PSII-23 Aflatoxin B1 influences expression of TRPM8 in SKOV, ovarian epithelial cancer cells

Abstract

Abstract Aflatoxins are mold products of Aspergillus flavus. They are common food contaminants that affect dietary staples. Aflatoxins are most prevalent in emerging countries and negatively impact the health and reproduction of several animals. Aflatoxin B1 (AFB1) affects fertility in many species by decreasing the number of gametes. The mechanism for aflatoxin’s effect on gamete production has not been fully elucidated. In aflatoxin treated rats, steroidogenesis is affected by the competitive binding of aflatoxin to the StAR protein. The transient receptor potential melastatin 8 (TRPM8) is a nonselective cation channel highly expressed in male reproductive tracts, and sheep ovaries. TRPM8 binds testosterone and is responsive to steroids. The objective of these experiments is to determine if AFB1 influenced the expression of TRPM8 channels in an ovarian cell line. Human epithelial ovarian cells, SKOV, were seeded into chamber slides and treated in triplicate with media containing ethanol, 5µg/ml AFB1, 10µg/ml AFB1, or 20µg/ml AFB1 for 24 hours. The cells were stained for TRPM8 using immunocytochemistry and in a replicate experiment, analyzed for mRNA using Real Time RT-PCR protocols. Images were captured at 200x magnification and analyzed. Mean gray scale intensity was used to determine staining intensity as a reflection of TRPM8 expression. SKOV cells treated with AFB1 had increased staining (P ≤ 0.001) compared to ethanol treated cells. Relative TRPM8 mRNA did not differ with AFB1 treatments (P = 0.2). Inconsistency between mRNA and protein expression may be due to the timing of mRNA synthesis and translation of the protein. Based on these results, expression of TRPM8 in SKOV cells increased in response to AFB1. Although it is not certain if this effect is restricted to these transformed cells, the possibility remains that changes in TRPM8 expression may contribute to the negative reproductive consequences of AFB1 exposure in humans and livestock species.