Mechanisms and significance of entosis for tumour growth and progression.

To date, numerous mechanisms have been identified in which one cell engulfs another, resulting in the creation of 'cell-in-cell' (CIC) structures, which subsequently cause cell death. One of the mechanisms of formation of these structures is entosis, which is presumably associated with possible carcinogenesis and tumour progression. The peculiarity of the process is that entotic cells themselves actively invade the host cell, and afterwards have several possible variants of fate. Entotic formations are structures where one cell is engulfed by another cell, creating a cell-in-cell structure. The nucleus of the outer cell has a crescent shape, while the inner cell is surrounded by a large entotic vacuole. These characteristics differentiate entosis from cell cannibalism. It's worth noting that entotic formations are not necessarily harmful and may even be beneficial in some cases. In this article we will consider the mechanism of entosis and variants of entotic cell death, and also put forward hypothesis about possible variants of participation of this process on the formation and progression of cancer. This article also presents our proposed classification of functional forms of entosis.

Gene Expression Profile-Guided Personalized Intraperitoneal Chemotherapy for Gastric Cancer Peritoneal Carcinomatosis.

Background: Peritoneal carcinomatosis (PC) is one of the most unfavorable sites of metastasis for malignant tumors of various localizations, especially gastric cancer (GC). According to the literature, synchronous PC in GC is common in 15-52% of patients. The purpose of this study was to examine the long-term results using personalized systemic and intraperitoneal chemotherapy as part of the combined treatment of stomach cancer presenting with synchronous PC. Methods: Cytoreductive surgical treatment was performed for 70 patients at the first stage. The control group (n = 35) received standard postoperative chemotherapy according to the FOLFOX scheme. Personalized postoperative systemic and intraperitoneal chemotherapy was administered in the basic group (n = 35), based on the expression levels of the eight genes in the primary tumor, lymph node, and peritoneal metastases. Results: The median progression-free survival was 14.9 months in the basic group, and in the control group it was 11.2 months (P < 0.001). The median life expectancy in the basic group was 16.8 (13.7 - 18.8) months, in the control group it was 12.5 (11.3 - 13.1) months (P < 0.001). Conclusions: Developing algorithms of personalized systemic and intraperitoneal chemotherapy in patients with GC with synchronous carcinomatosis, based on the analysis of molecular genetic characteristics of the tumor and metastases, allows to improve the long-term results of combined treatment.

Prevention of Metastasis by Suppression of Stemness Genes Using a Combination of microRNAs.

We propose an original strategy for metastasis prevention using a combination of three microRNAs that blocks the dedifferentiation of cancer cells in a metastatic niche owing to the downregulation of stemness genes. Transcriptome microarray analysis was applied to identify the effects of a mixture of microRNAs on the pattern of differentially expressed genes in human breast cancer cell lines. Treatment of differentiated CD44- cancer cells with the microRNA mixture inhibited their ability to form mammospheres in vitro. The combination of these three microRNAs encapsulated into lipid nanoparticles prevented lung metastasis in a mouse model of spontaneous metastasis. The mixture of three microRNAs (miR-195-5p/miR-520a/miR-630) holds promise for the development of an antimetastatic therapeutic that blocks tumor cell dedifferentiation, which occurs at secondary tumor sites and determines the transition of micrometastases to macrometastases.

Microarray Analysis for Transcriptomic Profiling of Myocardium in Patients with Fatal Myocardial Infarction.

Transcriptomic evidence from human myocardium in myocardial infarction (MI) is still not sufficient. Thus, there is a need for studies on human cardiac samples in relation to the clinical data of patients. The purpose of our pilot study was to investigate the transcriptomic profile of myocardium in the infarct zone, in comparison to the remote myocardium, in patients with fatal MI, via microarray analysis. This study included four patients with fatal MI type 1. We selected histologically verified samples from within the infarct area (n = 4) and remote myocardium (n = 4). The whole transcriptome was evaluated using microarray analysis. Differentially expressed genes (DEGs) clustered in the infarct area and in the remote myocardium allowed their differentiation. We identified a total of 1785 DEGs (8.32%) in the infarct area, including 1692 up-regulated (94.79%) and 93 down-regulated (5.21%) genes. The top 10 up-regulated genes were TRAIL, SUCLA2, NAE1, PDCL3, OSBPL5, FCGR2C, SELE, CEP63, ST3GAL3 and C4orf3. In the infarct area, we found up-regulation of seventeen apoptosis-related genes, eleven necroptosis-related, and six necrosis-related genes. Transcriptome profiling of the myocardium in patients with MI remains a relevant area of research for the formation of new scientific hypotheses and a potential way to increase the translational significance of studies into myocardial infarction.

