scholarly journals SAT-139 STAT5A Regulation by Serine Phosphorylation in Breast Cancer

2020 ◽  
Vol 4 (Supplement_1) ◽  
Author(s):  
Alicia E Woock ◽  
Jacqueline M Grible ◽  
Patricija Zot ◽  
J Chuck Harrell ◽  
Idowu Michael ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Transcription Factor ◽  
Transcriptional Activity ◽  
Target Genes ◽  
Nuclear Translocation ◽  
Cancer Cell Line ◽  
Canonical Pathway ◽  
Serine Phosphorylation ◽  
Cancer Pathogenesis

Abstract The neuroendocrine hormone prolactin (PRL) and its cognate receptor (PRLr) have been implicated in the pathogenesis of breast cancer. PRL signaling relies on activating kinases such as the tyrosine kinase Jak2 and serine/threonine kinases ERK1/2, Nek3, PI3K, and AKT. In the canonical pathway of PRL signaling, Jak2 phosphorylates the transcription factor Stat5a at tyrosine residue 694 (pY694-Stat5a), preceding Stat5a nuclear translocation and transcriptional activity. However, Stat5a exists with functional duality as a transcription factor, having both pro-differentiative and pro-proliferative target genes. Other Stat family members (Stats 1, 3, and 6) have been shown to have transcriptional activity in the un-phosphorylated (upY) state, distinct from that of pY-Stat activity. This distinction (upY vs. pY) may underlie the duality of Stat5a, coupled with additional regulatory non-canonical post-translational modifications. Within this notion, Stat5a contains two serine residues, S726 and S780, whose phosphorylation are necessary for hematopoietic transformation. However, their functions in PRL-mediated breast cancer pathogenesis have not been examined. We hypothesize that Stat5a serine phosphorylation regulates Stat5a nuclear activity in a non-canonical fashion, contributing to its role in mammary oncogenesis. As shown in a tissue microarray (TMA), human breast cancer tissues express both pS726- and pS780-Stat5a. Nuclear Allred score for pS726-Stat5a increases two-fold with increasing tumor grade, with no difference in staining associated with estrogen or progesterone receptor (ER, PR) status, nor other clinical characteristics. Likewise, patient derived xenograft (PDX) tumors of various molecular subtypes express pS726- and pS780-Stat5a. Phosphorylation of S726-Stat5a is PRL-responsive in vitro. Pharmacologic inhibition of ERK1/2 prevents this phosphorylation, uncovering a novel pathway in which ERK1/2 mediates Stat5a activity in response to PRL in breast cancer. To examine the functional significance of Stat5a serine phosphorylation in vitro, we have performed Stat5a knockdown (KD) in the breast cancer cell line MCF7. Following Stat5a KD, cells were rescued with phospho-site specific Stat5a mutant constructs. Characteristics of breast cancer examined in these mutation-carrying cells, including anchorage-independent growth and proliferation, show distinct phenotypes compared to controls. PRL-induced expression of the CISH gene is significantly decreased up to 65% in the mutation-carrying cells compared to wild type Stat5a. Mechanistic studies will examine the ability of these Stat5a mutants to undergo nuclear translocation and interact with other transcription factors. Collectively, these studies have the potential to provide novel insights into the role of the non-canonical pathway of Stat5a activation in breast cancer pathogenesis.

scholarly journals Serine residues 726 and 780 have nonredundant roles regulating STAT5a activity in luminal breast cancer

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Alicia E. Woock ◽  
Jacqueline M. Grible ◽  
Amy L. Olex ◽  
J. Chuck Harrell ◽  
Patricija Zot ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Breast Cancer Cells ◽  
Target Genes ◽  
Serine Phosphorylation ◽  
Luminal Breast Cancer ◽  
Tyrosine Residue ◽  
Wild Type ◽  
Cancer Pathogenesis ◽  
Functional Pathways

