In:
Cancer Research, American Association for Cancer Research (AACR), Vol. 76, No. 14_Supplement ( 2016-07-15), p. LB-310-LB-310
Abstract:
Background & Aims: Liver is a major metabolic organ, yet the detailed metabolic alterations driving hepatocellular carcinoma (HCC) remain elusive. The rapid growing nature of HCC results in oxygen deprivation or hypoxia in regions of tumors with insufficient blood supply. Hypoxia unbalances the electron flow through the electron transport chain (ETC) resulting in reactive oxygen species (ROS) accumulation. Here we aim at delineating the mechanisms by which HCC evades oxidative stress. Methods: We performed transcriptome sequencing to study the gene expression profile in both HCC patients and HCC cell line. The mRNA expression of 100 paired HCC and corresponding non-tumorous tissues were analyzed. Stable RNAi knockdown by shRNA and genetic knockout by TALEN were established in HCC cells for functional characterization. Results: We demonstrated that HCC cells specifically utilized the mitochondrial protein NADH dehydrogenase (ubiquinone) 1 alpha subcomplex 4-like 2 gene (NDUFA4L2), in the complex I of the ETC, to survive hypoxia. NDUFA4L2 was drastically over-expressed in human HCC and closely associated with poor clinical outcomes in HCC patients. We confirmed that NDUFA4L2 was regulated by HIF-1α in HCC cells. Inactivation of HIF-1α/NDUFA4L2 in different HCC cell lines increased mitochondrial activity and oxygen consumption, resulting in ROS accumulation and ROS-mediated apoptosis in HCC cells. Knockdown of NDUFA4L2 markedly suppressed HCC growth and metastasis in vitro and in vivo. In addition, HIF inhibitors, digoxin and sorafenib, significantly suppressed growth of tumors that expressed high level of NDUFA4L2 in orthotopic HCC model. Conclusions: Our results have unprecedentedly uncovered the clinical relevance and oncogenic roles of NDUFA4L2 in HCC. Citation Format: Robin Kit-Ho Lai, Irix Ming-Jing Xu, David Kung-Chun Chiu, Aki Pui-Wah Tse, Larry Lai Wei, Cheuk-Ting Law, Derek Lee, Chun-Ming Wong, Maria Pik Wong, Irene Oi-Lin Ng, Carmen Chak Lui Wong. NADH dehydrogenase (ubiquinone) 1 alpha subcomplex 4-like 2 (NDUFA4L2) reduces oxidative stress to promote hepatocellular carcinoma. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr LB-310.
Type of Medium:
Online Resource
ISSN:
0008-5472
,
1538-7445
DOI:
10.1158/1538-7445.AM2016-LB-310
Language:
English
Publisher:
American Association for Cancer Research (AACR)
Publication Date:
2016
detail.hit.zdb_id:
2036785-5
detail.hit.zdb_id:
1432-1
detail.hit.zdb_id:
410466-3
