目的 研究醉茄素A通过Janus激酶（JAK）/信号转导与转录激活子（STAT）通路对人肝癌耐药细胞HepG2/阿霉素（ADM）凋亡的影响，并探讨JAK/STAT通路在其中可能的作用机制。方法 体外培养HepG2/ADM细胞，分为对照组、醉茄素A 2.5、5.0、10.0 μmol/L组。CCK-8法检测细胞增殖情况；Hoechst33342染色法观察细胞形态学变化；Annexin V-FITC/PI双染色法检测细胞凋亡情况；Western blotting法检测凋亡相关蛋白B淋巴细胞瘤-2（Bcl-2）、cleaved caspase-3以及JAK/STAT通路中磷酸化JAK2（p-JAK2）、STAT3（p-STAT3）蛋白表达情况。结果 醉茄素A 2.5、5.0、10.0 μmol/L组HepG2/ADM细胞增殖受到明显抑制，并呈时间和剂量相关性（P<0.05）。与对照组相比，醉茄素A 2.5、5.0、10.0 μmol/L组HepG2/ADM细胞部分细胞核发生碎片化、固缩，荧光强度增大，细胞凋亡指数及凋亡率显著升高（P<0.05），cleaved caspase-3蛋白表达水平显著升高（P<0.05），Bcl-2、p-JAK2、p-STAT3蛋白表达水平显著降低（P<0.05）。结论 醉茄素A可促进人肝癌耐药细胞HepG2/ADM凋亡，其机制可能与抑制JAK/STAT通路活化，下调抑凋亡蛋白表达及上调促凋亡蛋白表达有关。

Objective To study the effect of withaferin A on apoptosis of HepG2/ADM cells through Janus kinase (JAK)/signal transducer and activator of transcription (STAT) pathway, and to explore the possible mechanism of JAK/STAT pathway. Methods HepG2/ADM cells were cultured in vitro and divided into control group, withaferin A 2.5, 5.0, and 10.0 μmol/L groups. CCK-8 method was used to detect cell proliferation; Hoechst33342 staining was used to observe the morphological changes; Annexin V-FITC/PI double staining was used to detect apoptosis; and Western blotting was used to detect the expressions of apoptosis related protein b-lymphoma-2 (Bcl-2), cleared caspase-3, and phosphorylated JAK2, STAT3 in JAK/STAT pathway. Results The proliferation of HepG2/ADM cells in the withaferin A 2.5, 5.0, and 10.0 μmol/L groups was significantly inhibited in a time and dose-dependent manner (P<0.05). Compared with the control group, some nucleus of HepG2/ADM cells in the withaferin A 2.5, 5.0, and 10.0 μmol/L groups had fragmentation and pyknosis, and the fluorescence intensity increased. Compared with the control group, apoptosis index and apoptosis rate in the withaferin A 2.5, 5.0, and 10.0 μmol/L groups increased significantly (P<0.05), and the expression level of cleaved caspase-3 was significantly increased (P<0.05), but the expressions of Bcl-2, p-JAK2, and p-STAT3 proteins decreased significantly (P<0.05). Conclusions Withaferin A can promote the apoptosis of drug-resistant human hepatoma cells HepG2/ADM cells, and its mechanism may be related to the inhibition of JAK/STAT pathway activation, down-regulation of apoptotic protein expression and up-regulation of apoptotic protein expression.

R966

河南省自然科学基金科技攻关项目（172102310011）