The Fanconi anemia pathway sensitizes to DNA alkylating agents by inducing JNK-p53-dependent mitochondrial apoptosis in breast cancer cells.
The Fanconi anemia pathway sensitizes to DNA alkylating agents by inducing JNK-p53-dependent mitochondrial apoptosis in breast cancer cells.
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DOI：
10.3892/ijo.2014.2400
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发表时间：
2014-07
影响因子：
5.2
通讯作者：
Lin Zhao;Yanlin Li;Miao He;Zhiguo Song;Shu Lin;Zhaojin Yu;Xuefeng Bai;Enhua Wang;M. Wei
中科院分区：
文献类型：
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作者：
Lin Zhao;Yanlin Li;Miao He;Zhiguo Song;Shu Lin;Zhaojin Yu;Xuefeng Bai;Enhua Wang;M. Wei
Fanconi贫血/BRCA（FA/BRCA）DNA损伤修复途径在细胞对DNA烷化剂的反应中起着关键作用，并且极大地影响癌症治疗中的药物反应。然而，FA/BRCA途径逆转耐药的分子机制受到的关注有限。在本研究中，我们研究了Fanconi贫血互补组F蛋白（FANCF），FA/BRCA途径的关键因素，对DNA烷化剂，如丝裂霉素C（MMC）诱导的癌细胞凋亡的影响。我们发现FANCF shRNA增强MMC诱导的MCF-7和MDA-MB-231乳腺癌细胞的细胞毒性和凋亡。在机制水平上，FANCF shRNA下调抗凋亡蛋白Bcl-2和上调促凋亡蛋白Bax，伴随着MMC处理的细胞中cyt-c和smac释放到胞质溶胶中。此外，caspase-3和-9的激活，而不是caspase-8，多聚（ADP核糖）聚合酶（PARP）的切割，和线粒体膜电位（MMP）的降低表明线粒体凋亡途径参与MMC处理的乳腺癌细胞的FANCF沉默。在MMC处理的乳腺癌细胞中，还观察到FANCF沉默后IAP家族蛋白XIAP和生存素的减少。值得注意的是，FANCF shRNA能够通过激活MMC处理的乳腺癌细胞中的JNK通路来增加p53水平。此外，使用pifithrin-α抑制p53消除了FANCF shRNA和MMC对caspase-3和PARP的诱导，表明FANCF shRNA通过p53依赖性机制显著增强MMC诱导的细胞凋亡。据我们所知，我们为FANCF作为化疗增敏剂在乳腺癌治疗中的潜在应用提供了新的证据。
The Fanconi anemia/BRCA (FA/BRCA) DNA damage repair pathway plays a pivotal role in the cellular response to DNA alkylating agents and greatly influences drug response in cancer treatment. However, the molecular mechanisms underlying the FA/BRCA pathway reversed resistance have received limited attention. In the present study, we investigated the effect of Fanconi anemia complementation group F protein (FANCF), a critical factor of the FA/BRCA pathway, on cancer cell apoptosis induced by DNA alkylating agents such as mitomycin c (MMC). We found that FANCF shRNA potentiated MMC-induced cytotoxicity and apoptosis in MCF-7 and MDA-MB-231 breast cancer cells. At a mechanistic level, FANCF shRNA downregulated the anti-apoptotic protein Bcl-2 and upregulated the pro-apoptotic protein Bax, accompanied by release of cyt-c and smac into the cytosol in MMC-treated cells. Furthermore, activation of caspase-3 and -9, other than caspase-8, cleavage of poly(ADP ribose) polymerase (PARP), and a decrease of mitochondrial membrane potential (MMP) indicated that involvement of the mitochondrial apoptotic pathway in FANCF silencing of MMC-treated breast cancer cells. A decrease in IAP family proteins XIAP and survivin were also observed following FANCF silencing in MMC-treated breast cancer cells. Notably, FANCF shRNA was able to increase p53 levels through activation of the JNK pathway in MMC-treated breast cancer cells. Furthermore, p53 inhibition using pifithrin-α abolished the induction of caspase-3 and PARP by FANCF shRNA and MMC, indicating that MMC-induced apoptosis is substantially enhanced by FANCF shRNA via p53-dependent mechanisms. To our knowledge, we provide new evidence for the potential application of FANCF as a chemosensitizer in breast cancer therapy.