Background Glucose regulated protein 78 （GRP78）, an endoplasmic reticulum （ER） chaperone, plays a critical role in chemotherapy resistance in a variety of cancers. In this study, we investigated the up-regulation of GRP78 induced by A23187 and its association with the chemotherapeutical sensibility to cisplatin in human lung cancer cell line SPCAI. Methods SPCA1 cells were pretreated with A23187 at different concentrations. The expression of GRP78 at the mRNA level was analyzed by RT-PCR; the expression of GRP78 at the protein level was determined by Western blotting and immunofluorescence assay. Cell survival was determined by MTT assay. Cell apoptosis was analyzed by flow cytometry. Results The expression of GRP78 at both the mRNA and protein levels was obviously induced by A23187 in SPCA1 cells, with an elevation of GRP78 by 2.1-fold at the mRNA level and by 3.8-fold at the protein level compared to the control. There was a dose-dependent response. Survival curve analysis demonstrated that A23187 induction caused a significant reduction of survival for the cells subjected to cisplatin treatment （P 〈0.05）. After treatment by cisplatin, the percentage of apoptotic cells in the A23187 pretreated group increased about three fold compared with the control group （（27.53!-4.32）% vs. （9.25＋3.64）%, P 〈0.05）. Conclusions A23187 treatment was fairly effective for the induction of GRP78 in SPCA1 cells at both the mRNA and protein levels. To a certain extent, GRP78 up-regulation by A23187 was associated with the enhancement of drug sensitivity to cisplatin in human luncl cancer cell line SPCAI.
Background：The hedgehog signaling system （HHS） plays an important role in the regulation of cell proliferation and differentiation during the embryonic phases.However,little is known about the involvement of HHS in the malignant transformation of cells.This study aimed to detect the role of HHS in the malignant transformation of human bronchial epithelial （16HBE） cells.Methods：In this study,two microfluidic chips were designed to investigate cigarette smoke extract （CSE）-induced malignant transformation of cells.Chip A contained a concentration gradient generator,while chip B had four cell chambers with a central channel.The 16HBE cells cultured in chip A were used to determine the optimal concentration of CSE for inducing malignant transformation.The 16HBE cells in chip B were cultured with 12.25% CSE （Group A）,12.25% CSE ± 5 μmol/L cyclopamine （Group B）,or normal complete medium as control for 8 months （Group C）,to establish the in vitro lung inflammatory-cancer transformation model.The transformed cells were inoculated into 20 nude mice as cells alone （Group 1） or cells with cyclopamine （Group 2） for tumorigenesis testing.Expression of HHS proteins was detected by Western blot.Data were expressed as mean ± standard deviation.The t-test was used for paired samples,and the difference among groups was analyzed using a one-way analysis of variance.Results：The optimal concentration of CSE was 12.25%.Expression of HHS proteins increased during the process of malignant transformation （Group B vs.Group A,F =7.65,P 〈 0.05）.After CSE exposure for 8 months,there were significant changes in cellular morphology,which allowed the transformed cells to grow into tumors in 40 days after being inoculated into nude mice.Cyclopamine could effectively depress the expression of HHS proteins （Group C vs.Group B,F =6.47,P 〈 0.05） and prevent tumor growth in nude mice （Group 2 vs.Group 1,t=31.59,P〈 0.01）.Conclusions：The activity of HHS is upregulated during the CSE-induced m
Yong-Xin QinZhi-Hui YangXiao-Hui DUHui ZhaoYuan-Bin LiuZhe GuoQi Wang
