Progression Of Breast Cancer Cells Research Articles

ZLM-7 Blocks Breast Cancer Progression by Inhibiting MDM2 via Upregulation of 14-3-3 Sigma

Breast cancer is one of the most prevalent malignancies with poor prognosis. Inhibition of angiogenesis is becoming a valid and evident therapeutic strategy to treat cancer. Recent studies uncovered the antiangiogenic activity of ZLM-7 (a combretastain A-4 derivative), but the regulatory mechanism is unclear. ZLM-7 treatment was applied in estrogen receptor-positive cell MCF-7, triple-negative breast cancer cell MDA-MB-231 and xenograft models. Transfections were conducted to overexpress or knockdown targeted genes. The gene and protein expressions were measured by qPCR and Western blotting assay, respectively. Cell proliferation and apoptosis were evaluated using the CCK8 method, clone formation assay and flow cytometry. We found that ZLM-7 upregulated 14-3-3 sigma expression but downregulated MDM2 expression in breast cancer cells. ZLM-7 delayed cell proliferation, promoted apoptosis and blocked cell-cycle progression in human breast cancer cells in vitro, while those effects were abolished by 14-3-3 sigma knockdown; overexpression of 14-3-3 sigma reproduced the actions of ZLM-7 on the cell cycle, which could be reversed by MDM2 overexpression. In xenograft models, ZLM-7 treatment significantly inhibited tumor growth while the inhibition was attenuated when 14-3-3 sigma was silenced. Collectively, ZLM-7 could inhibit MDM2 via upregulating 14-3-3 sigma expression, thereby blocking the breast cancer progression.

HIF‑1α and MBP1 are associated with the progression of breast cancer cells by repressing β‑catenin transcription.

Breast cancer (BC) is a common type of tumor. Numerous patients are diagnosed and treated in the early stages of the disease; however, the recurrence rate remains high. Therefore, identifying sensitive and specific tumor markers to prevent and treat BC is essential. c-Myc promoter binding protein 1 (MBP1) is a regulatory molecule located in the cell nucleus. It targets and regulates the expression of various cell proliferation-, apoptosis- and tumor-associated genes. MBP1 expression in BC tissues was detected using immunohistochemistry and further validated in BC and normal human cell lines using RT-qPCR and western blot analysis. Low MBP1 expression, in clinical samples of BC, was associated with a poor prognosis of BC (n=50). MBP1 overexpression effectively inhibited the growth and metastasis of xenograft tumors in vivo. Cell counting kit-8 assays confirmed that the proliferation of the BC cell lines was significantly increased following knockdown of MBP1 expression, while overexpression of MBP1 could significantly inhibit the proliferation of the BC cell lines. Mechanistically, a dual-luciferase assay was used to confirm that MBP1 was the key transcriptional regulator of β-catenin. In addition, MBP1 transcription and hypoxia-inducible factor (HIF-1α) induction were associated. By regulating the hypoxic microenvironmental state in the MDA231 and MCF7 cell lines, it was demonstrated that MBP1 served as a hypoxia-responsive factor and could be a new target for tumor therapy. Taken together, these results suggested that MBP1, as a potential tumor marker associated with prognosis of BC and may serve as a therapeutic target for BC. Moreover, MBP1 plays a critical role in inhibiting the growth and progression of BC cell lines.

SNHG6 203 RNA May be Involved in the Cell Cycle Progression in HER2-Negative Breast Cancer Cells

Background & Objective: Long noncoding RNAs (lncRNAs) as challenging molecules are more known compared to those in the last decade. These transcripts have been validated for carcinogenesis in many types of tissue. Functions of lncRNAs in cancer induction include cell cycle, epithelial to mesenchymal transition progression, apoptosis inhibition, cell migration, and invasion stimulation . LncRNA small nucleolar host (SNHG6) have been proven as an oncogenic transcript in many types of cancer.Methods: RNA extraction was performed for 47 breast specimens in patients with cancer and cDNAs were synthesized. Relative expression of target variants was determined by qPCR and calculated based on the ΔΔCt method. SNHG6 203 was cloned into pcDNA 3.1+ vector for overexpression in MCF7 (HER2-) and SK-BR3 (HER2+) cells. The cell cycle progression of transfected cells was assessed by flow cytometry. Cell migration ability of transfected cells was evaluated by the scratch method and Image J software. Finally, cell viability was assessed by the MTT method.Results: Among four splice variants of SNHG6 (202, 203, 204, and 207), SNHG6 203 was proved as an overexpressed splice variant in breast cancer tumors. This transcript was expressed in HER2-negative breast tumors more frequently than in the positive ones. Overexpression of this variant in target cells resulted in cell cycle progression of MCF7 as HER2-negative cells. Moreover, the overexpression of SNHG6 203 led to a lower migration ability of MCF7 cells and a non-significant reduction of their viability as HER2-negative breast cancer cells.

Breast cancer progression to other organs

Breast cancer has become very common among women and is the major cause of morbidity. The progression of breast cancer and the formation of secondary tumors in other organs is of major concern. Relapse and recurrence of breast cancer worsen the situation. Multiple genes get altered facilitating metastasis of cancer and downregulation/upregulation of many genes causes variations in molecular expression leading to progression in breast cancer cells. Mainly subtypes of breast cancer are distinct in the expression of hormone receptors (HR) and other proteins like ER, PR, HER2. Breast cancer can invade distant organs commonly in the bone, brain, lung, liver, and also the local region like the chest wall, and lymph nodes. Understanding the mechanism of cancer progression and molecules involved in breast cancer will help in developing therapies to prevent metastasis and find cures for breast cancer. In this review, the biomolecules such as ER, PR, HER2, etc. and the genes involved in breast cancer during its progression, and the mechanisms involved in metastasis have been discussed.

TRPC5OS induces tumorigenesis by increasing ENO1-mediated glucose uptake in breast cancer

Breast cancer is the most common malignant tumor worldwide and the leading cause of cancer-related deaths in female. Metabolic reprogramming plays critical roles in breast tumorigenesis and induces enhanced glucose uptake and glycolysis. TRPC5OS is encoded by short transient receptor potential channel 5 opposite strand, and predicted to correlate with tumor metabolic reprogramming. Here we aim to elucidate the function of TRPC5OS in aberrant metabolism mediated tumorigenesis. We detected TRPC5OS expression levels in cell lines and tissues by quantitative real-time polymerase chain reaction and immunohistochemistry. Then we assessed the effects of TRPC5OS on proliferation and cell cycle progression in breast cancer cells by cell counting kit-8, colony-formation, EdU-incorporation assays and flow cytometry. Tumor growth in vivo was observed in a mouse xenograft model. Mass spectrum analyses were performed to identify potential interactors of TRPC5OS in tumor cells, and the interaction between TRPC5OS and interactors was validated by co-immunoprecipitation (CO-IP), western blots, and immunofluorescent staining. Glucose uptake was measured by liquid scintillation spectrometry. TRPC5OS highly expresses both in breast tumors and cell lines, and might be an independent prognostic marker for breast cancer patients. Overexpressed TRPC5OS promotes breast cancer cell proliferation, cell cycle progression, and enhances tumor xenograft growth. Mass spectral and CO-IP data showed that TRPC5OS interacts with ENO1. We also demonstrate that TRPC5OS could enhance ENO1/PI3K/Akt-mediated glucose uptake in breast cancer cells. Our study demonstrated that TRPC5OS promotes breast tumorigenesis by ENO1/PI3K/Akt-mediated glucose uptake. TRPC5OS might be an independent prognostic marker and potential therapeutic target for breast cancer patients.

Knockdown of CDCA5 suppresses malignant progression of breast cancer cells by regulating PDS5A.

Breast cancer is one of the most common malignant tumors in women. Cell division cycle-associated 5 (CDCA5) is closely associated with the behavior of various cancer types. The aim of the present study was to explore the effect of CDCA5 on breast cancer. Western blot analysis and reverse transcription-quantitative PCR were used to detect the expression level of CDCA5 in human normal mammary cells and human breast cancer cell lines. To determine its function in MDA-MB-231 cells, CDCA5 was silenced in MDA-MB-231 cells by transient short hairpin RNA transfection. Cell Counting Kit-8 and clonogenicity assays were used to evaluate cell proliferation. Wound healing and Transwell assays were used to detect cell invasion and migration. Western blot analysis was used to detect the protein expressions of Ki67 and PCNA associated with proliferation, MMP2 and MMP9 associated with migration. CDCA5 was found to be markedly increased in breast cancer cell lines. CDCA5 knockdown was able to suppress cell proliferation, invasion and migration. CDCA5 inhibition downregulated PDS5 cohesin-associated factor A (PDS5A) expression in breast cancer cells. PDS5A overexpression was found to reverse the effect of CDCA5 inhibition on breast cancer cell proliferation and migration. CDCA5 knockdown was shown to suppress the malignant progression of breast cancer cells by regulating PDS5A. The present findings may provide new potential targets for breast cancer therapy.

Myocardin-related transcription factor's interaction with serum-response factor is critical for outgrowth initiation, progression, and metastatic colonization of breast cancer cells.

Breast cancer (BC)‐related mortality primarily results from metastatic colonization of disseminated cells. Actin polymerization plays an important role in driving post‐extravasation metastatic outgrowth of tumor cells. This study examines the role of myocardin‐related transcription factor (MRTF)/serum‐response (SRF), a transcription system well known for regulation of cytoskeletal genes, in metastatic colonization of BC cells. We demonstrated that co‐depletion of MRTF isoforms (MRTF‐A and MRTF‐B) dramatically impairs single‐cell outgrowth ability of BC cells as well as retards growth progression of pre‐established BC cell colonies in three‐dimensional (3D) cultures. Conversely, overexpression of MRTF‐A promotes initiation and progression of tumor‐cell outgrowth in vitro, primary tumor formation, and metastatic outgrowth of seeded BC cells in vivo, and these changes can be dramatically blocked by molecular disruption of MRTF‐A's interaction with SRF. Correlated with the outgrowth phenotypes, we further demonstrate MRTF's ability to augment the intrinsic cellular ability to polymerize actin and formation of F‐actin‐based protrusive structures requiring SRF's interaction. Pharmacological proof‐of‐concept studies show that small molecules capable of interfering with MRTF/SRF signaling robustly suppresses single‐cell outgrowth and progression of pre‐established outgrowth of BC cells in vitro as well as experimental metastatic burden of BC cells in vivo. Based on these data, we conclude that MRTF activity potentiates metastatic colonization of BC cells and therefore, targeting MRTF may be a promising strategy to diminish metastatic burden in BC.

Vitamin D: Structure and mechanism of action

Vitamin D has received more attention in recent years as a result of the resurgence of vitamin D deficiency and rickets as a global health issue, as well as compelling evidence in the laboratory indicating that 1,25-dihydroxy vitamin D3 [1,25(OH)2D3], the hormonally active form of vitamin D, generates several extraskeletal biological responses such as inhibition of breast, colon, and prostate cancer cell progression; effects on the cardiovascular system; and protects against. This review covers our present knowledge of vitamin D and its bioactivation, as well as fresh findings that have altered our understanding of vitamin D activity in both classical and nonclassical target tissues. This page also assesses vitamin D's alleged involvement in extraskeletal health, provides an overview of 1,25(OH)2D3 analogs that have been created, and highlights unanswered problems.

Nuclear Localization of Fibroblast Growth Factor Receptor 1 in Breast Cancer Cells Interacting with Cancer Associated Fibroblasts.

