Theranostic nanoparticles based on superparamagnetic iron oxide (SPIO) have a great promise for tumor diagnosis and gene therapy. However, the availability of theranostic nanoparticles with efficient gene transfection and minimal toxicity remains a big challenge. In this study, we construct an intelligent SPIO-based nanoparticle comprising a SPIO inner core and a disulfide-containing polyethylenimine (SSPEI) outer layer, which is referred to as a SSPEI-SPIO nanoparticle, for redox-triggered gene release in response to an intracellular reducing environment. We reveal that SSPEI-SPIO nanoparticles are capable of binding genes to form nano-complexes and mediating a facilitated gene release in the presence of dithiothreitol (5-20 mM), thereby leading to high transfection efficiency against different cancer cells. The SSPEI-SPIO nanoparticles are also able to deliver small interfering RNA (siRNA) for the silencing of human telomerase reverse transcriptase genes in HepG2 cells, causing their apoptosis and growth inhibition. Further, the nanoparticles are applicable as T2-negative contrast agents for magnetic resonance (MR) imaging of a tumor xenografted in a nude mouse. Importantly, SSPEI-SPIO nanoparticles have relatively low cytotoxicity in vitro at a high concentration of 100 ?g/mL. The results of this study demonstrate the utility of a disulfide-containing cationic polymer-decorated SPIO nanoparticle as highly potent and low-toxic theranostic nano-system for specific nucleic acid delivery inside cancer cells.
MicroRNAs (miRNAs) are strongly implicated in many cancers, including papillary thyroid carcinoma (PTC), which is the most common malignancy in thyroid tissue. Recently, miRNA-155 (miR-155) has been proved to play a substantial role in liposarcoma and breast cancer, but its functions in the context of PTC remain unknown.
Glucokinase (GCK) is the key glucose phosphorylation enzyme which has attracted considerable attention as a candidate gene for type 2 diabetes (T2D) based on its enzyme function as the first rate-limiting step in the glycolysis pathway and regulates glucose-stimulated insulin secretion. In the past decade, the relationship between GCK and T2D has been reported in various ethnic groups. To derive a more precise estimation of the relationship and the effect of factors that might modify the risk, we performed this meta-analysis.
MicroRNAs are single-stranded noncoding RNAs composed of approximately 22 nucleotides that suppress gene expression by selectively binding via base-pairing to the complementary 3-untranslated region (3-UTR) of messenger RNA transcripts. Protein kinase C epsilon (PKC?) is an important modulating member of the transducing Ras/Raf-1 signal pathway; a computational search revealed miR-146a putatively binds to the 3-UTR of the PRKCE gene, and thus decreasing PKC? expression. Moreover, PKC? inhibits mitochondrial apoptosis and is associated with the Bcl family. However, it has been previously reported that miR-146a expression in papillary thyroid carcinoma (PTC) is slightly elevated. Thus, we hypothesized that because miR-146a expression depends on nuclear factor kappaB (NF-?B) activation and NF-?B expression is elevated in PTC, miR-146a is potentially upregulated in PTC via negative feedback of NF-?B, and thus suppressing PKC? expression. In our study, we investigated whether overexpression of miR-146a, a tumor-suppressing-miR, in PTC cells decreases cell survival and induces apoptosis. Luciferase reporter assay analysis confirmed the direct binding of miR-146a and PRKCE 3-UTR. Specific overexpression of exogenous miR-146a significantly decreased PKC? levels in PTC cell line NPA-187 and increased apoptosis. Additionally, using stably expressing miR-146a thyroid carcinoma cells to establish subcutaneous tumors, the tumor growth exhibited significant inhibition. Our study confirmed the tumor-suppressing role of miR-146a in thyroid carcinoma cells and contributes to the knowledge regarding modulation of Ras/Raf-1 signal transduction and apoptosis via PKC? targeted by miR-146a in PTC; moreover, our findings confirmed that miR-146a is involved in the feedback system of the classical NF-?B signal pathway in PTC.
