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.

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.

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.

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.

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.

Amplifications of Stemness Gene Loci-New Markers for the Determination of the Need for Neoadjuvant Chemotherapy for Patients with Breast Cancer. A Prospective Study.

In this prospective study, a new strategy for the prescription of neoadjuvant chemotherapy (NAC) was prospectively tested and depended on the presence of stemness gene amplifications in the tumor before treatment, which in our early studies showed a connection with metastasis. The study included 92 patients with grade IIA-IIIB luminal B breast cancer. Patients underwent a biopsy before treatment, and with the use of a CytoScan HD Array microarray (Affymetrix, Santa Clara, CA, USA), the presence of stemness gene amplifications (3q, 5p, 6p, 7q, 8q, 13q, 9p, 9q, 10p, 10q21.1, 16p, 18chr, 19p) in the tumor was determined. In group 1 (n = 41), in the presence of two or more amplifications, patients were prescribed a personalized NAC regimen. In group 2 (n = 21), if there was no amplification of stemness genes in the tumor, then patients were not prescribed NAC, and treatment began with surgery. Group 3 (n = 30) served as a historical control. The frequency of an objective response to NAC in groups 1 and 3 was 79%. Nonmetastatic survival was found in 100% of patients in group 2, who did not undergo NAC. In patients in group 1, the frequency of metastasis was 10% (4/41). At the same time, in patients in group 3, who received NAC, the rate of metastasis was 47% (14/30). The differences between group 1 and group 3 and between group 2 and group 3 were statistically significant, both by Fisher's criterion and a log-rank test. The appointment of NAC was most feasible in patients with clones with stemness gene amplifications in the primary tumor, while in the absence of amplifications, preoperative chemotherapy led to a sharp decrease in metastasis-free survival. This strategy of NAC prescription allowed us to achieve 93% metastatic survival in patients with breast cancer.

Transcriptome of Breast Tumors With Different Amplification Status of the Long Arm of Chromosome 8.

BACKGROUND: Amplification of chromosome 8q with locus 8q24 is the most common copy number aberration, and is associated with tumour progression and chemoresistance. MATERIALS AND METHODS: The study used paired samples of biopsy and surgical material from 60 patients with breast cancer. The amplification status of 8q was determined using a CytoScan HD Array microarray; complete transcriptomic analysis was performed using a Human Clariom S Assays microarray (Affymetrix, USA). RESULTS: It was shown that in 65% of cases, amplification of 8q was preserved in the tumour after neoadjuvant chemotherapy (NAC). NAC significantly enhanced the heterogeneity of the transcriptome between tumours with and without amplification of 8q. Compared with a good response, a poor response to NAC also led to increased heterogeneity of the transcriptome of residual tumours. Eight differentially expressed genes of patients with different amplification status of 8q before and after NAC overlapped. CONCLUSION: Amplification of 8q leads to a significant shift in the level of transcription of a large number of genes after exposure to chemotherapy.

Abscopal effect in the radio and immunotherapy.

This review is devoted to a rare in clinical practice, but promising phenomenon of regression distant non-irradiated metastases in combination therapy of cancer patients. R. H. Mole in 1953 suggested introducing the term "abscopal effect" to denote the effect of ionizing radiation "at a distance from the irradiated volume but within the same organism." Currently, it is a hypothesis in the treatment of metastatic cancer, when there is a regression of untreated areas simultaneously with a decrease in the tumor. After the discovery of immune checkpoint cases were increase with patients treated with check-point blockade (especially lymphocyte associated protein 4, programmed cell death 1/programmed cell death 1 ligand 1) and which have an abscopal effect. This review systematizes works covering the time period from 1969 to 2019, which give cases of the abscopal effect at different localizations. However, abscopal effect is a poorly understood phenomenon. In this review, the authors tried to collect all information about the possible mechanisms of the abscopal effect, possible role in antitumor response and frequency abscopal effect at radio/immunotherapy or combined both.

DNA methylation markers panel can improve prediction of response to neoadjuvant chemotherapy in luminal B breast cancer.

Despite the advantages of neoadjuvant chemotherapy (NACT), associated toxicity is a serious complication that renders monitoring of the patients' response to NACT highly important. Thus, prediction of tumor response to treatment is imperative to avoid exposure of potential non-responders to deleterious complications. We have performed genome-wide analysis of DNA methylation by XmaI-RRBS and selected CpG dinucleotides differential methylation of which discriminates luminal B breast cancer samples with different sensitivity to NACT. With this data, we have developed multiplex methylation sensitive restriction enzyme PCR (MSRE-PCR) protocol for determining the methylation status of 10 genes (SLC9A3, C1QL2, DPYS, IRF4, ADCY8, KCNQ2, TERT, SYNDIG1, SKOR2 and GRIK1) that distinguish BC samples with different NACT response. Analysis of these 10 markers by MSRE-PCR in biopsy samples allowed us to reveal three top informative combinations of markers, (1) IRF4 and C1QL2; (2) IRF4, C1QL2, and ADCY8; (3) IRF4, C1QL2, and DPYS, with the areas under ROC curves (AUCs) of 0.75, 0.78 and 0.74, respectively. A classifier based on IRF4 and C1QL2 better meets the diagnostic panel simplicity requirements, as it consists of only two markers. Diagnostic accuracy of the panel of these two markers is 0.75, with the sensitivity of 75% and specificity of 75%.

