Electroporation is the application of very brief electric pulses to cells or tissues to render the cell membranes transiently and reversibly permeable, facilitating cellular uptake of otherwise impermeant molecules. Flexible electrode arrays were developed which may be used with endoscopic and laparoscopic devices for delivery of therapeutic electroporation. Their efficacy in enhancing the delivery of bleomycin, an impermeant drug, was assessed in vitro and in vivo in both human and murine cancer cell lines, and growing tumours (xenografts). These flexible electrodes consistently and predictably deliver the permeabilising electric pulses requisite for in vivo electroporation, and would be suitable for electrochemotherapy of endoluminal tumours when incorporated into an endoscopic delivery system.

Dietary Synbiotics Reduce Cancer Risk Factors in Polypectomized and Colon Cancer Patients

The American Journal of Clinical Nutrition. Feb, 2007  |  Pubmed ID: 17284748

Animal studies suggest that prebiotics and probiotics exert protective effects against tumor development in the colon, but human data supporting this suggestion are weak.

Improved Luciferase Tagging System for Listeria Monocytogenes Allows Real-time Monitoring in Vivo and in Vitro

Applied and Environmental Microbiology. May, 2007  |  Pubmed ID: 17351089

An improved system for luciferase tagging Listeria monocytogenes was developed by constructing a highly active, constitutive promoter. This construct gave 100-fold-higher activity in broth than any native promoter tested and allowed for imaging of lux-tagged L. monocytogenes in food products, during murine infections, and in tumor targeting studies.

Electrochemotherapy: Aspects of Preclinical Development and Early Clinical Experience

Annals of Surgery. Mar, 2007  |  Pubmed ID: 17435555

To develop an optimized, reproducible system of electrochemotherapy, and to investigate its clinical application in patients with cutaneous or subcutaneous recurrences of inoperable or progressive disease recalcitrant to current anticancer treatments.

Modulation of P21-activated Kinase 1 Alters the Behavior of Renal Cell Carcinoma

International Journal of Cancer. Journal International Du Cancer. Nov, 2007  |  Pubmed ID: 17621631

The p21-activated kinase 1 (Pak1) is a serine/threonine kinase whose activity is regulated by both Rho GTPases and AGC kinase family members. It plays a role in cytoskeletal remodeling and cell motility as well as cell proliferation, angiogenesis, tumorigenesis and metastasis. An involvement of Pak1 in renal cell carcinoma (RCC), which remains highly refractory to chemotherapy and radiotherapy, remains to be investigated. Pak1 expression, phosphorylation and kinase activity were examined in RCC cell lines and human tissue from normal and renal carcinoma. We report increased Pak1 expression and constitutive activity in the membrane and nucleus but not the cytoplasm of resected human RCC. To study a role for Pak1 in RCC, we developed 786-0 clones that expressed either a kinase-active Pak1L83,L86 2 different Pak1 dominant negative mutants, Pak1R299 and Pak1L83,L86,R299 or Pak1 siRNA. The expression of Pak1L83,L86 increased 786-0 proliferation, motility and anchorage independent growth, while the dominant negative mutants and Pak1 siRNA abrogated these effects. In addition, Pak1L83,L86 conferred resistance to 5-fluorouracil with a 40%+/-10% increase in cell viability. Conversely, Pak1L83,L86,R299, Pak1R299 and Pak1 siRNA conferred sensitivity with a 65.2%+/-5.5%, 69.2%+/-3.3% and 73.0%+/-8.4% loss in viability, respectively. Finally, Pak1 plays a role in renal tumor growth in vivo. Only 33% of mice developed tumors in the Pak1L83,L86,R299 group and no tumors developed from Pak1R299 cell challenge. Together these findings point to Pak1 as an exciting target for therapy of renal cancer, which remains highly refractory to existing treatments.

Number and Size of Lymph Nodes Recovered from Dukes B Rectal Cancers: Correlation with Prognosis and Histologic Antitumor Immune Response

Diseases of the Colon and Rectum. Oct, 2007  |  Pubmed ID: 17828403

In rectal cancer variation in lymph node recovery influences the detection of nodal metastases and prognosis among Dukes B (Stage II) cases. However, the possible prognostic importance of node size and inherent patient/tumor characteristics in determining node recovery has not been studied.

