Background & objective: Lidamycin (LDM, C-1027), an antitumor antibiotic containing a chromophore of enediyne structure, shows markedly cytotoxicities against cancer in vitro and in vivo. This study was to explore inhibitory effect of LDM on orthotopic transplanted tumors and hepatic metastasis of colon carcinoma 26 (C26) in mice.
Methods: A series of mice C26 models, including subcutaneous transplantation, orthotopic transplantation in cecum subserosa, intra-hepatic transplantation, and hepatic metastases after intra-splenic transplantation, were prepared and received intravenous injection of LDM 72 h after transplantation. Inhibitory rates of tumor growth and hepatic metastasis were calculated. LEICA QWINV3 image analysis system was used to determine the area of metastatic lesions in histopathologic sections.
Results: LDM at 0.025, 0.05, and 0.1 mg/kg inhibited the growth of subcutaneous tumors by 64.8%, 78.2%, and 94.2%, orthotopic tumors by 57.5%, 71.5%, and 93.0%, intra-hepatic tumors by 74.5%, 82.3%, and 92.8%, and intra-splenic tumors by 9.2%, 25.8%, and 70.2%, respectively. Determined by the numbers of metastatic nodules, LDM at 0.025, 0.05, and 0.1 mg/kg inhibited hepatic metastases from intra-splenic transplantation by 34.6%, 50.7%, and 76.3%, and larger metastatic lesions (> 2 mm) by 56.6%, 56.7%, and 90.8%, respectively. Evaluated by image analysis of metastatic lesions, LDM at 0.1 mg/kg inhibited hepatic metastases by 71.2%.
Conclusion: LDM can inhibit growths of subcutaneous, orthotopic, and intra-hepatic transplanted tumors and hepatic metastases of murine colon carcinoma 26.