Effects of IL-18 gene transfection on the immunobiological characteristics of mouse ovarian cancer cell line OVHM

Objective To investigate the effects of IL-18 gene transfection on the immunobiological characteristics of mouse ovarian cancer cell line OVHM, such as the mRNA and protein expressions of IL-18, the concentration of IL-18 in the supernatant from OVHM, and the ability of inducing IFN-γ from murine splenocytes, in order to discuss the preliminary value of IL-18 gene transfection for treatment of ovarian cancer. Methods The OVHM cells were transfected with a retrovirus encoding IL-18 gene named as OVHM/IL-18, with the wild OVHM and the OVHM transfected with empty vector (OVHM/LXSN) as controls. The mRNA and protein expressions of IL-18 in three groups of OVHM were detected by RT-PCR and immunocytochemical staining, respectively. The concentration of IL-18 in supernatants of OVHM cells and the induced IFN-γ from murine splenocytes were determined by ELISA. Results The mRNA and protein expressions of IL-18 were detected only in OVHM/IL-18, not in wild OVHM or OVHM/LXSN. OVHM/-18 could secrete IL-18, which was reached the peak (138.25 pg/mL ± 12.36 pg/mL) after culture for 24 h, and then decreased gradually; IL-18 was not detected in the supernatants from both wild OVHM and OVHM/LXSN. The supernatant of OVHM/IL-18 induced more IFN-γ from murine splenocytes than that of other two similar groups of cells (33.84 pg/mL±2.36 pg/mL, 18.80 pg/mL±1.06 pg/mL, 18.43 pg/mL±2.64 pg/mL, respectively, P0.01). Conclusion IL-18 gene transfection elevates the mRNA expression of IL-18 and the release of produced protein from OVHM, and induces IFN-γ generated from immunocytes through increasing IL-18 in OVHM. So, IL-18 gene transfection should apply in inhibiting tumor growth and accelerating tumor regression through correcting the lower expressive state of IL-18 in OVHM and inducing the anti-tumor effects of IL-18.