Cell-Based Gene Therapy Potentiates Rejection of Syngeneic Tumors.(Brief Article)

2001 JAN 31 - (NewsRx.com & NewsRx.net) -- Cytotoxic T lymphocytes (CTL) epitopes shared by many cancer types may be potential therapeutic anticancer targets, researchers in Argentina report.

"Cell-based gene therapy after cytokine gene transfer is being investigated for autologous and allogeneic vaccination in cancer therapy," wrote S. Adris and colleagues, University Buenos Aires. "Here we show that mice vaccinated with 3-5x10(6) interleukin 12 (IL-12) gene-transduced CT26 colon cancer cells developed a long-lasting antitumor immune memory able to reject not only parental cells but also syngeneic, LM3 mammary, and MCE fibrosarcoma tumorigenic cells."

Adris et al. published their study in the journal Cancer Research ("Mice vaccination with interleukin 12-transduced colon cancer cells potentiates rejection of syngeneic non-organ-related tumor cells," Cancer Res, December 1, 2000;60(23):6696-6703).

In contrast, the researchers observed that mice vaccinated with 0.5-1x10(6) CT26 cells transduced with pBabe neo IL-12 retrovirus cells (CT26-IL12) were only able to reject parental cells and not other syngeneic tumor cells. They noted an increase in the total circulating levels of immunoglobulin G2a (IgG2a) as well as a clear shift toward a systemic Th1 response in vaccinated mice regardless of the amount of injected CT26-IL12 cells they were given. Conversely, there was a strong increase in anti-CT26-specific IgG2a levels only when 3-5x10(6) CT26-IL12 cells were used to vaccinate the mice.

Extending the study, the researchers vaccinated immunocompetent mice with 3-5x10(6) CT26-IL12 cells. The vaccinated mice developed nodules local to the injection site which grew for only a few days before ceasing to develop further. Examination of the nodules showed that they were composed mainly of blood ...