The C-terminal region of Bfl-1 sensitizes non-small cell lung cancer to gemcitabine-induced apoptosis by suppressing NF-κB activity and down-regulating Bfl-1Report as inadecuate




The C-terminal region of Bfl-1 sensitizes non-small cell lung cancer to gemcitabine-induced apoptosis by suppressing NF-κB activity and down-regulating Bfl-1 - Download this document for free, or read online. Document in PDF available to download.

Molecular Cancer

, 10:98

First Online: 16 August 2011Received: 06 January 2011Accepted: 16 August 2011

Abstract

Gemcitabine is used to treat several cancers including lung cancer. However, tumor cells often escape gemcitabine-induced cell death via various mechanisms, which include modulating bcl-2 family members and NF-κB activation. We previously reported that the C-terminal region of Bfl-1 fused with GFP BC is sufficient to induce apoptosis in 293T cells. In the present study, we investigated the anti-tumor effect of combined BC gene therapy and gemcitabine chemotherapy in vitro and in vivo using non-small cell lung cancer cell lines and a xenograft model. Cell lines were resistant to low dose gemcitabine 4-40 ng-ml, which induced NF-κB activation and concomitant up-regulation of Bfl-1 an NF-κB-regulated anti-apoptotic protein. BC induced the apoptosis of A549 and H157 cells with caspase-3 activation. Furthermore, co-treatment with BC and low dose gemcitabine synergistically and efficiently induced mitochondria-mediated apoptosis in these cells. When administered alone or with low dose gemcitabine, BC suppressed NF-κB activity, inhibited the nuclear translocation of p65-relA, and down-regulated Bfl-1 expression. Furthermore, direct suppression of Bfl-1 by RNA interference sensitized cells to gemcitabine-induced cell death, suggesting that Bfl-1 importantly regulates lung cancer cell sensitivity to gemcitabine. BC and gemcitabine co-treatment also showed a strong anti-tumor effect in a nude mouse-A549 xenograft model. These results suggest that lung cancer cells become resistant to gemcitabine via NF-κB activation and the subsequent overexpression of Bfl-1, and that BC, which has both pro-apoptotic and NF-κB inhibitory effects, could be harnessed as a gene therapy to complement gemcitabine chemotherapy in non-small cell lung cancer.

Keywordsgemcitabine NF-κB Bfl-1 gene therapy non-small cell lung cancer Abbreviations ListBCC-terminal region of Bfl-1 fused with GFP

NSCLCnon-small cell lung cancer

siRNAsmall interfering RNA.

Electronic supplementary materialThe online version of this article doi:10.1186-1476-4598-10-98 contains supplementary material, which is available to authorized users.

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Author: Min-Kyoung Kim - Yoon-Kyung Jeon - Jong-Kyu Woo - Yun Choi - Dae-Han Choi - Yeul-Hong Kim - Chul-Woo Kim

Source: https://link.springer.com/







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