Bcl-2与SIRT3通过整合细胞代谢-凋亡参与卵巢癌耐药机制的研究

Overexpression of the anti-apoptosis protein Bcl-2 was involved in drug resistance.Recent studies imply that Bcl-2 plays a dual role in the regulation of metabolic reprogramming and apoptosis.Our previous studies have found that the Bcl-2 inhibitor S1 was able to down-regulate the transcriptional level of glycolysis related genes, while inhibition of glycolysis could sensitize cells to the apoptosis induced by S1. These suggested that the role of Bcl-2 involved in apoptosis resistance may intertwine with its role participating in cancer cell metabolism reprogramming. Besides, there was a negative correlation between the expression level of protein Bcl-2 and SIRT3 in drug-resistant ovarian cancer cells. As a key regulator of Mitochondrial Protein Acetylation, NAD-dependent deacetylase SIRT3 regulates the mitochondria related metabolic pathways.Therefore, we initially speculated that inhibition of Bcl-2 may activate SIRT3 through altering the cell metabolism, while SIRT3 may regulate apoptosis through affecting glycolysis and mitochondrial oxidative phosphorylation pathway. To test this hypothesis, we observe the changes of glucose metabolism pattern in ovarian cancer cells through inhibiting Bcl-2,study the effects of SIRT3 on the metabolic reprogramming and apoptosis, and analyze the mechanisms involved in the integration of cell metabolism and apoptosis through SIRT3 and Bcl-2, providing a new way to overcome tumor drug resistance.

过表达Bcl-2引起的凋亡耐受是形成耐药的机制之一,近来发现Bcl-2具有调节细胞代谢与凋亡的双重作用。我们的实验发现Bcl-2抑制剂S1能够引起细胞糖酵解相关基因表达下调，而糖酵解抑制剂能够提高S1诱导的细胞凋亡敏感性。提示抑制Bcl-2诱导细胞凋亡与代谢重编程有关。我们还发现卵巢癌耐药细胞高表达Bcl-2，低表达线粒体去乙酰化酶SIRT3。作为线粒体蛋白乙酰化调节的主要因子，去乙酰化酶SIRT3活性依赖NAD+，参与了线粒体相关代谢途径的调节。因此，我们推测抑制Bcl-2可能改变癌细胞代谢，活化SIRT3，SIRT3通过细胞糖酵解及线粒体氧化磷酸化途径调控了细胞凋亡。为了验证这一假设，我们观察抑制Bcl-2诱导卵巢癌耐药细胞凋亡时，糖代谢表型的改变。检测SIRT3对代谢重编程及凋亡敏感性的影响，分析SIRT3与Bcl-2整合细胞代谢与凋亡的机制，为克服肿瘤耐药提供新的思路。

过表达Bcl-2引起的凋亡耐受是形成耐药的机制之一，近来发现Bcl-2具有调节细胞代谢与凋亡的双重作用。癌细胞代谢重编程与凋亡耐受、恶性生长、无限复制及血管生成等其他癌症特征标志之间的关系引起人们的关注，靶向调控癌细胞代谢可能成为一种新型的抗癌治疗手段。我们聚焦于人卵巢癌耐药细胞SKOV3/DDP独特的代谢模式，利用抗凋亡Bcl-2蛋白的抑制剂S1、ABT737，探讨抗凋亡Bcl-2蛋白通过整合细胞凋亡和代谢，参与顺铂耐药细胞代谢模式的调控机制。研究发现卵巢癌顺铂耐药细胞高表达Bcl-2可能与较高水平的氧化与抗氧化平衡、代谢重编程有关。Bcl-2抑制剂ABT737可能通过干扰卵巢癌耐药细胞的糖代谢、线粒体氧化磷酸化，影响氧化与抗氧化平衡等，导致线粒体功能障碍，增加了卵巢癌耐药细胞顺铂凋亡敏感性。SIRT3可能通过调节糖酵解关键酶HK-II在细胞中的定位，参与了Bcl-2抑制剂S1对卵巢癌细胞凋亡和代谢的调控; SIRT3可能是卵巢癌治疗过程中的新靶点，通过调节人卵巢癌细胞葡萄糖代谢过程，可发挥促进细胞死亡的作用。在二甲双胍的抗肿瘤过程中，去乙酰化酶SIRT3 通过扰乱线粒体功能造成能量应激等，形成能量应激-SIRT3 正反馈环路发挥促进凋亡作用。本研究针对肿瘤耐药细胞和非耐药细胞之间的代谢差异，提出了靶向抗凋亡Bcl-2蛋白的抑制剂S1、ABT737联合糖酵解抑制剂和增加化疗药物敏感性的新设想，为改善卵巢癌等恶性肿瘤的治疗提供理论依据。