AbstractIn breast cancer, prolactin-induced activation of the transcription factor STAT5a results from the phosphorylation of STAT5a tyrosine residue 694. However, its role in mammary oncogenesis remains an unsettled debate as STAT5a exhibits functional dichotomy with both pro-differentiative and pro-proliferative target genes. Phosphorylation of STAT5a serine residues, S726 and S780, may regulate STAT5a in such a way to underlie this duality. Given hematopoiesis studies showing phospho-serine STAT5a as necessary for transformation, we hypothesized that serine phosphorylation regulates STAT5a activity to contribute to its role in mammary oncogenesis, specifically in luminal breast cancer. Here, phosphorylation of S726-, S780-, and Y694-STAT5a in response to prolactin in MCF7 luminal breast cancer cells was investigated with STAT5a knockdown and rescue with Y694F-, S726A-, or S780A-STAT5a, where the phospho-sites were mutated. RNA-sequencing and subsequent Ingenuity Pathway Analysis predicted that loss of each phospho-site differentially affected both prolactin-induced gene expression as well as functional pathways of breast cancer (e.g. cell survival, proliferation, and colony formation). In vitro studies of anchorage-independent growth and proliferation confirmed distinct phenotypes: whereas S780A-STAT5a decreased clonogenicity, S726A-STAT5a decreased proliferation in response to prolactin compared to wild type STAT5a. Collectively, these studies provide novel insights into STAT5a activation in breast cancer pathogenesis.

scholarly journals The ERBB4/HER4 receptor tyrosine kinase regulates gene expression by functioning as a STAT5A nuclear chaperone

2004 ◽  
Vol 167 (3) ◽  
pp. 469-478 ◽  
Author(s):  
Christopher C. Williams ◽  
June G. Allison ◽  
Gregory A. Vidal ◽  
Matthew E. Burow ◽  
Barbara S. Beckman ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Gene Expression ◽  
Transcription Factor ◽  
Nuclear Translocation ◽  
Cancer Cell Line ◽  
Nuclear Accumulation ◽  
Intracellular Domain ◽  
Receptor Signal ◽  
Transcription Factor Target ◽  
Lactating Breast

In the lactating breast, ERBB4 localizes to the nuclei of secretory epithelium while regulating activities of the signal transducer and activator of transcription (STAT) 5A transcription factor essential for milk-gene expression. We have identified an intrinsic ERBB4 NLS (residues 676–684) within the ERBB4 intracellular domain (4ICD) that is essential for nuclear accumulation of 4ICD. To determine the functional significance of 4ICD nuclear translocation in a physiologically relevant system, we have demonstrated that cotransfection of ERBB4 and STAT5A in a human breast cancer cell line stimulates β-casein promoter activity. Significantly, nuclear localization of STAT5A and subsequent stimulation of the β-casein promoter requires nuclear translocation of 4ICD. Moreover, 4ICD and STAT5A colocalize within nuclei of heregulin β1 (HRG)-stimulated cells and both proteins bind to the endogenous β-casein promoter in T47D breast cancer cells. Together, our results establish a novel molecular mechanism of transmembrane receptor signal transduction involving nuclear cotranslocation of the receptor intracellular domain and associated transcription factor. Subsequent binding of the two proteins at transcription factor target promoters results in activation of gene expression.

scholarly journals E2F1 Drives Breast Cancer Metastasis by Regulating the Target Gene FGF13 and Altering Cell Migration

2019 ◽  
Author(s):  
Daniel P. Hollern ◽  
Matthew R. Swiatnicki ◽  
Jonathan P. Rennhack ◽  
Sean A. Misek ◽  
Brooke C. Matson ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cell Migration ◽  
Pulmonary Metastasis ◽  
Target Gene ◽  
Cancer Metastasis ◽  
Target Genes ◽  
Cancer Cell Line ◽  
Breast Cancer Metastasis ◽  
E2f Transcription Factors

ABSTRACTIn prior work we demonstrated that loss of E2F transcription factors inhibits metastasis. Here we address the mechanisms for this phenotype and identify the E2F regulated genes that coordinate tumor cell metastasis. Transcriptomic profiling of E2F1 knockout tumors identified a role for E2F1 as a master regulator of a suite of pro-metastatic genes, but also uncovered E2F1 target genes with an unknown role in pulmonary metastasis. High expression of one of these genes, Fgf13, is associated with early human breast cancer metastasis in a clinical dataset. Together these data led to the hypothesis that Fgf13 is critical for breast cancer metastasis, and that upregulation of Fgf13 may partially explain how E2F1 promotes breast cancer metastasis. To test this hypothesis we ablated Fgf13 via CRISPR. Deletion of Fgf13 in a MMTV-PyMT breast cancer cell line reduces the frequency of pulmonary metastasis. In addition, loss of Fgf13 reduced in vitro cell migration, suggesting that Fgf13 may be critical for tumor cells to invade out of and escape the primary tumor. The significance of this work is twofold: we have both uncovered genomic features by which E2F1 regulates metastasis and we have identified new pro-metastatic functions for the E2F1 target gene Fgf13.

