Genes In Breast Carcinoma Research Articles

Bioinformatic analysis and experimental validation of six cuproptosis-associated genes as a prognostic signature of breast cancer.

Breast carcinoma (BRCA) is a life-threatening malignancy in women and shows a poor prognosis. Cuproptosis is a novel mode of cell death but its relationship with BRCA is unclear. This study attempted to develop a cuproptosis-relevant prognostic gene signature for BRCA. Cuproptosis-relevant subtypes of BRCA were obtained by consensus clustering. Differential expression analysis was implemented using the 'limma' package. Univariate Cox and multivariate Cox analyses were performed to determine a cuproptosis-relevant prognostic gene signature. The signature was constructed and validated in distinct datasets. Gene set variation analysis (GSVA) and gene set enrichment analysis (GSEA) were also conducted using the prognostic signature to uncover the underlying molecular mechanisms. ESTIMATE and CIBERSORT algorithms were applied to probe the linkage between the gene signature and tumor microenvironment (TME). Immunotherapy responsiveness was assessed using the Tumor Immune Dysfunction and Exclusion (TIDE) web tool. Real-time quantitative PCR (RT-qPCR) was performed to detect the expressions of cuproptosis-relevant prognostic genes in breast cancer cell lines. Thirty-eight cuproptosis-associated differentially expressed genes (DEGs) in BRCA were mined by consensus clustering and differential expression analysis. Based on univariate Cox and multivariate Cox analyses, six cuproptosis-relevant prognostic genes, namely SAA1, KRT17, VAV3, IGHG1, TFF1, and CLEC3A, were mined to establish a corresponding signature. The signature was validated using external validation sets. GSVA and GSEA showed that multiple cell cycle-linked and immune-related pathways along with biological processes were associated with the signature. The results ESTIMATE and CIBERSORT analyses revealed significantly different TMEs between the two Cusig score subgroups. Finally, RT-qPCR analysis of cell lines further confirmed the expressional trends of SAA1, KRT17, IGHG1, and CLEC3A. Taken together, we constructed a signature for projecting the overall survival of BRCA patients and our findings authenticated the cuproptosis-relevant prognostic genes, which are expected to provide a basis for developing prognostic molecular biomarkers and an in-depth understanding of the relationship between cuproptosis and BRCA.

Pan-cancer analysis identified OAS1 as a potential prognostic biomarker for multiple tumor types.

2',5'-oligoadenylate synthetase 1 (OAS1), has been reported as a tumor driver gene in breast carcinoma and pancreatic carcinoma. However, the role of OAS1 in most tumors has not been reported. The original data of 35 tumor types were down load from the TCGA (The Cancer Genome Atlas) database and Human Protein Atlas (HPA) database. TIMER2, Kmplot, UALCAN, and TISIDB tools were used to investigate the expression and function of OAS1, and the role of OAS1 in prognosis, diagnostic value, and immune characteristics of pan-cancer. LUAD and PRAD cell lines, A549, H1975, PC-3 and C4-2 were utilized to perform cell function tests. OAS1 expression was up-regulated in 12 tumor types and down-regulated in 2 tumor types. High OAS1 expression was correlated with poor prognosis in 6 tumor types, while high OAS1 expression was correlated with good prognosis in 2 tumor types. OAS1 was correlated with molecular subtypes in 8 tumor types and immune subtypes in 12 tumor types. OAS1 was positively associated with the expression of numerous immune checkpoint genes and tumor mutational burden (TMB). OAS1 had potential diagnostic value in 15 tumor types. Silence of OAS1 significantly inhibited the cell proliferation ability, and promoted G2/M cell cycle arrest of LUAD and PRAD cells. Meanwhile, silence of OAS1 enhanced cisplatin-induced apoptosis of LUAD and PRAD cells, but weakened cell migration. This pan-cancer study suggests that OAS1can be used as a molecular biomarker for prognosis in pan-cancer and may play an important role in tumor immune response.

Kallikrein-Related Peptidase 12 (KLK12) in Breast Cancer as a Favorable Prognostic Marker.

Kallikrein-related peptides (KLKs) form an evolutionally conserved subgroup of secreted serine proteases that consists of 15 members (KLK1-15). Previous studies have shown that KLKs regulate diverse biological processes, but the clinical significance of KLKs remains largely unclear in human breast cancers. We examined the expression profile of 15 KLK genes in breast carcinomas using microarray data. Next, we immunolocalized KLK12 in 140 breast carcinomas and evaluated its clinical significance. Subsequently, we examined the effects of KLK12 on proliferation and migration in breast cancer cell lines. From microarray analyses, it turned out that KLK12 was the most strongly associated with low-grade malignancy in breast carcinomas among the 15 KLK members. Immunohistochemical KLK12 status was positively associated with ER and PR status, while it was inversely associated with stage, pathological T factor, lymph node metastasis, and distant metastasis. Prognostic analyses demonstrated that KLK12 was a favorable prognostic factor for both disease-free and breast cancer-specific survival of the patients. Furthermore, the knockdown of KLK12 significantly increased cell proliferation activity and cell migration of breast cancer cells. These results suggest that KLK12 has antitumorigenic effects associated with proliferation and migration and immunohistochemical KLK12 status as a potent favorable prognostic factor in breast carcinoma patients.

Abstract P2-18-02: Promoter hypomethylation associated upregulation of MEN1 mRNA expression and its correlation with pathological parameters in Indian breast cancer patients

Abstract Background: Breast cancer in the recent years has accounted to be most frequently reported cancer across the globe. Nearly 11.7% of total cancer cases were of breast cancer and 6,84,996 deaths were reported in the year 2020. Multiple endocrine neoplasia type 1 gene that encodes for menin protein is known be involved in numerous signaling pathways and is also reported to show its interactions with histone modifiers. MEN1 is frequently reported to be dysregulated in the cancer including neuroendocrine tumors, lung cancer and melanoma. However, the role of MEN1 in case of Breast cancer has not been well understood. Lifestyle, environmental conditions and ethnicity play crucial role in epigenetic modulation of gene expression. In the current scenario with high increase in number of cancer cases, there is need to develop more personalized course of treatment rather than generalized approach. Thus, discovery of new biomarkers will aid in designing better diagnostic and therapeutic strategy to treat cancer. Aims and Objective: In this study we aim to find MEN1 mRNA expression and its connection with the MEN1 promoter methylation in case of Indian breast cancer patients and to correlate our findings with the pathological parameters of the patients to understand the role of MEN1 gene in breast cancer progression. Material and methods: The ethical approval for the study was procured from Institutional ethical committee of AIIMS,New Delhi and Jamia Millia Islamia, New Delhi. The study comprises of 44 pair of Breast tissue samples including cancer and adjacent normal tissue collected at department of surgical oncology AIIMS, New Delhi and were stored in RNA later and PBS at -80˚C for RNA and DNA extraction respectively. DNA was extracted through PCI (Phenol-Chloroform-Isoamyl alcohol) method and was further confirmed by Agarose gel electrophoresis. TRIZOL method was used to extract RNA from tissue samples and was quantified using nanodrop. Moreover, cDNA synthesis was carried out using Verso cDNA synthesis kit. To investigate the MEN1 mRNA expression, RT- PCR was carried out with LightCycler96 SYBR Green I Master (Roche) using specific primers. To analyze the promoter methylation status of MEN1 promoter region, CT- conversion was done and MS-PCR was performed using Methylation and Unmethylation specific primers. Statistical analysis was done using Graph Pad and SPSS to correlate our findings with clinical parameters. Results: In our study we found 27 out of 44 patients to exhibit up-regulation of MEN1 mRNA in the breast cancer tissue as compared with the normal tisuue. MEN1 promoter unmethylation was detected in 25 out of 44 cases, which revealed its significant correlation with the upregulated MEN1 gene. Further on correlation of our data with the clinical parameters, we found its significant association with the estrogen receptor status and age of menopause of the patients. Conclusion: Our results of the MEN1 mRNA expression study and its association with MEN1 promoter methylation in case of breast cancer suggests the tumorigenic role of MEN1 in breast cancer. Our findings thereby indicate the possible role of MEN1 gene in progression of the disease. Further study on large sample size will aid in better understanding the role of MEN1 gene in Breast carcinoma. Citation Format: Sheersh Massey, Aasif Khan, Asifa Khan, SVS Deo, Syed Akhtar Husain. Promoter hypomethylation associated upregulation of MEN1 mRNA expression and its correlation with pathological parameters in Indian breast cancer patients [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P2-18-02.

The lncRNA GATA3-AS1/miR-495-3p/CENPU axis predicts poor prognosis of breast cancer via the PLK1 signaling pathway

The function of centromere protein U (CENPU) gene in breast cancer has not been well understood. Therefore, we explored the expression profiles of CENPU gene in breast carcinoma to better understand the functions of this gene, as well as the relationship between CENPU expression and the prognosis of breast carcinoma patients. Our results indicate that CENPU was expressed at significantly higher levels in cancerous tissues than in normal tissues. Furthermore, CENPU expression correlated significantly with many clinicopathological characteristics of breast cancer. In addition, we discovered that high levels of CENPU expression predicted poor prognosis in patients with breast cancer. Functional investigation revealed that 180 genes exhibited co-expression with CENPU. Functional annotation indicated that 17 of these genes were involved in the PLK1 signaling pathway, with most of them (16/17) being expressed at significantly higher levels in malignant tissues compared with normal controls and correlating with a poor prognosis. Subsequently, we found that four miRNAs, namely hsa-miR-543, hsa-miR-495-3p, hsa-miR-485-3p, and hsa-miR-337-3p, could be regarded as potential CENPU expression regulators. Then, five lncRNAs were predicted to potentially bind to the four miRNAs. Combination of the results from expression, survival, correlation analysis and functional experiments analysis demonstrated the link between lncRNA GATA3-AS1/miR-495-3p/CENPU axis and prognosis of breast cancer. In conclusion, CENPU could be involved in cell cycle progression through PLK1 signaling pathway.

Differential Expression and Prognostic Significance of STARD3 Gene in Breast Carcinoma.

StAR related lipid transfer domain containing 3 (STARD3) gene has been reported to be co-amplified with human epidermal growth factor receptor 2 (HER2) in breast carcinoma. STARD3 is necessary for cholesterol transfer and metabolism in tumor cells. The possible role played by STARD3 as a diagnostic and prognostic biomarker was investigated in breast cancer (BC). Data mining was performed using several bioinformatics websites to investigate the correlation of STARD3 with BC and its molecular subtypes, and conventional PCR was used to detect the STARD3 mRNA levels in a panel of BC cell lines. STARD3 was overexpressed in BC more than the other types of cancer. The results also showed that STARD3 expression was significantly associated with HER2+ BC tumors and BC cell lines, and low STARD3 mRNA and protein expression levels were observed in estrogen receptor-positive (ER+) and triple-negative BC (TNBC) patients. Moreover, high STARD3 expression levels predicted worse overall survival (OS), relapse-free survival (RFS) and disease metastasis-free survival (DMFS) in BC, and HER2+ BC. Notably, low expression of STARD3 was associated with poor OS in ER+ BC. Our findings suggest that STARD3 may have strong diagnostic and prognostic value for HER2+ breast carcinoma.

Abstract 2058: Augmenting the My Cancer Genome knowledge resource with data from AACR Project GENIE

Abstract My Cancer Genome (https://www.mycancergenome.org; MCG) recently released a major update to the website, with an ultimate goal of adding of AACR Project GENIE data to demonstrate frequency of genetic variants in cancer, estimate matching to clinical trial arms, and augment the case report database. This abstract presents use of GENIE data 1) as part of a new process to automatically select cancer types and biomarkers for inclusion and 2) to display prevalence data on the website. My Cancer Genome is a publicly available precision cancer medicine knowledgebase managed by the Vanderbilt-Ingram Cancer Center. The mission of MCG is to curate and disseminate knowledge regarding the clinical significance of genomic alterations in cancer. The website was first made available to the public in early 2011 and has since grown into a resource visited more than 7,000 times a week by people from well over 200 countries and territories around the world. The new website was released in June 2019, and it includes several new features: a new clinical trials search using manually curated disease and biomarker eligibility criteria, therapeutic assertions illustrating situations where having or not having a particular biomarker detected supports or does not support use of a particular drug, and the inclusion of data from AACR Project GENIE. Addition of GENIE data to MCG was approved by AACR Project GENIE's Data Use and Publications Committee. First, any disease or biomarker associated with a therapeutic assertion or clinical trial has a page on MCG. In addition, any disease or biomarker that appears five times or more in the GENIE dataset is also given a page. In this way, the website will remain up-to-date with almost all diseases and biomarkers that can be considered relevant as precision oncology knowledge and GENIE grow. Next, GENIE data appears on disease and biomarker pages, in both charts and descriptive text. On disease pages, such as the breast carcinoma page, GENIE data appear in a chart of most commonly altered genes in breast carcinoma and most common alterations in breast carcinoma; in addition, text describing the prevalence of mutations appears under each gene listed in the section on significant genes in breast carcinoma. On biomarker pages, such as the ABL1 page, GENIE data appear in a chart of the most common diseases where ABL1 has been found to be altered and the most common alterations in ABL1 that appear in GENIE cases; in addition, text describing the prevalence of ABL1 mutations appears under each disease listed in the section on the significance of ABL1 in diseases. The addition of data from AACR Project GENIE to My Cancer Genome has improved and enhanced MCG's content, ability to scale, and ability to maintain. Finally, inclusion of data from AACR Project GENIE on My Cancer Genome provides a simple way to select and view subsets of GENIE data for specific diseases and biomarkers in the context of relevant precision oncology therapies and clinical trials. Citation Format: Christine M. Micheel, Michele L. LeNoue-Newton, Marilyn E. Holt, Neha Jain, Mia A. Levy. Augmenting the My Cancer Genome knowledge resource with data from AACR Project GENIE [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 2058.

