Invasion Of Breast Carcinoma Cells Research Articles

Hypoxia-induced miR-181a-5p up-regulation reduces epirubicin sensitivity in breast cancer cells through inhibiting EPDR1/TRPC1 to activate PI3K/AKT signaling pathway

Breast carcinoma (BC) ranks as a predominant malignancy and constitutes the second principal cause of mortality among women globally. Epirubicin stands as the drug of choice for BC therapeutics. Nevertheless, the emergence of chemoresistance has significantly curtailed its therapeutic efficacy. The resistance mechanisms to Epirubicin remain not entirely elucidated, yet they are conjectured to stem from diminished tumor vascular perfusion and resultant hypoxia consequent to Epirubicin administration. In our investigation, we meticulously scrutinized the Gene Expression Omnibus database for EPDR1, a gene implicated in hypoxia and Epirubicin resistance in BC. Subsequently, we delineated the impact of EPDR1 on cellular proliferation, motility, invasive capabilities, and interstitial-related proteins in BC cells, employing methodologies such as the CCK-8 assay, Transwell assay, and western blot analysis. Our research further unveiled that hypoxia-induced miR-181a-5p orchestrates the regulation of BC cell duplication, migration, invasion, and interstitial-related protein expression via modulation of EPDR1. In addition, we identified TRPC1, a gene associated with EPDR1 expression in BC, and substantiated that EPDR1 influences BC cellular dynamics through TRPC1-mediated modulation of the PI3K/AKT signaling cascade. Our findings underscore the pivotal role of EPDR1 in the development of BC. EPDR1 was found to be expressed at subdued levels in BC tissues, Epirubicin-resistant BC cells, and hypoxic BC cells. The overexpression of EPDR1 curtailed BC cell proliferation, motility, invasiveness, and the expression of interstitial-related proteins. At a mechanistic level, the overexpression of hypoxia-induced miR-181a-5p was observed to inhibit the EPDR1/TRPC1 axis, thereby activating the PI3K/AKT signaling pathway and diminishing the sensitivity to Epirubicin in BC cells. In summation, our study demonstrates that the augmentation of hypoxia-induced miR-181a-5p diminishes Epirubicin sensitivity in BC cells by attenuating EPDR1/TRPC1 expression, thereby invigorating the PI3K/AKT signaling pathway. This exposition offers a theoretical foundation for the application of Epirubicin in BC therapy, marking a significant contribution to the existing body of oncological literature.

Impact of brain organoid-derived sEVs on metastatic adaptation and invasion of breast carcinoma cells through a microphysiological system.

Brain metastases are common in triple-negative breast cancer (TNBC), suggesting a complex process of cancer spread. The mechanisms enabling TNBC cell adaptation and proliferation in the brain remain unclear. Small extracellular vesicles (sEVs) play a crucial role in communication between breast carcinoma cells and the brain. However, the lack of relevant models hinders understanding of sEV-mediated communication. The present study assesses the impact of brain organoid-derived sEVs (BO-sEVs) on various behaviours of the MDA-MB-231 cell line, chosen as a representative of TNBC in a 3D microfluidic model. Our results demonstrate that 150-200 nm sEVs expressing CD63, CD9, and CD81 from brain organoid media decrease MDA-MB-231 cell proliferation, enhance their wound-healing capacity, alter their morphology into more mesenchymal mode, and increase their stemness. BO-sEVs led to heightened PD-L1, CD49f, and vimentin levels of expression in MDA-MB-231 cells, suggesting an amplified immunosuppressive, stem-like, and mesenchymal phenotype. Furthermore, these sEVs also induced the expression of neural markers such as GFAP in carcinoma cells. The cytokine antibody profiling array also showed that BO-sEVs enhanced the secretion of MCP-1, IL-6, and IL-8 by MDA-MB-231 cells. Moreover, sEVs significantly enhance the migration and invasion of carcinoma cells toward brain organoids in a 3D organoid-on-a-chip system. Our findings emphasize the potential significance of metastatic site-derived sEVs as pivotal mediators in carcinoma progression and adaptation to the brain microenvironment, thereby unveiling novel therapeutic avenues.

MicroRNA-140-5p inhibits cellular proliferation, migration and invasion by downregulating AKT/STAT3/NF-κB pathway in breast carcinoma cells.

