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ABSTRACT: BH3 (Bcl-2 homology domain 3)-only proteins have an important role in the cisplatin resistance of cells. However, the effect of BH3-only proteins on cisplatin-resistant ovarian cancer cells has not been thoroughly elucidated. Our results from the present study indicate that Puma plays a critical role in the apoptosis of chemo-resistant ovarian cancer cells treated with BetA (betulinic acid). The reduction of Puma expression inhibits Bax activation and apoptosis. However, p53 gene silencing has little effect on Puma activation. Further experiments demonstrated that Akt-mediated FoxO3a (forkhead box O3a) nuclear translocation and the JNK (c-Jun N-terminal kinase)/c-Jun pathway only partially trigger Puma induction and apoptosis, whereas dominant-negative c-Jun expression with FoxO3a reduction completely inhibits Puma expression and cell death. Furthermore, our results suggest that JNK regulates the Akt/FoxO3a signalling pathway. Therefore the dual effect of JNK can efficiently trigger Puma activation and apoptosis in chemoresistant cells. Taken together, our results demonstrate the role of Puma in BetA-induced apoptosis and the molecular mechanisms of Puma expression regulated by BetA during ovarian cancer cell apoptosis. Our findings suggest that the JNK-potentiated Akt/FoxO3a and JNK-mediated c-Jun pathways co-operatively trigger Puma expression, which determines the threshold for overcoming chemoresistance in ovarian cancer cells.
Biochemical Journal 03/2012; 444(2):291-301. · 4.90 Impact Factor
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Zhiwei Zhao,
Yaqin Yao,
Zhenyu Ding,
Xi Chen,
Ke Xie,
Yan Luo,
Jiaming Zhang,
Xiancheng Chen,
Xiaohua Wu,
Jianrong Xu, [......],
Ting Niu,
Jiyan Liu,
Qiu Li,
Wei Zhang,
Yanjun Wen,
Jingmei Su,
Bing Hu,
Hong Bu,
Yuquan Wei,
Yang Wu
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ABSTRACT: Anti-angiogenesis represents an indispensible strategy for cancer therapy. As a strictly endothelial-specific adhesion molecule, vascular endothelial cadherin (VE-cadherin, VE-cad) is a promising anti-angiogenesis target. In this study a recombinant adenovirus vector modified with mannan was used to deliver VE-cad (AdVEC-m) and we tried to explore its feasibility as an antitumour agent in mouse cancer models. The immunogenic delivery of VE-cad resulted in obvious prophylactic and therapeutic inhibition of tumour growth and prolonged survival in mice. In the meantime angiogenesis declined apparently within the tumours measured by immunohistochemistry staining and coated alginate bead assay in vivo. Anti-VE-cad antibodies were identified by western blot analysis and enzyme-linked immunosorbent assay (ELISA). VE-cad-specific T lymphocyte cytotoxicity responses (CTL) were detected by chromium (51Cr) release assay of splenocytes from AdVEC-m treated mice. These results demonstrate that mannan modification is able to enhance antigen delivery and immune responses, and the way of immunogenic delivery (AdVEC-m) is expected to provide an attractive vaccine strategy for cancer immunotherapy.
Vaccine 06/2011; 29(25):4218-24. · 3.77 Impact Factor
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ABSTRACT: Chemo-resistance to cisplatin-centered cancer therapy is a major obstacle to the effective treatment of human ovarian cancer. Previous reports indicated that arsenic trioxide (ATO) induces cell apoptosis in both drug-sensitive and -resistant ovarian cancer cells.
In this study, we determined the molecular mechanism of ATO-induced apoptosis in ovarian cancer cells. Our data demonstrated that ATO induced cell apoptosis by decreasing levels of phosphorylated AKT (p-AKT) and activating caspase-3 and caspase-9. Importantly, BIM played a critical role in ATO-induced apoptosis. The inhibition of BIM expression prevented AKT dephosphorylation and inhibited caspase-3 activation during cell apoptosis. However, surprisingly, gene silencing of AKT or FOXO3A had little effect on BIM expression and phosphorylation. Moreover, the activation of caspase-3 by ATO treatment improved AKT dephosphorylation, not only by cleaving the regulatory A subunit of protein phosphatase 2A (PP2A), but also by increasing its activation. Furthermore, our data indicated that the c-Jun N-terminal kinases (JNK) pathway is involved in the regulation of BIM expression.
We demonstrated the roles of BIM in ATO-induced apoptosis and the molecular mechanisms of BIM expression regulated by ATO during ovarian cancer cell apoptosis. Our findings suggest that BIM plays an important role in regulating p-AKT by activating caspase-3 and that BIM mediates the level of AKT phosphorylation to determine the threshold for overcoming cisplatin resistance in ovarian cancer cells.
PLoS ONE 01/2011; 6(5):e20586. · 4.09 Impact Factor
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ABSTRACT: PNAS-4 has been demonstrated to induce apoptosis in U2OS cells. To evaluate its feasibility as a new strategy for cancer therapy, we analyzed its anti-tumor effect with or without gemcitabine in A549 lung cancer cells. MTT assay, Hoechst 33258 staining and flow cytometric analysis were used to determine the cytotoxicity of PNAS-4 alone or plus gemcitabine. The anti-tumor efficacy was further investigated in vivo with nude mice. PNAS-4 plasmid/liposome complexes were injected by tail vein every 4 days. Gemcitabine was given ip on a weekly schedule for 4 weeks. PNAS-4 alone and plus gemcitabine induced apoptosis in A549 cells in vitro. The xenograft lung cancer treated with PNAS-4 retarded growth compared with the empty vector. The combination of PNAS-4 with gemcitabine induced anti-tumor activity accompanied by an increase in apoptotic cells compared with PNAS-4 or gemcitabine alone. No other obvious toxicity was found. PNAS-4 therefore suppresses tumor growth in vivo and enhances sensitivity to gemcitabine. This suggests that the PNAS-4 gene could be a potential candidate for lung cancer therapy alone or in combination with gemcitabine.
Cell Biology International 01/2009; 33(3):276-82. · 1.48 Impact Factor
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Jiong Li,
Kaijun Cui,
Jing Wen, Zhiwei Zhao,
Ping Chen,
Ling Tian,
Bing Kan,
Yanjun Wen,
Hongxin Deng,
Linyu Fan,
Yuquan Wei
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ABSTRACT: A DNA fragment encoding human interleukin 4 was obtained by PCR from pORF-hIL4 plasmid. The amplified fragment was inserted into prokaryotic expression vector PQE60 and recombinant protein was expressed in E. Coli M15 by adding isopropyl-beta-D-thiogalactoside (IPTG). The hIL-4 protein was present as insoluble inclusion bodies in the bacterial extract. After denaturation of inclusion bodies with 5 mol/L guanidine hydrochloride, the supernate was diluted to get renaturized. Then dialysis and Ni chelating chromatography were used for purification. TF-1 proliferation assay of recombinant human interleukin 4 was performed, and then rhIL-4 was fit to be used for proliferation of human dendritic cells from monocyte in vitro.
Sheng wu yi xue gong cheng xue za zhi = Journal of biomedical engineering = Shengwu yixue gongchengxue zazhi 09/2007; 24(4):866-9.
