Regulation and molecular mechanism of adiponectin on the proliferation, apoptosis, autophagy, and chemosensitivity of LN18 Glioma cell line.

This study aimed to explore the regulatory effects and associated mechanisms of adiponectin on apoptosis and proliferation in the LN18 glioma cell line through the AMPK and Akt signaling pathways. Additionally, we sought to elucidate the impact of adiponectin on the chemosensitivity of the LN18 glioma cell line to temozolomide (TMZ). The proliferation rate of glioma cells treated with adiponectin was assessed using the cholecystokinin (CCK8) assay. The Western blot analysis was employed to assess the expression of p-Akt, p-AMPK, p-mTOR, cleaved caspase3, Bax, Cyclin D1, and Cyclin B1 following adiponectin treatment. Cell apoptosis was quantified using AnnexinV/PI flow cytometry, while changes in the cell cycle were detected using PI staining flow cytometry. The findings revealed that adiponectin upregulates p-AMPK expression and downregulates p-mTOR expression in the PTEN wild-type glioma cell line LN18, with no discernible effect on p-Akt expression. Moreover, adiponectin inhibits the proliferation rate of the PTEN wild-type glioma cell line LN18, enhances the expression of cleaved caspase3 and Bax, and significantly elevates the apoptosis rate, as evidenced by AnnexinV/PI flow cytometry. Adiponectin was observed to suppress the expression of Cyclin D1 and Cyclin B1, increase the number of cells in the G1 phase, and promote autophagy. Additionally, adiponectin augments the expression of Beclin1 and the ratio of LC3II/I in the PTEN wild-type glioma cell line LN18, while decreasing p62 expression. In conclusion, this study posits that adiponectin holds therapeutic promise for glioma treatment. Furthermore, adiponectin enhances the inhibitory effect of TMZ on the proliferation rate of LN18 cells when treated with 0.1 mM and 1 mM TMZ. These results collectively suggest that adiponectin impedes proliferation, encourages apoptosis and autophagy in the LN18 glioma cell line, and heightens its sensitivity to the chemotherapeutic drug TMZ.