Normal Breast Epithelial Cells Research Articles

Loss of myosin light chain kinase induces the cellular senescence associated secretory phenotype to promote breast epithelial cell migration

Overexpression or activation of oncogenes or loss of tumor-suppressor genes can induce cellular senescence as a defense mechanism against tumor development, thereby maintaining cellular homeostasis. However, cancer cells can circumvent this senescent state and continue to spread. Myosin light chain kinase (MLCK) is downregulated in many breast cancers. Here we report that downregulation of MLCK in normal breast epithelial cells induces a senescence-associated secretory phenotype and stimulates migration. The reduction of MLCK results in increased p21Cip1 expression, dependent on p53 and the AKT-mammalian target of rapamycin pathway. Subsequently, p21Cip1 promotes the secretion of soluble ICAM-1, IL-1α, IL-6 and IL-8, thereby enhancing collective cell migration in a non-cell-autonomous manner. These findings provide new mechanistic insights into the role of MLCK in cellular senescence and cancer progression.

Activation of Mammary Epithelial and Stromal Fibroblasts upon Exposure to Escherichia coli Metabolites.

Breast cancer is the leading cause of cancer death among women worldwide. The mammary gland is composed of various types of cells including luminal cells, fibroblasts, immune cells, adipocytes, and specific microbiota. The reciprocal interaction between these multiple types of cells can dictate the initiation and progression of cancer, as well as metastasis and response to therapy. In the present report, we have shown that Escherichia coli-conditioned media (E-CM) can directly activate human mammary luminal epithelial cells (HMLEs), by inducing epithelial-to-mesenchymal transition (EMT), a process associated with increased proliferation and invasion capacities, as well as stemness features. Additionally, it has been shown that E-CM has an indirect pro-carcinogenic effect, mediated by the activation of normal breast fibroblasts (NBFs). Indeed, E-CM upregulated various markers of active fibroblasts (FAP-α, GPR77, and CD10), and enhanced the proliferation, migration, and invasion capacities of NBFs. Furthermore, E-CM induced an inflammatory response in NBFs by activating the pro-inflammatory NF-kB transcription factor and several of its downstream target cytokines including IL-1β, IL-6, and IL-8. This E-CM-dependent activation of NBFs was confirmed by showing their paracrine pro-carcinogenic effects through inducing EMT and stemness features in normal breast epithelial cells. Interestingly, similar effects were obtained by recombinant human IL-1β. These results provide the first indication that E. coli can initiate breast carcinogenesis through the activation of breast stromal fibroblasts and their paracrine pro-carcinogenic effects.

Anticancer Properties Against Select Cancer Cell Lines and Metabolomics Analysis of Tender Coconut Water.

Tender Coconut Water (TCW) is a nutrient-rich dietary supplement that contains in bioactive secondary metabolites and phytohormones with anti-oxidative and anti-inflammatory properties. Studies on TCW's anti-cancer properties are limited and the mechanism of its anti-cancer effects have not been defined. In the present study, we investigate TCW for its anti-cancer properties and, using untargeted metabolomics, we identify components form TCW with potential anti-cancer activity. Cell viability assay, BrdU incorporation assay, soft-agar assay, flow-cytometery, and Western blotting were used to analyze TCW's anticancer properties and to identify mechanism of action. Liquid chromatography- Tandem Mass Spectroscopy (LC-MS/MS) was used to identify TCW components. TCW decreased the viability and anchorage-independent growth of HepG2 hepatocellular carcinoma (HCC) cells and caused S-phase cell cycle arrest. TCW inhibited AKT and ERK phosphorylation leading to reduced ZEB1 protein, increased E-cadherin, and reduced N-cadherin protein expression in HepG2 cells, thus reversing the 'epithelial-to-mesenchymal' (EMT) transition. TCW also decreased the viability of Hep3B hepatoma, HCT-15 colon, MCF-7 and T47D luminal A breast cancer (BC) and MDA-MB-231 and MDA-MB-468 triplenegative BC cells. Importantly, TCW did not inhibit the viability of MCF-10A normal breast epithelial cells. Untargeted metabolomics analysis of TCW identified 271 metabolites, primarily lipids and lipid-like molecules, phenylpropanoids and polyketides, and organic oxygen compounds. We demonstrate that three components from TCW: 3-hydroxy-1-(4-hydroxyphenyl)propan-1-one, iondole-3-carbox aldehyde and caffeic acid inhibit the growth of cancer cells. TCW and its components exhibit anti-cancer effects. TCW inhibits the viability of HepG2 hepatocellular carcinoma cells by reversing the EMT process through inhibition of AKT and ERK signalling.

