MDA-MB231 Breast Cancer Cells Research Articles

Expression of polymeric immunoglobulin receptor (PIGR) and the effect of PIGR overexpression on breast cancer cells

Polymeric immunoglobulin receptor (PIGR) has a major role in mucosal immunity as a transporter of polymeric immunoglobulin across the epithelial cells. The aim of this study was to determine the effect of PIGR on cellular behaviours and chemo-sensitivity of MCF7 and MDA-MB468 breast cancer cell lines. Basal levels of PIGR mRNA and protein expression in MCF7 and MDA-MB468 cells were evaluated by real time quantitative polymerase chain reaction and Western blotting, respectively. MCF7/PIGR and MDA-MB468/PIGR stable cell lines, overexpressing the PIGR gene, were generated using a lentiviral vector with tetracycline dependent induction of expression. Cell viability, cell proliferation and chemo-sensitivity of PIGR transfected cells were evaluated and compared with un-transfected cells to determine the effect of PIGR overexpression on cell phenotype. The levels of PIGR mRNA and protein expression were significantly higher in MDA-MB468 cells than in MCF7 cells (380-fold, p < 0.0001). However, the differential expression of PIGR in these two cell lines did not lead to significant differences in chemosensitivity. Viral overexpression of PIGR was also not found to change any of the parameters measured in either cell line. PIGR per se did not affect cellular behaviours and chemosensitivity of these breast cancer cell lines.

Does broccoli (brassica oleracea var. italica) extract have a potential therapeutic targets on human breast cancer (MDA-MB-231) using AgNOR detection method?

In this study, it was aimed to determine the in vitro effect of the extract obtained from mature broccoli on the breast cancer cell line. MDA-MB231 breast cancer cell line was used in the study. MDA-MB-231 cells were exposed to broccoli extract at 37°C and 5% CO2 for varying durations (24 and 48 hours) and doses (125 and 250 µl/ml).At the end of the incubation period, viability, apoptosis, cell cycle and AgNOR protein status of MDA-MB-231 cells were examined in the Muse Cell Analyzer. In the groups containing broccoli extract, a decrease in the percentage of viable cells and a significant increase in the percentage of early and total apoptosis were observed for both doses compared to the control. In the cell cycle test, the number of cells in the S phase increased in all groups.It was observed that the groups containing broccoli extract slowed down the cell cycle in the transition to the S checkpoint. AgNOR staining results also supported cell cycle and apopitosis, and AgNOR number and TAA/NA ratio decreased in the 125 µl/ml broccoli extract group after 24-48 hours and were found to be statistically significant compared to the control group. It was determined that broccoli increased apoptosis on breast cancer cells by various mechanisms and inhibited cell viability/cell growth. The results were similar to the results of AgNOR protein synthesis. The study showed that the regular and correct consumption of broccoli could be effective in preventing cancer formation and slowing its progression.

Combined dandelion extract and all-trans retinoic acid induces cytotoxicity in human breast cancer cells

Breast cancer is one of the most prevalent and deadly cancers among women worldwide. Recently, natural compounds have been widely used for the treatment of breast cancer. Present study evaluated antiproliferative and anti-metastasis activities of two natural compounds of dandelion and all-trans-retinoic acid (ATRA) in human MCF-7 and MDA-MB231 breast cancer cells. We also evaluated the expression of MMP-2, MMP-9, IL-1β, p53, NM23 and KAI1 genes. Data showed a clear additive cytotoxic effect in concentrations of 40 μM ATRA with 1.5 and 4 mg/ml of dandelion extract in MCF-7 and MDA-MB231 cells, respectively. In both cell lines, compared with the untreated cells, the expression levels of MMP-9 and IL-1β were significantly decreased while p53 and KAI1 expression levels were increased. Besides, MMP-2 and NM23 had different expressions in the two studied cell lines. In conclusion, dandelion/ATRA co-treatment, in addition to having strong cytotoxic effects, has putative effects on the expression of anti-metastatic genes in both breast cancer cells.

In Vitro Evaluation of Biological and Anticancer Activities Exhibited by Five Varieties of Vitis vinifera L.

