ABSTRACT
Histamine is one of the important mediators of many diseases such as hypersensitivity, gastric ulcer, and inflammation. It regulates the local immune response in tumor tissues by multiple mechanisms with ambivalent and double-faced effects, which have been uncovered partially by thorough molecular immunological analyses. Histamine has differential effects on the growth of tumor cell depending on selective reaction with its receptors, and on the secretion of variety of cytokines from local activated immune cells in a reciprocal manner by shifting TH1/TH2 polarization towards predominance of TH2. In this review, we summarized recent data suggesting that endogenous histamine should be an important correlated factor involved in bi-directional regulation both to tumor tissue and to infiltrating immune cells.