EXPRESSION PROFILE OF miR-145, -182, -21, -27a, -29b, and -34a IN BREAST CANCER PATIENTS OF YOUNG AGE.

BACKGROUND: Breast cancer (BC) in young women remains a significant public health concern. While progress has been made in understanding the etiology, diagnosis, and treatment of BC in this population, challenges persist. The identification and utilization of prognostic biomarkers offer valuable tools for tailoring treatment strategies and improving outcomes for BC patients. AIM: To evaluate the relationship between the expression of tumor-associated microRNAs and the clinical and pathological features of BC in young patients. MATERIALS AND METHODS: The work is based on the results of the examination and treatment of 50 women younger than 45 years with stage I-II BC. miR-145, -182, -21, -27a, -29b, and -34a expression in tumor samples was analyzed by the real-time reverse transcription polymerase chain reaction. RESULTS: Higher expression of miR-182, -21, and -29b and lower levels of miR-27a were associated with tumor stage in young BC patients. Patients without lymph node metastases (N0) had significantly higher levels of miR-182, -27a, and -34a and lower levels of miR-29b compared to N1 cases (p < 0.05). Expression of miR-145, -182, -21, -27a, and -29b was associated with molecular BC subtypes. CONCLUSION: Obtained results show that a high malignancy degree of BC in young women is associated with an increase in the miR-182, -21, -29b, and -34a expressions and a decrease in the miR-27a level in the tumor tissue, which indicates the prospects of the use of them for predicting the aggressiveness of the disease.

OPTIMIZATION OF EXPERIMENTAL MODEL SYSTEMS FOR EVALUATING RECIPROCAL INFLUENCE OF BIFIDOBACTERIUM ANIMALIS AND HUMAN BREAST CANCER CELLS IN VITRO.

BACKGROUND: The development of human breast cancer (BC) is known to be closely related to disturbances in the mammary gland microbiota. Bacteria of the genus Bifidobacterium are an important component of normal breast microbiota and exert antitumor activity. The molecular-biological mechanisms of interaction between BC cells and microbiota members remain poorly studied yet. The aim of this study was to develop and optimize an experimental model system for the co-cultivation of BC cells with Bifidobacterium animalis in vitro. MATERIALS AND METHODS: Human ВС cells of the MCF-7, T47D, and MDA-MB-231 lines, as well as live and heat-inactivated bacteria of Bifidobacterium animalis subsp. lactis (B. animalis) were used as research objects. The growth kinetics and viability of B. animalis in the presence of different ВС cell lines and without them were determined by both the turbidimetry method and seeding on an elective nutrient medium. Glucose consumption and lactate production by bifidobacteria were assessed by biochemical methods. The viability of BC cells was determined by a standard colorimetric method. RESULTS: The growth kinetics of B. animalis in the complete DMEM nutrient medium showed standard patterns. The indicators of glucose consumption and lactate production of B. animalis confirm its physiological metabolic activity under the growth conditions. The presence of BC cells in the model system did not affect the duration of the growth phases of the B. animalis cells' population but contributed to the increase in their counts. A significant decrease in the number of live BC cells of all studied lines was observed only after 48 h of co-cultivation with live B. animalis. To achieve similar suppression of the BC cell viability, 10-30-fold higher counts of heatinactivated bacteria were required compared to live ones. CONCLUSIONS: The optimal conditions for co-cultivation of human BC cells and living B. animalis cells in vitro have been identified.

FEATURES OF BREAST CANCER IN PATIENTS OF YOUNG AGE: SEARCH FOR DIAGNOSIS OPTIMIZATION AND PERSONALIZED TREATMENT.

