ABSTRACT

Nav1.7/SCN9A is a voltage gated sodium ion channel (VGSC), expressed by nociceptive neurons. Its role in pain mechanism was well- established but its involvement in the carcinogenic pathways is still under investigation. We aimed to explore the expression of Nav1.7/ SCN9A receptors in intracranial meningiomas and compare it with urothelial, prostate, and ovarian cancers.

Methods: Ten paraffin embedded tissue samples of brain meningioma and 5 cases each of bladder, prostate and ovarian carcinomas were utilized. Immunohistochemistry (IHC) was performed using anti-SCN9A antibody. Cases were scored based on the intensity of expression and number of positive tumour cells. A score of (+3) indicated highest intensity, (+2) as moderate and (+1) as weak intensity. Similarly, 50-100% expression in cells was labelled as (+3), moderate, 30-50% as (+2) and 10-20% as weak or (+1) expression, and (0) as negative.

Results: Nine cases of meningioma were in grade I and single case was grade III. The nine grade I meningioma were negative for SCN9/Nav1.7 expression while the single grade III case was positive. Tumour cells in urothelial, prostate, and ovarian carcinomas were all strongly positive for SCN9/Nav1.7, having intensity expression as (+3).

Conclusions: This study suggests an emerging role of Nav1.7/SCN9A receptor expression in urothelial, prostate, and ovarian cancers as well as grade III meningiomas compared to grade I meningioma. This clarifies that Nav1.7/SCN9A has a possible role in carcinogenesis of most body tumours.