cyclin-d1 and Triple-Negative-Breast-Neoplasms

To evaluate the prognostic role of elaborate molecular clusters encompassing cyclin D1, cyclin E1, p21, p27 and p53 in the context of various breast cancer subtypes.. Cyclin E1, cyclin D1, p53, p21 and p27 were evaluated with immunohistochemistry in 1077 formalin-fixed paraffin-embedded tissues from breast cancer patients who had been treated within clinical trials. Jaccard distances were computed for the markers and the resulted matrix was used for conducting unsupervised hierarchical clustering, in order to identify distinct groups correlating with prognosis.. Luminal B and triple-negative (TNBC) tumors presented with the highest and lowest levels of cyclin D1 expression, respectively. By contrast, TNBC frequently expressed Cyclin E1, whereas ER-positive tumors did not. Absence of Cyclin D1 predicted for worse OS, while absence of Cyclin E1 for poorer DFS. The expression patterns of all examined proteins yielded 3 distinct clusters; (1) Cyclin D1 and/or E1 positive with moderate p21 expression; (2) Cyclin D1 and/or E1, and p27 positive, p53 protein negative; and, (3) Cyclin D1 or E1 positive, p53 positive, p21 and p27 negative or moderately positive. The 5-year DFS rates for clusters 1, 2 and 3 were 70.0%, 79.1%, 67.4% and OS 88.4%, 90.4%, 78.9%, respectively.. It seems that the expression of cell cycle regulators in the absence of p53 protein is associated with favorable prognosis in operable breast cancer.

Topics: Adult; Aged; Antineoplastic Agents; Breast; Breast Neoplasms; Cyclin D1; Cyclin E; Cyclin-Dependent Kinase Inhibitor p21; Cyclin-Dependent Kinase Inhibitor p27; Female; Humans; Immunohistochemistry; Middle Aged; Oncogene Proteins; Prognosis; Survival Analysis; Triple Negative Breast Neoplasms; Tumor Suppressor Protein p53; Young Adult

Triple-negative breast cancer (TNBC) is the most aggressive form of breast cancer, accounting for 20% of cases. Due to the lack of a molecular target, limited options are available for TNBC treatment. Radiation therapy (RT) is a treatment modality for the management of TNBC following surgery; however, it has a detrimental effect on surrounding healthy tissues/cells at a higher rate.. We examined the effect of RT in combination with chrysin as a possible radiosensitizing agent in an MDA-MB-231 cell line as a model of a TNBC. The growth inhibitory effects of chrysin were examined using an MTT assay. Flow cytometry was performed to evaluate apoptosis and expression of hypoxia-induced factor-1α (HIF-1α). The protein expression of p-STAT3/STAT3 and Cyclin D1 was examined using western blotting. Real-time PCR determined apoptotic-related genes (Bax, BCL2, p53).. Treatment of MDA-MB-231 cells with chrysin in combination with RT caused synergistic antitumor effects, with an optimum combination index (CI) of 0.495. Our results indicated that chrysin synergistically potentiated RT-induced apoptosis in MDA-MB-231 compared with monotherapies (chrysin and/or RT alone). Expression of HIF-1α was decreased in the cells exposed to combinational therapy. The apoptotic effect of combinational therapy was correlated with increased Bax (pro-apoptotic gene) and p53 levels along with reduced expression of Bcl-2 (anti-apoptotic gene). Increased apoptosis was associated with reduced expression of Cyclin D1, p-STAT3.. These findings highlight the potential effect of chrysin as a radiosensitizer, indicating the synergistic anti-cancer effect of chrysin and RT in TNBC. Further investigation is warranted in this regard.

Topics: Apoptosis; bcl-2-Associated X Protein; Cell Line, Tumor; Cell Proliferation; Cyclin D1; Humans; Triple Negative Breast Neoplasms; Tumor Suppressor Protein p53

The anticancer effects of ruxolitinib and calcitriol against breast cancer were reported previously. However, the effect of ruxolitinib and calcitriol combination treatment on various molecular subtypes of breast cancer remains unexplored. In this study, we used MCF-7, SKBR3, and MDA-MB-468 cells to investigate the effect of ruxolitinib and calcitriol combination treatment on cell proliferation, apoptosis, cell cycle, and cell signaling markers, in vitro and in vivo. Our results revealed the synergistic anticancer effect of ruxolitinib and calcitriol combination treatment in SKBR3 and MDA-MB-468 cells, but not in MCF-7 cells in vitro, via cell proliferation inhibition, apoptosis induction, cell cycle arrest, and the alteration of cell signaling protein expression, including cell cycle-related (cyclin D1, CDK1, CDK4, p21, and p27), apoptosis-related (c-caspase and c-PARP), and cell proliferation-related (c-Myc, p-p53, and p-JAK2) proteins. Furthermore, in the MDA-MB-468 xenograft mouse model, we demonstrated the synergistic antitumor effect of ruxolitinib and calcitriol combination treatment, including the alteration of c-PARP, cyclin D1, and c-Myc expression, without significant drug toxicity. The combination exhibited a synergistic effect in HER2-enriched and triple-negative breast cancer subtypes. In conclusion, our results suggest different effects of the combination treatment of ruxolitinib and calcitriol depending on the molecular subtype of breast cancer.

Topics: Animals; Apoptosis; Breast Neoplasms; Calcitriol; Cell Line, Tumor; Cell Proliferation; Cyclin D1; Female; Humans; Mice; Nitriles; Poly(ADP-ribose) Polymerase Inhibitors; Pyrazoles; Pyrimidines; Triple Negative Breast Neoplasms

To investigate the effect of. Compared with those in the model group, the tumor-bearing mice receiving treatments with CHGZD showed significantly increased food intake with good general condition, sensitive responses, increased body weight, and lower tumor mass (. CHGZD combined with capecitabine can significantly inhibit tumor growth in nude mice bearing triple-negative breast cancer xenografts, the mechanism of which may involve the inhibition of IL-6/STAT3 signaling pathway and regulation of Bax, Bcl-2 and cyclin D1 expressions to suppress tumor cell proliferation and differentiation and induce cell apoptosis.

Topics: Animals; bcl-2-Associated X Protein; Capecitabine; Cyclin D1; Drugs, Chinese Herbal; Heterografts; Humans; Interleukin-6; Mice; Mice, Nude; Proto-Oncogene Proteins c-bcl-2; RNA, Messenger; Signal Transduction; STAT3 Transcription Factor; Triple Negative Breast Neoplasms

Triple-negative breast cancer (TNBC) is one of the most aggressive subtypes of breast cancer. TNBC lacks targeted therapy receptors, rendering endocrine and HER2-targeted therapies ineffective. TNBC is typically treated with cytotoxic chemotherapy followed by surgery. Targeting epigenetic modifications could potentially be a new effective TNBC target therapy. The aim of this study is to examine the effects of epigenetic drugs, decitabine as DNA methyltransferase inhibitor (DNMTI) and vorinostat as histone deacetylase inhibitor (HDACI), and the ERβ agonist DPN on ERα and ERβ re-expressions in the MDA-MB-231 cells as a model of TNBC.. Using MTT assay, the IC. Both ERα and ERβ mRNA were re-expressed in different high levels in all treated groups, especially in the triple therapy group compared with control. Significantly, the triple drugs therapy showed the lowest levels of VEGF, Cyclin D1, and IGF-1 and the highest level of Caspase-3 activity, indicating a possible antitumor effect of ERβ activation through decreasing proliferation and angiogenesis and increasing apoptosis in MDA-MB-231 cells.. The antiproliferative effect of ERβ could be retained when co-expressed with Erα using a powerful epigenetic combination of Decitabine and vorinostat with DPN.

Topics: Caspase 3; Cell Line, Tumor; Cell Proliferation; Cyclin D1; Decitabine; Epigenesis, Genetic; Estrogen Receptor alpha; Estrogen Receptor beta; Humans; Insulin-Like Growth Factor I; Nitriles; Propionates; Triple Negative Breast Neoplasms; Vascular Endothelial Growth Factor A; Vorinostat

Triple-negative breast cancer (TNBC) is an aggressive type of breast cancer and associated with poor prognosis and shorter survival due to significant genetic heterogeneity, drug resistance and lack of effective targeted therapeutics. Therefore, novel molecular targets and therapeutic strategies are needed to improve patient survival. Serotonin (5-hydroxytryptamine, 5-HT) has been shown to induce growth stimulatory effects in breast cancer. However, the molecular mechanisms by which 5-HT exerts its oncogenic effects in TNBC still are not well understood.. Normal breast epithelium (MCF10A) and two TNBC cells (MDA-MB-231, BT-546) and MCF-7 cells (ER +) were used to investigate effects of 5-HT7 receptor. Small interfering RNA (siRNA)-based knockdown and metergoline (5-HT7 antagonist) were used to inhibit the activity of 5-HT7. Cell proliferation and colony formation were evaluated using MTS cell viability and colony formation assays, respectively. Western blotting was used to investigate 5-HT7, FOXM1 and its downstream targets protein expressions.. We demonstrated that 5-HT induces cell proliferation of TNBC cells and expression of 5-HT7 receptor and FOXM1 oncogenic transcription factor. We found that expression of 5-HT7 receptor is up-regulated in TNBC cells and higher 5-HT7 receptor expression is associated with poor patient prognosis and shorter patient survival. Genetic and pharmacological inhibition of 5-HT7 receptor by siRNA and metergoline, respectively, suppressed TNBC cell proliferation and FOXM1 and its downstream mediators, including eEF2-Kinase (eEF2K) and cyclin-D1.. Our findings suggest for the first time that the 5-HT7 receptor promotes FOXM1, eEF2K and cyclin D1 signaling to support TNBC cell proliferation; thus, inhibition of 5-HT7 receptor/FOXM1 signaling may be used as a potential therapeutic strategy for targeting TNBC. 5-HT induces cell proliferation of TNBC cells through 5-HT7 receptor signaling. Also, genetic and pharmacological inhibition of 5-HT7 by RNAi (siRNA) and metergoline HTR7 antagonist, respectively inhibits FOXM1 oncogenic transcription factor and suppresses TNBC cell proliferation.

Topics: Biomarkers; Carcinogenesis; Cell Line, Tumor; Cell Proliferation; Cyclin D1; Forkhead Box Protein M1; Gene Expression Regulation, Neoplastic; Humans; Metergoline; Prognosis; RNA, Small Interfering; Serotonin; Transcription Factors; Triple Negative Breast Neoplasms

Emerging evidence suggests that breast cancer stem cells (BCSCs), and epithelial-mesenchymal transition (EMT) may be involved in resistance to doxorubicin. However, it is unlear whether the doxorubicin-induced EMT and expansion of BCSCs is related to cancer dormancy, or outgrowing cancer cells with maintaining resistance to doxorubicin, or whether the phenotypes can be transferred to other doxorubicin-sensitive cells. Here, we characterized the phenotype of doxorubicin-resistant TNBC cells while monitoring the EMT process and expansion of CSCs during the establishment of doxorubicin-resistant MDA-MB-231 human breast cancer cells (DRM cells). In addition, we assessed the potential signaling associated with the EMT process and expansion of CSCs in doxorubicin-resistance of DRM cells. DRM cells exhibited morphological changes from spindle-shaped MDA-MB-231 cells into round-shaped giant cells. They exhibited highly proliferative, EMT, adhesive, and invasive phenotypes. Molecularly, they showed up-regulation of Cyclin D1, mesenchymal markers (β-catenin, and N-cadherin), MMP-2, MMP-9, ICAM-1 and down-regulation of E-cadherin. As the molecular mechanisms responsible for the resistance to doxorubicin, up-regulation of EGFR and its downstream signaling, were suggested. AKT and ERK1/2 expression were also increased in DRM cells with the advancement of resistance to doxorubicin. Furthermore, doxorubicin resistance of DRM cells can be transferred by autocrine signaling. In conclusion, DRM cells harbored EMT features with CSC properties possessing increased proliferation, invasion, migration, and adhesion ability. The doxorubicin resistance, and doxorubicin-induced EMT and CSC properties of DRM cells, can be transferred to parental cells through autocrine signaling. Lastly, this feature of DRM cells might be associated with the up-regulation of EGFR.

Topics: Antibiotics, Antineoplastic; Antigens, CD; Autocrine Communication; beta Catenin; Cadherins; Cell Line, Tumor; Cell Movement; Cell Proliferation; Cyclin D1; Doxorubicin; Drug Resistance, Neoplasm; Epithelial Cells; Epithelial-Mesenchymal Transition; ErbB Receptors; Female; Gene Expression Regulation, Neoplastic; Humans; Intercellular Adhesion Molecule-1; Matrix Metalloproteinase 2; Matrix Metalloproteinase 9; Mitogen-Activated Protein Kinase 1; Mitogen-Activated Protein Kinase 3; Neoplastic Stem Cells; Proto-Oncogene Proteins c-akt; Signal Transduction; Triple Negative Breast Neoplasms

Despite the continuously growing repertoire of new and improved anti-cancer therapies, triple-negative breast cancer (TNBC) remains a clinical challenge to treat. In this sense, targeting signaling pathways such as Notch and Wnt/β-catenin have attracted growing attention. This work aimed at investigating the possible antitumor effects of IMR-1 as a Notch inhibitor, PRI-724 as a Wnt/β-catenin inhibitor, as well as their combination and to explore the possible crosstalk between Notch and Wnt/β-catenin signaling pathways in MDA-MB-231 TNBC cell line. Microculture tetrazolium test (MTT) was used to determine the drug growth inhibition (GI50), and the results were analyzed using CompuSyn 3.0.1 software. MDA-MB-231 cells were divided into four treatment groups including positive control, IMR-1-treated, PRI-724-treated, and combination-treated groups. Sandwich enzyme-linked immunosorbent assay (ELISA) was used for the determination of the protein levels of hairy and enhancer of split-1 (HES-1), Notch-1, β-catenin, cyclin-D1, and vascular endothelial growth factor (VEGF1). HES-1 gene expression was assessed by quantitative real-time polymerase chain reaction. Statistical analyses were performed using GraphPad Prism Software. The GI50 for IMR-1 and PRI-724 were 15.3 μM and 0.69 μM, respectively. Upon treatment of MDA-MB-231 cells with these drugs, HES-1 gene expression was up-regulated due to single and combined treatments. Moreover, the protein levels of cyclin-D1, VEGF1, HES-1, and Notch-1 were reduced, while those of active β-catenin and active caspase-3 were elevated. IMR-1/PRI-724 combination augmented IMR-1- and PRI-724-mediated effects on MDA-MB-231 cells by initiating apoptotic cell death. Further in vitro and in vivo studies are warranted to support our findings.

Topics: Antineoplastic Agents; Apoptosis; beta Catenin; Bridged Bicyclo Compounds, Heterocyclic; Caspase 3; Cell Line, Tumor; Cell Proliferation; Cyclin D1; Drug Interactions; Humans; Pyrimidinones; Receptor, Notch1; Thiazolidines; Transcription Factor HES-1; Triple Negative Breast Neoplasms; Vascular Endothelial Growth Factor A; Wnt Signaling Pathway

Triple-negative breast cancer (TNBC) is the most aggressive subtype with the worst prognosis and the highest metastatic and recurrence potential, which represents 15-20% of all breast cancers in Chinese females, and the 5-year overall survival rate is about 80% in Chinese women. Recently, emerging evidence suggested that aberrant alternative splicing (AS) plays a crucial role in tumorigenesis and progression. AS is generally controlled by AS-associated RNA binding proteins (RBPs). Monocyte chemotactic protein induced protein 1 (MCPIP1), a zinc finger RBP, functions as a tumor suppressor in many cancers. Here, we showed that MCPIP1 was downregulated in 80 TNBC tissues and five TNBC cell lines compared to adjacent paracancerous tissues and one human immortalized breast epithelial cell line, while its high expression levels were associated with increased overall survival in TNBC patients. We demonstrated that MCPIP1 overexpression dramatically suppressed cell cycle progression and proliferation of TNBC cells in vitro and repressed tumor growth in vivo. Mechanistically, MCPIP1 was first demonstrated to act as a splicing factor to regulate AS in TNBC cells. Furthermore, we demonstrated that MCPIP1 modulated NFIC AS to promote CTF5 synthesis, which acted as a negative regulator in TNBC cells. Subsequently, we showed that CTF5 participated in MCPIP1-mediated antiproliferative effect by transcriptionally repressing cyclin D1 expression, as well as downregulating its downstream signaling targets p-Rb and E2F1. Conclusively, our findings provided novel insights into the anti-oncogenic mechanism of MCPIP1, suggesting that MCPIP1 could serve as an alternative treatment target in TNBC.

