| Objectives: To investigate the relationship between the expression of GRP78 and resistance to anti-cancer drug VP-16 in vitro in lung adenocarcinoma SPCA1 cell line.Methods: BAPTA-AM and A23187 were used to inhibit or induce the expression of GRP78. RT-PCR was used to detect the expression of GRP78 at gene level and immuno￡luorescence at protein level after cells treated by chemicals at different concentrations. Cell viability was detected by flow cytometry after cells exposed to VP-16 .Results: The expression of GRP78 at both mRNA and protein levels decreased obviously in SPCA1 cell line inhibited by BAPTA-AM, and this inhibition showed dose-dependent to BAPTA-AM to a great degree. The flourescence intensity by BAPTA-AM inhibited group was weaker than by A23187 induced group and the control group obviously. A23187 induced the expression of GRP78 at gene and protein level. As for cell viability, the percentage of apoptotic cells was higher in cells of BAPTA-AM inhibited group at 30μM, lower in cells of A23187 induced group at 2μM.Conclusions: BAPTA-AM is highly effective in the inhibition of GRP78 and subsequent development of resistance to VP-16 in human lung cancer SPCA1 cell line. Based on the trend of the changes of cell viability and the level of GRP78 in different disposed cells, we conclude that BAPTA-AM could inhibit the expression of GRP78 in SPCA1 cell line, and may eliminate the protective effect of GRP78 to tumor cells. It suggests that to interfere with the expression of GRP78 by chemicals such as BAPTA-AM or anti-sense RNA may be a new therapeutic approach to lung cancer.
|
PDF Full Text Request