LKB1调控PTEN/PI3K/AKT通路诱导多发性骨髓瘤细胞凋亡

LKB1 regulates the PTEN/PI3K/AKT pathway to induce multiple myeloma cell apoptosis

[目的]探讨LKB1诱导多发性骨髓瘤细胞凋亡的潜在机制。[方法]构建LKB1敲除细胞系,比较敲除和未敲除LKB1的多发性骨髓瘤细胞RPMI 8266和U266的增殖水平、凋亡水平、PTEN/PI3K/AKT通路相关蛋白的表达水平。在RPMI 8266和U266 LKB1敲除细胞系中过表达LKB1野生型(LKB1 WT)或LKB1酶活突变型(LKB1 K78M)后检测凋亡水平。PTEN抑制剂和激活剂、PI3K抑制剂和激活剂、AKT抑制剂和激活剂处理后,检测LKB1敲除多发性骨髓瘤细胞系的凋亡水平。[结果]LKB1敲除后,多发性骨髓瘤细胞RPMI 8266和U266的增殖水平上升(2.67±0.10 vs 3.46±0.08,P<0.05),凋亡水平下降(15.74%±3.17%vs 6.68%±1.34%,P<0.05)。相比于LKB1野生型,LKB1 K78M的增殖水平上升(2.15±0.10 vs 3.51±0.08,P<0.05),凋亡水平下降(36.98%±3.36%vs 6.05%±1.32%,P<0.05)。敲除LKB1后,多发性骨髓瘤细胞RPMI 8266和U266中p-AKT、p-PI3K的表达水平上升,PTEN水平下降,而AKT和PI3K的水平无显著变化。PTEN激活剂、PI3K抑制剂、AKT抑制剂能使处理后RPMI 8266和U266 LKB1敲除细胞的增殖水平和凋亡水平恢复到LKB1未敲除的状态(6.88%±1.42%vs 15.39%±3.21%,P<0.05)。[结论]LKB1通过调控PTEN/PI3K/AKT通路诱导多发性骨髓瘤细胞凋亡。

[Objective]To investigate the potential mechanism of LKBI-induced apoptosis in multiple myeloma cells.[Meth-od] LKBI knockout cell line was constructed,and the proliferation level,apoptosis level and PTEN/PI3K/AKT path-related protein expression level of multiple myeloma cells RPMI 8266 and U266 with and without LKBI knockout were compared.Ap-optosis levels were detected after overexpression of LKBI wild type(LKBI WT)or LKBI active mutant(LKBI K78M)in RPMI 8266 and U266 LKB1 knockout cell lines.After treatment with PTEN inhibitor and activator,PI3K inhibitor and activator,AKT inhibitor and activator,the apoptotic level of multiple myeloma cell lines with LKBI knockout was detected.[Result]After LKBI knockout,the proliferation level of multiple myeloma cells RPMI 8266 and U266 increased(2.67±0.10 us 3.46±0.08,P<0.05),and the apoptosis level decreased(15.74%±3.17%us 6.68%±1.34%,P<0.05).Compared with the LKB1 wild type,the proliferation level of LKB1 K78M increased(2.15±0.10 vs 3.51±0.08,P<0.05),and the apoptosis level de-creased(36.98%±3.36%us 6.05%±1.32%,P<0.05).After LKB1 knockout,the expression level of p-AKT and p-PI3K in multiple myeloma cells RPMI 8266 and U266 increased,while the level of PTEN decreased,while the level of AKT and PI3K did not change significantly.PTEN activator,PI3K inhibitor and AKT inhibitor could restore the proliferation level and ap-optosis level of RPMI 8266 and U266 LKBI knockout cells to the state without LKBI knockout(6.88%±1.42%vs 15.39%±3.21%,P<0.05).[Conclusion]LKBI induces multiple myeloma cell apoptosis by regulating the PTEN/PI3K/AKT pathway.