RT Journal Article SR Electronic T1 Cell Death After High-LET Irradiation in Orthotopic Human Hepatocellular Carcinoma In Vivo JF In Vivo JO In Vivo FD International Institute of Anticancer Research SP 1 OP 9 VO 25 IS 1 A1 ANAÏS ALTMEYER A1 MIHAELA IGNAT A1 JEAN-MARC DENIS A1 NADIA MESSADDEQ A1 JOHN GUEULETTE A1 DIDIER MUTTER A1 PIERRE BISCHOFF YR 2011 UL http://iv.iiarjournals.org/content/25/1/1.abstract AB Hepatocellular carcinoma (HCC) represents the sixth most common cancer worldwide and a major health problem since the choice of treatment is limited due to chemo- and radio-resistance. It was previously reported that high linear energy transfer (LET) radiation induced massive autophagic cell death in the human HCC SK-Hep1 cell line in vitro. This study analyzed the effects of high-LET radiation on the same HCC tumor model, orthotopically transplanted into nude mice. For this purpose, after surgical xenograft in the liver, animals were irradiated with fast neutrons and cell death occurring in the tumors was assessed with various techniques, including electron microscopy and probe-based confocal laser endomicroscopy. Results indicate that considerable autophagy and only limited apoptosis took place in the tumor xenografts after high-LET irradiation. These data confirm the previous in vitro results, suggesting that autophagy may act as a predominant mode of cell death in the efficacy of high-LET radiation.