Growth Of Human Breast Cancer Cells Research Articles

Abstract PO3-24-02: Molecular characterization and therapeutic approach for VISTA+ triple-negative breast cancers

Abstract Introduction: Current FDA-approved immunotherapeutics for triple-negative breast cancer are only available for a subset of patients, highlighting the need to develop improved immune-targeting strategies. VISTA (V-domain Ig suppressor of T cell activation) is a single-pass transmembrane immune checkpoint receptor that is an emerging clinical target for cancer immunotherapy. It is expressed widely on lymphoid and myeloid cells in healthy individuals, is commonly expressed on cells of the tumor microenvironment and can be abnormally upregulated on tumor cells in a wide variety of tumors. Although VISTA confers quiescence to naïve T cells, molecular mechanisms responsible for this effect remain unclear. Also, the effects of VISTA expression on tumor cells remains poorly defined. Methods: Multi-omic profiling was performed in human breast cancer cells lines to determine immune regulatory genes controlled by growth factor stimulation. Human triple-negative breast cancer tumor specimens (N=248) were examined by immunohistochemistry for expression of VISTA, PDL1, PD1 and FoxP3. VISTA expression was engineered into human and mouse triple-negative breast cancer cell lines and growth metrics were characterized in vitro and in immunocompetent (syngeneic) and immunodeficient (xenograft) mouse tumor models. Membrane receptor trafficking and localization of EGFR was performed in human TNBC cells lines expressing VISTA and VISTA mutants. Proximity biotinylation identified protein partners that interacted with VISTA’s intracellular domain. Deletion mutagenesis was performed to identify motifs required for biochemical interactions between VISTA and clathrin adaptor proteins. Clathrin adapter localization was examined in WT and VISTA knock-out cell lines. Cytokine response, clathrin adaptor localization and tumor growth kinetics were measured in TNBC cell lines expressing VISTA or VISTA mutants. Results: A class of human triple-negative breast cancers were identified with high VISTA expression, low tumor infiltrating lymphocytes and low proliferative index (8-20% of all TNBCs). Tumor models demonstrated that enforced expression of VISTA in tumor cells caused growth suppression, even in the absence of an immune system. This effect was mapped to the cytoplasmic domain of VISTA, which lacks defined signaling domains. Through biochemical approaches, the clathrin-adaptor molecules NUMB and GULP1 were found in complex with a VISTA intracellular NPGF motif. This motif sequestered NUMB at early endosomes, resulting in diminished NUMB recycling for EGFR endocytosis, thereby causing growth suppression. VISTA impaired NUMB recycling by blocking Rab11 effector complex formation. VISTA NPGF mutations did not disrupt cytokine secretion in mixed lymphocyte assays. VISTA-targeted antibodies did not disrupt NUMB sequestration. VISTA+ tumors were selectively sensitive to VISTA-blocking antibodies. Conclusions: VISTA+ TNBC have distinct features including slower proliferative index and increased sensitivity to VISTA-blocking antibodies. This work identifies mechanisms by which VISTA enforces a quiescent cellular state by sequestering clathrin adapter proteins away from sites of endocytosis in cancer cells. This is the first description of intracellular molecular mechanisms controlled by VISTA’s intracellular tail. It may inform features of the VISTA-dependent immune checkpoint that could be exploited to improve anti-tumor immunity. Citation Format: Yan Zhao, Fatima Charles, Andrew Lipchik, Yan Peng, James Ford, Melinda Telli, Song Zhang, Allison Kurian, Michael Snyder, Joshua Gruber. Molecular characterization and therapeutic approach for VISTA+ triple-negative breast cancers [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO3-24-02.

Abstract B027: Molecular characterization and therapeutic approaches for VISTA+ triple-negative breast cancers

