scholarly journals Enhancers mapping uncovers phenotypic heterogeneity and evolution in patients with luminal breast cancer

2017 ◽  
Author(s):  
Darren K. Patten ◽  
Giacomo Corleone ◽  
Balázs Győrffy ◽  
Edina Erdős ◽  
Alina Saiakhova ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Progression ◽  
Regulatory Elements ◽  
Phenotypic Heterogeneity ◽  
Endocrine Treatment ◽  
Clinical Samples ◽  
Luminal Breast Cancer ◽  
Breast Cancer Patients ◽  
Expression Of Genes

AbstractThe degree of intrinsic and interpatient phenotypic heterogeneity and its role in tumour evolution is poorly understood. Phenotypic divergence can be achieved via the inheritance of alternative transcriptional programs1,2. Cell-type specific transcription is maintained through the activation of epigenetically-defined regulatory regions including promoters and enhancers1,3,4. In this work, we annotated the epigenome of 47 primary and metastatic oestrogen-receptor (ERα)-positive breast cancer specimens from clinical samples, and developed strategies to deduce phenotypic heterogeneity from the regulatory landscape, identifying key regulatory elements commonly shared across patients. Highly shared regions contain a unique set of regulatory information including the motif for the transcription factor YY1. In vitro work shows that YY1 is essential for ERα transcriptional activity and defines the critical subset of functional ERα binding sites driving tumor growth in most luminal patients. YY1 also control the expression of genes that mediate resistance to endocrine treatment. Finally, we show that H3K27ac levels at active enhancer elements can be used as a surrogate of intra-tumor phenotypic heterogeneity, and to track expansion and contraction of phenotypic subpopulations throughout breast cancer progression. Tracking YY1 and SLC9A3R1 positive clones in primary and metastatic lesions, we show that endocrine therapies drive the expansion of phenotypic clones originally underrepresented at diagnosis. Collectively, our data show that epigenetic mechanisms significantly contribute to phenotypic heterogeneity and evolution in systemically treated breast cancer patients.

scholarly journals Splicing factor SRSF1 promotes breast cancer progression via oncogenic splice switching of PTPMT1

2021 ◽  
Vol 40 (1) ◽  
Author(s):  
Jun-Xian Du ◽  
Yi-Hong Luo ◽  
Si-Jia Zhang ◽  
Biao Wang ◽  
Cong Chen ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Progression ◽  
High Risk Group ◽  
Clinical Samples ◽  
Binding Motif ◽  
Ki 67 ◽  
Tissue Samples

Abstract Background Intensive evidence has highlighted the effect of aberrant alternative splicing (AS) events on cancer progression when triggered by dysregulation of the SR protein family. Nonetheless, the underlying mechanism in breast cancer (BRCA) remains elusive. Here we sought to explore the molecular function of SRSF1 and identify the key AS events regulated by SRSF1 in BRCA. Methods We conducted a comprehensive analysis of the expression and clinical correlation of SRSF1 in BRCA based on the TCGA dataset, Metabric database and clinical tissue samples. Functional analysis of SRSF1 in BRCA was conducted in vitro and in vivo. SRSF1-mediated AS events and their binding motifs were identified by RNA-seq, RNA immunoprecipitation-PCR (RIP-PCR) and in vivo crosslinking followed by immunoprecipitation (CLIP), which was further validated by the minigene reporter assay. PTPMT1 exon 3 (E3) AS was identified to partially mediate the oncogenic role of SRSF1 by the P-AKT/C-MYC axis. Finally, the expression and clinical significance of these AS events were validated in clinical samples and using the TCGA database. Results SRSF1 expression was consistently upregulated in BRCA samples, positively associated with tumor grade and the Ki-67 index, and correlated with poor prognosis in a hormone receptor-positive (HR+) cohort, which facilitated proliferation, cell migration and inhibited apoptosis in vitro and in vivo. We identified SRSF1-mediated AS events and discovered the SRSF1 binding motif in the regulation of splice switching of PTPMT1. Furthermore, PTPMT1 splice switching was regulated by SRSF1 by binding directly to its motif in E3 which partially mediated the oncogenic role of SRSF1 by the AKT/C-MYC axis. Additionally, PTPMT1 splice switching was validated in tissue samples of BRCA patients and using the TCGA database. The high-risk group, identified by AS of PTPMT1 and expression of SRSF1, possessed poorer prognosis in the stage I/II TCGA BRCA cohort. Conclusions SRSF1 exerts oncogenic roles in BRCA partially by regulating the AS of PTPMT1, which could be a therapeutic target candidate in BRCA and a prognostic factor in HR+ BRCA patient.

scholarly journals Twist-mediated PAR1 induction is required for breast cancer progression and metastasis by inhibiting Hippo pathway

2020 ◽  
Vol 11 (7) ◽  
Author(s):  
Yifan Wang ◽  
Ruocen Liao ◽  
Xingyu Chen ◽  
Xuhua Ying ◽  
Guanping Chen ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Cells ◽  
Cancer Progression ◽  
Invasive Breast Cancer ◽  
Breast Cancer Cells ◽  
Epithelial Mesenchymal Transition ◽  
Hippo Pathway ◽  
Breast Cancer Patients ◽  
Mesenchymal Transition

Abstract Breast cancer is considered to be the most prevalent cancer in women worldwide, and metastasis is the primary cause of death. Protease-activated receptor 1 (PAR1) is a GPCR family member involved in the invasive and metastatic processes of cancer cells. However, the functions and underlying mechanisms of PAR1 in breast cancer remain unclear. In this study, we found that PAR1 is highly expressed in high invasive breast cancer cells, and predicts poor prognosis in ER-negative and high-grade breast cancer patients. Mechanistically, Twist transcriptionally induces PAR1 expression, leading to inhibition of Hippo pathway and activation of YAP/TAZ; Inhibition of PAR1 suppresses YAP/TAZ-induced epithelial-mesenchymal transition (EMT), invasion, migration, cancer stem cell (CSC)-like properties, tumor growth and metastasis of breast cancer cells in vitro and in vivo. These findings suggest that PAR1 acts as a direct transcriptionally target of Twist, can promote EMT, tumorigenicity and metastasis by controlling the Hippo pathway; this may lead to a potential therapeutic target for treating invasive breast cancer.

scholarly journals Blockade of CDK7 Reverses Endocrine Therapy Resistance in Breast Cancer

2020 ◽  
Vol 21 (8) ◽  
pp. 2974 ◽  
Author(s):  
Yasmin M. Attia ◽  
Samia A. Shouman ◽  
Salama A. Salama ◽  
Cristina Ivan ◽  
Abdelrahman M. Elsayed ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Tumor Volume ◽  
Apoptotic Cell ◽  
Therapy Resistance ◽  
Tamoxifen Treatment ◽  
Clinical Samples ◽  
Breast Cancer Cell Lines ◽  
Breast Cancer Patients

Cyclin-dependent kinase (CDK)-7 inhibitors are emerging as promising drugs for the treatment of different types of cancer that show chemotherapy resistance. Evaluation of the effects of CDK7 inhibitor, THZ1, alone and combined with tamoxifen is of paramount importance. Thus, in the current work, we assessed the effects of THZ1 and/or tamoxifen in two estrogen receptor-positive (ER+) breast cancer cell lines (MCF7) and its tamoxifen resistant counterpart (LCC2) in vitro and in xenograft mouse models of breast cancer. Furthermore, we evaluated the expression of CDK7 in clinical samples from breast cancer patients. Cell viability, apoptosis, and genes involved in cell cycle regulation and tamoxifen resistance were determined. Tumor volume and weight, proliferation marker (Ki67), angiogenic marker (CD31), and apoptotic markers were assayed. Bioinformatic data indicated CDK7 expression was associated with negative prognosis, enhanced pro-oncogenic pathways, and decreased response to tamoxifen. Treatment with THZ1 enhanced tamoxifen-induced cytotoxicity, while it inhibited genes involved in tumor progression in MCF-7 and LCC2 cells. In vivo, THZ1 boosted the effect of tamoxifen on tumor weight and tumor volume, reduced Ki67 and CD31 expression, and increased apoptotic cell death. Our findings identify CDK7 as a possible therapeutic target for breast cancer whether it is sensitive or resistant to tamoxifen therapy.

scholarly journals miR-338-3p Is Regulated by Estrogens through GPER in Breast Cancer Cells and Cancer-Associated Fibroblasts (CAFs)

Cells ◽  
2018 ◽  
Vol 7 (11) ◽  
pp. 203 ◽  
Author(s):  
Adele Vivacqua ◽  
Anna Sebastiani ◽  
Anna Miglietta ◽  
Damiano Rigiracciolo ◽  
Francesca Cirillo ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Cells ◽  
Cancer Progression ◽  
Breast Cancer Cells ◽  
Molecular Mechanisms ◽  
Cell Types ◽  
Cancer Associated Fibroblasts ◽  
Breast Cancer Patients ◽  
Expression Of Genes ◽  
Taqman Array

