Molecular constitution of breast but not other reproductive tissues is rich in growth promoting molecules: a possible link to highest incidence of tumor growths.

In the current study we tested if highest incidence of benign as well as cancer growths in breast tissue is due to constitutive molecular composition of this tissue. To delineate the molecular basis, we compared the expression of nine functional gene modules (total 578 genes) that regulate major positive growth and negative inhibitory signals in normal breast with two other reproductive tissues, ovary and uterus. We present data to demonstrate that breast tissues constitutively have very highly elevated levels of several growth promoting molecules and diminished levels of inhibitory molecules which may, in part, contribute for highest incidence of tumor growths in this tissue.