Objective: To study in series the p16 protein expression on the rat brain tumor induced transplacentally by ENU.
Methods: The p16 protein expression was determined with immuno-histochemistry stain on the offspring's brain at their 60, 90, 120, 150 days after birth.
Results: (1) p16 proteins were expressed in all of the brain samples in the 60-day group; occasionally negative in the 90-day group; partly expressed in the 120-day group; significantly less expressed in the 150-day group. (2) The rate of expression in the tissue around tumor was higher than that in the tumor. (3) The p16 protein was mainly orientated in the nuclear of cell and sporadically orientated in the cytoplasm.
Conclusion: (1) It shows the p16 protein expression decreases with the increase of tumor incidence in the rat brain, which accompanies the start and development of the induced tumor. So we speculate that the dysfunction of p16 gene is one of the factors related to tumor incidence in this animal model. (2) The p16 protein is mainly orientated in the nuclear of cell and sporadically orientated in the cytoplasm.