Organ-Specificity of Breast Cancer Metastasis.

Breast cancer (BC) remains one of the most common malignancies among women worldwide. Breast cancer shows metastatic heterogeneity with priority to different organs, which leads to differences in prognosis and response to therapy among patients. The main targets for metastasis in BC are the bone, lung, liver and brain. The molecular mechanism of BC organ-specificity is still under investigation. In recent years, the appearance of new genomic approaches has led to unprecedented changes in the understanding of breast cancer metastasis organ-specificity and has provided a new platform for the development of more effective therapeutic agents. This review summarises recent data on molecular organ-specific markers of metastasis as the basis of a possible therapeutic approach in order to improve the diagnosis and prognosis of patients with metastatically heterogeneous breast cancer.

Human papillomavirus and prostate cancer: systematic review and meta-analysis.

The involvement of human papillomavirus (HPV) in the prostate carcinogenesis is a controversial issue. The presented meta-analysis was carried out to systematize the currently available research results regarding this question. The meta-analysis includes case-control studies from 1991 to 2022, which were collected from publicly available bibliometric databases. The meta-analysis was performed using Meta-Essentials_1.5 software. We used Begg's and Egger's methods to assess publication bias. Cochran's Q test was used to assess heterogeneity and the I2 index was employed for calculating the variation in the pooled estimations. The analysis was based on data from 27 case-control studies, which in total yielded 1607 tumour tissue samples of prostate and 1515 control samples (317 samples of normal tissue, 1198 samples of benign prostatic hyperplasia (BPH)). According to the data obtained, there was high risk of prostate cancer by HPV infection in both cases. HPV was found in prostate cancer in 25.8% of cases, while in normal tissue samples the virus was detected in 9.2% of cases and in 17.4% with BPH as a control. In particular, more studies on the association of HPV and prostate cancer are needed to prove the role of HPV in the development of prostate cancer. In addition to the controversial question of whether HPV infection is associated with prostate cancer risk, it is worth considering whether the samples used as a control have an impact on the results. The impact of HPV in prostate tumour tissue samples on outcome should also be investigated.

Mutations of BRCA1, BRCA2, and PALB2 Genes in Breast Tumor Tissue: Relationship with the Effectiveness of Neoadjuvant Chemotherapy and Disease Prognosis.

It has been shown that the loss of function of the BRCA1, BRCA2, and PALB2 genes due to a number of hereditary mutations or chromosomal aberrations can affect the effectiveness of chemotherapy treatment and disease prognosis in patients with various types of cancer, and in particular in breast cancer. Thus, the aim of the work was to evaluate the predictive and prognostic potential of DNA copy number aberrations and mutations in the BRCA1, BRCA2, and PALB2 genes in breast tumors. MATERIALS AND METHODS: The study included 66 patients with breast cancer. DNA copy number aberrations (CNA) were assessed by high-density CytoScanHD™ Array micro matrix analysis. Gene mutations were assessed by sequencing on the MiSeq™ Sequencing System using the Accel-Amplicon BRCA1, BRCA2, and PALB2 Panel. RESULTS: It has been established that the presence of a normal copy number of PALB2 is associated with a lack of response to chemotherapy in Taxotere-containing treatment regimens (p = 0.05). In addition, the presence of a PALB2 deletion is associated with 100% metastatic survival rates (log-rank test p = 0.04). As a result of sequencing, 25 mutations were found in the BRCA1 gene, 42 mutations in BRCA2, and 27 mutations in the PALB2 gene. The effect of mutations on the effectiveness of treatment is controversial, but an effect on the survival of patients with breast cancer has been shown. So, in the presence of pathogenic mutations in the BRCA2 gene, 100% metastatic survival is observed (log-rank test p = 0.05), as well as in the elimination of PALB2 mutations during treatment (log-rank test p = 0.07). CONCLUSION: Currently, there is little data on the effect of chromosomal aberrations and mutations in the BRCA1/2 and PALB2 genes on the effectiveness of treatment and prognosis of the disease. At the same time, the study of these genes has great potential for testing focused on a personalized approach to the treatment of patients with breast cancer.