Expression of MTERF3 gene in breast carcinoma and the relationship with clinicopathological characteristics.

BackgroundMitochondrial transcription termination factor 3 (MTERF3) is a negative regulator of mitochondrial transcription. It is a modular factor involves in mitochondrial ribosome biogenesis and protein synthesis. However, the association between MTERF3 and breast cancers remains largely unknown. The aim of this study was to investigate the expression of MTERF3 in breast carcinoma and to analyze its clinicopathological significance, and to examine the potential prognostic value of MTERF3 in breast cancer.MethodsThe protein expression levels of MTERF3 in MCF7 (Luminal A), BT-474 (Luminal B), SKBR3 (HER2 overexpression), MDA-MB-468 (Basal like) and MCF10A cell lines were detected by Western blotting. Immunohistochemistry (IHC), Western blotting, and semiquantitative RT-PCR were performed to analyze the protein and mRNA expression levels of MTERF3 in 58 breast cancer tissues and 58 noncancerous breast tissues. The MTERF3 expression data and clinical information from breast cancer patients were downloaded from the TCGA dataset by using the R3.6.1 software. Then the relationship between the expression level of MTERF3 and clinicopathological characteristics and the prognostic value was analyzed. A Cox regression model was performed for the multivariate analysis of the factors that affected the prognosis of breast cancer. The association between the expression levels of MTERF3 and other mitochondrial regulatory genes was analyzed with GEPIA.ResultsMTERF3 is upregulated in breast cancer cell lines compared to noncancerous breast cell line. The IHC results showed that the MTERF3 protein was located in the cytoplasm, and the rate of positive expression in breast cancer tissue was significantly upregulated compared with the adjacent normal tissue. The mRNA and protein expression levels of MTERF3 in breast cancer tissues were significantly higher than that in breast tissues. Moreover, the expression of MTERF3 was significantly correlated with ER status, PR status, breast cancer molecular typing, cancer type, histological diagnosis and primary site (P<0.05). Further analysis showed MTERF3 expression was not related to prognosis. Multivariate Cox regression analysis showed that age, metastasis status and tumor type were independent prognostic factors for breast cancer patients. The expression levels of MTERF3 were positively correlated with the TFAM, TFB1M, TFB2M, MTERF1, TEFM and MFN1 genes but negatively correlated with the MTERF4 and PINK1 genes. In addition, the expression levels of MTERF3 were not correlated with the MTERF2 gene.ConclusionsMTERF3 was significantly upregulated in breast cancer cells and tissues compared with noncancerous cells and tissues. Moreover, the expression level of MTERF3 was correlated with ER status, PR status, breast cancer molecular typing, cancer type, histological diagnosis and primary site. These findings suggested that the upregulation of MTERF3 may be used as a diagnostic and therapeutic target in breast carcinoma.

An overview of cancer genetics with focus on involvement of BRCA1/2 genes in breast carcinomas

Cancer is a kind of disease which can be explained at the molecular level as triggered by accretion of damaged deoxyribonucleic acid. There are several genes involved in cancer, mainly belonging to two classes called tumour suppressors and oncogenes. Other than the well-known breast cancer susceptibility 1/2 genes, there are several other genes involved in the development of breast and ovarian cancers. However, since the past two decades the focus of research has been on and breast cancer susceptibility 1/2 genes. The current review was planned to delve into the structure and function of breast cancer susceptibility 1/2 genes to augment research on the genetics of breast cancer. The understanding of tumour suppressor genes is also helpful in the analysis of mutational spectra and to determine the treatment strategies in clinical interventional studies.

