Inhibin-betaA and -betaB subunits in normal and malignant glandular epithelium of uterine cervix and HeLa cervical cancer cell line

Abstract

Inhibins, dimeric peptide hormones composed of an alpha-subunit and one of two possible beta-subunits (betaA or betaB), exhibit substantial roles in human reproduction and in endocrine-responsive tumors. However, it is still unclear if normal and cancerous cervical glandular epithelial cells as well as cervical cancer cell lines of glandular origin express the inhibin-betaA and -betaB subunits. Normal cervical tissue samples and a total of 10 specimens of well-differentiated adenocarcinomas of the human cervix were analyzed for inhibin-betaA and -betaB subunit expression by immunohistochemical analysis. Additionally, the cervical carcinoma cell line HeLa was analyzed by immunofluorescence and RT-PCR analysis for the expression of inhibin subunits. Immunolabeling of normal and malignant glandular epithelium of human cervical tissue revealed a positive staining reaction for the inhibin-betaA and -betaB subunits. Additionally, the cancer cell line HeLa synthesized both inhibin subunits. When compared to the normal cervical glandular epithelium, the expression of the inhibin beta subunits became significantly reduced in cervical adenocarcinoma tissues. In conclusion, we demonstrated a strong, though differential expression pattern of inhibin-betaA and -betaB subunits in normal and malignant glandular epithelial cells of the human uterine cervix. Although the physiological role of inhibins is still quite unclear in cervical tissue, the expression of inhibin-beta-subunits might play an important role in cervical cancer carcinogenesis, since they are significantly down-regulated during pathogenesis in cervical adenocarcinomas.