WNT-Conditioned Mechanism of Exit from Postchemotherapy Shock of Differentiated Tumour Cells.

BACKGROUND: the present study aims to prove or disprove the hypothesis that the state of copy number aberration (CNA) activation of WNT signalling pathway genes accounts for the ability of differentiated tumour cells to emerge from postchemotherapy shock. METHODS: In the first step, the CNA genetic landscape of breast cancer cell lines BT-474, BT-549, MDA-MB-231, MDA-MD-468, MCF7, SK-BR-3 and T47D, which were obtained from ATCC, was examined to rank cell cultures according to the degree of ectopic activation of the WNT signalling pathway. Then two lines of T47D with ectopic activation and BT-474 without activation were selected. The differentiated EpCAM+CD44-CD24-/+ cells of these lines were subjected to IL6 de-differentiation with formation of mammospheres on the background of cisplatin and WNT signalling inhibitor ICG-001. RESULTS: it was found that T47D cells with ectopic WNT signalling activation after cisplatin exposure were dedifferentiated to form mammospheres while BT-474 cells without ectopic WNT-signalling activation did not form mammospheres. The dedifferentiation of T47D cells after cisplatin exposure was completely suppressed by the WNT signalling inhibitor ICG-001. Separately, ICG-001 reduced, but did not abolish, the ability to dedifferentiate in both cell lines. CONCLUSIONS: these data support the hypothesis that the emergence of differentiated tumour cells from postchemotherapy shock after chemotherapy is due to ectopic activation of WNT signalling pathway genes.

Tumor-associated macrophages respond to chemotherapy by detrimental transcriptional reprogramming and suppressing stabilin-1 mediated clearance of EGF.

Introduction: Tumor resistance to chemotherapy and metastatic relapse account for more than 90% of cancer specific mortality. Tumor-associated macrophages (TAMs) can process chemotherapeutic agents and impair their action. Little is known about the direct effects of chemotherapy on TAMs. Methods: The effect of chemotherapeutic platinum agent cisplatin was assessed in the model system of human ex vivo TAMs. Whole-transcriptome sequencing for paired TAMs stimulated and not stimulated by cisplatin was analysed by NGS. Endocytic uptake of EGF was quantified by flow cytometry. Confocal microscopy was used to visualize stabilin-1-mediated internalization and endocytic trafficking of EGF in CHO cells expressing ectopically recombinant stabilin-1 and in stabilin-1+ TAMs. In cohort of patients with breast cancer, the effect of platinum therapy on the transcriptome of TAMs was validated, and differential expression of regulators of endocytosis was identified. Results: Here we show that chemotherapeutic agent cisplatin can initiate detrimental transcriptional and functional programs in TAMs, without significant impairment of their viability. We focused on the clearance function of TAMs that controls composition of tumor microenvironment. For the first time we demonstrated that TAMs' scavenger receptor stabilin-1 is responsible for the clearance of epidermal growth factor (EGF), a potent stimulator of tumor growth. Cisplatin suppressed both overall and EGF-specific endocytosis in TAMs by bidirectional mode: suppression of positive regulators and stimulation of negative regulators of endocytosis, with strongest effect on synaptotagmin-11 (SYT11), confirmed in patients with breast cancer. Conclusion: Our data demonstrate that synergistic action of cytostatic agents and innovative immunomodulators is required to overcome cancer therapy resistance.

DNA Methylation and Prospects for Predicting the Therapeutic Effect of Neoadjuvant Chemotherapy for Triple-Negative and Luminal B Breast Cancer.

