scholarly journals Validation of Novel Transcriptional Targets that Underpin CD44-promoted breast cancer cell invasion

2021 ◽  
Author(s):  
Salma Ahmad ◽  
Hanan Nazar ◽  
Nouralhuda Alatieh ◽  
Maryam Al-Mansoob ◽  
Zainab Farooq ◽  
...  

Introduction: Breast cancer (BC) is the most common cancer worldwide, and metastasis is its worst aspect and the first cause of death. Metastasis is a multistep process, where an invasion is a recurring event. The process of BC cell invasion involves three major factors, including cell adhesion molecules (CAM), proteinases and Growth factors.CD44, a family of CAM proteins and the hyaluronic acid (HA) cell surface receptor, acts as cell differentiation, cell migration/invasion and apoptosis regulator. Rationale: We have previously established a tetracycline (Tet)-OFF-regulated expression system, both in vitro and in vivo (Hill et al, 2006). As a complementary approach, the highly metastatic MDA-MB-231 BC cells expressing high levels of endogenous CD44s (the standard form of CD44), was cultured in the presence and absence of 50 µg/ml of HA. RNA samples were isolated from both cell experimental models, and microarray analysis (12K CHIP from Affymetrix) was applied. More than 200 CD44s transcriptional target genes were identified and were sub-divided into groups of genes based on their function: cell motility, cytoskeletal organization, ability to degrade ECM, and cell survival. Hypothesis: Among these 200 identified genes, we selected seven genes (ICAP-1, KYNU, AHR, SIRT1, SRSF8, PRAD1, and SOD2) and hypothesized that based on evidence from literature, these genes are potential novel targets of CD44-downstream signaling mediating BC cell invasion. Specific Aims: Pursuant to this goal, we proposed the following objectives: 1- Structural validation of ICAP-1, KYNU, AHR, SIRT1, SRSF8, PRAD1 and SOD2 as novel transcriptional targets of CD44/HA-downstream signaling at both RNA and Protein level using reverse transcription polymerase chain reaction (RT-PCR) and Western Blot respectively. 2-Functional validation of ICAP-1, KYNU, AHR, SIRT1, SRSF8, PRAD1and SOD2 as novel transcriptional targets that underpin CD44-promoted BC cell migration using wound healing assay after the transfection with siRNA. Innovation/Consclusion: This study validated seven transcriptional targets of CD44/HA-downstream signaling promoting BC cell invasion. Ongoing experiments aim to dissect the signaling pathways that link CD44 activation by HA to the transcription of these seven genes.

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Maria De Luca ◽  
Roberta Romano ◽  
Cecilia Bucci

AbstractV-ATPase is a large multi-subunit complex that regulates acidity of intracellular compartments and of extracellular environment. V-ATPase consists of several subunits that drive specific regulatory mechanisms. The V1G1 subunit, a component of the peripheral stalk of the pump, controls localization and activation of the pump on late endosomes and lysosomes by interacting with RILP and RAB7. Deregulation of some subunits of the pump has been related to tumor invasion and metastasis formation in breast cancer. We observed a decrease of V1G1 and RAB7 in highly invasive breast cancer cells, suggesting a key role of these proteins in controlling cancer progression. Moreover, in MDA-MB-231 cells, modulation of V1G1 affected cell migration and matrix metalloproteinase activation in vitro, processes important for tumor formation and dissemination. In these cells, characterized by high expression of EGFR, we demonstrated that V1G1 modulates EGFR stability and the EGFR downstream signaling pathways that control several factors required for cell motility, among which RAC1 and cofilin. In addition, we showed a key role of V1G1 in the biogenesis of endosomes and lysosomes. Altogether, our data describe a new molecular mechanism, controlled by V1G1, required for cell motility and that promotes breast cancer tumorigenesis.


2019 ◽  
Author(s):  
Daniel P. Hollern ◽  
Matthew R. Swiatnicki ◽  
Jonathan P. Rennhack ◽  
Sean A. Misek ◽  
Brooke C. Matson ◽  
...  

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.


2021 ◽  
Author(s):  
Junping Lu ◽  
Xiaoxia Tian ◽  
Mailisu Mailisu ◽  
Morigen Morigen ◽  
Lifei Fan

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.


Cancers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 480
Author(s):  
Rakshitha Pandulal Miskin ◽  
Janine S. A. Warren ◽  
Abibatou Ndoye ◽  
Lei Wu ◽  
John M. Lamar ◽  
...  

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.


Molecules ◽  
2021 ◽  
Vol 26 (8) ◽  
pp. 2204
Author(s):  
Meng-Die Yang ◽  
Yang Sun ◽  
Wen-Jun Zhou ◽  
Xiao-Zheng Xie ◽  
Qian-Mei Zhou ◽  
...  

Triple-negative breast cancer (TNBC) is a refractory type of breast cancer that does not yet have clinically effective drugs. The aim of this study is to investigate the synergistic effects and mechanisms of resveratrol combined with cisplatin on human breast cancer MDA-MB-231 (MDA231) cell viability, migration, and invasion in vivo and in vitro. In vitro, MTS assays showed that resveratrol combined with cisplatin inhibits cell viability as a concentration-dependent manner, and produced synergistic effects (CI < 1). Transwell assay showed that the combined treatment inhibits TGF-β1-induced cell migration and invasion. Immunofluorescence assays confirmed that resveratrol upregulated E-cadherin expression and downregulated vimentin expression. Western blot assay demonstrated that resveratrol combined with cisplatin significantly reduced the expression of fibronectin, vimentin, P-AKT, P-PI3K, P-JNK, P-ERK, Sma2, and Smad3 induced by TGF-β1 (p < 0.05), and increased the expression of E-cadherin (p < 0.05), respectively. In vivo, resveratrol enhanced tumor growth inhibition and reduced body weight loss and kidney function impairment by cisplatin in MDA231 xenografts, and significantly reduced the expressions of P-AKT, P-PI3K, Smad2, Smad3, P-JNK, P-ERK, and NF-κB in tumor tissues (p < 0.05). These results indicated that resveratrol combined with cisplatin inhibits the viability of breast cancer MDA231 cells synergistically, and inhibits MDA231 cells invasion and migration through Epithelial-mesenchymal transition (EMT) approach, and resveratrol enhanced anti-tumor effect and reduced side of cisplatin in MDA231 xenografts. The mechanism may be involved in the regulations of PI3K/AKT, JNK, ERK and NF-κB expressions.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Linbang Wang ◽  
Jingkun Liu ◽  
Jiaojiao Tai ◽  
Nian Zhou ◽  
Tianji Huang ◽  
...  

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.


2021 ◽  
Author(s):  
Mariska Miranda ◽  
Jodi M. Saunus ◽  
Seçkin Akgül ◽  
Mahdi Moradi Marjaneh ◽  
Jamie R. Kutasovic ◽  
...  

AbstractBackgroundThe nucleocytoplasmic shuttling of ERK5 has gained recent attention as a regulator of its diverse roles in cancer progression but the exact mechanisms for this shuttling are still under investigation.MethodsUsing in vitro, in vivo and in silico studies, we investigated the roles of shorter ERK5 isoforms in regulating the nucleocytoplasmic shuttling of active phosphorylated-ERK5 (pERK5). Retrospective cohorts of primary and metastatic breast cancer cases were used to evaluate the association of the subcellular localization of pERK5 with clinicopathological features.ResultsExtranuclear localization of pERK5 was observed during cell migration in vitro and at the invasive fronts of metastatic tumors in vivo. The nuclear and extranuclear cell fractions contained different isoforms of pERK5, which are encoded by splice variants expressed in breast and other cancers in the TCGA data. One isoform, isoform-3, lacks the C-terminal transcriptional domain and the nuclear localization signal. The co-expression of isoform-3 and full-length ERK5 associated with high epithelial-to-mesenchymal transition (EMT) and poor patient survival. Experimentally, expressing isoform-3 with full-length ERK5 in breast cancer cells increased cell migration, drove EMT and led to tamoxifen resistance. In breast cancer patient samples, pERK5 showed variable subcellular localizations where its extranuclear localization associated with aggressive clinicopathological features, metastasis, and poor survival.ConclusionOur studies support a model of ERK5 nucleocytoplasmic shuttling driven by splice variants in an interplay between mesenchymal and epithelial states during metastasis. Using ERK5 as a biomarker and a therapeutic target should account for its splicing and context-dependent biological functions.Graphical AbstractERK5 isoform-3 expression deploys active ERK5 (pERK5) outside the nucleus to facilitate EMT and cell migration. In cells dominantly expressing isoform-1, pERK5 shuttles to the nucleus to drive cell expansion.


Oncogenesis ◽  
2020 ◽  
Vol 9 (10) ◽  
Author(s):  
Wei Wang ◽  
Urna Kansakar ◽  
Vesna Markovic ◽  
Bingcheng Wang ◽  
Khalid Sossey-Alaoui

Abstract Both TGF-β and the PI3K-AKT signaling pathways are known activators of various intracellular pathways that regulate critical cellular functions, including cancer cell survival and proliferation. The interplay between these two oncogenic pathways plays a major role in promoting the initiation, growth, and progression of tumors, including breast cancers. The molecular underpinning of the inter-relationship between these pathways is, however, not fully understood, as is the role of WAVE3 phosphorylation in the regulation of tumor growth and progression. WAVE3 has been established as a major driver of the invasion–metastasis cascade in breast cancer and other tumors of epithelial origin. WAVE3 phosphorylation downstream of PI3K was also shown to regulate cell migration. Here we show that, in addition to PI3K, WAVE3 tyrosine phosphorylation can also be achieved downstream of TGF-β and EGF and that WAVE3 tyrosine phosphorylation is required for its oncogenic activity. Our in vitro analyses found loss of WAVE3 phosphorylation to significantly inhibit cell migration, as well as tumorsphere growth and invasion. In mouse models for breast cancer, loss of WAVE3 phosphorylation inhibited tumor growth of two aggressive breast cancer cell lines of triple-negative subtype. More importantly, we found that WAVE3 phosphorylation is also required for the activation of PI3K, TGF-β, and EGF signaling and their respective downstream effectors. Therefore, our study identified a novel function for WAVE3 in the regulation of breast cancer development and progression through the modulation of a positive feedback loop between WAVE3 and PI3K-TGF-β-EGF signaling pathways.


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