Estrogen in obesity-associated colon cancer: friend or foe? Protecting postmenopausal women but promoting late-stage colon cancer

Chen, Jiezhong and Iverson, Don (2012) Estrogen in obesity-associated colon cancer: friend or foe? Protecting postmenopausal women but promoting late-stage colon cancer. Cancer Causes and Control, 23 11: 1767-1773. doi:10.1007/s10552-012-0066-z


Author Chen, Jiezhong
Iverson, Don
Title Estrogen in obesity-associated colon cancer: friend or foe? Protecting postmenopausal women but promoting late-stage colon cancer
Journal name Cancer Causes and Control   Check publisher's open access policy
ISSN 1573-7225
0957-5243
Publication date 2012-11-01
Year available 2012
Sub-type Critical review of research, literature review, critical commentary
DOI 10.1007/s10552-012-0066-z
Volume 23
Issue 11
Start page 1767
End page 1773
Total pages 7
Place of publication Dordrecht, Netherlands
Publisher Springer
Collection year 2013
Language eng
Abstract Obesity is associated with the increased incidence of colon cancer. Many cancer risk factors have been identified including increased blood levels of insulin, leptin, interleukin-6, interleukin-17, tumor necrosis factor-alpha, and decreased blood levels of adiponectin. However, the role of blood levels of estrogen in obesity-associated colon cancer is controversial. Evidence showed that obesity affected men more strongly than women in the carcinogenesis of colon cancer, indicating protective effect of estrogen which is increased in obesity. However, an epidemiological study has also shown that endogenous estradiol level is an independent risk factor for colon cancer, positively associated with colon cancer after normalizing insulin, IGF-1. The controversial opinions may be caused by different effects of ER-alpha and ER-beta. ER-alpha can increase colon cancer cell proliferation and increase cancer incidence. ER-beta has the opposite effect to ER-alpha, and it causes apoptosis of colon cancer cells. The normal colonocytes mainly express ER-beta. Therefore, increased estrogen in obesity may have protective effect via ER-beta in obesity-associated colon cancer. However, with the development of colon cancer, ER-alpha is increased and ER-beta is decreased. In the late stage of colon cancer, estrogen may promote cancer development via ER-alpha. The different effects and expression of ER-alpha and ER-beta may explain the different results observed in several epidemiological studies as well as several animal experiments. Therefore, manipulation of estrogen-caused signal pathways to inhibit ER-alpha and stimulate ER-beta may have preventive and therapeutic effect for obesity-associated colon cancer.
Keyword Obesity-associated colon cancer
ER-alpha
ER-beta
Q-Index Code C1
Q-Index Status Provisional Code
Institutional Status Non-UQ

Document type: Journal Article
Sub-type: Critical review of research, literature review, critical commentary
Collection: School of Biomedical Sciences Publications
 
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Created: Thu, 13 Mar 2014, 23:25:21 EST by Jiezhong Chen on behalf of School of Biomedical Sciences