Hepatocellular Carcinoma‐Associated Protein TD26 Interacts and Enhances Sterol Regulatory Element‐Binding Protein 1 Activity to Promote Tumor Cell Proliferation and Growth

Hepatology ◽  
2018 ◽  
Vol 68 (5) ◽  
pp. 1833-1850 ◽  
Author(s):  
Chenchen Wang ◽  
Ying Tong ◽  
Yankai Wen ◽  
Jie Cai ◽  
Han Guo ◽  
...  
2010 ◽  
Vol 429 (2) ◽  
pp. 347-357 ◽  
Author(s):  
Kenji Ishimoto ◽  
Keisuke Tachibana ◽  
Ikuko Hanano ◽  
Daisuke Yamasaki ◽  
Hiroki Nakamura ◽  
...  

FDPS (farnesyl diphosphate synthase) catalyses the formation of farnesyl diphosphate, a key intermediate in the synthesis of cholesterol and isoprenylated cellular metabolites. FDPS is also the molecular target of nitrogen-containing bisphosphonates, which are used as bone-antiresorptive drugs in various disorders. In the present study, we characterized the sterol-response element and NF-Y (nuclear factor Y)-binding site in the human FDPS promoter. Using a luciferase assay, electrophoretic mobility-shift assay and chromatin immunoprecipitation assay, we demonstrated that these elements are responsible for the transcription of the FDPS gene, and that its transcriptional activation is mediated by SREBP-2 (sterol-regulatory-element-binding protein 2) and NF-Y. We also investigated whether sterol-mediated FDPS expression is involved in the cell proliferation induced by zoledronic acid, an FDPS inhibitor. We show that the SREBP-2- and NF-Y-mediated regulation of FDPS gene transcription modulates cell proliferation. These results suggest that SREBP-2 and NF-Y are required to trigger cell proliferation through the induction of FDPS expression and that the pharmacological action of zoledronic acid is involved in this pathway.


2001 ◽  
Vol 71 (3) ◽  
pp. 116-125
Author(s):  
Norina Basa ◽  
Daniela Lazar ◽  
Remus Cornea ◽  
Sorina Taban ◽  
Melania Ardelean ◽  
...  

Alteration of β-catenin expression is involved in the development and evolution of hepatocellular carcinoma (HCC); β-catenin is able to influence tumor cell proliferation. We analyzed the immunohistochemical (IHC) expression of β-catenin on a group of 32 patients diagnosed with HCC using the anti-β-catenin monoclonal antibody (clone E247). We correlated the expression of β-catenin with the proliferation index of Ki-67 (PI Ki-67), the mitotic index (MI) and other clinical and pathological features. We observed an altered β-catenin expression in 58.38% of all HCC cases. This expression was insignificantly correlated with tumor size (]5 cm) (p = 0.683), histological grade G1-G2 (p = 0.307), vascular invasion (p = 0.299) and advanced pT stage (p = 0.453); we obtained a significantly higher MI in HCC with altered β-catenin expression (p = 0.018), as compared to HCC without overexpression (1.66 � 1.37) (p = 0.038) and a PI Ki-67 of 22.49 � 20.1 and 28.24 � 18.2, respectively in tumors with altered β-catenin expression with insignificant differences compared to HCC without overexpression (25.95 � 15.2) (p = 0.682 and p = 0.731, respectively). According to the results we obtained, aberrant β-catenin expression in HCC was correlated with a high mitotic index, therefore playing an important role in tumor progression by stimulating tumor cell proliferation; non-nuclear β-catenin overexpression can have a pathological significance in HCC, especially in cases of HCC associated with hepatitis B virus (HBV) infection.


1995 ◽  
Vol 270 (49) ◽  
pp. 29422-29427 ◽  
Author(s):  
Xianxin Hua ◽  
Juro Sakai ◽  
Ho Y. K. ◽  
Joseph L. Goldstein ◽  
Michael S. Brown

2009 ◽  
Vol 29 (17) ◽  
pp. 4864-4872 ◽  
Author(s):  
Seung-Soon Im ◽  
Linda E. Hammond ◽  
Leyla Yousef ◽  
Cherryl Nugas-Selby ◽  
Dong-Ju Shin ◽  
...  

ABSTRACT We generated a line of mice in which sterol regulatory element binding protein 1a (SREBP-1a) was specifically inactivated by insertional mutagenesis. Homozygous mutant mice were completely viable despite expressing SREBP-1a mRNA below 5% of normal, and there were minimal effects on expression of either SREBP-1c or -2. Microarray expression studies in liver, where SREBP-1a mRNA is 1/10 the level of the highly similar SREBP-1c, demonstrated that only a few genes were affected. The only downregulated genes directly linked to lipid metabolism were Srebf1 (which encodes SREBP-1) and Acacb (which encodes acetyl coenzyme A [acetyl-CoA] carboxylase 2 [ACC2], a critical regulator of fatty acyl-CoA partitioning between cytosol and mitochondria). ACC2 regulation is particularly important during food restriction. Similar to Acacb knockout mice, SREBP-1a-deficient mice have lower hepatic triglycerides and higher serum ketones during fasting than wild-type mice. SREBP-1a and -1c have identical DNA binding and dimerization domains; thus, the failure of the more abundant SREBP-1c to substitute for activating hepatic ACC2 must relate to more efficient recruitment of transcriptional coactivators to the more potent SREBP-1a activation domain. Our chromatin immunoprecipitation results support this hypothesis.


Sign in / Sign up

Export Citation Format

Share Document