Effective Tumor Treatment Using Optimized Ultrasound-mediated Delivery of Bleomycin

Ultrasound in Medicine & Biology. Mar, 2008  |  Pubmed ID: 17988788

Bleomycin is a nonpermeant, hydrophilic macromolecule with a high intrinsic anticancer cytotoxicity. However, the cytotoxic potential of the drug is restricted by its low membrane permeability. Application of low-intensity ultrasound to growing tumors enhances intracellular delivery of bleomycin after IP or intratumoral administration, thereby potentiating its cytotoxicity. Optimization of ultrasound parameters for in-vivo bleomycin delivery was undertaken, and an effective antitumor effect was demonstrated in solid tumors of both murine and human cell lines. Cell death after treatment was shown to occur by an apoptotic mechanism. The results achieved in these experiments were equivalent to those achieved using electroporation to mediate delivery of bleomycin-electrochemotherapy. We found that, although temperature rises of up to 5 degrees C occur using the optimized ultrasound conditions, this effect is not responsible for the potentiated drug cytotoxicity. This technique could be used with focused ultrasound or with endoscopic ultrasound probes to develop a localized and effective anticancer treatment with little or no systemic toxicity. (E-mail: Geraldc@ccrc.ie).

Culture-independent Analysis of the Gut Microbiota in Colorectal Cancer and Polyposis

Environmental Microbiology. Mar, 2008  |  Pubmed ID: 18237311

A role for the intestinal microbiota is routinely cited as a potential aetiological factor in colorectal cancer initiation and progression. As the majority of bacteria in the gut are refractory to culture we investigated this ecosystem in subjects with colorectal cancer and with adenomatous polyposis who are at high risk of developing colorectal cancer, using culture-independent methods. Twenty colorectal cancer and 20 polypectomized volunteers were chosen for this analysis. An exploration of the diversity and temporal stability of the dominant bacteria and several bacterial subgroups was undertaken using 16S rRNA gene denaturing gradient gel electrophoresis and ribosomal intergenic spacer analysis (RISA). Metabonomic analysis of the distal gut microbiota's environment was also undertaken. A significantly reduced temporal stability and increased diversity for the microbiota of subjects with colorectal cancer and polyposis was evident. A significantly increased diversity of the Clostridium leptum and C. coccoides subgroups was also noted for both disease groups. A clear division in the metabonome was observed for the colorectal cancer and polypectomized subjects compared with control volunteers. The intestinal microbiota and their metabolites are significantly altered in both colorectal cancer and polypectomized subjects compared with controls.

Electrochemotherapy: an Emerging Cancer Treatment

International Journal of Hyperthermia : the Official Journal of European Society for Hyperthermic Oncology, North American Hyperthermia Group. May, 2008  |  Pubmed ID: 18393004

The aim of this review article is to provide a concise overview of the pre-clinical development of electrochemotherapy (ECT), its present utility in clinical practice and to examine its potential application to therapeutic modalities in the future.

Viral Vectors in Cancer Immunotherapy: Which Vector for Which Strategy?

Current Gene Therapy. Apr, 2008  |  Pubmed ID: 18393828

Gene therapy involves the transfer of genetic information to a target cell to facilitate the production of therapeutic proteins and is now a realistic prospect as a cancer treatment. Gene transfer may be achieved through the use of both viral and non-viral delivery methods and the role of this method in the gene therapy of cancer has been demonstrated. Viruses represent an attractive vehicle for cancer gene therapy due to their high efficiency of gene delivery. Many viruses can mediate long term gene expression, while some are also capable of infecting both dividing and non-dividing cells. Given the broadly differing capabilities of various viral vectors, it is imperative that the functionality of the virus meets the requirements of the specific treatment. A number of immunogene therapy strategies have been undertaken, utilising a range of viral vectors, and studies carried out in animal models and patients have demonstrated the therapeutic potential of viral vectors to carry genes to cancer cells and induce anti-tumour immune responses. This review critically discusses the advances in the viral vector mediated delivery of immunostimulatory molecules directly to tumour cells, the use of viral vectors to modify tumour cells, the creation of whole cell vaccines and the direct delivery of tumour antigens in animal models and clinical trials, specifically in the context of the suitability of vector types for specific strategies.

Role of the VHL (von Hippel-Lindau) Gene in Renal Cancer: a Multifunctional Tumour Suppressor

Biochemical Society Transactions. Jun, 2008  |  Pubmed ID: 18481984

The VHL (von Hippel-Lindau) tumour-suppressor gene is inactivated in VHL disease and in sporadic cases of CCRCC [clear-cell RCC (renal cell carcinoma)]. pVHL (VHL protein) functions as part of an E3 ubiquitin ligase complex that targets proteins for proteasomal degradation. The best-characterized substrate is HIF-alpha (hypoxia-inducible factor-alpha). Loss of pVHL and subsequent up-regulation of HIF target genes has been attributed to the highly vascular nature of these neoplasms. However, pVHL does not just function as the executioner of HIF-alpha. Additional functions of pVHL that may be important in preventing CCRCC tumorigenesis have been identified, including primary cilium maintenance, assembly of the extracellular matrix and roles in the stabilization of p53 and Jade-1 (gene for apoptosis and differentiation in epithelia). Current evidence indicates that pVHL probably requires additional co-operating signalling pathways for CCRCC initiation and tumorigenesis.

Anti-metastatic Effects of Viral and Non-viral Mediated Nk4 Delivery to Tumours

Genetic Vaccines and Therapy. 2009  |  Pubmed ID: 19272140

The most common cause of death of cancer sufferers is through the occurrence of metastases. The metastatic behaviour of tumour cells is regulated by extracellular growth factors such as hepatocyte growth factor (HGF), a ligand for the c-Met receptor tyrosine kinase, and aberrant expression/activation of the c-Met receptor is closely associated with metastatic progression. Nk4 (also known as Interleukin (IL)32b) is a competitive antagonist of the HGF c-Met system and inhibits c-Met signalling and tumour metastasis. Nk4 has an additional anti-angiogenic activity independent of its HGF-antagonist function. Angiogenesis-inhibitory as well as cancer-specific apoptosis inducing effects make the Nk4 sequence an attractive candidate for gene therapy of cancer. This study investigates the inhibition of tumour metastasis by gene therapy mediated production of Nk4 by the primary tumour. Optimal delivery of anti-cancer genes is vital in order to achieve the highest therapeutic responses. Non-viral plasmid delivery methods have the advantage of safety and ease of production, providing immediate transgene expression, albeit short-lived in most tumours. Sustained presence of anti-angiogenic molecules is preferable with anti-angiogenic therapies, and the long-term expression mediated by Adeno-associated Virus (AAV) might represent a more appropriate delivery in this respect. However, the incubation time required by AAV vectors to reach appropriate gene expression levels hampers efficacy in many fast-growing murine tumour models. Here, we describe murine trials assessing the effects of Nk4 on the spontaneously metastatic Lewis Lung Carcinoma (LLC) model when delivered to primary tumour via plasmid lipofection or AAV2 vector. Intratumoural AAV-Nk4 administration produced the highest therapeutic response with significant reduction in both primary tumour growth and incidence of lung metastases. Plasmid-mediated therapy also significantly reduced metastatic growth, but with moderate reduction in primary subcutaneous tumour growth. Overall, this study demonstrates the potential for Nk4 gene therapy of metastatic tumours, when delivered by AAV or non-viral methods.

Prostate Stem Cell Antigen DNA Vaccination Breaks Tolerance to Self-antigen and Inhibits Prostate Cancer Growth

Molecular Therapy : the Journal of the American Society of Gene Therapy. Jun, 2009  |  Pubmed ID: 19337234

Prostate stem cell antigen (PSCA) is a cell surface antigen expressed in normal human prostate and over expressed in prostate cancer. Elevated levels of PSCA protein in prostate cancer correlate with increased tumor stage/grade, with androgen independence and have higher expression in bone metastases. In this study, the PSCA gene was isolated from the transgenic adenocarcinoma mouse prostate cell line (TRAMPC1), and a vaccine plasmid construct was generated. This plasmid PSCA (pmPSCA) was delivered by intramuscular electroporation (EP) and induced effective antitumor immune responses against subcutaneous TRAMPC1 tumors in male C57 BL/6 mice. The pmPSCA vaccination inhibited tumor growth, resulting in cure or prolongation in survival. Similarly, the vaccine inhibited metastases in PSCA expressing B16 F10 tumors. There was activation of Th-1 type immunity against PSCA, indicating the breaking of tolerance to a self-antigen. This immunity was tumor specific and was transferable by adoptive transfer of splenocytes. The mice remained healthy and there was no evidence of collateral autoimmune responses in normal tissues. EP-assisted delivery of the pmPSCA evoked strong specific responses and could, in neoadjuvant or adjuvant settings, provide a safe and effective immune control of prostate cancer, given that there is significant homology between human and mouse PSCA.

Electrochemotherapy As an Adjunct or Alternative to Other Treatments for Unresectable or In-transit Melanoma

Expert Review of Anticancer Therapy. Nov, 2009  |  Pubmed ID: 19895245

Treatment of recurrent or in-transit unresectable melanoma continues to be a major therapeutic challenge. Electrochemotherapy (ECT) is a therapeutic option for those patients whose lesions are not suitable for surgical resection and who have exhausted all other treatment modalities. ECT combines electroporation of tumor cells with the administration either of intravenous or intratumoral antineoplastic drugs, such as bleomycin or cisplatin. The cell membranes are thus rendered permeant to these impermeant hydrophilic drugs with a several hundred-fold increase in intracellular delivery and cytotoxicity. ECT is an effective treatment in the palliative management of unresectable recurrent disease with overall objective response rates of approximately 80-90%. ECT technology continues to evolve allowing application to deeper lesions. By combining ECT with tumor-specific immunostimulating approaches, such as perilesional IL-2, CpG oligonucleotides or prior immunogene therapy, there is a promise of both local and systemic control of this disease.