Vitis vinifera commonly known as grapevine is one of the most important fruit crops worldwide. Its cultivation started more than 7000 years ago in the Near East, and over the millennia was followed by the development of thousands of cultivars that were further selected and characterized for specific purposes. Its important pharmacological value and its richness in phytoconstituents were the triggers to perform this project. Seven extracts were prepared from five different V. vinifera varieties (V. vinifera 'Black Pearl' (BP), V. vinifera 'Red Glob' (RG), V. vinifera 'Crimson' (CR), V. vinifera 'Beitamouni' (BE) and V. vinifera 'Superior' (SU)) by separating the pulp from the seeds, followed by methanolic extraction. The phytochemical analysis showed that red colored grapes (RE, BP and CR), the seeds from V. vinifera 'Black Pearl' and V. vinifera 'Red Globe' contain higher amounts of primary and secondary metabolites such as polyphenols, anthocyanins and reducing sugars. In addition to their richness in phytoconstituents, these varieties/seeds possess an important antioxidant activity. The results of the cell viability assays showed that the red varieties have a potential anticancer activity against Capan-2 pancreatic cancer and MDA-MB231(TNBC) breast cancer cell lines, with the greatest promise when combined with the seeds.

Fractions of Methanol Extracts from the Resurrection Plant Haberlea rhodopensis Have Anti-Breast Cancer Effects in Model Cell Systems

Breast cancer is among the most problematic diseases and a leading cause of death in women. The methods of therapy widely used, so far, are often with many side effects, seriously hampering patients’ quality of life. To overcome these constraints, new cancer treatment alternatives are constantly tested, including bioactive compounds of plant origin. Our aim was to study the effects of Haberlea rhodopensis methanol extract fractions on cell viability and proliferation of two model breast cancer cell lines with different characteristics. In addition to the strong reduction in cell viability, two of the fractions showed significant influence on the proliferation rate of the hormone receptor expressing MCF7 and the triple negative MDA-MB231 breast cancer cell lines. No significant effects on the benign MCF10A cell line were observed. We applied a large scale non-targeted approach to purify and identify highly abundant compounds from the active fractions of H. rhodopensis extracts. By the combined NMR/MS approach, myconoside was identified in the fractions and hispidulin 8-C-(6-O-acetyl-2″-O-syringoyl-β-glucopyranoside) was found in one of them. We further performed molecular docking analysis of possible myconoside interactions with several proteins, important for breast cancer proliferation. High probability of binding was established for GLUT1 transporter, estrogen receptor and MYST acetyltransferase. Our results are a good background for future studies on the use of myconoside for targeted breast cancer therapy.

Synthesis and characterization of polyethyleneimine/silk fibroin/gold nanoparticle nanocomposites: Potential application as a gene carrier in breast cancer cell lines

There is a need in advancing the design of non-viral gene carriers, thus herein using the pulsed laser ablation in liquid (PLAL) technique, polyethyleneimine-capped gold nanoparticles (PEI-AuNPs) were synthesized and then combined with Bombyx mori silk fibroin (SF) to form the nanocomposites (PEI-SF-AuNPs). After the characterization analyses were carried out, PEI-AuNPs and PEI-SF-AuNPs were tested for their in vitro biocompatibility in MCF-7 and MDA-MB231 breast cancer cells. Finally, the transfection capability of the selected group was observed. PEI capping enabled the cationic modification of the AuNP surface and SF reduced the surface charge (from 35 to 4 mV). PEI-AuNPs were highly monodispersed in shape and size (8–9 nm). The nanoparticle group synthesized in 5% (w/v) PEI concentration (PEI-AuNP5) had increased cytotoxicity as compared to the group synthesized in 1% (w/v) PEI concentration (PEI-AuNP1), but the conjugation of SF with PEI-AuNPs alleviated this cytotoxic tendency significantly. The group (PEI-AuNP1) with the most negligible cytotoxicity proved to be successful in the transfection of siRNA analog, i.e., siGLO green transfection indicator. Overall, the PEI-AuNP1 nanocomposites could be suggested as potent siRNA carriers due to the above beneficial properties in gene-based breast cancer therapies.

