title: Cytoprotective effect of imatinib mesylate in non-BCR-ABL-expressing cells along with autophagosome formation.
abstract: Treatment with imatinib mesylate (IM) results in an increased viable cell number of non-BCR-ABL-expressing cell lines by inhibiting spontaneous apoptosis. Electron microscopy revealed an increase of autophagosomes in response to IM. IM attenuated the cytotoxic effect of cytosine arabinoside, as well as inhibiting cell death with serum-deprived culture. Cytoprotection with autophagosome formation by IM was observed in various leukemia and cancer cell lines as well as normal murine embryonic fibroblasts (MEFs). Complete inhibition of autophagy by knockdown of atg5 in the Tet-off atg5(-/-) MEF system attenuated the cytoprotective effect of IM, indicating that the effect is partially dependent on autophagy. However, cytoprotection by IM was not mediated through suppression of ROS production via mitophagy, ER stress via ribophagy, or proapoptotic function of ABL kinase. Although the target tyrosine kinase(s) of IM remains unclear, our data provide novel therapeutic possibilities of using IM for cytoprotection.
authors.affiliation: Department of Biochemistry, Tokyo Medical University, Tokyo, Japan.
authors.forename: Tadashi
authors.initials: T
authors.lastname: Ohtomo
authors.forename: Keisuke
authors.initials: K
authors.lastname: Miyazawa
authors.forename: Munekazu
authors.initials: M
authors.lastname: Naito
authors.forename: Shota
authors.initials: S
authors.lastname: Moriya
authors.forename: Masahiko
authors.initials: M
authors.lastname: Kuroda
authors.forename: Masahiro
authors.initials: M
authors.lastname: Itoh
authors.forename: Akio
authors.initials: A
authors.lastname: Tomoda
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D001343:Autophagy / Q000187:drug effects* / Q000235:genetics; D000071187:Autophagy-Related Protein 5; D001549:Benzamides; D045744:Cell Line, Tumor; D019610:Cytoprotection; D016044:Fusion Proteins, bcr-abl / Q000235:genetics / Q000378:metabolism*; D055785:Gene Knockdown Techniques; D006801:Humans; D000068877:Imatinib Mesylate; D008869:Microtubule-Associated Proteins / Q000235:genetics; D010588:Phagosomes / Q000187:drug effects* / Q000235:genetics; D010879:Piperazines; D047428:Protein Kinase Inhibitors / Q000494:pharmacology*; D011505:Protein-Tyrosine Kinases / Q000235:genetics / Q000378:metabolism*; D011743:Pyrimidines / Q000096:biosynthesis; D017382:Reactive Oxygen Species / Q000378:metabolism
chemical_list: C502778:ATG5 protein, human; D000970:Antineoplastic Agents; D000071187:Autophagy-Related Protein 5; D001549:Benzamides; D008869:Microtubule-Associated Proteins; D010879:Piperazines; D047428:Protein Kinase Inhibitors; D011743:Pyrimidines; D017382:Reactive Oxygen Species; D000068877:Imatinib Mesylate; D011505:Protein-Tyrosine Kinases; D016044:Fusion Proteins, bcr-abl