Abstract 1244: Hyperthermia and chemotherapy mediated effects on tumor cell proliferation and heat shock protein expression in human colon cancer

Abstract

Abstract In patients with peritoneal carcinomatosis (PC) of gastrointestinal cancer hyperthermic intraperitoneal chemotherapy (HIPEC) represents a promising treatment option integrated into multimodal concepts. Heat shock proteins (HSP) play a major role in cellular stress response conferring increased resistance in tumor cells. Therefore we analyzed HSP expression profiles in tumor cells exposed to hyperthermic and chemotherapeutic stress. To mimic HIPEC-like conditions HT29 colon cancer cells were exposed to varying hyperthermic conditions for 60 min with additional 5-fluorouracil (5-FU) treatment. HSP expression was analyzed 30 min, 24 h, 48 h and 72 h after treatment using Western Blot and RT-qPCR. Untreated cells cultivated at 37°C served as controls. Additionally, effects on tumor cell proliferation were determined 24 h, 48 h and 72 h after treatment by MTS-assay. Hyperthermia caused temperature dependent upregulation of HSP27, HSP70, HSP72, and HSP90 gene and protein expression that was further increased by additional cytotoxic 5-FU treatment. 5-FU initiated progressive rise in HSP gene expression up to 72 h after 1 h exposure at normothermia as well as under hyperthermia. After isolated hyperthermia tumor cell proliferation was recovered at 72 h. Antiproliferative effects of 5-FU could not be enhanced by further increased hyperthermia. Antiproliferative effects of hyperthermia induced during HIPEC therapy seem to be negatively influenced by highly conserved HSP mechanisms. Our findings suggest that HSP27, HSP70/72, and HSP90 are significantly involved in hyperthermia and chemotoxicity mediated cell stress repair mechanisms. While initial increase in HSP expression can counteract cytotoxic effects during HIPEC therapy long-term elevated expression levels may cause lasting resistance to cellular stress. Note: This abstract was not presented at the meeting. Citation Format: Tanja Grimmig, Rebeca Thumm, Romana Moench, Eva M. Moll, Christoph T. Germer, Ana Maria Waaga-Gasser, Martin Gasser. Hyperthermia and chemotherapy mediated effects on tumor cell proliferation and heat shock protein expression in human colon cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1244. doi:10.1158/1538-7445.AM2015-1244