Although Berberine (BER) is popular in treating gastrointestinal (GI) disorders, its mechanisms are not clear yet. In order to investigate the effects and possible mechanism of BER on GI motility in rodents, we first explored GI motility by recording the myoelectrical activity of jejunum and colon in rats, and upper GI transit with a charcoal marker in mice. Then, the plasma levels of gastrin, motilin, somatostatin and glucagon-like-peptide-1 (Glp-1) were measured by ELISA or radioimmunoassay (RIA). Furthermore, endogenous opioid-peptides (?-endorphin, dynorphin-A, met-enkephalin) were detected by RIA after treatment with BER. Our results showed that BER concentration-dependently inhibited myoelectrical activity and GI transit, which can be antagonized by opioid-receptor antagonists to different extents. The elevated somatostatin and Glp-1, and decreased gastrin and motilin in plasma, which were caused by BER application, also could be antagonized by the opioid-receptor antagonists. Additionally, plasma level of ?-endorphin, but not dynorphin-A and met-enkephalin, was increased by applying BER. Taken together, these studies show that BER plays inhibiting roles on GI motility and up-regulating roles on somatostatin, Glp-1 and down-regulating roles on gastrin, motilin. The pharmacological mechanisms of BER on GI motility and plasma levels of GI hormones were discovered to be closely related to endogenous opioid system.
The (99m)Tc-labeled agent, ((99m)TcO)depreotide, has received regulatory approval in the United States and Europe for use in the detection of cancer. It is essential to establish a simple and reliable method of direct radiolabeling of (99m)Tc-depreotide and to investigate its specific receptor binding properties with human non small cell lung cancer (NSCLC) A549 cell in vitro. So we made some researches as follow: Depreotide was labeled with (99m)Tc using SnCl2 as a reductant. Labeling efficiencies at different pH values and temperatures were compared. Radioreceptor assay was used to observe the uptake kinetics, stagnation and retention half time of (99m)Tc-depreotide in A549 cells. As the results of the investigation ,many facts is shown below: The labeling rate of pH 6.0 group was higher than that of pH 5.0 and pH7.0 groups. The labeling rate decreased when temperature increased from 15 °C to 50 °C. The uptake rate increased with rising temperature, and the maximum uptake was observed at 60 min at 37 °C. The cleaning curves were similar at different temperatures, and the half cleaning time at 37 °C was 48 min. The results showed that the optimal conditions for labeling depreotide with (99m)Tc was found to be below 15 °C at a pH lower than 6.0. Furthermore, at 37 °C, (99m)Tc-depreotid may have the potential as an ideal imaging agent for somatostatin receptors.
Serum cytokines are promising biomarkers of cancer staging and outcome prediction, including response to treatment. Serum samples were collected from 200 breast carcinoma patients prior to chemotherapy treatment. Luminex liquid protein chip technology was used to analyze 25 cytokines in serum. Linear regression was used to analyze the relationship of cytokine levels and tumor size. The independent sample T-test and Chi-square test methods were used to analyze the difference of cytokine levels between two groups. IL-12p40, sIL-2R, MMP-2 levels showed linear correlation with tumor size. Eotaxin, IL-10, IL-12p70, IL-7, IL-1ra, IP-10, MCP-1beta, MP-2 and MIP-1beta levels showed significant difference between different lymph node groups, but only Eotaxin, IP-10 and MCP-1 levels had an inverse correlation with the number of positive nodes. Fractalkine, G-CSF, MIP-1alpha, MIP-1beta levels showed significant differences between different ER+ groups. Eotaxin, Fractalkine, IL-6, IL-7, IL-10, MCP-1 and VEGF levels had significant differences between different HER-2 groups. Our study resulted in the identification of a serum cytokine profile with the potential to be clinically applicable to predict disease outcome and in monitoring of efficacy of treatment.
The aim of this study was to validate the accuracy of left ventricular ejection fraction (LVEF) obtained by quantitative gated single photon emission tomography (QGS) perfusion imaging in comparison with gated blood-pool imaging. Resting gated myocardial perfusion imaging was performed in 269 patients with suspected or known coronary artery disease, and followed by equilibrium nuclear cardiac blood-pool imaging in one week. The later was considered as the reference standard. The LVEF from both methods were analyzed. The LVEF were calculated with QGS using Cedars Cardiac Quantification software. We found that LVEF from QGS and blood-pool (Bp)-LVEF were highly correlated (r=0.819, <0.001). Taken into consideration that QGS-LVEF was significantly different from Bp-LVEF (mean ± SD: 57.77% ± 19.28% vs 54.23% ± 15.41%, P<0.05), data were further analyzed by grouping participants based on end-systolic ventricular volume (ESV). QGS-LVEF was not significantly different from Bp-LVEF in the group where that ESV was larger than 15m, (mean ± SD: 52.71% ± 16.11% vs 51.83% ± 15.33%, P>0.05), whereas when ESV was smaller than 15 mL, QGS-LVEF was significantly higher than Bp-LVEF (mean ± SD: 80.53% ± 7.01%vs 65.06% ± 10.37%, P<0.05). Our findings demonstrate that when ESV values are larger than 15 mL, QGS- LVEF could replace Bp-LVEF. However, when ESV value is smaller than 15 mL, LVEF should be assessed in combination with blood-pool imaging.
The effect of thiazolidinediones (TZDs) on bone mineral density (BMD) and bone metabolism in patients with type 2 diabetes is still in debate. Accumulating evidence has emerged that long-term administration of TZDs may increase the occurrence of osteoporosis, at least in postmenopausal women. Because little clinical data has been reported on Chinese people, a retrospective study was performed. One-hundred ninety-eight Chinese people, all from our inpatients, were selected for a 24-28 month review (26 +/- 0.5 m). Four groups divided according to gender and TZD use were designated fTZD, mTZD, f and m. Changes of subjects BMD and bone metabolism markers were noted and analyzed. Compared with group f, bone loss from fTZD in this over 24-month review was more significant in lumbar spine (L1-L4) (0.1 +/- 0.15 vs. 0.06 +/- 0.11) and right hip (0.09 +/- 0.15 vs. 0.05 +/- 0.14) (g/cm(3)) (P < 0.05). However, the opposite result was found in male patients with less bone loss in group mTZD. Two bone metabolism markers, including beta C-terminal telopeptide of type I collagen (beta-CTX) and osteocalcin (OC), in this study did not prove valuable in revealing changes among groups. We concluded that long-term TZD use may increase the risk of bone loss in Chinese postmenopausal patients with type 2 diabetes, which may provide caution on drug treatment in clinical practice. Whether TZD can protect male patients against BMD loss or not awaits further research.
A polymeric cisplatin(IV) prodrug in the form of cross-linked micelles (M(Pt(IV)) was prepared by first constructing MPEG-b-PCL-b-PLL micelles and then attaching a cisplatin(IV) complex with two axial succinic moieties to the lysine residues of the carrier polymer in aqueous medium. The micelles obtained were characterized by TEM, DLS, and zeta potential measurement. Their in vitro release experiments were carried out at pH 7.4 and 5.0 or in the presence of 5mM sodium ascorbate (NaAsc). Results showed that the micelles were sensitive to both acidic hydrolysis and mild reducing agents; in the presence of 5mM NaAsc, cisplatin(II) was directly released and the released cisplatin(II) could chelate with nucleobases; the micelles displayed comparable cytotoxicities to cisplatin; and the micelles were much more efficiently internalized by the cells than cisplatin(II) and cisplatin(IV) counterparts. Moreover, in vivo study showed accumulation of more Pt species in the tumor site and lower systematic toxicity compared to free cisplatin(II) and cisplatin(IV). This polymeric prodrug of cisplatin is expected to be used more for future study and applications.
