title: Effective elimination of cancer stem cells by magnetic hyperthermia.
abstract: Cancer stem cells (CSCs) are a subpopulation of cancer cells that have stem cell-like properties and are thought to be responsible for tumor drug resistance and relapse. Therapies that can effectively eliminate CSCs will, therefore, likely inhibit tumor recurrence. The objective of our study was to determine the susceptibility of CSCs to magnetic hyperthermia, a treatment that utilizes superparamagnetic iron oxide nanoparticles placed in an alternating magnetic field to generate localized heat and achieve selective tumor cell kill. SPIO NPs having a magnetite core of 12 nm were used to induce magnetic hyperthermia in A549 and MDA-MB-231 tumor cells. Multiple assays for CSCs, including side population phenotype, aldehyde dehydrogenase expression, mammosphere formation, and in vivo xenotransplantation, indicated that magnetic hyperthermia reduced or, in some cases, eliminated the CSC subpopulation in treated cells. Interestingly, conventional hyperthermia, induced by subjecting cells to elevated temperature (46 °C) in a water bath, was not effective in eliminating CSCs. Our studies show that magnetic hyperthermia has pleiotropic effects, inducing acute necrosis in some cells while stimulating reactive oxygen species generation and slower cell kill in others. These results suggest the potential for lower rates of tumor recurrence after magnetic hyperthermia compared to conventional cancer therapies.
authors: Department of Pharmaceutics, College of Pharmacy, University of Minnesota, Minneapolis, Minnesota 55455, USA.
authors: Tanmoy
authors: T
authors: Sadhukha
authors: Lin
authors: L
authors: Niu
authors: Timothy Scott
authors: TS
authors: Wiedmann
authors: Jayanth
authors: J
authors: Panyam
mesh_terms: D000444:Aldehyde Dehydrogenase / Q000378:metabolism; D000818:Animals; D045744:Cell Line, Tumor; D005260:Female; D005290:Ferric Compounds / Q000737:chemistry; D006801:Humans; D006979:Hyperthermia, Induced / Q000379:methods*; D008280:Magnetics; D058185:Magnetite Nanoparticles / Q000737:chemistry*; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D009336:Necrosis; D014411:Neoplastic Stem Cells / Q000187:drug effects* / Q000378:metabolism; D010316:Particle Size; D010641:Phenotype; D017382:Reactive Oxygen Species; D017550:Spectroscopy, Fourier Transform Infrared; D013696:Temperature; D014183:Transplantation, Heterologous
chemical_list: D005290:Ferric Compounds; D058185:Magnetite Nanoparticles; D017382:Reactive Oxygen Species; C000499:ferric oxide; D000444:Aldehyde Dehydrogenase