Abstract
The inefficiency of the immune system to kill cancer cells leads to the disease. Like in pregnancy, oncofetal proteins counteract the immune attack. Alpha-fetoprotein is an immunosuppressive protein generated by the embryo and in insignificant amounts by adults. It delivers nutrients to embryo cells and to the monocytes that suppress both innate and adaptive immunity during pregnancy and cancer. The small subpopulation of suppressor monocytes and cancer cells absorb the alpha-fetoprotein-nutrient complex through the specific receptor that is mostly absent in normal adult cells. It comes out that suppressor monocytes are the main targets in cancer prophylactic or treatment, not cancer cells. By delivering toxins instead of nutrients alpha-fetoprotein kills suppressor monocytes canceling immune suppression, as well as killing cancer cells directly. It is the perfect synergy of the most powerful cancer immunotherapy with targeted chemotherapy. Alpha-fetoprotein chemical conjugates, as well as the complexes of this oncofetal protein with binding toxins, have shown promising results in cancer treatments. Oral porcine alpha-fetoprotein complexes with toxins can prevent and/or treat cancer, although their immunotherapy mechanism of action is undiscovered.