title: [Drug resistance mechanism of non small cell lung cancer PC9/AB2 cell line with acquired drug resistance to gefitinib].
abstract: OBJECTIVE
  To study the drug resistance mechanism of non-small cell lung cancer (NSCLC) cell line PC9/AB2 with acquired drug resistance to gefitinib.
  
  
  METHODS
  The human lung adenocarcinoma cell line PC9 was cultured in vitro, and was induced by MNNG to obtain the cell line PC9/AB2 with acquired drug resistance to gefitinib. The sensitivity of the cell line PC9 and PC9/AB2 to gefitinib was determined by MTT assay. The effects of gefitinib on cell apoptosis of the 2 cell lines were determined by flow cytometry. The genomic DNA of the 2 cell lines were extracted, and then the exons 19-21 of EGFR gene were amplified by PCR and sequenced. The protein expression of c-MET and integrin beta1 in the 2 cell lines was determined by Western blot method. The adhesion ability and migration ability of the 2 cell lines were determined by adhesion test and scratch assay.
  
  
  RESULTS
  (1) The data form MTT and apoptosis detection showed that the IC50 of PC9/AB2 cells was (24.2+/-5.5) micromol/L, 576 times higher than PC9 cells [IC50 (0.04+/-0.01) micromol/L]. Given the same concentration of gefitinib, the apoptosis rate of PC9 cells was 38.48%, while that of PC9/AB2 cells was 2.2%. (2) The results of gene sequencing showed that there was a deletion of 15 bp in both exon 19 of the 2 cell lines, while no T790M mutation occurred. (3) The results from Western blot showed that there was no significant difference in protein expression of c-MET between the 2 cell lines, while the protein expression of integrin beta1 in PC9/AB2 cells was significantly higher than that of the PC9 cells. (4) The result from adhesion test and scratch assay showed that the adhesion ability and migration ability of the PC9/AB2 cells was significantly higher that those of PC9 cells.
  
  
  CONCLUSIONS
  The high expression of integrin beta1 may be associated with acquired drug resistance of NSCLC cell line PC9/AB2 to gefitinib.
authors.affiliation: Department of Oncology, Shanghai Pulmonary Hospital, Tongji University, Shanghai 200433, China.
authors.forename: Li-xia
authors.initials: LX
authors.lastname: Ju
authors.forename: Cai-cun
authors.initials: CC
authors.lastname: Zhou
authors.forename: Liang
authors.initials: L
authors.lastname: Tang
authors.forename: Yin-min
authors.initials: YM
authors.lastname: Zhao
authors.forename: Xiao-jun
authors.initials: XJ
authors.lastname: Yang
authors.forename: Bo
authors.initials: B
authors.lastname: Su
authors.forename: Shu-yan
authors.initials: SY
authors.lastname: Meng
authors.forename: Wei
authors.initials: W
authors.lastname: Li
authors.forename: Ling-hua
authors.initials: LH
authors.lastname: Yan
authors.forename: Yong-mei
authors.initials: YM
authors.lastname: Ding
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D002289:Carcinoma, Non-Small-Cell Lung / Q000378:metabolism*; D045744:Cell Line, Tumor / Q000187:drug effects; D019008:Drug Resistance, Neoplasm / Q000187:drug effects*; D000077156:Gefitinib; D006801:Humans; D019012:Integrin beta1 / Q000378:metabolism; D008175:Lung Neoplasms / Q000378:metabolism*; D011799:Quinazolines / Q000494:pharmacology*
chemical_list: D000970:Antineoplastic Agents; D019012:Integrin beta1; D011799:Quinazolines; D000077156:Gefitinib