Association between hepatitis B and E virus infection and hepatocellular carcinoma risk.

The role of hepatitis E virus (HEV) in developing hepatocellular carcinoma (HCC) is unclear. Our study aimed to investigate the role of HE infection in HCC development and the effect of hepatitis B virus (HBV) and HEV coinfection on HCC risk. A hospital-based case-control study was conducted. A total of 474 eligible HCC cases and 586 control patients were successfully recruited. The fasting venous blood was collected from the patients at the first visited to hospital and HBV infection and HEV infection were examined within 5 days. Crude and adjusted odd ratios (ORs) with 95% confidence interval (95% CI) were estimated by using logistic regression model. HBV infection (OR: 63.10, 95% CI: 42.02-97.26) rather than HEV infection (OR: 1.08, 95% CI: 0.721-1.65) was associated with an increased risk of HCC after adjustment for confounders. The association between HBV infection and HCC risk was more remarkable in male (OR: 72.61, 95% CI: 45.10-121.38) than in female (OR: 61.89, 95% CI: 25.74-169.26). In comparison with patients who infected with neither HEV nor HBV, those who infected with only HBV (OR: 69.62, 95% CI: 40.90-123.52) and who coinfected with HEV and HBV (OR: 67.48, 95% CI:37.23-128.19) were significantly associated with an increased risk after adjustment for potential confounders. The results showed that HBV infection rather than HEV infection was associated with an increased risk of HCC, and the HEV infection may alleviate the promoting impact of HBV on HCC development.

Hepatitis E virus re-infection accelerates hepatocellular carcinoma development and relapse in a patient with liver cirrhosis: A case report and review of literature.

BACKGROUND: Hepatitis E virus (HEV) superinfection is a suspected promoting factor for hepatocellular carcinoma (HCC) in patients with chronic hepatitis and cirrhosis. However, to date, very few cases of HEV-related HCC have been reported. Nevertheless, the role of HEV re-infection in cirrhotic liver without other chronic hepatitis infections has rarely been explored. CASE SUMMARY: A 53-year-old male farmer was diagnosed with liver cirrhosis and splenomegaly in August 2016, accompanied with negative HEV-IgM and positive HEV-IgG. No evidence of hepatitis B virus or hepatitis C virus infection was found. Since then the patient was evaluated for liver function and viral parameters every 3 mo. In June 2017, the patient presented severe fatigue with whole body itching and was diagnosed with HCC. Afterwards this patient experienced quick HCC development, progression, relapse, and metastasis in the following 8 mo, and presented persistent dual positivity of HEV-IgM and HEV-IgG. This patient had a long history of smoking and alcohol consumption. CONCLUSION: This unique case invokes the importance of HEV surveillance and treatment among cirrhotic patients, HCC cases, and blood donors.

Activation of miR-34a-5p/Sirt1/p66shc pathway contributes to doxorubicin-induced cardiotoxicity.

The molecular mechanisms underlying anthracyclines-induced cardiotoxicity have not been well elucidated. MiRNAs were revealed dysregulated in the myocardium and plasma of rats received Dox treatment. MicroRNA-34a-5p (miR-34a-5p) was verified increased in the myocardium and plasma of Dox-treated rats, but was reversed in rats received Dox plus DEX treatments. Human miR-34a-5p was also observed increased in the plasma of patients with diffuse large B-cell lymphoma after 9- and 16-week epirubicin therapy. Up-regulation of miR-34a-5p was observed in Dox-induced rat cardiomyocyte H9c2 cells. MiR-34a-5p could augment Bax expression, but inhibited Bcl-2 expression, along with the increases of the activated caspase-3 and mitochondrial potentials in H9C2 cells. MiR-34a-5p was verified to modulate Sirt1 expression post-transcriptionally. In parallel to Sirt1 siRNA, miR-34a-5p could enhance p66shc expression, accompanied by increases of Bax and the activated caspase-3 and a decrease of Bcl-2 in H9c2 cells. Moreover, enforced expression of Sirt1 alleviated Dox-induced apoptosis of H9c2 cells, with suppressing levels of p66shc, Bax, the activated caspase-3 and miR-34a-5p, and enhancing Bcl-2 expression. Therefore, miR-34a-5p enhances cardiomyocyte apoptosis by targeting Sirt1, activation of miR-34a-5p/Sirt1/p66shc pathway contributes to Dox-induced cardiotoxicity, and blockage of this pathway represents a potential cardioprotective effect against anthracyclines.

