Purpose: It is well known that hypoxic milieu is the primary cancer environment. Therefore, tumor hypoxia is considered to be a potential therapeutic target. In the present study, we investigated the antitumor and antimetastatic effect of hypoxic cell radiosensitizer, TX-1877 on xenograft model of rectal cancer.
Methods: Nude mice bearing subcutaneously or orthotopically implanted human colon cancer cell lines HCT-116 and HT-29 were treated with TX-1877, irradiation or TX-1877 with irradiation. Tumor volume, survival, expression of matrix metalloproteinase (MMP)-2, MMP-7, MMP-9 and urokinase-type plasminogen activator (uPA) and incidence of lymph node metastasis were evaluated in treatment versus control group.
Results: In subcutaneous model, tumor treated with TX-1877 and irradiation showed significant reductions in volume (P < 0.05 vs. control, TX-1877 or irradiation group). Quantitative real-time reverse transcription-PCR and immunohistochemical analysis revealed that TX-1877 significantly inhibited expression of the MMP-9 and uPA. These treatments also inhibited the para-aortic lymph node metastasis, however, did not prolong the survival in orthotopic model.
Conclusions: These data show that the treatment of TX-1877 with irradiation decreased growth of human rectal cancer and, furthermore, suppressed lymph node metastasis.