Invasion Of Breast Cancer Cells Research Articles

Cell Migration Chip (3DCM-chip): a New Tool Toward the Modelling of 3D Cellular Complex Systems.

3D hydrogel-based cell cultures provide models for studying cell behavior and can efficiently replicate the physiologic environment. Hydrogels can be tailored to mimic mechanical and biochemical properties of specific tissues and allow to produce gel-in-gel models. In this system, microspheres encapsulating cells are embedded in an outer hydrogel matrix, where cells are able to migrate. To enhance the efficiency of such studies, we design a lab-on-a-chip named 3D Cell Migration-chip (3DCM-chip) that offers substantial advantages over traditional methods. 3DCM-chip facilitates the analysis of biochemical and physical stimuli effects on cell migration/invasion in different cell types, including stem, normal and tumor cells. 3DCM-chip provides a smart platform for developing more complex cell co-cultures systems. Herein we investigate the impact of human fibroblasts on MDA-MB 231 breast cancer cells invasiveness. Moreover, how the presence of different cellular lines, including mesenchymal stem cells (hMSCs), normal human dermal fibroblasts (NHDFs), and human umbilical vein endothelial cells (HUVECs), affects the invasive behavior of cancer cells is investigated using 3DCM-chip and producing predictive tumoroid models with a more complex network of interactions between cells and microenvironment. 3DCM-chip moves us closer to creating in vitro systems that can potentially replicate key aspects of the physiological tumor microenvironment. This article is protected by copyright. All rights reserved.

Regulation of cellular and molecular markers of epithelial-mesenchymal transition by Brazilin in breast cancer cells.

Breast cancer is the most common invasive neoplasm and the leading cause of cancer death in women worldwide. The main cause of mortality in cancer patients is invasion and metastasis, where the epithelial-mesenchymal transition (EMT) is a crucial player in these processes. Pharmacological therapy has plants as its primary source, including isoflavonoids. Brazilin is an isoflavonoid isolated from Haematoxilum brasiletto that has shown antiproliferative activity in several cancer cell lines. In this study, we evaluated the effect of Brazilin on canonical markers of EMT such as E-cadherin, vimentin, Twist, and matrix metalloproteases (MMPs). By Western blot, we evaluated E-cadherin, vimentin, and Twist expression and the subcellular localization by immunofluorescence. Using gelatin zymography, we determined the levels of secretion of MMPs. We used Transwell chambers coated with matrigel to determine the in vitro invasion of breast cancer cells treated with Brazilin. Interestingly, our results show that Brazilin increases 50% in E-cadherin expression and decreases 50% in vimentin and Twist expression, MMPs, and cell invasion in triple-negative breast cancer (TNBC) MDA-MB-231 and to a lesser extend in MCF7 ER+ breast cancer cells. Together, these findings position Brazilin as a new molecule with great potential for use as complementary or alternative treatment in breast cancer therapy in the future.

Mutation of SIVA, a candidate metastasis gene identified from clonally related bilateral breast cancers, promotes breast cancer cell spread in vitro and in vivo.

Metastasis is the most dreaded outcome after a breast cancer diagnosis, and little is known regarding what triggers or promotes breast cancer to spread distally, or how to prevent or eradicate metastasis effectively. Bilateral breast cancers are an uncommon form of breast cancers. In our study, a percentage of bilateral breast cancers were clonally related based on copy number variation profiling. Whole exome sequencing and comparative sequence analysis revealed that a limited number of somatic mutations were acquired in this "breast-to-breast" metastasis that might promote breast cancer distant spread. One somatic mutation acquired was SIVA-D160N that displayed pro-metastatic phenotypes in vivo and in vitro. Over-expression of SIVA-D160N promoted migration and invasion of human MB-MDA-231 breast cancer cells in vitro, consistent with a dominant negative interfering function. When introduced via tail vein injection, 231 cells over-expressing SIVA-D160N displayed enhanced distant spread on IVIS imaging. Over-expression of SIVA-D160N promoted invasion and anchorage independent growth of mouse 4T1 breast cancer cells in vitro. When introduced orthotopically via mammary fat pad injection in syngeneic Balb/c mice, over-expression of SIVA-D160N in 4T1 cells increased orthotopically implanted mammary gland tumor growth as well as liver metastasis. Clonally related bilateral breast cancers represented a novel system to investigate metastasis and revealed a role of SIVA-D160N in breast cancer metastasis. Further characterization and understanding of SIVA function, and that of its interacting proteins, may elucidate mechanisms of breast cancer metastasis, providing clinically useful biomarkers and therapeutic targets.

