HSP70 promotes pancreatic cancer cell epithelial-mesenchymal transformation and growth via the NF-κB signaling pathway.

Abstract

Objective: To study the effects of HSP70 on proliferation, migration, invasion, and epithelial-mesenchymal transformation (EMT) of pancreatic cancer cells and explore its underlying mechanisms.

Methods: Pancreatic cancer cell models with either reduced HSP70 or increased HSP70 expression were established. RT-qPCR and Western blot assays were used to determine mRNA and protein levels of HSP70, IKK/IκBa/NF-κB signaling pathway-related genes, and EMT markers. The CCK-8 and cell cloning assays were used to evaluate cell proliferation and cloning abilities. Transwell and wound healing assays were used to assess the invasive and migratory properties of the cells. Effects of NF-κB signaling modulation were explored using an IKK inhibitor (BAY11-7082) and an IKK overexpression vector (pCMV-IKK). Electrophoretic mobility shift assay (EMSA) and luciferase reporter assays were conducted to analyze NF-κB's promoter binding and transcriptional activities.

Results: HSP70 knockdown inhibited p-p65 nuclear translocation and reduced the expression of p-p65, p-IKKα/β, p-IκBα, N-cadherin, Vimentin, and Twist. It also decreased NF-κB's promoter binding and transcriptional activities, increased E-cadherin levels, and suppressed pancreatic cancer cell proliferation, cloning, migration, and invasion. In contrast, HSP70 overexpression led to increased expression of p-p65, p-IKKα/β, p-IκBα, N-cadherin, Vimentin, and Twist, decreased E-cadherin levels, and enhanced cell proliferation, cloning, migration, and invasion capabilities. NF-κB signaling pathway modulation reversed EMT changes induced by altered HSP70 expression levels. rhHSP70 also increased p-IKKα/β and p-IκBα protein levels.

Conclusion: HSP70 promotes the EMT and enhances pancreatic cancer cell proliferation, migration, and invasion by activating the NF-κB pathway.