Search

Comparison of protein expression in intestinal and diffuse stomach tumors by 2D gel electrophoresis led to identification of three proteins (SOD2, S100A6, and TXN), which are overexpressed in tumors as compared to normal controls. It was shown, that overexpression of proteins SOD2 and TXN occurs much more frequently in diffuse tumors than in intestinal ones. A control panel of eleven proteins overexpressed in stomach tumors has been selected based on the data of comparative 2D analysis described in the literature. Bioinformatics search for mRNAs encoding proteins from the control panel in Oncomine database (which contains the results of determination of mRNA transcription level in tumor vs. normal samples) demonstrated the coincidence of proteomic and transcriptomic data for seven out of 11 proteins.

A modified method of proteome comparative analysis based on preliminary removal of cell structural proteins by extraction using salt buffer and subsequent separation of extracts by two-dimensional gel electrophoresis was developed. Identification of differentially expressed proteins by mass spectrometry has revealed three proteins with noticeably increased level of synthesis in most samples of papillary thyroid tumors compared to normal tissues. An increase in ubiquitin content was found for the first time. Oncomarker search efficiencies by two-dimensional gel electrophoresis and bioinformatic search were compared.

Modern proteomic techniques make it possible to identify numerous changes in protein expression in tumor in comparison to normal tissues. Despite the wide application of proteomics in current studies, identification of proteins with stable concentration differences in normal and cancer cells remains rather difficult. The current study was directed to the search of new potential protein colorectal cancer markers using comparative proteomics of protein extracts obtained from primary tumors and adjacent normal tissues. This widespread neoplasm is characterized by lack of evident symptoms at early stages of cancerogenesis. It is highly important to develop fast and sensitive methods of molecular diagnostics. We studied paired cancerous and normal clinical tissue samples from 11 patients with colorectal adenocarcinomas by comparative 2-D PAGE and MALDI-TOF mass-spectrometry identification. Sixteen proteins with stable differential expression were selected and identified, including 13 overexpressed and 3 downregulated proteins. In summary, we describe the discovery overexpression of GPD1 and RRBP1 proteins and lack of expression for HNRNPH1 and SERPINB6 proteins which are new candidate biomarkers of colon cancer.

modified method of proteome comparative analysis based on preliminary removal of cell structural proteins by extraction using salt buffer and subsequent separation of extracts by two-dimensional gel electrophoresis was developed. Identification of differentially expressed proteins by mass spectrometry has revealed three proteins with noticeably increased level of synthesis in most samples of papillary thyroid tumors compared to normal tissues. An increase in ubiquitin content was found for the first time. Oncomarker search efficiencies by two-dimensional gel electrophoresis and bioinformatic search were compared. [ABSTRACT FROM AUTHOR]