The study looked at kidney cancer cells and found that a small RNA called miR‑21 is higher in tumors, which then lowers two proteins, TCF21 and KISS1. Lower KISS1 makes the cancer cells more invasive, while adding extra KISS1 reduces their ability to spread. This work is about cancer biology, not about using kisspeptin‑10 as a supplement or health tool.

To investigate whether the microRNA-21 gene (miR-21) could regulate renal cancer cells invasion by downregulation of TFC21 and KISS1. Quantitative real-time polymerase chain reaction was applied to evaluate the expression level of miRNA-21 in renal cancer and normal renal cell samples. The regulated effects of miR-21 to TCF21 were detected by Western blot after pre/anti-miR-21 was transfected to Caki-1 cells. The luciferase activity assay was used to reveal the predicted target gene of miR-21 was direct and specific. Small interfering RNA-TCF21 was transfected to Caki-1 cells to inhibit the expression of the TCF21 gene. Next, the expression of the KISS1 gene was detected by Western blot in Caki-1 cells with TCF21 gene silencing. The expression vector, pcDNA3.1-KISS1, was transfected to Caki-1 cells to upregulate the expression of the KISS1 gene. The invasion ability of Caki-1 cells with KISS1 overexpression was analyzed using the Transwell assay. Our study showed that miR-21 was upregulated in human renal cell carcinoma specimens compared with its expression in normal renal cell specimens. Pre-miR-21 could upregulate the expression of miR-21 and downregulate the expression of TCF21, and anti-miR-21 showed the opposite effects. siRNA-TCF21 decreased the expression of the TCF21 protein, and the expression of KISS1 was downregulated in Caki-1 cells with TCF21 gene silencing. pcDNA3.1-KISS1 transfection upregulated the expression of the KISS1 protein, and the invasion ability of Caki-1 cells with KISS1 overexpression decreased markedly. Aberrantly expressed miR-21 might regulate the TCF21-KISS1-associated renal cell carcinoma cell invasion pathway, and this miRNA signature could offer a novel potential therapeutic strategy for renal cell carcinoma.