[VDAC1 activates the PI3K/AKT/mTOR pathway to promote epithelial-mesenchymal transition and cell proliferation in lung adenocarcinoma].

Abstract

Objective: To explore the regulatory mechanism of voltage-dependent anion channel 1(VDAC1) on the proliferation, migration and invasion of lung adenocarcinoma(LUAD) cells. Methods: This study employed a combination of bioinformatics and experimental validation methods, conducting bioinformatics analysis and cytological experimental validation in the central laboratory of the School of Medicine, Anhui University of Science and Technology from February 2023 to August 2024.Clinical histological specimen validation was performed using immunohistochemistry, and a retrospective analysis was conducted on 5 cases of lung adenocarcinoma and adjacent samples from Huai'an First People's Hospital affiliated with Nanjing Medical University. The TCGA network database was analyzed for the expression pattern, prognostic value, and functional enrichment of VDAC1 in LUAD. A549 cells with VDAC1 knockdown and H1650 cells with VDAC1 overexpression were established through lentiviral transfection. The expression difference of VDAC1 protein in LUAD and adjacent tissue specimens was detected by immunohistochemistry.The effects of VDAC1 on the proliferation, migration, and invasion capabilities were explored through CCK8 assay, scratch healing assay, and Transwell assay.The activation levels of epithelial-mesenchymal transition (EMT) marker proteins, cell cycle-dependent kinases, and molecules in the PI3K/AKT/mTOR signaling pathway were detected by Western blot. Results: Bioinformatics analysis revealed that VDAC1 was highly expressed in LUAD cells (P<0.000 1) and was an independent risk factor for LUAD (P<0.000 1). Functional enrichment analysis showed significant enrichment of the PI3K/AKT/mTOR, G2M checkpoint, and P53 signaling pathways (P<0.001). Compared to adjacent control tissues, the expression level of VDAC1 protein is higher in lung adenocarcinoma tissues.Overexpression of VDAC1 promoted the proliferation (P<0.000 1), migration, and invasion(P<0.01) of H1650 cells, while knockdown of VDAC1 inhibited the proliferation (P<0.000 1), migration, and invasion (P<0.05) of A549 cells.Western Blot experiments showed that compared to the control group, the expression levels of vimentin (1.10±0.11 vs 2.39±0.15, P<0.001), N-cadherin (0.94±0.12 vs 2.72±0.06, P<0.001), CDK1 (0.93±0.04 vs 1.53±0.03, P<0.000 1), CDK2 (1.04±0.13 vs 2.29±0.06, P<0.001), CDK4 (0.90±0.03 vs 2.00±0.11, P<0.01), p-PI3K (1.08±0.13 vs 1.85±0.12, P<0.01), and p-AKT (1.03±0.11 vs 1.69±0.06, P<0.001) were increased in H1650 cells overexpressing VDAC1, while E-cadherin expression decreased (2.18±0.14 vs 0.997±0.11, P<0.001).In contrast, in A549 cells with VDAC1 knockdown, the expression levels of vimentin (1.70±0.26 vs 0.97±0.09, P<0.05), N-cadherin (1.98±0.25 vs 1.03±0.06, P<0.05), CDK1 (1.13±0.03 vs 0.95±0.02, P<0.01), CDK2 (2.29±0.12 vs 0.92±0.10, P<0.001), CDK4 (1.71±0.096 vs 1.12±0.11, P<0.01), p-PI3K (1.67±0.09 vs 0.97±0.03, P<0.001), and p-AKT (1.53±0.04 vs 1.02±0.03, P<0.000 1) decreased, while E-cadherin expression increased (1.04±0.04 vs 1.85±0.26, P<0.05). Conclusions: VDAC1 may promote the proliferation, migration, and invasion of LUAD cells by activating EMT and cyclin-dependent kinases through the PI3K/AKT/mTOR pathway.