First Author | Takahashi Y | Year | 2013 |
Journal | Blood | Volume | 121 |
Issue | 9 | Pages | 1622-32 |
PubMed ID | 23287860 | Mgi Jnum | J:194771 |
Mgi Id | MGI:5474717 | Doi | 10.1182/blood-2012-10-459826 |
Citation | Takahashi Y, et al. (2013) Bif-1 haploinsufficiency promotes chromosomal instability and accelerates Myc-driven lymphomagenesis via suppression of mitophagy. Blood 121(9):1622-32 |
abstractText | Malignant transformation by oncogenes requires additional genetic/epigenetic changes to overcome enhanced susceptibility to apoptosis. In the present study, we report that Bif-1 (Sh3glb1), a gene encoding a membrane curvature-driving endophilin protein, is a haploinsufficient tumor suppressor that plays a key role in the prevention of chromosomal instability and suppresses the acquisition of apoptosis resistance during Myc-driven lymphomagenesis. Although a large portion of Bif-1-deficient mice harboring an Emu-Myc transgene displayed embryonic lethality, allelic loss of Bif-1 dramatically accelerated the onset of Myc-induced lymphoma. At the premalignant stage, hemizygous deletion of Bif-1 resulted in an increase in mitochondrial mass, accumulation of DNA damage, and up-regulation of the antiapoptotic protein Mcl-1. Consistently, allelic loss of Bif-1 suppressed the activation of caspase-3 in Myc-induced lymphoma cells. Moreover, we found that Bif-1 is indispensable for the autophagy-dependent clearance of damaged mitochondria (mitophagy), because loss of Bif-1 resulted in the accumulation of endoplasmic reticulum-associated immature autophagosomes and suppressed the maturation of autophagosomes. The results of the present study indicate that Bif-1 haploinsufficiency attenuates mitophagy and results in the promotion of chromosomal instability, which enables tumor cells to efficiently bypass the oncogenic/metabolic pressures for apoptosis. . |