A variety of genetic constructs are disclosed that will find both in vitro and in vivo use in the area of tumor biology and cancer therapy. In particular, expression constructs are provided that contain a p16 encoding region and other regulatory elements necessary for the expression of a p16 transcript. One version of the expression construct is a replication-deficient adenoviral vector. Also provided are methods for the transformation of cell lines and the inhibition of cancer cell proliferation.