Abstract Introduction: VISTA (V-domain Ig suppressor of T cell activation) is a single-pass transmembrane immune checkpoint receptor that is an emerging clinical target for cancer immunotherapy. Although VISTA confers quiescence to naïve T cells, molecular mechanisms responsible for this effect remain unclear. Also, the effects of VISTA expression on tumor cells remains poorly defined. Methods: Multi-omic profiling was performed in human breast cancer cells lines to determine immune regulatory genes. Human triple-negative breast cancers (N=248) were examined by immunohistochemistry for expression of VISTA, PDL1, PD1 and FoxP3. VISTA expression was engineered into human and mouse triple-negative breast cancer cell lines and growth was characterized in vitro and in mouse models. Membrane receptor trafficking and localization of EGFR and clathrin adapters was performed in cells expressing VISTA, VISTA mutants and VISTA knockouts. Proximity biotinylation identified protein partners that interacted with VISTA’s intracellular domain. Deletion mutagenesis was performed to identify functional VISTA cytoplasmic motifs. Cytokine response and tumor growth kinetics were measured in TNBC mouse models expressing VISTA or VISTA mutants. Results: A class of human triple-negative breast cancers were identified with high VISTA expression, low tumor infiltrating lymphocytes and low proliferative index (8-20% of all TNBCs). Tumor models demonstrated that enforced expression of VISTA in tumor cells caused growth suppression, even in the absence of an immune system. This effect was mapped to the cytoplasmic domain of VISTA, which lacks defined signaling domains. Through biochemical approaches, the clathrin-adaptor molecules NUMB and GULP1 were found in complex with a VISTA intracellular NPGF motif. This motif sequestered NUMB at early endosomes, resulting in diminished NUMB recycling for EGFR endocytosis, thereby causing growth suppression. VISTA impaired NUMB recycling by blocking Rab11 effector complex formation. VISTA NPGF mutations did not disrupt cytokine secretion in mixed lymphocyte assays. VISTA-targeted antibodies did not disrupt NUMB sequestration. VISTA+ tumors were selectively sensitive to VISTA-blocking antibodies. Conclusions: VISTA+ TNBC have distinct features including slower proliferative index and increased sensitivity to VISTA-blocking antibodies. This work identifies mechanisms by which VISTA enforces a quiescent cellular state by sequestering clathrin adapter proteins away from sites of endocytosis in cancer cells. This is the first description of intracellular molecular mechanisms controlled by VISTA’s intracellular tail. It may inform features of the VISTA-dependent immune checkpoint that could be exploited to improve anti-tumor immunity. Integration of these findings with ongoing VISTA clinical trials will be discussed. Citation Format: Joshua Gruber, Yan Zhao, Fatima Charles, Priyanka Reddy, Kristina Paul, Virginia Ezenwa, Marisa Juntilla, Idit Sagiv-Barfi, Yan Peng, Song Zhang, Allison Kurian, Michael Snyder. Molecular characterization and therapeutic approaches for VISTA+ triple-negative breast cancers [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Breast Cancer Research; 2023 Oct 19-22; San Diego, California. Philadelphia (PA): AACR; Cancer Res 2024;84(3 Suppl_1):Abstract nr B027.

UPR-Induced miR-616 Inhibits Human Breast Cancer Cell Growth and Migration by Targeting c-MYC.

C/EBP homologous protein (CHOP), also known as growth arrest and DNA damage-inducible protein 153 (GADD153), belongs to the CCAAT/enhancer-binding protein (C/EBP) family. CHOP expression is induced by unfolded protein response (UPR), and sustained CHOP activation acts as a pivotal trigger for ER stress-induced apoptosis. MicroRNA-616 is located within an intron of the CHOP gene. However, the regulation of miR-616 expression during UPR and its function in breast cancer is not clearly understood. Here we show that the expression of miR-616 and CHOP (host gene of miR-616) is downregulated in human breast cancer. Both miR-5p/-3p arms of miR-616 are expressed with levels of the 5p arm higher than the 3p arm. During conditions of ER stress, the expression of miR-616-5p and miR-616-3p arms was concordantly increased primarily through the PERK pathway. Our results show that ectopic expression of miR-616 significantly suppressed cell proliferation and colony formation, whereas knockout of miR-616 increased it. We found that miR-616 represses c-MYC expression via binding sites located in its protein coding region. Furthermore, we show that miR-616 exerted growth inhibitory effects on cells by suppressing c-MYC expression. Our results establish a new role for the CHOP locus by providing evidence that miR-616 can inhibit cell proliferation by targeting c-MYC. In summary, our results suggest a dual function for the CHOP locus, where CHOP protein and miR-616 can cooperate to inhibit cancer progression.

RNA interference screens discover proteases as synthetic lethal partners of PI3K inhibition in breast cancer cells.

Rationale: PI3K/mTOR signaling is frequently upregulated in breast cancer making inhibitors of this pathway highly promising anticancer drugs. However, PI3K-inhibitors have a low therapeutic index. Therefore, finding novel combinatory treatment options represents an important step towards clinical implementation of PI3K pathway inhibition in breast cancer therapy. Here, we propose proteases as potential synergistic partners with simultaneous PI3K inhibition in breast cancer cells.Methods: We performed mRNA expression studies and unbiased functional genetic synthetic lethality screens by a miR-E based knockdown system targeting all genome-encoded proteases, i.e. the degradome of breast cancer cells. Importantly theses RNA interference screens were done in combination with two PI3K pathway inhibitors. Protease hits were validated in human and murine breast cancer cell lines as well as in non-cancerous cells by viability and growth assays.Results: The degradome-wide genetic screens identified 181 proteases that influenced susceptibility of murine breast cancer cells to low dose PI3K inhibition. Employing independently generated inducible knockdown cell lines we validated 12 protease hits in breast cancer cells. In line with the known tumor promoting function of these proteases we demonstrated Usp7 and Metap2 to be important for murine and human breast cancer cell growth and discovered a role for Metap1 in this context. Most importantly, we demonstrated that Usp7, Metap1 or Metap2 knockdown combined with simultaneous PI3K inhibition resulted in synergistic impairment of murine and human breast cancer cell growthConclusion: We successfully established proteases as combinatory targets with PI3K inhibition in human and murine breast cancer cells. Usp7, Metap1 and Metap2 are synthetic lethal partners of simultaneous protease/PI3K inhibition, which may refine future breast cancer therapy.

