Targeted endostatin-cytosine deaminase fusion gene therapy plus 5-fluorocytosine suppresses ovarian tumor growth

Oncogene. 2013 Feb 28;32(9):1082-90. doi: 10.1038/onc.2012.134. Epub 2012 May 7.

Abstract

There are currently no effective therapies for cancer patients with advanced ovarian cancer, therefore developing an efficient and safe strategy is urgent. To ensure cancer-specific targeting, efficient delivery, and efficacy, we developed an ovarian cancer-specific construct (Survivin-VISA-hEndoyCD) composed of the cancer specific promoter survivin in a transgene amplification vector (VISA; VP16-GAL4-WPRE integrated systemic amplifier) to express a secreted human endostatin-yeast cytosine deaminase fusion protein (hEndoyCD) for advanced ovarian cancer treatment. hEndoyCD contains an endostatin domain that has tumor-targeting ability for anti-angiogenesis and a cytosine deaminase domain that converts the prodrug 5-fluorocytosine (5-FC) into the chemotherapeutic drug, 5-fluorouracil. Survivin-VISA-hEndoyCD was found to be highly specific, selectively express secreted hEndoyCD from ovarian cancer cells, and induce cancer-cell killing in vitro and in vivo in the presence of 5-FC without affecting normal cells. In addition, Survivin-VISA-hEndoyCD plus 5-FC showed strong synergistic effects in combination with cisplatin in ovarian cancer cell lines. Intraperitoneal (i.p.) treatment with Survivin-VISA-hEndoyCD coupled with liposome attenuated tumor growth and prolonged survival in mice bearing advanced ovarian tumors. Importantly, there was virtually no severe toxicity when hEndoyCD is expressed by Survivin-VISA plus 5-FC compared with CMV plus 5-FC. Thus, the current study demonstrates an effective cancer-targeted gene therapy that is worthy of development in clinical trials for treating advanced ovarian cancer.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Line, Tumor
  • Cytosine Deaminase / genetics
  • Endostatins / genetics
  • Female
  • Flucytosine / therapeutic use*
  • Gene Fusion*
  • Genetic Therapy / methods*
  • Humans
  • Mice
  • Ovarian Neoplasms / therapy*
  • Recombinant Fusion Proteins / genetics
  • Xenograft Model Antitumor Assays

Substances

  • Endostatins
  • Recombinant Fusion Proteins
  • Flucytosine
  • Cytosine Deaminase