Abstract PO3-24-07: The role of Hepatitis A Virus Cellular Receptor 1 (HAVCR1) in breast cancer and the impact on penetration of blood brain barrier

Abstract Background: Hepatitis A Virus Cellular Receptor 1 (HAVCR1) is associated with the biological behaviour of several cancers, and has been shown to regulate junctional complexes. However, its role in breast cancer remains unexplored. This study aimed to investigate the effects of HAVCR1 on human breast cancer. Methods: We explored the UALCAN web portal, which is linked to the TCGA database, to determine the expression of HAVCR1 in breast cancer and the Kaplan-Meier plotter to evaluate the correlation with the survival of the patients. HAVCR1 siRNA was used to knock down the HAVCR1 expression in MCF-7 and MDA-MB-231 cell lines. In vitro cell growth, wounding healing, and electric cell impedance sensing (ECIS for assessing cellular proliferation, migration and adhesion) assays were used. Transepithelial resistance (TEER) and paracellular permeability (PCP) were assessed to determine changes in the barrier function of human breast cancer cells. The expression of HAVCR1 and prospective interactive binding molecules of HAVCR1 protein was assessed using quantitative polymerase chain reaction (qPCR). Cellular response to docetaxel was evaluated and shown (IC50). The invasiveness of breast cancer cells through the human cerebral microvessel endothelial cells (hCMEC/D3) cell layers was measured using an in vitro transwell cell invasion assay. Results: HAVCR1 gene expression levels were significantly lower (P< 0.001) in breast cancer tissue compared with normal tissues. Patients with high expression of HAVCR1 had a significantly better relapse-free survival than low expression (P< 0.001). There was no significant difference in overall survival (OS) between the HAVCR1 high and the low expression groups (P=0.22). However, in subgroup analysis, high HAVCR1 expression was associated with better OS in luminal A (P=0.04). Knockdown (KD) HAVCR1 in breast cancer cells influence cell function by enhanced adhesion, proliferation, and migration compared to wild type (WT) cell lines. It was noted that loss of HAVCR1 rendered both MCF-7 and MDA-MB-231 cells resistant to docetaxel (IC50 for WT and HAVCR1 KD respectively being 0.86nM vs 1.75nM for MCF-7 and 1.35nM vs 15.48nM for MDA-MB-231). HAVCR1 KD increase adhesion to hCMEC/D3 cells (53.14±8.23 vs ±99.37±8.97 for MCF-7, P< 0.001; 109.5±97.56 vs 147.1±96.63 for MDA-MB-231, P=0.228, WT and HAVCR1 KD). In the cerebral endothelial cell invasion assay, we found that HAVCR1 KD resulted in a significantly increased invasion of the breast cancer cells through the endothelium (19.27±8.74 vs 33.58±16.81 for MDA-MB-231, P=0.0114, WT and HAVCR1 KD). For the barrier function, the knockdown led to a decrease in TEER and an increase in PCP when compared with WT cells in both cell lines. HAVCR1 KD cells showed decreased barrier function, together with reduced expression of Claudin-1/8/10, occludin, MarvelD3, Tricellulin and ZO1. Conclusions: HAVCR1 is a potential biomarker for breast cancer prognosis. HAVCR1 influences the integrity of barrier function by influence the gene expression of tight junction in breast cancer, and influence the penetration to blood brain barrier. Together, it suggests that HAVCR1 may be a potential therapeutic target in breast cancer. Citation Format: Xiaoshan Cao, Binbin Cong, Wen Jiang, Tracey Martin. The role of Hepatitis A Virus Cellular Receptor 1 (HAVCR1) in breast cancer and the impact on penetration of blood brain barrier [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO3-24-07.

NREP, transcriptionally upregulated by HIF-1α, aggravates breast cancer cell growth and metastasis by promoting glycolysis

Breast cancer (BC) poses a great threat to women’s health. Neuronal regeneration related protein (NREP) is a multifunctional protein that is involved in embryonic development, regeneration, and human disease. However, the biological function of NREP in tumors is rarely reported and its role in BC remains unknown. Bioinformatics analysis showed that NREP is highly expressed and closely correlated with poor survival in BC patients. Under hypoxic conditions, NREP was upregulated in BC cells, and this promotion was reversed by hypoxia-inducible factor HIF-1α suppression. Luciferase reporter system and chromatin immunoprecipitation assays confirmed that HIF-1α directly binds to the promoter of NREP to increase the transcriptional activity of NREP. NREP suppression inhibited cell proliferation, arrested the cell cycle at the G1/S phase, and promoted apoptosis and caspase-3 activity in BC cells. Suppression of NREP decreased the tube formation ability of HUVECs. In addition, NREP downregulation showed an inhibition effect on cell migration, invasion, and EMT of BC cells. In NREP overexpressed cells, all these changes were reversed. In vivo, animal experiments also confirmed that NREP promotes BC tumor growth and metastasis. In addition, NREP promoted cellular glycolysis and enhanced the levels of glucose consumption, ATP, lactate production, and glucose transporters expression in NREP-overexpressed BC cells. In summary, our results demonstrated that NREP could be transcriptional activated by HIF-1α, which may aggravate BC tumor growth and metastasis by promoting cellular glycolysis. This result suggested that NREP may play an essential part in BC progression.

