Follicle-stimulating hormone receptors: A comparison of commercially-available monoclonal and polyclonal antibodies as immunohistochemical markers for cancer research.

Purpose: In recent studies, follicle-stimulating hormone receptors (FSHRs) have been reported in a wide range of malignant and benign tumours, depending on the type of antibody used. Using two commercially available antibodies (monoclonal and polyclonal), the current research attempted to demonstrate the usefulness of each antibody for investigating FSHRs in non-canonical tissues. Further, we sought to replicate the results of a major study which demonstrated the presence of FSHRs in the endothelial cells of perineoplastic blood vessels.

Methods: Immunostaining was performed on 16 surgically excised benign and malignant tumor tissue samples using both monoclonal and polyclonal anti-FSHR antibodies.

Results: Positive staining of FSHRs was heterogeneous among the tissue samples used for analysis, and was confirmed not only in tumour and endothelial cells of perineoplastic blood vessels, but also in benign and normal cells. Based on our findings, FSHR staining using a polyclonal antibody appeared to be highly sensitive, but with a relatively low specificity. Comparatively, immunoreactivity using a monoclonal antibody appeared to show high specificity, but relatively low sensitivity. Although the selected monoclonal antibody for FSHRs seemed to be more specific than the polyclonal variant, neither exhibited a high overall specificity. Neither of the antibodies assessed in the present research could replicate the results of the aforementioned major study.

Conclusions: In conclusion, neither of the two commercially available antibodies seem to be appropriate for investigating FSHRs in non-canonical tissues and, by extension, their role in carcinogenesis.