The statistical data of the recent decades demonstrate a rapid growth of breast cancer (BCa) incidence and a tendency toward its increase especially in young women. In the structure of morbidity of women in the age group of 18-29 years, BCa ranks first and in the age range of 15-39 years, BCa is one of the leading causes of mortality. According to the data of the epidemiological and clinical studies, the young age is an independent unfavorable prognostic factor of BCa that is associated with an unfavorable prognosis and low survival rates and is considered an important predictor of the disease aggressiveness, a high risk of metastasis and recurrence. The variability of clinicopathological and molecular-biological features of BCa in patients of different age groups as well as the varying course of the disease and different responses to the therapy are mediated by many factors. The analysis of the literature data on the factors and mechanisms of BCa initiation in patients of different age groups demonstrates that the pathogen- esis of BCa depends not only on the molecular-genetic alterations but also on the metabolic disorders caused by the current social and household rhythm of life and nutrition peculiarities. All these factors affect both the general con- dition of the body and the formation of an aggressive microenvironment of the tumor lesion. The identified features of transcriptome and the differential gene expression give evidence of different regulations of the immune response and the metabolic processes in BCa patients of different age groups. Association between the high expression of the components of the stromal microenvironment and the inflammatory immune infiltrate as well as the increased vascu- larization of the tumor lesion has been found in BCa tissue of young patients. Proving the nature of the formation of the landscape comprising molecular-genetic, cytokine, and immune factors of the tumor microenvironment will undoubtedly contribute to our understanding of the mechanisms of tumor growth allowing for the development of algorithms for delineating the groups at high risk of tumor progression, which requires more careful monitoring and personalized treatment approach. Th s will be helpful in the development of innovative technologies for complex BCa treatment.

PATTERN OF MMP2 AND MMP9 EXPRESSION DEPENDS ON BREAST CANCER PATIENTS' AGE.

BACKGROUND: Despite the large number of studies devoted to the study of the features of tumor microenvironment in breast cancer (BCa), presently there is no consensus on the features of MMP-2 and MMP-9 expression in the tumor tissue of BCa patients depending on the age. The aim of the study was to investigate the relationship between MMP-2 and -9 expression at the protein and mRNA levels in BCa tissues and the clinical and pathological features of BCapatientsin different age groups. MATERIALS AND METHODS: The expression level of MMP-2 and -9in the BCa tissue of patients of two age groups (< 45 years and > 45 years) was studied using the bioinformatics method (UALCAN database), immunohistochemical method, and real-time PCR. RESULTS: It was established that a characteristic feature of BCa in young patients is the low level of MMP2 mRNA against the background of increased expression of this gelatinase at the protein level, as well as decreased expression of MMP9 at both the mRNA and protein levels. When analyzing the correlation of the gelatinase expression indices in BCa tissue of young patients, depending on the clinical and pathological features, a significantly lower level of MMP-2 expression was recorded in BCa cases of stage II compared to the indices of stage I cases. High expression of MMP-2 and -9 was recorded in BCa tissue in node-positive cases and the basal molecular BCa subtype. CONCLUSIONS: The identified relationship between the expression of the studied gelatinases and such indices of BCa malignancy as its stage, positive regional lymph node status, and the molecular BCa subtype in young patients indicates the need for further research of the features of the tumor microenvironment to predict the cancer aggressiveness.

FEATURES OF COL1A1 EXPRESSION IN BREAST CANCER TISSUE OF YOUNG PATIENTS.

BACKGROUND: In the last decades, the incidence of breast cancer (BCa) in young women has been increasing steadily. The quantitative indicators of expression of collagen, which play important role in stromal microenvironment, and their association with the age and survival rates of BCa patients have not been yet definitively clarified. AIM: To investigate the relationship between the COL1A1 gene expression at the mRNA and protein levels in BCa tissue and the clinicopatological features and survival rates of BCa patients of different age groups. MATERIALS AND METHODS: The study was conducted on the clinical material of 50 patients with stage I-III BCa. COL1A1 gene expression at the mRNA and protein levels in BCa tissue were studied using the real-time PCR and immunohistochemical methods, as well as the bioinformatic analysis (UALCAN and Kaplan - Meier Plotter databases). RESULTS: The bioinformatic analysis showed that BCa tissue is characterized by 6.0 times (p < 0.05) higher level of COL1A1 mRNA compared to normal breast tissue. The correlation of COL1A1 expression at the mRNA and protein levels with the molecular subtype of neoplasms was demonstrated. According to Kaplan - Meier Plotter database, a low level of expression of COL1A1 protein level in BCa tissue is associated with lower rates of relapse-free survival of patients. The ex vivo study of the clinical material revealed a decrease in COL1A1 protein expression in tumor tissue of young patients with BCa of T3 category (p < 0.0374), low differentiation grade (p < 0.0163) and basal molecular subtype (p < 0.0001). A correlation between the expression of COL1A1 at the mRNA and protein levels and the expression status of estrogen receptors (p < 0.0001) and progesterone receptors (p < 0.0040) was established. The relapse-free 3-year survival rate of young BCa patients is significantly lower in the presence of a low COL1A1 optical density index in the tumor tissue. CONCLUSIONS: The identified relationship between COL1A1 expression and such indicators of BCa malignancy as tumor size, differentiation grade, molecular subtype, receptor status, and the recurrencefree survival of patients indicates the prospects of its use to predict the aggressiveness of the BCa course in young patients.

