The oncoprotein HBXIP suppresses gluconeogenesis through modulating PCK1 to enhance the growth of hepatoma cells
CANCER LETTERS
Authors: Shi, Hui; Fang, Runping; Li, Yinghui; Li, Leilei; Zhang, Weiying; Wang, Huawei; Chen, Fuquan; Zhang, Shuqin; Zhang, Xiaodong; Ye, Lihong
Abstract
Hepatitis B X-interacting protein (HBXIP) as an oncoprotein plays crucial roles in the development of cancer, involving glucose metabolism reprogramming. In this study, we are interested in whether the oncoprotein HBXIP is involved in the modulation of gluconeogenesis in liver cancer. Here, we showed that the expression level of phosphoenolpyruvate carboxykinase (PCK1), a key enzyme of gluconeogenesis, was lower in clinical hepatocellular carcinoma (HCC) tissues than that in normal tissues. Mechanistically, HBXIP inhibited the expression of PCK1 through down-regulating transcription factor FOXO1 in hepatoma cells, and up-regulated miR-135a targeting the 3'UTR of FOXO1 mRNA in the cells. In addition, HBXIP increased the phosphorylation levels of FOXO1 protein by activating PI3K/Akt pathway, leading to the export of FOXO1 from nucleus to cytoplasm. Strikingly, over-expression of PCK1 could abolish the HBXIP-promoted growth of hepatoma cells in vitro and in vivo. Thus, we conclude that the oncoprotein HBXIP is able to depress the gluconeogenesis through suppressing PCK1 to promote hepatocarcinogenesis, involving miR-135a/FOXO1 axis and PI3K/Aktip-FOXO1 pathway. Our finding provides new insights into the mechanism by which oncoprotein HBXIP modulates glucose metabolism reprogramming in HCC. (C) 2016 Elsevier Ireland Ltd. All rights reserved.
Common alleles in candidate susceptibility genes associated with risk and development of epithelial ovarian cancer
INTERNATIONAL JOURNAL OF CANCER
Authors: Notaridou, Maria; Quaye, Lydia; Dafou, Dimitra; Jones, Chris; Song, Honglin; Hogdall, Estrid; Kjaer, Susanne K.; Christensen, Lise; Hogdall, Claus; Blaakaer, Jan; McGuire, Valerie; Wu, Anna H.; Van den Berg, David J.; Pike, Malcolm C.; Gentry-Maharaj, Aleksandra; Wozniak, Eva; Sher, Tanya; Jacobs, Ian J.; Tyrer, Jonathan; Schildkraut, Joellen M.; Moorman, Patricia G.; Iversen, Edwin S.; Jakubowska, Anna; Medrek, Krzysztof; Lubinski, Jan; Ness, Roberta B.; Moysich, Kirsten B.; Lurie, Galina; Wilkens, Lynne R.; Carney, Michael E.; Wang-Gohrke, Shan; Doherty, Jennifer A.; Rossing, Mary Anne; Beckmann, Matthias W.; Thiel, Falk C.; Ekici, Arif B.; Chen, Xiaoqing; Beesley, Jonathan; Gronwald, Jacek; Fasching, Peter A.; Chang-Claude, Jenny; Goodman, Marc T.; Chenevix-Trench, Georgia; Berchuck, Andrew; Pearce, C. Leigh; Whittemore, Alice S.; Menon, Usha; Pharoah, Paul D. P.; Gayther, Simon A.; Ramus, Susan J.
Abstract
Common germline genetic variation in the population is associated with susceptibility to epithelial ovarian cancer. Microcell-mediated chromosome transfer and expression microarray analysis identified nine genes associated with functional suppression of tumorogenicity in ovarian cancer cell lines; AIFM2, AKTIP, AXIN2, CASP5, FILIP1L, RBBP8, RGC32, RUVBL1 and STAG3. Sixty-three tagging single nucleotide polymorphisms (tSNPs) in these genes were genotyped in 1,799 invasive ovarian cancer cases and 3,045 controls to look for associations with disease risk. Two SNPs in RUVBL1, rs13063604 and rs7650365, were associated with increased risk of serous ovarian cancer [HetOR = 1.42 (1.15-1.74) and the HomOR = 1.63 (1.10-1.42), p-trend = 0.0002] and [HetOR = 0.97 (0.80-1.17), HomOR = 0.74 (0.58-0.93), p-trend = 0.009], respectively. We genotyped rs13063604 and rs7650365 in an additional 4,590 cases and 6,031 controls from ten sites from the United States, Europe and Australia; however, neither SNP was significant in Stage 2. We also evaluated the potential role of tSNPs in these nine genes in ovarian cancer development by testing for allele-specific loss of heterozygosity (LOH) in 286 primary ovarian tumours. We found frequent LOH for tSNPs in AXIN2, AKTIP and RGC32 (64, 46 and 34%, respectively) and one SNP, rs1637001, in STAG3 showed significant allele-specific LOH with loss of the common allele in 94% of informative tumours (p = 0.015). Array comparative genomic hybridisation indicated that this nonrandom allelic imbalance was due to amplification of the rare allele. In conclusion, we show evidence for the involvement of a common allele of STAG3 in the development of epithelial ovarian cancer.