Project description:Analysis of reciprocal modulation of Runx2 and E2 signaling in BCA. Our objective was to investigate whether the interaction between estrogen and Runx2 signaling in breast cancer (BCa) could help refine an estrogen-responsive gene signature with improved prognostic value. MCF7/Rx2dox BCa cells conditionally expressing Runx2 upon doxycycline treatment were treated with estradiol and/or doxycycline to induce Runx2, and global gene expression was profiled to define genes regulated by estradiol, Runx2, or both.
Project description:Analysis of reciprocal modulation of Runx2 and E2 signaling in BCA. Our objective was to investigate whether the interaction between estrogen and Runx2 signaling in breast cancer (BCa) could help refine an estrogen-responsive gene signature with improved prognostic value.
Project description:Catechol-O-methyl transferase (COMT) is involved in detoxification of catechol estrogens, playing cancer-protective role in cells producing or utilizing estrogen. Moreover, COMT suppressed migration potential of breast cancer cells. To delineate COMT role in metastasis of estrogen receptor dependent BC, we investigated the effect of COMT overexpression on invasion, transcriptome, proteome and interactome of MCF7 cells, a luminal A breast cancer model, stably transduced with lentiviral vector carrying COMT gene (MCF7-COMT). This PRIDE project includes quantitative analysis results for the total proteome LC-DIA-MS/MS experiment evaluating COMT overexpression in MCF7 breast cancer cell line, and results of pulldown analysis of COMT-interacting proteins in MCF7 cells.
Project description:Endocrine therapy resistance is a clinical problem for the management of estrogen receptor (ER)-positive breast cancer. The elucidation of factors that modulate ER signaling will provide useful information for understanding the pathophysiology of ER-positive and endocrine-resistant breast cancers. In the screen of estrogen-inducible lncRNAs transcribed from ER alpha-associated active promoters/enhancers, a novel estrogen-inducible lncRNA BNAT1 (breast cancer natural antisense transcript 1), which is transcribed from the proximal promoter region of COL18A1, was identified in ER+ MCF7 cells. siRNA-mediated BNAT1 silencing significantly inhibited the in vitro and in vivo growth of tamoxifen-resistant MCF7 cells.To examine the role of long non-coding RNA BNAT1 (alias gene name COL18AS was used in this dataset) in ER+ breast cancer, MCF7 cells were treated with siRNAs targeting BNAT1 (siCOL18AS, or siBNAT1) or control siRNA (siCtrl, or siControl). The microarray study showed that BNAT1 was closely associated with estrogen signaling pathway.
Project description:Estrogen signaling plays important roles in diverse physiological and pathophysiological processes. However, the relationship between estrogen signaling and epigenetic regulation is not fully understood. Here, we explored the effect of estrogen signaling on the expression of Ten-Eleven Translocation (TET) family genes and DNA hydroxylmethylation in estrogen receptor alpha positive (ERα+) breast cancer cells. By analyzing the RNA-seq data, we identified TET2 as an estradiol (E2)-responsive gene in ERα+ MCF7 cells. RT-qPCR and Western blot analyses confirmed that both the mRNA and protein levels of TET2 gene were upregulated in MCF7 cells by E2 treatment. ChIP-seq and qPCR analyses showed that the enrichment of ERα and H3K27ac on the upstream regulatory regions of TET2 gene was increased in MCF7 cells upon E2 treatment. Moreover, E2 treatment also led to a significant increase in the global 5-hydroxymethylcytosine (5hmC) level, while knockout of TET2 abolished such E2-induced 5hmC increase. Conversely, treatment with ICI 182780, a potent and selective estrogen receptor degrader (SERD), inhibited TET2 gene expression and down-regulated the 5hmC level in MCF7 cells. Taken together, our study identified an ERα/TET2/5hmC epigenetic pathway, which may participate in the estrogen-associated physiological and pathophysiological processes.
Project description:The transcription factor RUNX1 exhibits recurrent loss-of-function mutations in estrogen receptor-positive (ER+) breast cancer (BCa). Its knockdown in vitro decreased AXIN1 expression in estrogen-dependent manner. Consistently, RUNX1 and AXIN1 mRNA levels are strongly correlated in ER+, not ER- tumors. RUNX1 occupies AXIN1â??s second intron in living cells, abutting an ERa-binding site. Potentially promoting BCa progression, decreased AXIN1 expression after RUNX1 knockdown associated with upregulation of b-catenin, and this was preventable by AXIN stabilizers. Unlike in colon cancer, however, deregulation of b-catenin in BCa cells affect neither c-Myc, nor CCND1, nor G1/S cell cycle phase transition. Instead, cyclin B1 was decreased and the G2/M checkpoint was compromised as indicated by mitotic slippage in the presence of microtubule disruptors. Thus, combined analysis of the RUNX1 transcriptome, its cistrome, and differential mRNA expression in tumors with wild type versus mutant RUNX1, altogether highlight a role for the RUNX1/AXIN1/b-catenin axis in ER+ BCa. Significance: Three recent exome sequencing studies assigned to RUNX1 a BCa suppressor role. The present study begins to uncover the underlying molecular mechanisms, offers an explanation for the specificity to ER+ tumors, and marks AXIN1 as a therapeutic target for ER+/RUNX1- BCa. Examination of RUNX1 binding in MCF7 cells
Project description:Effect of PBX1 silencing on global gene expression of MCF7 cells stimulated with estradiol. The hypothesis tested was that PBX1 is essential for estrogen signaling in ERa positive breast cancer cells.
Project description:Previous studies have identified an interaction between RUNX1 and estrogen receptor alpha and its potential role in estrogen signaling in breast cancer. To determine the transcriptomic actions of RUNX1, we knocked down its expression by using siRNAs, both in the absence and presence of estradiol (E2).
Project description:The estrogen receptor alpha (ERa) drives the growth of two-thirds of all breast cancers. Endocrine therapy impinges on estrogen-induced ERa activation to block tumor growth. However, half of ERa-positive breast cancers are tolerant or acquire endocrine therapy resistance. Here we demonstrate that breast cancer cells undergo genome-wide reprogramming of their chromatin landscape, defined by epigenomic maps and chromatin openness, as they acquire resistance to endocrine therapy. This reveals a role for the Notch pathway while excluding classical ERa signaling. In agreement, blocking Notch signaling, using gamma-secretase inhibitors, or targeting its downstream gene PBX1 abrogates growth of endocrine therapy-resistant breast cancer cells. Moreover Notch signaling through PBX1 directs a transcriptional program predictive of tumor outcome and endocrine therapy response. Comparing histone modifications (H3K4me2 and H3K36me3), chromatin openness (FAIRE) and PBX1 binding between endocrine therapy sensitive MCF7 and resistant MCF7-LTED cells.