A biodegradable and amphiphilic copolymer, poly(ethylene glycol)-block-poly(l-lactide-co-2-methyl-2-carboxyl-propylene carbonate) (mPEG-b-P(LA-co-MCC)), which contains pendant carboxyl groups, was chosen as a drug carrier for the active anticancer part (diaminocyclohexane platinum, DACH-Pt) of oxaliplatin to form mPEG-b-P(LA-co-MCC/Pt) complex. A folic acid-conjugated copolymer, folic acid-poly(ethylene glycol)-block-poly(L-lactide) (FA-PEG-PLA), with similar chemical structure was chosen for targeting. Multifunctional micelles were successfully prepared by a coassembling method. In vitro evaluation was performed by using SKOV-3 and MCF-7 cancer cells. In vivo blood clearance of platinum was studied, and the results show that micelles exhibit longer blood circulation after iv injection. Pt biodistribution was studied by measuring its levels in plasma, organs, and tumors, especially in tumor cell DNA, by atomic absorption and inductively coupled plasma mass spectrometry. Antitumor activity was assessed in mice bearing H22 liver cancers, and the results showed that the micelles with FA moieties exhibited greater antitumor efficacy than those without FA or oxaliplatin. Therefore, these novel multifunctional platinum micelles have great potential in future clinical application.
A strategy of preparing composite micelles containing both cisplatin(IV) prodrug and paclitaxel was developed, i.e., synthesizing a cisplatin(IV) conjugate and a paclitaxel conjugate starting with the same biodegradable and amphiphilic block copolymer, and co-assembling the two conjugates. The composite micelles could release effective anticancer drug cisplatin(II) upon cellular reduction and PTX via acid hydrolysis once they came into the cancerous cells. Moreover, the composite micelles displayed synergistic effect in vitro and the combination therapy in micellar dosage-form led to reduced systematic toxicity and enhanced antitumor efficacy in vivo.
Hsp90 interacts with proteins that mediate signaling pathways involved in the regulation of essential processes such as proliferation, cell cycle control, angiogenesis and apoptosis. Hsp90 inhibition is therefore an attractive strategy for blocking abnormal pathways that are crucial for cancer cell growth. In the present study, the role of Hsp90 in human breast cancer MCF-7 cells was examined by stably silencing Hsp90 gene expression with an Hsp90-silencing vector (Hsp90-shRNA). RT-PCR and Western blot analyses showed that Hsp90-shRNA specifically and markedly down-regulated Hsp90 mRNA and protein expression. NF-kB and Akt protein levels were down-regulated in Hsp90-shRNA transfected cells, indicating that Hsp90 knockout caused a reduction of survival factors and induced apoptosis. Treatment with Hsp90-shRNA significantly increased apoptotic cell death and caused cell cycle arrest in the G1/S phase in MCF-7 cells, as shown by flow cytometry. Silencing of Hsp90 also reduced cell viability, as determined by MTT assay. In vivo experiments showed that MCF-7 cells stably transfected with Hsp90-shRNA grew slowly in nude mice as compared with control groups. In summary, the Hsp90-shRNA specifically silenced the Hsp90 gene, and inhibited MCF-7 cell growth in vitro and in vivo. Possible molecular mechanisms underlying the effects of Hsp90-shRNA include the degradation of Hsp90 breast cancer-related client proteins, the inhibition of survival signals and the upregulation of apoptotic pathways. shRNA-mediated interference may have potential therapeutic utility in human breast cancer.
Indoleamine 2,3-dioxygenase (IDO) converts tryptophan to l-kynurenine, and it is noted as a relevant molecule in promoting tolerance and suppressing adaptive immunity. In this study, to investigate the effects of IDO in carbon tetrachloride (CCl(4) )-induced hepatitis model, the levels of IDO enzymic activities in the mock group, the control group and the 1-methyl-D-tryptophan (1-MT)-treated group were confirmed by determination of l-kynurenine concentrations. Serum alanine aminotransferase levels in 1-MT-treated rats after CCl(4) injection significantly increased compared with those in mock and control groups. In CCl(4)-induced hepatitis models, tumour necrosis factor-? (TNF-?) is critical in the development of liver injury. The mRNA expression and secretion levels of TNF-? in the liver from 1-MT-treated rats were more enhanced compared with those in the mock and the control groups. Moreover, the levels of cytokine and chemokine from mock, control group and 1-MT-treated rats after treated with CCl(4) were analyzed by ELISA, and the level of interleukin-6 was found to increase in 1-MT-treated rats. It was concluded that the deficiency of IDO exacerbated liver injury in CCl(4)-induced hepatitis and its effect may be connected with TNF-? and interleukin-6.
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