Hwang Geun Hye, Park So Mi, Han Ho Jae, Baek Kyoung Min, Kim Joong Sun, Chang Woochul, Lee Ho Jin, Yun Seung Pil, Ryu Jung Min, Lee Min Young
College of Pharmacy, Research Institute of Pharmaceutical Sciences, Kyungpook National University, Daegu 41566, Republic of Korea.
College of Veterinary Medicine, Seoul National University, Seoul 08826, Republic of Korea.
Oncol Lett. 2017 Nov;14(5):5484-5490. doi: 10.3892/ol.2017.6846. Epub 2017 Aug 28.
The present study examined the role of human cytochrome P450 2J2 (CYP2J2) on cell proliferation and resistance to an anticancer agent using stable hepatocellular carcinoma HepG2 cells overexpressing CYP2J2. Overexpression of CYP2J2 significantly increased HepG2 cell proliferation and the expression levels of cell cycle regulatory proteins, including cyclin D1, cyclin E, cyclin-dependent kinase (Cdk)2 and Cdk4. CYP2J2-overexpressing HepG2 cells exhibited high levels of Akt phosphorylation compared with those observed in wild-type HepG2 cells. Although Akt phosphorylation in both cell lines was significantly attenuated by LY294002, a specific phosphoinositide 3-kinase/Akt signaling inhibitor, the levels of Akt phosphorylation following treatment with LY294002 were higher in CYP2J2-overexpressing HepG2 cells than in wild-type HepG2 cells. Cell counting revealed that proliferation was reduced by LY294002 in both cell lines; however, CYP2J2-overexpressing HepG2 cell numbers were higher than those of wild-type HepG2 cells following treatment with LY294002. These results indicated that increased cell proliferation by CYP2J2 overexpression is mediated by increased Akt activity. It was also demonstrated that doxorubicin, an anticancer agent, reduced cell viability, induced a significant increase in the B-cell lymphoma (Bcl)-2 associated X protein (Bax)/Bcl-2 ratio and decreased pro-caspase-3 levels in wild-type HepG2 cells. However, the doxorubicin-induced reduction in cell viability was significantly attenuated by enhanced upregulation of CYP2J2 expression. The increase in the Bax/Bcl-2 ratio and the decrease in pro-caspase-3 levels were also recovered by CYP2J2 overexpression. In conclusion, CYP2J2 serves important roles in cancer cell proliferation and resistance to the anticancer agent doxorubicin in HepG2 cells.
本研究利用稳定过表达细胞色素P450 2J2（CYP2J2）的肝癌HepG2细胞，检测了人CYP2J2在细胞增殖及对抗癌药物耐药性方面的作用。CYP2J2的过表达显著增加了HepG2细胞的增殖以及细胞周期调节蛋白的表达水平，这些蛋白包括细胞周期蛋白D1、细胞周期蛋白E、细胞周期蛋白依赖性激酶（Cdk）2和Cdk4。与野生型HepG2细胞相比，过表达CYP2J2的HepG2细胞表现出高水平的Akt磷酸化。尽管用特异性磷酸肌醇3激酶/Akt信号抑制剂LY294002处理后，两种细胞系中的Akt磷酸化均显著减弱，但LY294002处理后，过表达CYP2J2的HepG2细胞中的Akt磷酸化水平高于野生型HepG2细胞。细胞计数显示，LY294002使两种细胞系的增殖均减少；然而，用LY294002处理后，过表达CYP2J2的HepG细胞数量高于野生型HepG2细胞。这些结果表明，CYP2J2过表达导致的细胞增殖增加是由Akt活性增强介导的。还证实，抗癌药物阿霉素降低了野生型HepG2细胞的活力，诱导B细胞淋巴瘤（Bcl）-2相关X蛋白（Bax）/Bcl-2比值显著升高，并降低了前半胱天冬酶-3水平。然而，CYP2J2表达的增强上调显著减弱了阿霉素诱导的细胞活力降低。CYP2J2的过表达也使Bax/Bcl-2比值的升高和前半胱天冬酶-3水平的降低得到恢复。总之，CYP2J2在HepG2细胞的癌细胞增殖及对抗癌药物阿霉素的耐药性中发挥重要作用。
