In lab studies of breast cancer cells, the hormone kisspeptin caused an increase in the gene that makes the estrogen‑producing enzyme aromatase, but only in one type of cancer cell (MCF7). This effect was blocked when the kisspeptin receptor was inhibited, and it did not happen in another breast cancer cell line (SKBR3). The findings suggest kisspeptin could boost estrogen production in certain cancer cells, which might make tumors more aggressive.

Kisspeptin is a reproductive peptide hormone that has anti-metastatic roles in several cancer types including colon, lung, and brain cancer. However, in breast cancer, increasing of kisspeptin expression induces aggressiveness of tumors, which in turn exacerbates breast cancer prognosis. Breast cancer cell lines MCF7 and SKBR3 were cultured in MEM (phenol red free) containing 10 % fetal bovine. Treatments were performed, at 70 % confluency, after 24-hour serum deprivation in serum free medium for 6, 24 and 48 hours. Aromatase (CYP19A1) and kisspeptin receptor (GPR54) mRNA expression were determined by real time Taqman Assay. Kisspeptin induced aromatase (CYP19A1) and kisspeptin receptor (GPR54) mRNA expression, while this induction was abolished by kisspeptin receptor inhibitor in MCF7 cells. In SKBR3 cells, however, even though there was an increase in GPR54 mRNA expression with kisspeptin, the induction of CYP19A1 was not observed. The inducing effect of kisspeptin on aromatase expression is possibly mediated via kisspeptin receptor and estrogen receptor dependent mechanisms (Fig. 5, Ref. 27).