Hyaluronic Acid-Targeted Stimuli-Sensitive Nanomicelles Co-Encapsulating Paclitaxel and Ritonavir to Overcome Multi-Drug Resistance in Metastatic Breast Cancer and Triple-Negative Breast Cancer Cells.

Active targeting and overcoming multi-drug resistance (MDR) can be some of the important attributes of targeted therapy for metastatic breast cancer (MBC) and triple-negative breast cancer (TNBC) treatment. In this study, we constructed a hyaluronic acid (HA)-decorated mixed nanomicelles-encapsulating chemotherapeutic agent paclitaxel (PTX) and P-glycoprotein inhibitor ritonavir (RTV). HA was conjugated to poly (lactide) co-(glycolide) (PLGA) polymer by disulfide bonds (HA-ss-PLGA). HA is a natural ligand for CD44 receptors overexpressed in breast cancer cells. Disulfide bonds undergo rapid reduction in the presence of glutathione, present in breast cancer cells. The addition of RTV can inhibit the P-gp and CYP3A4-mediated metabolism of PTX, thus aiding in reversing MDR and sensitizing the cells toward PTX. An in vitro uptake and cytotoxicity study in MBC MCF-7 and TNBC MDA-MB-231 cell lines demonstrated the effective uptake of the nanomicelles and drug PTX compared to non-neoplastic breast epithelium MCF-12A cells. Interestingly, in vitro potency determination showed a reduction in mitochondrial membrane potential and reactive oxygen species in breast cancer cell lines, indicating effective apoptosis of cancer cells. Thus, stimuli-sensitive nanomicelles along with HA targeting and RTV addition can effectively serve as a chemotherapeutic drug delivery agent for MBC and TNBC.

Berberine-induced nucleolar stress response in a human breast cancer cell line.

We investigated the novel molecular mechanisms of the antitumor effect of berberine. In this study, two different human cell lines (breast cancer MCF7 cells and non-tumorigenic epithelial MCF12A cells) were treated with various concentrations of berberine. Treatment with 1 and 10 µM berberine inhibited proliferation with G0/G1 cell cycle arrest in both cell lines, and treatment with 100 µM berberine triggered a marked level of cell death in MCF7 cells but not in MCF12A cells. Berberine increased the level of p53 protein and of its target p21 both time- and dose-dependently in MCF7 cells. At any concentration of berberine, immediate uptake (within 15 min) followed by predominantly mitochondrial accumulation were observed by confocal microscopy in both cell lines. At high concentrations (10 or 100 µM), accumulation in the nucleolus became prominent after the transition to the nucleoplasm, especially remarkable in MCF7 cells. Therefore, we evaluated the possibility of berberine-induced nucleolar stress and observed the disappearance of ribosomal protein (RP)L5 from the nucleolus and accumulation of p53 protein in the nucleus after treatment with 10 or 100 µM berberine in MCF7 cells. We also detected the accumulation of RPL5 and RPL11 in the nucleoplasm fraction where they bind to Mdm2. Moreover, downregulation of RPL5 inhibited berberine-driven induction of p53 and p21 and cell death in MCF7 cells. Whereas, in MCF12A cells, down-regulation of RPL5 had little effect on the growth inhibitory effect of high concentration of berberine. These results indicated that cell growth inhibition and cell death induced by higher doses (>10 µM) of berberine in MCF7 cells were due to the upregulation of p53 under the nucleolar stress response caused by a significant accumulation of berberine in the nucleoli.

Modulation of VEGF Expression and Oxidative Stress Response by Iodine Deficiency in Irradiated Cancerous and Non-Cancerous Breast Cells.

Breast cancer remains a major concern and its physiopathology is influenced by iodine deficiency (ID) and radiation exposure. Since radiation and ID can separately induce oxidative stress (OS) and microvascular responses in breast, their combination could additively increase these responses. Therefore, ID was induced in MCF7 and MCF12A breast cell lines by medium change. Cells were then X-irradiated with doses of 0.05, 0.1, or 3 Gy. In MCF12A cells, both ID and radiation (0.1 and 3 Gy) increased OS and vascular endothelial growth factor (VEGF) expression, with an additive effect when the highest dose was combined with ID. However, in MCF7 cells no additive effect was observed. VEGF mRNA up-regulation was reactive oxygen species (ROS)-dependent, involving radiation-induced mitochondrial ROS. Results on total VEGF mRNA hold true for the pro-angiogenic isoform VEGF165 mRNA, but the treatments did not modulate the anti-angiogenic isoform VEGF165b. Radiation-induced antioxidant response was differentially regulated upon ID in both cell lines. Thus, radiation response is modulated according to iodine status and cell type and can lead to additive effects on ROS and VEGF. As these are often involved in cancer initiation and progression, we believe that iodine status should be taken into account in radiation prevention policies.

