The cervical malignant cells display a down regulation of ER-α but retain the ER-β expression.
The human cervix is a tissue target of sex steroid hormones as estradiol (E2) which exerts its action through of the estrogen receptors alpha and beta (ER-α and ER-β). In this study we investigated the expression of ER-α and ER-β in human invasive cervical carcinomas using immunohistochemistry and RT-PCR analyses and compared with that observed in the corresponding normal tissue. The results show nuclear expression of ER-α mainly in the first third of normal cervical epithelium, however, decreased or absent expression were present in invasive cervical carcinoma, indicating that expression of ER-α is lost in cervical cancer. Nevertheless, by RT-PCR we were able to demonstrate mRNA expression of ER-α in invasive cervical tissues. These results suggest that loss of ER-α could be due to a mechanism of post-transcriptional and/or post-translational regulation of its gene during the progression to invasive carcinoma. On the other hand, ER-β was expressed in normal cervix with an expression pattern similar to ER-α. In addition to its nuclear localization, cytoplasmic immunoreaction of ER-β was present in the epithelium of invasive cervical carcinomas, suggesting an association between cytoplasmic ER-β expression and invasive phenotype in the cervical tumors. In summary, the results show that the cervical malignant cells tend to loss the ER-α but maintain the ER-β actively expressed. Loss of expression of ER-α in neoplastic tissue suggests that the estrogenic effects could be conducted through the ER-β in human neoplastic cervical tissue. More detailed studies are needed to confirm this suggestion and to determine the role of ER-β in cervical cancer.
Laboratorio de Oncología Genómica, Unidad de Investigación Médica en Enfermedades Oncológicas, Hospital de Oncología, Centro Médico Nacional Siglo XXI, Instituto Mexicano del Seguro Social, México D.F.
Ricardo
R
López-Romero
Efraín
E
Garrido-Guerrero
Angélica
A
Rangel-López
Leticia
L
Manuel-Apolinar
Patricia
P
Piña-Sánchez
Minerva
M
Lazos-Ochoa
Alejandra
A
Mantilla-Morales
Cindy
C
Bandala
Mauricio
M
Salcedo
D014408:Biomarkers, Tumor / Q000032:analysis / Q000235:genetics; D002294:Carcinoma, Squamous Cell / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D015536:Down-Regulation; D047628:Estrogen Receptor alpha / Q000032:analysis / Q000096:biosynthesis* / Q000235:genetics; D047629:Estrogen Receptor beta / Q000032:analysis / Q000096:biosynthesis* / Q000235:genetics; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D020133:Reverse Transcriptase Polymerase Chain Reaction; D002583:Uterine Cervical Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology
D014408:Biomarkers, Tumor; C506487:ESR1 protein, human; D047628:Estrogen Receptor alpha; D047629:Estrogen Receptor beta
ER-α; ER-β; HPV; cervical cancer