Knockdown of the Bcl-2 gene increases sensitivity to EGFR tyrosine kinase inhibitors in the H1975 lung cancer cell line harboring T790M mutation

  • Authors:
    • Man Zou
    • Shu Xia
    • Liang Zhuang
    • Na Han
    • Qian Chu
    • Tengfei Chao
    • Ping Peng
    • Yu Chen
    • Qi Gui
    • Shiying Yu
  • View Affiliations

  • Published online on: April 12, 2013     https://doi.org/10.3892/ijo.2013.1895
  • Pages: 2094-2102
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Abstract

Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) are being widely used as targeted therapy in non-small cell lung cancer (NSCLC), but most cases acquire drug-resistance in 9 months. However, the mechanisms of resistance are still not fully understood. Since it has been demonstrated that EGFR-TKI-mediated repression of downstream signaling cascades and apoptosis induction is a key mechanism through which EGFR-TKIs exert their cytotoxic effects, we reasoned that activation of downstream signaling pathways and changes in the expression of apoptosis-related proteins contribute to the acquired resistance to EGFR-TKIs. We analyzed the protein levels of p-Akt, Bcl-2, Bax between gefitinib-sensitive and gefitinib-resistant lung cancer cell lines and evaluated whether targeting the anti-apoptotic protein Bcl-2 induces cell apoptosis and further sensitizes resistant H1975 cells to gefitinib. The data showed that p-Akt was activated and accompanied by substantial Bcl-2 in the H1975 lung cancer cell line, whereas no evidence was observed in HCC827 cells. Using small interfering RNA (siRNA) to silence Bcl-2 in H1975 cells led to significant downregulation of Bcl-2 protein expression, decreased cell viability in vitro and induced intrinsic apoptosis confirmed by flow cytometry and PARP cleavage. In Bcl-2 siRNA-transfected cells, adding gefitinib further reduced the number of viable cells, induced apoptosis to a greater extent compared to either treatment alone. These preclinical data suggested that downregulation of Bcl-2 by RNAi in the gefitinib-resistant H1975 lung cancer cell line with T790M mutation enhanced the effects of gefitinib and may offer a novel therapeutic strategy for the treatment of NSCLC.
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June 2013
Volume 42 Issue 6

Print ISSN: 1019-6439
Online ISSN:1791-2423

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Spandidos Publications style
Zou M, Xia S, Zhuang L, Han N, Chu Q, Chao T, Peng P, Chen Y, Gui Q, Yu S, Yu S, et al: Knockdown of the Bcl-2 gene increases sensitivity to EGFR tyrosine kinase inhibitors in the H1975 lung cancer cell line harboring T790M mutation. Int J Oncol 42: 2094-2102, 2013
APA
Zou, M., Xia, S., Zhuang, L., Han, N., Chu, Q., Chao, T. ... Yu, S. (2013). Knockdown of the Bcl-2 gene increases sensitivity to EGFR tyrosine kinase inhibitors in the H1975 lung cancer cell line harboring T790M mutation. International Journal of Oncology, 42, 2094-2102. https://doi.org/10.3892/ijo.2013.1895
MLA
Zou, M., Xia, S., Zhuang, L., Han, N., Chu, Q., Chao, T., Peng, P., Chen, Y., Gui, Q., Yu, S."Knockdown of the Bcl-2 gene increases sensitivity to EGFR tyrosine kinase inhibitors in the H1975 lung cancer cell line harboring T790M mutation". International Journal of Oncology 42.6 (2013): 2094-2102.
Chicago
Zou, M., Xia, S., Zhuang, L., Han, N., Chu, Q., Chao, T., Peng, P., Chen, Y., Gui, Q., Yu, S."Knockdown of the Bcl-2 gene increases sensitivity to EGFR tyrosine kinase inhibitors in the H1975 lung cancer cell line harboring T790M mutation". International Journal of Oncology 42, no. 6 (2013): 2094-2102. https://doi.org/10.3892/ijo.2013.1895