Failure of anti-tumor immunity inmammals - evolution of the hypothesis
I. Bubanovic1 and S. Najman2
1Department of Obstetrics and Gynecology, "Medica Center", Nis, Novosadska 1/c,
Nis, Serbia and Montenegro.
2Institute for Biology, University Medical School, Nis, Serbia and Montenegro.
Observations on the morphological and functional similarity between embryonic or
trophoblast tissues and tumors are very old. Over a period of time many investigators have
created different hypotheses on the origin of cancerogenesis or tumor efficiency in relation to
the host immune system. Some of these ideas have been rejected but many of them are still
current. A presumption of the inefficiency of anti-tumor immunity in mammals due to the high
similarity between trophoblast and embryonic cells to tumor cells is very real. The mechanisms
for the escape of tumors from the immune response are very similar to the mechanisms for the
escape of a fetoplacental unit from the maternal immune response. The similarity between these
two mechanisms is so great that any randomness must be banished. At the same time, an
incidence of malignant tumors and the types of more frequent tumors in non-mammalian
vertebrates is significantly different to that in mammals. Lastly, the mechanisms of anti-tumor
immunity in mammals are substantially different from the mechanisms of anti-tumor immunity
in other classes of vertebrates. These facts indicate that the immune system of mammals during
anti-tumor immune response is tricked by the similarity between tumor cells and trophoblast or
other placental cells. From this aspect, our conclusion is that anti-tumor immunity failure in
mammals can be defined as an immunoreproductive phenomenon, which is developed under the
evolutionary pressure of autoimmunity and reproductive effectiveness.
Key Words: Anti-tumor immunity, mammals, vertebrates, pregnancy, trophoblast.
[An article from Ivan Bubanovic (author)]