Abstract PO1-13-12: Mechanistic Analysis and Potential Therapeutic Implications in Breast Cancer with Fibrotic Focus

Abstract A fibrotic focus (FF) is a scar-like region that forms in the center of carcinoma due to excessive tumor stroma formation. In our earlier studies, we found FF as an independent poor prognostic factor for breast cancers. However, the underlying mechanisms of how the presence of FF contributed to a poor prognosis are still unknown. To improve our understanding of FF in breast cancer, we have investigated genes associated with FF and their impacts on breast cancer prognosis. Analysis of data from The Cancer Genome Atlas Program (TCGA) indicated that Bone Morphogenetic Protein 8A (BMP8A) was significantly upregulated in breast cancers with FF. To further validate this finding, immunohistochemistry (IHC) on BMP8A was performed on a local cohort of breast cancers (N= 900). Of these samples, 147 (16.3%) were found to be BMP8A positive, and there was a significant association between the presence of FF and high expression of BMP8A (p-value=0.026). We also found that high expression of BMP8A was positively correlated with apocrine phenotype, necrosis, increased Ki67 expression, and triple-negative breast cancer subtype; and most of these are poor prognostic factors for breast cancer. Kaplan-Meier survival estimate analysis revealed that high expression of BMP8A was significantly associated with poor overall survival (p-value=0.035). Gene ontology (GO) analysis showed that "Extracellular matrix organization" was the prominent biological process associated with BMP8A. KEGG pathway analysis suggested that BMP8A was significantly related to "Protein digestion and absorption", "ECM-receptor interaction", and "Focal adhesion" pathways, further validating its correlation with stromal FF. In cellular studies using MCF7 and MDA-MB-231 cell lines, overexpression of BMP8A was found to enhance breast cancer cell proliferation, invasion, and migration. Similar tumor-promoting phenotypes were exhibited when stimulating the cell lines with recombinant human BMP8A. In conclusion, our findings suggested that BMP8A was associated with FF in breast cancer, contributing at least partly to the aggressive features of these cancers. Our findings also provided new insights into the precision treatment and diagnosis of breast cancer. Further exploration of BMP8A as a therapeutic target and prognostic factor may contribute to improved management of breast cancer patients. Citation Format: Canbin Fang, Julia Y. S. Tsang, Gary M.K. Tse. Mechanistic Analysis and Potential Therapeutic Implications in Breast Cancer with Fibrotic Focus [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO1-13-12.

Abstract PO4-24-03: Adiponectin modulates cell polarity according to ERα expression in breast cancer cells

