Precision hyperthermia-induced HSP20 inhibits gastric cancer cell invasion, migration, and proliferation.

[BACKGROUND] Many different types of human malignancies overexpress heat shock proteins (HSPs), which function as oncogenic regulators and control tumorigenesis. However, their contribution to gastric cancer (GC) remains unclear.

[OBJECTIVES] This study aimed to investigate the roles of HSP20 during high-temperature intraperitoneal chemotherapy for GC.

[METHOD] Immunohistochemistry and western blotting analysis were used to assess the levels of HSP20. Wild-type human HSP20 was sustainably overexpressed in AGS and HGC-27 cells (HSP20-overexpressing cells). The role of HSP20 in GC cells was further examined using cell counting kit-8, colony-formation, wound healing, and Boyden chamber assays. Western blotting analysis was used to detect how HSP20 affected the migration and proliferation of GC cells by regulating the expression levels of matrix metalloproteinase (MMP)2/MMP9 and cleaved-caspase3/cleaved-caspase 9.

[RESULTS] The results suggested that HSP20 shows low expression in GC tissues. We also found that the tumor-node-metastasis stage and pathological grade all correlated with the HSP20 level in GC. In some GC cells, high temperature (43 ℃) increased the expression of HSP20; however, in other cancer cells, HSP20 levels did not change significantly. In addition, after HSP20 overexpression in GC cells, their colony formation, proliferation, and migration abilities decreased markedly. Finally, overexpression of HSP20 significantly increased the expression of cleaved-caspase3/cleaved-caspase9 and BCL2 associated X protein (BAX) in GC cells.

[CONCLUSION] Overexpression of HSP20 promoted apoptosis cascades in GC cells and inhibited their proliferation, invasion, and migration.