Comparative proteomic analysis of irinotecan-sensitive colorectal carcinoma cell line and its chemoresistant counterpart

In this study, we used two-dimensional gel electrophoresis and MALDI-Q-TOF-MS/MS analysis to examine the global protein expression of a pair of colorectal carcinoma cell lines, SW620 and irinotecan-resistant SW620. Of the 30 spots identified as differentially expressed proteins (+/- over twofold, P < 0.05) between the two cell lines, 26 spots (corresponding to 26 unique proteins) were positively identified by MALDI-Q-TOF-MS/MS analysis. These proteins could be grouped into main classes including metabolism (15.38%), cell SSproliferation/differentiation (11.53%), molecular chaperone (11.53%), mRNA splicing (11.53%), and so on. The proteins, which might be involved in the development of tumor drug resistance, such as a-enolase, cofilin, and thioredoxin-dependent peroxide 1, have been validated by western blot analysis and have been discussed. The proteins identified in this study may be useful in showing the mechanisms underlying irinotecan resistance. Anti-Cancer Drugs 22:500-506 (C) 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins.