title: Heat shock protein 27 is associated with irinotecan resistance in human colorectal cancer cells.
abstract: Heat shock protein (Hsp) in tumor cells has been proposed to enhance their resistance to chemotherapeutic agents. In the present study, we investigated the influence of Hsp expression on the irinotecan resistance of human colorectal cancer cells. Among eight Hsp genes tested in this study, we confirmed that the expression of Hsp27 correlated with irinotecan resistance in colorectal cancer cells. Specific inhibition of Hsp27 expression using an antisense oliogodeoxynucleotide increased the irinotecan sensitivity. On the contrary, an overexpression of Hsp27 decreased the irinotecan sensitivity in colorectal cancer cells. Elevated expression of Hsp27 decreased caspase-3 activity in colorectal cancer cells. The expression level of Hsp27 determined by immunohistochemical analysis correlated with the clinical response to irinotecan in colorectal cancer patients. Hsp27 expression levels of irinotecan-non-responder (mean staining score, 6.28; proportion of high staining score, 64.2%) were significantly higher compared to those of irinotecan-responder (mean staining score, 3.16; proportion of high staining score, 33.3%) (P for t-test=0.045). These findings suggest that Hsp27 is involved in the irinotecan resistance of colorectal cancer cells possibly by reducing caspase-3 activity.
authors: Department of Surgery, Ulsan University Hospital, University of Ulsan College of Medicine, Ulsan 682-060, Republic of Korea. dhchoi@uuh.ulsan.kr <dhchoi@uuh.ulsan.kr>
authors: Dae Hwa
authors: DH
authors: Choi
authors: Jin Sook
authors: JS
authors: Ha
authors: Won Hyuck
authors: WH
authors: Lee
authors: Jeong Kee
authors: JK
authors: Song
authors: Gyu Yeol
authors: GY
authors: Kim
authors: Jae Hoo
authors: JH
authors: Park
authors: Hee Jeong
authors: HJ
authors: Cha
authors: Byung Ju
authors: BJ
authors: Lee
authors: Jeong Woo
authors: JW
authors: Park
mesh_terms: D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology*; D017209:Apoptosis / Q000235:genetics; D002166:Camptothecin / Q000031:analogs & derivatives* / Q000494:pharmacology; D053148:Caspase 3 / Q000378:metabolism; D045744:Cell Line, Tumor; D015179:Colorectal Neoplasms / Q000737:chemistry / Q000235:genetics*; D019008:Drug Resistance, Neoplasm / Q000235:genetics*; D006360:Heat-Shock Proteins / Q000032:analysis / Q000235:genetics*; D006801:Humans; D007150:Immunohistochemistry; D000077146:Irinotecan; D015854:Up-Regulation
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D006360:Heat-Shock Proteins; D000077146:Irinotecan; D053148:Caspase 3; D002166:Camptothecin