Introduction. Selective embolization of the left-gastric artery (LGA) reduces levels of ghrelin and achieves significant short-term weight loss. However, embolization of the LGA would prevent the performance of bariatric procedures because the high-risk leakage area (gastroesophageal junction [GEJ]) would be devascularized. Aim. To assess an alternative vascular approach to the modulation of ghrelin levels and generate a blood flow manipulation, consequently increasing the vascular supply to the GEJ. Materials and methods. A total of 6 pigs underwent a laparoscopic clipping of the left gastroepiploic artery. Preoperative and postoperative CT angiographies were performed. Ghrelin levels were assessed perioperatively and then once per week for 3 weeks. Reactive oxygen species (ROS; expressed as ROS/mg of dry weight [DW]), mitochondria respiratory rate, and capillary lactates were assessed before and 1 hour after clipping (T0 and T1) and after 3 weeks of survival (T2), on seromuscular biopsies. A celiac trunk angiography was performed at 3 weeks. Results. Mean (±standard deviation) ghrelin levels were significantly reduced 1 hour after clipping (1902 ± 307.8 pg/mL vs 1084 ± 680.0; P = .04) and at 3 weeks (954.5 ± 473.2 pg/mL; P = .01). Mean ROS levels were statistically significantly decreased at the cardia at T2 when compared with T0 (0.018 ± 0.006 mg/DW vs 0.02957 ± 0.0096 mg/DW; P = .01) and T1 (0.0376 ± 0.008mg/DW; P = .007). Capillary lactates were significantly decreased after 3 weeks, and the mitochondria respiratory rate remained constant over time at the cardia and pylorus, showing significant regional differences. Conclusions. Manipulation of the gastric flow targeting the gastroepiploic arcade induces ghrelin reduction. An endovascular approach is currently under evaluation.
Novel therapies employing oncolytic viruses have emerged as promising anticancer modalities. The cure of particularly aggressive malignancies requires induction of immunogenic cell death (ICD), coupling oncolysis with immune responses via calreticulin, ATP, and high-mobility group box protein B1 (HMGB1) release from dying tumor cells. The present study shows that in human pancreatic cancer cells (pancreatic ductal adenocarcinoma [PDAC] cells n=4), oncolytic parvovirus H-1 (H-1PV) activated multiple interconnected death pathways but failed to induce calreticulin exposure or ATP release. In contrast, H-1PV elevated extracellular HMGB1 levels by 4.0±0.5 times (58%±9% of total content; up to 100 ng/ml) in all infected cultures, whether nondying, necrotic, or apoptotic. An alternative secretory route allowed H-1PV to overcome the failure of gemcitabine to trigger HMGB1 release, without impeding cytotoxicity or other ICD activities of the standard PDAC medication. Such broad resistance of H-1PV-induced HMGB1 release to apoptotic blockage coincided with but was uncoupled from an autocrine interleukin-1? (IL-1?) loop. That and the pattern of viral determinants maintained in gemcitabine-treated cells suggested the activation of an inflammasome/caspase 1 (CASP1) platform alongside DNA detachment and/or nuclear exclusion of HMGB1 during early stages of the viral life cycle. We concluded that H-1PV infection of PDAC cells is signaled through secretion of the alarmin HMGB1 and, besides its own oncolytic effect, might convert drug-induced apoptosis into an ICD process. A transient arrest of cells in the cyclin A1-rich S phase would suffice to support compatibility of proliferation-dependent H-1PV with cytotoxic regimens. These properties warrant incorporation of the oncolytic virus H-1PV, which is not pathogenic in humans, into multimodal anticancer treatments.