Electroporation of RNA Stimulates Immunity to an Encoded Reporter Gene in Mice

Molecular Medicine Reports. Sep-Oct, 2009  |  Pubmed ID: 21475897

Electroporation is the application of high-voltage short-duration pulses to transiently permeabilize cells, permitting the cellular uptake of macromolecules, including nucleic acid. Although much attention has been focused on DNA vaccines, antigen-encoding RNA molecules may also stimulate immunity. Several methods are being examined in an effort to enhance the efficacy of nucleic acid delivery. One such method is the application of electroporation. The present study was designed to develop electroporation for use as a method of RNA delivery in conjunction with the Semliki Forest virus (SFV) RNA vector system for stimulation of immunity. Expression of SFV-based β-galactosidase and luciferase vectors was observed in the muscle after electroporation. Although some tissue damage was induced following intramuscular injection and electroporation with SFV vector RNA encoding LacZ at optimum pulse conditions, immunity to LacZ was efficiently induced. Following two immunizations, there was a higher IgG2a antibody response with the viral vector delivery and a higher IgG1 response in electroporated rSFV-LacZ RNA immunized mice.

AAV2-mediated in Vivo Immune Gene Therapy of Solid Tumours

Genetic Vaccines and Therapy. 2010  |  Pubmed ID: 21172020

Many strategies have been adopted to unleash the potential of gene therapy for cancer, involving a wide range of therapeutic genes delivered by various methods. Immune therapy has become one of the major strategies adopted for cancer gene therapy and seeks to stimulate the immune system to target tumour antigens. In this study, the feasibility of AAV2 mediated immunotherapy of growing tumours was examined, in isolation and combined with anti-angiogenic therapy.

International Society for Cell and Gene Therapy of Cancer 2009 Annual Meeting Held in Cork, Ireland

Human Gene Therapy. Jan, 2010  |  Pubmed ID: 20017714

The International Society for Cell and Gene Therapy (ISCGT) of Cancer annual meeting was held from September 2 through September 4, 2009, in Cork, Ireland ( www.iscgt2009.com ). The conference was held in conjunction with the Irish Society for Gene and Cell Therapy third annual meeting, and brought together scientists and clinicians from around the world in a country developing its knowledge economy. Next year's ISCGT meeting will be held in Doha, the capital of Qatar ( www.iscgt.net ), from September 27 through September 29, 2010.

A Novel Listeria Monocytogenes-based DNA Delivery System for Cancer Gene Therapy

Human Gene Therapy. Apr, 2010  |  Pubmed ID: 20105075

Bacteria-mediated transfer of plasmid DNA to mammalian cells (bactofection) has been shown to have significant potential as an approach to express heterologous proteins in various cell types. This is achieved through entry of the entire bacterium into cells, followed by release of plasmid DNA. In a murine model, we show that Listeria monocytogenes can invade and spread in tumors, and establish the use of Listeria to deliver genes to tumors in vivo. A novel approach to vector lysis and release of plasmid DNA through antibiotic administration was developed. Ampicillin administration facilitated both plasmid transfer and safety control of vector. To further improve on the gene delivery system, we selected a Listeria monocytogenes derivative that is more sensitive to ampicillin, and less pathogenic than the wild-type strain. Incorporation of a eukaryotic-transcribed lysin cassette in the plasmid further increased bacterial lysis. Successful gene delivery of firefly luciferase to growing tumors in murine models and to patient breast tumor samples ex vivo was achieved. The model described encompasses a three-phase treatment regimen, involving (1) intratumoral administration of vector followed by a period of vector spread, (2) systemic ampicillin administration to induce vector lysis and plasmid transfer, and (3) systemic administration of combined moxifloxacin and ampicillin to eliminate systemic vector. For the first time, our results reveal the potential of Listeria monocytogenes for in vivo gene delivery.

