Abstract:Objective To explore the effect of epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) and chemotherapeutic drug alone, concurrent and sequential administration on apoptosis of non-small cell lung cancer (NSCLC) cells with acquired TKI-resistance. Methods NSCLC cell lines with TKI-resistance gene mutations (T790M and cMET) such as PC9ER, H1975 and HCC827GR as well as TKI-sensitive gene mutation (exon 19) cell lines PC9 and HCC827 were selected. Cell viability was detected by MTS assay when chemotherapy drugs Cisplatin, Paclitaxel and TKI Erlotinib were used alone, in combination or in sequential administration for intervention of NSCLC cell lines, and verified using colony formation assay. The content of apoptosis marker cPARP in cell lysate was detected in each treatment group by Western blot. Results MTS assay and colony formation revealed that the combination of EGFR-TKIs and chemotherapeutic drugs could synergistically increase the cytotoxicity to NSCLC cell lines. Simultaneous use of EGFR-TKIs and chemotherapeutic drugs or chemotherapy followed by EGFR-TKIs provided the maximum intervention. Western blot showed that the apoptotic marker cPARP expression was significantly increased when two drugs were simultaneously used. Moreover, chemotherapy then EGFR-TKIs intervention could obtain a more powerful pro-apoptotic performance than the reverse order intervention. Conclusions The sequence of chemotherapy followed by EGFR-TKI is likely to be the most active strategy, and could have the greatest effect on apoptosis in cell lines with acquired TKI-resistance.