Nuclear matrix: application to diagnosis of cancer and role in transcription and modulation of chromatin structure

The nuclear matrix i s involved in the processing of the genetic information and in the organization of chromatin. In recent years we have come to appreciate the organization of functional domains within the nucleus (e .g . , transcript domains, RNA processing s i tes , s i tes of replication). The nuclear matrix is the foundation from which this organization is built, providing a scaffold upon which nuclear processes such as DNA replication and transcription occur. Chromatin is arranged into loop domains through the attachment of matrix associated regions (MARs) at the base of the loop to nuclear matrix proteins. Considering the role of the nuclear matrix in the organization and processing of the genetic information, it is not surprising to f ind that nuclear matrix proteins are informative in distinguishing cell types and disease states. For example, nuclear matrix proteins informative in the diagnosis of cancer, including breast cancer have been identif ied. Typical ly nuclear matrices are obtained fol lowing the salt extract ion of nuclease-digested nuclei . However, recent studies show that cisplatin preferentially crosslinks MAR DNA to nuclear matrix proteins in s i tu , providing a complimentary method to identify informative nuclear matrix proteins.