F26 ENHANCED EXPRESSION OF SRY AND SOX9 GENES IN BALDING SCALP OF MEN WITH ANDROGENETIC ALOPECIA

¹WenChieh Chen, ²Ren-Yu Tsai, ¹Wen-Chuan Hsieh. ¹Dept. of Dermatology, National Cheng Kung University, Tainan, Taiwan; ²Dept. of Dermatology, Taipei Medical College, Taipei, Taiwan.

The pathophysiology of androgenetic alopecia (AGA) is believed to be closely related to (1) the activity of some steroidogenic enzymes, especially 5 alpha-reductase, and (2) the structure and function of androgen receptors. The current genetic studies did not show significant association between AGA and the genes encoding the two 5 alpha-reductase isoenzymes. The molecular control of gonadal differentiation has been greatly clarified over the past ten years. The genes WT1 and SF1 hasve been demonstrated to be involved in the formation of the gonads prior to their differentiation as testes or ovaries. Subsequent sex-specific gonadal differentiation appears to be mediated by the SRY and SOX9 genes in the testis, and the DAX-1 gene in the ovary. Since the skin, like testis and adrenal cortex, is revealed to also be a steroidogenic organ, possessing almost all the enzymes required for androgen metabolism, it would be interesting to study the cutaneous expression of those genes that regulate the transactivation of the steroidogenic enzymes in AGA patients. Skin specimens from frontal balding versus occipital hairy scalps were taken from the same individual of total 6 male AGA patients, stage III-IV (Norwood/Hamilton), during hair transplantation procedure. By RT-PCR examination of the whole skin extract, we have detected abundance of SRY and SOX9 but small amount of DAX-1 and WT1 in the scalp. Enhanced expression of SRY and SOX9 was observed in the balding areas, as compared to the hairy scalps (6/6). Lower level of WT1 expression was seen in the balding scalps (2/6). The expression of SF1 was barely detectable. Further investigation on the isolated hair follicles from larger population groups (normal vs. AGA, male vs. female) is needed to better understand the roles of these sex-determining genes in AGA.