Yu Zhuang, Li Xiu-Mei, Liu Shi-Hai, Liu Bing, Gao Cai-Hong, Hou Xin
Department of Oncology, The Affiliated Hospital of Qingdao University, Qingdao 266003, P.R. China.
Central Laboratory, The Affiliated Hospital of Qingdao University, Qingdao 266003, P.R. China.
Oncol Rep. 2014 Apr;31(4):1818-24. doi: 10.3892/or.2014.3027. Epub 2014 Feb 18.
Epidermal growth factor receptor (EGFR) and ErbB3 (HER3) play important roles in the regulation of cell proliferation, differentiation, anti-apoptosis and chemoresistance; however, their dysregulation in pemetrexed (PEM) resistance remains unclear. The aim of the present study was to clarify the relationship between PEM resistance and gene expression of EGFR and ErbB3, by establishing the PEM-resistant lung adenocarcinoma A549 cell line, A549/PEM. Compared with A549 cells, the A549/PEM cells were significantly more resistant to PEM (P=0.0024). The downregulation of S phase and arrest at G1 stage were detected in the A549/PEM cell line when compared to the A549 cells (P<0.05). The apoptosis rate of A549/PEM cells was much lower than that of the A549 cells after a 24 h continuous exposure to PEM (P<0.001). Real-time PCR and western blotting demonstrated the overexpression of EGFR and ErbB3 in A549/PEM cells. However, downregulation of EGFR or ErbB3 by lentiviral delivered shRNAs in A549/PEM cells showed no significant correlation with PEM sensitivity while silencing both EGFR and ErbB3 increased the cellular response to PEM in the A549/PEM cells and significantly decreased phosphorylation of STAT3, AKT and ERK. Together, these data suggest that either high expression of EGFR or ErbB3 plays a critical role in the cellular response to PEM in human lung adenocarcinoma cells though EGFR/ErbB3-dependent pathways.
表皮生长因子受体（EGFR）和ErbB3（HER3）在细胞增殖、分化、抗凋亡及化疗耐药性调控中发挥重要作用；然而，它们在培美曲塞（PEM）耐药中的失调情况仍不清楚。本研究的目的是通过建立PEM耐药的肺腺癌A549细胞系A549/PEM，阐明PEM耐药与EGFR和ErbB3基因表达之间的关系。与A549细胞相比，A549/PEM细胞对PEM的耐药性显著更高（P = 0.0024）。与A549细胞相比，在A549/PEM细胞系中检测到S期下调并停滞于G1期（P < 0.05）。连续24小时暴露于PEM后，A549/PEM细胞的凋亡率远低于A549细胞（P < 0.001）。实时PCR和蛋白质印迹法显示A549/PEM细胞中EGFR和ErbB3过表达。然而，慢病毒递送的短发夹RNA（shRNAs）在A549/PEM细胞中下调EGFR或ErbB3与PEM敏感性无显著相关性，而同时沉默EGFR和ErbB3可增强A549/PEM细胞对PEM的细胞反应，并显著降低信号转导及转录激活因子3（STAT3）、蛋白激酶B（AKT）和细胞外信号调节激酶（ERK）的磷酸化。总之，这些数据表明，尽管通过EGFR/ErbB3依赖性途径，但EGFR或ErbB3的高表达在人肺腺癌细胞对PEM的细胞反应中起关键作用。
