RT Journal Article SR Electronic T1 Down-regulation of P-Glycoprotein Is Associated with Resistance to Cisplatin and VP-16 in Human Lung Cancer Cell Lines JF Anticancer Research JO Anticancer Res FD International Institute of Anticancer Research SP 3593 OP 3598 VO 30 IS 9 A1 JIARUI WANG A1 HUILING WANG A1 LONG ZHAO A1 SUFANG FAN A1 ZHONGHAI YANG A1 FEI GAO A1 LIXIA CHEN A1 GARY GUISHAN XIAO A1 JOSEPH MOLNÁR A1 QI WANG YR 2010 UL http://ar.iiarjournals.org/content/30/9/3593.abstract AB Aim: To investigate whether down-regulation of P-glycoprotein (P-gp) is correlated to resistance to cisplatin and VP-16 in four histopathological subtype cell lines of lung cancer (SK-MES-1, SPCA-1, NCI-H-460 and NCI-H-446). Materials and Methods: After pretreatment with or without verapamil, the P-gp expression was examined by means of RT-PCR and immunofluorescence. Cell survival on treatment with cisplatin and VP-16 was determined by MTT assay. Results: The expression of P-gp was clearly inhibited by verapamil in all four cell lines. Following pretreatment with verapamil, NCI-H-446 was more sensitive to cisplatin, while SPCA-1, NCI-H-460 and NCI-H-446 were more sensitive to VP-16 compared to the control. Conclusion: Down-regulation of P-gp is associated with intrinsic resistance to cisplatin in the NCI-H-446 and to VP-16 in SPCA-1, NCI-H-460 and NCI-H-446 cell lines. These findings indicate that down-regulation of P-gp may be helpful for the reversion of drug resistance in some lung cancer cell line subtypes.