BACKGROUND: To explore cell lines' difference of drug-resistance to gefitinib and the underlying mechanism. METHODS: Human lung cancer cell lines of PC9, PC9/AB2, PC9/AB11, PC9/BB4 were treated in vitro, exons 18-21 of EGFR gene were sequenced and EGFR gene mRNA levels were measured. RESULTS: Four cell lines' drug resistance difference of gefitinib were validated. All the four cell lines had the 15 bp deletion at exon 19, and AB11 had A to G point-mutation at exon 20. PC9 EGFR gene in the sensitive cell line was expressed much higher than that in 3 resistance cell lines by real-time PCR. CONCLUSIONS: There is significant difference of drug-resistance to gefitinib existed among the lung cancer cell lines PC9, PC9/AB2, PC9/AB11 and PC9/BB4. The mutations changes of expressive level of EGFR gene might be correlated with the acquired drug-resistance to gefitinib in lung cancer cell lines.
BACKGROUND: To explore cell lines' difference of drug-resistance to gefitinib and the underlying mechanism. METHODS:Humanlung cancer cell lines of PC9, PC9/AB2, PC9/AB11, PC9/BB4 were treated in vitro, exons 18-21 of EGFR gene were sequenced and EGFR gene mRNA levels were measured. RESULTS: Four cell lines' drug resistance difference of gefitinib were validated. All the four cell lines had the 15 bp deletion at exon 19, and AB11 had A to G point-mutation at exon 20. PC9EGFR gene in the sensitive cell line was expressed much higher than that in 3 resistance cell lines by real-time PCR. CONCLUSIONS: There is significant difference of drug-resistance to gefitinib existed among the lung cancer cell lines PC9, PC9/AB2, PC9/AB11 and PC9/BB4. The mutations changes of expressive level of EGFR gene might be correlated with the acquired drug-resistance to gefitinib in lung cancer cell lines.