P15 - a new tumor suppressor gene

In addition to the tumor suppressor genes such as Rb and p53, it: has been found that some molecules of the same class named CKI (cyclin-dependent kin ase inhibitor) also play an important role in the inhibition of tumorigenes is and the tumor progression. In the KIP and INK4 families of CKIs, p15 sha res extensive homology with p16. Findings in many tumors and their cell lin es show that the inactivation of p15 (deletion, mutation, rearrangement, et c.) is very frequent, and inactive p15 is involved in the progress of some tumors. These studies provide evidence that the p15 is a new tumor suppress or gene. Furthermore, the research on the molecular mechanism of p15 in reg ulation of cell proliferation shows that p15 can inhibit the growth of some kinds of tumor cells, and p15 is the mediator of TGF-beta-induced cell arr est. Investigations on p15 in cell differentiation suggest that increased p 15 is related to the change of malignant phenotype. These results supply cl ues for further interpretation about the molecular mechanism of cell cycle control and cell tumorigenesis. And they may provide theoretical and experi mental basis for application of p15 to clinical therapy of tumors.