Liu Lei, Xu Hong, Shi Yue, Cui Jie, Wu Jinxia, Li Shibao
Department of Physiology, Xuzhou Medical University, No. 209 Tongshan Road, Xuzhou, Jiangsu, 221004, China.
Emergency Center, Xuzhou Tongshan District People's Hospital, No. 267 Huaihai West Road, Xuzhou, Jiangsu, 221006, China.
Heliyon. 2023 Mar 2;9(3):e14169. doi: 10.1016/j.heliyon.2023.e14169. eCollection 2023 Mar.
The use of γ-secretase inhibitors to inhibit the activation of Notch receptors can effectively inhibit the malignant process of tumors. Here, we demonstrate that p53 can modulate the effect of DAPT (a γ-secretase inhibitor) on the activation of small GTPase Rac1, thereby affecting cell migration of non-small-cell lung cancer H1299 and A549 cells. After treatment with 20 μM DAPT, activation of Rac1 was increased in H1299 cells but not in A549 cells. We further found that the migration ability of H1299 cells was increased, whereas that of A549 cells was reduced. The effect of DAPT on H1299 migration was repressed by Rac1-T17N, a dominant inactivated mutant of Rac1. H1299 is a p53-deficient cell line. When p53 protein was overexpressed in H1299 cells with a pEGFP-p53 plasmid, DAPT treatment no longer activated Rac1 and increased migration ability. Moreover, DAPT promoted the migration of H1299 cells by increasing the activity of Rac1 through the non-canonical Notch pathway. Taken together, these results indicate that the expression of p53 protein in lung cancer cells regulates the effect of DAPT on cell migration by modulating the activation of Rac1, suggesting that p53 may affect the therapeutic effects of Notch inhibitors in lung cancer patients.
使用γ-分泌酶抑制剂抑制Notch受体的激活可有效抑制肿瘤的恶性进程。在此，我们证明p53可调节DAPT（一种γ-分泌酶抑制剂）对小GTP酶Rac1激活的影响，从而影响非小细胞肺癌H1299和A549细胞的迁移。用20μM DAPT处理后，H1299细胞中Rac1的激活增加，而A549细胞中未增加。我们进一步发现H1299细胞的迁移能力增强，而A549细胞的迁移能力降低。Rac1的显性失活突变体Rac1-T17N可抑制DAPT对H1299迁移的影响。H1299是一种p53缺陷细胞系。当用pEGFP-p53质粒在H1299细胞中过表达p53蛋白时，DAPT处理不再激活Rac1，也不再增加迁移能力。此外，DAPT通过非经典Notch途径增加Rac1的活性来促进H1299细胞的迁移。综上所述，这些结果表明肺癌细胞中p53蛋白的表达通过调节Rac1的激活来调节DAPT对细胞迁移的影响，提示p53可能影响Notch抑制剂对肺癌患者的治疗效果。