Radiosensitizing effects of Sestrin2 in PC3 prostate cancer cells.

Objective(s):The stress-responsive genes of Sestrin family are recognized as new tumor suppressor genes in breast carcinoma, however, the function of Sestrin family in human prostate cancer is not clear. Ionizing radiation (IR) is known to induce Sestrin gene expression in breast cancer cells. However, the response of Sestrin to IR has not been reported in PC3 prostate cancer cells.Materials and Methods:Sestrin2 expression in prostate cancer cell lines (PC3, LNCaP clone FGC, and DU145) was detected by Western blot and real-time PCR. Cell counting kit (CCK-8) was used to detect cellular proliferation. The radiosensitivity of PC3 cells was detected by clonogenic assay.Results:Sestrin2 expression in prostate cancer cell lines (PC3, LNCaP clone FGC, and DU145) is low. In vitro assays indicated that over-expressing Sestrin2 in human prostate cancer PC3 inhibited tumor proliferation. In addition, elevated Sestrin2 expression sensitized PC3 cells to IR.Conclusion:We determined Sestrin2 may function as a tumor suppressor through repressing proliferation, mediating sensitization to IR in PC3 cells.

Expression of ERβ gene in breast carcinoma and the relevance in neoadjuvant therapy

In the present study, we examined the expression of the estrogen receptor β (ERβ) gene in breast cancer and its relevance in neoadjuvant therapy. In total, 120 breast cancer patients who were hospitalized in the Departments of Breast Disease and Medical Oncology served as the subjects of this study. The subjects were diagnosed with breast cancer phase II to phase IIIA, as confirmed by aspiration biopsy and iconography. The patients were divided into two groups in a randomized control manner, with 60 patients in each group. The experimental group was administered the taxotere + epirubicin + cyclophosphamide (TEC) plan for 3–4 cycles of chemotherapy before the modified radical operation of breast cancer. In the control group, no TEC chemotherapy was carried out prior to operation. Instead, the breast lesion was removed directly by operation. After the operation, the IHC method was used to stain the ERβ protein in the lesion tissue. The patients were classified according to whether the basement membrane was broken through; 5 cases had non-infiltrative carcinoma and 115 cases had infiltrative carcinoma. According to the pathology of the lesion, 114 cases had breast ductal carcinoma, 2 cases had mucinous breast carcinoma (of which there were 2 cases combined with ductal carcinoma), and 4 cases had breast lobular carcinoma. The ERβ gene was found to be expressed in normal and breast cancer tissues. When ERβ gene expression was compared before and after the chemotherapy, its expression was significantly increased in breast cancer tissues, which shows a significant statistical difference (P<0.05). In the experimental group, the expression of ERβ gene in carcinoma tissue was significantly lower than that in the control group, and differences were statistically significant (P<0.05). Therefore, expression of the ERβ gene in breast carcinoma tissues was high. The application of adjuvant chemotherapy before the modified radical operation for breast carcinoma can significantly lower the level of ERβ expression. The expression levels of ERβ gene in the carcinoma tissue of the patients can be treated as the evaluation index for neoadjuvant chemotherapy. Regarding targeted therapy and corresponding drug development for breast carcinoma, ERβ can act as one of the specific drug targets.

Hyaluronate synthase-2 overexpression alters estrogen dependence and induces histone deacetylase inhibitor-like effects on ER-driven genes in MCF7 breast tumor cells

In breast carcinoma cells, high levels of hyaluronan (HA) and its CD44 receptor are frequently associated with alteration in estrogen signaling. We demonstrate that stable hyaluronate synthase 2 (HAS2) overexpression in estrogen receptor α (ERα) -positive MCF7 cells oppositely altered estrogen dependence of cell growth and its sensitivity towards antiestrogens. Albeit without effect on ERα expression and estradiol binding properties, HAS2 overexpression increased ERα Ser118 phosphorylation as well as transcriptional activity of estrogen in an ERE-luciferase reporter gene assay. However, HAS2 overexpression induced partial silencing of E2 driven-genes without affecting the magnitude of regulation by estradiol. This effect was associated with half-reduction in the activity of nuclear histone deacetylases (HDACs) through a post-translational mechanism likely consecutive to the enhanced expression of the histone acetyl-transferase EP300. In conclusion, increase in HA/CD44 interactions may contribute, through an HDAC inhibitor-like and ER-independent mechanism, to the silencing of estrogen–driven genes in breast carcinoma.

