Puerarin Induces Ferroptosis in Colorectal Cancer Cells via Triggering NCOA4 Upregulation.

Puerarin shows promise as an anti-cancer compound, but its mechanism of action remains unclear. Here we explored whether and how it promotes ferroptosis in a colorectal cancer cell line. The level of ferroptosis and expression of autophagy proteins were compared between puerarin-treated HT-29 cells expressing normal or reduced levels of the autophagy protein ATG5 or the ferritinophagy protein nuclear receptor coactivator 4 (NCOA4). Puerarin increased lipid peroxidation and inhibited cell proliferation in a dose-dependent manner, indicating the induction of ferroptosis. These effects were partially reversed by ferrostatin-1, a scavenger of reactive oxygen species; by the iron chelator deferiprone; by repression of autophagy through administration of 3-methyladenine or knockdown of autophagy-related gene 5 (ATG5); or by repression of ferritinophagy through NCOA4 knockdown. Puerarin may induce the proliferative inhibition of colorectal cancer cells by triggering ferroptosis through a mechanism requiring NCOA4 ferritinophagy.

microRNA-186 inhibition of PI3K-AKT pathway via SPP1 inhibits chondrocyte apoptosis in mice with osteoarthritis.

Chondrocyte apoptosis has been implicated as a major pathological osteoarthritis (OA) change in humans and experimental animals. We evaluate the ability of miR-186 on chondrocyte apoptosis and proliferation in OA and elucidate the underlying mechanism concerning the regulation of miR-186 in OA. Gene expression microarray analysis was performed to screen differentially expressed messenger RNAs (mRNAs) in OA. To validate the effect of miR-186 on chondrocyte apoptosis, we upregulated or downregulated endogenous miR-186 using mimics or inhibitors. Next, to better understand the regulatory mechanism for miR-186 governing SPP1, we suppressed the endogenous expression of SPP1 by small interfering RNA (siRNA) against SPP1 in chondrocytes. We identified SPP1 is highly expressed in OA according to an mRNA microarray data set GSE82107. After intra-articular injection of papain into mice, the miR-186 is downregulated while the SPP1 is reciprocal, with dysregulated PI3K-AKT pathway in OA cartilages. Intriguingly, miR-186 was shown to increase chondrocyte survival, facilitate cell cycle entry in OA chondrocytes, and inhibit chondrocyte apoptosis in vitro by modulation of pro- and antiapoptotic factors. The determination of luciferase activity suggested that miR-186 negatively targets SPP1. Furthermore, we found that the effect of miR-186 suppression on OA chondrocytes was lost when SPP1 was suppressed by siRNA, suggesting that miR-186 affected chondrocytes by targeting and depleting SPP1, a regulator of PI3K-AKT pathway. Our findings reveal a novel mechanism by which miR-186 inhibits chondrocyte apoptosis in OA by interacting with SPP1 and regulating PI3K-AKT pathway. Restoring miR-186 might be a future therapeutic strategy for OA.

Effects of miR-338 on morphine tolerance by targeting CXCR4 in a rat model of bone cancer pain.

The present study aimed to investigate the effects of miR-338 on morphine tolerance through the targeting of CXC chemokine receptor-4 (CXCR4) in a rat model of bone cancer pain (BCP). Sprague-Dawley (SD) rats were obtained and divided into model saline (n=10), model morphine (n=50), normal saline (n=10) and normal morphine (healthy rats, n=10) groups. After BCP rat model establishment, the remaining SD rats (n=40) in the model saline group were assigned into pLV-THM-miR-338, pLV-THM-anti-miR-338, CXCR4 shRNA, blank and PBS groups. Luciferase reporter gene assay was used for luciferase activity. Quantitative real-time PCR (qRT-PCR) and Western blotting were performed to detect the miR-338 and CXCR4 mRNA and protein expression. The model saline group showed increased mRNA and protein expressions of CXCR4 but decreased miR-338 compared with the model saline group, and the model morphine group had increased mRNA and protein expressions of CXCR4 but decreased miR-338 compared with the model saline group. The mRNA and protein expressions of miR-338 in the pLV-THM-miR-338 group increased remarkably while those of the pLV-THM-anti-miR-338 group decreased significantly compared with the CXCR4 shRNA, blank and PBS groups. The pLV-THM-miR-338, pLV-THM-anti-miR-338, CXCR4 shRNA and CXCR4 mRNA groups all had lower mRNA and protein expressions of CXCR4 than those in the blank and PBS groups. miR-338 exerts significant influence in the inhibition of morphine tolerance by suppressing CXCR4 in BCP.