The synergistic effect of chimeras consisting of N-terminal smac and modified KLA peptides in inducing apoptosis in breast cancer cell lines

Drug resistance is one of the most important obstacles in effective cancer therapy triggered through various mechanisms. One of these mechanisms is caused by the upregulation of Inhibitor of Apoptosis Proteins (IAPs). IAPs, inhibit apoptosis through direct and/or indirect caspase inhibition, which themselves are antagonized by an endogenous protein called Second Mitochondrial-derived Activator of Caspases, Smac/Diablo, mediated by the presence of a tetrapeptide IAP binding motif at its N-terminus. Accordingly, Smac-based peptides are under intense investigation as anti-cancer drugs and have reached Phase 2 clinical trials, although, Smac based peptides or mimetics alone have not been effective as anti-cancer agents. On the other hand, KLA peptide has shown major toxicity against cancer cells through the induction of apoptosis. Consequently, we designed an anti-cancer chimera by fusing an octa-peptide from the N-terminus of mature Smac protein to a modified proapoptotic KLA peptide (KLAKLCKKLAKLCK) to be called Smac-KLA. This chimera, therefore, possesses both proapoptotic and anti-IAP activities. In addition, we dimerized this chimera via intermolecular disulfide bonds in order to enhance their cellular permeability. Both the Smac-KLA monomeric and dimeric peptides exhibited cytotoxic activity against both MCF-7 and MDA-MB231 breast cancer cell lines at low micromolar concentrations. Importantly, the dimerization of the chimeras enhanced their potency 2-4- fold due to higher cellular uptake.

Abstract P2-16-07: Overexpression of the alpha subunit of the epithelial sodium channel in MDAMB231 breast cancer cells reduces cell migration and proliferation

Abstract Breast cancer is the most common cancer diagnosed in women worldwide and leads to 600,000+ deaths annually. The vast majority of breast cancer-related deaths are attributed to metastasis from the primary site in the breast to visceral organs or the brain. Therefore, understanding how these cells achieve metastasis is vital. Ion channels, such as the epithelial sodium channel (ENaC), are emerging as new targets for cancer research due to their role in regulating cell functions such as the process that allows cancer cells to undergo phenotypic changes necessary for metastasis. Ion channel dysregulation may be crucial in cancer development due to the ion channels’ potential role in controlling cancer cell characteristics such as migration and proliferation. There is limited research investigating the role ENaC may have in breast cancer. We have shown that more migratory, mesenchymal breast cancer cell lines have reduced mRNA and protein expression of ENaC compared to more epithelial breast cancer cell lines. Importantly, higher expression levels of the pore-forming alpha-ENaC subunit is correlated with an increased breast cancer survival in patients (n=1705) included in the SCAN-B data set. Bioinformatic analysis, using the SCAN-B data set, showed an increase in the expression of alpha-ENaC mRNA correlated with lower expression levels of migration and proliferation markers, suggesting ENaC has a role in breast cancer cell proliferation and migration. Therefore, this research examines the influence of stably overexpressing the pore-forming subunit of ENaC, alpha-ENaC, in breast cancer cells on their cell migration and proliferation ability. We hypothesised that increasing the expression of ENaC will restore the cells to a more epithelial state, thus reducing cell migration and proliferation. MDAMB231 breast cancer cells were engineered via a stable transfection to overexpress alpha-ENaC or to express an empty vector control. Several clones were isolated and expanded and using RTqPCR, alpha-ENaC mRNA overexpression was confirmed to consistently have 200-fold increased mRNA expression compared to control cells (n=9, p=0.0006). An increase in alpha-ENaC protein expression was also confirmed via western blotting. Using an EdU assay the alpha-ENaC overexpressing cells were shown to have a significant reduction in proliferation compared to the control cell line (n=3, p=0.0048). The alpha-ENaC overexpressing cells showed reduced migratory ability when examined in two established migration assays. In scratch wound assays, the alpha-ENaC overexpressing cells had a significant reduction in cell migration at 24 hours post scratch (n=4, p=0.0001). In Boyden chamber assays, the number of alpha-ENaC-overexpressing cells that migrated through the membrane was significantly reduced compared to the control cell line (n=4, p=0.02). Our results suggest that increased sodium entry into the cell through ENaC has a role in preventing the development of metastatic breast cancer cells, and highlights ENaC as a potential target for future breast cancer therapies. Citation Format: Sarah McQueen, Adam Ware, Heather Cunliffe, Fiona McDonald. Overexpression of the alpha subunit of the epithelial sodium channel in MDAMB231 breast cancer cells reduces cell migration and proliferation [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P2-16-07.