Population pharmacokinetics and safety of eptifibatide in healthy Chinese volunteers and simulations on the dose regimens approved for a Western population.

OBJECTIVE: This study was designed to evaluate the pharmacokinetics (PK) and safety of eptifibatide in healthy Chinese volunteers and provide information for the further study in the Chinese population. METHODS: 30 healthy volunteers (15 male) were enrolled in the study and divided into three dose groups (45 µg x kg⁻¹, 90 µg x kg⁻¹, and 180 µg x kg⁻¹). Plasma and urine samples were drawn after one single-bolus administration and measured by LC-MS/MS. The plasma and urine data were analyzed simultaneously by the population approach using the NONMEM software and evaluated by the visual predicted check (VPC) and bootstraping. The PK profiles of dose regimens approved for a Western population in the Chinese population were simulated. RESULTS: A two-compartment model adequately described the PK profiles of eptifibatide. The clearance (CL) and the distribution volume (V1) of the central compartment were 0.128 L x h⁻¹ x kg⁻¹ and 0.175 L x kg⁻¹, respectively. The clearance (Q) and V2of the peripheral compartment were 0.0988 L x h⁻¹ x kg⁻¹ and 0.147 L x kg⁻¹, respectively. The elimination fraction from plasma to urine (F0) was 17.2%. No covariates were found to have a significant effect. Inter-individual variabilites were all within 33.9%. The VPC plots and bootstrap results indicated good precision and prediction of the model. The simulations of the approved regimens in the Chinese population showed much lower steady-state concentrations than the target concentration obtained from the Western clinical trials. No severe safety events were found in this study. CONCLUSIONS: The PK model of eptifibatide was established and could provide PK information for further studies in the Chinese population.

Attenuation of microRNA-16 derepresses the cyclins D1, D2 and E1 to provoke cardiomyocyte hypertrophy.

Cyclins/retinoblastoma protein (pRb) pathway participates in cardiomyocyte hypertrophy. MicroRNAs (miRNAs), the endogenous small non-coding RNAs, were recognized to play significant roles in cardiac hypertrophy. But, it remains unknown whether cyclin/Rb pathway is modulated by miRNAs during cardiac hypertrophy. This study investigates the potential role of microRNA-16 (miR-16) in modulating cyclin/Rb pathway during cardiomyocyte hypertrophy. An animal model of hypertrophy was established in a rat with abdominal aortic constriction (AAC), and in a mouse with transverse aortic constriction (TAC) and in a mouse with subcutaneous injection of phenylephrine (PE) respectively. In addition, a cell model of hypertrophy was also achieved based on PE-promoted neonatal rat ventricular cardiomyocyte and based on Ang-II-induced neonatal mouse ventricular cardiomyocyte respectively. We demonstrated that miR-16 expression was markedly decreased in hypertrophic myocardium and hypertrophic cardiomyocytes in rats and mice. Overexpression of miR-16 suppressed rat cardiac hypertrophy and hypertrophic phenotype of cultured cardiomyocytes, and inhibition of miR-16 induced a hypertrophic phenotype in cardiomyocytes. Expressions of cyclins D1, D2 and E1, and the phosphorylated pRb were increased in hypertrophic myocardium and hypertrophic cardiomyocytes, but could be reversed by enforced expression of miR-16. Cyclins D1, D2 and E1, not pRb, were further validated to be modulated post-transcriptionally by miR-16. In addition, the signal transducer and activator of transcription-3 and c-Myc were activated during myocardial hypertrophy, and inhibitions of them prevented miR-16 attenuation. Therefore, attenuation of miR-16 provoke cardiomyocyte hypertrophy via derepressing the cyclins D1, D2 and E1, and activating cyclin/Rb pathway, revealing that miR-16 might be a target to manage cardiac hypertrophy.

Fn14 promotes differentiation of human mesenchymal stem cells into heart valvular interstitial cells by phenotypic characterization.

