Tonsil-Derived Mesenchymal Stem Cells Inhibit the Proliferation of Hematological Cancer Cells through Downregulation of IL-6 Gene Expression under Hyperthermia

Abstract: Stem cells are extensively being studied as promising biological therapeutic candidates in cancer treatment. In various cancer types, some studies show proliferative effects while others show inhibitory effects of MSCs on tumors. Some studies have reported that MSCs isolated from different sources display different anti-cancer properties. Tonsils are one of the secondary lymphoid organs that form an important part of the immune system and located at the mucosal interface. The relation between secondary lymphoid organs and cancer progression lead us to investigate the effect of tonsil-derived MSCs (T-MSC) on cancer treatment. Therefore, we aimed to determine the anti-tumoral effects of tonsil-derived MSCs cultured at febrile temperature on hematological cancer cell lines. We found that co-culture of K562 cells and MOLT-4 with T-MSCs significantly decreased the viable cell number post 7 days of the culture under the febrile and normal culture conditions. Besides, the T-MSC co-culture not only induced the apoptosis on K562 and MOLT-4 cells but also, induced the cell cycle arrest at G2-M phase on MOLT-4 cells. The apoptotic effect of T-MSC co-culture under febrile stimulation was confirmed by upregulation of Bax, c-myc genes for K562 cells and upregulation of Bax, p53 and c-myc genes for MOLT-4 cells in transcriptional level. Our study has contributed to highlight the effect of the cellular interaction between the T-MSCs and human hematological cancer cells during in vitro co-culture under hyperthermia for tumor progression. In the light of these results, we indicated that tonsil-derived MSCs have promising therapeutic potential for cancer therapy.