Clinical significance of heat shock proteins in gastric cancer following hyperthermia stress: Indications for hyperthermic intraperitoneal chemoperfusion therapy.

Heat shock proteins (HSPs) are important factors in the response of cancer cells to thermo- and chemotherapy. Transient hyperthermic intraperitoneal chemoperfusion (HIPEC) therapy results in the upregulation of HSP expression, which may compromise the efficacy of additional anticancer treatments. The aim of the present study was to monitor the kinetics of HSP expression in tumor cells and patients with gastric cancer following HIPEC. Thus, in vitro and in vivo experiments were conducted to investigate the expression of two HSP family members, HSP70 and HSP90. Cells from two gastric tumor strains were subjected to HIPEC-mimicking treatment, and HSPs expression was analyzed at specific time points up to 48 h. Serum HSP concentrations were analyzed in patients with gastric cancer who had previously received cytoreductive surgery plus HIPEC treatment. The in vitro experiments indicated a significant elevation of HSP90 expression in gastric adenocarcinoma cells following hyperthermic treatment. However, HSP70 expression increased from 4 h up to 20 h post-exposure and decreased to normal levels 36 h post-exposure. Analysis of HSPs in serum samples collected from 22 patients with gastric cancer confirmed that serum HSP90 and HSP70 levels increased following HIPEC therapy, peaking at 18 h and returning to normal 24 h post-exposure. It is therefore advisable to apply the second round of HIPEC or chemotherapy at least 24 h following the first treatment to minimize any potential thermoresistance and chemoresistance of tumor cells.