CURRENT UNDERSTANDING OF THE MOLECULAR MECHANISMS IN ONCOGENESIS OF GASTROINTESTINAL STROMAL TUMORS

Abstract

The association of genetic driver changes in gastrointestinal stromal tumors (GIST) with clinical implications is the most studied aspect in all solid tumors. Genotyping of particular exons c-KIT and PDGFRA included in the standard practice of diagnosis and treatment of GIST. The review analyzes the current understanding of the molecular-genetic mechanisms and markers that underlie the GIST profiling. Of particular interest are wild-type tumors of c-KIT and PDGFRA, in which activating mutations of the RAS, BRAF and EGFR oncogenes are found, associated with the early stages of disease progression. The data of studies of genetic and epigenetic changes in GIST, which revealed the prognostic value of inactivation of CDKN2A and p53, deletions of 22q, 1p and 15q, CpG hypermethylation are presented. New factors that determine a high risk of progression of GISTs are described: inactivation of dystrophin, DNA hypomethylation, increased expression of miRNAs and HOTAIR. The progress achieved in understanding the molecular mechanisms of GISTs give the opportunity of developing and effectively applying new therapeutic approaches, expanding the range of molecular genetic markers that determine patient surveillance.