EXPRESSION OF OSTEOPONTIN AND OSTEONECTIN IN BREAST AND PROSTATE CANCER CELLS WITH DIFFERENT SENSITIVITY TO DOXORUBICIN.

BACKGROUND: According to modern literature, osteopontin (OPN) and osteonectin (ON) are involved not only in the formation of the aggressive phenotype of malignantly transformed cells, but also in the realization of cytotoxic effects of some antitumor drugs. AIM: To study the changes of the expression of OPN and ON and their mRNAs (SPP1 and SPARC) upon exposure to doxorubicin (Dox) in breast cancer (BCa) and prostate cancer (PCa) cell lines with different sensitivity to Dox. MATERIALS AND METHODS: Cell lines of BCa (MCF-7 and MDA-MB-231) and PCa (LNCaP and DU-145) were cultured in the presence of Dox at IC30 concentrations for 24 h. OPN and ON levels were assessed by immunocytochemical (ICH) and Western blot analysis. SPP1 and SPARC mRNA levels were assessed by quantitative PCR. RESULTS: Dox treatment resulted in the significant decrease in the expression of both OPN and ON in MCF-7 and LNCaP cells. Similarly, Dox treatment downregulated both SPP1 and SPARC in MDA-MB-231 and DU-145 cells. Dox did not affect ON expression in MDA-MB-231 and DU-145 cells although the significant decrease in the level of SPARC mRNA has been evident. In contrast, no significant differences in SPP1 and SPARC mRNA levels were detected in LNCaP cells. CONCLUSION: The changes in the expression of OPN and ON proteins and their corresponding genes in BCa and PCa cells may be related to the intrinsic mechanisms of Dox effects in cells differing by malignant phenotype and Dox sensitivity.

HUMAN MICROBIOTA AND BREAST CANCER.

Breast cancer is the leading malignancy in women worldwide. To date, much is known about the molecular subtypes of these malignant neoplasms and the mechanisms of drug resistance. Significant success has been achieved in approaches to early diagnosis, which allows identifying the tumor process in the early stages of development. Recently, the study of the influence of the human body microbiota on cancer development and the effectiveness of treatment has become an actively developing field of research. This review presents an analysis of the literature data on this issue.

EXPRESSION OF MARKERS OF BONE TISSUE REMODELING IN BREAST CANCER AND PROSTATE CANCER CELLS IN VITRO.

