scholarly journals Changes in the methylation level of microRNA genes as a factor of breast cancer development and progression

2021 ◽  
pp. 4-11
Author(s):  
Е.А. Филиппова ◽  
А.М. Бурденный ◽  
С.С. Лукина ◽  
Н.А. Иванова ◽  
И.В. Пронина ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Gene Expression ◽  
Methylation Level ◽  
Molecular Subtype ◽  
Regulation Of Gene Expression ◽  
Epigenetic Mechanism ◽  
Cancer Tissue ◽  
Aberrant Methylation ◽  
Suppressor Genes ◽  
Mirna Genes

Введение. Метилирование как процесс эпигенетической регуляции экспрессии генов является важнейшим в поддержании геномной стабильности. В норме этот процесс определяет подавление активности онкогенов и поддержание работы супрессоров опухолевого роста. Другим важнейшим эпигенетическим регулятором являются микроРНК. Нарушения метилирования CpG-островков в промоторных районах генов, кодирующих микроРНК, являются важнейшим фактором онкогенеза. Цель - расширение спектра генов микроРНК гиперметилируемых при раке молочной железы и изучение их связи с метастазированием и иммуногистохимическим статусом опухоли. Методика. В настоящей работе был проведен отбор ряда генов микроРНК, изменяющих уровень метилирования при раке молочной железы. Методом количественной метилспецифичной ПЦР на представительной выборке из 70 парных образцов рака молочной железы изучен уровень метилирования 8 генов микроРНК, ассоциированных с раком молочной железы: MIR107, MIR124-2, MIR1258, MIR130B, MIR137, MIR191, MIR203А, MIR339. Результаты. Показано статистически значимое увеличение уровня метилирования в опухолевой ткани РМЖ по сравнению с гистологически нормальной тканью молочной железы для генов MIR107, MIR124-2, MIR1258, MIR130В, MIR137, MIR339 и снижение уровня метилирования для гена MIR191. Кроме того, показано статистически значимое увеличение уровня метилирования на III-IV (поздних) стадиях РМЖ для генов MIR107, MIR1258, MIR130В, MIR137, MIR339, в опухолях с большим размером - MIR107, MIR1258, MIR130В, MIR137, MIR339, с низким уровнем дифференцировки - MIR124-2, с наличием метастазов в лимфатические узлы - MIR107, MIR1258, MIR137, MIR339. Опухоли, не экспрессирующие рецептор прогестерона (PR), имеют статистически значимо более высокий уровень метилирования генов MIR137, MIR339. Заключение. Таким образом, определены новые молекулярные показатели прогрессии РМЖ и биомаркеры, которые могут быть использованы при дифференциальной диагностике молекулярного подтипа РМЖ. Background. Methylation, as an epigenetic mechanism for regulation of gene expression, is crucial for the genome stability. Normally, this process is characterized by the ability to silence the oncogene activity and to support the action of suppressor genes. MicroRNAs (miRNAs) are another key epigenetic regulator of gene expression. Aberrant methylation of CpG islands in promoter regions of the genes that code miRNAs is the most important oncogenic factor. Aim. To expand the spectrum of miRNA genes hypermethylated in breast cancer and to study their relationship with metastasis and immunohistochemical status of the tumor. Methods. MiRNA tumor suppressor genes were selected that changed their methylation level in breast cancer patients. Using the method of quantitative methylation-specific PCR, the methylation level of eight miRNA genes associated with breast cancer was studied on a representative set of 70 paired breast cancer samples: MIR107, MIR124-2, MIR1258, MIR130B, MIR137, MIR191, MIR203A, and MIR339. Results. The methylation level of the genes MIR-107, MIR124-2, MIR1258, MIR130B, MIR137, MIR339 was significantly higher in breast cancer tissue compared to normal breast tissue whereas for the gene MIR191, it was significantly lower. Also, the methylation levels of genes MIR107, MIR1258, MIR130B, MIR137, and MIR339 were significantly increased at stages III-IV (advanced) breast cancer; in large tumors, the methylation levels were increased for MIR107, MIR1258, MIR130B, MIR137, and MIR339; in poorly differentiated tumors, the methylation level was increased for MIR124-2; and in the presence of lymph node metastases, for MIR107, MIR1258, MIR-137, and MIR-339. Tumors not expressing the progesterone receptor (PR) had a higher methylation level of MIR137 and MIR339. Conclusion. The study determined new molecular indicators for breast cancer progression and identified biomarkers that may be used in the differential diagnosis of breast cancer molecular subtype.

scholarly journals Assessing Gene Expression and Methylation of KMT2D and IGF2 Genes in Patients with Non-Small Cell Lung Cancer

