[Serological diagnosis of tumors: methods of marker's search].

This review describes the most popular methods of search for serological markers of tumors that are used in clinical setting, provided with comparison of their efficiency.

[Enteric alpha defensin 5 is secreted into the blood stream by colon tumors].

It was demonstrated that enteric alpha-defensin 5 is undetectable in five blood serum samples of healthy donors, whereas its processed form is present in two out of five serum samples of colon cancer patients. Obtained results open a possibility of serological diagnosis of colon tumors in high risk cancer patients.

[A new construct of dna reporter for immuno-PCR].

A new construct of DNA reporter has been designed for protein quantification by immuno-PCR. It has been shown that amplification efficiency of a reporter that contains a fragment of human adenovirus 2 flanked by homoprimer sequences is much higher vs. standard PCR format based on use of two different primers. Application of a new construct and its homoprimer-based detection opens a way to a significant increase in the immuno-PCR sensitivity and the efficiency of single molecule PCR.

[Structure and function of enteric alpha defensins in norm and pathology].

This review summarizes currently available data on enteric alpha defensins structure, their functions in the innate and adaptive immunity systems and the role in development of intestinal illnesses.

[Identification of proteins overexpressed in malignant gastric tumors: comparison of the results of 2-De and bioinformatics 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.

[Identification of protein markers for serum diagnosis of cancer based on microRNA expression profiling].

A new algorithm has been developed for bioinformatics search of putative serum markers of cancer, which includes: 1) identification of microRNAs that are most often and most significantly overexpressed in tumors; 2) selection of mRNA targets regulated by microRNAs; 3) identification of mRNA targets encoding secreted proteins; 4) comparative analysis of mRNA transcription levels in normal and tumor tissues. Application of the algorithm led to discovery of seven putative serum markers of colon cancer: ADAMTS14, ANGPT2, CCL7, DEFA5, MMP11, MMP14, and PLAU. Experiments demonstrated that production of two out of seven proteins (MMP14 and DEFA5) is significantly increased in colon tumors vs. normal samples.

[Comparison of 2D analysis and bioinformatics search efficiency for colon cancer marker identification].

Modification of 2D analysis protocol was developed, based on preliminary removal of major cellular proteins by extraction with buffer saline and elimination of high molecular weight proteins by gel filtration. This approach allowed identification of 12 proteins with increased expression levels in tumors versus normal tissues. Increase in expression levels of the eight proteins in colon tumors was discovered for the first time. We performed comparison of marker search efficiency by 2D analysis and SAGE in a control panel of 19 putative colon cancer markers, discovered by us previously and at the same time independently identified by other authors. Results of 2D analysis of control panel completely coincided with published data, as compared to search in SAGE database, which allowed identification of only one third of markers.

[Proteomic expression analysis of human colorectal cancer: of soluble overexpressed proteins].

Colon cancer is one of the leading causes of cancer deaths in developed countries due to the absence of tumor specific markers for early diagnosis of the disease, providing adequate sensitivity. Search for diagnostic markers of various types of cancer by proteomic approaches has been limited by large differences in protein centration. We used preliminary extraction of major cellular proteins by 0.2 M sodium chloride in presence of nonionic detergent NP-40 in order to raise the sensitivity of the 2D PAGE detection of low-abundant soluble proteins, some of which may penetrate in blood circulation during carcinogenesis. Application of this procedure prior to 2D comparative analysis of proteomes of normal tissues and matched colon cancer specimens led to selection of ten proteins, which are frequently overexpressed in colon adenocarcinomas. Mass-spectrometric identification of selected proteins led to discovery of two novel protein markers of colon tumors--TAF9 and CISH. Low level of CISH expression in various tissues suggests that it is a novel prospective marker for diagnosis of colon cancer.