Antitumoral effect of interleukin-12-secreting fibroblasts in a mouse model of ovarian cancer: Implications for the use of ovarian cancer biopsy-derived fibroblasts as a vehicle for regional gene therapy

Abstract

Fibroblasts can easily be cultured from human solid ovarian tumor biopsies and are readily transfected using retroviral vectors. To test the feasibility of using these cells as a vehicle for regional, intraperitoneal (i.p.) ovarian cancer gene therapy, we first examined the behavior of murine fibroblasts transduced with the neo R marker gene and injected i.p. in syngeneic mice. We found that these fibroblasts were not invasive and formed clusters preferentially attached to the pancreatic and hepatic mesentery, where they survived for at least 30 days and continued to express neo R . We subsequently assessed the effect of regional delivery of murine interleukin-12 (mIL-12)-secreting fibroblasts in a syngeneic immunocompetent mouse model of ovarian cancer (ID8). ID8 ovarian tumor cells were injected i.p. into one flank. Our results show a survival of 88% at 120 days postinjection of animals treated with mIL-12-secreting fibroblasts i.p. in the other flank on the same day as injection of tumor cells. At that time, all animals coinoculated with ID8 cells and unmodified fibroblasts had been or needed to be culled because of advanced neoplastic disease (P Ͻ 10 Ϫ5 , log-rank test). Furthermore, animals treated with mIL-12-secreting fibroblasts had a statistically significant decrease in tumor burden, as measured by diaphragm weight, relative to mock-treated groups (P ϭ .0032, H-test). Our histological data show evidence for both immunological and anti-angiogenic mechanisms being implicated in this antitumoral effect. In addition, no signs of IL-12-induced toxicity were observed in any of the tissue sections analyzed. Taken together, our findings suggest that ovarian tumor biopsy-derived fibroblasts are a safe and efficacious vehicle for i.p. delivery of IL-12 as a regional secondary treatment for minimal residual disease of ovarian cancer. Cancer Gene Therapy (2000) 7, 707-720

Immune killing activity of lymphocytes on Hela cells expressing interleukin-12 in vitro

“…Sanches used IL-12 to transfect fibroblasts, obtaining stable expression of IL-12, and then IL-12-secreting fibroblasts were injected intraperitoneal into a mouse model of ovarian cancer (ID80). As a result, animals treated with mIL-12-secreting fibroblasts had a significant decrease in tumor burden [6] . Tasaki inoculated Colon26/IL-12 cells into syngeneic immunocompetent mice [7] .…”

Phase-I clinical trial of IL-12 plasmid/lipopolymer complexes for the treatment of recurrent ovarian cancer

“…15,16 Administration of recombinant IL-12 (rIL-12) or IL-12-transduced fibroblasts or dendritic cells in ovarian cancer mouse models has been shown to increase IFN-g concentrations, induce differentiation and proliferation of cytolytic immune cells, inhibit tumor growth and improve animal survival. [17][18][19][20][21][22] In ovarian cancer patients, exposure of blood or peritoneal lymphocytes to autologous tumors resulted in increased cytolytic activity of the lymphocytes. 23 Intraperitoneal (IP) treatment of patients with peritoneal carcinomatosis originating from gastrointestinal malignancies, mesothelioma, Mullerian carcinoma and ovarian carcinoma resulted in favorable immunological responses, including peritoneal tumor cell apoptosis, decreased tumor cell expression of basic fibroblast and vascular endothelial growth factor, and high levels of immunocytokines in the blood and peritoneal fluid (PF).…”

Angiogenesis meets immunology: Cytokine gene therapy of cancer

“…These goals lied behind the initial studies of insertion of cytokine genes into somatic cells (Bubenik et al, 1988;Tepper et al, 1989). In these and subsequent studies, transfer of normal or transformed cells engineered to release IL-2, IL4, IL-12 or IFN-c (Cavallo et al, 1992;Fearon et al, 1990;Kim et al, 1993;Lotze et al, 1994;Sanches et al, 2000;Shawler et al, 1995;Tahara et al, 1994), and several other cytokines (Forni et al, 1995) into the tumor microenvironment led to local recruitment of inflammatory cells that directly or indirectly can destroy a fraction of tumor cells, thereby releasing tumor antigens. Although cytokines can recruit different types of hematopoietic cells with different kinetics (Musiani et al, 1997), the outcome is usually similar and consists of tumor-specific immune activation and development of immune resistance against the subsequent challenge by parental tumor cells.…”