Proteomic analysis of the nuclear matrix in the early stages of rat liver carcinogenesis: identification of differentially expressed and MAR-binding proteins.
Tumor progression is characterized by definite changes in the protein composition of the nuclear matrix (NM). The interactions of chromatin with the NM occur via specific DNA sequences called MARs (matrix attachment regions). In the present study, we applied a proteomic approach along with a Southwestern assay to detect both differentially expressed and MAR-binding NM proteins, in persistent hepatocyte nodules (PHN) in respect with normal hepatocytes (NH). In PHN, the NM undergoes changes both in morphology and in protein composition. We detected over 500 protein spots in each two dimensional map and 44 spots were identified. Twenty-three proteins were differentially expressed; among these, 15 spots were under-expressed and 8 spots were over-expressed in PHN compared to NH. These changes were synchronous with several modifications in both NM morphology and the ability of NM proteins to bind nuclear RNA and/or DNA containing MARs sequences. In PHN, we observed a general decrease in the expression of the basic proteins that bound nuclear RNA and the over-expression of two species of Mw 135 kDa and 81 kDa and pI 6.7-7.0 and 6.2-7.4, respectively, which exclusively bind to MARs. These results suggest that the deregulated expression of these species might be related to large-scale chromatin reorganization observed in the process of carcinogenesis by modulating the interaction between MARs and the scaffold structure.
Barboro
Paola
P
Istituto Nazionale per la Ricerca sul Cancro, Largo Rosanna Benzi, 10-16132 Genova, Italy.
D'Arrigo
Cristina
C
Repaci
Erica
E
Bagnasco
Luca
L
Orecchia
Paola
P
Carnemolla
Barbara
B
Patrone
Eligio
E
Balbi
Cecilia
C
D000818:Animals; D015153:Blotting, Western; D018797:Cell Cycle Proteins; D015180:Electrophoresis, Gel, Two-Dimensional; D006360:Heat-Shock Proteins / Q000032:analysis / Q000378:metabolism; D034441:Heterogeneous-Nuclear Ribonucleoproteins / Q000032:analysis / Q000378:metabolism; D053531:Keratins, Type II / Q000032:analysis / Q000378:metabolism; D034882:Lamins / Q000032:analysis / Q000378:metabolism; D008113:Liver Neoplasms / Q000378:metabolism* / Q000473:pathology / Q000648:ultrastructure; D008297:Male; D036961:Matrix Attachment Region Binding Proteins / Q000032:analysis / Q000378:metabolism*; D008854:Microscopy, Electron; D015530:Nuclear Matrix / Q000737:chemistry / Q000378:metabolism* / Q000648:ultrastructure; D034521:Nuclear Matrix-Associated Proteins / Q000032:analysis / Q000378:metabolism*; D009687:Nuclear Proteins / Q000032:analysis / Q000378:metabolism; D011485:Protein Binding; D040901:Proteomics / Q000379:methods*; D015138:RNA, Nuclear / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000032:analysis / Q000378:metabolism; D051381:Rats; D011916:Rats, Inbred F344; D012263:Ribonucleosides / Q000737:chemistry / Q000378:metabolism; D053719:Tandem Mass Spectrometry / Q000379:methods; D013997:Time Factors; D014638:Vanadates / Q000737:chemistry / Q000378:metabolism
D018797:Cell Cycle Proteins; D006360:Heat-Shock Proteins; D034441:Heterogeneous-Nuclear Ribonucleoproteins; D053531:Keratins, Type II; D034882:Lamins; D036961:Matrix Attachment Region Binding Proteins; D034521:Nuclear Matrix-Associated Proteins; D009687:Nuclear Proteins; C489081:Numa1 protein, rat; D015138:RNA, Nuclear; D016601:RNA-Binding Proteins; D012263:Ribonucleosides; C057724:vanadyl ribonucleoside complex; D014638:Vanadates