Expression of ERalpha, ERbeta and co-regulator PELP1/MNAR in colorectal cancer: prognostic significance and clinicopathologic correlations.
BACKGROUND
Estrogen receptor beta (ERbeta) is abundantly expressed in colorectal tissue, but its role in colorectal carcinogenesis remains elusive. ER novel co-regulator, proline-, glutamic acid- and leucine-rich protein 1 (PELP1/MNAR) has been characterized, but its expression in colorectal carcinomas has not been investigated.


METHODS
ERalpha, ERbeta and PELP1/MNAR protein expression were evaluated by immunohistochemistry in colorectal normal mucosa, adenomas and adenocarcinomas from 113 patients with colorectal cancer.


RESULTS
ERalpha expression is extremely rare in colorectal tissue and its expression does not appear to be associated with colorectal carcinogenesis. ERbeta and PELP1/MNAR were detected in the nucleus of epithelial, endothelial, inflammatory, smooth muscle cells and myofibroblasts. When intensity of staining was taken into account, the expression of both proteins was significantly increased in epithelial cells of carcinomas compared to normal mucosa. ERbeta expression in epithelial cells was correlated with decreased disease progression - free survival. PELP1/MNAR overexpression in epithelial cells was found to be an independent favorable prognostic factor. Additionally, the expression of both proteins was significantly increased in stromal myofibroblasts of carcinomas compared to adenomas and normal mucosa.


CONCLUSIONS
ERbeta and PELP1/MNAR appear to be involved in colorectal tumorigenesis and might have prognostic significance.
Grivas
Petros D
PD
Division of Oncology and Clinical Oncology Laboratory, Medical School, University of Patras, Patras, Greece. grivas_p@yahoo.gr
Tzelepi
Vassiliki
V
Sotiropoulou-Bonikou
Georgia
G
Kefalopoulou
Zinovia
Z
Papavassiliou
Athanasios G
AG
Kalofonos
Haralabos
H
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002277:Carcinoma / Q000175:diagnosis / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D056970:Co-Repressor Proteins; D015179:Colorectal Neoplasms / Q000175:diagnosis / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D047628:Estrogen Receptor alpha / Q000235:genetics / Q000378:metabolism*; D047629:Estrogen Receptor beta / Q000235:genetics / Q000378:metabolism*; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007413:Intestinal Mucosa / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors
D056970:Co-Repressor Proteins; D047628:Estrogen Receptor alpha; D047629:Estrogen Receptor beta; C438485:PELP1 protein, human; D015534:Trans-Activators; D014157:Transcription Factors