Cell therapy based on alloreactivity has completed clinical proof of concept against hematological malignancies. However, the efficacy of alloreactivity as a therapeutic approach to treat solid tumors is unknown. Using cell culture and animal models, we aimed to investigate the efficacy and safety of allogeneic suicide gene-modified killer cells as a cell-based therapy for hepatocellular carcinoma (HCC), for which treatment options are limited. Allogeneic killer cells from healthy donors were isolated, expanded, and phenotypically characterized. Antitumor cytotoxic activity and safety were studied using a panel of human or murine HCC cell lines engrafted in immunodeficient or immunocompetent mouse models. Human allogeneic suicide gene-modified killer cells (aSGMKCs) exhibit a high, rapid, interleukin-2-dependent, and non-major histocompatibility complex class I-restricted in vitro cytotoxicity toward human hepatoma cells, mainly mediated by natural killer (NK) and NK-like T cells. In vivo evaluation of this cell therapy product demonstrates a marked, rapid, and sustained regression of HCC. Preferential liver homing of effector cells contributed to its marked efficacy. Calcineurin inhibitors allowed preventing rejection of allogeneic lymphocytes by the host immune system without impairing their antitumor activity. Our results demonstrate proof of concept for aSGMKCs as immunotherapy for HCC and open perspectives for the clinical development of this approach.
Hepatocellular carcinoma (HCC) is one of the most common cancer related deaths worldwide. One of the main challenges in cancer treatment is drug delivery to target cancer cells specifically. Preclinical evaluation of intratumoral drugs in orthotopic liver cancer mouse models is difficult, as percutaneous injection hardly can be precisely performed manually. In the present study we have characterized a hepatoma model developing a single tumor nodule by implantation of Hep55.1C cells in the liver of syngeneic C57BL/6J mice. Tumor evolution was followed up by µCT imaging, and at the histological and molecular levels. This orthotopic, poorly differentiated mouse HCC model expressing fibrosis, inflammation and cancer markers was used to assess the efficacy of drugs. We took advantage of the high precision of a previously developed robotized system for automated, image-guided intratumoral needle insertion, to administer every week in the tumor of the Hep55.1C mouse model. A significant tumor growth inhibition was observed using our robotized system, whereas manual intraperitoneal administration had no effect, by comparison to untreated control mice.
The development of imaging devices adapted to small animals has opened the way to image-guided procedures in biomedical research. In this paper, we focus on automated procedures to study the effects of the recurrent administration of substances to the same animal over time. A dedicated system and the associated workflow have been designed to percutaneously position a needle into the abdominal organs of mice. Every step of the procedure has been automated: the camera calibration, the needle access planning, the robotized needle positioning, and the respiratory-gated needle insertion. Specific devices have been developed for the registration, the animal binding under anesthesia, and the skin puncture. Among the presented results, the system accuracy is particularly emphasized, both in vitro using gelose phantoms and in vivo by injecting substances into various abdominal organs. The study shows that robotic assistance could be routinely used in biomedical research laboratories to improve existing procedures, allowing automated accurate treatments and limited animal sacrifices.
Animal experimentation is a prerequisite for preclinical evaluation of treatments such as chemotherapy. Its strictly regulated with the purpose of reducing the number of experimental animal as well as their pain. Small animal imaging should provide a painless longitudinal follow up of tumor progression on a single animal. The aim of the study is to validate small animal imaging by microscanner (?scan) in longitudinal follow up of a hepatocellular carcinoma (HCC) and to demonstrate its interest for in vivo evaluation of tumor response to different therapeutics. An HCC model achieved by orthotopic graft of the MH3924A cell line in ACI rats was followed using a Imtek/Siemens microscanner (?scan) with contrast agents (Fenestra(®) LC/VC). The procedures giving the optimal enhancement of the liver as well as a reliable determination of tumor volumes by ?scan were validated. Three protocols for therapeutic assessment through ?scan longitudinal follow up were performed. Each consisted in three groups testing a chemotherapy (gemcitabine, gemcitabine-oxaliplatine or sorafenib) versus two control groups (placebo and doxorubicine). Comparison was done on tumor volumes, median and actual survivals. There was a significant correlation between tumor volumes measured by ?scan and autopsy. Treatment by sorafenib, at the contrary of gemcitabine alone or with oxaliplatine, resulted in a significant reduction in tumor volumes and prolongation of actuarial survival. These results are consistent with available clinical data for these diverse therapeutics. In conclusion, small animal imaging with ?scan is a non-invasive, reliable, and reproducible method for preclinical evaluation of antitumor agents.
