Relationship between PTEN expressions and inhibitory effects of Gefitinib on the growth of colon cancer cells

Objective To observe the inhibitory effect of Gefitinib,a selective oral epidermal growth factor receptor tyrosine kinase inhibitor,on the growth of human colon cancer cells,and investigate the relationship between the sensitivity of colon cancer cells to Gefitinib and PIEN expressions.Methods The inhibitory effects of Gefitinib on 6 kinds of colon cancer cells(Lovo,HCT116,HT29,Lsl74T,SW480 and SW620),the levels of PTEN mRNA in different colon cancer cells.and PTEN protein expressions in colon cancer cells were detected by MTT assay,RT-PCR and Westem blot,respectively.Results The inhibitory effects of Gefitinib on the 6 colon cancer cells in vitro varied a lot.When the concentration of Gefitinib was 1 μmol/L,LoVO cells had the most sensitivity to Gefitinib with an IC50＜10μmol/L;HT29 and SW480 had moderate sensitivity,and the IC50 ranged from 10 μnol/L to 100 μmol/L;HCT116,LS174T and SW620 were insensitive to Gefitinib,and their IC50＞100 μmol/L.All the colon cancer cell lines exhibited PTEN mRNA and protein expressions.Conclusions PTEN mRNA andprotein expressions might not be associated with the inhibitory effects of Gefitinib on the growth of colon cancer cells.The expression of PTEN can not be taken as the indication of the sensitivity of colon cancer cells to Gefitinib. Key words: Colon cancer; Cell line;  PTEN;  Gefitinib;  Growth inhibition