Despite the fact that tissue engineered heart valves (TEHV) hold great promise for heart valve disease treatment, one of the challenges is to find suitable seeding cells. Bone marrow derived mesenchymal stem cells (MSCs) were considered to be one of the best seed cell sources. In this study we propose a novel approach to promote stem cell differentiation into the seed cells of TEHV, valvular interstitial cells (VICs). Newly induced MSCs (iMSCs) were created from a co-culture niche in which healthy human donor derived MSCs were co-cultured with cardiac fibroblasts (H9C2 cell line). Then iMSCs were transfected with either a mock vector (iMSCs(mock) ) as controls or with a vector that overexpresses thefibroblast inducible factor 14 (Fn14) gene (iMSCs(Fn14) ). Immunofluorescence staining was performed to assay VIC differentiation. Western blot analysis was performed to analyze the involved signaling pathway. The results demonstrate that the expression of α-smooth muscle actin (SMA) was significantly higher in iMSCs(Fn14) as compared with iMSC(mock) , and MSC, and also had higher co-alignment of α-actinin and stress fiber (F-actin) in bundles. Additionally, increased biosynthesis of extracellular matrix (ECM) proteins including collagen I, collagen III, and fibronection were observed in iMSCs(Fn14) in comparison with iMSCs(mock) . These data observed in iMSCs(Fn14) were in accordance with VIC phenotype from normal heart valves. In addition, the PI3K/Akt signaling pathway was activated in iMSCs(Fn14) which allowed higher Akt phosphorylation (p-Akt) levels and SMA levels, whereas, it was attenuated by LY294002 (PI3K/Akt inhibitor). These new findings of the effect of Fn14 on VIC-like cell differentiation may provide a novel therapeutic strategy for heart valve disease treatment.

Smad3 inactivation and MiR-29b upregulation mediate the effect of carvedilol on attenuating the acute myocardium infarction-induced myocardial fibrosis in rat.

Carvedilol, a nonselective ß-adrenoreceptor antagonist, protects against myocardial injury induced by acute myocardium infarction (AMI). The mechanisms underlying the anti-fibrotic effects of carvedilol are unknown. Recent studies have revealed the critical role of microRNAs (miRNAs) in a variety of cardiovascular diseases. This study investigated whether miR-29b is involved in the cardioprotective effect of carvedilol against AMI-induced myocardial fibrosis. Male SD rats were randomized into several groups: the sham surgery control, left anterior descending (LAD) surgery-AMI model, AMI plus low-dose carvedilol treatment (1 mg/kg per day, CAR-L), AMI plus medium-dose carvedilol treatment (5 mg/kg per day, CAR-M) and AMI plus high-dose carvedilol treatment (10 mg/kg per day, CAR-H). Cardiac remodeling and impaired heart function were observed 4 weeks after LAD surgery treatment; the observed cardiac remodeling, decreased ejection fraction, and fractional shortening were rescued in the CAR-M and CAR-H groups. The upregulated expression of Col1a1, Col3a1, and α-SMA mRNA was significantly reduced in the CAR-M and CAR-H groups. Moreover, the downregulated miR-29b was elevated in the CAR-M and CAR-H groups. The in vitro study showed that Col1a1, Col3a1, and α-SMA were downregulated and miR-29b was upregulated by carvedilol in a dose-dependent manner in rat cardiac fibroblasts. Inhibition of ROS-induced Smad3 activation by carvedilol resulted in downregulation of Col1a1, Col3a1, and α-SMA and upregulation of miR-29b derived from the miR-29b-2 precursor. Enforced expression of miR-29b significantly suppressed Col1a1, Col3a1, and α-SMA expression. Taken together, we found that smad3 inactivation and miR-29b upregulation contributed to the cardioprotective activity of carvedilol against AMI-induced myocardial fibrosis.

Decreased expression of DAB2IP in pancreatic cancer with wild-type KRAS.