Neoadjuvant Chemotherapy Induces the Appearance of New Copy Number Aberrations in Breast Tumor and is Associated with Metastasis.

BACKGROUND: In this study, we examined the CNA-genetic landscape (CNA - copy number aberration) of breast cancer prior to and following neoadjuvant chemotherapy (NAC) and correlated changes in the tumor landscape with chemotherapy efficiency as well as metastasis-free survival. OBJECTIVE: Breast cancer patients (n = 30) with luminal B molecular subtypes were treated with anthracycline- based therapy. METHODS: To study CNAs in breast tumors, microarray analysis was performed. RESULTS: Three effects of NAC on tumor CNA landscape were identified: 1 - the number of CNAbearing tumor clones decreased following NAC; 2 - there were no alterations in the number of CNAcontaining clones after NAC; 3 - the treatment with NAC increased the number of CNA-bearing clones (new clones appeared). All NAC-treated patients who had new tumor clones with amplification (20%) had a 100% likelihood of metastasis formation. In these cases, NAC contributed to the emergence of potential metastatic clones. Our study identified the following loci - 5p, 6p, 7q, 8q, 9p, 10p, 10q22.1, 13q, 16p, 18Chr and 19p - that were amplified during the treatment with NAC and maybe the markers of potential metastatic clones. In other patients who showed total or partial elimination of CNA-bearing cell clones, no new amplification clones were observed after NAC, and no evidence of metastases was found with follow-up for 5 years (р = 0.00000). CONCLUSION: Our data suggest that the main therapeutic result from NAC is the elimination of potential metastatic clones present in the tumor before treatment. The results showed the necessity of an intelligent approach to NAC to avoid metastasis stimulation.

Amplification of Stem Genes: New Potential Metastatic Makers in Patients with an Early Form of Breast Cancer.

BACKGROUND: According to our previous studies, the presence of amplifications of stem genes can lead to their ectopic expression and this is associated with an increased activity of tumor stem cells in these patients. This leads to a high aggressiveness of the tumor and the development of metastatic disease. The aim was to evaluate the prognostic significance of the presence of amplifications of stem genes and their expression in patients with early breast cancer (BC). METHODS: The study included 28 patients with T1NxM0 BC. We used surgical specimens, including formalin-fixed paraffin-embedded archive materials, for 8 patients. A microarray analysis was performed on high-density DNA chips from CytoScanHDArray to assess the status of copy number aberration (CNA) of stem genes locus. Gene expression was assessed using RT-qPCR. RESULTS: CNA analysis of the studied tumors of patients without chemotherapy showed that 17/18 patients without metastases did not have two or more amplifications of chromosomal regions. Ten patients had visceral metastases. In 9/10 of these patients in the primary tumor there were two or more amplifications of the stem genes locus. Two or more amplifications of stem genes locus were found in 12 patients with stage I. Hematogenous metastases did not develop in all patients. Comparison of metastasis-free survival rates in groups of patients with 1 or without amplifications and with two or more amplifications showed statistically significant differences (P = 0.01). CONCLUSION: Our studies have shown that the presence of clones with two or more amplifications of stem gene in patients with BC T1NxM0 has a significant prognostic value and determines an unfavorable prognosis for distant metastasis.

Genome-wide methylotyping resolves breast cancer epigenetic heterogeneity and suggests novel therapeutic perspectives.

Aim: To provide a breast cancer (BC) methylotype classification by genome-wide CpG islands bisulfite DNA sequencing. Materials & methods: XmaI-reduced representation bisulfite sequencing DNA methylation sequencing method was used to profile DNA methylation of 110 BC samples and 6 normal breast samples. Intrinsic DNA methylation BC subtypes were elicited by unsupervised hierarchical cluster analysis, and cluster-specific differentially methylated genes were identified. Results & conclusion: Overall, six distinct BC methylotypes were identified. BC cell lines constitute a separate group extremely highly methylated at the CpG islands. In turn, primary BC samples segregate into two major subtypes, highly and moderately methylated. Highly and moderately methylated superclusters, each incorporate three distinct epigenomic BC clusters with specific features, suggesting novel perspectives for personalized therapy.

Human papillomavirus and colorectal cancer.

The involvement of human papillomavirus in carcinogenesis of colorectal cancer is a contentious issue. The presented meta-analysis was performed to systematize the currently available research results on the matter. The analysis was based on the data from 19 studies to assess the association of HPV infection with colorectal cancer. According to the obtained data, researchers determined the statistically significant level of HPV infection in tumor tissue of CRC and the resulting relative risk of developing CRC with HPV infection to be RR (95% CI) = 2.97 (1.42-6.22) with p = 0.0039.