A Novel Triazole Derivative Drug Presenting In Vitro and In Vivo Anticancer Properties

2018 ◽  
Vol 18 (17) ◽  
pp. 1483-1493
Author(s):  
Ricardo Imbroisi Filho ◽  
Daniel T.G. Gonzaga ◽  
Thainá M. Demaria ◽  
João G.B. Leandro ◽  
Dora C.S. Costa ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Cells ◽  
Cell Line ◽  
Cancer Cell ◽  
Cancer Cell Line ◽  
Hepatic Function ◽  
Anticancer Properties ◽  
Mcf 7

Background: Cancer is a major cause of death worldwide, despite many different drugs available to treat the disease. This high mortality rate is largely due to the complexity of the disease, which results from several genetic and epigenetic changes. Therefore, researchers are constantly searching for novel drugs that can target different and multiple aspects of cancer. Experimental: After a screening, we selected one novel molecule, out of ninety-four triazole derivatives, that strongly affects the viability and proliferation of the human breast cancer cell line MCF-7, with minimal effects on non-cancer cells. The drug, named DAN94, induced a dose-dependent decrease in MCF-7 cells viability, with an IC50 of 3.2 ± 0.2 µM. Additionally, DAN94 interfered with mitochondria metabolism promoting reactive oxygen species production, triggering apoptosis and arresting the cancer cells on G1/G0 phase of cell cycle, inhibiting cell proliferation. These effects are not observed when the drug was tested in the non-cancer cell line MCF10A. Using a mouse model with xenograft tumor implants, the drug preventing tumor growth presented no toxicity for the animal and without altering biochemical markers of hepatic function. Results and Conclusion: The novel drug DAN94 is selective for cancer cells, targeting the mitochondrial metabolism, which culminates in the cancer cell death. In the end, DAN94 has been shown to be a promising drug for controlling breast cancer with minimal undesirable effects.

scholarly journals The inhibitory potency of isoxazole-curcumin analogue for the management of breast cancer: A comparative in vitro and molecular modeling investigation

2021 ◽  
Author(s):  
Fiona C. Rodrigues ◽  
N. V. Anil Kumar ◽  
Gangadhar Hari ◽  
K. S. R. Pai ◽  
Goutam Thakur
Keyword(s):  
Breast Cancer ◽  
Herbal Remedy ◽  
Cancer Cell Line ◽  
Heterocyclic Ring ◽  
Regulatory Role ◽  
Multiple Traits ◽  
One Pot ◽  
Anticancer Efficacy ◽  
Improved Stability

AbstractCurcumin, a potent phytochemical derived from the spice element turmeric, has been identified as a herbal remedy decades ago and has displayed promise in the field of medicinal chemistry. However, multiple traits associated with curcumin, such as poor bioavailability and instability, limit its effectiveness to be accepted as a lead drug-like entity. Different reactive sites in its chemical structure have been identified to incorporate modifications as attempts to improving its efficacy. The diketo group present in the center of the structural scaffold has been touted as the group responsible for the instability of curcumin, and substituting it with a heterocyclic ring contributes to improved stability. In this study, four heterocyclic curcumin analogues, representing some broad groups of heterocyclic curcuminoids (isoxazole-, pyrazole-, N-phenyl pyrazole- and N-amido-pyrazole-based), have been synthesized by a simple one-pot synthesis and have been characterized by FTIR, 1H-NMR, 13C-NMR, DSC and LC–MS. To predict its potential anticancer efficacy, the compounds have been analyzed by computational studies via molecular docking for their regulatory role against three key proteins, namely GSK-3β—of which abnormal regulation and expression is associated with cancer; Bcl-2—an apoptosis regulator; and PR which is a key nuclear receptor involved in breast cancer development. One of the compounds, isoxazole-curcumin, has consistently indicated a better docking score than the other tested compounds as well as curcumin. Apart from docking, the compounds have also been profiled for their ADME properties as well as free energy binding calculations. Further, the in vitro cytotoxic evaluation of the analogues was carried out by SRB assay in breast cancer cell line (MCF7), out of which isoxazole-curcumin (IC50–3.97 µM) has displayed a sevenfold superior activity than curcumin (IC50–21.89 µM). In the collation of results, it can be suggested that isoxazole-curcumin behaves as a potential lead owing to its ability to be involved in a regulatory role with multiple significant cancer proteins and hence deserves further investigations in the development of small molecule-based anti-breast cancer agents. Graphic abstract

