Norcantharidin combined with diamminedichloroplatinum inhibits tumor growth and cancerometastasis of hepatic carcinoma in murine.

AIM: Norcantharidin (NCTD) has been used as a clinical antineoplastic drug in China for several years, and diamminedichloroplatinum is a valuable clinical cancer chemotherapy agent. Here, we tried to investigate the effects of NCTD plus diamminedichloroplatinum on hepatic carcinoma in murine. MATERIALS AND METHODS: In vivo and in vitro investigations on anticancer effects of the two drugs were individually made. RESULT: In vitro, the combination of the two drugs resulted in apparent apoptosis and cell proliferation inhibitions of H22 cancer cells. Meanwhile, their coadministration in vivo produced significant suppressions of tumor growth and cancerometastasis. Further, CD31 immunohistochemistry and matrigel tube formation assay demonstrated that angiogenesis was inhibited by NCTD plus diamminedichloroplatinum in vivo and in vitro, respectively. CONCLUSION: Based on the findings, we concluded that NCTD plus diamminedichloroplatinum may have an additive anticancer efficacy because the two drugs work in different ways, and thus, their combination had inhibited cancer cell proliferations and tumor angiogenesis more effectively than either of the compounds alone.

A vaccine targeting basic fibroblast growth factor elicits a protective immune response against murine melanoma.

Tumor growth and metastasis are closely related to angiogenesis. Basic fibroblast growth factor(bFGF) is an angiogenic factor, and up-regulated expression of bFGF plays a crucial role in the development and metastasis of melanoma. Therefore, in this study, we sought to achieve antitumor activity by immunity targeting bFGF which would inhibit tumor angiogenesis and simultaneously induce bFGF specific cytotoxic T lymphocytes to kill melanoma cells. A human bFGF protein was used as exogenous antigen, coupled with a saponin-liposome adjuvant formulation to enhance CTL response. The results showed that the immunity induced strong immune response and produced prominent anti-cancer activities. CD31 immunohistochemistry and alginate-encapsulated tumor cell assay displayed that tumor angiogenesis was effectively inhibited. Further, the higher production of IFN-γ and cytotoxic T lymphocyte killing assay suggested that the anti-cancer activities may mainly depend on cellular immune response, which could cause the inhibition of tumor angiogenesis and specific killing of tumor cells by bFGF-specific cytotoxic T lymphocytes. We concluded that immunotherapy targeting bFGF may be a prominent strategy for melanoma, and that the adjuvant formulation of saponin-liposome is very desirable in enhancing cytotoxic T lymphocytes response.

Astragalus Saponins and Liposome Constitute an Efficacious Adjuvant Formulation for Cancer Vaccines.

Cancer vaccines mostly aim to induce cytotoxic T lymphocytes (CTLs) against tumors. An appropriate adjuvant is of fundamental importance for inducing cellular immune response. Since the antigen in particulate form is substantially more immunogenic than soluble form antigen, it is beneficial to interact with antigen-presenting cells membrane to induce robust CD8+ T cell activation following vaccination. Based on previous research, we designed an adjuvant formulation by combining Astragalus saponins, cholesterol, and liposome to incorporate antigen into a particulate delivery system, so as to enhance cellular immune response. Meanwhile, angiogenesis contributes to tumor growth and metastasis, and basic fibroblast growth factor (bFGF) is involved in tumor angiogenesis. Therefore, using lipo-saponins adjuvant formulation and a human recombinant bFGF antigen protein, we tried to induce bFGF-specific CTL response to inhibit tumor angiogenesis to achieve antitumor activity. After five immunizations, the lipo-saponins/bFGF complex elicited robust antibody response and markedly higher amount of interferon-γ in BALB/c mice, resulting in superior antitumor activities. Decreased microvessel density in CD31 immunohistochemistry and the lysis of vascular endothelial cells by the T lymphocytes from the immunized mice indicated that the immunity inhibited the angiogenesis of tumors and further led to the inhibition of tumors. Our data suggest that the approach to construct adjuvant formulation between liposome and Astragalus saponins appeared highly desirable, and that Astragalus saponins may be utilized as a valuable additive for enhancing the effectiveness of vaccines and stimulating an appropriate immune response that can benefit tumor therapy.