2018 ◽  
Vol 7 (1) ◽  
pp. 55
Author(s):  
Arash Matin Ahmadi ◽  
Hessamodin Ghasemi ◽  
Sajad Nooshin ◽  
Zoofa Zayani ◽  
Shohreh Zare Karizi ◽  
...  
Keyword(s):  
Gene Expression ◽  
Lung Cancer ◽  
Methylation Level ◽  
Cpg Islands ◽  
Regulation Of Gene Expression ◽  
Tumor Development ◽  
Gene Promoter ◽  
Cancer Tissue ◽  
Lung Carcinogenesis ◽  
Igf2 Gene

Background: Aberrant promoter methylation of CpG islands is an important mechanism for regulation of gene expression. Recent data suggest that epigenetic abnormalities may occur very early in lung carcinogenesis. Systemic methylation changes may be a diagnostic marker for tumor development or prognosis. In this study, the expression and methylation of KMT2D and IGF2 genes were investigated in the lung cancer tissue compared to the adjacent normal tissue.Methods: The status of methylation of KMT2D and IGF2 genes were investigated in 30 patients with NSCLC after genomic DNA extraction using bisulfite treatment and MS-HRM method and the expression of these genes were checked by Real-Time PCR method in same samples.Results: For KMT2D gene, the expression and methylation level increased in 46.6% and 6.67% (respectively) for tumor samples comparison with normal samples (P>0.05). Also, for IGF2 gene 50% tumor samples overexpressed and 50% tumor samples showed that reduced expression comparison with the normal samples (P>0.05). In addition, 96.66% of tumor tissues did not show any change in methylation level for IGF2 gene promoter (P>0.05).Conclusion: This study showed that expression and methylation level of KMT2D and IGF2 genes did not change in NSCLC tumor samples compared to normal samples. However, this study was designed as a pilot study, and further investigations are required to confirm our findings.

scholarly journals Detection of aberrantly methylated tumor suppressor genes in breast cancer patients as a potential diagnostic biomarker

2021 ◽  
Author(s):  
Dejuan Yang ◽  
Yue Wu ◽  
Qin Xiang ◽  
Dishu Zhou ◽  
Zhu Qiu ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Tumor Suppressor ◽  
Cancer Patients ◽  
Tumor Suppressor Genes ◽  
Hormone Receptors ◽  
Methylation Status ◽  
Cancer Tissue ◽  
Aberrant Methylation ◽  
Suppressor Genes ◽  
Significant Difference

Abstract Background: Aberrant methylation of tumor suppressor genes is a common feature of breast cancer. Identifying a panel of methylated genes that are sensitive and specific for breast cancer could help to diagnose and predict prognosis of breast cancer.Methods: We determined the methylation status of DACT1, PAX5, PLCD1, ZNF545 and TET1 in 32 benign controls, 237 cancer tissue samples and 33 paired plasma samples.Results: PAX5 and PLCD1 showed exceedingly high methylation rates with percentages of 69.2% and 54.9%, whereas the methylation percentage of DACT1, ZNF545 and TET1 were 33.8%, 28.7% and 18.2% in cancer samples, respectively. A better survival of patients with ZNF545 methylation (p = 0.0350) was detected. Correlation of promoter methylation and clinicopathological features in 32 individuals with benign disease and 237 cancer patients demonstrated that methylated status of DACT1 (p=0.012), PLCD1 (p=0.013), and ZNF545 (p=0.012) had significant difference in age, and the methylation of PAX5 (p=0.006) was correlated with absence of hormone receptors, which implied an adverse outcome. PAX5 and PLCD1 both had high sensitivity (69.20% and 54.85%, respectively) and high specificity (87.50% and 100.00%, respectively). Patients with methylation of PAX5 likely to have a higher risk of breast cancer (OR=15.726, 95% CI=5.323-46.463, p<0.001), and statistical analysis of public online database showed the similar results. Conclusion: PAX5, PLCD1, ZNF545 and TET1 may serve as new potential diagnostic and prognostic biomarkers for breast cancer.

scholarly journals The BIRC Family Genes Expression in Patients with Triple Negative Breast Cancer

2021 ◽  
Vol 22 (4) ◽  
pp. 1820
Author(s):  
Anna Makuch-Kocka ◽  
Janusz Kocki ◽  
Anna Brzozowska ◽  
Jacek Bogucki ◽  
Przemysław Kołodziej ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Gene Expression ◽  
Clinical Data ◽  
Triple Negative Breast Cancer ◽  
Triple Negative ◽  
Lymphatic Vessels ◽  
The Cancer Genome Atlas ◽  
Expression Level ◽  
Cancer Tissue ◽  
Expression Levels