Topics: Alternative Splicing; Breast; Carcinogenesis; Cell Line, Tumor; Cell Proliferation; Cell Transformation, Neoplastic; Cyclin D1; Gene Expression Regulation, Neoplastic; Genes, Tumor Suppressor; Humans; Neoplasm Recurrence, Local; NFI Transcription Factors; Ribonucleases; Transcription Factors; Triple Negative Breast Neoplasms

Circular RNAs (circRNAs) are increasingly gaining importance and attention due to their diverse potential functions and their value as diagnostic biomarkers (disease specific). This study aims to explore the novel mechanisms by which exosome-contained circRNAs promote tumor development and metastasis in TNBC. We identified increased circRNA circPSMA1 in TNBC cells, their exosomes, and serum exosomes samples from TNBC patients. The overexpression of circPSMA1 promoted TNBC cell proliferation, migration, and metastasis both in vitro and in vivo. Moreover, we investigated the tumor-infiltrating immune cells (TICs) or stromal components in immune microenvironment (IME), and identified the significant differences in the immune cells between TNBC and non-TNBC samples. Mechanistically, circPSMA1 acted as a "miRNAs sponge" to absorb miR-637; miR-637 inhibited TNBC cell migration and metastasis by directly targeted Akt1, which recognized as a key immune-related gene and affected downstream genes β-catenin and cyclin D1. Subsequent co-culture experiments also demonstrated that exosomes from TNBC carrying large amounts of circPSMA1 could transmit migration and proliferation capacity to recipient cells. Kaplan-Meier plots showed that high expression of Akt1 and low expression of mir-637 are highly correlated with poor prognosis in patients with lymph node metastasis of TNBC. Collectively, all these results reveal that circPSMA1 functions as a tumor promoter through the circPSMA1/miR-637/Akt1-β-catenin (cyclin D1) regulatory axis, which can facilitate the tumorigenesis, metastasis, and immunosuppression of TNBC. Our research proposes a fresh perspective on novel potential biomarkers and immune treatment strategies for TNBC.

Topics: beta Catenin; Carcinogenesis; Cell Movement; Cyclin D1; Exosomes; Humans; MicroRNAs; Neoplasm Metastasis; Proteasome Endopeptidase Complex; Proto-Oncogene Proteins c-akt; RNA, Circular; Triple Negative Breast Neoplasms; Tumor Microenvironment

The eukaryotic elongation factor-2 kinase, eEF2K, which restricts protein translation elongation, has been identified as a potential therapeutic target for diverse types of malignancies including triple negative breast cancer (TNBC). However, the contexts in which eEF2K inhibition is essential in TNBC and its consequences on the proteome are largely unknown. Here we show that genetic or pharmacological inhibition of eEF2K cooperated with glutamine (Gln) starvation, and synergized with glutaminase (GLS1) inhibitors to suppress growth of diverse TNBC cell lines. eEF2K inhibition also synergized with depletion of eukaryotic translation initiation factor 4E-binding protein 1 (eIF4EBP1; 4EBP1), a suppressor of eukaryotic protein translation initiation factor 4E (eIF4E), to induce c-MYC and Cyclin D1 expression, yet attenuate growth of TNBC cells. Proteomic analysis revealed that whereas eEF2K depletion alone uniquely induced Cyclin Dependent Kinase 1 (CDK1) and 6 (CDK6), combined depletion of eEF2K and 4EBP1 resulted in overlapping effects on the proteome, with the highest impact on the 'Collagen containing extracellular matrix' pathway (e.g. COL1A1), as well as the amino-acid transporter, SLC7A5/LAT1, suggesting a regulatory loop via mTORC1. In addition, combined depletion of eEF2K and 4EBP1 indirectly reduced the levels of IFN-dependent innate immune response-related factors. Thus, eEF2K inhibition triggers cell cycle arrest/death under unfavourable metabolic conditions such as Gln-starvation/GLS1 inhibition or 4EBP1 depletion, uncovering new therapeutic avenues for TNBC and underscoring a pressing need for clinically relevant eEF2K inhibitors.

Topics: Adaptor Proteins, Signal Transducing; Antineoplastic Combined Chemotherapy Protocols; Benzeneacetamides; Cell Cycle Proteins; Cell Line, Tumor; Cyclin D1; Cyclopentanes; Drug Synergism; Elongation Factor 2 Kinase; Female; Gene Silencing; Glutaminase; Humans; Protein Kinase Inhibitors; Proteins; Proto-Oncogene Proteins c-myc; Sulfides; Thiadiazoles; Triple Negative Breast Neoplasms

Topics: Antineoplastic Agents; Apoptosis; Autophagy-Related Proteins; Cell Line, Tumor; Cell Movement; Cell Proliferation; Cellular Senescence; Coordination Complexes; Cyclin D1; Humans; L-Lactate Dehydrogenase; Molecular Conformation; Platinum; Proto-Oncogene Proteins c-bcl-2; Pyruvate Kinase; Receptor, ErbB-2; Signal Transduction; Triple Negative Breast Neoplasms; Ubiquitin-Conjugating Enzymes

Triple negative breast cancer (TNBC) is a heterogeneous disease, which lacks expression of the estrogen receptor (ER), progesterone receptor (PR) and the human epidermal growth factor 2 receptor (HER2). This subtype of breast cancer has the poorest prognosis with limited therapies currently available, and hence additional options are needed. CAPER is a coactivator of the activator protein-1 (AP-1) (interacting specifically with the c-Jun component) and the ER and is known to be involved in human breast cancer pathogenesis. Recent published data have demonstrated a role for CAPER in TNBC and, as such, disrupting the function of CAPER with c-Jun could be a novel approach to treat TNBC patients. The data presented here shows the development and

Topics: Amino Acid Sequence; Apoptosis; Carcinogenesis; Cell Count; Cell Cycle; Cell Line, Tumor; Cell Nucleus; Cell Survival; Cyclin D1; Cyclin-Dependent Kinase Inhibitor p21; Histones; Humans; Neoplasm Proteins; Peptides; Phosphorylation; Protein Binding; Proto-Oncogene Proteins c-bcl-2; Proto-Oncogene Proteins c-jun; Recombinant Proteins; Triple Negative Breast Neoplasms

We investigated the function of circular RNA circEIF3M (hsa_circ_0003119) in triple-negative breast cancer. The expression profiles of circRNAs in 3 specimens of triple-negative breast cancer tissues with adjacent nontumor tissues were analyzed by RNA-sequencing. We verified the oncogenic role of circEIF3M in triple-negative breast cancer through a series of biological function experiments. It was found that circEIF3M was markedly upregulated in triple-negative breast cancer as compared to adjacent nontumor tissue, and that circEIF3M promoted triple-negative breast cancer cell proliferation, migration, and invasion. Mechanistic analysis indicated that circEIF3M may act as a competing endogenous RNA for miR-33a that relieves the inhibitory effect of miR-33a on its target cyclin D1. These findings showed that circEIF3M promotes triple-negative breast cancer progression via the circEIF3M/ miR-33a/ cyclin D1 axis.

