Wnt/β-catenin signaling activation by TIMP1 confers cisplatin-resistant gastric cancer cells to malignant behaviors and epithelial–mesenchymal transition

Abstract

Abstract Objectives Cisplatin (DDP) remains to be commonly employed in treating gastric cancer (GC) patients, particularly advanced-stage ones. However, acquired resistance to DDP often occurs, which causes a poor prognosis. This study aimed to understand the potential contribution of tissue inhibitor of metalloproteinase 1 (TIMP1) in acquired resistance to DDP in GC. Methods Bioinformatics analysis was performed to explore the relation of TIMP1 expression with stages and survival rate in GC. The TIMP1 expression between the parental and DDP-resistant GC cell lines were detected by quantitative reverse-transcription polymerase chain reaction (qRT-PCR). The effect of TIMP1 on the ability of cells against DDP was elevated by CCK-8, wounding healing, and transwell assays after exposing DDP. The role of TIMP1 in stemness and EMT process was explored through spheres formation assay and detecting stem cell- and EMT-related markers. Finally, the regulation of TIMP1 in Wnt/β-catenin signaling in DDP-resistant GC cells was also analyzed by western blot. Results Bioinformatics analysis revealed that TIMP1 is highly expressed and closely related to tumor stage and poor survival in GC. The TIMP1 expression of DDP-resistant GC cell lines was significantly higher than that of the parental one. CCK-8, wounding healing, and transwell assays showed that the tolerance to DDP of DDP-resistant AGS (AGS/DDP) cells was significantly augmented compared with that of parental AGS cells, revealed by increased IC50 and enhanced migration and invasion when exposed to DDP. Stronger stemness and epithelial–mesenchymal transition could be also observed in AGS/DDP cells. These malignant phenotypes were eliminated by silencing TIMP1 but aggravated by overexpressing TIMP1 in AGS/DDP cells. The use of the Wnt/β-catenin inhibitor could effectively reverse the function of TMIP1 overexpression in AGS/DDP cells, which suggested that the role of TIMP1 in DDP resistance relied on the Wnt/β-catenin signaling. Conclusions TIMP1 is an essential regulator of DDP resistance in GC, which may be a potential therapeutic target for cases that are refractory to DDP.