Abstract 2573: The anticancer effects of the vitamin E isoform, γ-tocotrienol, and vitamin D3 act synergistically to inhibit MDA-MB-231 triple negative breast cancer (TNBC) cell proliferation and viability in vitro

Abstract Epidemiological studies suggest that dietary intake of some natural products may be effective in reducing the risk of breast cancer. Furthermore, various phytochemicals have been shown to interfere with cell signaling pathways involved in regulating breast cancer cell proliferation and viability. γ-Tocotrienol is a natural isoform of vitamin E that displays potent anticancer activity against a variety of cancer cell types at treatment doses that have little or no effect on normal cell growth or viability. Vitamin D3 is an abundant phytochemical which also displays potent antiproliferative and antiangiogenic activity against human breast cancer cells. Studies were conducted to examine the effects of γ-tocotrienol and vitamin D3 given alone or in combination on MDA-MB-231 triple negative breast cancer (TNBC) cellular proliferation, migration, colony formation, invasion, cell cycle progression, and apoptosis. Results showed that combined treatment with subeffective doses of γ-tocotrienol (8 μM) and vitamin D3 (10 nM) synergistically inhibited the growth of MDA-MB-231 cells, as determined by the MTT assay and isobologram analysis. Additional studies indicated that this combination treatment resulted in a significant inhibition in cancer cell migration and a significant reduction in cancer cell colony formation. Studies using the Matrigel invasion assay showed that combined treatment with subeffective doses of γ-tocotrienol and vitamin D3, significantly inhibited MDA-MB-231 invasiveness. Flow cytometry analysis showed that similar combined treatment of γ-tocotrienol and vitamin D3 significantly increased the percentage of cells found in G0/G1 phase, as compared to cells in the vehicle-treated control group. After 4 days of combined treatment with subeffective doses of γ-tocotrienol and vitamin D3, the percentage of cells in the G0/G1 phase of the cell cycle increased to 55% (p<0.05, all p values compared to untreated cells), as compared to 37.48% for cells in the vehicle-treated control group. In addition, combination treatment with subeffective doses of γ-tocotrienol and vitamin D3, significantly increased the number of apoptotic and necrotic cells, as comparted to cells in the vehicle-treated control group. In summary, these findings indicate that combined treatment with subeffective doses of γ-tocotrienol and vitamin D3 act synergistically to inhibit MDA-MB-231 human breast cancer cell growth and viability, and strongly suggest that combined treatment with these agents may provide some benefits in the treatment of TNBC in women. This study was supported in part by funding from the Louisiana Cancer Foundation. Citation Format: Md. R. Anwar, A.K.M.N. Hossian, Georgios Matthaiolampakis, Paul W. Sylvester. The anticancer effects of the vitamin E isoform, γ-tocotrienol, and vitamin D3 act synergistically to inhibit MDA-MB-231 triple negative breast cancer (TNBC) cell proliferation and viability in vitro [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2573.

Hierarchical drug release designed Au @PDA-PEG-MTX NPs for targeted delivery to breast cancer with combined photothermal-chemotherapy

Breast cancer (BC) is the most frequently diagnosed cancer with a low survival rate and one of the major causes of cancer-related death. Methotrexate (MTX) is an anti-tumor drug used in the treatment of BC. Poor dispersion in water and toxic side effects limit its clinical application. Gold nanoparticles (AuNPs), owing to their specific structures and unique biological and physiochemical properties, have emerged as potential vehicles for tumor targeting, bioimaging and cancer therapy. An innovative nano drug-loading system (Au @PDA-PEG-MTX NPs) was prepared for targeted treatment of BC. Au @PDA-PEG-MTX NPs under near infra-red region (NIR) irradiation showed effective photothermal therapy against MDA-MB-231 human BC cells growth in vitro by inducing apoptosis through triggering reactive oxygen species (ROS) overproduction and generating excessive heat. In vivo studies revealed deep penetration ability of Au @PDA-PEG-MTX NPs under NIR irradiation to find application in cancer-targeted fluorescence imaging, and exhibited effective photothermal therapy against BC xenograft growth by inducing apoptosis. Histopathological analysis, cellular uptake, cytotoxicity assay, and apoptosis experiments indicated that Au @PDA-PEG-MTX NPs possessed a good therapeutic effect with high biocompatibility and fewer side effects. This Au NPs drug-loading system achieved specific targeting of MTX to BC cells by surface functionalisation, fluorescence imaging under laser irradiation, combined photothermal-chemotherapy, and pH- and NIR- triggered hierarchical drug release.

