The study of RNA markers in blood of patients with malignant tumors of gastrointestinal tract

In order to develop a diagnostic panel, mRNA levels of tumor marker genes have been evaluated in capillary blood of patients with various malignant tumors of the gastrointestinal tract (GIT) by means of the method of reverse transcription combined with real-time PCR with detection of reaction products using TaqMan probes. Use of small volumes of capillary blood did not decrease sensitivity of this method. RNA expression of telomerase (mhTERT), alpha-fetoprotein (mAFP), carcinoembryonic antigen (mCEA) and cytokeratin-20 (mCK-20) was higher in most patients with tumors. Blood of donors or non-oncological patients contained much lower (trace) amounts of the RNA markers. The RNA markers are characterized by reasonably high specificity and sensitivity acceptable for diagnostic application. The mhTERT marker was the most universal one and exhibited the highest specificity and sensitivity. Combined determination of several RNA markers increased sensitivity of this method. It is concluded that determination of RNA markers in small volumes of capillary blood may be used for screening, primary diagnostics, and postoperative monitoring.