ABSTRACT
OBJECTIVE: To investigate the antitumor efficacy of anti-gelatinases dFv-LDP and its enediyne-energized fusion protein dFv-LDP-AE on human fibrosarcoma HT-1080 cancer cells. METHODS: Western blot was used to analyze the expression level of gelatinases in different cancer cell lines. The inhibitory effects of fusion protein dFv-LDP and its enediyne-energized fusion protein dFv-LDP-AE on HT-1080 were determined by MTT assay. The binding capability of fusion protein dFv-LDP with HT-1080 was detected by ELISA and immunofluorescence. FACS was used to analyze the cell cycle arrest by dFv-LDP, dFv-LDP-AE or their combination on HT-1080 cells. The anti-metastasis effects of dFv-LDP, dFv-LDP-AE or their combination on the experimental lung metastasis model established by HT-1080Luc via tail vein injection were also evaluated in this study. RESULTS: Expression level of gelatinases was higher in HT-1080 cells as compared to that of other cancer cell lines. The fusion protein dFv-LDP showed well binding capability with HT-1080 cells as determined by ELISA and immunofluorescence. The enediyne-energized fusion protein dFv-LDP-AE displayed extremely inhibitory effect on proliferation of HT-1080. Results of FACS indicated that the combination of dFv-LDP with dFv-LDP-AE could not further increase the G2/M proportion on cell cycle arrest. However, in vivo experiment as examined using the experimental lung metastasis model established via HT-1080Luc tail veil injection, the metastasis foci in group of fusion protein dFv-LDP (10 mg·g-1) was 55.8% compared to that of control group (P<0.01). The metastasis foci in group of dFv-LDP-AE at dosage of 0.4 and 0.6 mg·g-1 were 41.4% and 25.1% respectively compared to that of dFv-LDP 10 mg·g-1 group (P<0.01). The combination of dFv-LDP (10 mg·g-1) with dFv-LDP-AE (0.4 or 0.6 mg·g-1) showed an additive decrease of metastasis foci number in the lung of athymic mice, which were 20.3% (P<0.05, compared with dFv-LDP-AE at 0.4 mg·g-1) and 13.1% (P<0.05, compared with dFv-LDP-AE at 0.6 mg·g-1) respectively. CONCLUSION: The combination of dFv-LDP with its enediyne-energized fusion protein dFv-LDP-AE would intensify the anti-metastasis effect on experimental lung metastasis model as established via tail vein injection of HT-1080Luc cells.