The BIRC (baculoviral IAP repeat-containing; BIRC) family genes encode for Inhibitor of Apoptosis (IAP) proteins. The dysregulation of the expression levels of the genes in question in cancer tissue as compared to normal tissue suggests that the apoptosis process in cancer cells was disturbed, which may be associated with the development and chemoresistance of triple negative breast cancer (TNBC). In our study, we determined the expression level of eight genes from the BIRC family using the Real-Time PCR method in patients with TNBC and compared the obtained results with clinical data. Additionally, using bioinformatics tools (Ualcan and The Breast Cancer Gene-Expression Miner v4.5 (bc-GenExMiner v4.5)), we compared our data with the data in the Cancer Genome Atlas (TCGA) database. We observed diverse expression pattern among the studied genes in breast cancer tissue. Comparing the expression level of the studied genes with the clinical data, we found that in patients diagnosed with breast cancer under the age of 50, the expression levels of all studied genes were higher compared to patients diagnosed after the age of 50. We observed that in patients with invasion of neoplastic cells into lymphatic vessels and fat tissue, the expression levels of BIRC family genes were lower compared to patients in whom these features were not noted. Statistically significant differences in gene expression were also noted in patients classified into three groups depending on the basis of the Scarff-Bloom and Richardson (SBR) Grading System.

Comparison of the Results of PCR Analysis of Gene Expression in Breast Cancer Tissue Specimens Stabilized in Formalin and RNAlater

2014 ◽  
Vol 156 (4) ◽  
pp. 486-490 ◽  
Author(s):  
N. A. Khaustova ◽  
D. S. Makeeva ◽  
O. V. Kondrashina ◽  
N. N. Fedotov ◽  
I. N. Nechaev ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Gene Expression ◽  
Breast Cancer Tissue ◽  
Pcr Analysis ◽  
Cancer Tissue ◽  
Tissue Specimens ◽  
Comparison Of The Results

scholarly journals PAX5 expression associates with survival in triple negative breast cancer.

2021 ◽  
Author(s):  
Shahan Mamoor
Keyword(s):  
Breast Cancer ◽  
Gene Expression ◽  
Cancer Patients ◽  
Triple Negative Breast Cancer ◽  
Microarray Data ◽  
Triple Negative ◽  
Molecular Subtype ◽  
Breast Cancer Patients ◽  
Primary Tumors ◽  
Significant Gene

We mined published microarray data (1) to understand the most significant gene expression differences in the tumors of triple negative breast cancer patients based on survival following treatment: dead or alive. We observed significant transcriptome-wide differential expression of paired box 5, encoded by PAX5 when comparing the primary tumors of triple negative breast cancer patients dead or alive. Importantly, PAX5 expression was significantly correlated with overall survival in basal subtype breast cancer, a molecular subtype sharing significant overlap with triple negative breast cancer. PAX5 may be of relevance as a biomarker or as a molecule of interest in understanding the etiology or progression of triple negative breast cancer.

scholarly journals The Emerging Role of ATP-Dependent Chromatin Remodeling in Memory and Substance Use Disorders

2020 ◽  
Vol 21 (18) ◽  
pp. 6816
Author(s):  
Alberto J. López ◽  
Julia K. Hecking ◽  
André O. White
Keyword(s):  
Gene Expression ◽  
Substance Use ◽  
Substance Use Disorders ◽  
Chromatin Remodeling ◽  
Cell Function ◽  
Regulation Of Gene Expression ◽  
Memory Formation ◽  
Epigenetic Mechanism ◽  
Chromatin Remodelers ◽  
Histone Modifying Enzymes

Long-term memory formation requires coordinated regulation of gene expression and persistent changes in cell function. For decades, research has implicated histone modifications in regulating chromatin compaction necessary for experience-dependent changes to gene expression and cell function during memory formation. Recent evidence suggests that another epigenetic mechanism, ATP-dependent chromatin remodeling, works in concert with the histone-modifying enzymes to produce large-scale changes to chromatin structure. This review examines how histone-modifying enzymes and chromatin remodelers restructure chromatin to facilitate memory formation. We highlight the emerging evidence implicating ATP-dependent chromatin remodeling as an essential mechanism that mediates activity-dependent gene expression, plasticity, and cell function in developing and adult brains. Finally, we discuss how studies that target chromatin remodelers have expanded our understanding of the role that these complexes play in substance use disorders.