Estrogens acting through the classic estrogen receptors (ERs) and the G protein estrogen receptor (GPER) regulate the expression of diverse miRNAs, small sequences of non-coding RNA involved in several pathophysiological conditions, including breast cancer. In order to provide novel insights on miRNAs regulation by estrogens in breast tumor, we evaluated the expression of 754 miRNAs by TaqMan Array in ER-negative and GPER-positive SkBr3 breast cancer cells and cancer-associated fibroblasts (CAFs) upon 17β-estradiol (E2) treatment. Various miRNAs were regulated by E2 in a peculiar manner in SkBr3 cancer cells and CAFs, while miR-338-3p displayed a similar regulation in both cell types. By METABRIC database analysis we ascertained that miR-338-3p positively correlates with overall survival in breast cancer patients, according to previous studies showing that miR-338-3p may suppress the growth and invasion of different cancer cells. Well-fitting with these data, a miR-338-3p mimic sequence decreased and a miR-338-3p inhibitor sequence rescued the expression of genes and the proliferative effects induced by E2 through GPER in SkBr3 cancer cells and CAFs. Altogether, our results provide novel evidence on the molecular mechanisms by which E2 may regulate miR-338-3p toward breast cancer progression.

Targeting PSG1 to enhance chemotherapeutic efficacy: new application for anti-coagulant the dicumarol

2016 ◽  
Vol 130 (24) ◽  
pp. 2267-2276 ◽  
Author(s):  
Dong-xu He ◽  
Feng Gu ◽  
Jian Wu ◽  
Xiao-Ting Gu ◽  
Chun-Xiao Lu ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Patients ◽  
Transforming Growth Factor ◽  
Expression Profiles ◽  
Gene Expression Profiles ◽  
Transforming Growth Factor Β ◽  
Clinical Samples ◽  
Breast Cancer Patients

Chemotherapeutic response is critical for the successful treatment and good prognosis in cancer patients. In this study, we analysed the gene expression profiles of preoperative samples from oestrogen receptor (ER)-negative breast cancer patients with different responses to taxane-anthracycline-based (TA-based) chemotherapy, and identified a group of genes that was predictive. Pregnancy specific beta-1-glycoprotein 1 (PSG1) played a central role within signalling pathways of these genes. Inhibiting PSG1 can effectively reduce chemoresistance via a transforming growth factor-β (TGF-β)-related pathway in ER-negative breast cancer cells. Drug screening then identified dicumarol (DCM) to target the PSG1 and inhibit chemoresistance to TA-based chemotherapy in vitro, in vivo, and in clinical samples. Taken together, this study highlights PSG1 as an important mediator of chemoresistance, whose effect could be diminished by DCM.

scholarly journals Interaction between GRP78 and IGFBP-3 Affects Tumourigenesis and Prognosis in Breast Cancer Patients

Cancers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3821
Author(s):  
Hanna A. Zielinska ◽  
Carl S. Daly ◽  
Ahmad Alghamdi ◽  
Amit Bahl ◽  
Muhammed Sohail ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Patients ◽  
Cancer Progression ◽  
Survival Rates ◽  
Breast Cancer Cell Lines ◽  
Breast Cancer Patients ◽  
Kaplan Meier ◽  
Induced Apoptosis ◽  
Igfbp 3

Insulin-like growth factor binding protein 3 (IGFBP-3) plays a key role in breast cancer progression and was recently shown to bind to the chaperone protein glucose-regulated protein 78 (GRP78); however, the clinical significance of this association remains poorly investigated. Here we report a direct correlation between the expression of GRP78 and IGFBP-3 in breast cancer cell lines and tumour sections. Kaplan–Meier survival plots revealed that patients with low GRP78 expression that are positive for IGFBP-3 had poorer survival rates than those with low IGFBP-3 levels, and we observed a similar trend in the publicly available METABRIC gene expression database. With breast cancer cells, in vitro IGFBP-3 enhanced induced apoptosis, however when GRP78 expression was silenced the actions of IGFBP-3 were switched from increasing to inhibiting ceramide (C2)-induced cell death and promoted cell invasion. Using immunofluorescence and cell surface biotinylation, we showed that knock-down of GRP78 negated the entry of IGFBP-3 into the cells. Together, our clinical and experimental results suggest that loss of GRP78 reduces IGFBP-3 entry into cells switching its actions to promote tumorigenesis and predicts a poor prognosis in breast cancer patients.

scholarly journals miR-370-3p as a Novel Biomarker Promotes Breast Cancer Progression by Targeting FBLN5

2021 ◽  
Vol 2021 ◽  
pp. 1-18
Author(s):  
Jiahui Mao ◽  
Lingxia Wang ◽  
Junying Wu ◽  
Yichun Wang ◽  
Huiyan Wen ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cell Proliferation ◽  
Cancer Patients ◽  
Signaling Pathway ◽  
Cancer Progression ◽  
Breast Cancer Progression ◽  
Breast Cancer Patients ◽  
Potential Biomarker

miRNAs play a crucial part in multiple biological processes of cell proliferation, migration, apoptosis, and chemoresistance. In cancer, miRNAs can be divided into oncogenes or tumor suppressors on the basis of their functions in the carcinogenic process. The purpose of this study was to explore the roles and clinical diagnostic value of miR-370-3p in breast cancer. Our results demonstrated that miR-370-3p significantly promoted proliferation, metastasis, and stemness of breast cancer in vitro and in vivo. In particular, clinical data revealed that high expression of serum miR-370-3p and exosomal miR-370-3p from breast cancer patients was remarkably correlated with lymphatic metastasis and tumor node metastasis (TNM) stages. Mechanistically, miR-370-3p inhibited FBLN5 expression and activated the NF-κB signaling pathway to promote breast cancer cell proliferation, migration, and stemness. FBLN5 expression was significantly decreased in breast cancer cells and tumor tissues of breast cancer patients. Our research identified that miR-370-3p promoted breast cancer progression by inhibiting FBLN5 expression and activating the NF-κB signaling pathway. Serum exosomal miR-370-3p would provide a potential biomarker for the diagnosis of breast cancer.

scholarly journals Identification of Staphylococcal Nuclease Domain-containing 1 (SND1) as a Metadherin-interacting Protein with Metastasis-promoting Functions

2011 ◽  
Vol 286 (22) ◽  
pp. 19982-19992 ◽  
Author(s):  
Mario Andres Blanco ◽  
Maša Alečković ◽  
Yuling Hua ◽  
Tuo Li ◽  
Yong Wei ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Progression ◽  
Large Scale ◽  
Staphylococcal Nuclease ◽  
Experimental Models ◽  
Breast Cancer Patients ◽  
Interacting Protein ◽  
Primary Tumors ◽  
Nuclease Domain ◽  
Expression Of Genes

Metastasis is the deadliest and most poorly understood feature of malignant diseases. Recent work has shown that Metadherin (MTDH) is overexpressed in over 40% of breast cancer patients and promotes metastasis and chemoresistance in experimental models of breast cancer progression. Here we applied mass spectrometry-based screen to identify staphylococcal nuclease domain-containing 1 (SND1) as a candidate MTDH-interacting protein. After confirming the interaction between SND1 and MTDH, we tested the role of SND1 in breast cancer and found that it strongly promotes lung metastasis. SND1 was further shown to promote resistance to apoptosis and to regulate the expression of genes associated with metastasis and chemoresistance. Analyses of breast cancer clinical microarray data indicated that high expression of SND1 in primary tumors is strongly associated with reduced metastasis-free survival in multiple large scale data sets. Thus, we have uncovered SND1 as a novel MTDH-interacting protein and shown that it is a functionally and clinically significant mediator of metastasis.

scholarly journals Advanced co-culture 3D breast cancer model for investigation of fibrosis induced by external stimuli: optimization study

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Ilya Yakavets ◽  
Aurelie Francois ◽  
Alice Benoit ◽  
Jean-Louis Merlin ◽  
Lina Bezdetnaya ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Tumor Microenvironment ◽  
Cancer Cells ◽  
Culture Media ◽  
Luminal Breast Cancer ◽  
Radiation Toxicity ◽  
Cellular Interactions ◽  
Breast Cancer Patients ◽  
Vitro Model

AbstractRadiation-induced fibrosis (RIF) is the main late radiation toxicity in breast cancer patients. Most of the current 3D in vitro breast cancer models are composed by cancer cells only and are unable to reproduce the complex cellular homeostasis within the tumor microenvironment to study RIF mechanisms. In order to account complex cellular interactions within the tumor microenvironment, an advanced 3D spheroid model, consisting of the luminal breast cancer MCF-7 cells and MRC-5 fibroblasts, was developed. The spheroids were generated using the liquid overlay technique in culture media into 96-well plates previously coated with 1% agarose (m/v, in water). In total, 21 experimental setups were tested during the optimization of the model. The generated spheroids were characterized using fluorescence imaging, immunohistology and immunohistochemistry. The expression of ECM components was confirmed in co-culture spheroids. Using α-SMA staining, we confirmed the differentiation of healthy fibroblasts into myofibroblasts upon the co-culturing with cancer cells. The induction of fibrosis was studied in spheroids treated 24 h with 10 ng/mL TGF-β and/or 2 Gy irradiation. Overall, the developed advanced 3D stroma-rich in vitro model of breast cancer provides a possibility to study fibrosis mechanisms taking into account 3D arrangement of the complex tumor microenvironment.

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