Chromosomal proteins in transformed and neoplastic cells: a review

It is becoming increasingly apparent that chromosomal proteins (histones and nonhistone chromosomal proteins (NHCP) play an important role in dictating structural and functional properties of the eukaryotic genome. The histones, or basic chromosomal proteins, have been shown to function as repressors of DNA-dependent RNA synthesis as well as to be involved in packaging of the genome. Components of the NHCP also may be involved in the maintenance of genome structure, but additionally several lines of evidence suggest that among this complex and heterogeneous class of chromosomal proteins are macromolecules that are responsible for rendering defined genetic sequences transcribable. The structural and functional properties of chromosomal proteins have been the subject of several reviews and monographs and will therefore be discussed here only briefly. Understanding the manner in which chromosomal proteins interact with the information encoded in the nucleotide sequences of the DNA double helix undoubtedly will enhance our comprehension of a broad spectrum of normal biological processes, such as growth, development, differentiation, and maintenance of cellular phenotype. Furthermore, it is reasonable to anticipate that elucidation of the mechanisms by which gene readout is controlled will facilitate deciphering of the basis for the aberrations in gene expression that accompany disease processes such as neoplasia. The primary emphasis of this review will be the potential involvement of chromosomal proteins in the onset and maintenance of the neoplastic state.