BACKGROUND: KRAS mutation plays an important role in the pathogenesis of pancreatic cancer. However, the role of wild-type KRAS in the progression of pancreatic cancer remains unknown. The present study was to investigate the expression of the Ras GTPase activating protein (DAB2IP) in pancreatic cancer and its clinical significance. METHODS: The expression of DAB2IP in pancreatic cancer cell lines and normal human pancreatic ductal epithelial cells was analyzed by Western blotting and real-time quantitative reverse transcription-PCR (qRT-PCR). The KRAS mutational types of pancreatic cancer tissues obtained from pancreatic cancer patients (n=20) were also analyzed. Subsequently, DAB2IP expression was detected in pancreatic cancer tissues, adjacent and normal pancreatic tissues (n=2) by immunohistochemistry, and the relationship between DAB2IP expression and the clinical characteristics of patients was evaluated. RESULTS: Western blotting and qRT-PCR results showed that DAB2IP expression in pancreatic cancer cells with wild-type KRAS was lower than that in those with mutation-type KRAS and normal human pancreatic ductal epithelial cells (P<0.05). Immunohistochemistry showed that DAB2IP expression was lower in pancreatic cancer tissues than that in adjacent and normal pancreatic tissues (Z=-4.000, P=0.000). DAB2IP expression was lower in pancreatic cancer patients with the wild-type KRAS gene than that in those with KRAS mutations (WilcoxonW=35.000, P=0.042). Furthermore, DAB2IP expression in patients with perineurial invasion was lower than that in those without invasion (WilcoxonW=71.500, P=0.028). DAB2IP expression was lower in patients with more advanced stage than that in those with early clinical stage (WilcoxonW=54.000, P=0.002). CONCLUSIONS: DAB2IP expression was reduced in patients with pancreatic cancer compared with those with no cancer. DAB2IP expression was correlated with the KRAS gene, perineurial invasion and clinical stage of the disease. Our data indicated that DAP2IP expression can be used as a potential prognostic indicator and a promising molecular target for therapeutic intervention in patients with pancreatic cancer.

Combinations of laminin 5 with PTEN, p-EGFR and p-Akt define a group of distinct molecular subsets indicative of poor prognosis in patients with non-small cell lung cancer.

Laminin 5 (Ln5) is an extracellular matrix protein that plays an important role in cell migration and tumor invasion. This study explored the expression of Ln5 and the role of its relationships with PTEN, phospho-EGFR (p-EGFR) and phospho-Akt (p-Akt) in the prognosis of patients with non-small cell lung cancer (NSCLC). The protein expression of Ln5, PTEN, p-EGFR and p-Akt was assessed by immunohistochemical analysis, and their relationships to prognosis were analyzed. Protein expression of Ln5, p-EGFR and p-Akt was detected in 61.2 (60/98), 60.2 (59/98) and 45.3% (43/95) of patients with NSCLC, respectively. Loss of PTEN expression was found in 67.7% of tumors (65/96). Ln5 expression was related to patient gender, histology and p-Akt expression (χ(2)=3.901, 4.549 and 6.985, respectively; P=0.048, 0.033 and 0.008, respectively). Patients with positive Ln5 expression had marginally poorer survival than Ln5-negative patients (median survival time 56.4 months vs. not reached; χ(2)=3.346; P=0.067). Overall survival was significantly different in patients with positive Ln5 expression combined with loss of PTEN, positive p-EGFR expression or positive p-Akt expression. Cox regression analysis showed that stage, co-expression of Ln5 and p-Akt, and PTEN were the three most independent prognostic factors for patients with NSCLC (χ(2)=27.906; P<0.0005). The results highlight the complex relationships between extracellular matrix proteins and key signaling pathway molecules in tumorigenesis. Changes in the expression of Ln5 plus PTEN, p-EGFR or p-Akt define a distinct subset of lung cancers. Patients with such cancers have poorer survival and require early treatment that impacts survival.

MicroRNA 16 enhances differentiation of human bone marrow mesenchymal stem cells in a cardiac niche toward myogenic phenotypes in vitro.

AIM: Upregulation of microRNA 16 (miR-16) contributed to the differentiation of human bone marrow mesenchymal stem cells (hMSCs) toward myogenic phenotypes in a cardiac niche, the present study aimed to determine the role of miR-16 in this process. MAIN METHODS: hMSCs and neonatal rat ventricular myocytes were co-cultured indirectly in two chambers to set up a cardiac microenvironment (niche). miRNA expression profile in cardiac-niche-induced hMSCs was detected by miRNA microarray. Cardiac marker expression and cell cycle analysis were determined in different treatment hMSCs. Quantitative real-time PCR and Western blot were used to identify the expression of mRNA, mature miRNA and protein of interest. KEY FINDINGS: miRNA dysregulation was shown in hMSCs after cardiac niche induction. miR-16 was upregulated in cardiac-niche-induced hMSCs. Overexpression of miR-16 significantly increased G1-phase arrest of the cell cycle in hMSCs and enhanced the expression of cardiac marker genes, including GATA4, NK2-5, MEF2C and TNNI3. Differentiation-inducing factor 3 (DIF-3), a G0/G1 cell cycle arrest compound, was used to induce G1 phase arrest in cardiac-niche-induced hMSCs, and the expression of cardiac marker genes was up-regulated in DIF-3-treated hMSCs. The expression of CCND1, CCND2 and CDK6 was suppressed by miR-16 in hMSCs. CDK6, CCND1 or CCND2 knockdown resulted in G1 phase arrest in hMSCs and upregulation of cardiac marker gene expression in hMSCs in a cardiac niche. SIGNIFICANCE: miR-16 enhances G1 phase arrest in hMSCs, contributing to the differentiation of hMSCs toward myogenic phenotypes when in a cardiac niche. This mechanism provides a novel strategy for pre-modification of hMSCs before hMSC-based transplantation therapy for severe heart diseases.