SIRT6 enhances oxidative phosphorylation in breast cancer and promotes mammary tumorigenesis in mice

BackgroundSirtuin 6 (SIRT6) is a NAD+-dependent deacetylase with key roles in cell metabolism. High SIRT6 expression is associated with adverse prognosis in breast cancer (BC) patients. However, the mechanisms through which SIRT6 exerts its pro-oncogenic effects in BC remain unclear. Here, we sought to define the role of SIRT6 in BC cell metabolism and in mouse polyoma middle T antigen (PyMT)-driven mammary tumors.MethodsWe evaluated the effect of a heterozygous deletion of Sirt6 on tumor latency and survival of mouse mammary tumor virus (MMTV)-PyMT mice. The effect of SIRT6 silencing on human BC cell growth was assessed in MDA-MB-231 xenografts. We also analyzed the effect of Sirt6 heterozygous deletion, of SIRT6 silencing, and of the overexpression of either wild-type (WT) or catalytically inactive (H133Y) SIRT6 on BC cell pyruvate dehydrogenase (PDH) expression and activity and oxidative phosphorylation (OXPHOS), including respiratory complex activity, ATP/AMP ratio, AMPK activation, and intracellular calcium concentration.ResultsThe heterozygous Sirt6 deletion extended tumor latency and mouse survival in the MMTV-PyMT mouse BC model, while SIRT6 silencing slowed the growth of MDA-MB-231 BC cell xenografts. WT, but not catalytically inactive, SIRT6 enhanced PDH expression and activity, OXPHOS, and ATP/AMP ratio in MDA-MB-231 and MCF7 BC cells. Opposite effects were obtained by SIRT6 silencing, which also blunted the expression of genes encoding for respiratory chain proteins, such as UQCRFS1, COX5B, NDUFB8, and UQCRC2, and increased AMPK activation in BC cells. In addition, SIRT6 overexpression increased, while SIRT6 silencing reduced, intracellular calcium concentration in MDA-MB-231 cells. Consistent with these findings, the heterozygous Sirt6 deletion reduced the expression of OXPHOS-related genes, the activity of respiratory complexes, and the ATP/AMP ratio in tumors isolated from MMTV-PyMT mice.ConclusionsVia its enzymatic activity, SIRT6 enhances PDH expression and activity, OXPHOS, ATP/AMP ratio, and intracellular calcium concentration, while reducing AMPK activation, in BC cells. Thus, overall, SIRT6 inhibition appears as a viable strategy for preventing or treating BC.

A study of the biological activity of 4-(Para-Substituted phenyl)-1,2,3-Selenadiazole derivatives as anti-oxidant and anti-breast cancer

In present work, five ligands of substituted 1,2,3-selenadiazole have been synthesized and characterized and they tested as possible anti-oxidant and anti-breast cancer. The synthesized compounds were prepared by the reaction of selenium dioxide with a series of semicabazone derivatives in glacial acetic acid. The prepared compounds have been characterized using different methods. The biological activity of 1,2,3-selenadiazole compounds were examined against the growth of two types of bacterial strains (E.coli and staphylococcus aureus). Also this study included determined the activity of 1,2,3-selenadiazole derivatives as antioxidants, and measured their ability toward α, α-diphenyl-β-picrylhydrazyl (DPPH) free radical scavenging. It has been found that they have a good activity to reduce free radical’s effects. Inhibition of 1,2,3-selenadiazole derivatives was carried out against human breast cancer cells (MCF-7) growth by MTT , the measurements showed that the derivatives had a higher inhibition rate than the complexes , the IC50 of compounds D3 and D4 was ( 89.5 and 44.3) µg/ ml respectively

Lutein inhibits breast cancer cell growth by suppressing antioxidant and cell survival signals and induces apoptosis.

Reduced risk of breast cancer upon intake of lutein-rich food supplements creates an interest to investigate the molecular mechanism underlying the growth inhibitory potential of lutein in MCF-7 and MDA-MB-231 cells. Lutein purified from Spinacia oleracea was identified by high-performance liquid chromatography and liquid chromatography-mass spectrometry. The cell viability was measured by water-soluble tetrazolium-1 assay. The intracellular reactive oxygen species level was examined by 2',7'-dichlorofluorescein assay. The protein expression of the markers of antioxidant defense, cell survival, and apoptosis was analyzed by western blot analysis. The induction of apoptosis by lutein was measured by 4',6-diamidino-2-phenylindole staining and caspase-3 activity assay. The purified lutein inhibited the viability of MCF-7 and MDA-MB-231 cells. The growth inhibitory effect of lutein was associated with suppressed protein expression of superoxide dismutase-2 and heme oxygenase-1, and its transcription factor nuclear factor erythroid 2-related factor-2. Lutein treatment subsequently blocked the expression of intracellular cell survival proteins, phosphorylated protein kinase B, phosphorylated extracellular-regulated kinase 1/2, and nuclear factor-kB. Suppression of antioxidant defense and cell survival markers by lutein was further linked to apoptosis induction with elevated caspase-3 activity and downregulated expression of Bcl-2 and poly-ADP ribose polymerase. Our results emphasize a significant role of lutein as an effective inhibitor of human breast cancer cell growth that activates cell death partly through the modulation of antioxidant defense response-linked cell survival signaling markers.

Anticancer Potential of Aguerin B, a Sesquiterpene Lactone Isolated from Centaurea behen in Metastatic Breast Cancer Cells.

Breast carcinoma is a malignant disease that represents the most common non-skin malignancy and a chief reason of cancer death in women. Large interest is growing in the use of natural products for cancer treatment, especially with goal of suppression angiogenesis, tumor cell growth, motility, as well as invasion and metastasis with low/no toxicity. It is evident from recent patents on the anticancer properties of sesquiterpene lactones such as parthenolide. In this study, using MDA-MB-231 cells of a human breast adenocarcinoma, the effects of aguerin B, as a natural sesquiterpene lactone, has been evaluated, in terms of the expression of metastatic-related genes (Pak-1, Rac-1 and HIF-1α). Cytotoxicity of aguerin B was tested toward MDA-MB-231 breast tumor cells using MTT. Scratch assay was accomplished to evaluate the tumor cell invasion. To understand the underlying molecular basis, the mRNA expressions were evaluated by real time PCR. It was found that aguerin B significantly inhibited human breast cancer cell growth in vitro (IC50 = 2μg/mL) and this effect was accompanied with a persuasive suppression on metastasis. Our results showed that aguerin B in IC50 concentration down-regulated Rac-1, Pak-1, Hif-1α and Zeb-1 transcriptional levels. Taken together, this study demonstrated that aguerin B possessed potential anti-metastatic effect, suggesting that it may consider as a potential multi target bio compound for treatment of breast metastatic carcinoma.

Potential Metabolite Nymphayol Isolated from Water Lily (Nymphaea stellata) Flower Inhibits MCF-7 Human Breast Cancer Cell Growth via Upregulation of Cdkn2a, pRb2, p53 and Downregulation of PCNA mRNA Expressions.

Controlled production of cyclin dependent kinases (CDK) and stabilization of tumor suppressor genes are the most important factors involved in preventing carcinogenesis. The present study aimed to explore the cyclin dependent apoptotic effect of nymphayol on breast cancer MCF-7 cells. In our previous study, we isolated the crystal from a chloroform extract of Nymphaea stellata flower petals and it was confirmed as nymphayol (17-(hexan-2-yl)-10,13-dimethylhexadecahydro-1H-cyclopenta[a]phenanthren-3-ol) using x-ray diffraction (XRD), Fourier transform infrared (FTIR), and mass spectroscopy (MS) methods. The cytotoxic effect of nymphayol on MCF-7 cells were analyzed using the 3-(4,5-dimethylthiazol-2yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. The cellular and nuclear damage was determined using propidium iodide (PI) and acridine orange/ethidium bromide (AO/ErBr) staining. Tumor suppressor and apoptosis related mRNA transcript levels were determined using real-time polymerase chain reaction (RT-PCR). Nymphayol potentially inhibits MCF-7 cell viability up to 78%, and the IC50 value was observed as 2.8 µM in 24 h and 1.4 µM in 48 h. Treatment with nymphayol significantly increased reactive oxygen species (ROS) level and the tunnel assay confirmed DNA damage. We found characteristically 76% apoptotic cells and 9% necrotic cells in PI and AO/ErBr staining after 48 h treatment with 2.8 µM of nymphayol. Gene expression analysis confirmed significantly (p ≤ 0.001) increased mRNA levels of cyclin dependent kinase inhibitor 2A (Cdkn2a), retinoblastoma protein 2 (pRb2), p53, nuclear factor erythroid 2-factor 2 (Nrf2), caspase-3, and decreased B-cell lymphoma 2 (Bcl-2), murine double minute 2 (mdm2), and proliferating cell nuclear antigen (PCNA) expression after 48 h. Nymphayol effectively inhibited breast cancer cell viability, and is associated with early expression of Cdkn2a, pRb2, and activation of p53 and caspases.

