Strategies for Tracking Immune Surveillance of Tumor Milieu during Angiogenesis

Life Sciences-Biotechnology

Abstract

Cancer is a multi-stage, multi-mechanistic, multifactorial complex process that has excessive potential for excessive proliferation  with no relation to the physiological  organ. Inherited genetic inclinations  contribute  extensively  to about 10 % of breast cancers and about 13 % of colon cancers incidences. In the industrialized countries, 7% of most cancer deaths result from viral infections; 4% from occupational  hazards; 2% from sunlight; 2% from air, water, and soil pollution; and less than 1% from diet and lifestyle. Formation of new blood vessels, angiogenesis, is elicited by tissue hypoxia and is essential for normal course of development  of every  tissue  and organ.  Angiogenesis  unequivocally  promotes  tumor  growth  and metastasis.  Tumors  exhibit different rates of pathological angiogenesis and involve not only abnormally proliferating cancer cells, but also various tumor- infiltrating  leukocytes  and stromal  cells.   Local milieu  of the cancers  polarizes  the leukocytes  to support  the tumor  growth further. Although conventional knowledge reveals that immune surveillance helps to suppress tumor development, unresolved immune mechanisms including chronic inflammation can promote growth and progression of tumors. In this review, we outline the immune cells and their derived factors, including immunosuppressive  and inflammatory cytokines that either can promote or inhibit cancer development,  and the role of tumor microenvironment  in this process of regulation.  In the present review, the role of T-lymphocytese, NK cells, antibody dependent cell cytotoxicity, tumor escape mechanisms are presented.