Withania somnifera Alter BCL2/Bax signaling and trigger apoptosis of MCF-7 and MDA-MB231 breast cancer cells exposed to γ-radiation.

Treatment strategies encompass synchronization of more than one therapy with specific dependence on zeroing side effects of natural products that might represent a niche in the continuous struggle against cancer. Thus, this study aimed at assessing the role of Withania somnifera; WS (Ashwagandha) in forcing MCF7 or MDA-MB 231 irradiated breast cancer cells to outweigh the route of programmed cell death. We check to what extent SIRT1-BCL2/Bax signaling pathway was interrelated to form apoptotic cancer cells. MDA or MCF7 cells are categorized into four groups: gp1, Control (C): MDA-MB-231 or MCF7 cells not treated with WS or exposed to γ-rays, gp2 (WS): cells challenged with WS for MDA-MB-231 or MCF7 cells respectively, gp3: irradiated (R) MDA-MB-231 or MCF7 cells exposed to γ-rays (4Gy; one shot) and gp4 WS and irradiated (WS + R): cells challenged with WS as in gp2 and exposed to gamma rays as in gp3. The results revealed that, WS established IC50 equivalent to 4897.8μg/ml in MDA-MB-231 cells or equivalent to 3801.9μg/ml in MCF7 cells. The flowcytometric analysis (Annexin V and cell cycle) showed that WS induces apoptosis at pre-G phase and induces cell arrest at G2/M and preG1 phases for MDA-MB-231 and at the preG1 for MCF7 cells. Furthermore, the WS + R group of cells (MDA-MB-231 and MCF7) showed significant increases in the expression of SIRT1, and BCL2 and a decrease in BAX compared with WS or R group. It could be concluded that WS has an anti-proliferative action on MDA-MB-231 and MCF7 cells because of its capability to enhance apoptosis.

Cycloartane triterpenoid from Euphorbia macrostegia modulates ER stress signaling pathways to induce apoptosis in MDA-MB231 and MCF-7 breast cancer cell lines.

Unfolded protein response (UPR) is involved in breast cancer (BC) progression and drug resistance. Many natural products (NPs) could modulate UPR and used for therapeutic purposes. Herein, we aimed to investigate the molecular mechanism of Cycloart-23E-ene-3β, 25-diol (Cycloart-E25), cytotoxicity, as a NP extracted from Euphorbia macrostegia and focused on endoplasmic-reticulum stress (ERS) and UPR signaling pathways. Reactive oxygen species (ROS) were probed by DCFDA fluorescence dye. Apoptosis was assayed by annexin V/propidium iodide (PI), immunoblotting of anti- and proapoptotic, Bcl-2 and Bax proteins, and mitochondrial transmembrane potential (ΔΨm) changes. Thioflavin T (ThT) staining and immunoblotting of UPR signaling components (CHOP, PERK, ATF6, BiP, and XBP1) were recruited for the assessment of ERS. Our results indicated that Cycloart-E25 noticeably increases ROS levels in both MB-231 MDA-MB-231 and MCF-7 cell lines, p>0.05. Flow cytometry assessments revealed an increase in the cell population undergoing apoptosis. Also, the Bax/Bcl-2 ratio increased in a dose-dependent manner following Cycloart-E25 treatment, significantly, p>0.05. Mitochondrial involvement could be deduced by significant decreases in ΔΨm, p>0.05. Cycloart-E25 potently induces protein aggregation and upregulated CHOP, PERK, ATF6, BiP, and XBP1 factors in both MDA-MB-231 MB-231 and MCF-7 cell lines, indicating the involvement of ERS in Cycloart-E25-mediated apoptosis. In conclusion, Cycloart-E25 increased the accumulation of misfolded proteins and upregulated UPR components. Therefore, induction of ERS may be involved in the trigger of apoptosis in BC cell lines. Cycloart-E25 induced apoptosis in breast cancer cell lines through ERS. More assessments are needed to confirm its in vivo anti-tumoral effects.

