Effects Of Immunomodulating Peptide (PGPIPN) On Immunity And Anti-ovarian Carcinoma In Mice

Objective To study the effects of immunomodulating peptide (PGPIPN) deriving fromβ-cacein on immunity and anti-ovarian carcinoma in mice.Method To investigate the effect of spleen T lymphocyte transformation impacted by PGPIPN at different concentrations with MTT method in vitro and in vivo. Twenty-four Balb/c-nu/nu (Balb/c Nude) mice were inoculated SKOV3 cells. After one week , 24 mice were randomly divided into control group, low dosage group, high dosage group and 5-fluorouracil (5-fu) group, which were given saline, the immunomodulating peptide at 0.4 and 0.8 mg/ml and 5-fluorouracil at 30mg/kg/d via celiac injection respectively. After administration of four weeks, the tumor weight, the tumor volume and tumor inhibitory rate were respectively calculated. The tumor tissue was observed by TUNEL. DNA ladder was observed by agarose gel electrophosesis. The Bcl-2 and Bax protein in tumor tissue were examined by immunohistochemistry and western blot. The levels of TNF-αand IFN-γwere detected by ELISA.Results 1. In vitro, LTs were markedly improved under together ConA at 5ug/ml with PGPIPN at different concentrations, compared with ConA group. However, PGPIPN didn't enhance spleen T lymphocyte transformation alone. In vivo, LT significantly improved in contrast with their control group, and there was a dose-dependent manner between PGPIPN and LT level. 2. Compared with the control group,the weights and volumes of the tumors were significantly decreased in the mice treated by PGPIPN. 3. Internucleosomal DNA fragments displayed the characteristic ladder-lane on electrophoresis in PGPIPN groups. 4. Compared with the control group,the apoptosis index (AI) were significantly increased in the treated mice by TUNEL staining. 5. The level of serum TNF-αwas significantly increased in high dosage group, but decreased in low dosage group compared with control. 6. Immunohistochemistry and western blot show that Bcl-2 expression was significant decreased, Bax experession were significantly increased, compared with the control group.Conclusion 1. PGPIPN can promote LT both in vivo and in vitro 2. PGPIPN has significant inhibitory effect on tumor growth of human ovarian cancer in nude mice, could induce apoptosis in ovarian cancer cells by regulating the expression of Bcl-2 and Bax.