The aim of the study was to compare the expression of markers of bone remodeling in vitro in breast cancer (BCa) cells and prostate cancer (PCa) cells varying in their malignancy phenotype. MATERIALS AND METHODS: The study was performed on human BCa cells (MCF-7 and MDA-MB-231 lines) and PCa cells (LNCaP and DU-145 lines). Expression levels of bone tissue remodeling proteins (osteopontin (OPN), osteonectin (ON) and bone morphogenetic protein 7 (BMP-7) were determined immunocytochemically. The mRNA levels of bone tissue remodeling proteins OPN (SPP1), ON (SPARC), BMP-7 (BMP7)) and miRNA-10b, -27a, -29b, -145, -146a were assessed by quantitative reverse transcription polymerase chain reaction. To search for miRNAs involved in the regulation of target genes, miRNet v. 2.0 resource was used. RESULTS: We have shown that highly malignant MDA-MB-231 cells are characterized by significantly higher expression of OPN and ON on the background of decreased SPARC and BMP7 mRNA expression. In highly malignant DU-145 cells, ON and SPP1, SPARC, and BMP7 mRNA expression was significantly higher compared with low malignant LNCaP cells. MDA-MB-231 line was characterized by significantly higher expression of miRNA-10b, -27a, -29b, -145 and -146a. In DU-145 cells, significantly lower levels of expression of miRNAs-27a and -145 against the background of increasing levels of miRNAs-29b and -146a were recorded. CONCLUSION: High malignancy phenotype of the BCa and PCa cells is characterized by high levels of expression of bone remodeling proteins, which may be caused by impaired regulation of their expression at the epigenetic level.

EVALUATION OF DIAGNOSTIC ALGORITHM BASED ON COLLAGEN ORGANIZATION PARAMETERS FOR BREAST TUMORS.

The changes in the quantitative parameters and spatial structure of collagen are considered a key diagnostic and prognostic factor associated with the development of many malignant neoplasms, including breast cancer (BCa). The aim of the work was to develop and test an algorithm for the assessment of collagen organization parameters as informative attributes associated with BCa for developing technology of machine learning and building an intelligent system of cancer diagnostics. MATERIALS AND METHODS: Tumor tissue samples of 5 patients with breast fibroadenomas and 20 patients with stage I-II BCa were studied. Collagen was identified histochemically by Mallory method. Photomicrographs of the studied preparations were obtained using a digital microscopy complex AxioScope A1. Morphometric studies were performed using the software CurveAlign v. 4.0. beta and ImageJ. RESULTS: The algorithm for determining the quantitative characteristics and spatial organization of the collagen matrix in tumor tissue samples has been developed and tested. We showed that collagen fibers in the BCa tissue are characterized by significantly lower values of length (p < 0.001) and width (p < 0.001) as well as higher values of straightness (p < 0.001) and angle (p < 0.05) compared to these in the fibroadenoma tissue. No significant difference was found in the density of collagen fibers in the tissue of benign and malignant neoplasms of the mammary gland. CONCLUSION: The algorithm allows assessing a wide range of parameters of collagen fibers in tumor tissue, including their spatial orientation and mutual arrangement, parametric characteristics and density of the three-dimensional fibrillar network.

BIOMAGNETISM OF DRUG-SENSITIVE AND DRUG-RESISTANT MALIGNANT TUMORS AFTER INJECTION OF FERROMAGNETIC NANOCOMPOSITE.

Magnetic signals emitted by living organisms, regardless of a biological species, are important biophysical indicators. The study of these indicators is very relevant and promising for the visualization of the tumor process and the development of technologies using artificial intelligence when it comes to malignant neoplasms, particularly resistant to chemotherapy. AIM: To measure magnetic signals from transplantable rat tumors and their counterparts resistant to cytostatics for evaluating the features of the accumulation of iron-containing nanocomposite Ferroplat. MATERIALS AND METHODS: Doxorubicin (Dox)-sensitive and Dox-resistant Walker-256 carcinosarcoma and cisplatin-sensitive and cisplatin-resistant Guerin's carcinoma transplanted in female Wistar rats were studied. The magnetism of tumors, liver and heart was determined using Superconductive Quantum Interference Device (SQUID) - magnetometry in a non-contact (13 mm over the tumor) way using specially designed computer programs. In a group of the experimental animals, a ferromagnetic nanocomposite (Ferroplat) was administered as a single intravenous injection and biomagnetism was assessed in 1 h. RESULTS: The magnetic signals coming from Dox-resistant Walker-256 carcinosarcoma in the exponential growth phase were significantly higher in comparison with sensitive tumor. Intravenous administration of Ferroplat increased biomagnetism by at least an order of magnitude, especially in resistant tumors. At the same time, the magnetic signals of the liver and heart were within the magnetic noise. CONCLUSION: The use of SQUID-magnetometry with ferromagnetic nanoparticles as a contrast agent is a promising approach for visualization of malignant neoplasms with varying sensitivity to chemotherapy.

