Investigation of the effects of hyperthermia and curcumin on cancer stem cell-like features and epithellial-mesenchimal transformation in breast cancer cells under hypoxia conditions

It is known that breast cancer is a heterogeneous disease, hypoxia plays an active role in invasion and metastasis and is associated with poor prognosis. The aim of this study is to examine and investigate the effects of Hyperthermia, 17-AAG and Curcumin triple therapy on gene expressions and cellular functions of CSC and EMT markers in breast cancer cell lines under hypoxia condition. In this study, firstly, HIF1A expression levels of CoCl2 in breast cancer cell lines were investigated by dose- and time-dependent qRT-PCR method to create hypoxia condition. As a result, it was found that the incubation of the MDA-MB-231 cell line with 25 µM at the 3rd hour and the incubation of the CRL-2329 cell line with 100 µM CoCl2 at the 3rd hour showed the highest HIF1A gene expression level. In our study, IC50 doses of 17-AAG and curcumin active substances at 24 and 48 hours were determined in hypoxia-induced breast cancer cell lines by MTT assay. Depending on these determined doses, combined groups were formed with hyperthermia. In our study, it was observed that HT + 17-AAG + Curcumin triple therapy applied to hypoxia-induced cell lines; significantly reduced the mRNA expression levels of cancer stem cell marker and epithelial mesenchymal transition-related marker genes in the hypoxia group compared to the groups where only HT and HT + 17-AAC were administered. In addition, according to the findings obtained by the cell migration assay, it was determined that this combination has antiproliferative and antiangiogenic effects on cells. These data indicate that it may be a very good combination agent in hypoxic breast tumors that overexpress CSC and EMT markers. Keywords: Breast Cancer, Hypoxia, Hyperthermia, 17-AAG, Curcumin, CSC, EMT