Department of Respiratory Medicine, The First Affiliated Hospital of The Third Military Medical University, Shapingba, Chongqing 400038, P.R. China.
Oncol Rep. 2018 Feb;39(2):611-618. doi: 10.3892/or.2017.6109. Epub 2017 Nov 24.
Cisplatin resistance is a major cause of chemotherapeutic failure in lung cancer patients. Unraveling the molecular mechanisms underlying cisplatin (CDDP) resistance is important in lung cancer therapeutics. To explore the role of Src homology phosphotyrosyl phosphatase 2 (SHP2) in the development of cisplatin resistance in lung cancer and the underlying mechanism, we established stable SHP2‑overexpressing H446‑SHP2-OE cells and SHP2‑knockdown H446/CDDP‑SHP2-shRNA cells derived from H446 and H446/CDDP (cisplatin-resistant) parental lung cancer cells. The cell viability and apoptosis of these cells exposed to CDDP were observed to determine the influence of SHP2 on drug resistance. In addition, the expression of SHP2, Ras, Akt1 and survivin was assessed by western blot analysis after the lung cancer cells were challenged by cisplatin or silenced by Ras siRNA. As a result, the 50% inhibitory concentration (IC50) of the H446-SHP2-OE cells exposed to CDDP increased from 1.01 to 1.218 µg/ml vs. the H446-control vector cells. The percentage of apoptotic cells was smaller in the H446-SHP2-OE cells vs. the H446-control vector cells after cisplatin challenge. In addition, the expression of Ras, pAkt1, Akt1 and survivin in the H446/CDDP cells was significantly increased vs. the H446 cells. Furthermore, the IC50 of the H446/CDDP‑SHP2‑shRNA cells exposed to CDDP decreased from 11.92 to 4.382 µg/ml vs. the H446/CDDP‑mock cells. There were significantly more apoptotic cells among the H446/CDDP‑SHP2-shRNA cells vs. the H446/CDDP-mock cells exposed to cisplatin. A smaller percentage of the H446/CDDP-SHP2-shRNA cells vs. the H446/CDDP‑mock cells was observed. In addition, the expression of pAkt1 and survivin in the H446, H446/CDDP and H446/CDDP-mock cells was increased upon exposure to cisplatin however, a corresponding change was not observed in the H446/CDDP-SHP2-shRNA cells. Upon Ras RNA silencing with cisplatin, the Ras expression was significantly decreased in the H446, H446-SHP2-OE and H446/CDDP cells. However, upon Ras RNA interference, the SHP2 expression was not significantly changed, but the expression of Akt1, pAkt1 and survivin was significantly increased in the H446-SHP2-OE and H446/CDDP cells. In conclusion, SHP2 is a new cisplatin resistance-related phosphatase in lung cancer, which inhibits apoptosis by activating the Ras/PI3K/Akt1/survivin signaling pathway.
顺铂耐药是肺癌患者化疗失败的主要原因。阐明顺铂（CDDP）耐药相关的分子机制对于肺癌治疗具有重要意义。为了探讨Src 同源磷酸酪氨酸磷酸酶 2（SHP2）在肺癌中顺铂耐药发展中的作用及其潜在机制，我们建立了稳定过表达 SHP2 的 H446-SHP2-OE 细胞和 SHP2 敲低的 H446/CDDP-SHP2-shRNA 细胞，这些细胞来源于 H446 和 H446/CDDP（顺铂耐药）亲本肺癌细胞。观察这些细胞在顺铂作用下的细胞活力和凋亡，以确定 SHP2 对耐药性的影响。此外，用顺铂处理或用 Ras siRNA 沉默后，通过 Western blot 分析评估 SHP2、Ras、Akt1 和 survivin 的表达。结果显示，与 H446 对照载体细胞相比，暴露于 CDDP 的 H446-SHP2-OE 细胞的 50%抑制浓度（IC50）从 1.01 增加到 1.218µg/ml。与 H446 对照载体细胞相比，经顺铂处理后 H446-SHP2-OE 细胞中凋亡细胞的比例较小。此外，与 H446 细胞相比，H446/CDDP 细胞中 Ras、pAkt1、Akt1 和 survivin 的表达显著增加。此外，与 H446/CDDP-mock 细胞相比，暴露于 CDDP 的 H446/CDDP-SHP2-shRNA 细胞的 IC50 从 11.92 降低到 4.382µg/ml。与 H446/CDDP-mock 细胞相比，暴露于顺铂的 H446/CDDP-SHP2-shRNA 细胞中凋亡细胞的比例显著增加。与 H446/CDDP-mock 细胞相比，H446/CDDP-SHP2-shRNA 细胞的比例显著减少。此外，与 H446 细胞相比，H446、H446/CDDP 和 H446/CDDP-mock 细胞在暴露于顺铂后 pAkt1 和 survivin 的表达增加，但在 H446/CDDP-SHP2-shRNA 细胞中未观察到相应的变化。用顺铂沉默 Ras RNA 后，H446、H446-SHP2-OE 和 H446/CDDP 细胞中 Ras 表达明显降低。然而，在 Ras RNA 干扰后，SHP2 的表达没有明显变化，但在 H446-SHP2-OE 和 H446/CDDP 细胞中 Akt1、pAkt1 和 survivin 的表达明显增加。总之，SHP2 是肺癌中一种新的顺铂耐药相关磷酸酶，通过激活 Ras/PI3K/Akt1/survivin 信号通路抑制细胞凋亡。
