HOMEPRODUCTSCOMPANYCONTACTFAQResearchDictionaryPharmaSign Up FREE or Login

Functional analysis of transactivation by mutants of hepatitis B virus X gene in human hepatocellular carcinoma.

Abstract
The X protein of the hepatitis B virus transactivates various cellular and viral promoters and enhancers. In this study, wild-type and mutants of the X gene, including the point mutations at codons 130 (AAG-->ATG, lysin-->methionine) and 131 (GTC-->ATC, valine-->isoleucine), commonly found in patients with human hepatocellular carcinoma (HCC), or deletions encompassing the same region, were cloned and inserted into expression vectors. Functional analysis of the mutants of the X gene was performed on the long terminal repeat of the Rous sarcoma virus in a transient transfection assay. A transactivating function was observed in the vector containing point mutations at codons 130 and 131 at the same level as that of wild-type X gene. Two constructs, each containing a different type of 8-nucleotide deletion mutant (codons 128-130 or 130-132,) dramatically lost their transactivating function. These findings suggest that the transactivating function is not necessarily associated with the development of HCC, and that not only transactivation by the X gene but also the mutation-enhanced oncogenic potential of the gene products could contribute to hepatocarcinogenesis.
AuthorsMasami Minemura, Yukihiro Shimizu, Katsuharu Hirano, Yasuhiro Nakayama, Yoshiharu Tokimitsu, Kazuto Tajiri, Kazuki Yamada, Feng Xue, Terumi Takahara, Akiharu Watanabe, Toshiro Sugiyama
JournalOncology reports (Oncol Rep) Vol. 14 Issue 2 Pg. 495-9 (Aug 2005) ISSN: 1021-335X [Print] Greece
PMID16012736 (Publication Type: Journal Article)
Chemical References
  • Trans-Activators
  • Viral Regulatory and Accessory Proteins
  • hepatitis B virus X protein
Topics
  • Animals
  • Avian Sarcoma Viruses (genetics)
  • Base Sequence
  • Carcinoma, Hepatocellular (genetics, pathology)
  • Cell Line, Tumor
  • Cell-Free System
  • Genetic Vectors (genetics)
  • Humans
  • Molecular Sequence Data
  • Mutation
  • Protein Biosynthesis (genetics)
  • Rabbits
  • Reticulocytes (metabolism)
  • Sequence Homology, Nucleic Acid
  • Trans-Activators (genetics)
  • Transcription, Genetic (genetics)
  • Transcriptional Activation (genetics)
  • Transfection
  • Viral Regulatory and Accessory Proteins

Join CureHunter, for free Research Interface BASIC access!

Take advantage of free CureHunter research engine access to explore the best drug and treatment options for any disease. Find out why thousands of doctors, pharma researchers and patient activists around the world use CureHunter every day.
Realize the full power of the drug-disease research graph!


Choose Username:
Email:
Password:
Verify Password:
Enter Code Shown: