ER-beta expression in large bowel adenomas: implications in colon carcinogenesis.
BACKGROUND
A pivotal role of oestrogen receptor-beta has been suggested in colon carcinogenesis in humans. However, few data are available on oestrogen receptor-beta in colorectal pre-cancerous lesions.


OBJECTIVE
In the present study, we evaluated oestrogen receptor-beta expression and its possible correlation with proliferative activity and apoptosis in colorectal adenomas and normal colon tissue.


METHODS
Adenomatous tissue from 25 patients with colonic polyps, and normal tissue from 25 controls were used. Oestrogen receptor-beta expression, colonocyte proliferation (expressed as PCNA positivity) and apoptosis were evaluated.


RESULTS
In adenomatous tissue, a significant reduction of oestrogen receptor-beta was observed compared to normal mucosa (10.1+/-5.5% vs. 44.2+/-13.7; p<0.03), while the expression of oestrogen receptor-alpha remained unvaried. Cell proliferative activity significantly increased in adenomatous tissue compared to normal mucosa (59.3+/-7.1 vs. 18.5+/-8.8; p<0.0001), doubling the PCNA/apoptosis ratio. An inverse correlation was found between oestrogen receptor-beta and PCNA expression in adenomas (r=-0.81), a datum confirmed by confocal microscopy evaluation.


CONCLUSIONS
Our data demonstrate, for the first time, a significant reduction of oestrogen receptor-beta expression already in the pre-cancerous phase of colon carcinogenesis. This suggests a role of selective oestrogen receptor-beta agonists in the prevention of colorectal cancer.
Di Leo
A
A
Section of Gastroenterology, Department of Emergency and Organ Transplantation (D.E.T.O.), Bari, Italy. a.dileo@gastro.uniba.it
Barone
M
M
Maiorano
E
E
Tanzi
S
S
Piscitelli
D
D
Marangi
S
S
Lofano
K
K
Ierardi
E
E
Principi
M
M
Francavilla
A
A
D000236:Adenoma / Q000378:metabolism*; D000368:Aged; D017209:Apoptosis / Q000502:physiology; D047629:Estrogen Receptor beta / Q000378:metabolism*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007413:Intestinal Mucosa / Q000378:metabolism; D007414:Intestinal Neoplasms / Q000378:metabolism*; D008297:Male; D008875:Middle Aged
D047629:Estrogen Receptor beta