| Objective To study anti-ovarian carcinoma and its mechanism of immunomodulating peptide (PGPIPN) derived from cacein by model of nude mice taking human ovarian cancer(SKOV3).Methods Model of nude mice, taking human ovarian cancer (SKOV3), was made. Twenty-four BALB/cAnN-nu/nu(BALB/c Nude) and inbred strain mice were randomly divided into control group (NS), low dosage group(PGPIPN1), high dosage group (PGPIPN2) and 5-fluorouracil group (5-fu), which were respectively given saline, the immunomodulating peptide at 0.25 and 0.50 mg/ml, and 5-fluorouracil at 30mg/kg/d via celiac injection. After administration of five weeks , the tumor volume, the tumor weight, spleen weight, spleen index and tumor inhibitory rate were respectively calculated. The tissues of tumor were observed by Hematoxylin-eosin (HE) and flow cytometric assay (FCM). DNA ladder to assay the DNA degradation was observed by agarose gel electrophosesis. RT-PCR technique was used to investigate the mRNA contents of gene caspase-3/bcl-2. Furthermore, immunocytochemistry was used to examine the changes of their protein expression. The levels some hormones in serum were evaluated with radioimmunoassay.Results 1.Compared with the control group,the weights and volumes of the tumors were significantly reduced in the treated mice by PGPIPN. 2.the levels of serum IGF-1 in control group were significantly higher than in PGPIPN groups.3.The characteristic morphological changes of ovarian carcinoma apoptosis were observed by HE staining in PGPIPN groups. 4.Internucleosomal DNA fragments displayed the characteristic ladder-lane on electrophoresis in PGPIPN groups. 5.There were significantly apoptotic peaks on the Flow Cytometer' s graphs in PGPIPN groups. 6.The expression of caspase-3 gene also increased significantly, while the expression of BCL-2 gene decreased in PGPIPN groups.Conclusion 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 caspase-3 genes, and decreased the levels of IGF-1 in serum. |