Despite advances in the diagnosis and treatment of breast cancer (BC), the main cause of deaths is resistance to existing therapies. An approach to improve the effectiveness of therapy in patients with aggressive BC subtypes is neoadjuvant chemotherapy (NACT). Yet, the response to NACT for aggressive subtypes is less than 65% according to large clinical trials. An obvious fact is the lack of biomarkers predicting the therapeutic effect of NACT. In a search for epigenetic markers, we performed genome-wide differential methylation screening by XmaI-RRBS in cohorts of NACT responders and nonresponders, for triple-negative (TN) and luminal B tumors. The predictive potential of the most discriminative loci was further assessed in independent cohorts by methylation-sensitive restriction enzyme quantitative PCR (MSRE-qPCR), a promising method for the implementation of DNA methylation markers in diagnostic laboratories. The selected most informative individual markers were combined into panels demonstrating cvAUC = 0.83 (TMEM132D and MYO15B markers panel) for TN tumors and cvAUC = 0.76 (TTC34, LTBR and CLEC14A) for luminal B tumors. The combination of methylation markers with clinical features that correlate with NACT effect (clinical stage for TN and lymph node status for luminal B tumors) produces better classifiers, with cvAUC = 0.87 for TN tumors and cvAUC = 0.83 for luminal B tumors. Thus, clinical characteristics predictive of NACT response are independently additive to the epigenetic classifier and in combination improve prediction.

Human Papillomavirus in Non-Small Cell Lung Carcinoma: Assessing Virus Presence in Tumor and Normal Tissues and Its Clinical Relevance.

The significance of the role of human papillomavirus (HPV) in the development of lung cancer remains an open question. The data from the literature do not provide conclusive evidence of HPV being involved in the pathogenesis of lung cancer. The aim of this work was to detect the presence of HPV infections with a high carcinogenic risk in patients with non-small cell lung cancer (NSCLC). MATERIALS AND METHODS: the study involved 274 patients with stage IIA-IIIB non-small cell lung cancer. We analyzed normal and tumor tissues as well as blood from each patient. DNA was extracted from patients' specimens, and HPV detection and genotyping was carried out using commercially available kits by PCR. RESULTS: HPV was detected in 12.7% of the patients (35/274 of all cases). We detected nine different types of human papillomavirus in the patients, namely, types 16, 18, 31, 35, 45, 51, 52, 56, and 59. The HPV-positive samples had a clinically insignificant viral load and were predominantly integrated. The relationship between the presence of HPV and its virological parameters and the clinical and pathological parameters of the patients was established. A metastatic-free survival analysis showed that all patients with HPV in the tumor tissue had a higher 5-year survival rate (94%) compared with the HPV-negative patients (78%). The result was not statistically significant (p = 0.08). CONCLUSIONS: data showing a 12.7% human papillomavirus representation among patients with non-small cell lung cancer were obtained. The presence/absence of a viral component in patients with lung cancer was a clinically significant parameter. HPV types 16, 18, and 56, which are the most oncogenic, were most often detected.

Whole Transcriptome Analysis of Breast Cancer Tumors during Neoadjuvant Chemotherapy: Association with Hematogenous Metastasis.

The assessment of molecular genetic landscape changes during NAC and the relationship between molecular signatures in residual tumors are promising approaches for identifying effective markers of outcome in breast cancer. The majority of the data in the literature present the relationship between the molecular genetic landscape and the response to NAC or are simply descriptive. The present study aimed to determine changes in expression profiles during NAC and assess the relationship between gene expression and the outcome of patients with luminal B HER2 breast cancer depending on distant hematogenous metastasis. The study included 39 patients with luminal B HER2-BC. The patients received 6-8 courses of NAC, and paired samples consisting of biopsy and surgical materials were analyzed. A full transcriptome microarray analysis was performed using the human Clariom™ S Assay platform (Affymetrix, 3450 Central Expy, Santa Clara, CA, 95051, USA). A comparison of the expression profiles of patients with breast cancer before and after NAC, depending on the status of hematogenous metastasis, was conducted. It was shown that the amount of DEGs in the tumor was reduced by more than six times after NAC. The top 10 signaling pathways were also found, the activity of which varied depending on the status of hematogenous metastasis before and after NAC. In addition, the association of DEGs with hematogenous metastasis in patients with breast cancer was evaluated: MFS was assessed depending on the expression level of 21 genes. It was shown that MFS was significantly associated with the expression level and pattern of nine genes. The expression levels of nine DEGs in the tumors of patients with breast cancer after NAC were significantly correlated with MFS when the status of hematogenous metastasis was taken into account.