NCAM and attached polysialic acid affect behaviors of breast epithelial cells through differential signaling pathways.

Neural cell adhesion molecule (NCAM), a common mammalian cell surface glycoprotein, is the major substrate of polysialic acid (polySia). Polysialylated NCAM occurs in many types of cancer, but rarely in normal adult tissues. The functional role of NCAM hypersialylation in the epithelial-mesenchymal transition (EMT) process remains unclear. The present study indicates that NCAM and attached polysialic acid affect behaviors of breast epithelial cells through differential signaling pathways. NCAM and polysialylated NCAM are aberrantly regulated in breast cancer cells. They are both upregulated in normal breast epithelial cells undergoing EMT. Western blot analysis demonstrates that NCAM-140 overexpression induces EMT in breast epithelial cells and promotes cell proliferation and migration through activation of the β-catenin/slug signaling pathway. Modification of polySia attached to NCAM modulates cell adhesion and promotes cell motility through activation of the EGFR/STAT3 pathway. These observations contribute to clarifying the molecular mechanisms by which polysialic acid and its major substrate, NCAM, modulate cell behaviors, and highlight the significance of increased polysialylated expression on NCAM during EMT and tumor development.

Revealing the Molecular Signatures of miR-185-5p on Breast Cancer Cells Using Proteomic Analysis.

Breast cancer is a heterogeneous type of disease in which genetic and environmental factors play a crucial role. There are several types of treatment for breast cancer (BC) patients. However, the biggest problem in the treatment of breast cancer is the resistance that occurs during the treatment with chemotherapeutic agents. Usnic acid, a secondary metabolite of lichen, has been identified as a drug candidate molecule in cancer treatment. The determination of miRNA target proteins is essential for the understanding of molecular mechanisms of miRNA-related tumorigenesis. We determined that mir-185-5p has therapeutic potential at the miRNA level by applying usnic acid to BT-474 breast cancer cells in a previous study. Herein, we aimed to investigate the molecular mechanisms of miR-185-5p on BT-474 breast cancer cells using a proteomics approach. We explored the changes in the protein expression level of BT-474 breast cancer cells in response to the up-regulation of miR-185-5p after applying usnic acid as a novel candidate anti-- cancer drug molecule. We performed quantitative proteome analysis based on an LC-MS/MS assay, which was validated by western blotting. The differentially expressed proteins were analyzed using the latest data available in bioinformatics tools. The up-regulated expression of YWHAE, Cathepsin D, and the down-regulated levels of PAK-1 were demonstrated by western blot assay. According to the results, 86 proteins showing >2-fold change were identified as differentially expressed between breast cancer and normal breast epithelial cells. The apoptosis pathway was the main clade containing most of the proteins regulated by miR-185-5p. The results indicate that miR-185-5p modulates apoptosis signaling pathways in BT-474 breast cancer cells. Breast cancer inhibition due to increased expression of YWHAE, Cathepsin D, and decreased expression of PAK-1 is likely to be mediated by inducing miR-185-5p mediated apoptosis. In this study, the identification of miR-185-5p protein targets demonstrated the potential for the development of targeted therapy and the development of miRNA-based therapeutics and presented it as a biomarker for breast cancer diagnosis, prognosis, and treatment response. In this regard, proteome analyses provided an understanding of the molecular mechanism underlying the effect of miR-185-5p on breast cancer.

Stimulated Brillouin scattering flow cytometry.

We present the use of stimulated Brillouin scattering spectroscopy to achieve rapid measurements of cell biomechanics in a flow cytometer setup. Specifically, our stimulated Brillouin scattering flow cytometry can acquire at a rate of 200 Hz, with a spectral acquisition time of 5 ms, which marks a 10x improvement compared to previous demonstrations of spontaneous Brillouin scattering flow cytometry. We experimentally validate our stimulated Brillouin scattering flow cytometer by measuring cell populations of normal breast epithelial cells and metastatic breast epithelial cancer cells.