Cancer-associated fibroblasts (CAFs) represent a major component of the tumor microenvironment and interplay with cancer cells by secreting cytokines, growth factors and extracellular matrix proteins. When estrogen receptor-negative breast cancer MDA-MB-231 cells were treated with the CAF-conditioned medium (CAF-CM), Akt and STAT3 involved in cell proliferation and survival were activated through phosphorylation. CAFs secrete fibroblast growth factor 2 (FGF2), thereby stimulating breast cancer cell progression. Akt activation induced by CAF-CM in MDA-MB-231 cells was abolished when FGF2-neutralizing antibody was added. Treatment of MDA-MB-231 cells directly with FGF2 enhanced the phosphorylation of Akt and the FGF receptor (FGFR) substrate, FRS2α. These events were abrogated by siRNA-mediated silencing of FGFR1. In a xenograft mouse model, co-injection of MDA-MB-231 cells with activated fibroblasts expressing FGF2 dramatically enhanced activation of Akt. Stable knockdown of FGFR1 blunted Akt phosphorylation in xenograft tumors. MDA-MB-231 cells co-cultured with CAFs or directly stimulated with FGF2 exhibited enhanced nuclear localization of FGFR1. Notably, FGF2 stimulation produced reactive oxygen species (ROS) accumulation in MDA-MB-231 cells, and FGF2-induced nuclear accumulation of FGFR1 was abrogated by the ROS scavenging agent, N-acetylcysteine.

Bone marrow mesenchymal stem cells-derived exosomal microRNA-16-5p restrains epithelial-mesenchymal transition in breast cancer cells via EPHA1/NF-κB signaling axis

ObjectiveThis study intends to conquer the mystery of microRNA-16-5p/erythropoietin-producing hepatocellular A1/nuclear factor-κB signaling (miR-16-5p/EPHA1/NF-κB signaling) in breast cancer. MethodsExpression of miR-16-5p, EPHA1 and NF-κB signaling-related proteins were detected. Gene overexpression or silencing was used to examine the biological roles of bone marrow mesenchymal stem cells (BMSCs)-derived exo-miR-16-5p in breast cancer. The effect of exo-miR-16-5p on tumorigenesis of breast cancer was confirmed by the xenograft nude mouse model. ResultsLow miR-16-5p and high EPHA1 expression were examined in breast cancer. BMSCs-derived exosomes, up-regulated miR-16-5p or down-regulated EPHA1 restrained epithelial-mesenchymal transition (EMT) of breast cancer cells and tumor growth in nude mice. Down-regulated miR-16-5p or up-regulated EPHA1 activated NF-κB signaling. Knockdown of EPHA1 or inhibition of NF-κB signaling reversed the effects of down-regulated miR-16-5p on breast cancer cells. ConclusionBMSCs-derived exosomal miR-16-5p hinders breast cancer cells progression via EPHA1/NF-κB signaling axis.

Histone H2AX promotes metastatic progression by preserving glycolysis via hexokinase-2

Genomic stability is essential for organismal development, cellular homeostasis, and survival. The DNA double-strand breaks are particularly deleterious, creating an environment prone to cellular transformation and oncogenic activation. The histone variant H2AX is an essential component of the nucleosome responsible for initiating the early steps of the DNA repair process. H2AX maintains genomic stability by initiating a signaling cascade that collectively functions to promote DNA double-strand breaks repair. Recent advances have linked genomic stability to energetic metabolism, and alterations in metabolism were found to interfere with genome maintenance. Utilizing genome-wide transcripts profiling to identify differentially-expressed genes involved in energetic metabolism, we compared control and H2AX-deficient metastatic breast cancer cell lines, and found that H2AX loss leads to the repression of key genes regulating glycolysis, with a prominent effect on hexokinase-2 (HK2). These observations are substantiated by evidence that H2AX loss compromises glycolysis, effect which was reversed by ectopic expression of HK2. Utilizing models of experimental metastasis, we found that H2AX silencing halts progression of metastatic breast cancer cells MDA-MB-231. Most interestingly, ectopic expression of HK2 in H2AX-deficient cells restores their metastatic potential. Using multiple publicly available datasets, we found a significantly strong positive correlation between H2AX expression levels in patients with invasive breast cancer, and levels of glycolysis genes, particularly HK2. These observations are consistent with the evidence that high H2AX expression is associated with shorter distant metastasis-free survival. Our findings reveal a role for histone H2AX in controlling the metastatic ability of breast cancer cells via maintenance of HK2-driven glycolysis.

