Application of microfluidic gradient chip in the analysis of lung cancer chemotherapy resistance

The major challenge of chemotherapy is the disease resistance for many lung cancer patients. Integrated microfluidic systems offer many desirable characteristics and can be used in cellular biological analysis. This work aimed to study the correlation between the expression of Glucose Regulated Protein-78 (GRP78) and the resistance to anticancer drug VP-16 in human lung squamous carcinoma cell line SK-MES-1 using an integrated microfluidic gradient chip device. We used A23187, a GRP78 inducer, with a gradient concentration in the upstream network of the device to induce the expression of GRP78 in the cells cultured in the downstream before the addition of VP-16. The expression of GRP78 was detected by immunofluorescence, the apoptosis for the cells treated by VP-16 was assessed morphologically by 4',6-diamidino-2-phenylindole (DAPI) staining. The results indicated that the expressions of GRP78 increased greatly for the cells under the induction of A23187 with a dose-depended manner, while the percentage of apoptotic cells decreased significantly after being treated by VP-16. Our results from this study confirmed the role of GRP78 played in the chemotherapy resistance to VP-16 in SK-MES-1 cell line, suggesting that the integrated microfluidic systems may be an unique approach for characterizing the cellular responses. (C) 2008 Elsevier B.V. All rights reserved.