High levels of glucose induce "metabolic memory" in cardiomyocyte via epigenetic histone H3 lysine 9 methylation.

Diabetic patients continue to develop inflammation and cardiovascular complication even after achieving glycemic control, suggesting a "metabolic memory". Metabolic memory is a major challenge in the treatment of diabetic complication, and the mechanisms underlying metabolic memory are not clear. Recent studies suggest a link between chromatin histone methylation and metabolic memory. In this study, we tested whether histone 3 lysine-9 tri-methylation (H3K9me3), a key epigenetic chromatin marker, was involved in high glucose (HG)-induced inflammation and metabolic memory. Incubating cardiomyocyte cells in HG resulted in increased levels of inflammatory cytokine IL-6 mRNA when compared with myocytes incubated in normal culture media, whereas mannitol (osmotic control) has no effect. Chromatin immunoprecipitation (ChIP) assays showed that H3K9me3 levels were significantly decreased at the promoters of IL-6. Immunoblotting demonstrated that protein levels of the H3K9me3 methyltransferase, Suv39h1, were also reduced after HG treatment. HG-induced apoptosis, mitochondrial dysfunction and cytochrome-c release were reversible. However, the effects of HG on the expression of IL-6 and the levels of H3K9me3 were irreversible after the removal of HG from the culture. These results suggest that HG-induced sustained inflammatory phenotype and epigenetic histone modification, rather than HG-induced mitochondrial dysfunction and apoptosis, are main mechanisms responsible for metabolic memory. In conclusion, our data demonstrate that HG increases expression of inflammatory cytokine and decreases the levels of histone-3 methylation at the cytokine promoter, and suggest that modulating histone 3 methylation and inflammatory cytokine expression may be a useful strategy to prevent metabolic memory and cardiomyopathy in diabetic patients.

Induced bone marrow mesenchymal stem cells improve cardiac performance of infarcted rat hearts.

We investigated whether transplantation of bone marrow mesenchymal stem cells (BMSC) with induced BMSC (iBMSC) or uninduced BMSC (uBMSC) into the myocardium could improve the performance of post-infarcted rat hearts. BMSCs were specified by flowcytometry. IBMSCs were cocultured with rat cardiomyocyte before transplantation. Cells were injected into borders of cardiac scar tissue 1 week after experimental infarction. Cardiac performance was evaluated by echocardiography at 1, 2, and 4 weeks after cellular or PBS injection. Langendorff working-heart and histological studies were performed 4 weeks after treatment. Myogenesis was detected by quantitative PCR and immunofluorescence. Echocardiography showed a nearly normal ejection fraction (EF) in iBMSC-treated rats and all sham control rats but a lower EF in all PBS-treated animals. The iBMSC-treated heart, assessed by echocardiography, improved fractional shortening compared with PBS-treated hearts. The coronary flow (CF) was decreased obviously in PBS and uBMSC-treated groups, but recovered in iBMSC-treated heart at 4 weeks (P < 0.01). Immunofluorescent microscopy revealed co-localization of Superparamagnetic iron oxide (SPIO)-labeled transplanted cells with cardiac markers for cardiomyocytes, indicating regeneration of damaged myocardium. These data provide strong evidence that iBMSC implantation is of more potential to improve infarcted cardiac performance than uBMSC treatment. It will open new promising therapeutic opportunities for patients with post-infarction heart failure.

Posttreatment plasma VEGF levels may be associated with the overall survival of patients with advanced non-small cell lung cancer treated with bevacizumab plus chemotherapy.