Non-covalent strategies to functionalize polymeric nanoparticles with NGR peptides for targeting breast cancer

Surface functionalization of nanoparticles (NPs) with tumor-targeting peptides is an emerging approach with a huge potential to translate in the clinic and ameliorate the efficacy of nano-oncologicals. One major challenge is to find straightforward strategies for anchoring peptides on the surface of biodegradable NPs and ensuring their correct exposure and orientation to bind the target receptor. Here, we propose a non-covalent strategy to functionalize polyester aminic NPs based on the formation of either electrostatic or lipophilic interactions between NPs and the peptide modified with an anchoring moiety. We selected an iNGRt peptide containing a CendR motif (CRNGR) targeting neuropilin receptor 1 (NRP-1), which is upregulated in several cancers. iNGRt was linked with either a short poly(glutamic acid) chain (polyE) or a palmitoyl chain (Palm) and used to functionalize the surface of NPs made of a diamine poly(ε-caprolactone). iNGRt-PolyE was adsorbed on preformed cationic NPs through electrostatic interaction, whereas iNGRt-Palm was integrated into the forming NPs through interactions. In both cases, peptides were strongly associated with NPs of ∼100 nm, low polydispersity indexes, and positive zeta potential values. NPs entered MDA-MB231 breast cancer cells overexpressing NRP-1 via receptor-mediated endocytosis and showed a different cell localization depending on the mode of peptide anchoring. When loaded with the lipophilic anticancer drug docetaxel (DTX), NPs functionalized with the iNGRt-Palm variant exerted a time- and dose-dependent cytotoxicity similar to DTX in MDA-MB-231 cells but were less toxic than DTX toward control MRC-5 human fibroblasts, not expressing NRP-1. In a heterotopic mouse model of triple negative breast cancer, iNGRt-Palm NPs were tolerated better than free DTX and demonstrated superior anticancer activity and survival compared to both free DTX and NPs without peptide functionalization. We foresee that the functionalization strategy with palmitoylated peptides proposed here can be extended to other biodegradable NPs and peptide sequences designed for therapeutic or targeting purposes.

Another Brick to Confirm the Efficacy of Rigosertib as Anticancer Agent.

Rigosertib is a small molecule in preclinical development that, due to its characteristics as a dual PLK1 and PI3K inhibitor, is particularly effective in counteracting the advance of different types of tumors. In this work, we evaluated the efficacy of Rigosertib and the expression of p53 in five different human tumor cell lines in vitro, A549 (lung adenocarcinoma), MCF-7 and MDA-MB231 (breast cancer cells), RPMI 8226 (multiple myeloma), and U87-MG (glioblastoma). We demonstrated that in all cell lines, the effect was dose- and time-dependent, but A549 cells were the most sensible to the treatment while higher concentrations were required for the most resistant cell line U87-MG. Moreover, the highest and lowest p53 levels have been observed, respectively, in A459 and U87-MG cells. The alterations in the cell cycle and in cell-cycle-related proteins were observed in A549 at lower concentrations than U87-MG. In conclusion, with this article we have demonstrated that Rigosertib has different efficacy depending on the cell line considered and that it could be a potential antineoplastic agent against lung cancer in humans.

Comparison of the cytotoxic effect of Embelin with tamoxifen and docetaxel on human breast cancer MCF-7 and MDA MB-231 cell proliferation

Comparison of the cytotoxic effect of Embelin with tamoxifen and docetaxel on human breast cancer MCF-7 and MDA MB-231 cell proliferation

Reinvestigation of Passerini and Ugi scaffolds as multistep apoptotic inducers via dual modulation of caspase 3/7 and P53-MDM2 signaling for halting breast cancer.

