The Effect of Vincristine on Hypoxic, Apoptotic, and Autophagic Gene Expressions in Gastric Cancer Cells under Hypoxic Conditions

Apoptosis and autophagy functions are known as death-inducing mechanisms. Vincristine (VCR) is a chemotherapeutic drug that binds with tubulin dimers and induces apoptosis in cancer cells. Furthermore, VCR protects cancer cells from apoptosis, allowing them to enter autophagy. This makes cancer even more aggressive in its latter stages. Herein, we aimed to investigate the effect of VCR on autophagy and apoptosis in gastric cancer AGS and MKN45 cells under hypoxic conditions. In this experimental approach, we performed cell culture, cell viability analysis, ribonucleic acid (RNA) isolation, cDNA synthesis, and observation of gene expression levels. Subsequently, the amount of acidic vesicular organelles was investigated with acridine orange staining. Through the use of quantitative real-time polymerase chain reaction, we studied the effect of hypoxia and VCR on mRNA levels of hypoxia-related vascular endothelium growth factor(VEGF) and hypoxia inducible factor-1a (HIF-1α), as well as apoptosis-related Bcl-2-associated X protein (Bax) and B-cell lymphoma 2 (Bcl-2), and autophagy-related Beclin-1 and microtubule-associated protein 1A/1B-light chain 3 (LC3-II) on AGS and MKN45 cell lines. The optimum VCR concentration was selected via cell viability analysis. The optimum VCR concentration was selected as 300 nM. VEGF, HIF- 1α, Bax, Bcl-2, and LC3-II mRNA expressions increased by 7.63, 3.34, 2.07, 4.09, and 3.1 folds, respectively, after VCR application to AGS cells under hypoxic conditions compared to the control cells. In MKN45 cells, Bax and LC3-II gene expressions increased by 5.21 and 12.2 folds, respectively, under the same conditions. In addition, the increase in the expression of autophagic LC3-II gene was consistent with acidic vesicular organelle formation. It was observed that VCR affects hypoxic, apoptotic, and autophagic gene expressions in AGS and MKN45 cells under hypoxic conditions.