Induction of necroptosis in lung adenocarcinoma by miR‑10b‑5p through modulation of the PKP3/RIPK3/MLKL cascade.

Abstract

Globally, lung adenocarcinoma (LUAD) remains the leading cause of cancer‑related mortality, highlighting the urgent need for innovative therapeutic approaches. Necroptosis has been recognized as a crucial mechanism for inhibiting cancer progression. Research has revealed a significant association between microRNA (miRNA)‑mediated necroptosis and tumor progression. The present study aimed to elucidate the role and underlying mechanisms of miR‑10b‑5p in regulating necroptosis in the context of LUAD. In an investigation of LUAD, miRNA sequencing was conducted on both LUAD and adjacent non‑tumor tissues, followed by the integration of external database information to identify specific target miRNAs. The expression of miR‑10b‑5p was verified in LUAD tissues and corresponding adjacent non‑cancerous tissues using immunohistochemistry. In vitro experiments, utilizing LUAD cell lines engineered to modulate miR‑10b‑5p levels, assessed its effects on cellular activities and necroptosis. The inhibition of PKP3 by miR‑10b‑5p was determined using a dual luciferase reporter system. Furthermore, alterations in miR‑10b‑5p levels were found to affect PKP3 expression and inhibit the RIPK3/MLKL signaling pathway, as evidenced by western blot analysis in LUAD cell lines. The effect of PKP3 knockdown on cell activity and necroptosis in LUAD cell lines with low miR‑10b‑5p expression levels was assessed using cell function assays. Finally, a nude mouse xenograft model was used to investigate the effect of miR‑10b‑5p on LUAD growth in vivo and its specific mechanism of action. It has been revealed that miR‑10b‑5p levels are significantly elevated in LUAD specimens. Further investigations demonstrated that an increase in miR‑10b‑5p enhances the proliferation of LUAD cells and suppresses the progression of necroptosis, as evidenced by in vitro experiments. Through dual luciferase reporter assays, PKP3 was confirmed as a direct target negatively regulated by miR‑10b‑5p, leading to reduced expression levels. Western blot analysis indicated that miR‑10b‑5p inhibits the RIPK3/MLKL pathway activation through downregulation of PKP3, which leads to increased cell proliferation and decreased necroptosis. However, knockdown of PKP3 reversed the inhibitory effect of miR‑10b‑5p inhibitors on cellular activity and inhibited necrosis by suppressing the RIPK3/MLKL signalling pathway. In addition, animal model studies demonstrated that inhibition of miR‑10b‑5p activated the RIPK3/MLKL pathway by promoting PKP3 expression and significantly reduced LUAD growth by promoting necroptosis. In conclusion, our studies have revealed that the miR‑10b‑5p functions as a tumorigenic factor, enhancing various cellular activities in LUAD cells and suppressing necroptosis by specifically targeting PKP3, thereby inhibiting activation of the RIPK3/MLKL pathway. Importantly, interventions using inhibitors that specifically target miR‑10b‑5p have shown significant success in impeding the progression of LUAD by promoting necroptosis in both cellular and animal models. Thus, targeting miR‑10b‑5p holds considerable potential as a therapeutic strategy for LUAD.