Page 128 - D. Cancer biology

[D. Cancer biology-80]

Effects of pregnenolone on the human breast cancer cells

Min Jae Kim¹, Sung-Min An¹, Da Som Kim¹, So Young Kim¹, Da Hee Kang¹, Beum-Soo An¹˙*

¹Biomaterials Science, Pusan National University, Miryang 50463, Republic of Korea

Estrogen is known to be a key hormone in the development of breast cancer. Previous studies have shown that
estrogen enhances cell proliferation via regulating its target gene expression in human breast cancer MCF-7 cell
line. Although the effect of estrogen on the carcinogenesis in breast, the effects of pregnenolone (PG), an inactive

precursor of estrogen, on MCF-7 cells or breast cancer have not been demonstrated. PG is a precursor in the

biosynthesis of most of the steroid hormones containing estrogen. In this study, we have analyzed the effects of
PG on cell proliferation and cell cycle-related protein expression. To explore the function of PG, MCF-7 cells were
treated with PG and cell viability was examined. In the BrdU assay results, PG increased the cell proliferation by

more than 40%. PG also induced expression of cell cycle related-proteins including CDK2 and cyclin D1. To reveal
the mechanism of PG, we performed RNA seq after treatment of PG in the MCF-7 cells. Interestingly, PG upregulated

mRNA expression of target genes of estrogen receptor alpha (ERα), which include pS2 and Ki-67 genes. In summary,
our results suggest that the PG stimulates the carcinogenic process by controlling cell cycle related-proteins and

ERα target genes in an independent way of estrogen.