Efficient inhibition of ovarian cancer by recombinant CXC chemokine ligand 10 delivered by novel biodegradable cationic heparin-polyethyleneimine nanogels

Abstract

Currently, great interest is focused on the antineoplastic effects of CXC chemokine ligand 10 (IP-10/CXCL10). IP-10 has shown significant antitumor and anti-metastatic properties via immunological, antiangiogenic and anti-neoplastic mechanisms. However, very few studies on the antitumor activity of IP-10 in human ovarian cancer have been reported. The use of polymeric nanoparticles to deliver functional genes intraperitoneally holds much promise as an effective therapy for ovarian cancer. In our study, a recombinant plasmid expressing IP-10 (pVITRO-IP-10) was constructed, and biodegradable cationic heparin- polyethyleneimine (HPEI) nanogels were prepared to deliver pVITRO-IP-10 into SKOV3 human ovarian cancer cells. Transfection efficiency was detected by expression profiling of green fluorescent protein. The expression of IP-10 was determined using RT-PCR and western blot analysis. In vitro, cell proliferation was evaluated by MTT assay. Apoptosis was examined by Hoechst33258/PI staining and flow cytometry assays. The effect on the inhibition of angiogenesis was evaluated by tube formation assay using human umbilical vein endothelial cells (HUVECs). Moreover, a SKOV3 intraperitoneal ovarian carcinomatosis model was established to investigate the antitumor activity of HPEI+pVITRO-IP-10 complexes in nude mice. Tumor weights were evaluated during the treatment course. Cell proliferation and apoptosis were evaluated by Ki-67 immunochemical staining and TUNEL assay, and the antiangiogenic effect of pVITRO-IP-10 was assessed by CD31 immunochemical staining and alginate-encapsulated tumor cell assay. pVITRO-IP-10 was efficiently transfected into SKOV3 cells by HPEI nanogels. Intraperitoneal administration of HPEI+pVITRO-IP-10 complexes led to effective growth inhibition of ovarian cancer, in which tumor weight decreased by ∼69.92% in the treatment group compared with that in the empty vector control group. Meanwhile, decreased cell proliferation, increased tumor cell apoptosis and reduction in angiogenesis were observed in the HPEI+pVITRO-IP-10 group compared with those in the control groups. These results indicated that HPEI nanogel delivery of pVITRO-IP-10 may be of value in the treatment against human ovarian cancer.