过表达 PTEN 增强肝癌 HepG2细胞对吉非替尼的敏感性

目的：探索过表达 PTEN 增强 HepG2细胞对吉非替尼敏感性的分子机制。方法：脂质体法转染获得稳定表达野生型 PTEN、磷酸酶缺失 PTEN 和空质粒 pcDNA3.1的肝癌 HepG2细胞株，MTT 法检测各组转染细胞对吉非替尼的药物敏感性，流式细胞仪检测吉非替尼诱导各组转染细胞的凋亡情况，Western blot 分析各组转染细胞 PTEN、Akt、pAkt 和 Caspase -3表达情况。结果：与转染 pcDNA3.1的对照组细胞相比，稳定转染PTEN 的 HepG2细胞对吉非替尼的敏感性显著增加（ P <0.05）。吉非替尼作用48h 后，稳定转染 PTEN 的HepG2细胞凋亡率明显高于对照组（P <0.05）。过表达 PTEN 可以抑制 Akt 磷酸化，促进 Caspase -3表达。而转染磷酸酶缺失 PTEN 的 HepG2细胞丧失上述生物学行为。结论：PTEN 可能通过抑制 Akt 信号通路、诱导细胞凋亡来增强细胞对吉非替尼的敏感性。

Overexpression of PTEN enhances the sensitivity of human hepatocellular carcinoma HepG2 cells to gefitinib

Objective:To explore the effect of PTEN overexpression on sensitivity of human hepatocellular carcino-ma HepG2 cells to gefitinib and its molecular mechanism. Methods:The wildtpye PTEN,phosphatase - deficient PTEN mutant and empty vector(pcDNA3. 1)were transducted into HepG2 cells by liposome transfection. The effect of PTEN on the sensitivity and cell apoptosis of transfected HepG2 cells treated by gefitinib were detected by MTT as-say and FACS assay. The expression of PTEN,Akt,pAkt,Caspase - 3 of transfected HepG2 was detected by Western blot. Results:Compared to HepG2 cells transfected into pcDNA3. 1,the sensitivity of HepG2 cells transfected into PTEN to gefitinib significantly increased( P < 0. 05). Meanwhile,apoptosis rates of HepG2 cells transfected into PTEN treated by gefitnib for 48h were significantly increased. Overexpression of PTEN was able to inhibit phosphoryl-ation of Akt and promote expression of Caspase - 3. However,HepG2 cells transfected into phosphatase - deficient PTEN mutant lost the above biological behaviors. Conclusion:PTEN could enhance the sensitivity of HepG2 cells to gefitinib by inhibiting Akt signal pathway and inducing apoptosis.