Subsite-specific differences of estrogen receptor beta expression in the normal colonic epithelium: implications for carcinogenesis and colorectal cancer epidemiology.
OBJECTIVE
This study aimed at investigating whether a differential estrogen receptor beta (ER-beta) expression between the colonic subsites could correspond to a modification in proliferation, apoptosis, and adhesion of the normal colonocytes.


METHODS
ER-beta, Ki-67, Bcl-2, and E-cadherin expressions were investigated immunohistochemically, in normal epithelium biopsies from the ascending and the descending colon of 53 individuals, who underwent colonoscopy for the investigation of anemia and in whom no local pathology was identified.


RESULTS
ER-beta immunoreactivity has been shown to be stronger at the superficial epithelium than the crypts' base, the difference being important only for the ascending colon. In addition, ER-beta expression was higher in the superficial epithelium of the ascending colon than that of the descending colon. The variations of ER-beta expression did not correspond to the alterations in Ki-67, Bcl-2, and E-cadherin expression.


CONCLUSIONS
A subsite-specific variation of ER-beta expression has been shown in the normal colonic epithelium. This modulation of ER-beta might account for some well established specificities of colorectal cancer epidemiology like the right-sided predominance of the neoplasm in women and its gradual shift to more proximal sites over time.
Papaxoinis
Kostis
K
First Department of Propaedeutic Medicine, Laiko University General Hospital, National and Kapodistrian University of Athens, School of Medicine, Athens, Greece. kopap@med.uoa.gr
Triantafyllou
Kostas
K
Sasco
Annie J
AJ
Nicolopoulou-Stamati
Polyxeni
P
Ladas
Spiros D
SD
D000328:Adult; D000368:Aged; D017209:Apoptosis / Q000502:physiology; D001706:Biopsy; D002448:Cell Adhesion / Q000502:physiology; D002455:Cell Division / Q000502:physiology; D044682:Colon, Ascending / Q000378:metabolism* / Q000473:pathology; D044683:Colon, Descending / Q000378:metabolism* / Q000473:pathology; D003113:Colonoscopy; D015179:Colorectal Neoplasms / Q000378:metabolism* / Q000473:pathology; D047629:Estrogen Receptor beta / Q000378:metabolism*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007413:Intestinal Mucosa / Q000378:metabolism* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D012016:Reference Values
D047629:Estrogen Receptor beta