Potential anti-tumor activity of 13.56 MHz alternating magnetic hyperthermia and chemotherapy on the induction of apoptosis in human colon cancer cell lines HT29 and HCT116 by up-regulation of Bax, cleaved caspase 3&9, and cleaved PARP proteins.

Background: The purpose of the present study was to evaluate the efficacy of chemo-magnetic hyperthermia (MH), a combination of alternating magnetic field (AMF) and superparamagnetic nanoparticles (SPIONs) coated with Polyethylene glycol-Poly(butyl acrylate)-Polyethylene glycol (PEG-PBA-PEG) carrying 5-Fluorouracil (5-Fu), at inducing apoptosis in the human cancer cell lines HT29 and HCT116. This process can be mediated by alterations in the expression of apoptotic effector proteins, including Bax, Bcl-2, cleaved caspase 3&9, and cleaved PARP, which are involved in the intrinsic pathway of apoptosis. For this purpose, the cells were cultured as monolayers. Then both cell lines were treated with 5-Fu/magnetic nanoparticles and magnetic hyperthermia. Finally, the effect of treatment on cancer cells was determined by Western blot analysis and flow cytometry. Results: Our results showed that combined chemo-magnetic thermotherapy significantly increased the apoptosis in colon cancer cells compared to chemotherapy or hyperthermia alone (P < 0.05). Up-regulation of Bax, cleaved caspase 3&9, and cleaved PARP proteins was indicative of apoptosis induction in cancer cells, which are involved in the intrinsic pathway of apoptosis. Conclusions: This study demonstrates that localized hyperthermia was able to significantly trigger the 5-Fu release and inhibit cell viability, which, due to the synchronization of hyperthermia and chemotherapy, exacerbated the damage of cancer cells. [ABSTRACT FROM AUTHOR]