Association of breast cancer risk with genetic variants showing differential allelic expression: Identification of a novel breast cancer susceptibility locus at 4q21.

There are significant inter-individual differences in the levels of gene expression. Through modulation of gene expression, cis-acting variants represent an important source of phenotypic variation. Consequently, cis-regulatory SNPs associated with differential allelic expression are functional candidates for further investigation as disease-causing variants. To investigate whether common variants associated with differential allelic expression were involved in breast cancer susceptibility, a list of genes was established on the basis of their involvement in cancer related pathways and/or mechanisms. Thereafter, using data from a genome-wide map of allelic expression associated SNPs, 313 genetic variants were selected and their association with breast cancer risk was then evaluated in 46,451 breast cancer cases and 42,599 controls of European ancestry ascertained from 41 studies participating in the Breast Cancer Association Consortium. The associations were evaluated with overall breast cancer risk and with estrogen receptor negative and positive disease. One novel breast cancer susceptibility locus on 4q21 (rs11099601) was identified (OR = 1.05, P = 5.6x10-6). rs11099601 lies in a 135 kb linkage disequilibrium block containing several genes, including, HELQ, encoding the protein HEL308 a DNA dependant ATPase and DNA Helicase involved in DNA repair, MRPS18C encoding the Mitochondrial Ribosomal Protein S18C and FAM175A (ABRAXAS), encoding a BRCA1 BRCT domain-interacting protein involved in DNA damage response and double-strand break (DSB) repair. Expression QTL analysis in breast cancer tissue showed rs11099601 to be associated with HELQ (P = 8.28x10-14), MRPS18C (P = 1.94x10-27) and FAM175A (P = 3.83x10-3), explaining about 20%, 14% and 1%, respectively of the variance inexpression of these genes in breast carcinomas.

STUDY ON TRANSCRIPTION POSSIBILITY OF EPIDERMAL GROWTH FACTOR RECEPTOR (EGFR) GENE IN BREAST CARCINOMA TISSUES BY REVERSE TRANSCRIPTION-PCR ASSAY

Background: EGFR is a member of the EGFR family- type I transmembrane tyrosine kinase receptors, which plays an essential role in development and growth of body. However, EGFRs are frequently overexpressed, this overexpression and its signal pathway induce unrestricted development and uncontrolled proliferation in human malignant tumors including breast carcinoma, one of the most common cancer in women. Objective: (1)To evaluate transcript level of EGFR gene in breast carcinoma tissues by RT-PCR assay.(2)To compare transcript level of EGFR gene in breast carcinoma with breast fibro adenoma. Subject and Methods: total RNA from 70 samples including 38 breast carcinoma tissues and 32 breast fibroadenoma tissues were extracted. EGFR transcript level were determined using semi-quantitative Reverse Transcription-PCR assay. PCR products were tested by electrophoresis on agarose gel 2%. Results: RNA total concentration in breast carcinoma tissues was 170.03 ± 201.17 ng/µl, was significantly higher in breast fibro adenoma tissue: 65.96 ± 43.16 ng/µl (p&lt;0.05). EGFR transcript level was highly expressed in breast carcinoma compared to breast fibro adenoma (1.22 ± 0.24 compared to 0.75 ± 0,19) (p&lt; 0.0001). The cut-off point of the rate EGFR/GAPDH was 0.97, area under the curve: 0.913, p&lt; 0.0001, sensitivity and specificity were 81,58% and 93.75%. Conclusion: Transcript level of EGFR gene in breast carcinoma was significantly 1.63 times higher than in breast fibro-adenoma. The cut-off point of the rate EGFR/GAPDH was 0.97, sensitivity: 81.58% and specificity: 93.75%. Key words: EGFR, RT-PCR, breast carcinoma