Cytoarchitecture of Breast Cancer Cells under Diabetic Conditions: Role of Regulatory Kinases-Rho Kinase and Focal Adhesion Kinase.

Diabetes greatly reduces the survival rates in breast cancer patients due to chemoresistance and metastasis. Reorganization of the cytoskeleton is crucial to cell migration and metastasis. Regulatory cytoskeletal protein kinases such as the Rho kinase (ROCK) and focal adhesion kinase (FAK) play a key role in cell mobility and have been shown to be affected in cancer. It is hypothesized that diabetes/high-glucose conditions alter the cytoskeletal structure and, thus, the elasticity of breast cancer cells through the ROCK and FAK pathway, which can cause rapid metastasis of cancer. The aim of the study was to investigate the role of potential mediators that affect the morphology of cancer cells in diabetes, thus leading to aggressive cancer. Breast cancer cells (MDA-MB-231 and MCF-7) were treated with 5 mM glucose (low glucose) or 25 mM glucose (high glucose) in the presence of Rho kinase inhibitor (Y-27632, 10 mM) or FAK inhibitor (10 mM). Cell morphology and elasticity were monitored using atomic force microscopy (AFM), and actin staining was performed by fluorescence microscopy. For comparative study, normal mammary breast epithelial cells (MCF-10A) were used. It was observed that high-glucose treatments modified the cytoskeleton of the cells, as observed through AFM and fluorescence microscopy, and significantly reduced the elasticity of the cells. Blocking the ROCK or FAK pathway diminished the high-glucose effects. These changes were more evident in the breast cancer cells as compared to the normal cells. This study improves the knowledge on the cytoarchitecture properties of diabetic breast cancer cells and provides potential pathways that can be targeted to prevent such effects.

Front Cover Image

ON THE FRONT COVER: Normal human breast epithelial cells expressing GFP‐LIMD1 (green) and tained for F‐actin (red) and DNA (blue).Credit: Samriddha Ray, Chamika DeSilva, Natasha Cruz‐Calderon and Daniel McCollum. University of Massachusetts Chan Medical School Department of Biochemistry and Molecular Biotechnology. image

Intracellular pH differentially regulates transcription of metabolic and signaling pathways in normal epithelial cells

Intracellular pH (pHi) dynamics regulate normal cell function, and dysregulated pHi dynamics is an emerging hallmark of cancer (constitutively increased pHi) and neurodegeneration (constitutively decreased pHi). However, the molecular mechanisms by which pHi dynamics regulate cell biology are poorly understood. Here, we discovered that altering pHi in normal human breast epithelial cells triggers global transcriptional changes. We identified 176 genes differentially regulated by pHi, with pHi-dependent genes clustering in signaling and glycolytic pathways. Using various normal epithelial cell models, we showed pH-dependent Notch homolog 1 protein expression, with increased protein abundance at high pHi. This resulted in pH-dependent downstream signaling, with increased Notch homolog 1 signaling at high pHi. We also found that high pHi increased the expression of glycolytic enzymes and regulators of pyruvate fate, including lactate dehydrogenase and pyruvate dehydrogenase kinase. These transcriptional changes were sufficient to alter lactate production, with high pHi shifting these normal epithelial cells toward a glycolytic metabolism and increasing lactate production. Thus, pHi dynamics transcriptionally regulate signaling and metabolic pathways in normal epithelial cells. Our data reveal new molecular regulators of pHi-dependent biology and a role for increased pHi in driving the acquisition of cancer-associated signaling and metabolic changes in normal human epithelial cells.

Chemical Implications of apo-8, 6' Carotendial versus Intact Lycopene on Mechanism of Enhanced Cell-cell Communication and Apoptosis Induction in Breast Cancer Cells.