Myo-inositol trispyrophosphate (ITPP), a synthetic allosteric effector of hemoglobin, increases the regulated oxygen-releasing capacity of red blood cells (RBCs), leading to suppression of hypoxia-inducible factor 1? (HIF-1?) and to down-regulation of hypoxia-inducible genes such as vascular endothelial growth factor (VEGF). As a consequence, tumor growth is markedly affected. The effect of weekly intravenous injection of ITPP on an orthotopic, syngenic rat hepatocellular carcinoma (HCC) model was compared to that for untreated animals and animals subjected to conventional Doxorubicin chemotherapy. The longitudinal examination of HCC was performed by microCT imaging, and the cellular and molecular changes were evaluated by histology and Western blotting analysis of HIF-1?, VEGF, and caspase-3 gene expression in the tumor and in the surrounding liver. Hematologic impact was evaluated by blood cell-count measurement and determination of P50 (oxygen partial pressure for a 50 % oxygen saturation of hemoglobin). The HCC evaluation by microCT revealed a high potency of ITPP for tumor growth inhibition, thus allowing long-term survival and even cure of almost all the treated animals. The P50 value of hemoglobin in RBCs underwent a shift of 30 % following ITPP injection. Under these conditions, HIF-1? activity was strongly decreased, VEGF expression was down-regulated, and apoptosis was induced in HCC and surrounding liver cells, as indicated by Caspase-3 expression. ITPP did not affect hematologic parameters during treatment. The observations of in vivo tumor eradication suggest a significant clinical potential for ITPP in cancer therapy.
The transcriptional activity of nuclear retinoic acid receptors (RARs) relies on the association/dissociation of coregulators at the ligand-binding domain. However, we determined that the N-terminal domain (NTD) also plays a role through its phosphorylation, and we isolated vinexin?, a cytoskeleton protein with three SH3 domains, as a new partner of the RAR? NTD. Here we deciphered the mechanism of the interaction and its role in RAR?-mediated transcription. By combining molecular and biophysical (surface plasmon resonance, NMR, and fluorescence resonance energy transfer) approaches, we demonstrated that the third SH3 domain of vinexin? interacts with a proline-rich domain (PRD) located in RAR? NTD and that phosphorylation at a serine located in the PRD abrogates the interaction. The affinity of the interaction was also evaluated. In vivo, vinexin? represses RAR?-mediated transcription and we dissected the underlying mechanism in chromatin immunoprecipitation experiments performed with F9 cells expressing RAR? wild type or mutated at the phosphorylation site. In the absence of retinoic acid (RA), vinexin? does not occupy RAR? target gene promoters and sequesters nonphosphorylated RAR? out of promoters. In response to RA, RAR? becomes phosphorylated and dissociates from vinexin?. This separation allows RAR? to occupy promoters. This is the first report of an RAR corepressor association/dissociation out of promoters and regulated by phosphorylation.
The present study investigated the molecular mechanism of silibinin-induced antitumoral effects in hepatocarcinoma Hep-55.1C cells in vitro and in a hepatocarcinoma model in mice.
Related JoVE Video
Journal of Visualized Experiments
What is Visualize?
JoVE Visualize is a tool created to match the last 5 years of PubMed publications to methods in JoVE's video library.
How does it work?
We use abstracts found on PubMed and match them to JoVE videos to create a list of 10 to 30 related methods videos.
Video X seems to be unrelated to Abstract Y...
In developing our video relationships, we compare around 5 million PubMed articles to our library of over 4,500 methods videos. In some cases the language used in the PubMed abstracts makes matching that content to a JoVE video difficult. In other cases, there happens not to be any content in our video library that is relevant to the topic of a given abstract. In these cases, our algorithms are trying their best to display videos with relevant content, which can sometimes result in matched videos with only a slight relation.