EMP1, a member of a new family of antiproliferative genes in breast carcinoma

This study aimed to analyze the expression, clinical significance of epithelial membrane protein 1 (EMP1) in breast carcinoma and the biological effect in its cell line by EMP1 overexpression. Immunohistochemistry and western blot were used to analyze EMP1 protein expression in 67 cases of breast cancer and 35 cases of normal tissues to study the relationship between EMP1 expression and clinical factors. Quantitative real-time RT-PCR and western blot were used to detect the mRNA level and protein of EMP1. MTT assay, migration and invasion assays were also conducted as to the influence of the upregulated expression of EMP1 that might be found on MCF-7 cell biological effect. The relative amount of EMP1 protein in breast cancer tissue was found to be significantly lower than in normal tissues (P < 0.05). The level of EMP1 protein expression was correlated with T stages, lymph node metastasis, clinic stage, and histological grade (P < 0.05). Meanwhile, loss of EMP1 expression correlated significantly with poor overall survival time by Kaplan-Meier analysis (P < 0.05). The result shown that MCF-7 cell transfected EMP1 had a lower survival fraction, higher cell apoptosis, significant decrease in migration and invasion, higher caspase-9, and lower VEGFC protein expression compared with MCF-7 cell untransfected EMP1 (P < 0.05). EMP1 expression decreased in breast cancer and correlated significantly with lymph node metastasis, clinic stage, histological grade, and poor overall survival, T stages, suggesting that EMP1 may play important roles as a negative regulator to breast cancer MCF-7 cell by regulating the expression of caspase 9 and VEGFC protein.

Expression and significance of Wnt signaling components and their target genes in breast carcinoma

The aim of this study was to investigate the expression of β-catenin, axin, cyclin D1 and c-myc, and their correlation with various clinicopathological factors of breast carcinoma. Using immunohistochemistry, the expression of axin, β-catenin, cyclin D1 and c-myc proteins was detected in 168breast carcinomas and 40normal breast tissue samples, as well as in 72breast intraductal proliferative lesions. Correlations among the expression of these proteins with the clinicopathological factors of breast carcinomas were subsequently analyzed. Gene mutations of β-catenin (exon3) in 44cases of breast carcinoma were analyzed using polymerase chain reaction (PCR) followed by direct sequencing. In normal tissue, the epithelial cells demonstrated a marked membranous expression of β-catenin protein at cell-cell boundaries and positive axin expression; cyclin D1 and c-myc expression, however, were negative. The abnormal rate of β-catenin expression and the overexpression of cyclin D1 and c-myc were higher in breast carcinomas compared with breast cystic hyperplasia tissues. Positive axin expression levels were lower in breast carcinomas compared with breast intraductal proliferative lesions and normal breast tissues. Axin expression correlated inversely with tumor size, histological grade, clinical tumor, node, metastasis (TNM) stage and lymph node metastasis. The abnormal expression of β-catenin and the overexpression of cyclin D1 were correlated, and the overexpression of c-myc was correlated with tumor size, histological grade, clinical TNM stage and lymph node metastasis. The abnormal expression of β-catenin was correlated with the overexpression of cyclin D1, but not with the overexpression of c-myc. Lower levels of axin expression were correlated with higher levels of nuclear β-catenin expression. Mutations in the β-catenin gene were not detected in 44cases of breast carcinoma. The abnormal expression of β-catenin may be key in the carcinogenesis and progression of human breast carcinoma by upregulating the expression of cyclin D1. The abnormal expression of β-catenin, the reduced expression of axin, and the overexpression of cyclin D1 and c-myc may be useful markers for determining metastasis, providing a prognosis for human breast carcinoma and for guiding treatment.

MiR-18a as a potential regulator of estrogen-related genes in human breast carcinomas

Background Estrogen receptor (ER) status has been used as a biomarker in breast carcinomas (BC), allowing the identification of tumors that may respond to ER antagonists or aromatase inhibitors. Two previous studies by our group evaluating gene and miRNA expression profiles in BC samples from Brazilian patients revealed 15 genes and 3 microRNAs as significantly associated with BC, according to ER status. The aim of this study was to evaluate the correlation between these 3 microRNAs and ER-related genes in BC.