We sought to find blood-based biomarkers that can be used to predict efficacy in advanced non-small cell lung cancer patients treated with bevacizumab plus chemotherapy. Blood was collected before treatment and after 6 weeks of therapy from patients who were participating in a phase 4 trial. Plasma vascular endothelial growth factor (VEGF) levels were evaluated by ELISA. A total of eight single nucleotide polymorphisms in four candidate genes were analyzed by PCR and sequencing. A total of 45 patients enrolled in a clinical trial at Guangdong General Hospital between August 2007 and March 2008 were used as subjects. The median survival times of OS was 25.6 and 13.4 months in the low and high groups, respectively, when the median posttreatment plasma VEGF level (46.63 pg/ml) was used as the cut-off point (P = 0.0284). Patients carrying the AA genotype at the -6C > A polymorphism in laminin 5 (LN5) were more likely to exhibit reduced hemoglobin compared with patients carrying the CA/CC genotype (OR = 8.364, χ(2) = 5.34, P = 0.021). Similar associations were found at the -89A > G and -260C > A polymorphisms in LN5. Patients with the CC genotype at the -6C > A polymorphism in LN5 had an increased risk of neutropenia than those with the CA/AA genotype (OR = 4.444, χ(2) = 5.116, P = 0.030). Our results show improved survival in patients with lower posttreatment plasma VEGF levels treated with bevacizumab plus chemotherapy; thus, the posttreatment plasma VEGF level may be a promising biomarker to predict clinical benefit early in the course of therapy. Polymorphisms in LN5 were associated with a reduced level of hemoglobin and neutropenia.

Ginsenoside-Rg1 mediates microenvironment-dependent endothelial differentiation of human mesenchymal stem cells in vitro.

Bone marrow-derived mesenchymal stem cells (MSCs) possess a multi-lineage differentiation potential and have the ability to repair and rebuild injured vessels. The autologous differentiated MSC transplantation also makes possible the tissue-engineered grafts. Therefore, the efficient endothelial differentiation of MSCs could be beneficial in the successful injured vessel repair and engraftment. Ginsenoside-Rg1, the most prevalent active constituent of ginseng, is a potent proangiogenic factor of vascular endothelial cells and also has the ability to enhance the proliferation of bone marrow cells. The aim of this study is to investigate the role of ginsenoside-Rg1 in the microenvironment-dependent endothelial differentiation of human MSCs (hMSCs) in vitro. The endothelial differentiation environment was established by co-culturing hMSCs with mature endothelial cells (human umbilical vein endothelial cells) indirectly in vitro. Reverse transcriptase-polymerase chain reaction analysis and fluorescence immunocytochemistry showed a strong expression of endothelial-specific markers such as CD31, Von Willebrand factor, and VE-cadherin. Electron microscopy showed the endothelial characteristic Weibel-Palade bodies of differentiated hMSCs. The increased expression of CD31 demonstrated that Rg1 promoted the endothelial differentiation of hMSCs. The findings here show the differentiation of hMSCs into cells with phenotypic features of endothelial cells using indirect co-culture with mature endothelial cells and provide the evidence that ginsenoside-Rg1 can promote the milieu-dependent endothelial differentiation of hMSCs in vitro.

In vitro sequence-dependent synergism between paclitaxel and gefitinib in human lung cancer cell lines.

PURPOSE: In clinical trials, the epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) administered concomitantly with first-line cytotoxicity chemotherapy failed to confer a survival benefit to patients with non-small-cell lung cancer (NSCLC). The aim of this study was to test whether paclitaxel followed by gefitinib is superior to other treatment schedules of NSCLC cell lines and to clarify the underlying mechanisms. METHODS: Human lung cancer cell lines with wild-type and mutant-type EGFR genes were used as in vitro models to define the differential effects of various schedules of paclitaxel with gefitinib treatment on cell growth, signaling pathway, and cell cycle distribution. RESULTS: Sequence-dependent antiproliferative effects differed between EGFR-TKI-resistant and EGFR-TKI-sensitive lung cancer cell lines. Exposure to paclitaxel resulted in an increased pEGFR level. This increase in phosphorylation was inhibited by subsequent exposure to gefitinib, whereas during the reverse sequence, the inhibition effect was reduced. After paclitaxel exposure, a higher level of pEGFR was observed in mitotic than in interphase cells. The sequence of paclitaxel followed by gefitinib resulted in greater anti-VEGF activity than did the reverse sequence. We confirmed that gefitinib arrested cells in G1, and paclitaxel arrested them in S phase. The sequence of paclitaxel followed by gefitinib arrested cells in G1, whereas the reverse sequence arrested cells in S and G2 phases. CONCLUSIONS: These findings suggest that the sequence of paclitaxel followed by gefitinib may be superior to other sequences in treating NSCLC cell lines. Our results also provide molecular evidence to support clinical treatment strategies for patients with lung cancer.

