GATA6 Reduces Pancreatic Cancer Cell Stemness by Modulating Wnt/β-Catenin Signaling

Abstract

Background: The stemness capacity of cancer cells has an important role in the initiation and development of pancreatic ductal adenocarcinoma (PDAC). An important regulator of cancer cell stemness is the Wnt/β-catenin signaling pathway. To further deepen the understanding of the pathogenesis of PDAC, the aim of this study was to investigate the regulatory mechanisms of cancer cell stemness. Methods: Genetic screening was performed to identify candidate proteins that might regulate cell stemness in PDAC. Subsequently, Western blot analysis and quantitative polymerase chain reaction (qPCR) assays were used to evaluate the expression of GATA Binding Protein 6 (GATA6) in PDAC cell lines. Stable cell lines expressing GATA6 were also established. Cell counting kit-8 (CCK8) assay, colony formation assay, and gemcitabine resistance assay were used to investigate the effect of GATA6 on the malignant behavior of PDAC cells. Experimental knockdown and overexpression groups were also studied. Western blot and qPCR assays were used to detect alterations in cancer stem cell characteristics after changing the GATA6 protein expression level in PDAC cells. Changes in the knockdown and overexpression groups were compared with controls. Dual-luciferase reporter assays and chromatin immunoprecipitation assays were also used to investigate the molecular mechanisms in this biological model. Results: Using a small range for overexpression screening, GATA6 overexpression was found to significantly reduce the stemness of PDAC cells. Furthermore, stably expressing cell lines were used to show that the malignant biological behavior of PDAC cells was significantly reduced following the overexpression of GATA6, and vice versa for the knockdown of GATA6 (p < 0.05). Western blot and qPCR assays showed that elevated GATA6 protein expression inhibited the stemness of PDAC cells through the Wnt/β-catenin signaling pathway (p < 0.01). Further experiments showed that GATA6 exerts its biological effects by binding to the β-catenin promoter region to inhibit its transcription. Conclusion: GATA6 can inhibit the stemness properties of PDAC cells via the Wnt/β-catenin signaling pathway.