Research of heavy-ion radiobiology can be divided into two fields: for the heavy-ion radiotherapy and for the protection from the space radiation. Heavy-ion beams have definite advantages over the photon beams to treat many human cancers, especially effective in treating radioresistant tumors. Over the past 25 years, we have treated more than 11000 patients with many different cancer types using carbon-ion beams and achieved promising results. Here I try to present our cutting-edge research exploring mechanisms of how carbon-ion beams alone or in combination with DNA damaging drugs in targeting radioresistant cancer stem cells (CSCs). We found that carbon ion beam combined with DNA damaging drugs (gemcitabine or cisplatin) or with micro RNA 200c mimic significantly inhibited colony and spheroid formation capability of CSCs. Carbon ion beam combined with DNA damaging drugs significantly induced complex DNA damage, apoptosis- and autophagy-related gene expression compared to carbon ion alone in several cancer cells. Xenograft tumors from pancreatic, breast cancer and mesothelioma cells were effectively disrupted by 25 Gy of carbon ion beam combined with gemcitabine for pancreatic xenograft tumors or 15 Gy of carbon ion beam combined with cisplatin for breast and mesothelioma xenograft tumors. Taken together, carbon ion beam combined with DNA damaging drugs or with microRNA 200 mimic has high potential to kill pancreatic, breast and mesothelioma CSCs.7th international systems radiation biology worksho