Transcription factor Ap-1 mediates proangiogenic MIF expression in human endothelial cells exposed to Angiotensin II.

Macrophage migration inhibitory factor (MIF) is an inflammatory cytokine associated with the atherosclerotic process and atherosclerotic plaque stability. MIF was shown to be highly expressed in advanced atherosclerotic lesions. Neutralizing MIF with a blocking antibody induced a regression of established atherosclerotic lesions. In this study, we investigated the mechanism underlying the proangiogenic effect of MIF in human umbilical vein endothelial cells (HUVECs). We showed that MIF induced the expression of angiogenesis-related genes in HUVECs. We also showed that MIF induced tube formation of HUVECs in vitro and in vivo. Angiotensin II (Ang II) could specifically up-regulate MIF expression in HUVECs. Using a luciferase reporter assay, we demonstrated that the AP-1 response element in the 5'-UTR of the MIF gene played a role in Ang II-induced MIF expression. Small hairpin RNA (shRNA) targeting c-Jun, a component of AP-1, and the AP-1 inhibitor CHX both efficiently inhibited MIF expression. The consistent result of electrophoretic mobility shift assay (EMSA) showed that Ang II specifically increased AP-1 activation in HUVECs. Our results suggest that AP-1 mediates Ang II-induced MIF expression which contributes to atherosclerotic plaque destabilization in human endothelial cells.

High levels of glucose induce apoptosis in cardiomyocyte via epigenetic regulation of the insulin-like growth factor receptor.

Diabetic hyperglycemia result in cardiovascular complications, but the mechanisms by which high levels of glucose (HG) cause diabetic cardiomyopathy are not known. We investigate whether HG-induced repression of insulin-like growth factor 1 receptor (IGF-1R) mediated by epigenetic modifications is one potential mechanism. We found that HG resulted in decreased IGF-1 receptor (IGF-1R) mRNA levels, and IGF-1R protein when compared with H9C2 rat cardiomyocyte cells incubated in normal glucose. HG also induced apoptosis of H9C2 cells. The effects of HG on reduced expression of IGF-1R and increased apoptosis were blocked by silencing p53 with small interference RNA but not by non-targeting scrambled siRNA. Moreover, HG negatively regulated IGF-1R promoter activity as determined by ChIP analysis, which was dependent on p53 since siRNA-p53 attenuated the effects of HG on IGF-1R promoter activity. HG also increased the association of p53 with histone deacetylase 1 (HDAC1), and decreased the association of acetylated histone-4 with the IGF-1R promoter. Furthermore, HDAC inhibitor relieved the repression of IGF-1R following HG state. These results suggest that HG-induced repression of IGF-1R is mediated by the association of p53 with the IGF-1R promoter, and by the subsequent enhanced recruitment of chromatin-modifying proteins, such as HDAC1, to the IGF-1R promoter-p53 complex. In conclusion, our data demonstrate that HG decreases expression of IGF-1R and decreases the association of acetylated histone-4 with the IGF-1R promoter. These studies may help delineate the complex pathways regulating diabetic cardiomyopathy, and have implications for the development of novel therapeutic strategies to prevent diabetic cardiomyopathy by epigenetic regulation of IGF-1R.

Improved liquid chromatography-tandem mass spectrometry method for the analysis of eptifibatide in human plasma.