Enhanced Antimicrobial and Cytotoxicity on Cancer Cell using Bio-Originated Selenium Nanoparticles

Present work describes the bio-originated synthesis of selenium nanoparticles using seed extract of Cassia angustifolia. The biological macromolecules in seed extract react with metal ions to generate selenium nanoparticles. The seed extract acts as reducing, capping and stabilizing agents. The selenium nanoparticles produced by the plant extract are amorphous, nearly spherical in shape and held together by protein coating in a range of about 80-100 nm in size, under ambient conditions. The structural properties of selenium nanoparticles were characterized by UV-visible spectroscopy, FTIR, XRD, FESEM with EDAX, HRTEM and AFM. Antibacterial and antifungal activity of selenium nanoparticles were tested against four bacterial and two fungal strains using standard agar-well diffusion method. The zone of inhibition was observed in the selenium nanoparticles against different microbes and suggested that the bio-originated selenium nanoparticles act as an effective antibacterial and antifungal agent, so it has a great latent in the preparation of drugs used against pathogenic diseases. The cytotoxicity of bio-originated selenium nanoparticles was tested under in vitro conditions on Vero cell line and had compared with MDA-MB231 cancer cell line at different concentrations and the results had proved that bio-originated synthesis selenium nanoparticles can inhibit the growth of human breast-cancer cells by concentration-dependent manner.

NADPH: Quinone oxidoreductase 1 (NQO1) mediated anti-cancer effects of plumbagin in endocrine resistant MCF7 breast cancer cells

BackgroundPLB is a natural naphthoquinone compound isolated from the roots of Plumbago indica plant. Our previous study reported the inhibitory effect of Plumbagin (PLB) on human endocrine resistant breast cancer cell growth and cell invasion. Hypothesis/PurposeSince PLB is a naphthoquinone compound, it can be reduced by the cytosolic NADPH: quinone oxidoreductase 1 (NQO1) enzyme. NQO1 expression is upregulated in various types of aggressive cancer including breast cancer. This study investigated the impact of NQO1 on anti-cancer effects of PLB in endocrine-resistant breast cancer cells. Study DesignThis study was an in vitro study using ER-positive cell line (MCF7) and endocrine-resistant cell lines (MCF7/LCC2 and MCF7/LCC9 cells). MethodsThe roles of NQO1 in anti-cancer activity of PLB were investigated by using NQO1 knockdown cells, NQO1 inhibitor and NQO1 overexpressed cells. To study the impact of NQO1 on the effects of PLB on cell viability, apoptosis, invasion and generation of ROS, the following assays were used: MTT assays, annexin V-PE/7-ADD staining flow cytometry, matrigel invasion assays and DCFHDA assays. To study the mechanism of how NQO1 mediated PLB effects in tamoxifen response and apoptosis, we assessed the levels of mRNA expression by using qRT-PCR. Results1. In this study, NQO1 was upregulated in endocrine-resistant cells.2. PLB did not change the expression of NQO1 but it was able to increase NQO1 activity.3. The inhibitory effects of PLB on cell proliferation, cell invasion and expression of tamoxifen resistant gene were attenuated in NQO1 knockdown cells or in the presence of NQO1 inhibitor.4. The effects of PLB to induce apoptosis and generate ROS were also decreased when NQO1 activity was inhibited or when the NQO1 expression was reduced.5. The anti-cancer effects of PLB increased when NQO1 was upregulated. ConclusionThe effects of PLB in endocrine-resistant breast cancer cells is dependent on NQO1’s activity.

Abstract 3250: B cell-produced IL-27 up-regulates PD-L1 expression in the tumor microenvironment to promote breast cancer development

Abstract The host immune response can be evaded by tumor cells, e.g., through upregulation of the PD-L1/PD-1 immune checkpoint, and - paradoxically - even hijacked to promote cancer progression. Here we showed that B lymphocytes, which can produce anti-tumoral antibodies/autoantibodies in breast cancer (BCa), played an important role in promoting murine BCa development, as B cell-deficient μMT mice displayed virtually abrogated tumor growth from transplanted syngeneic ERα+ breast adenocarcinoma cells, concomitant with significantly reduced PD-L1 expression and much increased cell death in residual tumors. In BCa that grew in wildtype mice and in tumor-associated ectopic lymph nodes, B cells were the major source of IL-27, which is the IL-27p28/EBI3 heterodimer and a pleotropic cytokine with both pro- and anti-inflammatory functions. Deficiency in IL-27 expression specifically in B cells also significantly reduced the BCa growth, indicating that the effect of B cells in BCa development was mainly through IL-27 production. This was effectively induced in B cells primed by TLR ligands, including those that would be released during uncontrolled cell death in the tumor microenvironment, and stimulated by CD154 and IL-21, as likely expressed by activated tumor-infiltrating CD4+ T cells. IL-27 in turn triggered JAK-dependent STAT1 and STAT3 phosphorylation in BCa cells, enhanced PD-L1 gene expression and promoted growth of these cells. In addition, among the 2040 genes compiled by the Ingenuity Pathway Analysis as involved in BCa tumorigenesis, those encoding PD-L1, IFN-γ and Hif-1α (cytokine and transcription factor known to induce PD-L1, respectively), IDO-1, chemokine receptor CXCR3 and its ligand CXCL10 were specifically upregulated in B cells by IL-27, which also induced an overall gene signature similar to what induced by IFN-γ, reflecting the activation of STAT1 and STAT3 by both cytokines. In humans, the two genes encoding IL-27 receptor subunits were highly expressed in the breast tissue, at levels comparable to those in lymphoid organs. As shown by The Cancer Genome Atlas (TCGA) and The Kaplan Meier Plotter datasets, the higher IL27p28 expression was associated with worse survival in BCa patients overall, who displayed increased circulating IL-27 levels as compared to healthy subjects, and in ER+ BCa patients after endocrine therapies. Indeed, IL-27 supported human BCa cell growth in the presence of tamoxifen, suggesting a role of B cell-produced IL-27 in the acquisition of drug resistance by BCa. Thus, TLR-fueled IL-27 induction in B cells reinforces PD-L1 expression in the tumor environment to drive BCa cell-intrinsic growth mechanisms and generation of PD-L1+ B regulatory cells involved in the immune checkpoint, leading to BCa progression and possibly anti-estrogen therapy resistance. Citation Format: Hui Yan, Suryavathi Viswanadhapalli, Daniel Chupp, Maria Fernandez, Shuai Wu, Jingwei Wang, Justin Moroney, Julia Taylor, John Im, Carlos Rivera, Yiliao Luo, Junhao Liu, Gangadhara Sareddy, Paolo Casali, Ratna Vadlamudi, Zhenming Xu. B cell-produced IL-27 up-regulates PD-L1 expression in the tumor microenvironment to promote breast cancer development [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3250.

Inhibition of human breast cancer cells (MCF-7 cell line) growth via cell proliferation, migration, and angiogenesis by auraptene of Ferula szowitsiana root extract

The different species of the Ferula (Apiaceae) genus are endemic in central Asia and are used as a medicinal food in Iran. The Ferula szowitsiana has been reported with anti-inflammatory, anti-hypertensive, anti-helicobacter, antileishmanial and cancer chemopreventive activities. Auraptene is one of the main coumarins from Ferula szowitsiana root. Despite the interesting biological properties of Ferula szowitsiana extract, not much information are available regarding the antioxidant, anti-cancer and anti-angiogenic potentials of isolated auraptene against breast cancer cells. Hence, comprehensive biochemical and molecular analyses were conducted to evaluate the antioxidant, antiproliferative, anti-migratory and angiogenic inhibitory activities of auraptene isolated from Ferula szowitsiana root. The obtained results of this study revealed that auraptene illustrated antioxidant activity through inhibiting DPPH free radicals and ferric reducing ability with respective IC50 values of 557.9 and 476.5 µg ml−1. Besides that, the auraptene exhibited strong cytotoxic properties against MCF-7 cell line (IC50:61.3 µg ml−1). The observed anti-tumor activity in human breast cancer cells (MCF-7 cell line) was through inhibition of cell proliferation, migration, and angiogenesis. These results were further confirmed by up-regulation of caspase-3, caspase-8, and down-regulation of MMP2, MMP9, VEGFR-1, and VEGFR-2 genes. Hence, the auraptene could be a promising anticancer agent in complementary chemotherapy and might be utilized in the food industry for the development of functional or enriched foods.

Nuclear Receptor Coactivator 2 Promotes Human Breast Cancer Cell Growth by Positively Regulating the MAPK/ERK Pathway.

As a member of the p160 steroid receptor coactivator (SRC) family, nuclear receptor coactivator 2 (NCOA2) is known to play essential roles in many physiological and pathological processes, including development, endocrine regulation, and tumorigenesis. However, the biological function of NCOA2 in breast cancer is not fully understood. We found that the copy number of the NCOA2 gene was frequently amplified in four breast cancers datasets, varying from 6 to 10%, and the mRNA levels of NCOA2 were also upregulated in 11% of the sequenced cases/patients (TCGA provisional dataset). Next, we confirmed that NCOA2 silencing significantly suppressed cell proliferation in different breast cancer cell lines, by inducing cell cycle arrest and apoptosis. Mechanistically, whole-transcriptome sequencing (RNA-Seq) analysis showed that NCOA2 depletion leads to downregulation of the MAPK/ERK signaling cascade, possibly via downregulating NCOA2's downstream target RASEF. In conclusion, our results suggest NCOA2 as a potential target of therapeutics against breast cancer.

Effect of Piper nigrum ethanolic extract on human breast cancer cell growth and cell migration

Background: Piper nigrum (PN) is widely used as a traditional medicine, which has anti-cancer activity among others. Objective: Our study purposes to illuminate the inhibition of PN effects on breast cancer cells growth and migration along with its mechanisms. Materials and Methods: The piperine in the young fruit of PN extract was determined by the high-performance liquid chromatography method. Growth inhibition with a mechanism of PN extract was studied in the MCF-7 cells using sulforhodamine B assay, cell cycle analysis, colony formation, caspase-3 activity, and reactive oxygen species formation. Furthermore, the anti-migratory effects of PN were investigated using wound healing, matrigel migration, and gelatin zymography assay. Finally, PN mechanism was determined by reverse transcription polymerase chain reaction and Western blotting for the gene and protein levels. Results: Piperine level was showed at a high concentration in the PN extract. Further, the PN extract suppressed Rac1 mRNA expression in the mevalonate (MVA) pathway as well as repressed Rac1 and RhoA protein expression. Interestingly, PN stimulated growth inhibition in dose- and time-dependent as well as being accompanied by increasing the G1 phase arrest and inhibiting cyclin D1 and NF-κB as well as inducing caspase-3 expression. The PN extract inhibited MCF-7 cell migration by reducing matrix metalloproteinases (MMP) 9 protein expression as well as MMP 2, MMP 9, VEGFA, and ICAMP1 gene expression. Conclusion: PN could be herbal medicine for anti-cancer and anti-migratory activities with a correlation to the MVA pathway; therefore, PN maybe deserving further to study as a new candidate for treating breast cancer.

Monopolar Spindle Induced by Isoamericanol A Suppresses Human Breast Cancer Cell (MCF-7) Growth

Monopolar Spindle Induced by Isoamericanol A Suppresses Human Breast Cancer Cell (MCF-7) Growth

MiR‑146a‑5p targets interleukin‑1 receptor‑associated kinase�1 to inhibit the growth, migration, and invasion of breast cancer cells

MicroRNAs (miRNAs) are associated with the formation and progression of many types of cancers. In the present study, the aim was to elucidate the involvement of miR-146a-5p in the regulation of human breast cancer (BC) cell growth and invasion, as well as the mechanisms underlying its effects. Reverse transcription-quantitative polymerase chain reaction results revealed that miR-146a-5p was markedly downregulated in BC tissues relative to those of adjacent normal tissues. miR-146a-5p expression was also markedly downregulated in BC cells. Overexpression of miR-146a-5p significantly suppressed the proliferation, invasion and migration of BC MDA-MB-453 and MCF7 cells. Furthermore, the results indicated that miR-146a-5p downregulated the expression of interleukin-1 receptor-associated kinase 1 (IRAK1) by directly binding to its 3′-untranslated region in BC cells. Furthermore, IRAK1 expression was observed to be markedly upregulated and inversely correlated with miR-146a-5p expression in BC tissues. Mechanical studies indicated that restoring IRAK1 expression reversed the miR-146a-5p-induced inhibitory effects on proliferation and invasion of BC cells. In conclusion, miR-146a-5p may act as a tumor suppressor in BC by directly targeting IRAK1. These results highlighted the potential of miR-146a-5p as a novel therapeutic target for the treatment of BC.

Antiproliferative and apoptotic activity of glycyrrhizinic acid in MCF-7 human breast cancer cells and evaluation of its effect on cell cycle, cell migration and m-TOR/PI3K/Akt signalling pathway.

IntroductionGlycyrrhizinic acid is a natural product of pharmacological relevance and its anticancer activity against breast cancer cell lines has not been evaluated. Therefore the main purpose of the present study was to investigate the anticancer effects of glycyrrhizinic acid in MCF-7 human breast cancer cells.Material and methodsThe MTT assay was used to evaluate the anticancer effects while a clonogenic assay was used to study its effects on colony formation tendency. Flow cytometry was used to study the effects on cell cycle phase distribution and apoptosis. Western blot assay was used to study changes in protein expression of the m-TOR/PI3K/Akt pathway.ResultsThe results indicated that glycyrrhizinic acid caused significant (p < 0.01). The growth inhibitory effects MCF-7 human breast cancer cells. The growth inhibitory effects of glycyrrhizinic acid exhibited concentration-dependent as well as time-dependent growth inhibitory trend. Different doses of glycyrrhizinic acid had a tendency to significantly (p < 0.01) inhibit the colony formation tendency of MCF-7 cells. As compared to the control group, glycyrrhizinic acid-treated cells showed a high percentage of apoptotic cells. Cells treated with a 10, 50 and 100 µM dose of glycyrrhizinic acid led to a 24.3%, 41.5% and 82.1% increase in the sub-G1 phase (apoptotic) cells. Glycyrrhizinic acid also led to significant (p < 0.01) inhibition of cell invasion along with downregulation of m-TOR/PI3K/Akt protein expression.ConclusionsGlycyrrhizinic acid inhibited MCF-7 human breast cancer cell growth and therefore may prove essential lead molecule in the treatment of breast cancer.