Selective induction of breast cancer apoptosis is viewed as the mainstay of various ongoing oncology drug discovery programs. Passerini scaffolds have been recently exploited as selective apoptosis inducers via a caspase 3/7 dependent pathway. Herein, the optimized Passerini caspase activators were manipulated to synergistically induce P53-dependent apoptosis via modulating the closely related P53-MDM2 signaling axis. The adopted design rationale and synthetic routes relied on mimicking the general thematic features of lead MDM2 inhibitors incorporating multiple aromatic rings. Accordingly, the cyclization of representative Passerini derivatives and related Ugi compounds into the corresponding diphenylimidazolidine and spiro derivative was performed, resembling the nutlin-based and spiro MDM-2 inhibitors, respectively. The study was also extended to explore the apoptotic induction capacity of the scaffold after simplification and modifications. MTT assay on MCF-7 and MDA-MB231 breast cancer cells compared to normal fibroblasts (WI-38) revealed their promising cytotoxic activities. The flexible Ugi derivatives 3 and 4, cyclic analog 8, Passerini adduct 12, and the thiosemicarbazide derivative 17 were identified as the study hits regarding cytotoxic potency and selectivity, being over 10-folds more potent (IC50 = 0.065-0.096 μM) and safer (SI = 4.4-18.7) than doxorubicin (IC50 = 0.478 μM, SI = 0.569) on MCF-7 cells. They promoted apoptosis induction via caspase 3/7 activation (3.1-4.1 folds) and P53 induction (up to 4 folds). Further apoptosis studies revealed that these compounds enhanced gene expression of BAX by 2 folds and suppressed Bcl-2 expression by 4.29-7.75 folds in the treated MCF-7 cells. Docking simulations displayed their plausible binding modes with the molecular targets and highlighted their structural determinants of activities for further optimization studies. Finally, in silico prediction of the entire library was computationally performed, showing that most of them could be envisioned as drug-like candidates.

Glucose Enhances Pro-Tumorigenic Functions of Mammary Adipose-Derived Mesenchymal Stromal/Stem Cells on Breast Cancer Cell Lines

Adiposity and diabetes affect breast cancer (BC) progression. We addressed whether glucose may affect the interaction between mammary adipose tissue-derived mesenchymal stromal/stem cells (MAT-MSCs) and BC cells. Two-dimensional co-cultures and spheroids were established in 25 mM or 5.5 mM glucose (High Glucose-HG or Low Glucose-LG) by using MAT-MSCs and MCF7 or MDA-MB231 BC cells. Gene expression was measured by qPCR, while protein levels were measured by cytofluorimetry and ELISA. CD44high/CD24low BC stem-like sub-population was quantified by cytofluorimetry. An in vivo zebrafish model was assessed by injecting spheroid-derived labeled cells. MAT-MSCs co-cultured with BC cells showed an inflammatory/senescent phenotype with increased abundance of IL-6, IL-8, VEGF and p16INK4a, accompanied by altered levels of CDKN2A and LMNB1. BC cells reduced multipotency and increased fibrotic features modulating OCT4, SOX2, NANOG, αSMA and FAP in MAT-MSCs. Of note, these co-culture-mediated changes in MAT-MSCs were partially reverted in LG. Only in HG, MAT-MSCs increased CD44high/CD24low MCF7 sub-population and promoted their ability to form mammospheres. Injection in zebrafish embryos of HG spheroid-derived MCF7 and MAT-MSCs was followed by a significant cellular migration and caudal dissemination. Thus, MAT-MSCs enhance the aggressiveness of BC cells in a HG environment.

Lysinated Multiwalled Carbon Nanotubes with Carbohydrate Ligands as an Effective Nanocarrier for Targeted Doxorubicin Delivery to Breast Cancer Cells.

