title: [Sensitivity of two cell lines with acquired resistance to gefitinib to several chemotherapeutic drugs].
abstract: OBJECTIVE
  To explore the sensitivity of tumor cell lines with acquired resistance to gefitinib to several chemotherapeutic drugs and provide preclinical basis of available chemotherapy regimens after failure of molecular targeted therapy.
  
  
  METHODS
  Human lung adenocarcinoma cell lines PC9 and PC9/G with acquired resistance to gefitinib were cultured in vitro. The sensitivity to chemotherapeutic drugs and inhibition rate of cell proliferation was determined by MTT assay. Effects of drugs on apoptosis and expression of P-170 were determined by flow cytometry. Difference of gene expression profile between PC9 and PC9/G cells was analyzed by DNA microarray. Western blot was used to test the expression of Akt, phospho-Akt and integrin beta1.
  
  
  RESULTS
  The resistance index of PC9/G cells to cisplatin was about 5.4-fold compared with that of PC9 cells. LY294002 may significantly elevate the sensitivity of PC9/G cells to cisplatin (P < 0.05). PC9/G cells were more sensitive to docetaxel than PC9 cells. No significant difference of sensitivity to pemetrexed was found between these two cell lines. Expression level of P-170 in PC9/G cells was lower than that in PC9 cells. In PC9/G cells, the expression of integrin beta1 and DNA healing gene was high and expression of gene during mitosis was low. The level of expression of Akt, phospho-Akt and integrin beta1 in PC9/G cells was higher than that in PC9 cells.
  
  
  CONCLUSIONS
  In PC9/G cells, a cell line with acquired resistance to gefitinib, over-expression of PI3K, integrin and DNA restoration gene and continuous activation of PI3K is found to be correlated with resistance to cisplatin. Docetaxel or pemetrexed is a more reasonable choice than cisplatin for treatment of NSCLC patients who failed to respond to EGFR-TKI.
authors.affiliation: Department of Oncology, Shanghai Pulmonary Hospital, Tongji University, Shanghai 200433, China.
authors.forename: Qin-fang
authors.initials: QF
authors.lastname: Deng
authors.forename: Bo
authors.initials: B
authors.lastname: Su
authors.forename: Yin-min
authors.initials: YM
authors.lastname: Zhao
authors.forename: Cai-cun
authors.initials: CC
authors.lastname: Zhou
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000378:metabolism; D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D002289:Carcinoma, Non-Small-Cell Lung / Q000378:metabolism / Q000473:pathology*; D045744:Cell Line, Tumor; D002867:Chromones / Q000494:pharmacology; D000077143:Docetaxel; D019008:Drug Resistance, Neoplasm; D000077156:Gefitinib; D005971:Glutamates / Q000494:pharmacology; D006147:Guanine / Q000031:analogs & derivatives / Q000494:pharmacology; D006801:Humans; D019012:Integrin beta1 / Q000378:metabolism; D008175:Lung Neoplasms / Q000378:metabolism / Q000473:pathology*; D009025:Morpholines / Q000494:pharmacology; D000068437:Pemetrexed; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D000081082:Phosphoinositide-3 Kinase Inhibitors; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D011799:Quinazolines / Q000494:pharmacology*; D043823:Taxoids / Q000494:pharmacology
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D000970:Antineoplastic Agents; D002867:Chromones; D000077143:Docetaxel; D000077156:Gefitinib; D005971:Glutamates; D006147:Guanine; D019012:Integrin beta1; D009025:Morpholines; D000068437:Pemetrexed; D019869:Phosphatidylinositol 3-Kinases; D000081082:Phosphoinositide-3 Kinase Inhibitors; D051057:Proto-Oncogene Proteins c-akt; D011799:Quinazolines; D043823:Taxoids; C085911:2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one