Personalized Prescription of Chemotherapy Based on Assessment of mRNA Expression of BRCA1, RRM1, ERCC1, TOP1, TOP2α, TUBß3, TYMS, and GSTP1 Genes in Tumors Compared to Standard Chemotherapy in the Treatment of Non-Small-Cell Lung Cancer

Objectives: A growing body of evidence suggests the important role of chemosensitive gene expression in the prognosis of patients with lung cancer. However, studies on combined gene expression assessments for personalized prescriptions of chemotherapy regimens in patients have not yet been conducted. The aim of this work was to conduct a prospective study on the appointment of personalized chemotherapy in patients with non-small-cell lung cancer. Materials and methods: The present study analyzed 85 patients with lung cancer (stage IIB-IIIB). Within this group, 48 patients received individualized chemotherapy, and 37 patients received classical chemotherapy. In the individualized chemotherapy group, the mRNA expression levels of ERCC1, RRM1, TUBB3, TYMS, TOP1, TOP2α, BRCA1, and GSTP1 in lung tissues were measured by quantitative real-time PCR (qPCR), and an individual chemotherapy regimen was developed for each patient according to the results. Patients in the classical chemotherapy group received the vinorelbine/carboplatin regimen. Survival analyses were performed using the Kaplan−Meier method. Prognostic factors of metastasis-free survival (MFS) and overall survival (OS) of patients were identified via Cox's proportional hazards regression model. Results: MFS and OS were significantly better in the personalized chemotherapy group compared to the classic chemotherapy group (MFS, 46.22 vs. 22.9 months, p = 0.05; OS, 58.6 vs. 26.9 months, p < 0.0001). Importantly, the best metastasis-free survival rates in the group with personalized ACT were achieved in patients treated with the paclitaxel/carboplatin regimen. Based on an assessment of chemosensitivity gene expression in the tumors, the classical chemotherapy strategy also increased the risk of death (HR = 14.82; 95% CI: 3.33−65.86; p < 0.000) but not metastasis (HR = 1.95; 95% CI: 0.96−3.98; p = 0.06) compared to the group of patients with chemotherapy. Conclusions: The use of combined ERCC1, RRM1, TUBB3, TYMS, TOP1, TOP2α, BRCA1, and GSTP1 gene expression results for personalized chemotherapy can improve treatment efficacy and reduce unnecessary toxicity.

DNA Copy Number Aberrations and Expression of ABC Transporter Genes in Breast Tumour: Correlation with the Effect of Neoadjuvant Chemotherapy and Prognosis of the Disease.

One of the important reasons for the ineffectiveness of chemotherapy in breast cancer (BC) is considered to be the formation of a multidrug resistance phenotype in tumour cells, which is caused by the expression of energy-dependent ABC transporters. The aim of this work was to assess chromosomal aberrations and the level of transcripts of all 49 known ABC transporter genes in breast tumours. MATERIALS AND METHODS: The study included 129 patients with breast cancer. A microarray study of all tumour samples was carried out on microchips. RESULTS: This study established that the presence of a deletion in genes ABCB1, ABCB4, ABCB8, ABCC7, ABCC11, ABCC12, ABCF2, and ABCG4 is associated with an objective response to treatment (p ≤ 0.05). A decrease in the expression of genes was associated with a good response to chemotherapy, whereas an increase in expression caused the progression and stabilization of the tumour. Analysis of metastatic-free survival rates showed that the presence of ABCB1/4 and ABCC1/6 deletions was associated with 100% survival (log-rank test p = 0.01 and p = 0.03). CONCLUSIONS: The study showed that the aberrant state of ABC transporter genes, as well as a decrease in the expression of these genes, is a predictor of the effectiveness of therapeutic treatment and a potential prognostic marker of metastatic survival.

Tumour Stem Cells in Breast Cancer.

Tumour stem cells (CSCs) are a self-renewing population that plays important roles in tumour initiation, recurrence, and metastasis. Although the medical literature is extensive, problems with CSC identification and cancer therapy remain. This review provides the main mechanisms of CSC action in breast cancer (BC): CSC markers and signalling pathways, heterogeneity, plasticity, and ecological behaviour. The dynamic heterogeneity of CSCs and the dynamic transitions of CSC- non-CSCs and their significance for metastasis are considered.