Abstract INTRODUCTION: Tumor microenvironment (TME) is a complex and heterogeneous network, consisting of stromal and immune cells, embedded with cytokines, growth factors, soluble receptors, and exosomes. Mutual and dynamic crosstalk among cancer, stromal and immune cells predispose cancer cells to metastasis. Particularly, the main component of breast TME is represented by adipocytes, which secretory activity is compromised in obesity. Indeed, hypertrophic, and hyperplastic adipocytes undergo to a modified cytokines secretory pattern, characterized by a reduced secretion of Adiponectin, now recognized as a crucial factor in the pathogenesis of breast cancer. LKB1 is one the most important effector of Adiponectin transduction pathways, and recently it has been demonstrated its role as ERα coactivator in promoting breast cancer cell growth. Moreover, LKB1 is a key regulator in controlling cell polarity along with E-cadherin and Cdc42. Cell polarity has been considered essential for mammary epithelial integrity, and disruption of individual polarity proteins is sufficient to induce tumor progression. The aim of the present study was to investigate the effects of adiponectin on the regulation and alteration of cell polarity, essential for breast cancer cell growth and invasiveness. METHODS: Immunofluorescence analyses were done to detect protein localization in breast cancer cells. Protein expression was performed by immunoblotting in the presence or absence of ERa and LKB1 siRNA. LKB1/Cdc42 and LKB1/E-cadherin interaction was detected by Proximity ligation and immunoprecipitation assay respectively. Wound healing assay was carried out to evaluate GM130 orientation. Growth and metastatic potential of breast cancer cells were assessed in vivo by orthotopic model and metastatic study respectively. RESULTS: In Adiponectin-treated MCF-7 cells LKB1 is mostly present in the nucleus, recruited as ERa-coactivator, while in BT20 cells LKB1 is localized with E-cadherin in the cytosolic compartment, suggesting its role in polarity. Our results showed that in MCF-7 cells Adiponectin increases Cdc42 level depending on LKB1 expression. Moreover, Cdc42 and LKB1 interact and colocalized in the nucleus of Adiponectin-treated MCF-7 cells. On the contrary, LKB1 and Cdc42 are located with E-cadherin in the cytosol of BT20 cells, addressing their cytosolic cooperation in maintaining cell polarity, as confirmed by an increased Cdc42 activity. Immunofluorescence analyses demonstrated a lack of Golgi realignment toward the front of the leading edge in MCF-7 cells treated with Adiponectin, not observed in BT20 cells. All this suggest a loss of cell polarity organization that predispose to cancer growth and progression, as confirmed by an increased tumor volume mass and a major number of lung metastatic events upon tail vein injection of adiponectin-treated ERα-positive cells with respect to untreated cells. CONCLUSION: In ERα-positive breast cancer cells Adiponectin modulates the expression of the main proteins involved in cell polarity, leading to increased growth, progression, and distant metastasis. Citation Format: Giuseppina Daniela Naimo, Martina Forestiero, Alessandro Paolì, Luca Gelsomino, Rocco Malivindi, Adele Elisabetta Leonetti, Francesca Giordano, Maria Luisa Panno, Loredana Mauro, Sebastiano Andò. Adiponectin modulates cell polarity according to ERα expression in breast cancer cells [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO4-24-03.

Abstract PO3-06-12: Targeting Fatty Acid Synthase in Brain Metastatic Triple-negative Breast Cancer

Abstract Introduction: Treating triple-negative breast cancer (TNBC) is challenging due to the lack of clearly defined and targetable biomarkers, and treatment options become increasingly limited with TNBC brain metastases (BM). Since the brain microenvironment has relatively low lipid availability, breast cancer cells that colonize the brain increase their reliance on the endogenous biosynthesis of fatty acids. This reveals a potential metabolic vulnerability that can be targeted, and fatty acid synthase (FASN) inhibition has been shown to decrease breast cancer cell invasion in preclinical models. Methods: In our study, we utilized the TNBC cell line MDA-MB-231-Luc/GFP, its brain-seeking subclone, MDA-MB-231-BR-GFP, and two novel cell lines generated from patient-derived organoids obtained from serial collection of brain-metastatic TNBC resections from the same patient, denoted PDO-BC25 and PDO-BC25-2. Cell lines were screened with FASN inhibitors as single agents vs. combined with SN-38 (topoisomerase I inhibitor) and synergy was assessed by the Chou-Talalay method. To characterize signaling changes with FASN inhibition and identify any off-target signaling, we used a Nanostring metabolic pathways nCounter panel to perform differential expression analysis on cells treated with the FASN inhibitor, TVB-2640, vs. vehicle control across the four cell lines. This panel detects the expression of 768 metabolism-related genes. We used 4 biological replicates per sample and the Benjamini-Hochberg statistical method to control for the false discovery rate after performing a t-test to calculate P-values. In addition, we performed spheroid outgrowth assays to identify any phenotypic impacts of FASN inhibition on spheroid outgrowth. Results: Combinatory drug screening between FASN inhibitors and SN-38 revealed synergy in MDA-MB-231-BR-GFP, PDO-BC25, and PDO-BC25-2, but not in the parental MDA-MB-231-Luc/GFP. The Nanostring nCounter metabolic pathways panel identified direct target engagement where FASN, SCD, and the transcription factor SREBP1 were significantly upregulated in the cells treated with TVB-2640 compared to vehicle control (P-adjusted < 0.05). Other upregulated genes were related to the pentose phosphate pathway, nucleotide salvage and synthesis, reactive oxygen species response, amino acid synthesis and transport, and autophagy. Genes that were down-regulated are involved in cell cycle progression, deoxynucleotide synthesis, DNA damage repair, fatty acid oxidation, and cytokine and chemokine signaling. Moreover, despite no decrease in cell viability, TVB-2640 alone was able to slow the outgrowth and invasion of Matrigel-embedded spheroids in a spheroid outgrowth assay. Conclusions: In our study, we have shown that the combination of SN-38 and FASN inhibitors is synergistic in the TNBC brain-seeking cell lines, and that FASN inhibition alone causes on-target transcriptome-level changes and a decrease in spheroid invasion. Next, we plan on testing the brain-metastatic potential of these cell lines in the presence and absence of a FASN inhibitor using an organ-on-chip microfluidic device developed by our lab that mimics the blood-brain barrier, to identify if this strategy has a potential role in prevention of brain metastases. Further studies to refine the molecular basis of the mechanism of action of the combination are underway. Citation Format: Habib Serhan, Liwei Bao, Xu Cheng, Matthew Soellner, Sofia Merajver, Aki Morikawa, Nathan Merrill. Targeting Fatty Acid Synthase in Brain Metastatic Triple-negative Breast Cancer [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO3-06-12.

Oleic acid inhibits the migration and invasion of breast cancer cells with stemness characteristics through oxidative stress-mediated attenuation of the FAK/AKT/NF-κB pathway

Oleic acid, found in a variety of food sources, is beneficial to health. However, studies on its anticancer effects on cancer stem cells resistant to conventional treatments and on the mechanisms underlying such effects are scarce. Here, we evaluated the anticancer effects of oleic acid against breast cancer cells with stemness characteristics. Oleic acid inhibited the proliferation of breast cancer stem-like cells more significantly than that of their respective parental cells, and reduced the expression of stem cell markers and migration and invasion propensity. It also repressed the phosphorylation of FAK, AKT, and NF-κB, proteins involved in cell migration and invasion. Oleic acid-induced increase in reactive oxygen species levels mediated the inhibition of the FAK/AKT/NF-κB signaling axis. Our study demonstrates that oleic acid-induced oxidative stress plays an important role in inhibiting the metastatic behavior of breast cancer cells with stemness characteristics and is relevant for management of treatment-resistant breast cancer.

Anticancer Effects of Mitoquinone via Cell Cycle Arrest and Apoptosis in Canine Mammary Gland Tumor Cells.

Treating female canine mammary gland tumors is crucial owing to their propensity for rapid progression and metastasis, significantly impacting the overall health and well-being of dogs. Mitoquinone (MitoQ), an antioxidant, has shown promise in inhibiting the migration, invasion, and clonogenicity of human breast cancer cells. Thus, we investigated MitoQ's potential anticancer properties against canine mammary gland tumor cells, CMT-U27 and CF41.Mg. MitoQ markedly suppressed the proliferation and migration of both CMT-U27 and CF41.Mg cells and induced apoptotic cell death in a dose-dependent manner. Furthermore, treatment with MitoQ led to increased levels of pro-apoptotic proteins, including cleaved-caspase3, BAX, and phospho-p53. Cell cycle analysis revealed that MitoQ hindered cell progression in the G1 and S phases in CMT-U27 and CF41.Mg cells. These findings were supported using western blot analysis, demonstrating elevated levels of cleaved caspase-3, a hallmark of apoptosis, and decreased expression of cyclin-dependent kinase (CDK) 2 and cyclin D4, pivotal regulators of the cell cycle. In conclusion, MitoQ exhibits in vitro antitumor effects by inducing apoptosis and arresting the cell cycle in canine mammary gland tumors, suggesting its potential as a preventive or therapeutic agent against canine mammary cancer.

LncRNA DDX11-AS1 promotes cell growth, migration and invasion through regulating epithelial-mesenchymal transition in breast cancer.

This study aimed to investigate the expression of long non-coding ribonucleic acid (lncRNA) DDX11 antisense RNA 1 (DDX11-AS1) in breast cancer (BC) tissues and cells and investigate its biological function and potential molecular mechanism through in vitro experiments. Tissue specimens were obtained from 44 BC patients. TRIzol method was used to extract RNAs from the tissues. The relative expression of DDX11-AS1 in BC tissues and the expression of DDX11-AS1 in BC cells were detected via quantitative reverse transcription-polymerase chain reaction (qRT-PCR). The effect of DDX11-AS1 on the proliferation ability of BC cells was detected via cell counting kit-8 (CCK-8) assay. Flow cytometry was adopted to study the effect of DDX11-AS1 on the distribution of BC cell cycle. Transwell assays were performed to analyze the effects of DDX11-AS1 on the migration and invasion abilities of BC cells. Finally, after interfering with the expression of DDX11-AS1 in BC cells, changes in the expressions of molecular markers for epithelial-mesenchymal transition (EMT) were detected via Western blotting. According to the results of qRT-PCR, the expression of DDX11-AS1 was up-regulated in 38 out of 44 cases of BC tissues compared with that in the para-carcinoma tissues, and the expression of DDX11-AS1 in BC cells was up-regulated as well. After interference with the expression of DDX11-AS1 in BC cells, it was found via CCK-8 assay that the proliferation ability of BC cells was restrained, flow cytometry results showed that the BC cell cycle was arrested at G1/G0 phase, and the results of transwell assays revealed that the cell invasion and migration abilities were suppressed in experimental group compared with those in control group. According to the results of Western blotting, after interfering with the expression of DDX11-AS1 in BC cells, there were changes in the expressions of molecular markers for EMT. In BC, the expression of lncRNA DDX11-AS1 is up-regulated, which promotes the proliferation, migration and invasion of BC cells by regulating EMT.

Biological functions of PCAT-1/ SOX4 in cell proliferation and invasion of breast cancer.

Breast cancer (BC) is one of the most common fatal cancers. Recent studies have identified the vital role of long noncoding RNA (lncRNAs) in the development and progression of BC. In this research, lncRNA PCAT-1 was studied to identify how it functioned in the metastasis of BC. PCAT-1 expression of tissues was detected by real-time quantitative polymerase chain reaction (RT-qPCR) in 50 BC patients. Cell proliferation, wound healing assay and transwell assay were used to observe the biological behavior changes of BC cells through knockdown or overexpression of PCAT-1. In addition, RT-qPCR and Western blot assay were performed to discover the potential target protein of PCAT-1 in BC. PCAT-1 expression level in BC samples was higher than that of adjacent ones. Besides, cell proliferation, migrated ability and cell invaded ability of BC cells were inhibited after PCAT-1 was silenced. Cell proliferation, migration and invasion of BC cells were promoted after PCAT-1 was overexpressed. In addition, SOX4 was downregulated after silence of PCAT-1 in BC cells, while SOX4 was upregulated after overexpression of PCAT-1 in BC cells. Furthermore, SOX4 was upregulated in BC tissues and was positively associated with PCAT-1. Our study uncovers a new oncogene in BC and suggests that PCAT-1 could enhance BC cell proliferation, migration and invasion via targeting SOX4, which provided a novel therapeutic target for BC patients.

LncRNA DLG5-AS1 facilitates breast cancer cell proliferation and invasion by promoting EZH2-mediated transcriptional silencing of SFRP1

Rapid proliferation and metastasis of breast cancer contributed to poor clinical prognosis. Accumulating evidence revealed that the dysregulation of long noncoding RNAs (lncRNAs) was associated with breast cancer progression. However, the role of lncRNA DLG5-AS1 in breast cancer has not been established. Here, we investigated the mechanisms of DLG5-AS1 in the development of breast cancer. We found that the expression of DLG5-AS1 was significantly upregulated in breast cancer tissues and cell lines. DLG5-AS1 interference markedly restrained AU565 cell proliferation, invasion, the expression of apoptosis related (caspase3 and caspase8) and Wnt/β-catenin pathway related proteins (wnt5a, β-Catenin and c-Myc), as well as promoted cell apoptosis, whereas DLG5-AS1 overexpression showed an opposite effects. In addition, DLG5-AS1 could directly bind with miR-519 b-3p. We also found that enhancer of zeste homolog 2 (EZH2) is a direct target of miR-519 b-3p, and DLG5-AS1 upregulated EZH2 expression by inhibiting the expression of miR-519 b-3p. EZH2 restrained secreted frizzled related protein 1 (SFRP1) expression through inducing H3 histone methylation in its promoter. MiR-519 b-3p overexpression or SFRP1 knockdown memorably reversed the effects of DLG5-AS1 overexpression on cell functions and Wnt/β-Catenin pathway related protein expression. Finally, in vivo experiments demonstrated that silencing of DLG5-AS1 inhibited xenograft tumor development in mice. Taken together, these findings demonstrated that DLG5-AS1 facilitated cell proliferation and invasion by promoting EZH2-mediated transcriptional silencing of SFRP1 in breast cancer.

Upregulation of FGF9 and NOVA1 in cancer-associated fibroblasts promotes cell proliferation, invasion and migration of triple negative breast cancer.

Cancer-associated fibroblasts (CAFs) play a pivotal role in cancer progression. This study aimed to explore the roles of CAFs-derived Fibroblast growth factor 9 (FGF9) and Neuro-oncological ventral antigen 1 (NOVA1) in triple negative breast cancer (TNBC) progression. MDA-MB-231 and BT-549 cells were cocultured with CAF conditioned-medium (CAF-CM) or normal fibroblasts conditioned-medium (NF-CM). MTT, EdU, colony formation, wound healing, transwell migration, and invasion assays were employed to determine cell proliferation, migration and invasion, respectively. Western blot and RT-qPCR were carried out to examine the protein and mRNA expression of FGF9 and NOVA1. Xenograft tumor experiments were conducted to evaluate the effects of CAFs, FGF9, and NOVA1 on tumor growth in vivo. Our results showed that CAFs significantly promoted the proliferation, invasion, and migration of TNBC cells. FGF9 and NOVA1 were significantly upregulated in TNBC CAFs, tissues and cells. CAF-CM also could increase the expression of FGF9 and NOVA1 in TNBC cells. Knockdown of FGF9 or NOVA1 could hamper cell proliferation, invasion, migration, and EMT of TNBC cells. Moreover, CAFs with FGF9/NOVA1 knockdown also could inhibit TNBC progression. Besides, CAFs significantly accelerated tumor growth in vivo, which was blocked by FGF9/NOVA1 knockdown in nude mice. In conclusion, our results indicated the tumor-promoting role of CAFs in TNBC progression. FGF9 and NOVA1 upregulation in CAFs induced cell proliferation, migration and invasion in vitro, and facilitated tumor growth in vivo in TNBCdevelopment.

GATA4 regulates the transcription of MMP9 to suppress the invasion and migration of breast cancer cells via HDAC1-mediated p65 deacetylation

GATA-binding protein 4 (GATA4) is recognized for its significant roles in embryogenesis and various cancers. Through bioinformatics and clinical data, it appears that GATA4 plays a role in breast cancer development. Yet, the specific roles and mechanisms of GATA4 in breast cancer progression remain elusive. In this study, we identify GATA4 as a tumor suppressor in the invasion and migration of breast cancer. Functionally, GATA4 significantly reduces the transcription of MMP9. On a mechanistic level, GATA4 diminishes MMP9 transcription by interacting with p65 at the NF-κB binding site on the MMP9 promoter. Additionally, GATA4 promotes the recruitment of HDAC1, amplifying the bond between p65 and HDAC1. This leads to decreased acetylation of p65, thus inhibiting p65’s transcriptional activity on the MMP9 promoter. Moreover, GATA4 hampers the metastasis of breast cancer in vivo mouse model. In summary, our research unveils a novel mechanism wherein GATA4 curtails breast cancer cell metastasis by downregulating MMP9 expression, suggesting a potential therapeutic avenue for breast cancer metastasis.

Exosomal miRNA-92a derived from cancer-associated fibroblasts promote invasion and metastasis in breast cancer by regulating G3BP2

Cancer-associated Fibroblasts (CAFs) exert a tumor-promoting effect in various cancers, including breast cancer. CAFs secrete exosomes containing miRNA and proteins, influencing the tumor microenvironment. In this study, we identified CAF-derived exosomes that transport functional miR-92a from CAFs to tumor cells, thereby intensifying the aggressiveness of breast cancer. CAFs downregulate the expression of G3BP2 in breast cancer cells, and a significant elevation in miR-92a levels in CAF-derived exosomes was observed. Both in vitro and in vivo experiments demonstrate that miR-92a enhances breast cancer cell migration and invasion by directly targeting G3BP2, functioning as a tumor-promoting miRNA. We validated that the RNA-binding proteins SNRPA facilitate the transfer of CAF-derived exosomal miR-92a to breast cancer cells. The reduction of G3BP2 protein by CAF-derived exosomes releases TWIST1 into the nucleus, promoting epithelial-mesenchymal transition (EMT) and further exacerbating breast cancer progression. Moreover, CAF-derived exosomal miR-92a induces tumor invasion and metastasis in mice. Overall, our study reveals that CAF-derived exosomal miR-92a serves as a promoter in the migration and invasion of breast cancer cells by reducing G3BP2 and may represent a potential novel tumor marker for breast cancer.

[Retracted] Upregulation of microRNA‑181b inhibits CCL18‑induced breast cancer cell metastasis and invasion via the NF‑κB signaling pathway.

[This retracts the article DOI: 10.3892/ol.2016.5230.].

A phenotypic screening approach to target p60AmotL2-expressing invasive cancer cells

BackgroundTumor cells have the ability to invade and form small clusters that protrude into adjacent tissues, a phenomenon that is frequently observed at the periphery of a tumor as it expands into healthy tissues. The presence of these clusters is linked to poor prognosis and has proven challenging to treat using conventional therapies. We previously reported that p60AmotL2 expression is localized to invasive colon and breast cancer cells. In vitro, p60AmotL2 promotes epithelial cell invasion by negatively impacting E-cadherin/AmotL2-related mechanotransduction.MethodsUsing epithelial cells transfected with inducible p60AmotL2, we employed a phenotypic drug screening approach to find compounds that specifically target invasive cells. The phenotypic screen was performed by treating cells for 72 h with a library of compounds with known antitumor activities in a dose-dependent manner. After assessing cell viability using CellTiter-Glo, drug sensitivity scores for each compound were calculated. Candidate hit compounds with a higher drug sensitivity score for p60AmotL2-expressing cells were then validated on lung and colon cell models, both in 2D and in 3D, and on colon cancer patient-derived organoids. Nascent RNA sequencing was performed after BET inhibition to analyse BET-dependent pathways in p60AmotL2-expressing cells.ResultsWe identified 60 compounds that selectively targeted p60AmotL2-expressing cells. Intriguingly, these compounds were classified into two major categories: Epidermal Growth Factor Receptor (EGFR) inhibitors and Bromodomain and Extra-Terminal motif (BET) inhibitors. The latter consistently demonstrated antitumor activity in human cancer cell models, as well as in organoids derived from colon cancer patients. BET inhibition led to a shift towards the upregulation of pro-apoptotic pathways specifically in p60AmotL2-expressing cells.ConclusionsBET inhibitors specifically target p60AmotL2-expressing invasive cancer cells, likely by exploiting differences in chromatin accessibility, leading to cell death. Additionally, our findings support the use of this phenotypic strategy to discover novel compounds that can exploit vulnerabilities and specifically target invasive cancer cells.

M1 macrophages polarized by crude polysaccharides isolated from Auricularia polytricha exhibit anti-tumor effect on human breast cancer cells

Breast cancer has been reported to correlate with the infiltration of tumor-associated macrophages (TAMs) or M2-like macrophages in tumor microenvironment (TME) that could promote breast cancer progression. In contrast, M1-like macrophages displayed anti-tumor activity toward cancer. This study was focused on Auricularia polytricha (AP), a cloud ear mushroom, which has been reported for anti-tumor activity and immunomodulation. AP extracts were screened on differentiated THP-1 macrophages (M0). Results demonstrated that water extract (APW) and crude polysaccharides (APW-CP) could upregulate M1-related genes and cytokines production (IL-6, IL-1 β and TNF-α) significantly. Moreover, APW and APW-CP showed a high expression of CD86 (M1 marker) compared to M0. The NF-κB signaling pathway is crucial for pro-inflammatory gene regulation. The APW and APW-CP treatment showed the induction of the NF-κB pathway in a dose-dependent manner, which related to the β-glucan content in the extracts. Furthermore, APW-CP polarized macrophages were investigated for anti-tumor activity on human breast cancer cells (MCF-7 and MDA-MB-231). Results showed that APW-CP could inhibit the invasion of breast cancer cells and induce apoptosis. Therefore, M1 macrophages polarized by APW-CP showed anti-tumor activity against the breast cancer cells and β-glucan may be the potential M1-phenotype inducer.

Tubulin alpha-1b chain was identified as a prognosis and immune biomarker in pan-cancer combing with experimental validation in breast cancer

The α-tubulin subtype, Tubulin α-1b chain (TUBA1B), has been shown to influence immune cell infiltration, cancer growth, and survival across various malignancies. However, a comprehensive study has not yet been undertaken examining the immunological and predictive effects of TUBA1B in a pan-carcinoma context. Using data from TCGA, GEO, and other databases, we analyzed TUBA1B expression across various carcinoma types using transcriptional profiling, prognostic implications, genetic and epigenetic alterations, methylation patterns, and immunological significance. To validate our findings, we conducted Western blot analysis to assess TUBA1B protein levels in matched breast cancer tissue samples and performed CCK-8 proliferation assay, flow cytometry, transwell invasion, and migration assays to comprehensively examine the functional impact of TUBA1B on breast cancer cells. Our pan-cancer analysis found TUBA1B upregulation across most tumor types, with varying expression patterns in distinct immune and molecular subtypes. High TUBA1B expression was an independent risk factor and associated with poor prognoses in several cancers, including BRCA, KICH, LGG, LUAD, and MESO. TUBA1B also demonstrates moderate to high diagnostic accuracy in most tumor types. Increased m6A methylation levels were observed in the TUBA1B gene, while its promoter region displayed low methylation levels. TUBA1B's expression impacted some cancers by elevating tumor mutation burden, microsatellite instability, neoantigen formation, immune cell infiltration, and the modulation of immune checkpoints. Functional enrichment analysis highlights TUBA1B’s involvement in important cellular processes such as the cell cycle, p53 signaling, cell senescence, programmed cell death, and the regulation of immune-related pathways. Moreover, our study reveals higher TUBA1B protein expression in breast cancer tissues compared to adjacent tissues. In vitro experiments confirm that TUBA1B deletion reduces breast cancer cell proliferation, invasion, and migration while increasing apoptosis. In conclusion, our study suggests that TUBA1B could potentially serve as a diagnostic marker for predicting cancer immunological profiles and survival outcomes and shed light on the expression and role of TUBA1B in breast cancer, providing a solid foundation for considering it as a promising therapeutic target for breast cancer patient treatment.