Anti-angiogenic therapy against gastrointestinal tract cancers.

Gastrointestinal tract cancers constitute a group of highest morbidity both in and outside Japan, and the prognosis still remains unfavorable when the disease has progressed to the unresectable stage. Since the late 1990s, a novel category of anti-cancer drugs, 'molecular-targeted drugs', has become available, and angiogenesis has been considered as one of the most important molecular targets for antitumor therapy since it is essential for tumor growth. Anti-angiogenic therapy inhibits tumor angiogenesis and promotes apoptosis of existing tumor blood vessels, thereby intercepting the supply of oxygen and nutrition essential for tumor growth and metastasis.

[Development of HER2-specific humanized antibody Herceptin (trastuzumab)].

HER2 is a member of the human epidermal growth factor receptor family, possessing protein kinase activity in its cytoplasmic domain. There were evidences indicating that (1) amplification of HER2/neu gene and HER2 protein over-expression in tumor cells was observed in 25-30% of human breast cancer and (2) amplification of HER2/neu correlated with poor prognosis, including shorter disease-free and overall survival. These evidences suggested HER2 was a promising candidate for novel molecular targets of breast cancer therapy.