Stem gene expression in breast tumors during chemotherapy: Connection with the main clinical and morphological factors and the disease outcome.

Introduction: In this research, we studied how the expression of 14 stem genes (TERT; OCT3; SMO; MYC; SNAI2; MOB3B; KLF4; BMI1; VIM; FLT3; LAT; SMAD2; LMNB2; KLF1), as well as the TGF-ß1 cytokine gene and its TGFBR1 receptor in breast tumors before and after NAC is associated with clinical and morphological parameters and the disease outcome. Materials and Methods: The study included 82 patients with the morphologically verified diagnosis of T1-4N0-3M0 breast cancer (stages IIA - IIIB). The material was paired biopsy samples of tumor and surgical material for each patient. The stem genes expression was analyzed via qPCR. Results: As a result, we found that increased level of stem genes expression in breast tumors is associated with lymphogenic metastasis, young age, small tumor size, expression of estrogen and progesterone receptors, and the luminal B molecular subtype. NAC stimulates the expression of 7 out of 16 stem genes. Patients who further developed hematogenic metastases have twice as many hyperexpressed stem genes in their tumors before the treatment and after NAC than patients with no hematogenic metastases. The expression level of three genes - OCT3, LAT, and LMNB2 - in a residual tumor allows us to predict metastasis-free survival of patients with breast cancer of various molecular subtypes with a 79% accuracy. Conclusion: Thus, stem genes hyperexpression is associated with tumor progression.

Predictive and Prognostic Significance of mRNA Expression and DNA Copies Aberrations of ERCC1, RRM1, TOP1, TOP2A, TUBB3, TYMS, and GSTP1 Genes in Patients with Breast Cancer.

Increasingly, many researchers are focusing on the sensitivity in breast tumors (BC) to certain chemotherapy drugs and have personalized their research based on the assessment of this sensitivity. One such personalized approach is to assess the chemotherapy's gene expression, as well as aberrations in the number of DNA copies-deletions and amplifications with the ability to have a significant effect on the gene's activity. Thus, the aim of this work was to study the predictive and prognostic significance of the expression and chromosomal aberrations of eight chemosensitivity genes in breast cancer patients. MATERIAL AND METHODS: The study involved 97 patients with luminal B breast cancer IIB-IIIB stages. DNA and RNA were isolated from samples of tumor tissue before and after treatment. Microarray analysis was performed for all samples on high-density microarrays (DNA chips) of Affymetrix (USA) CytoScanTM HD Array and Clariom™ S Assay, human. Detection of expression level of seven chemosensitivity genes-RRM1, ERCC1, TOP1, TOP2a, TUBB3, TYMS, and GSTP1-was performed using PCR real-time (RT-qPCR). RESULTS: The expression of the RRM1 (AC scheme), TOP2α, TYMS, and TUBB3 genes in patients with an objective response to treatment (complete and partial regression) is higher than in patients with stabilization and progression (p < 0.05). According to our results, the presence of a high level of GSTP1 in a tumor biopsy is associated with the low efficiency of the NAC CP scheme (p = 0.05). The presence of RRM1 deletion is associated with complete and partial regression, as for the TOP1 and TUBB3 genes (p < 0.05). Higher rates of metastatic survival are associated with a high level of expression and amplification of the GSTP1 gene (log-rank test p = 0.02 and p = 0.05). CONCLUSION: Thus, a complex assessment of the chemotherapy's gene expression is important not only for understanding the heterogeneity and molecular biology of breast cancer but also to obtain a more accurate disease prognosis.

Determination of BRCAness Phenotype in Breast Tumors for the Appointment of Neoadjuvant Chemotherapy Based on Platinum and Taxanes.