Abstract P5-11-03: Altered adipose-derived mesenchymal stem/stromal cells induced by obesity in the breast cancer microenvironment

Abstract It is well documented that obesity, characterized by an increased body mass index (BMI≥30), is an important risk factor for the development of aggressive breast cancer (BC), which is associated with a reduced overall survival rate and decreased treatment response. The tumor microenvironment (TME), a cellular network majorly constructed by adipocytes, adipose-derived mesenchymal stem/stromal cells (bASCs) and immune cells, impacts progression of breast cancer and treatment response of patients. This study aims to examine how obesity influences the functional characteristics of bASCs in comparison to lean bASCs in the TME. To address this issue, various molecular, biological and cellular methods are applied including transcriptomic profiling and functional assays to characterize at first the features of bASCs in the TME (adjacent to tumor; -aT/distant to tumor; -dT) in obese (ob-) and lean (ln-) bASCs (n=5, for each group) patients with breast cancer. Second, based on the transcriptomic data, we investigated the interaction of bASCs with triple negative as well as triple positive BC cell lines in 3D-spheroids and in standard 2D-cell culture conditions.Indicated by the gene signature the TME shifts bASCs towards a cancer supporting phenotype with a significant deregulated protein expression, cytokine/chemokine secretion, and reduced differentiation capacity. These changes affect critically the cell-cell interaction of BC cells with bASCs. bASCs isolated adjacent to the tumor increase the malignancy of BCs by stimulating the proliferation, migration, invasion and chemoresistance of these cells significantly. These observed effects are further enhanced by ob-aT bASCs. In conclusion, this study identifies over 900 genes deregulated in bASCs adjacent to breast cancer. Many of these genes are associated with pathways known for the development of malignant cells. Moreover, it clarifies differences in obese versus lean bASCs and their impacts on progression of breast cancer cells. Citation Format: Andreas Ritter, Susanne Roth, Alexandra Friemel, Nina-Naomi Kreis, Frank Louwen, Christine Solbach, Juping Yuan. Altered adipose-derived mesenchymal stem/stromal cells induced by obesity in the breast cancer microenvironment [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P5-11-03.

Abstract P5-12-07: Proteomic profiling of extracellular vesicles released from leptin-treated breast cancer cells: A potential role in cancer metabolism

Abstract Extracellular vesicles (EVs), nanosized particles enclosed within a phospholipid bilayer membrane, are recognized key determinants of cell-to-cell communication in breast cancer, able to modulate phenotypic behavior of recipient cells by transferring their molecular cargo. Recently, we identified the adipokine leptin, whose circulating levels are elevated in obesity, as an important regulator of EV biogenesis and release in mammary carcinoma cells. Here, we focused on the identification of a specific leptin-induced EV proteomic signature in attempt to find molecular effectors associated with breast cancer progression. To this end, we analyzed protein content of EVs, isolated by ultracentrifugation method from conditioned media of ER-α positive MCF-7 breast cancer cells grown in the presence of leptin. EVs were fully characterized using Transmission Electron Microscopy (TEM), Nanoparticle Tracking Analysis (NTA) and Immunoblotting. Proteomic analysis of EV cargo, obtained by liquid chromatography-tandem mass spectrometry analysis (LC-MS/MS), revealed an altered protein profile, identifying 274 up-regulated proteins (FC>1.5) in EVs from leptin-treated cells compared to EV from untreated ones. Gene set enrichment analysis (GSEA) was used to explore Gene Ontology categories enriched in the entire list of up-regulated proteins. We identified a number of significantly enriched biologic processes mainly involved in energy production and mitochondrial metabolism, including “generation of precursor metabolites and energy” (GO:0006091), “fatty acid metabolic process” (GO:0006631), “mitochondrial respiratory chain” (GO:0033108), “mitochondrial gene expression” (GO:0140053) and “mitochondrial transport” (GO:0006839). Expression of up-regulated proteins, in both cell and EV lysates, was validated by immunoblotting. Protein-protein interaction network analysis revealed CYC1 (Cytochrome c-1), NDUFV2 (NADH:ubiquinone oxidoreductase core subunit V2), and NDUFAB1 (NADH:ubiquinone oxidoreductase subunit AB1), important subunits of mitochondrial complexes and enhancer of mitochondrial metabolism, as the most interactive proteins among that up-regulated in EVs released by leptin-treated breast cancer cells. This suggests a role for leptin-treated EVs in enhancing oxidative phosphorylation in both epithelial breast cancer cells and their surrounding microenvironment. Collectively, our data indicate that the adipokine leptin could induce in breast cancer cells the release of EVs enriched in specific proteins mainly involved in mitochondrial metabolism. Since, mitochondrial function is essential for supplying energy to support breast cancer cell growth and progression, understanding the metabolic mechanisms mediated by EV released by breast cancer cells may provide important clues to develop novel therapeutic approaches for treatment of breast cancer especially in obesity setting. Citation Format: Luca Gelsomino, Giusi La Camera, Ines Barone, Salvatore Panza, Giovanna Morello, Amanda Caruso, Chiara Chiodo, Daniela Bonofiglio, Cinzia Giordano, Sebastiano Andò, Stefania Catalano. Proteomic profiling of extracellular vesicles released from leptin-treated breast cancer cells: A potential role in cancer metabolism [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P5-12-07.

DNMT1 facilitates growth of breast cancer by inducing MEG3 hyper-methylation

BackgroundTo understand the effect of DNMT1-mediated MEG3 promoter methylation on breast cancer progression.MethodsExpression of DNMT1, MEG3 and miR-494-3p was assayed by qRT-PCR and western blot. Methylation-specific PCR was used to examine MEG3 promoter methylation level. ChIP, RNA binding protein immunoprecipitation assay and dual-luciferase reporter gene assay were applied to verify interaction between DNMT1 and MEG3, miR-494-3p and MEG3 and OTUD4. CCK-8, wound healing and Transwell assays were used to detect biological functions of breast cancer cells. Tumor growth was observed by tumor xenograft model.ResultsDNMT1 and miR-494-3p were highly expressed while MEG3 and OTUD4 were lowly expressed in breast cancer cells. Knockdown of DNMT1 inhibited progression of breast cancer cells by enhance MEG3 expression through demethylation. MEG3 could downregulate miR-494-3p expression, and OTUD4 was a target of miR-494-3p. Upregulation of MEG3 and downregulation of miR-494-3p both inhibited malignant behavior of cells in vitro. In addition, high MEG3 expression restrained growth of breast cancer in vivo.ConclusionBriefly, our results demonstrated that, DNMT1 induced methylation of MEG3 promoter, and played a key role in breast cancer growth throughmiR-494-3p/OTUD4 axis. These findings provide new insights into molecular therapeutic targets for breast cancer.

Antitumorigenic Effect of Tramadol and Synergistic Effect With Doxorubicin in Human Breast Cancer Cells.

BackgroundBreast cancer in women is one of the leading causes of cancer mortality worldwide, and curative therapy is the main focus of clinical treatment. Anesthetic-analgesic techniques might alter stress responses and immunity and thereby influence outcomes in cancer patients. This study investigated the effect of tramadol on breast cancer progression and metastasis.MethodsThe effects of tramadol on two different subtypes of human breast adenocarcinoma cell lines, MDA-MB-231 and MCF-7, were studied with regard to cell growth, migration, colony formation and invasion and normoxic or hypoxic microenvironment for the expression of hypoxia-inducible factor-1α, reactive oxygen species, epithelial-mesenchymal transition related and cyclin-related proteins. The co-administration of tramadol and doxorubicin was studied to determine whether the effective doxorubicin dose might be reduced in combination with tramadol.ResultsThe results showed that tramadol inhibited cell growth at concentrations more than 0.5 and more than 1.0 mg/mL in MDA-MB-231 and MCF-7 cells, respectively. Additionally, cell migration, colony formation and invasion were inhibited in a dose-dependent manner by tramadol in both cell lines. The combination of tramadol and doxorubicin induced synergistic effects in MDA-MD-231 cells and, with specific dosage combinations in MCF-7 cells.ConclusionsTramadol may regulate epithelial-mesenchymal transition and possess cytotoxic effects in breast cancer cells. Tramadol inhibits the progression of breast cancer cells and might be a candidate for combination therapy, especially for triple-negative breast cancer, and is a promising treatment strategy for breast cancer.

Matrix Metalloproteinase Gene Variations And Expression Levels In Breast Cancer Development

Breast cancer is a heterogeneous disease and represents approximately 30% of all cancers in women. This type of cancer is one of the main causes of cancer-related deaths and is characterized by proliferation and metastasis of transformed cells. Extracellular matrix plays an important role in the growth, progression, prognosis, invasion and metastasis of breast cancer cells. Extracellular matrix degradation occurs by matrix metalloproteinases (MMPs) in invasive and metastatic breast cancers. MMPs are important proteolytic enzymes and are effective in tumor growth, invasion and metastasis. Various genetic variations have been identified in MMP genes and these genetic variations have been associated with changes in MMP enzyme activities, promoter activity, cell proliferation, and transcriptional regulation. Therefore, cell proliferation and tumor migration can be affected in breast cancer. Single nucleotide gene variations such as MMP-1, MMP-2, MMP-3, MMP-7, MMP-9 and MMP-12 have been associated with susceptibility to various cancer types such as breast cancer. The aim of this review is to provide general information about the pathogenesis of breast cancer as well as to examine the roles of MMP gene variations and expression levels in the development of breast cancer.

NR2F1-AS1 Acts as an Oncogene in Breast Cancer by Competitively Binding with miR-641.

Background Long noncoding RNA (lncRNA) NR2F1-AS1 has been previously reported to be dysregulated in human cancers and implicated in the tumorigenesis and development of tumors. In this research, we detected the expression level and biological function of NR2F1-AS1 in breast cancer (BC). Methods The expression of NR2F1-AS1 in BC tissues and cell lines was determined by qRT-PCR analysis. The associations of NR2F1-AS1 expression with clinical characteristics and survival rate of BC patients were also analyzed. Cell proliferation, migration, and invasion were measured by the CCK-8 and Transwell assay. Results The results revealed that the total survival time of BC patients with high NR2F1-AS1 expression was lower than that of BC patients with low NR2F1-AS1 expression. Moreover, functional experiments demonstrated that knockdown of NR2F1-AS1 inhibited BC cell viability, migration, and invasion abilities, whereas overexpression of NR2F1-AS1 had the opposite effect. Mechanistic investigation revealed that NR2F1-AS1 can competitively bind with microRNA-641 (miR-641) in BC. These results revealed that NR2F1-AS1 functioned as an oncogene by sponging miR-641 expression in BC cell progression. Moreover, miR-641 was negatively correlated with NR2F1-AS1 in BC tissues. Conclusion Hence, NR2F1-AS1 was found to act as an oncogene in breast cancer by suppressing miR-641. We suggested that NR2F1-AS1 could be a potential biomarker for BC diagnosis and therapy.

SNHG6 203 RNA May be Involved in the Cell Cycle Progression in HER2-Negative Breast Cancer Cells.

Background & Objective:Long noncoding RNAs (lncRNAs) as challenging molecules are more known than those in the last decade. These transcripts have been validated for carcinogenesis in many types of tissue. Functions of lncRNAs in cancer induction include cell cycle, epithelial to mesenchymal transition progression, apoptosis inhibition, cell migration, and invasion stimulation. LncRNA small nucleolar host gene 6 (SNHG6) have been proven as an oncogenic transcript in many types of cancer. Methods:RNA extraction was performed for 47 breast specimens in patients with cancer and cDNAs were synthesized. Relative expression of target variants was determined by qPCR and calculated based on the ΔΔCt method. SNHG6 203 was cloned into pcDNA 3.1+ vector for overexpression in MCF7 (HER2-) and SK-BR3 (HER2+) cells. The cell cycle progression of transfected cells was assessed by flow cytometry. Cell migration ability of transfected cells was evaluated by the scratch method and Image J software. Finally, cell viability was assessed by the MTT method.Results:Among four splice variants of SNHG6 (202, 203, 204, and 207), SNHG6 203 was proved as an overexpressed splice variant in breast tumors. This transcript was expressed in HER2-negative breast tumors more frequently than in the positive ones. Overexpression of this variant in target cells resulted in cell cycle progression of MCF7 as HER2-negative cells. Moreover, the overexpression of SNHG6 203 led to lower migration ability of MCF7 cells and a non-significant reduction of their viability as HER2-negative breast cancer cells. Conclusion:Our results revealed that SNHG6 203 may be involved in the carcinogenesis of HER2-negative breast cancers via cell cycle progression.

Oncogenic Long Noncoding RNA Linc01287 Promotes IGF1R Expression by Sponging miR-98 in Breast Cancer.

Long noncoding RNA (LncRNA) dysregulation has been shown to exhibit a regulatory effect in various cancers. However, the effect of LINC01287 on breast cancer (BC) has not been illustrated. The aim of this research was to explore the expression and function of LncRNA LINC01287 in BC. LINC01287 expression in clinical tissues and BC cell lines was detected. The luciferase reporter assay was performed to verify the correlation between LINC01287, microRNA 98 (miR-98), and the insulin-like growth factor 1 receptor (IGF1R). The CCK-8 assay was performed to examine cell viability. Cell invasion and migration capacity was determined by transwell and wound healing assays. The protein level of IGF1R, phosphorylated mitogen-activated protein kinase 1 and 2 (p-MEK1/2), and phosphorylated extracellular signal-regulated kinase 1 and 2 (p-ERK1/2) was analyzed by western blotting. LINC01287 expression markedly increased in BC cell lines. Subsequent studies identified LINC01287 as a downstream target of miR-98. In addition, LINC01287 knockdown and miR-98 overexpression significantly stagnated progression of BC cells. LINC01287 knockdown also downregulated IGF1R levels. Moreover, LINC01287 knockdown notably downregulated the phosphorylation of MEK1/2 and ERK1/2. The in vivo assay verified that LINC01287 can regulate tumorigenesis of BC. Our findings showed that LINC01287 was overexpressed in BC cells and tissues. LINC01287 promoted the malignant characteristics of BC cells and acted as an oncogene. Its regulatory effect may be associated with the miR-98/IGF1R/MEK/ERK signaling pathway. Therefore, LINC01287 has potential for use as a biomarker or therapeutic target for the treatment of BC.

MiR-135a-5p suppresses breast cancer cell proliferation, migration, and invasion by regulating BAG3

BackgroundMicroRNAs (miRNAs) are involved in the progression of diverse human cancers. This work aimed to delve into how microRNA-135a-5p (miR-135a-5p) affects the biological behaviors of Breast Cancer (BC) cells. MethodsGene Expression Omnibus (GEO) datasets were used to analyze the expression differences of miR-135a-5p in cancer tissues of BC patients. Quantitative real-time PCR and western blot were conducted to detect miR-135a-5p and Bcl-2 Associated Athanogene (BAG3) expression levels in BC tissues and cells, respectively. The proliferation, migration, invasion, and cell cycle of BC cells were detected by cell counting kit-8 assay, BrdU assay, wound healing assay, transwell assay, and flow cytometry. The targeted relationship between miR-135a-5p and BAG3 mRNA 3′UTR predicted by bioinformatics was further testified by a dual-luciferase reporter gene assay. Pearson's correlation analysis was adopted to analyze the correlation between miR-135a-5p expression and BAG3 expression. The downstream pathways of BAG3 were analyzed by the LinkedOmics database. ResultsMiR-135a-5p was significantly down-regulated and BAG3 expression was significantly raised in BC tissues. MiR-135a-5p overexpression repressed the viability, migration and invasion of BC cells, and blocked cell cycle progression in G0/G1 phase while inhibiting miR-135a-5p worked oppositely. BAG3 was verified as a target of miR-135a-5p. Overexpression of BAG3 reversed the impacts of miR-135a-5p on the malignant biological behaviors of BC cells. The high expression of BAG3 was associated with the activation of the cell cycle, mTOR and TGF-β signaling pathways. ConclusionMiR-135a-5p regulates BAG3 to repress the growth, migration, invasion, and cell cycle progression of BC cells.