A rapid, selective and highly sensitive high performance liquid chromatography-tandem mass spectrometry method (LC-MS/MS) was developed and validated for the determination and pharmacokinetic investigation of eptifibatide in human plasma. Eptifibatide and the internal standard (IS), EPM-05, were extracted from plasma samples using solid phase extraction. Chromatographic separation was performed on a C(18) column at a flow rate of 0.5 mL/min. Detection of eptifibatide and the IS was achieved by tandem mass spectrometry with an electrospray ionization (ESI) interface in positive ion mode. Traditional multiple reaction monitoring (MRM) using the transition of m/z 832.6-->m/z 646.4 and m/z 931.6-->m/z 159.4 was performed to quantify eptifibatide and the IS, respectively. The calibration curves were linear over the range of 1-1000 ng/mL with the lower limit of quantitation validated at 1 ng/mL. The intra- and inter-day precisions were within 13.3%, while the accuracy was within +/-7.6% of nominal values. The validated LC-MS/MS method was successfully applied for the evaluation of pharmacokinetic parameters of eptifibatide after intravenous (i.v.) administration of a 45 microg/kg bolus of eptifibatide to 8 healthy volunteers.

[Effect of ginsenoside Rg1 on the microenvironment dependent differentiation of human bone marrow mesenchymal stem cell to vaso-endothelioid formative cells in vitro].

OBJECTIVE: To investigate the effect of ginsenoside Rg1 on the microenvironment dependent differentiation of human mesenchymal stem cells (hMSCs) to vaso-endothelioid cells (VECs) in vitro. METHODS: The in vitro differentiation of hMSCs to VECs were established adopting the in vivo environment simulated semi-permeable membrane separated non-contact co-culturing method. The mRNA expressions of endothelial markers, such as platelet endothelial adhesive factor-1 (CD31), vascular hemophillia factor (vWF) and vascular endothelial cadherin (VE-cadherin) were analyzed by RT-PCR; the protein expressions of CD31 and vascular endothelial adhesive factor-1 (VCAM1) were detected by fluorescence immunohistochemistry; structural identification for the endothelial characteristics of differentiated hMSCs were made under electron microscopy; and the percentage of CD31 expression in differentiated hMSCs was determined by flow cytometry to explore the effect of ginsenoside Rg1 on the differentiation. RESULTS: The bone marrow mesenchymal stem cells co-cultured with mature endothelial membrane showed a microenvironment dependent capacity for differentiating to endothelium, with the morphological changes revealed starting from the 2nd week, showing cell body contraction, polygonal-shaped change; and at the 3rd week, the markedly speedily cell proliferation with elliptic or slabstone-like change of cells. High levels of classic endothelial cell markers, such as mRNA expressions of CD31, vWF, VE-cadherin, and protein expressions of CD31 and VCAM1, were shown; the typical weibel-palade body of endothelial cell was found in the differentiated cells. Moreover, percentage of CD31 expression in the differentiated hMSCs was increased after Rg1 treatment dose-dependently. CONCLUSION: Under the microenvironment of co-culture, hMSCs could differentiate into cells presenting the characteristics of endothelial cell in aspects of the morphology and ultrastructure of cells, as well as the gene and protein expressions of cell markers; ginsenoside Rg1 can promote the microenvironment dependent differentiation of hMSCs to VECs system in vitro.

[Efficacy comparison between transplanting microenvironmental induced and non-induced bone marrow mesenchymal stem cells in ischemic rat hearts].

OBJECTIVE: To compare the efficacy of transplanting bone marrow mesenchymal stem cell (BMSC) or microenvironmental induced BMSC (iBMSC) into the ischemic myocardium of rats with myocardial infarction. METHODS: iBMSC was defined as BMSC co-cultured with myocardial cells for 2 weeks. The stem cells or equal volume PBS were injected into ischemic border zone 1 wk after experimental infarction. Cardiac performance was evaluated at 1, 2, and 4 wk after cell transplantation by echocardiography and analyzed histologically at 4 wk after cell transplantations. RESULTS: Compared with PBS group, both BMSC and iBMSC transplantations reduced infarct size. iBMSC enhanced the beneficial effects of BMSC on improving cardiac function (FS: 28.5% +/- 4.3% in PBS, 29.0% +/- 2.0% in BMSC and 45.1% +/- 3.1% in iBMSC group at 4 weeks post transplantation, iBMSC group vs. PBS group P < 0.05, iBMSC group vs. BMSC group P < 0.05). Immunofluorescence microscopy results revealed co-localization of SPIO-labeled transplanted cells with cardiac markers for cardiomyocytes, indicating regeneration of damaged myocardium. CONCLUSION: Our data suggest that iBMSC implantation is more effective on improving cardiac function than BMSC implantation in this model. iBMSC might serve as a new promising therapeutic cell source for regenerating ischemic myocardium in patients with post-infarction heart failure.