Adenoviral-mediated retinoblastoma 94 produces rapid telomere erosion, chromosomal crisis, and caspase-dependent apoptosis in bladder cancer and immortalized human urothelial cells but not in normal urothelial cells

Xinqiao Zhang, Asha S. Multani, Jain Hua Zhou, Jerry W. Shay, David McConkey, Li Dong, Chang Soo Kim, Charles J. Rosser, Sen Pathak, William F. Benedict

Research output: Contribution to journalArticle

Abstract

Retinoblastoma (RB)94, which lacks the NH2-terminal 112 amino acid residues of the full-length RB protein (RB110), is a more potent tumor and growth suppressor than RB110. In this study, Ad-RB94, but not Ad-RB110, produced marked growth inhibition, cytotoxicity, caspase-dependent apoptosis, and G2-M block in the human RB-negative, telomerase-positive bladder cancer cell line UM-UC14. This effect was completely inhibited by pre-treatment with caspase inhibitors (P < 0.0001). Similar results were seen in RB-positive and other RB-negative bladder cancer cell lines. Ad-RB94 produced rapid telomere length shortening and loss of telomere signal, which was associated with polyploidy and chromosomal aberrations (P < 0.001). Ad-RB94, however, showed no cytotoxicity to telomerase-negative human normal urothelium cells but was highly cytotoxic to telomerase-positive human E6 and E7 immortalized urothelial cells (P < 0.0001). In addition, telomerase-negative cells, which maintain their telomere length through an alternative lengthening of telomeres DNA recombination pathway, showed no cytotoxicity to RB94. These results suggest that the induction of rapid telomere erosion and chromosomal crisis by RB94 in telomerase-positive cancer and in telomerase-expressing immortalized human cells is a major factor in its selective and potent tumor suppression and cytotoxic activity. The lack of cytotoxicity to normal cells should also provide a high therapeutic index when used in gene therapy protocols for the treatment of bladder and other cancers.

Original languageEnglish (US)
Pages (from-to)760-765
Number of pages6
JournalCancer Research
Volume63
Issue number4
StatePublished - Feb 15 2003
Externally publishedYes

    Fingerprint

ASJC Scopus subject areas

  • Oncology
  • Cancer Research

Cite this