Immunotherapy in the search of antigens against stem cell cancer

There is evidence that supports the hypothesis of the existence of cancer stem cells (CSC), in which it postulates that these are responsible for the initiation, recurrence, metástasis, and resistance to cancer treatments, thus creating a need for therapies that specifically target these subpopulations of cells with stem cell characteristics in most malignant tumors with mixed cell phenotypes. Since its advent, immunotherapy has been used as an attractive approach due to the many shortcomings of conventional surgery, radiotherapy and chemotherapy in the treatment of cancer. Within tumor subsets neoplastically transformed cells demonstrate surface expression of molecules that are not typically present on the surface of the surrounding normal cells. In some cases, especially in malignant melanoma, the cytotoxic T lymphocytes (CTL) directed against tumor associated antigens (TAA) have been isolated to raise antibodies and somehow reduce the disease. The focus of cancer vaccine therapy is based on the idea that the immune system could mount a rejection response force against conglomerate neoplastically transformed cells. However, due to the low immunogenicity of TAA, down-regulation of MHC molecules, the lack of expression of appropriate co-stimulatory molecule, cytokine secretion inmunoinhibitorias etc., they rarely met expectations. This is why new markers that are not only safe and allow immunotherapy directed against CSC are now being sought, but also tumor eradication could be achieved with the combination of many therapies in order to have an efficient outcome in the treatment of this disease currently affecting the world.