Abstract BNIP3 is a member of Bcl-2 protein family involved in regulation of various forms of cell death. However, its role in these processes remains unclear and varies depending on the type of cancer cells and environmental factors (pH, O 2 level, etc.). Here, the role of BNIP3 in apoptosis regulation in lung adenocarcinoma cells was investigated. The suppressed expression of BNIP3 caused inhibition of oxygen consumption and stimulated production of the mitochondrial reactive oxygen species, suggesting the role of BNIP3 in induction of mitochondrial dysfunction and its potential involvement in regulation of cell death. Indeed, cytochrome c release in the cells with BNIP3 knockout and knockdown was higher than in the wild-type (WT) upon apoptosis stimulation by cisplatin. Moreover, suppression of BNIP3 expression led to the increase in the caspase-3 activity and, as a consequence, accumulation of the apoptotic marker – p89 fragment of poly(ADP-ribose)-polymerase (PARP) – as compared to WT cells. Analysis of the SubG1 population by flow cytometry confirmed the elevated level of apoptosis in the BNIP3 knockout cells. Pretreatment with the antioxidant Trolox did not affect cell death, indicating that it was independent on reactive oxygen species. These data show that BNIP3 is involved in maintaining normal functioning of mitochondria and, as a result, can regulate the mitochondrial pathway of cell death.

中文翻译：

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BNIP3 作为顺铂诱导的细胞凋亡的调节剂

摘要 BNIP3 是 Bcl-2 蛋白家族的成员，参与调节各种形式的细胞死亡。然而，它在这些过程中的作用仍不清楚，并且因癌细胞的类型和环境因素（pH、O 2 水平等）而异。在这里，研究了 BNIP3 在肺腺癌细胞凋亡调节中的作用。BNIP3 的抑制表达导致氧消耗的抑制并刺激线粒体活性氧的产生，表明 BNIP3 在诱导线粒体功能障碍中的作用及其可能参与调节细胞死亡。事实上，在顺铂刺激细胞凋亡后，BNIP3 敲除和敲低的细胞中细胞色素 c 的释放高于野生型 (WT)。而且，BNIP3 表达的抑制导致 caspase-3 活性增加，因此，与 WT 细胞相比，凋亡标记物 - 聚（ADP-核糖）-聚合酶 (PARP) 的 p89 片段 - 的积累。通过流式细胞术对 SubG1 群体的分析证实了 BNIP3 敲除细胞的凋亡水平升高。用抗氧化剂 Trolox 预处理不影响细胞死亡，表明它不依赖于活性氧。这些数据表明，BNIP3 参与维持线粒体的正常功能，因此可以调节细胞死亡的线粒体途径。通过流式细胞术对 SubG1 群体的分析证实了 BNIP3 敲除细胞的凋亡水平升高。用抗氧化剂 Trolox 预处理不影响细胞死亡，表明它不依赖于活性氧。这些数据表明，BNIP3 参与维持线粒体的正常功能，因此可以调节细胞死亡的线粒体途径。通过流式细胞术对 SubG1 群体的分析证实了 BNIP3 敲除细胞的凋亡水平升高。用抗氧化剂 Trolox 预处理不影响细胞死亡，表明它不依赖于活性氧。这些数据表明，BNIP3 参与维持线粒体的正常功能，因此可以调节细胞死亡的线粒体途径。