The concept of BRCAness was developed because of similarities between sporadic and hereditary breast cancer. BRCAness defines the pathogenesis and treatment sensitivity of many types of cancer, as well as the presence of a defect in the homologous recombination repair of tumor cells simulating the loss of BRCA1 or BRCA2, as in the presence of germline mutations. The question of treatment effectiveness for BRCA-like tumors is controversial and open. Thus, the aim of this work was to study the effectiveness of neoadjuvant chemotherapy (NAC) in BRCA-deficient breast cancer patients without germline mutations. The study involved 130 patients with breast cancer in stages IIA-IIIB. The treatment regimen included neoadjuvant chemotherapy, surgery, and adjuvant chemotherapy. The materials used were tumor samples from before and after chemotherapy. DNA and RNA were isolated from the tumor material. RNA was used to assess the expression level of BRCA1, while DNA was used for methyl-sensitive PCR. A microarray analysis was performed on high-density DNA chips from an Affymetrix CytoScanTM HD Array to assess DNA copy number aberration (CNA status) and loss of heterozygosity. A statistical analysis was performed using the Statistica 8.0 application package. It was noted that the existence of copy number aberrations in genes was statistically significantly associated with tumor treatment response and disease prognosis. Patients with partial regression had a statistically significantly higher amount of deletion than patients without an objective response (5/25 patients; 16%), as shown in the general sample of patients (52.9% versus 27.1%, respectively) at p = 0.0001 and in patients treated with anthracycline-containing regimen (p = 0.0001). In addition, it was shown that patients with BRCA1 deletion had higher rates of metastatic-free survival (log rank test, p = 0.009). BRCAness patients had a higher rate of 5-year metastatic survival, but not of treatment efficacy. The prospective study showed the positive effect of assessing the BRCAness phenotype of a tumor before treatment and of prescribing personalized NAC regimens. The objective response rate was statistically significantly more often observed in the group of patients with personalized chemotherapy (85.0% (34/40 patients) versus 62.3% (56/90 patients); p = 0.007). Despite the controversial effectiveness of BRCA-like tumor treatment, our data showed high predictive and prognostic significance of the BRCAness phenotype for the personalization of platinum and taxane regimens.

Molecular-Genetic Portrait of Breast Cancer with Triple Negative Phenotype.

Understanding of the genetic mechanisms and identification of the biological markers of tumor progression that form the individual molecular phenotype of transformed cells can characterize the degree of tumor malignancy, the ability to metastasize, the hormonal sensitivity, and the effectiveness of chemotherapy, etc. Breast cancer (BC) is a genetically heterogeneous disease with different molecular biological and clinical characteristics. The available knowledge about the genetic heterogeneity of the most aggressive molecular subtype of breast cancer-triple-negative (TN)-has led to discoveries in drug treatment, including the use of DNA damaging agents (platinum and PARP inhibitors) for these tumors, as well as the use of immunotherapy. Most importantly, the ability to prescribe optimal drug treatment regimens for patients with TNBC based on knowledge of the molecular-genetic characteristics of this subtype of BC will allow the achievement of high rates of overall and disease-free survival. Thus, identification of the molecular-genetic phenotype of breast cancer is an important prognostic factor of the disease and allows personalization of the patient's treatment.

Investigation of somatic PIK3CA gene mutations in breast cancer patients.

PURPOSE: Mutations of the PI3K/AKT/mTOR signaling pathway occur in 70% of all breast cancers and represent a clinically useful marker for disease prognosis and patient management. The purpose of this work was to study the main somatic PIK3CA gene mutations in breast cancer patients and the search for a relationship with the main clinical and pathological characteristics and the effect of neoadjuvant chemotherapy (NAC). METHODS: The study involved 29 patients with luminal B breast cancer. DNA was isolated from samples of tumor tissue before and after treatment using the QIAamp DNA mini Kit (Qiagen, Germany). Samples were prepared for sequencing by amplification with primers containing TruSeq index and adapter sequences (Illumina, USA) using Encyclo polymerase. RESULTS: We found 5 different somatic changes in 28% of patients: c.3140A> G (p.His1047Arg), c.3140A> T (p.His1047Leu), c.1624G> A (p.Glu542Lys), c.1633G> A ( p.Glu545Lys), c.3145G> C (p.Gly1049Arg). In the group of patients with mutations, 50% showed PIK3CA gene amplifications. The c.3140A> T (p.His1047Leu) mutation was associated with low disease-free survival rates. PIK3CA gene mutations were observed in 38% of patients with HER2-subtype, and metastasis-free survival rates were, on average, 1.5 times higher than in patients with normal gene status.