Sonoporation Mediated Immunogene Therapy of Solid Tumors

Ultrasound in Medicine & Biology. Mar, 2010  |  Pubmed ID: 20133039

Development of gene-based therapies for the treatment of inherited and acquired diseases, including cancer, has seen renewed interest in the use of nonviral vectors coupled to physical delivery modalities. Low-frequency ultrasound (US), with a well-established record in a clinical setting, has the potential to deliver DNA efficiently, accurately and safely. Optimal in vivo parameters for US-mediated delivery of naked plasmid DNA were established using the firefly luciferase reporter gene construct. Optimized parameters were used to administer a therapeutic gene construct, coding for granulocyte-macrophage colony-stimulating factor (GM-CSF) and B7-1 costimulatory molecule, to growing murine fibrosarcoma tumors. Tumor progression and animal survival was monitored throughout the study and the efficacy of the US-mediated gene therapy determined and compared with an electroporation-based approach. Optimal parameters for US-mediated delivery of plasmid DNA to tumors were deduced to be 1.0 W/cm(2) at 20% duty cycle for 5 min (60 J/cm(2)). In vivo US-mediated gene therapy resulted in a 55% cure rate in tumor-bearing animals. The immunological response invoked was cell mediated, conferring resistance against re-challenge and resistance to tumor challenge after transfer of splenocytes to naïve animals. US treatment was noninjurious to treated tissue, whereas therapeutic efficacy was comparable to an electroporation-based approach. US-mediated delivery of an immune-gene construct to growing tumors was therapeutically effective. Sonoporation has the potential to be a major factor in the development of nonviral gene delivery approaches.

Tumour Targeting with Systemically Administered Bacteria

Current Gene Therapy. Feb, 2010  |  Pubmed ID: 20156191

Challenges for oncology practitioners and researchers include specific treatment and detection of tumours. The ideal anti-cancer therapy would selectively eradicate tumour cells, whilst minimising side effects to normal tissue. Bacteria have emerged as biological gene vectors with natural tumour specificity, capable of homing to tumours and replicating locally to high levels when systemically administered. This property enables targeting of both the primary tumour and secondary metastases. In the case of invasive pathogenic species, this targeting strategy can be used to deliver genes intracellularly for tumour cell expression, while non-invasive species transformed with plasmids suitable for bacterial expression of heterologous genes can secrete therapeutic proteins locally within the tumour environment (cell therapy approach). Many bacterial genera have been demonstrated to localise to and replicate to high levels within tumour tissue when intravenously (IV) administered in rodent models and reporter gene tagging of bacteria has permitted real-time visualisation of this phenomenon. Live imaging of tumour colonising bacteria also presents diagnostic potential for this approach. The nature of tumour selective bacterial colonisation appears to be tumour origin- and bacterial species- independent. While originally a correlation was drawn between anaerobic bacterial colonisation and the hypoxic nature of solid tumours, it is recently becoming apparent that other elements of the unique microenvironment within solid tumours, including aberrant neovasculature and local immune suppression, may be responsible. Here, we consider the pre-clinical data supporting the use of bacteria as a tumour-targeting tool, recent advances in the area, and future work required to develop it into a beneficial clinical tool.

Optimised Electroporation Mediated DNA Vaccination for Treatment of Prostate Cancer

Genetic Vaccines and Therapy. 2010  |  Pubmed ID: 20181099

Immunological therapies enhance the ability of the immune system to recognise and destroy cancer cells via selective killing mechanisms. DNA vaccines have potential to activate the immune system against specific antigens, with accompanying potent immunological adjuvant effects from unmethylated CpG motifs as on prokaryotic DNA. We investigated an electroporation driven plasmid DNA vaccination strategy in animal models for treatment of prostate cancer.

Orally Administered Bifidobacteria As Vehicles for Delivery of Agents to Systemic Tumors

Molecular Therapy : the Journal of the American Society of Gene Therapy. Jul, 2010  |  Pubmed ID: 20389288

Certain bacteria have emerged as biological gene vectors with natural tumor specificity, capable of specifically delivering genes or gene products to the tumor environment when intravenously (i.v.) administered to rodent models. We show for the first time that oral administration of bacteria to mice resulted in their translocation from the gastrointestinal tract (GIT) with subsequent homing to and replication specifically in tumors. The commensal, nonpathogenic Bifidobacterium breve UCC2003 harboring a plasmid expressing lux fed to mice bearing subcutaneous (s.c.) tumors were readily detected specifically in tumors, by live whole-body imaging, at levels similar to i.v. administration. Reporter gene expression was visible for >2 weeks in tumors. Mice remained healthy throughout experiments. Cytokine analyses indicated a significant upregulation of interferon-gamma (IFN-gamma) in the GIT of bifidobacteria-fed mice, which is associated with increases in epithelial permeability. However, B. breve feeding did not increase systemic levels of other commensal bacteria. The presence of tumor was not necessary for translocation to systemic organs to occur. These findings indicate potential for safe and efficient gene-based treatment and/or detection of tumors via ingestion of nonpathogenic bacteria expressing therapeutic or reporter genes.