Differential expression patterns of AIP, UCKL1, and PKN1 genes in breast cancer of different molecular subtypes.

BACKGROUND: Classification of breast cancer (BC) in the molecular subtypes had the enormous impact on the development of the individualized therapy. Nevertheless, there is a need for additional biomarkers that would help to refine molecular subtypes of BC and propose the therapeutic approach for each patient. AIM: To study differential expression patterns of AIP, UCKL1, and PKN1 genes in blood sera and tumor tissue of patients with BC of different molecular subtypes. MATERIALS AND METHODS: The total extracellular RNA was isolated from serum of 26 BC patients. cDNAs was synthesized and quantitative polymerase chain reaction was performed. Also, immunohistochemical studies of UCKL, AIP and PKN1 were performed on deparaffined tissue sections. The study was supplemented by a bioinformatic analysis of the publicly available databases. RESULTS: AIP and UCKL-1 extracellular mRNA levels were 100-1000-fold increased in blood sera of all BC patients, compared to the healthy donors. The highest levels were detected in the luminal A and HER2 (ERRB2) BC subtypes. The highest levels of PKN1 were detected blood sera of the patients with luminal B and basal subtypes; its expression levels were just 10-100-fold higher in BC samples compared to healthy donors. CONCLUSIONS: The UCKL1, AIP, PKN1 genes are overexpressed at the mRNA level in blood sera of BC patients compared to the sera of healthy individuals. Among three genes under study, only for the AIP gene, the pattern of extracellular mRNA expression in sera paralleled to protein expression in BC tissues of each specified molecular subtype.

Can SARS-CoV-2 change individual radiation sensitivity of the patients recovered from COVID-19? (experimental and theoretical background).

R.E. Kavetsky Institute of Experimental Pathology, Oncology and Radiobiology of the National Academy of Science of Ukraine has been studying the mechanisms and specificities of individual radiation sensitivity (IRS) formation in professionals who work in the field of ionizing radiation, cancer patients and representatives of other population groups. Our data based on the use of G2-test in in vitro irradiated blood lymphocytes in late G2-period of cell cycle indicated an increased carcinogenic risk in professionals with high IRS. We suggest that the COVID-19 pandemic could make significant adjustments in the formation of IRS in professionals who have survived the disease and continue to work with ionizing radiation (IR). Increased systemic inflammatory activity, which persists for a long time in COVID-19 patients, in combination with low-dose range irradiation (professionals who continue to work with IR) and with local irradiation in the high-dose range (radiation therapy for cancer patients) may affect IRS. Repeated determination of IRS in professionals who have had COVID-19 infection, using chromosomal G2-radiation sensitivity assay will answer the question: can SARS-CoV-2 coronavirus affect the IRS? The proposed hypothesis of the radiosensitivity evolution needs further experimental validation using a set of radiobiological indices to clarify the mechanism of IRS formation following COVID-19 infection. The detected changes (increase) of human IRS after COVID-19 must be taken into account for personalized planning of radiotherapy of COVID-19 cancer patients.

Influence of bacterial lectin on key regulatory links of functional activity of macrophages in mice with Ehrlich carcinoma.

