Lan Yang1, Ya Wen2, Guoqing Lv3, Yuntao Lin4, Junlong Tang4, Jingxiao Lu4, Manqiao Zhang2, Wen Liu4, Xiaojuan Sun5. 1. Shenzhen Tumor Immuno-gene Therapy Clinical Application Engineering Lab, Biobank of Shenzhen Second People's Hospital, The First Affiliated Hospital of Shenzhen University, Shenzhen 518035, PR China; Institute of Immunology of Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou 510060, Guangdong, PR China. 2. Shenzhen Tumor Immuno-gene Therapy Clinical Application Engineering Lab, Biobank of Shenzhen Second People's Hospital, The First Affiliated Hospital of Shenzhen University, Shenzhen 518035, PR China; Department of Graduate School, Guangzhou Medical University, Guangzhou 511436, PR China. 3. Department of Gastrointestinal Surgery, Peking University Shenzhen Hospital, Shenzhen 518035, PR China. 4. Shenzhen Tumor Immuno-gene Therapy Clinical Application Engineering Lab, Biobank of Shenzhen Second People's Hospital, The First Affiliated Hospital of Shenzhen University, Shenzhen 518035, PR China. 5. Shenzhen Tumor Immuno-gene Therapy Clinical Application Engineering Lab, Biobank of Shenzhen Second People's Hospital, The First Affiliated Hospital of Shenzhen University, Shenzhen 518035, PR China. Electronic address: xiaojuansun1978@163.com.
Abstract
BACKGROUND: Alpha lipoic acid (α -LA) is a naturally occurring antioxidant and metabolic enzyme co-factor. Recently, α -LA has been reported to inhibit the growth of various cancer cells, but the precise signaling pathways that mediate the effects of α -LA on non-small cell lung cancer (NSCLC) development remain unclear. METHODS: The CCK-8 assay was used to assess cell proliferation in NSCLC cell lines after α -LA treatment. The expression of growth factor receptor-bound protein 2 (Grb2), cyclin-dependent kinase (CDK)-2, CDK4, CDK6, Cyclin D3, Cyclin E1, Ras, c-Raf, epidermal growth factor receptor (EGFR), ERK1/2 and activated EGFR and ERK1/2 was evaluated by western blotting. Grb2 levels were restored in α-LA-treated cells by transfection of a plasmid carrying Grb2 and were reduced in NSCLC cells via specific siRNA-mediated knockdown. RESULTS: α -LA dramatically decreased NSCLC cell proliferation by downregulating Grb2; in contrast, Grb2 overexpression significantly prevented α-LA-induced decrease in cell growth in vitro. Western blot analysis indicated that α-LA decreased the levels of phospho-EGFR, CDK2/4/6, Cyclins D3 and E1, which are associated with the inhibition of G1/S-phase transition. Additional experiments indicated that Grb2 inhibition partially abolished EGF-induced phospho-EGFR and phospho-ERK1/2 activity. In addition, α-LA exerted greater inhibitory effects than gefitinib on NSCLC cells by preventing EGF-induced EGFR activation. CONCLUSION: For the first time, these findings provide the first evidence that α-LA inhibits cell proliferation through Grb2 by suppressing EGFR phosphorylation and that MAPK/ERK is involved in this pathway.
BACKGROUND:Alpha lipoic acid (α -LA) is a naturally occurring antioxidant and metabolic enzyme co-factor. Recently, α -LA has been reported to inhibit the growth of various cancer cells, but the precise signaling pathways that mediate the effects of α -LA on non-small cell lung cancer (NSCLC) development remain unclear. METHODS: The CCK-8 assay was used to assess cell proliferation in NSCLC cell lines after α -LA treatment. The expression of growth factor receptor-bound protein 2 (Grb2), cyclin-dependent kinase (CDK)-2, CDK4, CDK6, Cyclin D3, Cyclin E1, Ras, c-Raf, epidermal growth factor receptor (EGFR), ERK1/2 and activated EGFR and ERK1/2 was evaluated by western blotting. Grb2 levels were restored in α-LA-treated cells by transfection of a plasmid carrying Grb2 and were reduced in NSCLC cells via specific siRNA-mediated knockdown. RESULTS: α -LA dramatically decreased NSCLC cell proliferation by downregulating Grb2; in contrast, Grb2 overexpression significantly prevented α-LA-induced decrease in cell growth in vitro. Western blot analysis indicated that α-LA decreased the levels of phospho-EGFR, CDK2/4/6, Cyclins D3 and E1, which are associated with the inhibition of G1/S-phase transition. Additional experiments indicated that Grb2 inhibition partially abolished EGF-induced phospho-EGFR and phospho-ERK1/2 activity. In addition, α-LA exerted greater inhibitory effects than gefitinib on NSCLC cells by preventing EGF-induced EGFR activation. CONCLUSION: For the first time, these findings provide the first evidence that α-LA inhibits cell proliferation through Grb2 by suppressing EGFR phosphorylation and that MAPK/ERK is involved in this pathway.
Authors: Agnieszka Dawczak-Dębicka; Joanna Kufel-Grabowska; Mikołaj Bartoszkiewicz; Adrian Perdyan; Jacek Jassem Journal: Int J Environ Res Public Health Date: 2022-04-21 Impact factor: 4.614
Authors: Christelle Debeissat; Maryse Avalon; Mathilde Huart; Pascale Duchez; Laura Rodriguez; Marija Vlaski-Lafarge; Zoran Ivanovic; Philippe Brunet de la Grange Journal: Biomolecules Date: 2022-03-11