Topics: Breast Neoplasms; Cell Line, Tumor; Cell Movement; Cell Proliferation; Cyclin D1; Disease Progression; Female; Gene Expression Regulation, Neoplastic; Humans; MicroRNAs; Neoplasm Invasiveness; RNA, Circular; Triple Negative Breast Neoplasms

Topics: Aminopyridines; Animals; Apoptosis; Cell Cycle Checkpoints; Cell Line, Tumor; Cell Movement; Cell Proliferation; Cyclin D1; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase 6; Cyclin-Dependent Kinase Inhibitor Proteins; E2F1 Transcription Factor; Female; Humans; Male; Mammary Neoplasms, Experimental; Mice; Mice, Nude; Phosphorylation; Purines; Retinoblastoma Protein; Triple Negative Breast Neoplasms; Tumor Burden

Proton therapy offers a distinct physical advantage over conventional X-ray therapy, but its biological advantages remain understudied. In this study, we aimed to identify genetic factors that contribute to proton sensitivity in breast cancer (BC). Therefore, we screened relative biological effectiveness (RBE) of 230 MeV protons, compared to 6 MV X-rays, in ten human BC cell lines, including five triple-negative breast cancer (TNBC) cell lines. Clonogenic survival assays revealed a wide range of proton RBE across the BC cell lines, with one out of ten BC cell lines having an RBE significantly different from the traditional generic RBE of 1.1. An abundance of cyclin D1 was associated with proton RBE. Downregulation of RB1 by siRNA or a CDK4/6 inhibitor increased proton sensitivity but not proton RBE. Instead, the depletion of cyclin D1 increased proton RBE in two TNBC cell lines, including MDA-MB-231 and Hs578T cells. Conversely, overexpression of cyclin D1 decreased the proton RBE in cyclin D1-deficient BT-549 cells. The depletion of cyclin D1 impaired proton-induced RAD51 foci formation in MDA-MB-231 cells. Taken together, this study provides important clues about the cyclin D1-CDK4-RB1 pathway as a potential target for proton beam therapy in TNBC.

Topics: Cell Line, Tumor; Cell Survival; Cyclin D1; Female; Gene Expression Regulation, Neoplastic; Humans; MCF-7 Cells; Proton Therapy; Radiation Tolerance; Relative Biological Effectiveness; Signal Transduction; Triple Negative Breast Neoplasms; X-Rays

Chromatin loops enable transcription-factor-bound distal enhancers to interact with their target promoters to regulate transcriptional programs. Although developmental transcription factors such as active forms of Notch can directly stimulate transcription by activating enhancers, the effect of their oncogenic subversion on the 3D organization of cancer genomes is largely undetermined. By mapping chromatin looping genome-wide in Notch-dependent triple-negative breast cancer and B cell lymphoma, we show that beyond the well-characterized role of Notch as an activator of distal enhancers, Notch regulates its direct target genes by instructing enhancer repositioning. Moreover, a large fraction of Notch-instructed regulatory loops form highly interacting enhancer and promoter spatial clusters termed "3D cliques." Loss- and gain-of-function experiments show that Notch preferentially targets hyperconnected 3D cliques that regulate the expression of crucial proto-oncogenes. Our observations suggest that oncogenic hijacking of developmental transcription factors can dysregulate transcription through widespread effects on the spatial organization of cancer genomes.

Topics: Binding Sites; Cell Lineage; Cell Proliferation; Cell Transformation, Neoplastic; Chromatin; Chromatin Assembly and Disassembly; Cyclin D1; Enhancer Elements, Genetic; Gene Expression Regulation, Neoplastic; Gene Regulatory Networks; HEK293 Cells; Humans; Lymphoma, B-Cell; Mutation; Nucleic Acid Conformation; Oncogenes; Promoter Regions, Genetic; Protein Binding; Proto-Oncogene Proteins c-myc; Receptors, Notch; Signal Transduction; Triple Negative Breast Neoplasms

Triple negative breast cancer (TNBC) is the most lethal and aggressive subtype of breast cancer. AMP-activated protein kinase (AMPK) is a major energy regulator that suppresses tumor growth, and 1-(3-chloro-4-((trifluoromethyl)thio)phenyl)-3-(4-(trifluoromethoxy)phenyl)urea (FND-4b) is a novel AMPK activator that inhibits growth and induces apoptosis in colon cancer. The purpose of this project was to test the effects of FND-4b on AMPK activation, proliferation, and apoptosis in breast cancer with a particular emphasis on TNBC.. (i) Estrogen-receptor positive breast cancer (ER+BC; MCF-7, and T-47D), TNBC (MDA-MB-231 and HCC-1806), and breast cancer stem cells were treated with FND-4b for 24h. Immunoblot analysis assessed AMPK, acetyl-CoA carboxylase (ACC), ribosomal protein S6, cyclin D1, and cleaved PARP. (ii) Sulforhodamine B growth assays were performed after treating ER+BC and TNBC cells with FND-4b for 72h. Proliferation was also assessed by counting cells after 72h of FND-4b treatment. (iii) Cell death ELISA assays were performed after treating ER+BC and TNBC cells with FND-4b for 72h.. (i) FND-4b increased AMPK activation with concomitant decreases in ACC activity, phosphorylated S6, and cyclin D1 in all subtypes. (ii) FND-4b decreased proliferation in all cells, while dose-dependent growth decreases were found in ER+BC and TNBC. (iii) Increases in apoptosis were observed in ER+BC and the MDA-MB-231 cell line with FND-4b treatment.. Our findings indicate that FND-4b decreases proliferation for a variety of breast cancers by activating AMPK and has notable effects on TNBC. The growth reductions were mediated through decreases in fatty acid synthesis (ACC), mTOR signaling (S6), and cell cycle flux (cyclin D1). ER+BC cells were more susceptible to FND-4b-induced apoptosis, but MDA-MB-231 cells still underwent apoptosis with higher dose treatment. Further development of FND compounds could result in a novel therapeutic for TNBC.

Topics: Acetyl-CoA Carboxylase; AMP-Activated Protein Kinases; Cell Line, Tumor; Cell Proliferation; Cell Survival; Cyclin D1; Enzyme Activation; Female; Gene Expression Regulation, Neoplastic; Humans; MCF-7 Cells; Phenylurea Compounds; Poly(ADP-ribose) Polymerases; Receptors, Estrogen; Ribosomal Protein S6; Triple Negative Breast Neoplasms

Circular RNAs (circRNAs) play critical roles in tumorigenesis. In the present study, we aimed to explore the potential regulatory mechanism of circRNA_069718 in triple-negative breast cancer (TNBC).. CircRNA_069718 expression levels in TNBC tissues and cell lines were determined by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). In vitro function assays were used to determine the functional roles of circRNA_069718 in TNBC and were explored by Cell Counting Kit-8 (CCK-8) assay, colony formation assay, transwell assay, and flow cytometric analysis. QRT-PCR and Western blot were used to explore the effects of circRNA_0023642 on the expression of Wnt/β-catenin pathway-related genes.. We found that circRNA_069718 expression was significantly increased in TNBC tissues and cell lines. High circRNA_069718 expression was significantly correlated with advanced TNM stage, lymph node metastasis, and poor overall survival of TNBC patients. Functionally, we showed that circRNA_069718 inhibition significantly reduced TNBC cells proliferation and invasion ability in vitro. Mechanically, we found that circRNA_069718 inhibition reduced the expression levels of Wnt/β-catenin pathway-related genes (β-catenin, c-myc, and cyclin D1).. Our findings suggested that circRNA_069718 promoted TNBC progression via Wnt/β-catenin pathway and could serve as a novel therapeutic target for TNBC treatment.

Topics: beta Catenin; Breast; Cell Line, Tumor; Cell Movement; Cell Proliferation; Cyclin D1; Disease Progression; Female; Gene Expression Regulation, Neoplastic; Humans; Kaplan-Meier Estimate; Mastectomy; Middle Aged; Neoplasm Staging; Prognosis; Proto-Oncogene Proteins c-myc; RNA, Circular; Triple Negative Breast Neoplasms; Wnt Signaling Pathway

The protein C receptor (PROCR) has emerged as a stem cell marker in several normal tissues and has also been implicated in tumor progression. However, the functional role of PROCR and the signaling mechanisms downstream of PROCR remain poorly understood. Here, we dissected the PROCR signaling pathways in breast cancer cells. Combining protein array, knockdown, and overexpression methods, we found that PROCR concomitantly activates multiple pathways. We also noted that PROCR-dependent ERK and PI3k-Akt-mTOR signaling pathways proceed through Src kinase and transactivation of insulin-like growth factor 1 receptor (IGF-1R). These pathway activities led to the accumulation of c-Myc and cyclin D1. On the other hand, PROCR-dependent RhoA-ROCK-p38 signaling relied on coagulation factor II thrombin receptor (F2R). We confirmed these findings in primary cells isolated from triple-negative breast cancer-derived xenografts (PDX) that have high expression of PROCR. To the best our knowledge, this is the first comprehensive study of PROCR signaling in breast cancer cells, and its findings also shed light on the molecular mechanisms of PROCR in stem cells in normal tissue.

Topics: Cyclin D1; Endothelial Protein C Receptor; Female; Humans; MCF-7 Cells; Phosphatidylinositol 3-Kinases; Proto-Oncogene Proteins c-akt; Proto-Oncogene Proteins c-myc; Receptor, IGF Type 1; Signal Transduction; TOR Serine-Threonine Kinases; Triple Negative Breast Neoplasms

Autophagy is a catabolic process for degrading dysfunctional proteins and organelles, and closely associated with cancer cell survival under therapeutic, metabolic stress, hypoxia, starvation and lack of growth factors, contributing to resistance to therapies. However, the role of autophagy in breast cancer cells is not well understood. In the present study, we investigated the role of autophagy in highly aggressive and metastatic triple negative breast cancer (TNBC) and non-metastatic breast cancer cells and demonstrated that the knockdown of autophagy-related genes (LC3 and Beclin-1) inhibited autophagy and significantly suppressed cell proliferation, colony formation, migration/invasion and induced apoptosis in MDA-MB-231 and BT-549 TNBC cells. Knockdown of LC3 and Beclin-1 led to inhibition of multiple proto-oncogenic signaling pathways, including cyclin D1, uPAR/integrin-β1/Src, and PARP1. In conclusion, our study suggests that LC3 and Beclin-1 are required for cell proliferation, survival, migration and invasion, and may contribute to tumor growth and progression of highly aggressive and metastatic TNBC cells and therapeutic targeting of autophagy genes may be a potential therapeutic strategy for TNBC in breast cancer.

Topics: Autophagy; Beclin-1; Cell Line, Tumor; Cell Movement; Cell Proliferation; Cell Survival; Cyclin D1; Female; Gene Expression Regulation, Neoplastic; Humans; Integrin beta1; MCF-7 Cells; Microtubule-Associated Proteins; Molecular Targeted Therapy; Receptors, Urokinase Plasminogen Activator; RNA, Small Interfering; Signal Transduction; src-Family Kinases; Triple Negative Breast Neoplasms

The identification and targeting of key molecular drivers of melanoma and breast and lung cancer have substantially improved their therapy. However, subtypes of each of these three common, lethal solid tumors lack identified molecular drivers, and are thus not amenable to targeted therapies. Here we show that pleckstrin homology domain-interacting protein (PHIP) promotes the progression of these "driver-negative" tumors. Suppression of PHIP expression significantly inhibited both tumor cell proliferation and invasion, coordinately suppressing phosphorylated AKT, cyclin D1, and talin1 expression in all three tumor types. Furthermore, PHIP's targetable bromodomain is functional, as it specifically binds the histone modification H4K91ac. Analysis of TCGA profiling efforts revealed PHIP overexpression in triple-negative and basal-like breast cancer, as well as in the bronchioid subtype of nonsmall cell lung cancer. These results identify a role for PHIP in the progression of melanoma and breast and lung cancer subtypes lacking identified targeted therapies. The use of selective, anti-PHIP bromodomain inhibitors may thus yield a broad-based, molecularly targeted therapy against currently nontargetable tumors.

Topics: Animals; Breast; Carcinoma, Non-Small-Cell Lung; Cell Line, Tumor; Cell Proliferation; Cyclin D1; Female; Gene Expression Regulation, Neoplastic; Humans; Intracellular Signaling Peptides and Proteins; Lung Neoplasms; Melanoma; Pleckstrin Homology Domains; Proto-Oncogene Proteins c-akt; Triple Negative Breast Neoplasms

A sub-class of ER-negative breast cancer that is negative for ER, PR and HER2 expression known as triple-negative breast cancer (TNBC) is highly malignant and lacks effective treatment. Recently, it has been reported that an isoform of estrogen receptor-alpha ER-α36 is expressed and plays a critical role in development of TNBC. ER-α36 forms a positive regulatory loop with epidermal growth factor receptor (EGFR), which promotes malignant growth of TNBC cells. Thus, ER-α36 has been proposed as an important target for development of novel drugs for TNBC. In this study, we evaluated the effects of icaritin, a prenylflavonoid derivant purified from Epimedium Genus, on growth of TNBC cells and examined the possible underlying mechanisms. Our study demonstrated that icartin decreased both ER-α36 and EGFR protein expression, and induced apoptosis in TNBC MDA-MB-231 and MDA-MB-453 cells. We also found that icaritin inhibited ER-α36-mediated MAPK/ERK pathway and cyclin D1 induction by estrogen. Our results thus indicated that icaritin has a potential to be developed into a novel therapeutic agent for human TNBC.

Topics: Antineoplastic Agents, Phytogenic; Apoptosis; Cell Line, Tumor; Cell Proliferation; Cyclin D1; Epimedium; ErbB Receptors; Estrogen Antagonists; Estrogen Receptor alpha; Estrogens; Female; Flavonoids; Gene Expression Regulation, Neoplastic; Humans; MAP Kinase Signaling System; Neoplasm Proteins; Promoter Regions, Genetic; Recombinant Proteins; RNA Interference; Triple Negative Breast Neoplasms

Even with the identical clinicopathological features, the ability for metastasis is vastly different among triple-negative breast cancer (TNBC) patients. Intratumor heterogeneity (ITH), which is common in breast cancer, may be a key mechanism leading to the tumor progression. In this study, we studied whether a quantitative genetic definition of ITH can predict clinical outcomes in patients with TNBC. We quantified ITH by calculating Shannon index, a measure of diversity in a population, based on Myc, epidermal growth factor receptor/centromeric probe 7 (EGFR/CEP7) and cyclin D1/centromeric probe 11 (CCND1/CEP11) copy number variations (CNVs) in 300 cells at three different locations of a tumor. Among 75 TNBC patients, those who developed metastasis had significantly higher ITH, that is Shannon indices of EGFR/CEP7 and CCND1/CEP11 CNVs. Higher Shannon indices of EGFR/CEP7 and CCND1/CEP11 CNVs were significantly associated with the development of metastasis and were predictive of significantly worse metastasis-free survival (MFS). Regional heterogeneity, defined as the difference in copy numbers of Myc, EGFR or CCND1 at different locations, was found in 52 patients. However, the presence of regional heterogeneity did not correlate with metastasis or MFS. Our findings demonstrate that higher ITH of EGFR/CEP7 and CCND1/CEP11 CNVs is predictive of metastasis and is associated with significantly worse MFS in TNBC patients, suggesting that ITH is a very promising novel prognostic factor in TNBC.

Topics: Adult; Aged; Aged, 80 and over; Biomarkers, Tumor; Biopsy; Cohort Studies; Cyclin D1; Disease-Free Survival; ErbB Receptors; Female; Genetic Heterogeneity; Humans; Middle Aged; Neoplasm Metastasis; Neoplasm Staging; Neoplastic Stem Cells; Prognosis; Tissue Array Analysis; Triple Negative Breast Neoplasms

Triple-negative breast cancers (TNBCs) are neither susceptible to endocrine therapy due to a lack of estrogen receptor α expression nor trastuzumab. TNBCs frequently overexpress epidermal growth factor receptor (EGFR) and membrane bound estrogen receptor, GPER. To a certain extent the growth of TNBCs is stimulated by 17β-estradiol via GPER. We analyzed whether inhibition of EGFR by gefitinib reduces the expression of GPER and subsequent signal transduction in TNBC cells. Dependence of proliferation on 17β-estradiol was determined using Alamar Blue assay. Expression of GPR30 and activation of c-src, EGFR and cAMP-responsive element binding (CREB) protein by 17β-estradiol was analyzed by western blotting. Expression of c-fos, cyclin D1 and aromatase was determined using RT-PCR. Gefitinib reduced GPER expression concentration‑ and time‑dependently. In HCC70 cells, GPER expression was reduced to 15±11% (p<0.05) after treatment with 200 nM gefitinib for four days, and in HCC1806 cells GPER expression was reduced to 39±5% (p<0.01) of the control. 17β-estradiol significantly increased the percentage of HCC1806 cells within 7 days to 145±29% of the control (HCC70, 110±8%). This increase in cell growth was completely prevented in both TNBC cell lines after GPR30 expression was downregulated by treatment with 200 nM gefitinib. In HCC1806 cells, activation of c-src was increased by 17β-estradiol to 350±50% (p<0.01), and gefitinib reduced src activation to 110%. Similar results were obtained in the HCC70 cells. Phosphorylation of EGFR increased to 240±40% (p<0.05) in the HCC1806 cells treated with 17β-estradiol (HCC70, 147±25%). Gefitinib completely prevented this activation. Phosphorylation of CREB and induction of c-fos, cyclin D1 and aromatase expression by 17β-estradiol were all prevented by gefitinib. These experiments conclusively show that reduction of GPER expression is a promising therapeutic approach for TNBC.

Topics: Antineoplastic Agents; Aromatase; Cell Line, Tumor; Cell Proliferation; CSK Tyrosine-Protein Kinase; Cyclin D1; ErbB Receptors; Estradiol; Female; Gefitinib; Gene Expression Regulation, Neoplastic; Genes, fos; Humans; Phosphorylation; Quinazolines; Receptors, Estrogen; Receptors, G-Protein-Coupled; src-Family Kinases; Triple Negative Breast Neoplasms

Breast cancer is one of the most prevalent malignancies among women worldwide. Triple negative breast cancer (TNBC) is a type of breast cancer in which estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2 (HER-2) are not expressed. There is no targeted therapy for this type of cancer, and available therapies have poor therapeutic effects. Performing a preliminary research, we selected cyclin D1 (CCND1) gene of Wnt signaling pathway which is a target of miRNAs, a promising set of biomolecules in diagnosis and treatment of breast cancer. In this study using bioinformatic analyses, miR-17 was selected as it targets the 3'UTR of CCND1 gene with the highest score. Luciferase assay results also confirmed the bioinformatic prediction. Decreased expression of miR-17 in MDA-MB-231 cell line was observed using qRT-PCR method. After lentiviral transduction of miR-17 to the target cells, gene expression analysis showed decreased expression of CCND1 gene. We found miR-17 as an attractive molecule that after intensive research can probably be used as a biomarker in TNBC.

Topics: Computational Biology; Cyclin D1; Female; HEK293 Cells; Humans; In Vitro Techniques; MicroRNAs; RNA, Messenger; Triple Negative Breast Neoplasms

Triple negative breast cancer (TNBC) is an aggressive subtype of breast cancer with a poor prognosis, which lacks effective targeted therapies. There is an urgent need to better understand the underlying molecular mechanisms of TNBC aggressiveness and identify novel, efficient targets for therapeutic intervention.. miRNA qRT-PCR was used to determine the expression of miR-1296 in cell lines. The miR-1296 overexpression effects in TNBC cell lines were investigated using assays of colony formation, cell cycle and apoptosis. Immunoblotting was performed to determine the expression of the miR-1296 target protein, and luciferase assays were performed to confirm the target of miR-1296 action.. miR-1296 expression was significantly suppressed in TNBC cell lines and tissues samples. Overexpression of miR-1296 significantly suppressed cell proliferation of two TNBC cell lines when compared to control miRNA-expressing cells. A significant decrease in the S-phase of the cell cycle was observed following miR-1296 overexpression, accompanied by induction of apoptosis in TNBC cells. Cyclin D1 (CCND1) was identified as a target of miR-1296 action. miR-1296 overexpression significantly suppressed the luciferase activity of reporter plasmid containing the 3'UTR of CCND1 and protein expression levels of CCND1 in TNBC cells. The effects of miR-1296 overexpression on TNBC cell growth were reversed by CCND1 overexpression. miR-1296 expression sensitized TNBC cells to cisplatin treatment.. Our results demonstrate a novel tumor suppressor role for miR-1296 in triple-negative breast cancer cell lines, identify CCND1 as its target of action, and demonstrate a potential role for miR-1296 in sensitizing breast cancer cells to cisplatin.

Topics: 3' Untranslated Regions; Antineoplastic Agents; Apoptosis; Cell Cycle; Cell Line; Cell Line, Tumor; Cell Proliferation; Cisplatin; Cyclin D1; Gene Expression Regulation, Neoplastic; Genes, Tumor Suppressor; Humans; Immunoblotting; MicroRNAs; Reverse Transcriptase Polymerase Chain Reaction; Triple Negative Breast Neoplasms

Tissue inhibitor of metalloproteinases-1 (TIMP-1) is a multifunctional protein that can directly regulate apoptosis and metastasis. In this study, we investigated the functional and molecular mechanisms by which TIMP-1 influences triple-negative breast cancer (TNBC).. The expression level of TIMP-1 in breast cancer tissues was analyzed using the ONCOMINE microarray database. The overall survival of patients with distinct molecular subtypes of breast cancer stratified by TIMP-1 expression levels was evaluated using Kaplan-Meier analysis. Bisulfate sequencing PCR (BSP) was used to analyze the methylation status of the TIMP-1 promoter. Real-time-PCR (RT-PCR), Western blot and ELISA assays were used to evaluate gene and protein expression in cell lines and human tissue specimens. In addition, TIMP-1 function was analyzed using a series of in vitro and in vivo assays with cells in which TIMP-1 was inhibited using RNAi or neutralizing antibodies.. We found that serum TIMP-1 levels were strongly enhanced in patients with TNBC and that elevated TIMP-1 levels were associated with a poor prognosis in TNBC. However, TIMP-1 levels were not significantly associated with overall survival in other subtypes of breast cancer or in the overall population of breast cancer patients. We also report the first evidence that the TIMP-1 promoter is hypomethylated in TNBC cell lines compared with non-TNBC cell lines, suggesting that aberrant TIMP-1 expression in TNBC results from reduced DNA methylation. RNAi-mediated silencing of TIMP-1 in TNBC cells induced cell cycle arrest at the G1 phase and reduced cyclin D1 expression. In addition, mechanistic analyses revealed that the p-Akt and p-NF-κB signaling pathways, but not the GSK-3β and MAPK1/2 pathways, are associated with TIMP-1 overexpression in TNBC cells. Moreover, neutralizing antibodies against TIMP-1 significantly decreased the rate of tumor growth in vivo.. Our findings suggest that TIMP-1 is a biomarker indicative of a poor prognosis in TNBC patients and that targeting TIMP-1 may provide an attractive therapeutic intervention specifically for triple-negative breast cancer patients.

Topics: Animals; Antibodies, Monoclonal; Cell Cycle Checkpoints; Cell Line, Tumor; Cell Proliferation; Computational Biology; Cyclin D1; Databases, Genetic; Disease Models, Animal; DNA Methylation; Female; Gene Expression; Gene Expression Regulation, Neoplastic; Gene Silencing; Humans; Kaplan-Meier Estimate; Mice; Prognosis; Promoter Regions, Genetic; Proto-Oncogene Proteins c-akt; Signal Transduction; Tissue Inhibitor of Metalloproteinase-1; Triple Negative Breast Neoplasms; Tumor Burden; Xenograft Model Antitumor Assays

To study the inhibitory effect and mechanism of Ganoderma lipsiense extract (GLE) on the growth of triple-negative breast cancer (TNBC) cell line MDA-MB-231-HM in a mouse model.. The mouse model of TNBC was established by subcutaneous injection of 1.5 x 10(6) of MDA-MB-231-HM cells into BALB/c-nu mouse. Twenty successfully modeled mice were divided into the GLE group and the negative control group according to random digit table, 10 in each group. GLE (0.2 mL 100 mg/mL) was peritoneally injected to mice in the GLE group, while equal dose of normal saline was peritoneally injected to mice in the negative control group. The medication was administered once per 3 days and discontinued after 45 days. The CD34 expression was detected using immunohistochemical assay for counting microvessels. Meanwhile, expressions of thrombospondin 1 (TSP-1) and cyclin D1 were detected using immunohistochemical assay.. The average weight was obviously lower in the GLE group than in the negative control group [(0.33 ± 0.16) g vs (0.68 ± 0.37)g, P < 0.05]. The tumor inhibition rate was 51.4% in the GLE group. The volume of transplanted tumor was obviously lesser in the GLE group than in the negative control group (P < 0.05). Results of immunohistochemical staining showed, the microvessel density (MVD) under every field was (20.7 ± 2.1), TSP-1 positive cell count was (66.2 ± 9.2), cyclin D1 positive cell count was (33.8 ± 16.4) in the GLE group, and they were 34.0 ± 2.0, 24.0 ± 6.6, and 168.2 ± 32.6, respectively in the negative control group. There was statistical difference in all indices between the two groups (P < 0.05).. GLE could inhibit malignant proliferation of tumor cells by suppressing angiogenesis of blood vessels in tumor tissues and regulating cell cycles, thereby inhibiting TNBC.

Topics: Animals; Biological Products; Cell Line, Tumor; Cyclin D1; Disease Models, Animal; Ganoderma; Humans; Mice; Mice, Inbred BALB C; Mice, Nude; Microvessels; Neoplasm Transplantation; Neovascularization, Pathologic; Random Allocation; Thrombospondin 1; Triple Negative Breast Neoplasms

The tumor-suppressive let-7 family of microRNAs (miRNAs) has been previously identified to induce cell apoptosis, proliferation‑inhibition and suppression of the self‑renewal capacities of cancer stem cells (CSCs). However, let‑7‑mediated sensitization of tumors to radiation treatment remains to be investigated fully in triple negative breast cancer (TNBC), of which the clinical treatment is challenging. The inhibitory effect of let‑7 miRNAs on the self‑renewal ability of CSCs from TNBC was investigated. It was identified that radiation inhibited the self‑renewal ability of TNBC stem cells by inhibiting cyclin D1 and protein kinase B (Akt1) phosphorylation. Let‑7d stimulates radiation‑induced tumor repression, exerting synergistic effects with radiotherapy on stem cell renewal. Through western blotting, immunofluorescence and a luciferase assay, it was identified that reduced cyclin D1/Akt1/wingless type MMTV integration site family member 1 (Wnt1) signaling activity accounts for the let‑7‑induced radiation sensitization. Let‑7 directly inhibits cyclin D1 expression, resulting in low phosphorylation of Akt1, which is critical for the let‑7‑induced inhibition of mammosphere numbers. The let‑7d‑induced Akt1 inhibition contributed to tumor repression, with similar results to those obtained with Akt inhibitors. Furthermore, it was identified that the inhibition of Wnt1 is critical for the functioning of let‑7d, and that addition of recombinant Wnt1 abolished the effects of let‑7d on sensitization to radiotherapy. Let‑7d is suggested to be a promising therapeutic agent in the treatment of TNBC by targeting CSCs and sensitizing tumors to radiotherapy via inhibition of cyclin D1/Akt1/Wnt1 signaling.

Topics: Breast; Cell Line, Tumor; Cyclin D1; Female; Gene Expression Regulation, Neoplastic; Humans; MicroRNAs; Neoplastic Stem Cells; Proto-Oncogene Proteins c-akt; Signal Transduction; Triple Negative Breast Neoplasms; Wnt1 Protein

Several publications have suggested that histone deacetylase inhibitors (HDACis) could reverse the repression of estrogen receptor alpha (ERα) in triple-negative breast cancer (TNBC) cell lines, leading to the induction of a functional protein. Using different HDACis, vorinostat, panobinostat, and abexinostat, we therefore investigated this hypothesis in various human TNBC cell lines and patient-derived xenografts (PDXs). We used three human TNBC cell lines and three PDXs. We analyzed the in vitro toxicity of the compounds, their effects on the hormone receptors and hormone-related genes and protein expression both in vitro and in vivo models. We then explored intra-tumor histone H3 acetylation under abexinostat in xenograft models. Despite major cytotoxicity of all tested HDAC inhibitors and repression of deactylation-dependent CCND1 gene, neither ERα nor ERβ, ESR1 or ESR2 genes respectively, were re-expressed in vitro. In vivo, after administration of abexinostat for three consecutive days, we did not observe any induction of ESR1 or ESR1-related genes and ERα protein expression by RT-qPCR and immunohistochemical methods in PDXs. This observation was concomitant to the fact that in vivo administration of abexinostat increased intra-tumor histone H3 acetylation. These observations do not allow us to confirm previous studies which suggested that HDACis are able to convert ER-negative (ER-) tumors to ER-positive (ER+) tumors, and that a combination of HDAC inhibitors and hormone therapy could be proposed in the management of TNBC patients.

Topics: Benzofurans; Cell Proliferation; Cyclin D1; Estrogen Receptor alpha; Estrogen Receptor beta; Female; Gene Expression Regulation, Neoplastic; Histone Deacetylase Inhibitors; Histones; Humans; Hydroxamic Acids; Indoles; Panobinostat; Receptor, ErbB-2; Triple Negative Breast Neoplasms; Vorinostat; Xenograft Model Antitumor Assays

Breast cancer is considered the most common cancer for women worldwide and it is now the second leading cause of cancer-related deaths among females in the world. Since breast cancer is highly resistant to chemotherapy, alternative anticancer strategies have been developed. In particular, many studies have demonstrated that curcumin, a derivative of turmeric, can be used as natural agent in treatment of some types of cancer by playing antiproliferative and antioxidant effects. In our study, we assessed the antitumor activities of curcumin in ER-negative human breast cancer cell line resistant to chemotherapy, MDA.MB231 by in vitro and in vivo experiments. In vitro data allowed us to demonstrate that curcumin played a role in regulation of proliferation and apoptosis in MDA.MB231 cells. In vivo, by generation of mouse model of breast cancer, we showed that treatment of curcumin inhibited tumor growth and angiogenesis. Specifically, we showed that curcumin is able to deregulate the expression of cyclin D1, PECAM-1, and p65, which are regulated by NF-κB. Our data demonstrated that curcumin could be used as an adjuvant agent to chemotherapy in treatment of triple negative breast cancer.

Topics: Animals; Apoptosis; Breast Neoplasms; Cell Proliferation; Curcumin; Cyclin D1; Drug Resistance, Neoplasm; Female; Gene Expression Regulation, Neoplastic; Humans; Mice; Neovascularization, Pathologic; NF-kappa B; Triple Negative Breast Neoplasms; Xenograft Model Antitumor Assays

CD99 is a protein initially described in the Ewing sarcoma family of tumors, but growing evidence has shown its expression in other tumors of mesenchymal, hematopoietic and even epithelial origin. Some articles report CD99 in metaplastic carcinoma of the breast, a subtype of breast carcinoma (BC) with pronounced epithelial to mesenchymal (EMT) phenotype. Our aim was to analyse the potential relationship between CD99 and selected EMT (vimentin, E-cadherin, Twist) and proliferation markers (Ki-67, c-myc, cyclin D1, topoisomerase 2), molecular subtypes of BC, as well as overall survival (OS) and progression-free survival (PFS). In a group of 122 cases CD99 membrane expression was seen in 14 (11.5%) cases: strong in 11 (9%) and moderate in 3 (2.5%). Expression of CD99 correlated with low cyclin D1 index, high level of topoisomerase 2 expression and lack of progesterone receptor (PR) but not with EMT characteristics. Additionally, strong expression of CD99 correlated with triple negative molecular BC phenotype. CD99 was prognostically irrelevant for OS and PFS. CD99 correlates with selected proliferative markers and low ER/PR receptor status but not with patients' outcome in BC. Further studies are required to explain precisely its role in molecular pathogenesis of BC.

Topics: 12E7 Antigen; Adult; Antigens, CD; Antigens, Neoplasm; Biomarkers, Tumor; Breast Neoplasms; Cell Adhesion Molecules; Cyclin D1; Disease-Free Survival; DNA Topoisomerases, Type II; DNA-Binding Proteins; Epithelial-Mesenchymal Transition; Female; Humans; Immunohistochemistry; Kaplan-Meier Estimate; Middle Aged; Phenotype; Prognosis; Tissue Array Analysis; Triple Negative Breast Neoplasms

S-phase kinase-associated protein 2 (SKP2) is an important cell cycle regulator, targeting the cyclin-dependent kinase (CDK) inhibitor p27 for degradation, and is frequently overexpressed in breast cancer. p27 regulates G1 /S transition by abrogating the activity of cyclin/CDK complexes. p27 can undergo phosphorylation at serine 10 (pSer10p27). This phosphorylation event is associated with increased cell proliferation and poor prognosis in patients with glioma. The relationship between SKP2 and pSer10p27 in breast cancer has not been previously investigated. Immunohistochemistry (IHC) of SKP2, p27, pSer10p27, and other genes involved in this pathway, was analyzed in 188 breast tumors and 50 benign reduction mammoplasty samples. IHC showed SKP2 to be more highly expressed in estrogen receptor α (ERα)-negative breast cancers and demonstrated that triple-negative tumors were more likely to have high expression of SKP2 than were non-triple negative, ERα-negative tumors. A significant positive relationship was discovered for SKP2 and pSer10p27. High levels of SKP2 and pSer10p27 were observed significantly more often in ERα-negative and triple-negative than in ERα-positive breast cancers. Use of the triple-negative TMX2-28 breast cancer cell line to address the role of SKP2 in cell cycle progression confirmed that SKP2 contributes to a more rapid cell cycle progression and may regulates pSer10p27 levels. Together, the results indicate that presence of high SKP2 plus high pSer10p27 levels in triple-negative breast cancers is associated with aggressive growth, and highlight the validity of using SKP2 inhibitors as a therapeutic approach for treating this subset of breast cancers.

Topics: Adult; Age Factors; Aged; Aged, 80 and over; Biomarkers, Tumor; Cell Cycle; Cell Proliferation; Cyclin D1; Cyclin-Dependent Kinase 2; Cyclin-Dependent Kinase Inhibitor p27; Estrogen Receptor alpha; Female; Gene Expression Regulation, Neoplastic; Humans; MCF-7 Cells; Middle Aged; Neoplasm Grading; Neoplasm Invasiveness; Phosphorylation; RNA Interference; S-Phase Kinase-Associated Proteins; Serine; Signal Transduction; Transfection; Triple Negative Breast Neoplasms; Up-Regulation

Due to the lack of ERα, triple negative breast cancers (TNBCs) are not susceptible to endocrine therapy using antiestrogens. However, the majority of TNBCs express the membrane bound estrogen receptor GPR30. We have recently shown that knock-down of GPR30 expression prevented growth stimulation of TNBC cell lines by 17β-estradiol. Now we analyzed whether specific inhibition of GPR30 represents a new option for therapy of TNBC.. Growth of TNBC cells was assessed using Alamar-blue colorimetric assay. Activation of c-Src and EGF-receptor was assessed using Western blots. Expression of c-fos, cyclin D1 and aromatase was quantified by RT-PCR. Gα-specific signaling of GPR30 was analyzed by electrophoretic mobility shift assay.. HCC1806 cells showed the highest GPR30 expression, in HCC70 cells it was clearly lower, in MDA-MB-231 cells it was lowest. 10-8 M 17β-estradiol significantly increased proliferation of HCC1806 cells to 134 ± 12% of control (p < 0.01). Proliferation of HCC70 cells was slightly increased to 116 ± 8% of control. Estriol significantly reduced cell number of HCC1806 cells to 16 ± 12% (p < 0.01). Cell number of HCC70 cells and of MDA-MB-231 cells was reduced to 68 ± 25% and to 61 ± 10%, respectively.Activity of Src kinase increased to 150 ± 10% (p < 0.05) by 10-8 M 17β-estradiol treatment in HCC1806 and to 220 ± 20% in HCC70 cells (p < 0.01). Estriol treatment completely inhibited 17β-estradiol-induced p-src activation. Transactivation of EGF-receptor increased by estradiol treatment to 350% in HCC1806 and to 280% in HCC70 cells. Estriol completely suppressed EGF-receptor transactivation. c-fos expression increased to 260% and to 190%, respectively. Estriol reduced this induction to 160% (HCC1806) and below control in HCC70 cells. Cyclin D1 was induced to 290% (HCC1806) and 170% (HCC70) and completely inhibited by estriol. 17β-estradiol increased CREB-phosphorylation to 400%. Binding of phospho-CREB to a CRE of cyclin D1 was enhanced to 320%.. Specific pharmacological inhibition of GPR30 might become a promising targeted therapy for TNBC in future.

Topics: Cell Line, Tumor; Cell Proliferation; Cyclic AMP Response Element-Binding Protein; Cyclin D1; Estradiol; Estriol; Estrogens; Gene Expression Regulation, Neoplastic; Humans; Phosphorylation; Receptors, Estrogen; Receptors, G-Protein-Coupled; Triple Negative Breast Neoplasms

Receptor for Advanced Glycation End Products (RAGE) is an oncogenic trans-membranous receptor overexpressed in various human cancers. However, the role of RAGE in breast cancer development and proliferation is still unclear. In this study, we demonstrated that RAGE expression levels are correlated to the degree of severity of breast cancer. Furthermore, there is a decrease in the proliferation of all sub-types of breast cancer, MCF-7, SK-Br-3 and MDA-MB-231, as a result of the effect of RAGE siRNA. RAGE siRNA arrested cells in the G1 phase and inhibited DNA synthesis (p < 0.05). Moreover, qRT-PCR and Western Blot results demonstrated that RAGE siRNA decreases the expression of transcriptional factor NF-κB p65 as well as the expression of cell proliferation markers PCNA and cyclinD1. RAGE and RAGE ligands can thus be considered as possible targets for breast cancer management and therapy.

Topics: Apoptosis; Breast Neoplasms; Cell Line, Tumor; Cell Proliferation; Cell Survival; Cyclin D1; DNA, Neoplasm; Female; G1 Phase Cell Cycle Checkpoints; Gene Expression; Gene Knockdown Techniques; Humans; MCF-7 Cells; Proliferating Cell Nuclear Antigen; Receptor for Advanced Glycation End Products; Receptors, Immunologic; RNA, Messenger; RNA, Neoplasm; RNA, Small Interfering; Transcription Factor RelA; Triple Negative Breast Neoplasms

Deregulation of the cell cycle machinery is often found in human cancers. Modulations in the cell cycle regulator function and expression result not only in proliferative advantages, but also lead to tumor progression and invasiveness of the cancer. In particular, cyclin D1 and p21 are often over-expressed in human cancers, correlating with high tumor grade, poor prognosis and increased metastasis. This prompted us to investigate the role of the cyclin D1/p21 signaling axis downstream of transforming growth factor beta (TGFβ) in breast cancer progression.. Cyclins mRNA and protein expressions were assessed by quantitative real-time PCR and Western blot in triple negative breast cancer cell lines. Co-localization and interaction between cyclin D1 and p21 were performed by immunocytochemistry and co-immunoprecipitation, respectively. Cell migration was assessed by wound healing and quantitative time-lapse imaging assays. In addition, the effects of cyclin D1 on cellular structure and actin organization were examined by staining with F-actin marker phalloidin and mesenchymal intermediate filament vimentin. Finally, a mammary fat pad xenograft mouse model was used to assess mammary tumor growth and local invasion.. We found TGFβ to specifically up-regulate the expression of cyclin D1 in triple negative breast cancer cells. Induction of cyclin D1 is also required for TGFβ-mediated cell migration. Suppression of cyclin D1 expression not only resulted in a rounded and epithelial-like phenotype, but also prevented TGFβ-induced vimentin and F-actin co-localization at the cell edge as well as invadopodia formation. Furthermore, TGFβ promoted the nuclear co-localization and physical interaction between cyclin D1 and p21. The co-expression of cyclin D1 and p21 proteins are required for the initial steps of tumor development, as double knockdown of these two molecules prevented primary tumor formation in a Xenograft mouse model. Moreover, the in vivo studies indicated that locally advanced features of the invasive tumors, including skeletal muscle, mammary fat pad and lymphovascular invasion, as well as ulcerated skin, were attenuated in the absence of cyclin D1 and p21.. Thus, our findings highlight the cyclin D1/p21 signaling axis as a critical regulator of TGFβ-mediated tumor growth initiation and local tumor cell invasion, both in vitro and in vivo.

Topics: Animals; Cell Cycle Checkpoints; Cell Line, Tumor; Cell Movement; Cyclin D1; Cyclin-Dependent Kinase Inhibitor p21; Female; Gene Expression Regulation, Neoplastic; Humans; Mice; Neoplasm Invasiveness; Signal Transduction; Transforming Growth Factor beta; Triple Negative Breast Neoplasms; Xenograft Model Antitumor Assays