BACKGROUND: Recent studies have shown the potential of using different approaches for immunotherapy in cancer treatment. Macrophages (Mph) are one of the promising targets for immunotherapy. AIM: To investigate changes in the functional activity of Mph in mice with Ehrlich carcinoma by nitric oxide (NO)/arginase (Arg), IRF4/IRF5 and STAT1/STAT6 ratios caused by administration of lectin from B. subtilis IMV-7724. MATERIALS AND METHODS: From the 2nd day after Ehrlich carcinoma inoculation into female Balb/c mice, lectin from B. subtilis IMV B-7724 (0.02 mg/mouse) was administered for 10 days. The peritoneal Mph were isolated on days 14, 21, and 28 after tumor transplantation and their functional state (NO production, Arg activity and cytotoxic activity) was examined. The levels of mRNA expression of transcription factors STAT-1, STAT-6, IRF5, IRF4 were evaluated. RESULTS: In lectin-treated animals with Ehrlich carcinoma, the functional state of Mph (NO/Arg ratio, index of cytotoxic activity) was maintained at the level of intact mice exceeding the values in untreated animals with Ehrlich carcinoma at late terms of tumor growth (21, 28 days). Analysis of mRNA expression levels of transcription factors in these animals showed a significant increase (p < 0.05) in the ratio of STAT1/STAT6 on the day 21 and IRF5/IRF4 on day 28 of tumor growth compared to that in untreated mice. CONCLUSIONS: Administration of lectin from B. subtilis IMV B-7724 to mice with Ehrlich carcinoma led to the prevalence of Mph exhibiting the functional properties of M1 type at late-term tumor growth. The transcription factors of the STAT and IRF signaling pathways are involved in the process of Mph polarization induced by lectin from B. subtilis IMV B-7724.

Macrophage polarization in dynamics of Lewis lung carcinoma growth and metastasis.

AIM: To assess the functional state of macrophages based on various manifestations of their activity at the different stages of metastatic tumor growth in C57Bl mice. MATERIALS AND METHODS: On days 7, 14, 21 and 28 after Lewis lung carcinoma transplantation to C57Bl mice, macrophages from various anatomic sites were isolated and tested on their cytotoxicity, metabolic activity, NO production and arginase activity. RESULTS: In the populations of peritoneal and splenic macrophages, on days 7 and 21 of tumor growth antitumor (M1) cells prevailed while on days 14 and 28 tumor-promoting (M2) macrophages predominated. In the population of lung macrophages, cells with M1 phenotype were in the majority in the early stages of tumor growth. On days 21 and 28, M1 cells were gradually substituted by cells exhibiting M2 phenotype. This shift correlated with metastasis to lungs. CONCLUSION: Lewis lung carcinoma growth is accompanied by the gradual change in macrophage polarization from antitumor (M1) towards tumor-promoting (M2) type. These changes were more evident in population of lung macrophages and correlated with the parameters of metastasis.

Modern views on the role of main components of stroma and tumor microinvironment in invasion, migration and metastasis.

The review presents modern ideas about tumor microenvironment, which most researchers recognize as the main "player" in tumor cell invasion, cell migration and metastasis. The current data on the main components of the stroma and the microenvironment, which play the role of the driving force in tumor progression, are analyzed. In particular, the review highlights the issues of origin, biological traits, phenotypic plasticity, functional heterogeneity of activated fibroblasts - myofibroblasts and tumor-associated fibroblasts, which in recent years have received much attention. Such components of the extracellular matrix proteome as collagen and matrix metalloproteinases are discussed in detail. They are mostly produced by activated fibroblasts and, on the one hand, initiate the development of desmoplasia due to type I collagen and, on the other hand, promote degradation of extracellular matrix proteins due to metalloproteinases, which generally leads to tissue remodeling that promotes tumor progression. Possibilities of using the most important indicators of extracellular matrix remodeling as potential markers and targets of clinical strategy are discussed.

Biomagnetism of tumor in rats with Guerin's carcinoma after injection of ferromagnetic nanocomposite (Ferroplat): contactless measurement.

AIM: In order to develop fundamentally new technologies for non-invasive and safer diagnosis of cancer, we aimed to detect non-contact magnetic signals from a malignant tumor in animals treated or not-treated with the ferromagnetic nanocomposite Ferroplat. MATERIALS AND METHODS: Guerin's carcinoma was used as a model of tumor growth. The biomagnetism of the tumor was evaluated in the dynamics of its growth. Ten days after tumor transplantation, Ferroplat was administered intravenously to half of the animals with the tumor and to half of the control animals. The magnitude of the magnetic signals was determined 1 h and every two days after administration of the nanocomposite using a Superconducting Quantum Interference Device magnetometer of the original design. RESULTS: We have found that the magnetic signals coming from the tumor are significantly higher compared to control tumor-free animals. Intravenous administration of a ferromagnetic nanocomposite (Ferroplat: Fe3O4 + cisplatinum) led to a significant increase of the magnetic signal, especially in the tumor tissue, and inhibition of Guerin's carcinoma growth. Ferromagnetic nanoparticles (32.7 nm) are retained in malignant cells for a longer time than in normal ones. CONCLUSION: Tumor cells accumulate iron nanoparticles more intensively than normal ones. Nanocomposite Ferroplat can be used for a targeted delivery of cisplatin to malignant cells.