Gene Therapy for Prostate Cancer

Postgraduate Medicine. May, 2010  |  Pubmed ID: 20463426

Cancer remains a leading cause of morbidity and mortality. Despite advances in understanding, detection, and treatment, it accounts for almost one-fourth of all deaths per year in Western countries. Prostate cancer is currently the most commonly diagnosed noncutaneous cancer in men in Europe and the United States, accounting for 15% of all cancers in men. As life expectancy of individuals increases, it is expected that there will also be an increase in the incidence and mortality of prostate cancer. Prostate cancer may be inoperable at initial presentation, unresponsive to chemotherapy and radiotherapy, or recur following appropriate treatment. At the time of presentation, patients may already have metastases in their tissues. Preventing tumor recurrence requires systemic therapy; however, current modalities are limited by toxicity or lack of efficacy. For patients with such metastatic cancers, the development of alternative therapies is essential. Gene therapy is a realistic prospect for the treatment of prostate and other cancers, and involves the delivery of genetic information to the patient to facilitate the production of therapeutic proteins. Therapeutics can act directly (eg, by inducing tumor cells to produce cytotoxic agents) or indirectly by upregulating the immune system to efficiently target tumor cells or by destroying the tumor's vasculature. However, technological difficulties must be addressed before an efficient and safe gene medicine is achieved (primarily by developing a means of delivering genes to the target cells or tissue safely and efficiently). A wealth of research has been carried out over the past 20 years, involving various strategies for the treatment of prostate cancer at preclinical and clinical trial levels. The therapeutic efficacy observed with many of these approaches in patients indicates that these treatment modalities will serve as an important component of urological malignancy treatment in the clinic, either in isolation or in combination with current approaches.

VHL Genetic Alteration in CCRCC Does Not Determine De-regulation of HIF, CAIX, HnRNP A2/B1 and Osteopontin

Analytical Cellular Pathology (Amsterdam). 2010  |  Pubmed ID: 20978319

von Hippel-Lindau (VHL) tumour suppressor gene inactivation is associated with clear cell renal cell carcinoma (CCRCC) development. The VHL protein (pVHL) has been proposed to regulate the expression of several proteins including Hypoxia Inducible Factor-α (HIF-α), carbonic anhydrase (CA)IX, heterogeneous nuclear ribonucleoprotein (hnRNP) A2/B1 and osteopontin. pVHL has been characterized in vitro, however, clinical studies are limited. We evaluated the impact of VHL genetic alterations on the expression of several pVHL protein targets in paired normal and tumor tissue.

Advancing Surgical Research in a Sea of Complexity

Annals of Surgery. Nov, 2010  |  Pubmed ID: 21037425

Bacteria As Vectors for Gene Therapy of Cancer

Bioengineered Bugs. Nov-Dec, 2010  |  Pubmed ID: 21468205

Anti-cancer therapy faces major challenges, particularly in terms of specificity of treatment. The ideal therapy would eradicate tumor cells selectively with minimum side effects on normal tissue. Gene or cell therapies have emerged as realistic prospects for the treatment of cancer, and involve the delivery of genetic information to a tumor to facilitate the production of therapeutic proteins. However, there is still much to be done before an efficient and safe gene medicine is achieved, primarily developing the means of targeting genes to tumors safely and efficiently. An emerging family of vectors involves bacteria of various genera. It has been shown that bacteria are naturally capable of homing to tumors when systemically administered resulting in high levels of replication locally. Furthermore, invasive species can deliver heterologous genes intra-cellularly for tumor cell expression. Here, we review the use of bacteria as vehicles for gene therapy of cancer, detailing the mechanisms of action and successes at preclinical and clinical levels.

Autophagy Induction by Bcr-Abl-expressing Cells Facilitates Their Recovery from a Targeted or Nontargeted Treatment

American Journal of Hematology. Jan, 2011  |  Pubmed ID: 21132731

Although Imatinib has transformed the treatment of chronic myeloid leukemia (CML), it is not curative due to the persistence of resistant cells that can regenerate the disease. We have examined how Bcr-Abl-expressing cells respond to two mechanistically different therapeutic agents, etoposide and Imatinib. We also examined Bcr-Abl expression at low and high levels as elevated expression has been associated with treatment failure. Cells expressing low levels of Bcr-Abl undergo apoptosis in response to the DNA-targeting agent (etoposide), whereas high-Bcr-Abl-expressing cells primarily induce autophagy. Autophagic populations engage a delayed nonapoptotic death; however, sufficient cells evade this and repopulate following the withdrawal of the drug. Non-Bcr-Abl-expressing 32D or Ba/F3 cells induce both apoptosis and autophagy in response to etoposide and can recover. Imatinib treatment induces both apoptosis and autophagy in all Bcr-Abl-expressing cells and populations rapidly recover. Inhibition of autophagy with ATG7 and Beclin1 siRNA significantly reduced the recovery of Imatinib-treated K562 cells, indicating the importance of autophagy for the recovery of treated cells. Combination regimes incorporating agents that disrupt Imatinib-induced autophagy would remain primarily targeted and may improve response to the treatment in CML.

