HOMEPRODUCTSSERVICESCOMPANYCONTACTFAQResearchDictionaryPharmaMobileSign Up FREE or Login

Fragile gene product, Fhit, in oxidative and replicative stress responses.

Abstract
Though the fragile histidine triad gene product, Fhit, was discovered and characterized as a tumor suppressor 13 years ago, its sequence, structure, and cellular location did not provide clues to aid discovery of its mechanisms of suppression. Recently, using chemical cross-linkers and immunoprecipitation, a Fhit protein complex was identified that includes Hsp60 and Hsp10 which may mediate Fhit stability and mitochondrial localization, where Fhit binds and stabilizes ferredoxin reductase (Fdxr); when Fdxr is overexpressed, it can lead to production of reactive oxygen species (ROS) that induce apoptosis. Cancer cells expressing endogenous or exogenous Fhit, when exposed to H(2)O(2), an oxidative stress, produce higher levels of apoptosis-inducing ROS than matched, Fhit-negative cells; the Fhit-negative cancer cells survive, carrying DNA damage. In addition to this mitochondrial function, Fhit-overexpression in cancer cells exposed to replicative stress-inducing agents leads to enhanced caspase 3 activation and apoptosis, due to defective Chk1 activation. Thus, damage to the fragile FHIT locus leads to reduced expression of Fhit protein, and makes a two-pronged contribution to development of preneoplastic clonal expansion: (1) absence or reduction of Fhit leads to reduced expression of Fdxr and reduced ROS-induced apoptosis; (2) cells that escape ROS- or replicative stress-induced apoptosis can carry misrepaired DNA damage. The aberrant DNA damage response checkpoint in Fhit-deficient preneoplasias and cancers may make these lesions targets for inhibitors of proteins such as Parp1 and Chk1 with important roles in checkpoint responses, as observed for BRCA1-deficient cancer cells that also exhibit DNA damage repair deficiencies.
AuthorsHiroshi Okumura, Hideshi Ishii, Flavia Pichiorri, Carlo M Croce, Masaki Mori, Kay Huebner
JournalCancer science (Cancer Sci) Vol. 100 Issue 7 Pg. 1145-50 (Jul 2009) ISSN: 1349-7006 [Electronic] England
PMID19486340 (Publication Type: Journal Article, Review)
Chemical References
  • Neoplasm Proteins
  • fragile histidine triad protein
  • Acid Anhydride Hydrolases
Topics
  • Acid Anhydride Hydrolases (genetics, physiology)
  • Animals
  • DNA Replication
  • Humans
  • Neoplasm Proteins (genetics, physiology)
  • Oxidative Stress (genetics)

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 network!


Choose Username:
Email:
Password:
Verify Password: