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Background: MicroRNA-449a is a tumor suppressor that is down-regulated in multiple tumors types. However, the role of miR-449a in gastric cancer (GC) remains largely unknown. Methods: MiR-449a expression was up-regulated using miR-449a mimics, and the role of miR-449a in GC was assessed using cell viability and apoptosis assays. miR-449a target genes were confirmed using luciferase activity, RT-PCR and western blot assays. Results: miR-449a was downregulated in gastric cancer cell lines and gastric cancer tissues. Restoration of miR-449a expression inhibited gastric cancer cell proliferation and colony formation. Significant G0/G1 arrest was observed in gastric cancer cells transfected with miR-449a mimics. Furthermore, combination therapy with miR-449a with cisplatin displayed greater anti-tumor effects than treatment with cisplatin alone. We also identified E2F3 (E2F transcription factor 3), an important transcription factor involved in the proliferation and metastasis of tumor cells, as a direct target gene of miR-449a. Furthermore, silencing E2F3 elicits similar a repressive effect as overexpression of miR-449a in gastric cancer cells, and E2F3 overexpression rescued the repressing effects of miR-449a mimics. Conclusions: This study indicates that the miR-449a/E2F3 axis plays an important role in proliferation and apoptosis in gastric cancer. Therefore, miR-449a represents a novel target for gastric cancer therapy.

The N-myc downstream-regulated gene 2 (NDRG2) is involved in cell differentiation and apoptosis, but its function in the pancreas remains to be established. Herein we examine the expression and function of NDRG2 in the endocrine pancreas. NDRG2 immunoreactivity was localized mainly in the cytoplasm of pancreatic beta cells. When beta-TC3 cells were exposed chronically to high levels of free fatty acid (FFA), cell viability was impaired, and Akt and NDRG2 phosphorylation were reduced. NDRG2 is a potential substrate of protein kinase Akt. Overexpression of constitutively active Akt enhanced NDRG2 phosphorylation and abolished the apoptosis induced by FFA in beta-TC3 cells, whereas NDRG2 knock-down attenuated Akt-mediated protection of beta cells against fatty acid-triggered apoptosis. Collectively, these data indicate that NDRG2 acts as a key molecule in pancreatic beta cells and is involved in the Akt-mediated protection of beta cells against lipotoxicity.

Glioblastoma multiforme (GBM) is the most common and lethal primary brain tumor in adults. Despite advances in standard therapy, including surgical resection followed by radiation and chemotherapy, the prognosis for patients with GBM remains dismal, with a median survival time of

Breast cancer is the most common malignancy in women in the world. High incidence and poor clinical outcomes underly the need for a better understanding of its tumor biology and how to effectively inhibit tumor progression. In the present study the question of whether NDRG2 might be a useful target for breast cancer therapy was addressed. With the increase or decrease of NDRG2 levels in MCF-7 and Bcap-37 cells by adenovirus-NDRG2 infection or NDRG2 siRNA transfection, CD24 expression was significantly decreased or increased, respectively. Furthermore, NDRG2 overexpression suppressed breast cancer cell adhesion and invasion, whereas knockdown of NDRG2 promoted these events. In conclusion, the data from the current study indicated that NDRG2, the product of a tumor suppressor gene, can regulate CD24 expression to decrease the metastatic potential of breast cancer cells.

Abnormal high activation of survivin is involved in carcinogenesis of various types of cancer. Survivin has been shown to promote cell proliferation in human hepatocellular carcinoma (HCC). Survivin-targeting approaches have become a promising strategy for treating HCC. Here, we used a reporter system to screen effective survivin siRNA sequences. The effect of vector-based survivin short hairpin RNA (shRNA) on the malignant phenotype of HCC cells in vitro and in vivo was determined, and an adenovirus-mediated shRNA expression vector was developed to decrease survivin expression of the established HCC tumor in nude mice. In vitro study showed that stable survivin knockdown inhibited cancer cell proliferation, enhanced apoptotic susceptibility, arrested cell cycle in the G1 phase and resulted in apparent mitotic catastrophe. Moreover, cells stably expressing survivin shRNA showed decreased tumorigenicity in nude mice. An additional in vivo study showed that intratumoral injection of adenovirus-delivered survivin shRNA suppressed tumor growth by spontaneous apoptosis of cancer cells and significantly prolonged animal survival. In conclusion, we proved the therapeutic potential of survivin shRNA for the treatment of HCC. And our results indicated that adenovirus-delivered shRNA may serve as a novel therapeutic for HCC.

To study the effect of Triptolide (TL) on the growth of prostate carcinoma cell line, and analyze its function and mechanism in anti-prostate cancer.MTT experiments were performed to examine the inhibiting effect of TL on the proliferation of RM-1 cells, cell morphological changes observed by acridine staining, cellular cycles and apoptosis peak analyzed by flow cytometry, the apoptosis fracture zone investigated with DNA electrophoresis, and the expressions of caspase-3 and bcl-2 mRNA in RM-1 cells examined by RT-PCR.The results of MTT experiments showed that after the treatment of TL (5, 10, 20, 40 and 80 ng/ml), the RM-1 cell proliferation inhibition rates were 9.8%, 25.1%, 39.2%, 48.8% and 53.2% respectively; 12, 24, 36 and 48 hours after the treatment of TL (10 and 20 ng/ml), the cell proliferation inhibition rates were 8.4%, 25.1%, 36.1%, 42.4% and 10.2%, 39.2%, 50.2% and 58.5% respectively. Acridine staining after the TL treatment revealed nucleus condensation, cell membrane invagination, irregular orange particles in the cells and apoptosis morphological changes; flow cytometry tests showed that 48 hours after the TL treatment (10, 20 ng/ml) of RM-1 cells, an obvious apoptosis peak appeared before the G1 stage; 24, 36 and 48 hours after it, DNA "trapezoid" strips could be seen; the caspase-3 mRNA expression in the TL treated cells was higher, and the bcl-2 mRNA expression was lower than in the controls.TL can decrease bcl-2 expression, increase caspase-3 expression, induce apoptosis of prostate carcinoma cells, and consequently inhibit the proliferation of RM-1 cells in mice.