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 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.

TK1 in Cancer Progression: elucidating its influence on cellular invasion and survival

2019 ◽  
Author(s):  
Eliza E. Bitter ◽  
Michelle H. Townsend ◽  
Kary Y.F. Tsai ◽  
Carolyn I. Allen ◽  
Rachel I. Erickson ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cell Survival ◽  
Cancer Cells ◽  
Cell Lines ◽  
Cancer Progression ◽  
Breast Cancer Cells ◽  
S Phase ◽  
Wild Type ◽  
Cellular Invasion ◽  
Cancer Pathogenesis

Abstract 1. Background: The salvage pathway enzyme thymidine kinase 1 (TK1) is elevated in the serum of several different cancer types and higher expression is associated with more aggressive tumor grade. As a result, it has potential as a biomarker for diagnosis and prognosis. Recent studies indicate that TK1 may be involved in cancer pathogenesis; however, its direct involvement has not been identified. We propose to evaluate the effects of TK1 on cancer progression in vitro through measuring cellular invasion and survival of breast cancer cells.2.Methods: Breast cancer cells MDA-MB-231, HCC 1806, and MCF7 were cultured according to standard techniques. We employed the use of TK1 target siRNA and a CRISPR-Cas9 TK1 knockout plasmid to compare transfected cell lines to wild type cell lines. Protein factors in survival and invasive pathways were also tested for correlations to TK1 in BRCA RNA-seq patient data (n=1095) using the TIMER program. Cellular invasion was quantified in cell index (factor of impedance) over a 24-hour period. Cell survival was measured by apoptosis under metabolic and DNA stress using flow cytometry. All results were statistically assessed using an ANOVA or t-test in GraphPad PRISM®.3.Results: Cellular invasion assays assessing wild type and TK1 knockdown/knockout (TK1-/-) cell types showed TK1-/- cell lines had increased invasion potential (p= 0.0001). Bioinformatically, we saw a strong overall negative correlation between apoptotic factors and TK1 (p ≤ 0.05). When testing TK1 effects on cell survival we saw a protective affect under DNA stress (p ≤ 0.05), but not under metabolic stress (p= 0.0001).4.Conclusion From cell cycle analysis, we observed a shift towards S phase in TK1-/- cells. This shift to S phase would promote growth and account for the increased cellular invasion and decrease in metabolic induced stress in TK1-/- cells. We propose that cancer cells still may elicit a cancer progressive phenotype based on effects of TK1, but that a system which isolates TK1 is not effective to understand the effects. Instead, identifying protein networks inclusive of TK1 will help to elucidate its effects on cancer progression.

mir-556-3p Promotes the Progression of Breast Cancer Through Targeting Disabled Gene Homolog 2 Interacting Protein (DAB2IP)

2021 ◽  
Vol 11 (12) ◽  
pp. 2472-2477
Author(s):  
Chunxiong Fan ◽  
Yanping Deng ◽  
Yaqing Liu ◽  
Xiaoying Liu ◽  
Xi Ke ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cell Proliferation ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Cell Activity ◽  
Control Group ◽  
Cancer Tissue ◽  
Breast Cancer Patients ◽  
Cancer Pathogenesis

Our study assessed miR-556-3p’s role in breast cancer cells. A total of 65 cases of breast cancer tissue samples were retrospectively analyzed to detect miR-556-3p level by PCR and analyze survival time and 30 normal breast tissues were included as a control group. Breast cancer cells were cultured followed by analysis of cell proliferation by MTT, cell invasion by transwell assay. miR-556-3p level was significantly upregulated in breast cancer patients compared to control group (P <0.05) and inversely associated with survival rate (P <0.05). In vitro experiments, cell activity and invasion were positively correlated with miR-556-3p level (P <0.05). In MCF-7 cell lines, miR-556-3p overexpression increased cell activity (P <0.05). Meanwhile, after miR-556-3p was overexpressed, the expression of DAB2IP, Erk, p-Erk in breast cancer cells was significantly reduced and increased after miR-556-3p was knocked down. In conclusion, miR-556-3p targets DAB2IP3′-UTR, promotes breast cancer cell proliferation, indicating that miR-556-3p might be involved in breast cancer pathogenesis and may be a new target for the treatment.

scholarly journals Osterix Decreases the Chemosensitivity of Breast Cancer Cells by Upregulating GALNT14

2017 ◽  
Vol 44 (3) ◽  
pp. 998-1010 ◽  
Author(s):  
Jiahui Wu ◽  
Xiang Chen ◽  
Qianyi Bao ◽  
Rui Duan ◽  
Yucui Jin ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Target Genes ◽  
Disease Free Survival ◽  
Breast Cancer Patients ◽  
Elevated Expression ◽  
Hoechst Staining

Background/Aims: Osterix (Osx), a key regulator of osteoblast differentiation and bone formation, has been recently reported to be associated with the progression of breast cancer. However, the precise roles of Osx in breast cancer remain unclear. Methods: Drug sensitivity of the cancer cells was assessed using an 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay. Target genes were obtained by high-throughput Illumina sequencing and were confirmed in vitro and in vivo. Apoptosis was analysed by Hoechst staining and western blotting. A tissue microarray including 129 samples from breast cancer patients was used for immunohistochemistry (IHC) assays. Results: Overexpression of Osx decreased the chemosensitivity of breast cancer cells, while knockdown of Osx increased the chemosensitivity of breast cancer cells. In particular, we found that the decreased chemosensitivity effect was significantly associated with elevated expression of the polypeptide N-acetylgalactosaminyltransferase 14 (GALNT14). Silencing of GALNT14 in Osx-overexpressed cells restored the decreased chemosensitivity. Conversely, overexpression of GALNT14 in Osx-knockdown cells abrogated the increased chemosensitivity in breast cancer cells. In addition, we revealed that Osx decreased GALNT14-dependent chemosensitivity by enhancing anti-apoptosis. GALNT14 expression exhibited a significant association with breast cancer stages as well as the disease-free survival (DFS) rate. Conclusion: Osx plays an important role in the chemosensitivity and inhibition of Osx expression may represent a therapeutic strategy to enhance the chemosensitivity of breast cancer.

scholarly journals Cytoplasmic ATXN7L3B Interferes with Nuclear Functions of the SAGA Deubiquitinase Module

2016 ◽  
Vol 36 (22) ◽  
pp. 2855-2866 ◽  
Author(s):  
Wenqian Li ◽  
Boyko S. Atanassov ◽  
Xianjiang Lan ◽  
Ryan D. Mohan ◽  
Selene K. Swanson ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Target Genes ◽  
Histone Acetyltransferase ◽  
Adaptor Proteins ◽  
Catalytic Subunit ◽  
Saga Complex

The SAGA complex contains two enzymatic modules, which house histone acetyltransferase (HAT) and deubiquitinase (DUB) activities. USP22 is the catalytic subunit of the DUB module, but two adaptor proteins, ATXN7L3 and ENY2, are necessary for DUB activity toward histone H2Bub1 and other substrates. ATXN7L3B shares 74% identity with the N-terminal region of ATXN7L3, but the functions of ATXN7L3B are not known. Here we report that ATXN7L3B interacts with ENY2 but not other SAGA components. Even though ATXN7L3B localizes in the cytoplasm, ATXN7L3B overexpression increases H2Bub1 levels, while overexpression of ATXN7L3 decreases H2Bub1 levels. In vitro , ATXN7L3B competes with ATXN7L3 to bind ENY2, and in vivo , knockdown of ATXN7L3B leads to concomitant loss of ENY2. Unlike the ATXN7L3 DUB complex, a USP22-ATXN7L3B-ENY2 complex cannot deubiquitinate H2Bub1 efficiently in vitro . Moreover, ATXN7L3B knockdown inhibits migration of breast cancer cells in vitro and limits expression of ER target genes. Collectively, our studies suggest that ATXN7L3B regulates H2Bub1 levels and SAGA DUB activity through competition for ENY2 binding.

scholarly journals MELK is an oncogenic kinase essential for mitotic progression in basal-like breast cancer cells

eLife ◽  
2014 ◽  
Vol 3 ◽  
Author(s):  
Yubao Wang ◽  
Young-Mi Lee ◽  
Lukas Baitsch ◽  
Alan Huang ◽  
Yi Xiang ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Progesterone Receptors ◽  
Luminal Breast Cancer ◽  
Mouse Development ◽  
Basal Like Breast Cancer ◽  
Aggressive Subtype

Despite marked advances in breast cancer therapy, basal-like breast cancer (BBC), an aggressive subtype of breast cancer usually lacking estrogen and progesterone receptors, remains difficult to treat. In this study, we report the identification of MELK as a novel oncogenic kinase from an in vivo tumorigenesis screen using a kinome-wide open reading frames (ORFs) library. Analysis of clinical data reveals a high level of MELK overexpression in BBC, a feature that is largely dependent on FoxM1, a master mitotic transcription factor that is also found to be highly overexpressed in BBC. Ablation of MELK selectively impairs proliferation of basal-like, but not luminal breast cancer cells both in vitro and in vivo. Mechanistically, depletion of MELK in BBC cells induces caspase-dependent cell death, preceded by defective mitosis. Finally, we find that Melk is not required for mouse development and physiology. Together, these data indicate that MELK is a normally non-essential kinase, but is critical for BBC and thus represents a promising selective therapeutic target for the most aggressive subtype of breast cancer.

scholarly journals Prolactin and oestrogen synergistically regulate gene expression and proliferation of breast cancer cells

2010 ◽  
Vol 17 (3) ◽  
pp. 809-822 ◽  
Author(s):  
Louise Maymann Rasmussen ◽  
Klaus Stensgaard Frederiksen ◽  
Nanni Din ◽  
Elisabeth Galsgaard ◽  
Leif Christensen ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Gene Expression ◽  
Cancer Cells ◽  
Cancer Progression ◽  
Breast Cancer Cells ◽  
Target Genes ◽  
Regulation Of Gene Expression ◽  
Pituitary Hormone

The pituitary hormone prolactin (PRL) plays an important role in mammary gland development. It was also suggested to contribute to breast cancer progression. In vivo data strongly supported a crucial role of PRL in promoting tumour growth; however, PRL demonstrated only a weak, if any, pro-proliferative effect on cancer cells in vitro. Several recent studies indicated that PRL action in vivo may be influenced by the hormonal milieu, e.g. other growth factors such as 17β-oestradiol (E2). Here, we explored the potential interplay between PRL and E2 in regulation of gene expression and cell growth. PRL alone induced either a weak or no proliferative response of T47D and BT-483 cells respectively, while it drastically enhanced cell proliferation in E2-stimulated cultures. Affymetrix microarray analysis revealed 12 genes to be regulated by E2, while 57 genes were regulated by PRL in T47D cells. Most of the PRL-regulated genes (42/57) were not previously described as PRL target genes, e.g. WT1 and IER3. One hundred and five genes were found to be regulated upon PRL/E2 co-treatment: highest up-regulation was found for EGR3, RUNX2, EGR1, MAFF, GLIPR1, IER3, SOCS3, WT1 and AREG. PRL and E2 synergised to regulate EGR3, while multiple genes were regulated additively. These data show a novel interplay between PRL and E2 to modulate gene regulation in breast cancer cells.

scholarly journals Suppressing the Migration of Human Breast Cancer Cell Line by Targeting VAMP3 with miR-199a-3p

2016 ◽  
Vol 23 (2) ◽  
pp. 29-37
Author(s):  
Nouf N. Laqtom ◽  
Khloud M. Algothmi
Keyword(s):  
Breast Cancer ◽  
Metastatic Breast Cancer ◽  
Cancer Cells ◽  
Messenger Rna ◽  
Breast Cancer Cells ◽  
Target Genes ◽  
Ectopic Expression ◽  
Metastatic Breast ◽  
Antimetastatic Effect

Deregulation of microRNAs contributes to multiple processes in cancer growth and progression. miR-199a-3p is decreased in highly metastatic breast cancer cells, MDA-MB-231, and its ectopic expression has a potent antimetastatic effect on these cells. However, the mechanism by which miR-199a-3p mediates its antimetastatic function has yet to be elucidated. Because miR-199a-3p reduces the expression levels of its target genes, it is likely to observe an inverse association between miR-199a-3p and its prometastatic target genes at the expression level. The current work determines that the Vesicleassociated membrane protein 3 (VAMP3) expression is increased in highly metastatic breast cancer cells compared to less metastatic cells, Michigan Cancer Foundation-7. The ectopic expression of miR-199a-3p strongly inhibits VAMP3 Messenger RNA and protein in vitro. Herein, it is confirmed that two sites within the 3'-untranslated sequence of VAMP3 Messenger RNA are actively targeted by miR-199a- 3p, discovering a new regulatory mechanism for VAMP3 expression. Functional studies reveal that the suppression of VAMP3 contributes to miR-199a-3p antimetastatic effect, particularly cellular migration in vitro. In conclusion, these results indicate that miR-199a-3p targeting of VAMP3 possesses a significant potential impact in preventing or curing metastatic breast cancers.

scholarly journals The antihyperlipidemic drug Potassium Piperate impairs migration and tumorgenesis of breast cancer cells via upregulation of miR-31

2021 ◽  
Author(s):  
Junping Lu ◽  
Xiaoxia Tian ◽  
Mailisu Mailisu ◽  
Morigen Morigen ◽  
Lifei Fan
Keyword(s):  
Breast Cancer ◽  
Cancer Cells ◽  
Cancer Cell ◽  
Cell Invasion ◽  
Combination Treatment ◽  
Breast Cancer Cells ◽  
Target Genes ◽  
Cancer Cell Invasion

Abstract Background Breast cancer is a leading malignant tumor which causes deaths among women, and metastasis is the primary cause for mortality in breast cancer. Due to the involvement of many regulatory molecules and signaling pathways, the occurrence and development process of metastasis needs to be further studied. MicroRNAs (miRNAs) are ubiquitously expressed small non-coding RNAs that have been shown to play an important role in the diagnosis and treatment of many diseases, as well as constituting an attractive candidate to control metastasis. In this study, we tried to uncover the mechanism of GBK in impairing breast cancer cell invasion and metastasis.Methods We treated cancer cells with GBK or not, found its target miRNA by analyzed miRNA transcriptional changes and the miRNA target genes by performed with the QT-PCR and Western Blot. The proliferation of breast cancer cells in vitro and in vivo under combination treatment with GBK and DDP was measured by CCK-8 kit and the nude mice tumor formation experiment.Results We found tumor suppressor miR-31 was a main target of GBK. GBK treatment affected the epigenetic modification at CpG sites by downregulating DNA methyltransferases, thus the methylation levels at CpG of lncRNA LOC554202 decreased significantly, and in turn upregulating of both miR-31 and its host gene LOC554202 in breast cancer cells. We also observed significant inhibition of miR-31 target genes under GBK stimulation, including RhoA, WAVE3 and SATB2, which all closely related to cancer cell invasion, migration and proliferation. Furthermore, we revealed that combination treatment with GBK and DDP had synergistic and dose reduction potential in inhibiting the proliferation of breast cancer cells in vitro and in vivo, especially in TNBC.Conclusion This study further analyzes the target and underlying mechanism of GBK in inhibiting breast cancer migration and invasion, and provides theoretical support for the development of GBK as an auxiliary drug for clinical treatment.

scholarly journals Myoglobin Protects Breast Cancer Cells Due to Its ROS and NO Scavenging Properties

2021 ◽  
Vol 12 ◽  
Author(s):  
Theresa Quinting ◽  
Anna Katharina Heymann ◽  
Anne Bicker ◽  
Theresa Nauth ◽  
Andre Bernardini ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cell Survival ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Target Genes ◽  
Reactive Oxygen ◽  
Luminal Breast Cancer ◽  
Proliferating Cells ◽  
Regulatory Pathways ◽  
Glut 1

Myoglobin (MB) is an oxygen-binding protein usually found in cardiac myocytes and skeletal muscle fibers. It may function as a temporary storage and transport protein for O2 but could also have scavenging capacity for reactive oxygen and nitrogen species. In addition, MB has recently been identified as a hallmark in luminal breast cancer and was shown to be robustly induced under hypoxia. Cellular responses to hypoxia are regulated by the transcription factor hypoxia-inducible factor (HIF). For exploring the function of MB in breast cancer, we employed the human cell line MDA-MB-468. Cells were grown in monolayer or as 3D multicellular spheroids, which mimic the in vivo avascular tumor architecture and physiology with a heterogeneous cell population of proliferating cells in the rim and non-cycling or necrotic cells in the core region. This central necrosis was increased after MB knockdown, indicating a role for MB in hypoxic tumor regions. In addition, MB knockdown caused higher levels of HIF-1α protein after treatment with NO, which also plays an important role in cancer cell survival. MB knockdown also led to higher reactive oxygen species (ROS) levels in the cells after treatment with H2O2. To further explore the role of MB in cell survival, we performed RNA-Seq after MB knockdown and NO treatment. 1029 differentially expressed genes (DEGs), including 45 potential HIF-1 target genes, were annotated in regulatory pathways that modulate cellular function and maintenance, cell death and survival, and carbohydrate metabolism. Of these target genes, TMEFF1, TREX2, GLUT-1, MKNK-1, and RAB8B were significantly altered. Consistently, a decreased expression of GLUT-1, MKNK-1, and RAB8B after MB knockdown was confirmed by qPCR. All three genes of interest are often up regulated in cancer and correlate with a poor clinical outcome. Thus, our data indicate that myoglobin might influence the survival of breast cancer cells, possibly due to its ROS and NO scavenging properties and could be a valuable target for cancer therapy.

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