Induction of Autophagy by Drug-resistant Esophageal Cancer Cells Promotes Their Survival and Recovery Following Treatment with Chemotherapeutics

Autophagy. May, 2011  |  Pubmed ID: 21325880

We investigated the cell-death mechanisms induced in esophageal cancer cells in response to the chemotherapeutic drugs, 5-fluorouracil (5-FU) and cisplatin. Chemosensitive cell lines exhibited apoptosis whereas chemoresistant populations exhibited autophagy and a morphology resembling type II programmed cell death (PCD). Cell populations that respond with autophagy are more resistant and will recover following withdrawal of the chemotherapeutic agents. Specific inhibition of early autophagy induction with siRNA targeted to Beclin 1 and ATG7 significantly enhanced the effect of 5-FU and reduced the recovery of drug-treated cells. Pharmacological inhibitors of autophagy were evaluated for their ability to improve chemotherapeutic effect. The PtdIns 3-kinase inhibitor 3-methyladenine did not enhance the cytotoxicity of 5-FU. Disruption of lysosomal activity with bafilomycin A 1 or chloroquine caused extensive vesicular accumulation but did not improve chemotherapeutic effect. These observations suggest that an autophagic response to chemotherapy is a survival mechanism that promotes chemoresistance and recovery and that selective inhibition of autophagy regulators has the potential to improve chemotherapeutic regimes. Currently available indirect inhibitors of autophagy are, however, ineffective at modulating chemosensitivity in these esophageal cancer cell lines.

Can Non-viral Technologies Knockdown the Barriers to SiRNA Delivery and Achieve the Next Generation of Cancer Therapeutics?

Biotechnology Advances. Jul-Aug, 2011  |  Pubmed ID: 21435387

Cancer is one of the most wide-spread diseases of modern times, with an estimated increase in the number of patients diagnosed worldwide, from 11.3 million in 2007 to 15.5 million in 2030 (www.who.int). In many cases, due to the delay in diagnosis and high increase of relapse, survival rates are low. Current therapies, including surgery, radiation and chemotherapy, have made significant progress, but they have many limitations and are far from ideal. Although immunotherapy has recently offered great promise as a new approach in cancer treatment, it is still very much in its infancy and more information on this approach is required before it can be widely applied. For these reasons effective, safe and patient-acceptable cancer therapy is still largely an unmet clinical need. Recent knowledge of the genetic basis of the disease opens up the potential for cancer gene therapeutics based on siRNA. However, the future of such gene-based therapeutics is dependent on achieving successful delivery. Extensive research is ongoing regarding the design and assessment of non-viral delivery technologies for siRNA to treat a wide range of cancers. Preliminary results on the first human Phase I trial for solid tumours, using a targeted non-viral vector, illustrate the enormous therapeutic benefits once the issue of delivery is resolved. In this review the genes regulating cancer will be discussed and potential therapeutic targets will be identified. The physiological and biochemical changes caused by tumours, and the potential to exploit this knowledge to produce bio-responsive 'smart' delivery systems, will be evaluated. This review will also provide a critical and comprehensive overview of the different non-viral formulation strategies under investigation for siRNA delivery, with particular emphasis on those designed to exploit the physiological environment of the disease site. In addition, a section of the review will be dedicated to pre-clinical animal models used to evaluate the stability, safety and efficacy of the delivery systems.

Preclinical Evaluation of Gene Delivery Methods for the Treatment of Loco-regional Disease in Breast Cancer

Experimental Biology and Medicine (Maywood, N.J.). Apr, 2011  |  Pubmed ID: 21444371

Preclinical results with various gene therapy strategies indicate significant potential for new cancer treatments. However, many therapeutics fail at clinical trial, often due to differences in tissue physiology between animal models and humans, and tumor phenotype variation. Clinical data relevant to treatment strategies may be generated prior to clinical trial through experimentation using intact patient tissue ex vivo. We developed a novel tumor slice model culture system that is universally applicable to gene delivery methods, using a realtime luminescence detection method to assess gene delivery. Methods investigated include viruses (adenovirus [Ad] and adeno-associated virus), lipofection, ultrasound (US), electroporation and naked DNA. Viability and tumor populations within the slices were well maintained for seven days, and gene delivery was qualitatively and quantitatively examinable for all vectors. Ad was the most efficient gene delivery vector with transduction efficiency >50%. US proved the optimal non-viral gene delivery method in human tumor slices. The nature of the ex vivo culture system permitted examination of specific elements. Parameters shown to diminish Ad gene delivery included blood, regions of low viability and secondary disease. US gene delivery was significantly reduced by blood and skin, while tissue hyperthermia improved gene delivery. US achieved improved efficacy for secondary disease. The ex vivo model was also suitable for examination of tissue-specific effects on vector expression, with Ad expression mediated by the CXCR4 promoter shown to provide a tumor selective advantage over the ubiquitously active cytomegalovirus promoter. In conclusion, this is the first study incorporating patient tissue models in comparing gene delivery from various vectors, providing knowledge on cell-type specificity and examining the crucial biological factors determining successful gene delivery. The results highlight the importance of in-depth preclinical assessment of novel therapeutics and may serve as a platform for further testing of current, novel gene delivery approaches.

