[Connexin 43 expression in human brain glial tumors]. / Ékspressiia konneksina 43 v glial'nykh opukholiakh golovnogo mozga cheloveka.

AIM: Тo conduct an immunohistochemical (IHC) study of the expression of connexin 43 in the samples of glial tumors of various grades: gemistocytic astrocytomas (Grade 2), oligodendrogliomas (Grade 2) and glioblastomas (Grade 4). MATERIAL AND METHODS: The material investigated was fragments of human brain glial tumors (grade 2 gemistocytic astrocytomas (n=2), grade 2 oligodendrogliomas (n=2), and grade 4 glioblastomas (n=14) and those of tumor-surrounding tissue (n=4). The material was fixed in 10% buffered formalin, dehydrated, and embedded in paraffin according to the standard technique. IHC studies of the slices applied primary rabbit polyclonal antibodies against connexin 43 ('Spring Bioscience', USA) and the Dako EnVision + Peroxidase (DAB) visualization system ('Dako', Denmark). After the immunohistochemical reaction, the cell nuclei were stained with Mayer's hematoxylin. RESULTS: Immunohistochemistry showed the changing pattern of connexin 43 expression as compared with intact tissue in the glial tumors. Instead of the fine-granular expression in the thin cellular processes in the neuropil, the tumors mainly displayed a coarse-grained cytoplasmic and even nuclear reaction. The morphology and localization of positive structures depended on the variant of an examined tumor. In addition, the most malignant brain gliomas generally exhibited a reduction in the expression of connexin 43, i.e. its quantity is inversely proportional to the degree of malignancy of the tumor. CONCLUSION: The low connexin 43 expression levels may reflect both a reduction in astroglial functional gap junctions and semicanals and a decrease in the amount of the protein itself that has independently antioncogenic properties. The observed cytoplasmic and nuclear expression of connexin 43 is most likely to be associated with the aberrant activity of a number of kinases, such as proto-oncogene tyrosine-kinase Src or protein kinase C (PKC).

[THE LONG NON-CODING RNA ASSOCIATED WITH CANCEROGENESIS: BIOLOGICAL SIGNIFICANCE AND PERSPECTIVES OF APPLICATION IN DIAGNOSTIC].

The last decade is characterized by development of such technologies as RNA-sequencing and biochips which resulted in discovery of new perspective biomarkersfor personalized diagnostic of cancer. Among them, the long non-coding RNA (IncRNA) are of special interest because according the recent studies they are positioned as important regulators of gene expression on epigenetic, transcription and post-transcription levels. The review considers the role of long non-coding RNA in cancerogenesis. The corresponding of their application in diagnostic is evaluated. A number of examples ofperspective diagnostic and prognostic markers. Their degree of implementation in oncological practice is discussed.