The search for novel parameters to predict the risk of relapse in breast cancer was conducted. Significant correlation between the risk of relapse and α-2A adrenergic receptor (ADRA2A) expression was revealed using public microarray datasets. This relationship was confirmed by validation on independent microarray dataset. It was found that when assessing the risk of BC relapse, the accuracy of prediction based solely on the expression of ADRA2A gene is close to that made using OncotypeDX and MammaPrint test systems. In this case, addition of only one or two supplemental prognostic markers (for instance, expression of SQLE gene or SQLE andDSCC1genes) to ADRA2A ensures the accuracy of prediction not inferior to reliability of these test systems.
The paper presents a formalized statement of the problem of selecting parameters and construction of a genomic classifier for medical test systemswith mathematical methods of machine learning without the use of biological and medical knowledge. A method is proposed to solve this problem. The results of testing the method using microarray datasets containing information on genome-wide transcriptome of the samples of estrogen positive breast tumors are discussed. Testing showed that the quality of classification provided by the constructed test system and implemented on the basis of assessments of expression of 12 genes is not inferior to the quality of classification carried out by such test systems as OncotypeDX and MammaPrint.
The hypoxic response critically depends on the rapid stabilization of the Hypoxia-Inducible Factor (HIF). In normoxic conditions, HIF-prolyl hydroxylases mark α-subunits of HIF for degradation, while the hypoxia results in stabilization of HIF-α. Oxyquinoline derivatives suppress the activity of HIF-prolyl hydroxylases, leading to the stabilization of HIF. Here we show that the 24 hour incubation of the trophoblast model choriocarcinoma cells BeWo b30 line with the oxyquinoline derivative leads to a decrease in the transepithelial electrical resistance (TEER) of the cell monolayer, while the permeability of the monolayer for the FITC-dextran (70 kDa) remains unchanged. These observations indicate that the overall barrier function remain preserved, while the structure of intercellular tight junctions may undergo remodeling. Using Affymetrix Human Transcriptome Array 2.0, we show that the treatment with oxyquinoline derivative lead to a decrease in the expression of claudines 6 and 7 (CLDN6, CLDN7), occludin (OCLN), contact adhesion molecule 3 (JAM3) and angiotomin-like protein 1 (AMOTL1), which possibly explain the observed changes in TEER.
Hypoxia of trophoblast cells is an important regulating factor in the process of normal placenta development. However, the effect of hypoxia on the placenta in a number of pathological conditions, such as preeclampsia, leads to impaired cellular functions. A oxyquinoline derivative is capable of inhibiting HIF-prolyl hydroxylases, thereby stabilizing the transcription complex of HIF-1 and activating the cell response to hypoxia. BeWo b30 human choriocarcinoma cells are used to model trophoblast, which forms the basis for placenta barrier. Oxyquinoline effect leads both to an increased expression of a number of the genes that form the core response to hypoxia, and upregulated expression of NOS3, PDK1, and BNIP3 genes and downregulated expression of the PPARGC1B gene. This indicates the activation of mechanisms of metabolic cell reprogramming aimed at reducing oxygen consumption by reducing the number of mitochondria and switching from aerobic glucose metabolism to anaerobic. Possible applications of the obtained results is under discussion.
We studied the expression of peroxiredoxin genes (PRDX1, PRDX2, PRDX3, and PRDX6) in human erythroleukemia K652, human breast carcinoma MCF-7, and human ovarian carcinoma SKOV-3 cells during cisplatin resistance development. It was found that drug resistance formation was accompanied by a significant increase in the expression of PRDX1, PRDX2, PRDX3, PRDX6 genes in all cancer cell strains, which confirms the important contribution of redox-dependent mechanisms into the development of cisplatin resistance of cancer cells.