MiR-34a inhibits proliferation and migration of breast cancer through down-regulation of Bcl-2 and SIRT1

MicroRNA-34a(miR-34a), a pivotal member of the p53 network, was found to be down-regulated in multiple types of tumors and further reported as a tumor suppressor microRNA. However, the profile and biological effects of miR-34a in breast cancer are still unclear. In this study, we aimed to determine the effect of miR-34a on the growth of breast cancer and to investigate whether its effect is achieved by targeting Bcl-2 and SIRT1. We examined miR-34a levels in breast cancer cell lines and breast cancer specimens by qRT-PCR. Proliferation assay, apoptosis assay, and morphological monitoring were performed to assess the tumor suppression effect of miR-34a in breast cancer cell lines. Western blotting was used to identify the targets of miR-34a. We also investigated the anti-tumor effects of the treatment combining miR-34a with 5-FU in breast cancer cells. We found that miR-34a expression was down-regulated in 5 breast cancer cell lines compared with the immortalized normal mammary epithelial cell line 184A1, and was also down-regulated by almost 50 % in breast cancer samples compared with their corresponding adjacent non-malignant breast tissues. Ectopic restoration of miR-34a in breast cancer cells suppressed cells proliferation, invasion, and induced apoptosis. Bcl-2 and SIRT1 as the targets of miR-34a were found to be in reverse correlation with ectopic expression of miR-34a. Furthermore, the treatment combining miR-34a with 5-FU significantly showed more efficient anti-tumor effects than single treatment of miR-34a or 5-FU. Since miR-34a functions as tumor suppressor microRNA in breast cancer, modulating miR-34a level in breast cancer was suggested to be a new and useful approach of breast cancer therapy.     

Transient B-Cell Depletion Combined With Apoptotic Donor Splenocytes Induces Xeno-Specific T- and B-Cell Tolerance to Islet Xenografts

Peritransplant infusion of apoptotic donor splenocytes cross-linked with ethylene carbodiimide (ECDI-SPs) has been demonstrated to effectively induce allogeneic donor-specific tolerance. The objective of the current study is to determine the effectiveness and additional requirements for tolerance induction for xenogeneic islet transplantation using donor ECDI-SPs. In a rat-to-mouse xenogeneic islet transplant model, we show that rat ECDI-SPs alone significantly prolonged islet xenograft survival but failed to induce tolerance. In contrast to allogeneic donor ECDI-SPs, xenogeneic donor ECDI-SPs induced production of xenodonor-specific antibodies partially responsible for the eventual islet xenograft rejection. Consequently, depletion of B cells prior to infusions of rat ECDI-SPs effectively prevented such antibody production and led to the indefinite survival of rat islet xenografts. In addition to controlling antibody responses, transient B-cell depletion combined with ECDI-SPs synergistically suppressed xenodonor-specific T-cell priming as well as memory T-cell generation. Reciprocally, after initial depletion, the recovered B cells in long-term tolerized mice exhibited xenodonor-specific hyporesponsiveness. We conclude that transient B-cell depletion combined with donor ECDI-SPs is a robust strategy for induction of xenodonor-specific T- and B-cell tolerance. This combinatorial therapy may be a promising strategy for tolerance induction for clinical xenogeneic islet transplantation.Pancreatic islet transplantation is a promising treatment option for type 1 diabetes (1). However, a major limitation to its widespread clinical application is the shortage of human donor pancreata (2,3). Xenogeneic sources of islets are an attractive alternative. Currently, porcine islets are considered the best suitable substitute for human transplantation because of the unlimited donor source and their functional compatibility in humans (4). Moreover, they may be resistant to recurrent autoimmunity that is potentially present in recipients of islet transplantation (5,6). Unfortunately, the need for aggressive immunosuppression to control xenogeneic rejection is currently prohibitive for its application as a standard therapy for β-cell replacement in humans (7,8). Therefore, effective tolerance strategies for xenogeneic transplantation are urgently needed.Early studies in xenogeneic transplant models point to a critical role of T-cell–mediated processes in xenograft rejection (7–10). However, B cells are increasingly recognized for their role in xenogeneic immunity (11,12). In addition to mediating humoral responses by differentiating into antibody-producing plasma cells, B cells have also been shown to influence T-cell priming, expansion, and differentiation through a variety of mechanisms, including antigen presentation, costimulation, and cytokine production (13–16). Consequently, B-cell deficiency or depletion ameliorates autoimmune diseases, including type 1 diabetes, multiple sclerosis, and rheumatoid or collagen-induced arthritis (17–19). Likewise, B-cell depletion has been demonstrated to prolong allogeneic and xenogeneic graft survival in nonhuman primates (12,20).We have previously shown that intravenous infusion of donor splenocytes cross-linked with ethylene carbodiimide (ECDI-SPs) induces donor-specific tolerance to allogeneic islet and heart grafts (21–23), and the mechanisms of graft protection in these models involve deletion, anergy, and regulation of T cells of direct and indirect allo-specificities (24).In the current study, we tested donor ECDI-SPs in a concordant (rat-to-mouse) xenogeneic islet transplant model. We show that although ECDI-SPs alone significantly prolong islet xenograft survival, additional transient B-cell depletion is required to promote xenogeneic tolerance and indefinite islet xenograft survival. Furthermore, transient B-cell depletion significantly impairs xenogeneic T-cell priming and memory T-cell generation. Reciprocally, during B-cell reconstitution after transient B-cell depletion, the recovered B cells exhibit xenoantigen-specific unresponsiveness in the long-term tolerized hosts. Collectively, our findings establish a novel and effective tolerance therapy for xenogeneic islet transplantation and underscore the critical role of B-cell depletion in this process.     