Association of circulating miR-21, -205, and -182 with response of luminal breast cancers to neoadjuvant FAC and AC treatment.

AIM: To identify the association of serum miRNAs with neoadjuvant polychemotherapy response in patients with breast cancer of luminal A and B subtypes. MATERIALS AND METHODS: We analyzed the expression levels of circulating miR-21, -155, -182, -373, -199a, -205, -375 in serum of 182 breast cancer patients using real-time polymerase chain reaction. Each case was characterized by TMN criteria using morphological and immunohistochemical analyses. RESULTS: Serum levels of miR-205 and -375 are associated with the response of luminal A tumors and miR-205 and -21 with the response of luminal B tumors to neoadjuvant polychemotherapy in fluorouracil + doxorubicin + cyclophosphamide and doxorubicin + cyclophosphamide regimens. In addition, we found correlation of miR-155, -182, -199a, -375 with 3-year relapse-free survival of patients. Based on the obtained data, we developed innovative prognostic and predictive panels to assess the drug sensitivity of tumors and lower the risk of breast cancer recurrence, which would significantly improve the treatment outcomes and the quality of life of patients. CONCLUSIONS: Serum levels of miR-155, -182, -199a, -205, -375 can be used as predictive and prognostic panel for monitoring BC course in Ukrainian population.

NANOG as prognostic factor of prostate cancer course.

The variability of the clinical course of prostate cancer (PC) indicates the need to find factors that could predict the aggressive potential of neoplasms accounting the biological characteristics of tumor cells. In this context, the role of NANOG, a transcription factor involved in maintaining pluripotency and one of the markers of cancer stem cells (CSCs), is being actively studied today. AIM: To investigate the level of NANOG mRNA in tumor tissue of patients with PC and to analyze the possibility of its use as a marker of the disease course. MATERIALS AND METHODS: The study involved 85 patients with PC of stages II-IV. Morphological and immunohistochemical studies were performed on serial paraffin sections of resected PC using monoclonal antibodies to Ki-67 and androgen receptor. NANOG and miR-214 mRNA expression in tumor cells was analyzed by real-time reverse transcription polymerase chain reaction. The identification of CSCs was performed by double-labeled immunohistochemical method using primary antibodies to CD24 and CD44. RESULTS: We have revealed notable variability of NANOG mRNA levels in tumor tissue of patients with PC (mean 4.18 ± 0.65 a.u. with individual deviations from 0.11 ± 0.03 a.u. to 15.24 ± 0.36 a.u.). According to NANOG mRNA levels, two groups of the PC patients were delineated: group 1 and group 2, with the average NANOG mRNA levels of 2.12 ± 0.16 a.u., and 8.68 ± 1.24 a.u., respectively. The NANOG mRNA levels in tumor tissue of PC patients of groups 1 and 2 correlated with preoperative serum prostate-specific antigen level (r = 0.58; p < 0.05 and r = 0.64; p < 0.05, respectively), tumor volume (r = 0.42; p < 0.05 and r = 0.72; p < 0.05, respectively), regional lymph node metastases (r = 0.70; p < 0.05 and r = 0.75; p < 0.05, respectively). High NANOG mRNA levels in tumor cells were associated with such molecular and biological features of PC as androgen receptor expression (r = 0.52; p < 0.05), high proliferative activity (r = 0.60; p < 0.05) and the presence of CSC markers (r = 0.75; p < 0.05). CONCLUSIONS: The findings indicate that NANOG is involved in the formation of the PC malignancy and should be further studied as a potential marker for the prediction of the disease course.