shRNA Glut-1 inhibits cell viability, apoptosis and migration of laryngeal carcinoma HEp-2 cells through regulating Beclin-1-mediated autophagy

Abstract

Objective: Glut-1 is a key regulator in the process of glucose uptake. Previous studies have shown that Glut-1 affects autophagy. However, it is unclear whether there is a correlation between Glut-1 and autophagy in the progression of laryngeal carcinoma.This study was performed to investigate the role of Glut-1 in the development of laryngeal carcinoma.Methods: A stable HEp-2 cell model was constructed by Glut-1 and Beclin-1 shRNA lentiviral infection. The autophagosome was measured by transmission electron microscopy. Protein levels of LC3, ATG5, CyclinD1, Bcl-2, Caspase-3, and c-Myc were determined by Western blotting. CCK8 assay and Transwell assays were used to determine cell viability and migration rate of HEp-2 cells, respectively. Flow cytometry was performed to analyze the rate of apoptosis. Immunofluorescence was performed to determine the expression distribution of LC3. Results:Glut-1 knockdown significantly promoted autophagosome formation by upregulating the ratio of LC3-II/LC3-I as well as the role of rapamycin (RAP) andBeclin-1 overexpression on autophagy flux in HEp-2 cells. Glut-1 inhibition also reduced the viability of HEp-2 cells followed by the decreases in expression of cyclinD1 and c-Myc. In addition, Glut-1 depletion increased the number of apoptotic HEp-2 cells accompanied by activation of caspase-3 and downregulation of Bcl-2.Glut-1 knockdown also reduced the migration rate of HEp-2 cells by promoting the expression of N-cadherin and inhibiting the expression of E-cadherin. Beclin-1 consumption significantly reversed Gult-1 knockdown-mediated autophagy activation, resulting in promotion of both proliferation and migration and inhibition of apoptosis. Conclusions:Glut-1 knockdown-induced autophagy inhibits the proliferation and migration of HEp-2 cells, and promotes apoptosis of HEp-2 cells partly by regulating autophagy.

An appraisal of the current status of inhibition of glucose transporters as an emerging antineoplastic approach: Promising potential of new pan-GLUT inhibitors

“…Given such intimacy between various miRNAs and GLUT isoforms, there is a strong logic to utilize them in therapeutic applications. Similarly, a study on the role of MiR-218 and MiR340 in the expression of GLUT1 is demonstrated in oral squamous cell carcinoma (OSCC) ( Xu et al, 2018 ; Wang et al, 2020 ; Shiah et al, 2021 ). Combinatorial use of miRNAs with other conventional GLUT1 inhibitors is also needed to be explored to circumvent GLUT at both gene expression and protein function levels.…”

“…Similarly, the use of shRNA to GLUT1 was observed to show promising outcomes in colon cancer cells ( Bai et al, 2019 ). Wang et al (2020) demonstrated that shRNA inhibits the survival of laryngeal carcinoma HEP2 cells via beclin-1-associated autophagy. shRNA to GLUT1 is also reported to effectively block glucose uptake in various cancer cell lines ( Pliszka and Szablewski, 2021 ).…”