LINC00963/miR-4458 regulates the effect of oxaliplatin in gastric cancer by mediating autophagic flux through targeting of ATG16L1

Abstract

Oxaliplatin resistance is the greatest obstacle to the management of local recurrence in gastric cancer patients after surgery. Accumulating evidence has suggested that inhibiting autophagy may be a novel approach for reversing resistance to oxaliplatin treatment. In this manuscript, we aimed to investigate the role of LINC00963 in regulating autophagy and oxaliplatin resistance. qRT-PCR, immunochemistry staining, and western blotting were used to detect gene expression. Plasmids were used to up- and downregulate the expression of LINC00963 and miR-4458. A caspase 3/7 activity kit and flow cytometry were used to detect the apoptosis rate. CCK8 and Transwell assays were used to test cell proliferation and migration, respectively. Transmission electron microscopy and a dual fluorescent lentivirus autophagy system were used to evaluate autophagic flux. Dual luciferase reporter gene assays and RNA pulldown assays were used to evaluate the potential crosstalk. LINC00963 was highly expressed in gastric cancer patients and cell lines. In addition, high LINC00963 expression was found to be associated with poor prognosis and local recurrence in gastric cancer patients, indicating that LINC00963 might be involved in oxaliplatin resistance. Moreover, we found that LINC00963 was aberrantly highly expressed in oxaliplatin-resistant SGC-7901 (SGC-7901-R) cells and promoted proliferation and migration and reduced the apoptosis rate in SGC-7901-R cells. Furthermore, among all potential target microRNAs, miR-4458 was found to be negatively regulated by LINC00963 both in vivo and in vitro. In addition, miR-4458 overexpression led to impaired proliferation and migration and enhanced cell apoptosis and G1 arrest in SGC-7901-R cells. Further RNA pulldown and dual luciferase reporter gene assays indicated the interaction between LINC00963 and miR-4458. Moreover, we found enhanced autophagic flux in SGC-7901-R cells compared with SGC-7901 cells; in addition, an inhibitor of autophagy induced apoptosis in SGC-7901-R cells. Then, we found that downregulation of LINC00963 expression and upregulation of miR-4458 expression significantly suppressed autophagic flux in SGC-7901-R cells. Based on starBase V3.0 and dual luciferase reporter gene assays, we predicted and confirmed that ATG16L1 might be the target of miR-4458 to regulate autophagy. In conclusion, LINC00963 and miR-4458 are potential biomarkers for predicting the overall survival of gastric cancer patients. Moreover, targeting LINC00963 to inhibit autophagic flux sensitizes gastric cancer cells to oxaliplatin treatment, suggesting that it is a potential novel therapeutic target for improving oxaliplatin sensitivity.

FGF19 promotes cell autophagy and cisplatin chemoresistance by activating MAPK signaling in ovarian cancer

“…IL-6 activates autophagy through the upregulating JAK2 pathway and promotes chemotherapy resistance in colorectal cancer ( Hu et al, 2021 ). Furthermore, as promising regulators of autophagy, the non-coding RNAs, such as lncRNAs and miRNAs, can regulate therapeutic resistance in cancer cells ( Eng et al, 2021 ; Hou, Li & Dong, 2021 ; Xia et al, 2022 ). Moreover, increasing studies have confirmed that autophagy is involved in the progression and drug resistance of ovarian cancer cells ( Zhao et al, 2021 ).…”

The dual role of autophagy in the regulation of cancer treatment

“…According to Hu et al induction of autophagy via LINC00641/miR‑582‑5p axis promotes the resistance of gastric cells to oxaliplatin (Hu et al 2020 ). In a similar study by Hou et al LINC00963-induced autophagy promoted oxaliplatin resistance (Hou et al 2021 ). Relatedly, activation of autophagy through H19/SAHH/DNMT3B promoted resistance of breast cancer cells to tamoxifen (Wang et al 2019 ).…”

Regulation of autophagy by non-coding RNAs in gastric cancer

“…In addition, LINC00963, a new drug-resistant lncRNA, enhances proliferation and migration in oxaliplatin-resistant cells by negatively regulating miR-4458. Both downregulation of LINC00963 and upregulation of miR-4458 suppress autophagy by reducing the expression of ATG16, which indicates that targeting LINC00963 to block autophagy sensitizes GC cells to oxaliplatin ( 103 ). The miR188-3p/ATG14 axis is also targeted by lncRNA EIF3J-DT to activate autophagy and induce multiple chemotherapeutic drug resistance in GC cells ( 104 ).…”