In-Vitro Determination of the Differential Roles of Androgens (Androstenedione and Testosterone) and Progesterone in Increased Male Mortality in Melanoma Using a Human Melanoma (BLM) Cell Model

Program: Abstracts - Orals, Poster Previews, and Posters
Session: SUN 203-235-Steroid Hormone Actions, Biosynthesis and Metabolism (posters)
Bench to Bedside
Sunday, April 3, 2016: 1:15 PM-3:15 PM
Exhibit/Poster Hall (BCEC)

Poster Board SUN 233
Travis Hohenbery*1, Kumud Joshi2 and Pandurangan Ramaraj3
1KCOM/A T Still University, Kirksville, MO, 2KCOM, Kirksville, MO, 3KCOM/A.T.Still Univeersity, Kirksville, MO
Epidemiological studies showed that male mortality was high in melanoma, suggesting a sex difference. Clinical studies showed the involvement of sex hormones in protecting menstruating females, but not males in melanoma. Our earlier in-vitro study (1) showed progesterone, a female sex hormone significantly killed human melanoma cells. This observation raised the question whether androgens (DHEA, AD and T) were responsible for increased male mortality in melanoma, as androgens levels were higher in males than in females. Our previous work with mouse melanoma cells showed that androgens [dehydroepiandrosterone (DHEA), androstenedione (AD) and testosterone (T)] also inhibited melanoma cell growth in-vitro. Moreover, addition of progesterone as low as 10 µM concentration to androgens showed significant additive effect on the inhibition of cell growth in-vitro. This observation raised the question whether deficiency of progesterone in males was responsible for increased mortality in males. We decided to answer this question by using a human melanoma (BLM) cell model. Our aims were to study the effect of AD and T on human melanoma cell growth and their mechanism of inhibition of cell growth. In order to determine the effect of deficiency of progesterone on cell growth, we decided to supplement progesterone at an increasing concentrations to a fixed concentration of androgens and monitor the combined effect on melanoma cell growth. Initially, human melanoma (BLM) cells were incubated in a 96 well plate with AD and T separately at an increasing concentrations. Mechanism of inhibition of cell growth was determined by carrying out assays for necrosis, apoptosis and autophagy. Progesterone at 10, 50, 100 µM concentrations were added to a fixed concentration of androgens and melanoma cell growth was monitored by MTT assay. Results showed that AD and T inhibited melanoma cell growth significantly only at 100 and 200 µM concentrations. The mechanism of inhibition at that concentrations was due to autophagy. Addition of progesterone as low as 10 µM concentration to androgens showed an additive effect on cell growth inhibition on top of significant inhibition by androgens alone. In conclusion, androgens might not be responsible for increased male mortality, perhaps deficiency of progesterone in males was responsible for increased mortality in melanoma. A similar kind of published study (2) showed a significant association between circulating estradiol and male breast cancer.

1)    Ramaraj, P. and Cox, JL. In-vitro Effect of Progesterone on Human Melanoma (BLM) Cell Growth – Int J Clin Exp Med 2014;7(11):3941-3953   2)    Brinton LA, Key TJ, Kolonel LN, Michels KB, Sesso HD, Ursin G, Van Den Eeden SK, Wood SN, Falk RT, Parisi D, Guillemette C, Caron P, Turcotte V, Habel LA, Isaacs CJ, Riboli E, Weiderpass E, Cook MB. Prediagnostic            Sex Steroid Hormones in Relation to Male Breast Cancer Risk. J Clin Oncol. 2015, 33(18):2041-50.

Nothing to Disclose: TH, KJ, PR

*Please take note of The Endocrine Society's News Embargo Policy at https://www.endocrine.org/news-room/endo-annual-meeting/pr-resources-for-endo

Sources of Research Support: This work was carried out with the financial assistance from:1)    KCOM Seed money for research  to P.R and 2)    Biomedical Sciences grant