Prognostic value of Ki67 analysed by cytology or histology in primary breast cancer

2018 ◽  
Vol 71 (9) ◽  
pp. 787-794 ◽  
Author(s):  
Stephanie Robertson ◽  
Gustav Stålhammar ◽  
Eva Darai-Ramqvist ◽  
Mattias Rantalainen ◽  
Nicholas P Tobin ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Gene Expression ◽  
Overall Survival ◽  
Survival Data ◽  
Prognostic Value ◽  
Molecular Subtype ◽  
Axillary Lymph Node Metastasis ◽  
Axillary Lymph ◽  
Poor Overall Survival ◽  
Breast Tumours

AimsThe accuracy of biomarker assessment in breast pathology is vital for therapy decisions. The therapy predictive and prognostic biomarkers oestrogen receptor (ER), progesterone receptor, HER2 and Ki67 may act as surrogates to gene expression profiling of breast cancer. The aims of this study were to investigate the concordance of consecutive biomarker assessment by immunocytochemistry on preoperative fine-needle aspiration cytology versus immunohistochemistry (IHC) on the corresponding resected breast tumours. Further, to investigate the concordance with molecular subtype and correlation to stage and outcome.MethodsTwo retrospective cohorts comprising 385 breast tumours with clinicopathological data including gene expression-based subtype and up to 10-year overall survival data were evaluated.ResultsIn both cohorts, we identified a substantial variation in Ki67 index between cytology and histology and a switch between low and high proliferation within the same tumour in 121/360 cases. ER evaluations were discordant in only 1.5% of the tumours. From cohort 2, gene expression data with PAM50 subtype were used to correlate surrogate subtypes. IHC-based surrogate classification could identify the correct molecular subtype in 60% and 64% of patients by cytology (n=63) and surgical resections (n=73), respectively. Furthermore, high Ki67 in surgical resections but not in cytology was associated with poor overall survival and higher probability for axillary lymph node metastasis.ConclusionsThis study shows considerable differences in the prognostic value of Ki67 but not ER in breast cancer depending on the diagnostic method. Furthermore, our findings show that both methods are insufficient in predicting true molecular subtypes.

Epigenetic aspects of triple-negative in patients with breast cancer.

2012 ◽  
Vol 30 (15_suppl) ◽  
pp. 1041-1041
Author(s):  
Joaquina Martínez-Galan ◽  
Sandra Rios ◽  
Juan Ramon Delgado ◽  
Blanca Torres-Torres ◽  
Jesus Lopez-Peñalver ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Gene Expression ◽  
Dna Methylation ◽  
Triple Negative ◽  
Breast Cancer Subtype ◽  
Regulation Of Gene Expression ◽  
Breast Cancer Subtypes ◽  
Luminal A ◽  
Cancer Subtypes ◽  
Luminal B

1041 Background: Identification of gene expression-based breast cancer subtypes is considered a critical means of prognostication. Genetic mutations along with epigenetic alterations contribute to gene-expression changes occurring in breast cancer. However, the reproducibility of differential DNA methylation discoveries for cancer and the relationship between DNA methylation and aberrant gene expression have not been systematically analysed. The present study was undertaken to dissect the breast cancer methylome and to deliver specific epigenotypes associated with particular breast cancer subtypes. Methods: By using Real Time QMSPCR SYBR green we analyzed DNA methylation in regulatory regions of 107 pts with breast cancer and analyzed association with prognostics factor in triple negative breast cancer and methylation promoter ESR1, APC, E-Cadherin, Rar B and 14-3-3 sigma. Results: We identified novel subtype-specific epigenotypes that clearly demonstrate the differences in the methylation profiles of basal-like and human epidermal growth factor 2 (HER2)-overexpressing tumors. Of the cases, 37pts (40%) were Luminal A (LA), 32pts (33%) Luminal B (LB), 14pts (15%) Triple-negative (TN), and 9pts (10%) HER2+. DNA hypermethylation was highly inversely correlated with the down-regulation of gene expression. Methylation of this panel of promoter was found more frequently in triple negative and HER2 phenotype. ESR1 was preferably associated with TN(80%) and HER2+(60%) subtype. With a median follow up of 6 years, we found worse overall survival (OS) with more frequent ESR1 methylation gene(p>0.05), Luminal A;ESR1 Methylation OS at 5 years 81% vs 93% when was ESR1 Unmethylation. Luminal B;ESR1 Methylation 86% SG at 5 years vs 92% in Unmethylation ESR1. Triple negative;ESR1 Methylation SG at 5 years 75% vs 80% in unmethylation ESR1. HER2;ESR1 Methylation SG at 5 years was 66.7% vs 75% in unmethylation ESR1. Conclusions: Our results provide evidence that well-defined DNA methylation profiles enable breast cancer subtype prediction and support the utilization of this biomarker for prognostication and therapeutic stratification of patients with breast cancer.

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