VHL Genetic Alteration in CCRCC Does Not Determine De-regulation of HIF, CAIX, HnRNP A2/B1 and Osteopontin

Cellular Oncology (Dordrecht). Jun, 2011  |  Pubmed ID: 21547579

Von Hippel-Lindau (VHL) tumour suppressor gene inactivation is associated with clear cell renal cell carcinoma (CCRCC) development. The VHL protein (pVHL) has been proposed to regulate the expression of several proteins including Hypoxia Inducible Factor-α (HIF-α), carbonic anhydrase (CA)IX, heterogeneous nuclear ribonucleoprotein (hnRNP)A2/B1 and osteopontin. pVHL has been characterized in vitro, however, clinical studies are limited. We evaluated the impact of VHL genetic alterations on the expression of several pVHL protein targets in paired normal and tumor tissue.

Targeting of Breast Metastases Using a Viral Gene Vector with Tumour-selective Transcription

Anticancer Research. May, 2011  |  Pubmed ID: 21617219

Adeno-associated virus (AAV) vectors have significant potential as gene delivery vectors for cancer gene therapy. However, broad AAV2 tissue tropism results in nonspecific gene expression.

Induction of Effective Antitumor Response After Mucosal Bacterial Vector Mediated DNA Vaccination with Endogenous Prostate Cancer Specific Antigen

The Journal of Urology. Aug, 2011  |  Pubmed ID: 21683415

The induction of systemic immune responses against antigenic targets that are over expressed by cancer cells represents a powerful therapeutic strategy to target metastatic cancer. We generated specific antitumor immune responses in a murine model of prostate cancer by oral administration of an attenuated strain of Salmonella typhimurium containing a plasmid coding for murine prostate stem cell antigen.

Targeting Regulatory T Cells in Cancer

Cancer Research. Nov, 2011  |  Pubmed ID: 22068034

Infiltration of tumors by regulatory T cells confers growth and metastatic advantages by inhibiting antitumor immunity and by production of receptor activator of NF-κB (RANK) ligand, which may directly stimulate metastatic propagation of RANK-expressing cancer cells. Modulation of regulatory T cells can enhance the efficacy of cancer immunotherapy. Strategies include depletion, interference with function, inhibition of tumoral migration, and exploitation of T-cell plasticity. Problems with these strategies include a lack of specificity, resulting in depletion of antitumor effector T cells or global interruption of regulatory T cells, which may predispose to autoimmune diseases. Emerging technologies, such as RNA interference and tetramer-based targeting, may have the potential to improve selectivity and efficacy.

Deficits in Surgical Technical Performance: Prolonged Effects of Alcohol

Archives of Surgery (Chicago, Ill. : 1960). Dec, 2011  |  Pubmed ID: 22184315

High Resolution in Vivo Bioluminescent Imaging for the Study of Bacterial Tumour Targeting

PloS One. 2012  |  Pubmed ID: 22295120

The ability to track microbes in real time in vivo is of enormous value for preclinical investigations in infectious disease or gene therapy research. Bacteria present an attractive class of vector for cancer therapy, possessing a natural ability to grow preferentially within tumours following systemic administration. Bioluminescent Imaging (BLI) represents a powerful tool for use with bacteria engineered to express reporter genes such as lux. BLI is traditionally used as a 2D modality resulting in images that are limited in their ability to anatomically locate cell populations. Use of 3D diffuse optical tomography can localize the signals but still need to be combined with an anatomical imaging modality like micro-Computed Tomography (μCT) for interpretation.In this study, the non-pathogenic commensal bacteria E.coli K-12 MG1655 and Bifidobacterium breve UCC2003, or Salmonella Typhimurium SL7207 each expressing the luxABCDE operon were intravenously (IV) administered to mice bearing subcutaneous (s.c) FLuc-expressing xenograft tumours. Bacterial lux signal was detected specifically in tumours of mice post IV-administration and bioluminescence correlated with the numbers of bacteria recovered from tissue. Through whole body imaging for both lux and FLuc, bacteria and tumour cells were co-localised. 3D BLI and μCT image analysis revealed a pattern of multiple clusters of bacteria within tumours. Investigation of spatial resolution of 3D optical imaging was supported by ex vivo histological analyses. In vivo imaging of orally-administered commensal bacteria in the gastrointestinal tract (GIT) was also achieved using 3D BLI. This study demonstrates for the first time the potential to simultaneously image multiple BLI reporter genes three dimensionally in vivo using approaches that provide unique information on spatial locations.