Investigation on carotenoids and its cleavage products is crucial to combat the development of chronic diseases, including cancer. Therefore, this study aimed to explore the effect of lycopene oxidative products versus equivalent concentration of lycopene (LYC) on major molecular events of cancer cells (MCF-7). Primarily, LYC-oxidized products were generated chemically, then collected its rich fraction. Based on cell-based assays, the antiproliferation potency of rich fraction of chemically-oxidized lycopene (COL) identified as apo-8, 6' carotendial was compared with LYC. Interestingly, the inhibition of cell migration by COL strongly demonstrated anti-metastatic activity. Further, the increased connexin-43 expression confirms enhanced gap-junctional communication activity of COL than LYC and control. Fortunately, apo-8, 6' carotendial did not affect normal breast epithelial cells. We anticipated that, the chemical properties of apo-8, 6'-carotendial is similar and mimic a model compound acrolein (α, β-conjugated aldehyde) which is involved in Michael addition/Schiff base formation with specific amino acids and regulates redox signaling, reactive oxygen species sensing and cellular buffering. The chemistry of apo-8, 6' carotendial reveals a greater insight into the mechanism of selective inhibition of cancer cells proliferation. In this context, speculations of putative action of lycopeneoids through chemical biology approach facilitate greater insights in tandem with synthetic chemistry.

Distinctive expression and cellular localisation of zinc homeostasis-related proteins in breast and prostate cancer cells

BackgroundZinc transport proteins (ZIP and ZnT), metallothioneins (MT) and protein kinase CK2 are involved in dysregulation of zinc homeostasis in breast and prostate cancer cells. Following up our previous research, we targeted ZIP12, ZnT1, MT2A and CK2 in this study by investigating their expression levels and protein localisation. MethodsQuantitative reverse transcription polymerase chain reaction (qRT-PCR) and immunofluorescence confocal microscopy were employed to quantify the expression of ZIP12, ZnT1, MT2A and CK2 subunits in a panel of breast and prostate cell lines without or with extracellular zinc exposure. The cellular localisations of these target proteins were also examined by immunofluorescence confocal microscopy. ResultsIn response to the extracellular zinc exposure, the gene expression was elevated for SLC39A12 (ZIP12), SLC30A1 (ZnT1) and MT2A (MT2A) in normal prostate epithelial cells (RWPE-1) in contrast to their cancerous counterparts (PC3 and DU145), whilst the gene expression was higher for SLC39A12 (ZIP12) and SLC30A1 (ZnT1) in both normal (MCF10A) and basal breast cancer cells (MDA-MB-231) compared to luminal breast cancer cells (MCF-7). At the protein level, the expression for both ZIP12 and ZnT1 was trending lower in the time course for the breast cancer cells whilst their expression was remained constant in the normal breast epithelial cells. The expression of ZIP12 in prostate cancer cells was higher than the normal prostate cells. The protein expression for CK2 α/αꞌ and CK2β was markedly higher in prostate cancer cells than the normal prostate cells. Upon extracellular zinc exposure, ZIP12 was, for the first time, conspicuously localised in the plasma membrane of breast cancer cells but not in normal breast epithelial cells and prostate cells. ZnT1 is only localised in the plasma membrane of breast cancer cells. MT2A is distinctively seen close to the plasma membrane in breast cancer cells. CK2 is also for the first time shown to be localised in proximity to the plasma membrane of breast cancer cells. ConclusionThe findings, particularly the localisation of ZIP12 and CK2, are novel and significant for our understanding of zinc homeostasis in breast and prostate cancer cells.

Perfluorooctanesulfonic acid (PFOS) induced cancer related DNA methylation alterations in human breast cells: A whole genome methylome study

