Prohibitin 1 Regulates the H19-Igf2 Axis and Proliferation in Hepatocytes.
Prohibitin 1 (PHB1) is a mitochondrial chaperone that regulates cell growth. Phb1 knock-out mice exhibit liver injury and hepatocellular carcinoma (HCC). Phb1 knock-out livers show induction of tumor growth-associated genes, H19 and insulin-like growth factor 2 (Igf2). These genes are controlled by the imprinting control region (ICR) containing CCCTC-binding transcription factor (CTCF)-binding sites. Because Phb1 knock-out mice exhibited induction of H19 and Igf2, we hypothesized that PHB1-mediated regulation of the H19-Igf2 axis might control cell proliferation in normal hepatocytes. H19 and Igf2 were induced (8-20-fold) in 3-week-old Phb1 knock-out livers, in Phb1 siRNA-treated AML12 hepatocytes (2-fold), and HCC cell lines when compared with control. Phb1 knockdown lowered CTCF protein in AML12 by ∼30% when compared with control. CTCF overexpression lowered basal H19 and Igf2 expression by 30% and suppressed Phb1 knockdown-mediated induction of these genes. CTCF and PHB1 co-immunoprecipitated and co-localized on the ICR element, and Phb1 knockdown lowered CTCF ICR binding activity. The results suggest that PHB1 and CTCF cooperation may control the H19-Igf2 axis. Human HCC tissues with high levels of H19 and IGF2 exhibited a 40-50% reduction in PHB1 and CTCF expression and their ICR binding activity. Silencing Phb1 or overexpressing H19 in the mouse HCC cell line, SAMe-D, induced cell growth. Blocking H19 induction prevented Phb1 knockdown-mediated growth, whereas H19 overexpression had the reverse effect. Interestingly H19 silencing induced PHB1 expression. Taken together, our results demonstrate that the H19-Igf2 axis is negatively regulated by CTCF-PHB1 cooperation and that H19 is involved in modulating the growth-suppressive effect of PHB1 in the liver.
From the Division of Gastroenterology and Hepatology, Cedars-Sinai Medical Center, Los Angeles, California 90048.
Komal
K
Ramani
From the Division of Gastroenterology and Hepatology, Cedars-Sinai Medical Center, Los Angeles, California 90048.
Nirmala
N
Mavila
the Department of Nutritional Science and Food Management, the College of Health Science, Ewha Womans University, Seoul 03760, Korea, and.
Kwang Suk
KS
Ko
the CIC bioGUNE, Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (Ciberehd), Technology Park of Bizkaia, 48160 Derio, Bizkaia, Spain.
José M
JM
Mato
From the Division of Gastroenterology and Hepatology, Cedars-Sinai Medical Center, Los Angeles, California 90048, shelly.lu@cshs.org.
Shelly C
SC
Lu
D000818:Animals; D000076246:CCCTC-Binding Factor; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000502:physiology*; D022781:Hepatocytes / Q000166:cytology / Q000378:metabolism*; D006801:Humans; D007335:Insulin-Like Growth Factor II / Q000235:genetics / Q000378:metabolism*; D008099:Liver / Q000378:metabolism; D051379:Mice; D018345:Mice, Knockout; D000091402:Prohibitins; D062085:RNA, Long Noncoding / Q000235:genetics / Q000378:metabolism*; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism*; D020218:Response Elements; D015398:Signal Transduction / Q000502:physiology*
D000076246:CCCTC-Binding Factor; C000619697:CTCF protein, human; C000619698:Ctcf protein, mouse; C094335:H19 long non-coding RNA; C035170:IGF2 protein, human; C513121:IGF2 protein, mouse; C000717328:PHB protein, human; D000091402:Prohibitins; D062085:RNA, Long Noncoding; D012097:Repressor Proteins; D007335:Insulin-Like Growth Factor II
CCCTC-binding transcription factor; H19; Prohibitin 1; RNA; cell growth; cell proliferation; hepatocellular carcinoma; hepatocyte; imprinting control region; insulin-like growth factor 2
J Biochem. 2000 May;127(5):711-5
10788777
Apoptosis. 2015 Sep;20(9):1135-49
26091791
Oncogene. 2002 Dec 5;21(55):8388-96
12466959
Biochim Biophys Acta. 2011 Jun;1813(6):1137-43
21296110
Mol Cell Biol. 1999 Nov;19(11):7447-60
10523633
J Cell Mol Med. 2006 Apr-Jun;10(2):353-63
16796804
Oncogene. 2000 Dec 14;19(54):6376-85
11175353
Cancer Lett. 1997 Nov 11;119(2):143-8
9570364
J Hepatol. 2004 May;40(5):808-14
15094229
J Biol Chem. 2003 Nov 28;278(48):47853-61
14500729
EMBO J. 2000 Jun 1;19(11):2444-51
10835343
Hepatology. 2008 Jul;48(1):146-56
18537183
Hepatology. 2010 Dec;52(6):2096-108
20890892
Biochem Biophys Res Commun. 1989 Nov 15;164(3):1316-22
2480116
Sci Rep. 2013 Nov 04;3:3123
24185039
Int J Mol Sci. 2016 Mar 11;17 (3):356
26978351
PLoS One. 2007 Sep 05;2(9):e845
17786216
J Cell Physiol. 2014 Aug;229(8):998-1004
24347342
J Cell Physiol. 2015 May;230(5):1075-85
25294683
Proc Natl Acad Sci U S A. 2006 Jul 11;103(28):10684-9
16815976
Nature. 2000 May 25;405(6785):486-9
10839547
Mol Cell Biol. 2002 Apr;22(8):2450-62
11909940
Hepatology. 2010 Nov;52(5):1621-31
20815019
J Endocrinol. 1996 Jun;149(3):367-72
8691094
J Proteomics. 2012 Oct 22;75(18):5783-92
22951295
Mol Biol Cell. 2005 Jan;16(1):248-59
15525670