scholarly journals Isolation and Establishment of a Highly Proliferative, Cancer Stem Cell-Like, and Naturally Immortalized Triple-Negative Breast Cancer Cell Line, KAIMRC2

Cells ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1303
Author(s):  
Rizwan Ali ◽  
Hajar Al Zahrani ◽  
Tlili Barhoumi ◽  
Alshaimaa Alhallaj ◽  
Abdullah Mashhour ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Stem Cell ◽  
Cancer Stem Cell ◽  
Cell Line ◽  
Cancer Cell ◽  
Triple Negative Breast Cancer ◽  
Breast Cancer Cell Line ◽  
Triple Negative ◽  
Cancer Cell Line

In vitro studies of a disease are key to any in vivo investigation in understanding the disease and developing new therapy regimens. Immortalized cancer cell lines are the best and easiest model for studying cancer in vitro. Here, we report the establishment of a naturally immortalized highly tumorigenic and triple-negative breast cancer cell line, KAIMRC2. This cell line is derived from a Saudi Arabian female breast cancer patient with invasive ductal carcinoma. Immunocytochemistry showed a significant ratio of the KAIMRC2 cells’ expressing key breast epithelial and cancer stem cells (CSCs) markers, including CD47, CD133, CD49f, CD44, and ALDH-1A1. Gene and protein expression analysis showed overexpression of ABC transporter and AKT-PI3Kinase as well as JAK/STAT signaling pathways. In contrast, the absence of the tumor suppressor genes p53 and p73 may explain their high proliferative index. The mice model also confirmed the tumorigenic potential of the KAIMRC2 cell line, and drug tolerance studies revealed few very potent candidates. Our results confirmed an aggressive phenotype with metastatic potential and cancer stem cell-like characteristics of the KAIMR2 cell line. Furthermore, we have also presented potent small molecule inhibitors, especially Ryuvidine, that can be further developed, alone or in synergy with other potent inhibitors, to target multiple cancer-related pathways.

In vitro toxicological assessment of flumethrin’s effects on MCF-7 breast cancer cells

2021 ◽  
pp. 096032712110227
Author(s):  
S Kara-Ertekin ◽  
S Yazar ◽  
M Erkan
Keyword(s):  
Breast Cancer ◽  
Cancer Cell Line ◽  
Tail Length ◽  
Tail Moment ◽  
High Concentration ◽  
Toxicological Assessment ◽  
Estrogenic Effects ◽  
Pyrethroid Pesticides ◽  
Mcf 7

Pyrethroid pesticides are frequently used for household insect control of insects and in agriculture and livestock. Flumethrin is a pyrethroid that is used against ectoparasites in many animals. The goal of this study was to evaluate the cytotoxic, apoptotic, genotoxic, and estrogenic effects of flumethrin on the mammalian breast cancer cell line (MCF-7). Compared with control groups, a dose-dependent decrease was observed in cell viability at concentrations of 100 µM and higher. The cytotoxic and apoptotic effects detected by LDH assay and AO/EtBr staining increased significantly at a concentration of 1000 µM. The expression of BCL2, which is an anti-apoptotic gene, significantly decreased, whereas BAX, TP53, and P21 expression significantly increased. The results of a comet assay indicated that flumethrin significantly changed tail length, tail % DNA, tail moment, and Olive tail moment in concentrations above 1 and 10 µM. In addition, a 0.1 µM concentration of flumethrin affected ERα receptor mediated cell proliferation and increased transcription of estrogen-responsive pS2 (TFF1) and progesterone receptor (PGR) genes. As a result, flumethrin-induced apoptosis and cytotoxicity at a high concentration, while induced genotoxicity even at lower concentrations. Flumethrin is an endocrine disrupting insecticide with estrogenic effects at very low concentrations.

