title: Modification of thermosensitivity by amrubicin or amrubicinol in human lung adenocarcinoma A549 cells and the kinetics of apoptosis and necrosis induction.
abstract: The effects of amrubicin (AMR) and its active metabolite, amrubicinol (AMROH), on the sensitivity of human lung adenocarcinoma A549 cell line to hyperthermia at 44 degrees C were investigated. The cell phase response as well as the kinetics of apoptosis and necrosis induction were also analyzed. The cytocidal effects of 44 degrees C hyperthermia on A549 cells exhibited low thermosensitivity with a T(0) value of 12 min. The slope of the survival curve in the exponential phase, described semilogarithmically, in 44 degrees C hyperthermia combined treatment with AMROH (0.02 microg/ml) was approximately parallel to 44 degrees C hyperthermia alone. The initial shoulder shape portion of the survival curve from 44 degrees C hyperthermia alone, indicating the repair of sublethal thermal damage (SLTDR), was reduced with the sequential combined treatment of AMR or AMROH. Sequential treatments with AMR or AMROH prior to 44 degrees C hyperthermia resulted in additive thermo-enhancement effect by reducing not only survival but was shoulder wide. Furthermore, like AMR and AMROH, adriamycin (ADM) and etoposide (VP-16) are DNA topoisomerase II inhibitors, and the effects of these 4 agents on 44 degrees C hyperthermia were compared. All 4 agents exhibited comparable thermo-enhancement effects. Using synchronized A549 cells, AMR or AMROH did not elicit cell phase responses, irrespective of the concentration. The induction of apoptosis was investigated at 48 and 72 h after AMROH treatment, 44 degrees C hyperthermia or the combined treatment, in which apoptosis was not significantly induced after any treatment. Furthermore, the incidence of necrosis was examined as well as apoptosis. The incidence of necrosis at 48 and 72 h after AMROH was 2.4 and 4.3%, respectively; after 44 degrees C hyperthermia was 3.3 and 4.0%, respectively; and after the combined treatment it was 10.7 and 8.7%, respectively. The necrosis induced after the combined treatment was circa 3 times higher than that in either of the single treatments.
authors.affiliation: Department of Experimental Radiology, Faculty of Medical Science, Fukui University, Matsuoka, Japan. hayashis@fmsrsa.fukui-med.ac.jp
authors.forename: Sachiko
authors.initials: S
authors.lastname: Hayashi
authors.forename: Masanori
authors.initials: M
authors.lastname: Hatashita
authors.forename: Hideki
authors.initials: H
authors.lastname: Matsumoto
authors.forename: Zhao-Hui
authors.initials: ZH
authors.lastname: Jin
authors.forename: Hiroki
authors.initials: H
authors.lastname: Shioura
authors.forename: Eiichi
authors.initials: E
authors.lastname: Kano
mesh_terms: D000230:Adenocarcinoma / Q000473:pathology / Q000503:physiopathology; D018943:Anthracyclines / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D004317:Doxorubicin / Q000494:pharmacology; D004357:Drug Synergism; D005047:Etoposide / Q000494:pharmacology; D006358:Hot Temperature; D006801:Humans; D008175:Lung Neoplasms / Q000473:pathology / Q000503:physiopathology; D009336:Necrosis / Q000139:chemically induced; D013997:Time Factors
chemical_list: D018943:Anthracyclines; C116173:amrubicinol; D005047:Etoposide; D004317:Doxorubicin; C055866:amrubicin