High mobility group-box 3 overexpression is associated with poor prognosis of resected gastric adenocarcinoma

AIM:To elucidate high mobility group-box 3(HMGB3) protein expression in gastric adenocarcinoma,its potential prognostic relevance,and possible mechanism of action.METHODS:Ninety-two patients with gastric adenocarcinomas surgically removed entered the study.HMGB3 expression was determined by immunohistochemistry through a tissue microarray procedure.The clinicopathologic characteristics of all patients were recorded,and regular follow-up was made for all patients.The inter-relationship of HMGB3 expression with histological and clinical factors was analyzed using nonparametric tests.Survival analysis was carried out by Kaplan-Meier(log-rank) and multivariate Cox(Forward LR) analyses between the group with overexpression of HMGB3 and the group with low or no HMGB3 ex-pression to determine the prognosis value of HMGB3 expression on overall survival.Further,HMGB3 expression was knocked down by small hairpin RNAs(shRNAs) in the human gastric cancer cell line BGC823 to observe its influence on cell biological characteristics.The MTT method was utilized to detect gastric cancer cell proliferation changes,and cell cycle distribution was analyzed by flow cytometry.RESULTS:Among 92 patients with gastric adenocarcinomas surgically removed in this study,high HMGB3 protein expression was detected in the gastric adenocarcinoma tissues vs peritumoral tissues(P 0.001).Further correlation analysis with patients' clinical and histology variables revealed that HMGB3 overexpression was obviously associated with extensive wall penetration(P = 0.005),a positive nodal status(P = 0.004),and advanced tumor-node-metastasis(TNM) stage(P = 0.001).But there was no correlation between HMGB3 overexpression and the age and gender of the patient,tumor localization or histologic grade.Statistical Kaplan-Meier survival analysis disclosed significant differences in overall survival between the HMGB3 overexpression group and the HMGB3 no or low expression group(P = 0.006).The expected overall survival time was 31.00 ± 3.773 mo(95%CI = 23.605-38.395) for patients with HMGB3 overexpression and 49.074 ± 3.648 mo(95%CI = 41.925-57.311) for patients with HMGB3 no and low-level expression.Additionally,older age(P = 0.040),extensive wall penetration(P = 0.008),positive lymph node metastasis(P = 0.005),and advanced TNM tumor stage(P = 0.007) showed negative correlation with overall survival.Multivariate Cox regression analysis indicated that HMGB3 overexpression was an independent variable with respect to age,gender,histologic grade,extent of wall penetration,lymph nodal metastasis,and TNM stage for patients with resectable gastric adenocarcinomas with poor prognosis(hazard ratio = 2.791,95%CI = 1.233-6.319,P = 0.019).In the gene function study,after HMGB3 was knocked down in the gastric cell line BGC823 by shRNA,the cell proliferation rate was reduced at 24 h,48 h and 72 h.Compared to BGC823 shRNA-negative control(NC) cells,the cell proliferation rate in cells that had HMGB3 shRNA transfected was significantly decreased(P 0.01).Finally,cell cycle analysis by FACS showed that BGC823 cells that had HMGB3 knocked down were blocked in G1/G0 phase.The percentage of cells in G1/G0 phase in BGC823 cells with shRNA-NC and with shRNA-HMGB3 was 46.84% ± 1.7%,and 73.03% ± 3.51% respectively(P = 0.001),whereas G2/M cells percentage decreased from 26.51% ± 0.83% to 17.8% ± 2.26%.CONCLUSION:HMGB3 is likely to be a useful prognostic marker involved in gastric cancer disease onset and progression by regulating the cell cycle.     

非淤胆型婴儿巨细胞病毒性肝炎治疗68例

目的:探讨非淤胆型婴儿巨细胞病毒性肝炎的治疗方法.方法:选择2008-01/2010-07本院儿科住院的68例非淤胆型婴儿巨细胞病毒性肝炎患儿,随机分为治疗组34例和对照组34例,均予复方甘草酸苷2 mL/(kg.次),1次/d,共3 wk.治疗组加用更昔洛韦5 mg/(kg.次),2次/d,2 wk;1次/d,1 wk.结果:治疗组和对照组总有效率分别为94.1%和91.1%,治疗3 wk复查肝功能指标结果提示丙氨酸氨基转移酶(ALT)、天门冬氨酸氨基转移酶(AST)、总胆红素(total bilirubin,T B I L)、谷氨酰转肽酶(g a m m a g l u t a m y ltranspeptidase,GGT)和碱性磷酸酶(alkalinephosphatase,ALP)指标较治疗前均明显下降,差异有显著意义(P<0.05);直接胆红素(directbilirubin,DBIL)、总胆汁酸(total bile acid,TBA)指标较治疗前均无明显变化,差异无显著意义(P>0.05).治疗前或治疗后2组间比较上述指标差异无显著意义(P>0.05).随访1年,失访5人,余患儿肝功能均正常;尿CMV-DNA,治疗组18人(54.5%)阳性,对照组15人(50.0%)阳性,差异无显著意义(P>0.05).结论:非淤胆型婴儿巨细胞病毒性肝炎不建议常规予更昔洛韦抗病毒治疗.