Dataset Information

HACE1 is a tumor suppressor gene candidate in natural killer cell neoplasms.

ABSTRACT: HACE1 is an E3 ubiquitin ligase located in 6q21, the genomic region frequently deleted in natural killer (NK) cell malignancies. Here, we report HACE1 as a candidate tumor suppressor gene silenced through a combination of deletion and cytosine phosphate guanine island hypermethylation. We detected deletion of HACE1 in malignant NK cell lines (6 of 9, 67%) and primary biopsies (5 of 15, 33%) by quantitative PCR, with most of the specimen showing cytosine phosphate guanine island hypermethylation in the remaining allele, leading to low mRNA transcription. The ectopic expression of HACE1 in an HACE1-null NK cell line led to apoptosis and G2/M cell cycle arrest. Moreover, HACE1 expression was up-regulated in IL-2-activated normal NK cells and NK cells cocultured with an engineered NK cell target, K562 Clone 9.mbIL21, suggesting its role in the regulation of NK cell homeostasis. In conclusion, HACE1 is another potent tumor suppressor gene located within the 6q21 region, and loss of function of multiple tumor suppressor genes within 6q21 may be a critical determinant of NK cell lymphomagenesis.

SUBMITTER: Kucuk C

PROVIDER: S-EPMC3532710 | biostudies-literature | 2013 Jan

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

HACE1 is a tumor suppressor gene candidate in natural killer cell neoplasms.

Küçük Can C Hu Xiaozhou X Iqbal Javeed J Gaulard Philippe P Klinkebiel David D Cornish Adam A Dave Bhavana J BJ Chan Wing C WC

The American journal of pathology 20121109 1

HACE1 is an E3 ubiquitin ligase located in 6q21, the genomic region frequently deleted in natural killer (NK) cell malignancies. Here, we report HACE1 as a candidate tumor suppressor gene silenced through a combination of deletion and cytosine phosphate guanine island hypermethylation. We detected deletion of HACE1 in malignant NK cell lines (6 of 9, 67%) and primary biopsies (5 of 15, 33%) by quantitative PCR, with most of the specimen showing cytosine phosphate guanine island hypermethylation ...[more]

PMID: 23142381

Similar Datasets

Project description:Cellular transformation is associated with altered glutamine (Gln) metabolism. Tumor cells utilize Gln in the tricarboxylic acid (TCA) cycle to maintain sufficient pools of biosynthetic precursors to support rapid growth and proliferation. However, Gln metabolism also generates NADPH, and Gln-derived glutamate is used for synthesis of glutathione (GSH). As both NADPH and GSH are antioxidants, Gln may also contribute to redox balance in transformed cells. The Hace1 E3 ligase is a tumor suppressor inactivated in diverse human cancers. Hace1 targets the Rac1 GTPase for degradation at Rac1-dependent NADPH oxidase complexes, blocking superoxide generation by the latter. Consequently, loss of Hace1 increases reactive oxygen species (ROS) levels in vitro and in vivo. Given the link between Hace1 loss and increased ROS, we investigated whether genetic inactivation of Hace1 alters Gln metabolism. We demonstrate that mouse embryonic fibroblasts (MEFs) derived from Hace1(-/-) mice are highly sensitive to Gln withdrawal, leading to enhanced cell death compared with wild-type (wt) MEFs, and Gln depletion or chemical inhibition of Gln uptake blocks soft agar colony formation by Hace1(-/-) MEFs. Hace1(-/-) MEFs exhibit increased Gln uptake and ammonia secretion, and metabolic labeling using (13)C-Gln revealed that Hace1 loss increases incorporation of Gln carbons into the TCA cycle intermediates. Gln starvation markedly increases ROS levels in Hace1(-/-) but not in wt MEFs, and treatment with the antioxidant N-acetyl cysteine or the TCA cycle intermediate oxaloacetate efficiently rescues Gln starvation-induced ROS elevation and cell death in Hace1(-/-) MEFs. Finally, Gln starvation increases superoxide levels in Hace1(-/-) MEFs, and NADPH oxidase inhibitors block the induction of superoxide and cell death by Gln starvation. Together, these results suggest that increased ROS production due to Hace1 loss leads to Gln addiction as a mechanism to cope with increased ROS-induced oxidative stress.

Dataset Information

HACE1 is a tumor suppressor gene candidate in natural killer cell neoplasms.

Publications

HACE1 is a tumor suppressor gene candidate in natural killer cell neoplasms.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets