Molecular Diagnostics of Oncological Disease: Prospects for the Development of a Reference Material for the HER2 gene Content

Abstract

Cancer is the leading cause of death in the world. The development of oncopathology is closely related to various changes in the genetic material that occur in malignantly transformed cells. Medical decision-making requires a clear differentiation between normal and pathological indicators, which are, among other things, the results of application of quantitative methods in laboratory medicine. Studies of DNA isolated from a patient’s biological material, identification and measurement of the content of nucleotide sequences acting as oncopathology biomarkers allow to solve the problems of determining the genetic prerequisites for cancer, its early diagnosis, determining the treatment strategy, monitoring, and confirming the patient’s cure.The purpose of this research is to develop the main approaches to the design of DNA reference materials (RMs) for metrological support of molecular diagnostics of oncopathology through the example of the RM for the HER2 gene sequence content in the human genome, with the value of «the number of copies of the DNA sequence» which is metrologically traceable to the natural SI unit «one».In the course of the research, a technique for measuring the HER2 gene amplification (the number of copies of the gene sequence per genome) was developed based on the use of the digital PCR method (dPCR). Comparability of measurement results for the method developed by the authors, and the results obtained using a commercial kit by the MLPA method on samples of human biological material is shown.Five permanent cell lines obtained from the CUC «Vertebrate Cell Culture Collection» were characterized in relation to the copy number ratios of HER2 gene sequence and CEP17 and RPPH1 genes sequences. A cell line with the HER2 gene amplification was identified. The results obtained will be used to create the RM for the copy number ratio of the HER2 gene sequences and the RPPH1 and CEP17 gene sequences. Creation of matrix DNA RMs based on human cell cultures certified using dPCR will allow transferring the unit of copy numbers of the DNA sequence to calibrators included in medical devices, thereby ensuring the required reliability and comparability of measurement results in the laboratory diagnostics of oncopathology, as well as the possibility of calibrating routine methods of DNA diagnostics and intralaboratory quality control.