Calycosin inhibits viability, induces apoptosis, and suppresses invasion of cervical cancer cells by upregulating tumor suppressor miR-375.

Calycosin, a functional phytoestrogen isoflavone isolated from Radix astragali, has been shown to possess multiple pharmacological properties including anti-cancer activity. However, up to now, the anti-cancer effect and the related mechanism of calycosin on cervical cancer (CC) cells have not been explored. It has been demonstrated that tumor suppressor miR-375 was downregulated in CC and calycosin upregulated miR-375 expression in cerebral ischemia/reperfusion. Thus we supposed that calycosin exerted anti-cancer effect by upregulating miR-375 expression in CC cells. Effects of calycosin or combined with miR-375 on cell viability and lactate dehydrogenase (LDH) release were detected by 3-(4,5)-dimethylthiahiazo (-z-y1)-3,5-di-phenytetra zoliumromide (MTT) and LDH release assay. Apoptosis, caspase-3 activity, and cell invasion were determined by flow cytometry, caspase-3 activity assay, and Transwell assay, respectively. miR-375 expression was detected by quantitative real-time PCR (qRT-PCR). Our results showed that Calycosin dose-dependently inhibited cell viability and increased LDH release in CC cells, suggesting the cytotoxic effect of calycosin on CC cells. Calycosin enhanced the apoptotic rate and caspase-3 activity and decreased the number of invaded cells in CC cells. In addition, we found that miR-375 expression was decreased in CC cells but was upregulated in response to calycosin. Mechanistically, knockdown of miR-375 significantly reversed the anti-cancer effect of calycosin on CC cells. In conclusion, calycosin inhibited viability, induced apoptosis, and suppressed invasion of CC cells by upregulating tumor suppressor miR-375.