MicroRNA-140-5p (miR-140-5p) plays a pivotal role in human cancers. However, its role and molecular mechanisms in breast carcinoma are not fully explored. Using miR-140-5p transfected breast cancer cell line MDA-MB-231, several in vitro experiments were performed and described in this paper. They consist of the cell proliferation assay, wound healing assay, transwell assay, colony formation assays and qRTPCR. Expression levels of target proteins were determined using Western blotting. In addition, experiments on animal models were performed to study the possible role of miR-140-5p in tumorigenesis of breast carcinoma cells. The induction of experimental breast tumor in mice model was achieved through the incorporation of MDA-MB-231 tumor cells subcutaneously into the middle left side of the mice. The results showed that miR-140-5p up-regulation significantly suppresses proliferation, cellular invasion and migration of breast carcinoma cells. Furthermore, miR-140-5p up-regulation stops breast cancer cells at G0/G1 phase. The results of the animal model indicated that up-regulation of miR-140-5p suppresses its tumorigenic ability. Moreover, we also found that miR-140-5p up-regulation reduces the phosphorylation level of STAT3, p65, and AKT. In addition, miR-140-5p overexpression significantly decreases CDK2 expression while increasing E-cadherin expression level. These data revealed that miR-140-5p suppressed tumor progression of breast carcinoma cells through inhibition of the AKT/STAT3/NF-κB pathway. Taken the present study results together, we can conclude that miR-140-5p may act as a novel target in microRNA-targeting anticancer strategy for the treatment of breast cancer.

Extracellular Vesicle-Mediated Metastasis Suppressors NME1 and NME2 Modify Lipid Metabolism in Fibroblasts

Simple SummaryCommunication between cancer and stromal cells involves paracrine signalling mediated by extracellular vesicles (EVs). EVs transmit essential factors among cells of the tumour microenvironment. EVs derived from both cancer and stromal cells have been implicated in tumour progression. In this study, we focused on the first identified metastasis suppressor NME1, and on its close homolog NME2, and investigated their function in EVs in the interplay between cancer and stromal cells.Nowadays, extracellular vesicles (EVs) raise a great interest as they are implicated in intercellular communication between cancer and stromal cells. Our aim was to understand how vesicular NME1 and NME2 released by breast cancer cells influence the tumour microenvironment. As a model, we used human invasive breast carcinoma cells overexpressing NME1 or NME2, and first analysed in detail the presence of both isoforms in EV subtypes by capillary Western immunoassay (WES) and immunoelectron microscopy. Data obtained by both methods showed that NME1 was present in medium-sized EVs or microvesicles, whereas NME2 was abundant in both microvesicles and small-sized EVs or exosomes. Next, human skin-derived fibroblasts were treated with NME1 or NME2 containing EVs, and subsequently mRNA expression changes in fibroblasts were examined. RNAseq results showed that the expression of fatty acid and cholesterol metabolism-related genes was decreased significantly in response to NME1 or NME2 containing EV treatment. We found that FASN (fatty acid synthase) and ACSS2 (acyl-coenzyme A synthetase short-chain family member 2), related to fatty acid synthesis and oxidation, were underexpressed in NME1/2-EV-treated fibroblasts. Our data show an emerging link between NME-containing EVs and regulation of tumour metabolism.

Upregulated flotillins and sphingosine kinase 2 derail AXL vesicular traffic to promote epithelial-mesenchymal transition.

Altered endocytosis and vesicular trafficking are major players during tumorigenesis. Flotillin overexpression, a feature observed in many invasive tumors and identified as a marker of poor prognosis, induces a deregulated endocytic and trafficking pathway called upregulated flotillin-induced trafficking (UFIT). Here, we found that in non-tumoral mammary epithelial cells, induction of the UFIT pathway promotes epithelial-to-mesenchymal transition (EMT) and accelerates the endocytosis of several transmembrane receptors, including AXL, in flotillin-positive late endosomes. AXL overexpression, frequently observed in cancer cells, is linked to EMT and metastasis formation. In flotillin-overexpressing non-tumoral mammary epithelial cells and in invasive breast carcinoma cells, we found that the UFIT pathway-mediated AXL endocytosis allows its stabilization and depends on sphingosine kinase 2, a lipid kinase recruited in flotillin-rich plasma membrane domains and endosomes. Thus, the deregulation of vesicular trafficking following flotillin upregulation, and through sphingosine kinase 2, emerges as a new mechanism of AXL overexpression and EMT-inducing signaling pathway activation.

Role of miR-100-5p and CDC25A in breast carcinoma cells.

ObjectiveTo inquiry about mechanism of miR-100-5p/CDC25A axis in breast carcinoma (BC), thus offering a new direction for BC targeted treatment.MethodsqRT-PCR was employed to explore miR-100-5p and CDC25A mRNA levels. Western blot was employed for detecting protein expression of CDC25A. Targeting relationship of miR-100-5p and CDC25A was verified by dual-luciferase assay. In vitro experiments were used for assessment of cell functions.ResultsIn BC tissue and cells, miR-100-5p was significantly lowly expressed (P < 0.05) while CDC25A was highly expressed. Besides, miR-100-5p downregulated CDC25A level. miR-100-5p had a marked influence on the prognosis of patients. The forced miR-100-5p expression hindered BC cell proliferation, migration and invasion, and facilitated cell apoptosis. Upregulated miR-100-5p weakened promotion of CDC25A on BC cell growth.ConclusionTogether, these findings unveiled that CDC25A may be a key target of miR-100-5p that mediated progression of BC cells. Hence, miR-100-5p overexpression or CDC25A suppression may contribute to BC diagnosis.

Artesunate-induced Cellular Effects Are Mediated by Specific EPH Receptors and Ephrin Ligands in Breast Carcinoma Cells

The aberrant regulation of erythropoietin-producing hepatocellular carcinoma (EPH) receptors and ephrin ligands has been implicated in breast carcinoma, and artesunate has been shown to have anticancer effects. The aim of this study was to characterize the involvement of EPH receptors and ephrin ligands in mediating artesunate (ART)-induced growth suppression of normal breast cells and breast carcinoma cell lines. The normal breast epithelial cells (MCF10A), non-invasive ductal breast carcinoma cells (MCF7), and invasive triple-negative breast carcinoma cells (MDA-MB-231) were grown in the absence or the presence of different concentrations of artesunate. The cells were counted, and total RNA was isolated. The abundance of transcripts corresponding to EPH receptors and ephrin ligands was determined by quantitative polymerase chain reaction. Cell viability was significantly reduced when cells were treated with artesunate, with MDA-MB-231 cells having the highest sensitivity. Artesunate had no significant effect on transcription of EPH/ephrins in MCF10A cells, but markedly increased EPHA8, EPHA10, EPHB6 and ephrin-A2 expression in MCF7 cells, and significantly increased EPHA3 and EPHA10 expression while reducing that of EPHA7 and ephrin-A3 in MDA-MB-231 cells. The relative changes in artesunate-treated MCF7 and MDA-MB-231 cells as compared to similarly treated MCF10A cells allow us to implicate combinatorial expression and receptor interactions for EPH receptor-mediated signal transduction that converges into pathways responsible for cell growth, proliferation, and apoptosis. Specifically, the alterations in EPHA7, EPHA8, EPHA10 and EPHB6 transcripts appear to be important participants in artesunate-mediated cellular effects.

Novel triazole containing zinc(II)phthalocyanine Schiff bases: Determination of photophysical and photochemical properties for photodynamic cancer therapy

A simple and efficient synthesis of novel zinc(II) phthalocyanines bearing triazole moieties was described. The synthetic approach for preparation of the phthalocyanines 1 and 13 was achieved by Schiff base condensation reaction of phthalocyanine tetracarbaldehydes 3 and 12 with 4-amino-4H-1,2,4-triazole 5 in tetrahydrofuran in reasonable yields. The photophysical and photochemical properties of the compounds 1, 3, 12 and 13 were recorded only in DMSO. The singlet oxygen generation ability of the targeted phthalocyanine Schiff bases were investigated in an attempt to understand their potential for photodynamic therapy (PDT) activity. Moreover, in vitro PDT application was performed against the MCF-7 and MDA-MB-231 invasive breast carcinoma cell lines. Preliminary assay showed that the compounds 1 and 13 possessed the phototoxicity and cytotoxicity, with a maximum of 30% MCF-7 cells dead following light irradiation. It was also revealed that the targeted phthalocyanines possess promising characteristic as photosensitizer towards tumor cells.

Chondroitin polymerizing factor promotes breast carcinoma cell proliferation, invasion and migration and affects expression of epithelial-mesenchymal transition-related markers.

Chondroitin polymerizing factor (CHPF) plays an important role in the development of certain malignant tumors. However, the role of CHPF in breast carcinoma (BRCA) and its underlying mechanism are still not fully elucidated. Expression profiles for CHPF in BRCA tissues were retrieved from The Cancer Genome Atlas database and used for prognostic analysis. Cell viability, invasion and migration were measured invitro using MCF7 and MDA-MB-231 cell lines upon knockdown or over-expression of CHPF. Bioinformatic analysis showed that CHPF was substantially upregulated in BRCA tissues, and a quantitative reverse transcriptase-PCR was performed to confirm its upregulation in BRCA cells. High expression of CHPF was observed to be significantly associated with pathologic stage, metastasis and worse prognosis. We also observed that depletion of CHPF significantly inhibited cell proliferative, invasive and migratory abilities, whereas overexpression of CHPF exerted the opposite effects. Furthermore, analysis of the GEPIA database revealed that CHPF expression is positively correlated with the epithelial-mesenchymal transition-related markers vimentin, Snail, Slug and motion-related protein matrix metallopeptidase 2; these findings were confirmed via western blotting. Our data suggest that CHPF may contribute to BRCA progression by modulating epithelial-mesenchymal transition-related markers and matrix metallopeptidase 2 expression.

Solute carrier family 12 member 8 impacts the biological behaviors of breast carcinoma cells by activating TLR/NLR signaling pathway.

This study aimed to understand the expression of solute carrier family 12 member 8 (SLC12A8) in breast carcinoma and its biological functions, as well as its effect on the Toll-like receptor /NOD-like receptor (TLR/NLR) signaling pathway. The expression of SLC12A8 was analyzed using the public RNA sequencing dataset from TCGA database and the two datasets from Oncomine database. The former dataset was also used to evaluate the prognostic value of SLC12A8 in breast carcinoma. Real-time qPCR and western blot were applied to measure relative expression of SLC12A8. Functionally, the effect of SLC12A8 on the cells proliferation and motion was studied using cell counting kit 8 and Transwell assays respectively. Mechanistic studies were conducted using Gene Set Enrichment Analysis (GSEA) and confirmed by western blot. As a result, SLC12A8 was upregulated in breast carcinoma, and high levels of SLC12A8 led to a poorer prognosis and can be regarded as an independent prognosticator for patients with breast carcinoma. Functional experiments demonstrated that SLC12A8-knockdown suppressed while SLC12A8-overexpression elevated the viability, invasiveness and motility of breast carcinoma cells. Furthermore, GSEA indicated that high SLC12A8 was positively correlated with TLR/NLR signaling pathway. Silencing SLC12A8 significantly reduced the protein expression of TLR/NLR-related markers, whereas overexpression of SLC12A8 caused an elevation on the protein expression of these markers. All these data suggested that SLC12A8 plays a promoting effect on the cells viability, invasiveness and motility in breast carcinoma by activating TLR/NLR signaling pathway.

Human adipocyte differentiation and composition of disease-relevant lipids are regulated by miR-221-3p

MicroRNA-221-3p (miR-221-3p) is associated with both metabolic diseases and cancers. However, its role in terminal adipocyte differentiation and lipid metabolism are uncharacterized. miR-221-3p or its inhibitor was transfected into differentiating or mature human adipocytes. Triglyceride (TG) content and adipogenic gene expression were monitored, global lipidome analysis was carried out, and mechanisms underlying the effects of miR-221-3p were investigated. Finally, cross-talk between miR-221-3p expressing adipocytes and MCF-7 breast carcinoma (BC) cells was studied, and miR-221-3p expression in tumor-proximal adipose biopsies from BC patients analyzed. miR-221-3p overexpression inhibited terminal differentiation of adipocytes, as judged from reduced TG storage and gene expression of the adipogenic markers SCD1, GLUT4, FAS, DGAT1/2, AP2, ATGL and AdipoQ, whereas the miR-221-3p inhibitor increased TG storage. Knockdown of the predicted miR-221-3p target, 14-3-3γ, had similar antiadipogenic effects as miR-221-3p overexpression, indicating it as a potential mediator of mir-221-3p function. Importantly, miR-221-3p overexpression inhibited de novo lipogenesis but increased the concentrations of ceramides and sphingomyelins, while reducing diacylglycerols, concomitant with suppression of sphingomyelin phosphodiesterase, ATP citrate lyase, and acid ceramidase. miR-221-3p expression was elevated in tumor proximal adipose tissue from patients with invasive BC. Conditioned medium of miR-221-3p overexpressing adipocytes stimulated the invasion and proliferation of BC cells, while medium of the BC cells enhanced miR-221-3p expression in adipocytes. Elevated miR-221-3p impairs adipocyte lipid storage and differentiation, and modifies their ceramide, sphingomyelin, and diacylglycerol content. These alterations are relevant for metabolic diseases but may also affect cancer progression.

DNA replication and sister chromatid cohesion 1 promotes breast carcinoma progression by modulating the Wnt/β-catenin signaling and p53 protein

The objective of this study is to assess the prognostic and functional role of DSCC1 in breast carcinoma, as well as the potential mechanism. Based upon the TCGA data, the expression pattern and prognostic value of DSCC1 in breast carcinoma was evaluated. The mRNA and protein levels of molecules were determined using qRT-PCR and Western blot. In vitro functional role of DSCC1 in tumor cells was determined using cell counting kit 8, clone formation, and Transwell assays. Gene set enrichment analysis (GSEA) was conducted to determine DSCC1 related gene sets, which are further confirmed by Western blot. The results showed that DSCC1 is overexpressed in breast carcinoma tissues and its high expression was linked to shorter overall survival. Overexpression of DSCC1 facilitated the proliferation, invasion and migration of breast carcinoma cells, while knockdown of DSCC1 showed opposite outcomes. GSEA showed that high DSCC1 expression had a positive correlation with p53, and Wnt signaling-related molecules. Western blot showed that silencing DSCC1 increased the levels of p53 and p-β-catenin, whereas decreased p-GSK-3β and cyclin D1 expression. These observations illustrate that DSCC1 emerges a well value on the diagnosis and prognosis of breast carcinoma, and facilitates the progression of breast carcinoma partly by activating Wnt/b-catenin signaling and inhibiting p53.

LncRNA ADAMTS9-AS1 Restrains the Aggressive Traits of Breast Carcinoma Cells via Sponging miR-513a-5p.

PurposeLong noncoding RNAs (lncRNAs) exert important functions in the progression of cancers. Currently, we aim to investigate the potential roles of lncRNA ADAM Metallopeptidase with Thrombospondin Type 1 Motif 9 Antisense RNA 1 (ADAMTS9-AS1) in breast carcinoma.Materials and MethodsThe expressions of ADAMTS9-AS1 and miR-513a-5p in breast carcinoma tissues and cell lines were detected using qRT-PCR. Cell Counting Kit-8 (CCK-8) and transwell assays were used to assess the viability and invasive ability of breast cancer cells. The direct interaction between ADAMTS9-AS1 and miR-513a-5p was predicted using bioinformatics tools. The target of miR-513a-5p, ZFP36 Ring Finger Protein (ZFP36) was validated by luciferase assay. The expression of ZFP36 was measured using Western blot assay. Breast cancer MDA-MB-231 cells growth in vivo was evaluated using xenograft tumor assay.ResultsADAMTS9-AS1 was downregulated in breast cancer tissues as well as cell lines. Upregulation of ADAMTS9-AS1 suppressed the growth and invasiveness of breast carcinoma cells in vitro as well as inhibiting cellgrowth in vivo. Furthermore, ZFP36 was manifested as the target gene of miR-513a-5p and negatively modulated by ADAMTS9-AS1. In addition, overexpression of ADAMTS9-AS1 neutralized the promoting impact of miR-513a-5p on the aggressiveness of breast cancer cells.ConclusionIn conclusion, lncRNA ADAMTS9-AS1 inhibited the aggressive phenotypes of breast carcinoma cells via sponging miR-513a-5p and regulating ZFP36.

Abstract A16: The α-arrestin ARRDC3 functions as a metastasis suppressor by regulating GPCR activation of the Hippo pathway

Abstract G protein-coupled receptors (GPCRs) are key regulators of the Hippo pathway, a well-established mediator of tumorigenesis and cancer progression. The Hippo pathway is a promising therapeutic target, yet developing inhibitors for the core pathway components has proven difficult. As critical regulators of the Hippo pathway, GPCRs represent a potential upstream therapeutic target for cancer. However, despite the success and promise of GPCRs as therapeutic targets, there are currently no FDA-approved drugs targeting GPCRs for cancer. Protease-activated receptor-1 (PAR1) is a GPCR that has been shown to activate the Hippo pathway and also promote breast cancer progression. PAR1 is overexpressed in breast cancer patient tissue biopsies and in breast carcinoma cell lines and correlates with increased rates of metastasis and poor prognosis and increased invasion and metastatic potential, respectively. One mechanism that leads to PAR1 aberrant overexpression is defective lysosomal trafficking and degradation of the receptor, leading to persistent signaling. We recently showed that arrestin domain containing protein-3 (ARRDC3), an adaptor protein for E3 ubiquitin ligases, functions as a tumor suppressor by controlling proper PAR1 trafficking and degradation in highly aggressive, triple-negative breast carcinoma cells. The dysregulation of PAR1 trafficking due to loss of ARRDC3 expression leads to persistent signaling and promotes breast cancer invasion. However, the mechanism by which ARRDC3 specifically regulates PAR1-stimulated Hippo signaling to promote breast cancer metastasis remains unknown. Here, we show that ARRDC3 regulates GPCR activation of the Hippo pathway in basal-like breast cancer, where the transcriptional coactivators YAP and TAZ play differential roles in GPCR-mediated signaling and invasive capacity. ARRDC3 re-expression in invasive breast carcinoma cells attenuates PAR1-mediated activation of the Hippo pathway through regulation of TAZ but not YAP activation. Furthermore, siRNA knockdown of TAZ inhibits PAR1-stimulated Hippo signaling and invasion, whereas YAP siRNA knockdown has no effect. Our studies suggest a crucial role for ARRDC3 and TAZ in PAR1-Hippo pathway signaling in breast carcinoma invasion and metastasis. A better understanding of the mechanisms by which the Hippo pathway is regulated by GPCRs may lead to new potential therapeutic targets for the treatment or prevention of metastatic breast cancer. Citation Format: Aleena K.S. Arakaki, Wen-An Pan, Helen Wedegaertner, JoAnn Trejo. The α-arrestin ARRDC3 functions as a metastasis suppressor by regulating GPCR activation of the Hippo pathway [abstract]. In: Proceedings of the AACR Special Conference on the Hippo Pathway: Signaling, Cancer, and Beyond; 2019 May 8-11; San Diego, CA. Philadelphia (PA): AACR; Mol Cancer Res 2020;18(8_Suppl):Abstract nr A16.

Transmembrane protein 92 performs a tumor-promoting function in breast carcinoma by contributing to the cell growth, invasion, migration and epithelial-mesenchymal transition

ObjectiveWe try to examine the role of transmembrane protein 92 (TMEM92) in the progression of breast carcinoma (BC) and assess its prognostic value. Moreover, the effects of TMEM92 on BC cell phenotypes was explored. MethodsThe levels of TMEM92 in BC tissues were evaluated using bioinformatics analysis according to the Oncomine and The Cancer Genome Atlas databases. mRNA levels of TMEM92 in BC cells were measured by qRT-PCR. Kaplan-Meier methods together with log-rank tests were used to conduct survival analysis, and chi-square tests were employed to assess the relationship between TMEM92 levels and clinicopathological parameters. Cox regression analysis was carried out to identify the independent prognosticators. Small interference RNA targeted to TMEM92 and plasmid vectors pcDNA3.1-TMEM92 were respectively used to silence and over-express TMEM92. Protein levels of molecules in this study were tested by western blot. Cell viability, invasiveness and motility of BC cells were determined by cell counting kit 8, clone formation assay and Transwell assay, appropriately. ResultsThe data showed that TMEM92 was upregulated in BC tissues or cells in comparison with control. High expression of TMEM92 was notably correlated with stage and metastasis, and led to a poor overall survival. Moreover, cox multivariate analysis model demonstrated that TMEM92 can be seen as an independent prognostic factor. Functional experiments demonstrated that downregulation of TMEM92 showed a significantly inhibitory effect on MDA-MB-231 cell viability, invasiveness and motility, whereas overexpression of TMEM92 could promote the changes of these phenotypes. Furthermore, western blot analysis revealed that depletion of TMEM92 inactivated the epithelial-mesenchymal transition (EMT) process with raised E-cadherin protein levels, while declined N-cadherin, Vimentin and Snail levels. However, enhancement of TMEM92 showed the opposite outcomes on these EMT-related markers. ConclusionTMEM92 had an independent prognostic value for BC patients, and might act as an oncogene to facilitate tumor cells growth, invasiveness and motility by modulating the EMT relative proteins.

Tumor suppressor OTUD3 induces growth inhibition and apoptosis by directly deubiquitinating and stabilizing p53 in invasive breast carcinoma cells

BackgroundP53 pathway inactivation plays an important role in the process of breast cancer tumorigenesis. Post-translational protein modification abnormalities have been confirmed to be an important mechanism underlying inactivation of p53. Numerous deubiquitinating enzymes are aberrantly expressed in breast cancer, and a few deubiquitination enzymes can deubiquitinate and stabilize p53. Here, we report that ovarian tumor (OTU) deubiquitinase 3 (OTUD3) is a deubiquitylase of p53 in breast carcinoma (BC).MethodsCorrelations between the mRNA expression levels of OTUD3, TP53 and PTEN and the prognosis of BC were assessed with the Kaplan-Meier Plotter tool. OTUD3 protein expression in 80 pairs of specimens in our cohort was examined by immunohistochemistry and western blotting. The relationship among OTUD3, p53, and p21 proteins was analyzed. Half-life analysis and ubiquitylation assay were performed to elucidate the molecular mechanism by which OTUD3 stabilizes p53. The interaction between OTUD3 and p53 in BC cells was verified by a co-immunoprecipitation assay and GST pulldown experiments. MTS assay for proliferation detection, detection of apoptosis induced by cisplatin and colony formation assay were employed to investigate the functional effects of OTUD3 on breast cancer cells.ResultsOTUD3 downregulation is correlated with a poor prognosis in BC patients. OTUD3 expression is decreased in breast cancer tissues and not associated with the histological grade. OTUD3 also inhibits cell proliferation and clone formation and increases the sensitivity of BC cells to apoptosis induced by chemotherapy drugs. Reduced OTUD3 expression accompanied by decreased p53 abundance is correlated with human breast cancer progression. Ectopic expression of wild-type OTUD3, but not its catalytically inactive mutant, stabilizes and activates p53. Mechanistically, OTUD3 interacts directly with p53 through the amino-terminal OTU region. Finally, OTUD3 protects p53 from murine double minute 2 (Mdm2)-mediated ubiquitination and degradation, enabling the deubiquitination of p53 in BC cells.ConclusionsIn summary, we found that OTUD3 may be a potential therapeutic target for restoring p53 function in breast cancer cells and suggest that the OTUD3-p53 signaling axis may play a critical role in tumor suppression.

Regulation of GPCR activation of the Hippo pathway in metastatic breast cancer

G protein‐coupled receptors (GPCRs) regulate the Hippo signaling pathway, a developmental pathway involved in tumorigenesis and metastasis. Although GPCRs promote cancer progression and are highly druggable, there are currently no FDA‐approved drugs targeting GPCRs for cancer treatment. Protease‐activated receptor‐1 (PAR1) is a GPCR that both activates the Hippo pathway and promotes breast cancer progression. PAR1 is overexpressed in breast cancer patient tumor biopsies and in invasive breast carcinoma cell lines, and correlates with increased metastasis and poor prognosis. We found that PAR1 overexpression is due to defective lysosomal trafficking and results in persistent signaling observed in multiple triple‐negative breast carcinoma cell lines including the model invasive MDA‐MB‐231 cells. We recently showed that the α‐arrestin domain containing protein‐3 (ARRDC3), a tumor suppressor, is reduced or lost in highly aggressive triple‐negative breast carcinoma and this is responsible for aberrant PAR1 lysosomal trafficking and persistent signaling, leading to increased invasion. However, the link between ARRDC3 expression and PAR1‐stimulated Hippo pathway regulation in invasive breast cancer is not known and was examined. Here, we show that ARRDC3 regulates GPCR activation of the Hippo pathway in triple‐negative breast cancer, where the transcriptional co‐activators YAP and TAZ display distinct functions. ARRDC3 re‐expression in invasive breast carcinoma cells attenuates GPCR‐stimulated Hippo signaling and invasion that is mediated by activation of TAZ but not YAP. Furthermore, siRNA‐targeted depletion of TAZ, but not YAP inhibits GPCR‐induced Hippo signaling and invasion. An understanding of the mechanisms by which the Hippo pathway is regulated by GPCRs may lead to new potential therapeutic targets for the treatment or prevention of metastatic breast cancer.Support or Funding InformationFunding for this project was provided by the HHMI Gilliam Fellowship for Advanced Study, the UCSD Graduate Training Program in Cellular and Molecular Pharmacology through NIH General Medical Sciences, T32 GM007752 and the UCSD Tribal Membership Initiative (Aleena Arakaki) and by the National Institute of Health NIGMS R01 GM090689 and R35 GM127121 (JoAnn Trejo).

The Effects of Houttuynia cordata Thunb and Piper ribesioides Wall Extracts on Breast Carcinoma Cell Proliferation, Migration, Invasion and Apoptosis.

Houttuynia cordata Thunb. (HCT) and Piper ribesioides Wall. (PR) are common herbs that are widely distributed throughout East Asia and possess various biological properties including anti-cancer effects. However, in breast cancer, their mechanisms responsible for anti-carcinogenic effects have not been clarified yet. In this study, the inhibitory effects of HCT and PR ethanolic extracts on breast cancer cell proliferation, migration, invasion and apoptosis were examined. In MCF-7 and MDA-MB-231 cells, HCT and PR extracts at low concentrations can inhibit colony formation and induce G1 cell cycle arrest by downregulating cyclinD1 and CDK4 expression. Additionally, HCT and PR extracts also decreased the migration and invasion of both breast cancer cell lines through inhibition of MMP-2 and MMP-9 secretion. Moreover, the induction of apoptosis was observed in breast cancer cells treated with high concentrations of HCT and PR extracts. Not only stimulated caspases activity, but HCT and PR extracts also upregulated the expression of caspases and pro-apoptotic Bcl-2 family proteins in breast cancer cells. Altogether, these findings provide the rationale to further investigate the potential actions of HCT and PR extracts against breast cancer in vivo.

PODXL2 maintains cellular stemness and promotes breast cancer development through the Rac1/Akt pathway.

The cluster of differentiation 34 (CD34) family, which includes CD34, podocalyxin-like protein 1 (PODXL), and PODXL2, are type-I transmembrane sialomucins and markers of hematopoietic stem cells (HSCs) and vascular-associated tissues. CD34 family proteins are expressed by endothelial cells and hematopoietic precursors. PODXL is well known to be associated with invadopodia formation and to promote the epithelial-mesenchymal transition, tumor migration and invasion. PODXL expression was correlated with poor survival of cancer patients. However, the role of PODXL2 in cancer has been less fully explored. To reveal the novel role of PODXL2 in breast cancer, the present study evaluated PODXL2 levels in relation to clinical outcomes of cancer patients by performing a bioinformatics analysis using the Oncomine database, Kaplan-Meier plots, and the CCLE database. Empirical validation of bioinformatics predictions was conducted utilizing the short hairpin (sh)-RNA silencing method for PODXL2 in the BT474 invasive ductal breast carcinoma cell line. The bioinformatics analysis revealed that PODXL2 overexpression was correlated with poor survival of breast cancer patients, suggesting an oncogenic role of PODXL2 in breast carcinoma. In a validation experiment, knockdown of PODXL2 in BT474 cells slightly influenced cell proliferation, suppressed migration, and inhibited expressions of downstream molecules, including Ras-related C3 botulinum toxin substrate 1 (Rac1), phosphorylated (p)-Akt (S473), and p-paxillin (Y31) proteins. In addition, knockdown of PODXL2 reduced expression levels of cancer stem cell (CSC) markers, including Oct-4 and Nanog, and the breast CSC marker aldehyde dehydrogenase 1 (ALDH1). Collectively, our present study demonstrated that PODXL2 plays a crucial role in cancer development and could serve as a potential prognostic biomarker in breast cancer patients.

Stem-like Cells from Invasive Breast Carcinoma Cell Line MDA-MB-231 Express a Distinct Set of Eph Receptors and Ephrin Ligands.

Breast cancer cell lines consist of bulk tumor cells and a small proportion of stem-like cells. While the bulk cells are known to express a distinct combination of Eph receptors and ephrin ligands, the transcript profiles of stem-like cells in these cell lines have not been adequately characterized. The aim of this study was to determine Eph receptor/ephrin ligand profiles of cancer stem cells specific to a triple negative breast carcinoma cell line. The normal breast cell line MCF10A and the invasive breast carcinoma cell line MDA-MB-231 were used to isolate CD24+/CD24- cell populations. The profiles of Eph receptors and ephrin ligands were determined by real-time PCR and the relative abundance in bulk and stem cells were compared. Based on the mean ΔCT values, the descending order of abundance was as follows. Ephrin-A5 > EPHA2 > (EPHA8, EPHB2) > ephrin-B2 > (EPHA7, EPHB4, ephrin-A4) > ephrin-A3 > ephrin-A1 > (EPHB3, ephrin-B1) > EPHA4 > EPHA1 > EPHA10. EPHA6 and ephrin-A2 transcripts were not detectable in stem cells from either cell line. The expression of EPHA4, EPHA7, EPHA8, and ephrin-A5 in MDA-MB-231 stem cells was up-regulated by 12, 20, ~500, and 6.5-fold respectively. The up-regulation of transcripts for EPHA8 and its cognate ligand, ephrin-A5, in the stem cells isolated from MDA-MB-231, suggest their involvement in the invasiveness of this cell line. Based on literature reports, we propose the role of EPHA8 and ephrin-A5 in MDA-MB-231 stem cells via the PI3K-AKT-mTOR pathway.