scholarly journals Integrin α3β1 Promotes Invasive and Metastatic Properties of Breast Cancer Cells through Induction of the Brn-2 Transcription Factor

Cancers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 480
Author(s):  
Rakshitha Pandulal Miskin ◽  
Janine S. A. Warren ◽  
Abibatou Ndoye ◽  
Lei Wu ◽  
John M. Lamar ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Transcription Factor ◽  
Cancer Cells ◽  
Cell Invasion ◽  
Breast Cancer Cells ◽  
Gene Promoter ◽  
Akt Inhibitor ◽  
Integrin Α3β1

In the current study, we demonstrate that integrin α3β1 promotes invasive and metastatic traits of triple-negative breast cancer (TNBC) cells through induction of the transcription factor, Brain-2 (Brn-2). We show that RNAi-mediated suppression of α3β1 in MDA-MB-231 cells caused reduced expression of Brn-2 mRNA and protein and reduced activity of the BRN2 gene promoter. In addition, RNAi-targeting of Brn-2 in MDA-MB-231 cells decreased invasion in vitro and lung colonization in vivo, and exogenous Brn-2 expression partially restored invasion to cells in which α3β1 was suppressed. α3β1 promoted phosphorylation of Akt in MDA-MB-231 cells, and treatment of these cells with a pharmacological Akt inhibitor (MK-2206) reduced both Brn-2 expression and cell invasion, indicating that α3β1-Akt signaling contributes to Brn-2 induction. Analysis of RNAseq data from patients with invasive breast carcinoma revealed that high BRN2 expression correlates with poor survival. Moreover, high BRN2 expression positively correlates with high ITGA3 expression in basal-like breast cancer, which is consistent with our experimental findings that α3β1 induces Brn-2 in TNBC cells. Together, our study demonstrates a pro-invasive/pro-metastatic role for Brn-2 in breast cancer cells and identifies a role for integrin α3β1 in regulating Brn-2 expression, thereby revealing a novel mechanism of integrin-dependent breast cancer cell invasion.

scholarly journals A prospective study revealing the role of an immune-related eRNA, WAKMAR2, in breast cancer

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Linbang Wang ◽  
Jingkun Liu ◽  
Jiaojiao Tai ◽  
Nian Zhou ◽  
Tianji Huang ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Target Genes ◽  
Pearson Correlation ◽  
Tumour Microenvironment ◽  
The Cancer Genome Atlas ◽  
Mcf7 Cells ◽  
Tumour Immunity ◽  
Immune Genes ◽  
Normal Tissues

AbstractEnhancer RNAs (eRNAs) are a subclass of non-coding RNAs that are generated during the transcription of enhancer regions and play an important role in tumourigenesis. In this study, we focused on the crucial eRNAs that participate in immune responses in invasive breast cancer (IBC). We first used The Cancer Genome Atlas and Human enhancer RNA Atlas to screen for tissue-specific eRNAs and their target genes. Through Pearson correlation analysis with immune genes, the eRNA WAKMAR2 was identified as a key candidate involved in IBC. Our further research suggested that WAKMAR2 is crucial in regulating the tumour microenvironment and may function by regulating immune-related genes, including IL27RA, RAC2, FABP7, IGLV1-51, IGHA1, and IGHD. Quantitative reverse transcription-polymerase chain reaction was used to detect the expression of WAKMAR2 in IBC and normal tissues, and the effect of WAKMAR2 on the regulation of downstream genes in MB-231 and MCF7 cells was studied in vitro. WAKMAR2 was found to be highly involved in tumour immunity and was downregulated in IBC tissues. Furthermore, the expression of WAKMAR2 and its target genes was observed at the pan-cancer level. This study provides evidence to suggest new potential targets for the treatment of breast cancer.

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