Recombinant adenovirus encoding H-ras ribozyme induces apoptosis in laryngeal cancer cells through caspase- and mitochondria-dependent pathways

Chih Hung Wang, Li Jen Tsai, Yeou Ping Tsao, Jer Tsong Hsieh, Wei Wen Chien, Ching Len Liao, Hsing Won Wang, Hsiao Sheng Liu, Show Li Chen

Research output: Contribution to journalArticle

17 Citations (Scopus)

Abstract

Previously, we designed a ribozyme that targets the H-ras oncogene at the 12th codon mutation site (Chang et al., 1997). Ribozymes have antisense molecule and site-specific ribonuclease potential. In this study, an adenoviral vector was used to transduce the H-ras ribozyme into laryngeal cancer cells (HEp-2). This served to downregulate the H-ras gene expression in which this ribozyme performed antisense activity due to HEp-2 cells containing wild-type alleles in the 12th H-ras codon. Together, our data demonstrated that the recombinant adenovirus encoding H-ras ribozyme can be broadly regarded as a cytotoxic gene therapy in laryngeal cancer cells regardless of containing wild-type or mutant ras gene. In addition, the mechanism through which the H-ras ribozyme inhibited tumor growth was apoptosis and involved both caspase- and mitochondria-mediated pathways. The activators caspase-8 and -9 as well as the effector caspase-3 in the induction phase of apoptosis and the substrate PARP of caspase-3 in the execution phase were activated 48 h following the H-ras ribozyme treatment. Mitochondrial events characterized by the production of superoxide anion and the release of cytochrome c started at 24 h. Mitochondrial transmembrane potential loss occurred 48 h after the ribozyme treatment. However, Bcl-2 delayed cytochrome c release to the cytosol, but it could not protect the apoptosis effect, suggesting that cytochrome c release from mitochondria may not play a role in H-ras ribozyme-induced apoptosis.

Original languageEnglish
Pages (from-to)805-814
Number of pages10
JournalBiochemical and Biophysical Research Communications
Volume298
Issue number5
DOIs
Publication statusPublished - 2002
Externally publishedYes

    Fingerprint

Keywords

  • Apoptosis
  • Caspase
  • H-ras
  • Mitochondria

ASJC Scopus subject areas

  • Biochemistry
  • Biophysics
  • Molecular Biology

Cite this