Multiwalled carbon nanotubes (MWCNTs) are elongated, hollow cylindrical nanotubes made of sp2 carbon. MWCNTs have attracted significant attention in the area of drug delivery due to their high drug-loading capacity and large surface area. Furthermore, they can be linked to bioactive ligands molecules via covalent and noncovalent bonds that allow for the targeted delivery of anticancer drugs such as doxorubicin. The majority of methodologies reported for the functionalization of MWCNTs for drug delivery are quite complex and use expensive linkers and ligands. In the present study, we report a simple, cost-effective approach for functionalizing MWCNTs with the carbohydrate ligands, galactose (GA), mannose (MA) and lactose (LA), using lysine as a linker. The doxorubicin (Dox)-loaded functionalized MWCNTs were characterized using FT-IR, NMR, Raman, XRD and FE-SEM. The drug-loaded MWCNTs were evaluated for drug loading, drug release and cell toxicity in vitro, in breast cancer cells. The results indicated that the carbohydrate-modified lysinated MWCNTs had greater Dox loading capacity, compared to carboxylated MWCNTs (COOHMWCNTs) and lysinated MWCNTs (LyMWCNTs). In vitro drug release experiments indicated that the carbohydrate functionalized LyMWCNTs had higher Dox release at pH 5.0, compared to the physiological pH of 7.4, over 120 h, indicating that they are suitable candidates for targeting the tumor microenvironment as a result of their sustained release profile of Dox. Doxorubicin-loaded galactosylated MWCNTs (Dox-GAMWCNTs) and doxorubicin loaded mannosylated MWCNTs (Dox-MAMWCNTs) had greater anticancer efficacy and cellular uptake, compared to doxorubicin-loaded lactosylated MWCNTs (Dox-LAMWCNTs) and pure Dox, in MDA-MB231 and MCF7 breast cancer cells. However, neither the ligand conjugated multiwall blank carbon nanotubes (GAMWCNTs, MAMWCNTs and LAMWCNTs) nor the lysinated multiwalled blank carbon nanotubes produced significant toxicity in the normal cells. Our results suggest that sugar-tethered multiwalled carbon nanotubes, especially the galactosylated (Dox-GAMWCNTs) and mannosylated (Dox-MAMWCNTs) formulations, may be used to improve the targeted delivery of anticancer drugs to breast cancer cells.

2-Difluoromethoxy-Substituted Estratriene Sulfamates: Synthesis, Antiproliferative SAR, Antitubulin Activity, and Steroid Sulfatase Inhibition.

2-Difluoromethoxyestratriene derivatives were designed to improve potency and in vivo stability of the drug candidate 2-methoxyestradiol (2ME2). Compound evaluation in vitro against the proliferation of MCF-7 and MDA MB-231 breast cancer cells, as inhibitors of tubulin polymerisation and also steroid sulfatase (STS) both in cell lysates and in whole cells, showed promising activities. In antiproliferative assays 2-difluoromethoxyestradiol was less potent than 2ME2, but its sulfamates were often more potent than their corresponding non-fluorinated analogues. The fluorinated bis-sulfamate is a promising antiproliferative agent in MCF-7 cells (GI50 0.28 μM) vs the known 2-methoxyestradiol-3,17-O,O-bissulfamate (STX140, GI50 0.52 μM), confirming the utility of our approach. Compounds were also evaluated in the NCI 60-cell line panel and the fluorinated bis-sulfamate derivative displayed very good overall activities with a sub-micromolar average GI50 . It was a very potent STS inhibitor in whole JEG-3 cells (IC50 3.7 nM) similar to STX140 (4.2 nM) and additionally interferes with tubulin assembly in vitro and colchicine binding to tubulin. An X-ray study of 2-difluoromethoxy-3-benzyloxyestra-1,3,5(10)-trien-17-one examined conformational aspects of the fluorinated substituent. The known related derivative 2-difluoromethyl-3-sulfamoyloxyestrone was evaluated for STS inhibition in whole JEG-3 cells and showed an excellent IC50 of 55 pM.

M1 macrophages evoke an increase in polymeric immunoglobulin receptor (PIGR) expression in MDA-MB468 breast cancer cells through secretion of interleukin-1β

High expression of polymeric immunoglobulin receptor (PIGR) in breast cancer is associated with increased 5-year survival rate. However, the factors influencing PIGR expression in breast cancer have not been elucidated. The aim of this study was to determine the role of macrophages and cytokines affecting expression of PIGR in two breast cancer cell lines. M1, M2 macrophage conditioned media (CM) and recombinant human cytokines were used to determine factors which increased PIGR expression in MCF7 (HTB-22) and MDA-MB468 (HTB-132) breast cancer cell lines. The level of PIGR expression in the cells and PIGR secretory component were evaluated by real-time quantitative polymerase chain reaction and Western blotting. M1 macrophage CM induced a dose-dependent increase in PIGR mRNA expression in MDA-MB468 cells, up to 20-fold. The level of PIGR expression in MCF7 cells was very low and not affected by M1 and M2 CM. Interferon gamma (IFN-γ) and interleukin (IL)-1β also increased PIGR expression in MDA-MB468 and MCF7 cells. However, IL-1β was demonstrated to increase in M1 macrophages, while IFN-γ was not. The role of IL-1β secreted from M1 macrophages in increasing expression of PIGR was confirmed by IL-1 receptor blockade, indicating that IL-1β was the major M1 macrophage-derived cytokine that enhanced PIGR expression. Elevated PIGR expression in breast cancer in vivo may reflect the polarization state of tumor-associated immune cells.

Antitumor Potential of Sericite Treatment Mediated by Cell Cycle Arrest in Triple-Negative MDA-MB231 Breast Cancer Cells.

Breast cancer is the most common cancer and the leading cause of cancer-related mortality among females worldwide. Triple-negative breast cancer (TNBC) accounts for about 10–15% of all breast cancers and is usually more aggressive and has a poorer prognosis. Sericite has been known to have antitumor and immune-stimulatory effects. Although the chemopreventive potential of sericite has been demonstrated in other cancers, its molecular pathways in TNBC still require investigation. Thus, in the present study, the antitumor mechanism of sericite against MDA-MB231 breast cancer cells was examined in vitro and in an in vivo xenograft mouse model. Sericite treatment reduced cell proliferation and cell proliferation marker proliferating cell nuclear antigen (PCNA) in MDA-MB231 cells. It also decreased the total cell number and arrested cells in the G0/G1 phase of the cell cycle with an increase in the phosphorylation of P53 and upregulation of cell cycle regulatory proteins P21 and P16. In addition, sericite treatment also induced apoptosis signaling, which was evident by the upregulation of apoptotic protein markers cleaved caspases 3 and 9. A reduction in reactive oxygen species (ROS), NADPH oxidase 4 (NOX4), p22phox, and heat shock proteins (HSPs) was also observed. Similar results were obtained in vivo with significantly reduced tumor volume in sericite-administered mice. Collectively, these findings suggest that sericite has antitumor potential based on its property to induce cell cycle arrest and apoptotic cell death and therefore could serve as a potential therapeutic agent and crucial candidate in anticancer drug development for TNBC.

Suppression of OCT-1 in Metastatic Breast Cancer Cells Reduces Tumor Metastatic Potential, Hypoxia Resistance, and Drug Resistance.

OCT-1/POU2F1 is a ubiquitously expressed transcription factor. Its expression starts at the earliest stage of embryonic development. OCT-1 controls genes involved in the regulation of differentiation, proliferation, cell metabolism, and aging. High levels of OCT-1 transcription factor in tumor cells correlate with tumor malignancy and resistance to antitumor therapy. Here, we report that suppression of OCT-1 in breast cancer cells reduces their metastatic potential and drug resistance. OCT-1 knockdown in the MDA-MB231 breast cancer cells leads to a fivefold decrease (p < 0.01) in cell migration rates in the Boyden chamber. A decrease in the transcription levels of human invasion signature (HIS) genes (ARHGDIB, CAPZA2, PHACTR2, CDC42, XRCC5, and CAV1) has been also demonstrated by real-time PCR, with high expression of these genes being a hallmark of actively metastasizing breast cancer cells. Transcriptional activity of ATF6 response elements is significantly reduced in the cell lines with decreased OCT-1 expression, which results in lower levels of adaptive EPR stress response. OCT-1 knockdown more than two times increases the MDA-MB231 cell death rate in hypoxia and significantly increases the doxorubicin or docetaxel-treated MDA-MB231 cell death rate. Our findings indicate that OCT-1 may be an important therapeutic target and its selective inhibition may have significant therapeutic effects and may improve prognosis in breast cancer patients.