The Expression Profile of Atp-Binding Cassette Transporter Genes in Breast Carcinoma

ATP-binding cassette (ABC) transporters contribute to development of resistance to anticancer drugs via ATP-dependent drug efflux. A major goal of our study was to investigate associations between the expression of ABC transporters and outcome of breast carcinoma patients. Transcript levels of all 49 human ABC transporters were determined in post-treatment tumor and non-neoplastic tissue samples from 68 breast carcinoma patients treated by neoadjuvant chemotherapy. Six ABC transporters were then evaluated in independent series of 100 pretreatment patients. ABCA5/6/8/9/10, ABCB1/5/11, ABCC6/9, ABCD2/4, ABCG5 and ABCG8 were significantly downregulated and ABCA2/3/7/12, ABCB2/3/8/9/10, ABCC1/4/5/10/11/12, ABCD1/3, ABCE1, ABCF1/2/3 and ABCG1 were upregulated in post-treatment tumors compared with non-neoplastic tissues. Significant associations of intratumoral levels of ABCC1 and ABCC8 with grade and expression of hormonal receptors were found in both sets of patients. ABCA12, ABCA13 and ABCD2 levels were significantly associated with the response to neoadjuvant chemotherapy in post-treatment patients. Protein expression of ABCA12, ABCC8 and ABCD2 in tumor tissues of patients with breast carcinoma was observed by immunoblotting for the first time. ABCA12, ABCA13, ABCC1, ABCC8 and ABCD2 present potential modifiers of progression and response to the chemotherapy of breast carcinoma.

Identification of novel SNPs in SYK gene of breast cancer patients: computational analysis of SNPs in the 5′UTR

Spleen tyrosine kinase (SYK) is a non receptor type tyrosine kinase and a known candidate tumor suppressor gene in breast carcinoma. Loss of Syk is associated with breast cancer invasion and increased cell mortality. The main goal of our study was to detect germ-line polymorphisms in SYK gene in breast cancer affected females of Pakistani origin, in order to understand the genetic basis of complex human breast cancer. Seven novel SYK gene SNPs were identified in breast cancer patients. Among these, three were identified in intronic region, one at the 5'splice donor site (5'SD) and three in 5'untranslated region (5'UTR) of SYK gene. Mutations at the 5'SD and at 5'UTR can be crucial and could be responsible for generation of mutated Syk protein. In silico analysis of the 5'UTR variations revealed that one of the mutations was responsible for generation of a more stable structure of 5'UTR. Such a change in pre-mRNA could potentially down regulate SYK expression. These findings add to the growing literature implicating dysfunctional SYK gene as a contributor to human breast cancer, and suggest that therapies targeting its molecular pathways could provide effective means of treating/preventing breast cancer.

Constitutional methylation of cancer-related and selenoprotein coding genes in breast carcinoma in Polish population

Recently, much attention is paid to the phenomenon of gene’s hypermethylation in the peripheral blood (PB) and its involvement in the pathology of cancer. Breast cancer is a complex disease driven by multiple factors including both genetic and epigenetic processes. Genetic changes associated with breast cancer are not completely known, but epigenetic mechanisms involved in this disease seem to play an important role in its pathophysiology. An aberrant methylation in the promoter regions of genes involved in cancer induction and promotion, like BRCA1, BRCA2, ATM, MLH1 and ESR1, may be of particular importance in breast cancer. A very interesting class of genes, involved in selenium metabolism is under investigation with respect to different kind of cancers including breast cancer. Proteins coded by these genes, e.g. glutathione peroxidases, thioredoxin reductases or other selenoproteins are involved in variety of biological processes, ranging from DNA synthesis to protection against oxidative stress and may be related to breast cancer risk. Aim of our study was to analyze methylation of genes involved in selenium metabolism (GPX1, GPX4, TXNRD1, SEP15 and SELT) and other cancer related genes (BRCA1, BRCA2, ATM, MLH1 and ESR1) in DNA isolated from PB of breast cancer patients or unaffected individuals. A study was conducted on 30 female BRCA1 mutation carriers, 30 female CHEK2 mutation carriers and 36 unselected breast cancer patients negative for recurrent Polish BRCA1/BRCA2 mutations and with specific pathological characteristics: medullary or atypical medullary breast cancer or bilateral breast cancer or ER, PGR and HER negative tumors. Methylation of BRCA1 gene was additionally analyzed in group of 36 healthy controls, age-matched to unselected breast cancer patients. Methylation analysis was done by MS-HRM technique. We observed promoter methylation of BRCA1 (20 samples), ESR1 (7 samples) and MLH1 (3 samples) genes. BRCA1 gene methylation was detected in 1 patient with CHEK2 and 4 patients with BRCA1 mutation. We found strong statistically significant difference of BRCA1 gene methylation in unselected breast cancer patients (15 patients) and unaffected age-matched controls (2 individuals): OR=12.1; p-value=0.0009. Selenoprotein coding genes GPX1 and GPX4 shows complete methylation while TXNRD1 and SELT show methylation in ~10% of the studied group.