DNA methylation plays a pivotal role in cancer. The ubiquitous contaminant perfluorooctanesulfonic acid (PFOS) has been epidemiologically associated with breast cancer, and can induce proliferation and malignant transformation of normal human breast epithelial cells (MCF-10A), but the information about its effect on DNA methylation is sparse. The aim of this study was to characterize the whole-genome methylome effects of PFOS in our breast cell model and compare the findings with previously demonstrated DNA methylation alterations in breast tumor tissues. The DNA methylation profile was assessed at single CpG resolution in MCF-10A cells treated with 1 μM PFOS for 72 h by using Enzymatic Methyl sequencing (EM-seq). We found 12,591 differentially methylated CpG-sites and 13,360 differentially methylated 100 bp tiles in the PFOS exposed breast cells. These differentially methylated regions (DMRs) overlapped with 2406 genes of which 494 were long non-coding RNA and 1841 protein coding genes. We identified 339 affected genes that have been shown to display altered DNA methylation in breast cancer tissue and several other genes related to cancer development. This includes hypermethylation of GACAT3, DELEC1, CASC2, LCIIAR, MUC16, SYNE1 and hypomethylation of TTN and KMT2C. DMRs were also found in estrogen receptor genes (ESR1, ESR2, ESRRG, ESRRB, GREB1) and estrogen responsive genes (GPER1, EEIG1, RERG). The gene ontology analysis revealed pathways related to cancer phenotypes such as cell adhesion and growth. These findings improve the understanding of PFOS's potential role in breast cancer and illustrate the value of whole-genome methylome analysis in uncovering mechanisms of chemical effects, identifying biomarker candidates, and strengthening epidemiological associations, potentially impacting risk assessment.

Dual-targeting class I HDAC inhibitor and ATM activator, SP-1-303, preferentially inhibits estrogen receptor positive breast cancer cell growth.

Dual-targeting chromatin regulation and DNA damage repair signaling presents a promising avenue for cancer therapy. Applying rational drug design, we synthesized a potent dual-targeting small molecule, SP-1-303. Here, we report SP-1-303 as a class I isoform selective histone deacetylase (HDAC) inhibitor and an activator of the ataxia-telangiectasia mutated protein (ATM). In vitro enzymatic assays demonstrated selective inhibition of HDAC1 and HDAC3. Cellular growth inhibition studies show that SP-1-303 differentially inhibits growth of estrogen receptor positive breast cancer (ER+ BC) cells with effective growth inhibition concentrations (EC50) for MCF-7 and T47D cells ranging from 0.32 to 0.34 μM, compared to 1.2-2.5 μM for triple negative breast cancer cells, and ~12 μM for normal breast epithelial cells. Western analysis reveals that SP-1-303 decreases estrogen receptor alpha (ER-α) expression and increases p53 protein expression, while inducing the phosphorylation of ATM and its substrates, BRCA1 and p53, in a time-dependent manner in ER+ BC cells. Pharmacokinetic evaluation demonstrates an area under the curve (AUC) of 5227.55 ng/ml × h with an elimination half-life of 1.26 h following intravenous administration in a rat model. Collectively, SP-1-303 emerges as a novel second generation class I (HDAC1 and HDAC3) selective HDAC inhibitor, and ATM activator, capable of modulating ER expression, and inhibiting growth of ER+ BC cells. Combined targeting of class I HDACs and ATM by SP-1-303 offers a promising therapeutic approach for treating ER+ breast cancers and supports further preclinical evaluation.

Bis‐Ureido‐Substituted Benzenesulfonamides: Evaluation of Their Antibacterial, Anticholinesterase, and Cytotoxicity Properties

AbstractIn this study, we present the re‐synthesis of a series of twelve bis‐ureido‐substituted benzenesulfonamides, focusing on their potential as antibacterial, anticholinesterase, and cytotoxic agents. First, the antibacterial assessment of these compounds indicated varying activity levels across different bacterial strains, with S. aureus displaying resistance to all compounds, while compounds 9 and 11 exhibited promise against E. faecalis with a MIC value of 31.25 μg/mL. Additionally, P. aeruginosa showed resistance to compounds containing 4‐aminobenzene sulfonamides, whereas derivatives such as (8–11) and compound 19 displayed notable activity against E. coli, comparable to Ampicillin. Second, their anticholinesterase activities were examined, with a focus on their potential role in addressing neurological disorders, particularly Alzheimer′s disease. The findings indicated that all synthesized compounds showed a significant inhibitory effect on both AChE and BChE enzymes. Compound 11 demonstrated the most effective inhibition on the AChE enzyme with an IC50 value of 0.2160±0.09 nM, while compound 18 exhibited the most potent inhibition on the BChE enzyme with an IC50 value of 0.2257±0.06 nM. Finally, cytotoxicity studies were conducted across various cell lines, including breast, lung, and prostate cancer cells and normal cells. The results revealed that compound 12 emerged as the most potent tested compound against breast cancer cells with no cytotoxic effect on CRL‐4010 normal breast epithelial cells. The research presented here not only highlights the multifaceted pharmacological potential of bis‐ureido‐substituted benzenesulfonamides, but also indicates their potential as versatile compounds for antibacterial, anticholinesterase, and cytotoxicity applications, opening up new avenues for drug discovery and development.

Rutaecarpine-inspired scaffold-hopping strategy and Ullmann cross-coupling based synthetic approach: Identification of pyridopyrimidinone-indole based novel anticancer chemotypes

Natural products as starting templates have shown historically major contribution to development of drugs. Inspired by the structure–function of an anticancer natural alkaloid Rutaecarpine, the Scaffold-hopped Acyclic Analogues of Rutaecarpine (SAAR) with ‘N’-atom switch (1°-hop) and ring-opening (2°-hop) were investigated. A new synthetic route was developed for an effective access to the analogues, i.e. 2-indolyl-pyrido[1,2-a]pyrimidinones, which involved preparation of N-Boc-N’-phthaloyltryptamine/mexamine-bromides and pyridopyrmidinon-2-yl triflate, a nickel/palladium-catalysed Ullmann cross-coupling of these bromides and triflate, deprotection of phthalimide followed by N-aroylation, and Boc-deprotection. Fourteen novel SAAR-compounds were prepared, and they showed characteristic antiproliferative activity against various cancer cells. Three most active compounds (11a, 11b, and 11c) exhibited good antiproliferative activity, IC50 7.7–15.8 µM against human breast adenocarcinoma cells (MCF-7), lung cancer cells (A549), and colon cancer cells (HCT-116). The antiproliferative property was also observed in the colony formation assay. The SAAR compound 11b was found to have superior potency than original natural product Rutaecarpine and an anticancer drug 5-FU in antiproliferative activities with relatively lower cytotoxicity towards normal breast epithelial cells (MCF10A) and significantly higher inhibitory effect on cancer cells’ migration. The compound 11b was found to possess favourable in silico physicochemical characteristics (lipophilicity-MLOGP, TPSA, and water solubility-ESOL, and others), bioavailability score, and pharmacokinetic properties (GI absorption, BBB non-permeant, P-gp, and CYP2D6). Interestingly, the compound 11b did not show any medicinal chemistry structural alert of PAINS and Brenk filter. The study represents for the first time the successful discovery of new potent anticancer chemotypes using Rutaecarpine natural alkaloid as starting template and reaffirms the significance of natural product-inspired scaffold-hopping technique in drug discovery research.

Exosomal HMGB1 educate PD-L1+-tumor associated macrophages via glycometabolic reprogramming to induce lung-tropic metastasis of triple negative breast cancer.

1090 Background: Lung metastasis occurs in one third of triple negative breast cancer (TNBC), the underlying molecular mechanism remains largely unclear. Mounting evidence suggests that PD-L1+-tumor associated macrophages (PD-L1+-TAMs) are closely associated with immune suppression, invasion, and metastasis. Tumor-derived exosomes have been reported to remodel tumor microenvironment and accelerate metastasis through packing and delivering a variety of biologically active molecules. The aim of this study was to investigate whether TNBC-derived exosomes were able to polarize lung macrophages towards PD-L1+-TAMs and promote a pre-metastatic immunosuppressive niche, therefore discovering the underlying mechanism of lung-tropic metastasis. Methods: Exosomes obtained from EO771 TNBC cell line (EO771/exo) and HC11 normal breast epithelial cell line (HC11/exo) were characterized. Absorption of exosomes by macrophages was observed by confocal microscopy. Mass spectrometry was used to identify the significantly highly expressed HMGB1 protein in EO771/exo, and ligands of HMGB1 on lung macrophages were detected by co-immunoprecipitation. Significance of EO771/exo and HMGB1 in inducing PD-L1+-TAMs and generating a pre-metastatic immunosuppressive niche were confirmed by both in vitro and in vivo studies. Functions of EO771/exo and HMGB1 on glycolysis and lactate production were evaluated by metabolism assays. Results: EO771/exo could polarize macrophages toward PD-L1+-TAMs and generate a pre-metastatic immunosuppressive niche. Mass spectrometry, clinical samples, and bioinformatics analysis showed that HMGB1 was significantly expressed in EO771/exo and was involved in cellular communication and metabolism processes. Co-immunoprecipitation and 3-dimensional modeling suggested a strong binding of HMGB1 with Tim-3 ligand on lung macrophages. Macrophages incubated with EO771/exo exhibited an enhanced glycolysis and lactate production. Flow cytometry demonstrated that green fluorescent protein (GFP)-EO771 tumor-bearing mice had more lung micro-metastases than brain and liver. Immunofluorescence and laser confocal microscopy demonstrated that EO771/exo were able to increase lung micro-metastases and escalate PD-L1 expression on lung macrophages. Moreover, elevated PD-L1+-TAMs and reduced CD3+CD8+ T lymphocytes were detected in TNBC positive axillary lymph nodes and lung metastasis specimens than TNBC negative axillary lymph nodes. Conclusions: Exosomal HMGB1 from TNBC could target Tim-3 ligand on lung macrophages and accelerate glycolysis and lactate production to induce PD-L1+-TAMs, thereby suppressing CD3+CD8+ T lymphocytes immunity and generating a pre-metastasis immune-suppressive niche. Our research would uncover a novel mechanism of lung-tropic metastasis.

Silencing PCMT1 enhances the sensitivity of breast cancer cells to paclitaxel through the PI3K/Akt/STMN1 pathway.

This study aimed to investigate whether silencing Protein L-isoaspartate (D-aspartate) O-methyltransferase (PCMT1) expression can enhance the sensitivity of breast cancer cells to paclitaxel and its possible mechanism. Tumor tissues and adjacent histologically normal tissues were collected from patients with breast cancer admitted to our hospital. Human normal breast epithelial cells MCF10A, human breast cancer cells MCF-7, and paclitaxel-resistant breast cancer cells MCF-7/PR were purchased. MCF-7/PR cells were further grouped into negative control (NC) group, si-PCMT1 group (transfected with si-PCMT1), 740Y-P group (treated with 740Y-P, an activator of phosphatidylinositol 3-kinase (PI3K)/ v-Akt Murine Thymoma Viral Oncogene (AKT) signaling pathway), and si-PCMT1 + 740Y-P group (transfected with si-PCMT1 and then treated with 740Y-P). The expression level of PCMT1 in tissues and cells was detected by quantitative real-time polymerase chain reaction (qRT-PCR). Western blot analysis was used to detect the protein expression level of PCMT1 in tissues and cells as well as the protein level of p-PI3K, PI3K, p-Akt, Akt, and Stathmin1 (STMN1) in cells. 3-(4,5)-dimethylthiahiazo(-z-y1)-3,5-di-phenytetrazoliumromide (MTT) and colony formation assays were used to determine cell viability, scratch assay was used to assess the migration ability of cells, and Transwell assay was used to assess the invasion ability of cells. The expression of PCMT1 was remarkably up-regulated in breast cancer tissues and MCF-7/PR cells. Silencing PCMT1 expression significantly inhibited the proliferation, migration, and invasion of MCF-7/PR cells, and alleviated the resistance of cancer cells to paclitaxel. Additionally, silencing PCMT1 expression also inhibited the activation of PI3K/Akt/STMN1 pathway in MCF-7/PR cells, while activating PI3K/Akt/STMN1 pathway significantly reversed the effect of silencing PCMT1 expression on MCF-7/PR cells. PCMT1 is highly expressed in breast cancer tissues and MCF-7/PR cells, and silencing PCMT1 expression can not only inhibit the development of breast cancer but also enhance paclitaxel sensitivity. Its mechanism of action may be achieved by inhibiting PI3K/Akt/STMN1 signaling.

Evaluation of anticancer activity of novel platinum(II) bis(thiosemicarbazone) complex against breast cancer

The study aims to synthesize a novel bis(thiosemicarbazone) derivative based on platinum (thioPt) and evaluate its anticancer properties against MFC-7 and MDA-MB-231 breast cancer cells. A new platinum complex was synthesised by reacting K2PtCl4 with 2,2′-(1,2-diphenylethane-1,2-diylidene)bis(hydrazine-1-carbothioamide) in ethanol in the presence of K2CO3. In the obtained complex, the platinum atom is coordinated by a conjugated system = N-NC-S-The structures of the new compound were characterised using NMR spectroscopy, HR MS, IR, and X-ray structural analysis. The obtained results of the cytotoxicity assay indicate that compound thioPt had potent anticancer activity (MCF-7: 61.03 ± 3.57 µM, MDA-MB-231: 60.05 ± 5.40 µM) with less toxicity against normal MCF-10A breast epithelial cells, even compared to the reference compound (cisplatin). In addition, subsequent experiments found that thioPt induces apoptosis through both an extrinsic (↑caspase 8 activity) and intrinsic (↓ΔΨm) pathway, which ultimately leads to an increase in active caspase 3/7 levels. The induction of autophagy and levels of proteins involved in this process (LC3A/B and Beclin-1) were examined in MCF-7 and MDA-MB-231 breast cancer cells exposed to tested compounds (thio, thioPt, cisPt) at a concentration of 50 µM for 24 h. Based on these results, it can be concluded that thio and thioPt do not significantly affect the autophagy process. This demonstrates their superiority over cisplatin, which can stimulate cancer cell survival through its effect on stimulation of autophagy.

Exposure to Selenomethionine and Selenocystine Induces Redox-Mediated ER Stress in Normal Breast Epithelial MCF-10A Cells.

Selenium is an essential trace element co-translationally incorporated into selenoproteins with important biological functions. Health benefits have long been associated with selenium supplementation. However, cytotoxicity is observed upon excessive selenium intake. The aim of this study is to investigate the metabolic pathways underlying the response to the selenium-containing amino acids selenomethionine and selenocysteine in a normal human breast epithelial cell model. We show that both selenomethionine and selenocystine inhibit the proliferation of non-cancerous MCF-10A cells in the same concentration range as cancerous MCF-7 and Hela cells, which results in apoptotic cell death. Selenocystine exposure in MCF-10A cells caused a severe depletion of free low molecular weight thiols, which might explain the observed upregulation of the expression of the oxidative stress pathway transcription factor NRF2. Both selenomethionine and selenocystine induced the expression of target genes of the unfolded protein response (GRP78, ATF4, CHOP). Using a redox-sensitive fluorescent probe targeted to the endoplasmic reticulum (ER), we show that both selenoamino acids shifted the ER redox balance towards an even more oxidizing environment. These results suggest that alteration of the redox state of the ER may disrupt protein folding and cause ER stress-induced apoptosis in MCF-10A cells exposed to selenoamino acids.

Enhancing therapeutic efficacy: sustained delivery of 5-fluorouracil (5-FU) via thiolated chitosan nanoparticles targeting CD44 in triple-negative breast cancer

Our current study reports the successful synthesis of thiolated chitosan-based nanoparticles for targeted drug delivery of 5-Fluorouracil. This process was achieved through the ionic gelation technique, aiming to improve the efficacy of the chemotherapeutic moiety by modifying the surface of the nanoparticles (NPs) with a ligand. We coated these NPs with hyaluronic acid (HA) to actively target the CD44 receptor, which is frequently overexpressed in various solid malignancies, including breast cancer. XRD, FTIR, SEM, and TEM were used for the physicochemical analysis of the NPs. These 5-Fluorouracil (5-FU) loaded NPs were evaluated on MDA-MB-231 (a triple-negative breast cell line) and MCF-10A (normal epithelial breast cells) to determine their in vitro efficacy. The developed 5-FU-loaded NPs exhibited a particle size within a favorable range (< 300 nm). The positive zeta potential of these nanoparticles facilitated their uptake by negatively charged cancer cells. Moreover, they demonstrated robust stability and achieved high encapsulation efficiency. These nanoparticles exhibited significant cytotoxicity compared to the crude drug (p < 0.05) and displayed a promising release pattern consistent with the basic diffusion model. These traits improve the pharmacokinetic profile, efficacy, and ability to precisely target these nanoparticles, offering a potentially successful anticancer treatment for breast cancer. However, additional in vivo assessments of these formulations are obligatory to confirm these findings.