TY - JOUR
T1 - Tumor-associated down-regulation of 15-lipoxygenase-1 is reversed by celecoxib in colorectal cancer
AU - Heslin, Martin J.
AU - Hawkins, Ashley
AU - Boedefeld, William
AU - Arnoletti, J. Pablo
AU - Frolov, Andrey
AU - Soong, Richie
AU - Urist, Marshall M.
AU - Bland, Kirby I.
AU - Merchant, Nipun
AU - Chung, Dai H.
AU - Townsend, Courtney M.
N1 - Copyright:
Copyright 2008 Elsevier B.V., All rights reserved.
PY - 2005/6
Y1 - 2005/6
N2 - Objective: To evaluate the role of celecoxib on 15-lipoxygenase-1 (15-LOX-1) expression, protein levels, and rates of apoptosis in colorectal cancer cell lines. Also, to evaluate the expression of 15-LOX-1 in human normal mucosa, adenoma, and carcinoma with correlation to overall survival. Summary Background Data: The function of 15-LOX-1 is to maintain normal rates of apoptosis (programmed cell death). Decreased apoptosis is one mechanism of cancer growth and dissemination. It is our hypothesis that expression of 15-LOX-1 is reduced in human colorectal cancer (CRC) and the administration of celecoxib can reverse this process and induce apoptosis. Methods: Effect of celecoxib in cell culture: The effect of 40 μmol/L celecoxib was compared with untreated controls in tissue culture utilizing HT-29 and DLD-1 CRC cell lines. Expression of 15-LOX-1 protein was measured by immunoblot. Induction of apoptosis was evaluated by annexin V staining. All data are presented as mean ± SEM, with significance defined as P < 0.05. 15-LOX-1 in human CRC: From February 1998 to January 2002, 126 patients underwent surgical resection of either colorectal adenomas (n = 24) or carcinomas (n = 102), or both (n = 25). Tissue was macrodissected, snap frozen, and stored at -80°C. After tissue processing, RNA was extracted and gene expression of 15-LOX-1 was quantified utilizing ABI prism real-time quantitative RT-PCR. Significance evaluated by the Wilcoxon signed rank test. Results: Effect of celecoxib in cell culture: After 72 hours of treatment with celecoxib, immunoblot demonstrated a 1.5- to 2-fold increase in 15-LOX-1 protein expression in HT-29 and DLD-1 cells, respectively. Celecoxib produced greater than a 2-fold increase in the rate of apoptosis compared with control cells in both cell lines (P < 0.05). 15-LOX-1 in human CRC: The mean age of the patients was 62 ± 1 years; 78% were white and 48% were female. The mean size of the polyps and cancers were 3.0 ± 0.4 and 5.0 ± 0.1 cm, respectively. Expression of 15-LOX-1 relative to S9 was 30 in normal mucosa and significantly down-regulated to 11 in adenomas and 16 in carcinomas (P < 0.05). Conclusions: 15-LOX-1 gene expression is significantly reduced in both human colorectal adenomas and carcinomas and associated with decreased survival. Administration of celecoxib restores 15-LOX-1 protein expression and induces apoptosis. Down-regulation of 15-LOX-1 is an early event in the adenoma to carcinoma sequence, and reversal with celecoxib may represent one mechanism for chemoprevention of polyps or treatment of carcinomas.
AB - Objective: To evaluate the role of celecoxib on 15-lipoxygenase-1 (15-LOX-1) expression, protein levels, and rates of apoptosis in colorectal cancer cell lines. Also, to evaluate the expression of 15-LOX-1 in human normal mucosa, adenoma, and carcinoma with correlation to overall survival. Summary Background Data: The function of 15-LOX-1 is to maintain normal rates of apoptosis (programmed cell death). Decreased apoptosis is one mechanism of cancer growth and dissemination. It is our hypothesis that expression of 15-LOX-1 is reduced in human colorectal cancer (CRC) and the administration of celecoxib can reverse this process and induce apoptosis. Methods: Effect of celecoxib in cell culture: The effect of 40 μmol/L celecoxib was compared with untreated controls in tissue culture utilizing HT-29 and DLD-1 CRC cell lines. Expression of 15-LOX-1 protein was measured by immunoblot. Induction of apoptosis was evaluated by annexin V staining. All data are presented as mean ± SEM, with significance defined as P < 0.05. 15-LOX-1 in human CRC: From February 1998 to January 2002, 126 patients underwent surgical resection of either colorectal adenomas (n = 24) or carcinomas (n = 102), or both (n = 25). Tissue was macrodissected, snap frozen, and stored at -80°C. After tissue processing, RNA was extracted and gene expression of 15-LOX-1 was quantified utilizing ABI prism real-time quantitative RT-PCR. Significance evaluated by the Wilcoxon signed rank test. Results: Effect of celecoxib in cell culture: After 72 hours of treatment with celecoxib, immunoblot demonstrated a 1.5- to 2-fold increase in 15-LOX-1 protein expression in HT-29 and DLD-1 cells, respectively. Celecoxib produced greater than a 2-fold increase in the rate of apoptosis compared with control cells in both cell lines (P < 0.05). 15-LOX-1 in human CRC: The mean age of the patients was 62 ± 1 years; 78% were white and 48% were female. The mean size of the polyps and cancers were 3.0 ± 0.4 and 5.0 ± 0.1 cm, respectively. Expression of 15-LOX-1 relative to S9 was 30 in normal mucosa and significantly down-regulated to 11 in adenomas and 16 in carcinomas (P < 0.05). Conclusions: 15-LOX-1 gene expression is significantly reduced in both human colorectal adenomas and carcinomas and associated with decreased survival. Administration of celecoxib restores 15-LOX-1 protein expression and induces apoptosis. Down-regulation of 15-LOX-1 is an early event in the adenoma to carcinoma sequence, and reversal with celecoxib may represent one mechanism for chemoprevention of polyps or treatment of carcinomas.
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U2 - 10.1097/01.sla.0000164177.95620.c1
DO - 10.1097/01.sla.0000164177.95620.c1
M3 - Article
C2 - 15912043
AN - SCOPUS:21144442338
SN - 0003-4932
VL - 241
SP - 941
EP - 947
JO - Annals of surgery
JF - Annals of surgery
IS - 6
ER -