Telomerase Inhibitor TMPyP4 Alters Adhesion and Migration of Breast-Cancer Cells MCF7 and MDA-MB-231.

Human telomeres were one of the first discovered and characterized sequences forming quadruplex structures. Association of these structures with oncogenic and tumor suppressor proteins suggests their important role in cancer development and therapy efficacy. Since cationic porphyrin TMPyP4 is known as G-quadruplex stabilizer and telomerase inhibitor, the aim of the study was to analyze the anticancer properties of this compound in two different human breast-cancer MCF7 and MDA-MB-231 cell lines. The cytotoxicity of TMPyP4 alone or in combination with doxorubicin was measured by MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromid) and clonogenic assays, and the cell-cycle alterations were analyzed by flow cytometry. Telomerase expression and activity were evaluated using qPCR and telomeric repeat amplification protocol (TRAP) assays, respectively. The contribution of G-quadruplex inhibitor to protein pathways engaged in cell survival, DNA repair, adhesion, and migration was performed using immunodetection. Scratch assay and functional assessment of migration and cell adhesion were also performed. Consequently, it was revealed that in the short term, TMPyP4 neither revealed cytotoxic effect nor sensitized MCF7 and MDA-MB-231 to doxorubicin, but altered breast-cancer cell adhesion and migration. It suggests that TMPyP4 might substantially contribute to a significant decrease in cancer cell dissemination and, consequently, cancer cell survival reduction. Importantly, this effect might not be associated with telomeres or telomerase.

Zeolite X from coal fly ash inhibits proliferation of human breast cancer cell lines (MCF-7) via induction of S phase arrest and apoptosis.

In this study, zeolite X synthesised from coal fly ash (CFA) was examined for its anti-proliferative effects on human breast cancer MCF-7 cells by in vitro studies and allied probable molecular mechanism were also assessed. MTT assay exposed that zeolite X showed a concentration-dependent inhibitory result on the proliferation of MCF-7 cells and caused early apoptotic death and does not induce cytotoxicity in non-cancerous cells (MCF-12A). Flow cytometric study specified the accrual of cells at S phase suggest induction of apoptosis which was avowed through fluorescence and confocal microscopy following annexin V-FITC/propidium iodide (PI). MCF-7 cells treated by 10, 15 and 20 µg/ml concentrations of zeolite X showed internucleosomal DNA fragments in ladder form, thereby indicates cell death is associated with apoptosis. Mechanistically, our data support the induction of apoptosis through the activation of mitochondrial dependent pathway as indicated by an up-regulation of Bax and downregulation of Bcl-2 ratio, the expulsion of cytochrome c from the mitochondria to the cytosol and cleavage of pro-caspase-3 into activation of caspase-3 in MCF-7 cells. Based on these outcomes zeolite X induced early apoptosis and strongly provided experimental evidence for the usage of zeolite X as an essential therapeutic agent in the prevention and therapy of human breast cancer.

Serotonin suppresses ß-casein expression via PTP1B activation in human mammary epithelial cells.

Serotonin (5-hydroxytriptamine, 5-HT) has an important role in milk volume homeostasis within the mammary gland during lactation. We have previously shown that the expression of ß-casein, a differentiation marker in mammary epithelial cells, is suppressed via 5-HT-mediated inhibition of signal transduction and activator of transcription 5 (STAT5) phosphorylation in the human mammary epithelial MCF-12A cell line. In addition, the reduction of ß-casein in turn was associated with 5-HT7 receptor expression in the cells. The objective of this study was to determine the mechanisms underlying the 5-HT-mediated suppression of ß-casein and STAT5 phosphorylation. The ß-casein level and phosphorylated STAT5 (pSTAT5)/STAT5 ratio in the cells co-treated with 5-HT and a protein kinase A (PKA) inhibitor (KT5720) were significantly higher than those of cells treated with 5-HT alone. Exposure to 100 µM db-cAMP for 6 h significantly decreased the protein levels of ß-casein and pSTAT5 and the pSTAT5/STAT5 ratio, and significantly increased PTP1B protein levels. In the cells co-treated with 5-HT and an extracellular signal-regulated kinase1/2 (ERK) inhibitor (FR180294) or Akt inhibitor (124005), the ß-casein level and pSTAT5/STAT5 ratio were equal to those of cells treated with 5-HT alone. Treatment with 5-HT significantly induced PTP1B protein levels, whereas its increase was inhibited by KT5720. In addition, the PTP1B inhibitor sc-222227 increased the expression levels of ß-casein and the pSTAT5/STAT5 ratio. Our observations indicate that PTP1B directly regulates STAT5 phosphorylation and that its activation via the cAMP/PKA pathway downstream of the 5-HT7 receptor is involved in the suppression of ß-casein expression in MCF-12A cells.

Phytochemicals from Pterocarpus angolensis DC and Their Cytotoxic Activities against Breast Cancer Cells.

Pterocarpus anglonesis DC is an indigenous medicinal plant belonging to the Pterocarpus genus of the Fabaceae family. It is used to treat stomach problems, headaches, mouth ulcers, malaria, blackwater fever, gonorrhea, ringworm, diarrhea, heavy menstruation, and breast milk stimulation. Column chromatography of the stem bark extracts resulted in the isolation of eight compounds, which included friedelan-3-one (1), 3α-hydroxyfriedel-2-one (2), 3-hydroxyfriedel-3-en-2-one (3), lup-20(29)-en-3-ol (4), Stigmasta-5-22-dien-3-ol (5), 4-O-methylangolensis (6), (3ß)-3-acetoxyolean-12-en-28-oic acid (7), and tetradecyl (E)-ferulate (8). The structures were established based on NMR, IR, and MS spectroscopic analyses. Triple-negative breast cancer (HCC70), hormone receptor-positive breast cancer (MCF-7), and non-cancerous mammary epithelial cell lines (MCF-12A) were used to test the compounds' cytotoxicity. Overall, the compounds showed either no toxicity or very low toxicity to all three cell lines tested, except for the moderate toxicity displayed by lupeol (4) towards the non-cancerous MCF-12A cells, with an IC50 value of 36.60 µM. Compound (3ß)-3-acetoxyolean-12-en-28-oic acid (7) was more toxic towards hormone-responsive (MCF-7) breast cancer cells than either triple-negative breast cancer (HCC70) or non-cancerous breast epithelial (MCF-12A) cells (IC50 values of 83.06 vs. 146.80 and 143.00 µM, respectively).

In vitro cytotoxic effect of stigmasterol derivatives against breast cancer cells.

BACKGROUND: Stigmasterol is an unsaturated phytosterol that belong to the class of tetracyclic steroids abundant in Rhoicissus tridentata. Stigmasterol is an important constituent since it has shown impressive pharmacological effects such as anti-osteoarthritis, anticancer, anti-diabetic, anti-inflammatory, antiparasitic, immunomodulatory, antifungal, antioxidant, antibacterial, and neuroprotective activities. Furthermore, due to the presence of π system and hydroxyl group, stigmasterol is readily derivatized through substitution and addition reactions, allowing for the synthesis of a wide variety of stigmasterol derivatives. METHODS: Stigmasterol (1) isolated from Rhoicissus tridentata was used as starting material to yield eight bio-active derivatives (2-9) through acetylation, epoxidation, epoxide ring opening, oxidation, and dihydroxylation reactions. The structures of all the compounds were established using spectroscopic techniques, NMR, IR, MS, and melting points. The synthesized stigmasterol derivatives were screened for cytotoxicity against the hormone receptor-positive breast cancer (MCF-7), triple-negative breast cancer (HCC70), and non-tumorigenic mammary epithelial (MCF-12 A) cell lines using the resazurin assay. RESULTS: Eight stigmasterol derivatives were successfully synthesized namely; Stigmasterol acetate (2), Stigmasta-5,22-dien-3,7-dione (3), 5,6-Epoxystigmast-22-en-3ß-ol (4), 5,6-Epoxystigmasta-3ß,22,23-triol (5), Stigmastane-3ß,5,6,22,23-pentol (6), Stigmasta-5-en-3,7-dion-22,23-diol (7), Stigmasta-3,7-dion-5,6,22,23-ol (8) and Stigmast-5-ene-3ß,22,23-triol (9). This is the first report of Stigmasta-5-en-3,7-dion-22,23-diol (7) and Stigmasta-3,7-dion-5,6,22,23-ol (8). The synthesized stigmasterol analogues showed improved cytotoxic activity overall compared to the stigmasterol (1), which was not toxic to the three cell lines tested (EC50 ˃ 250 µM). In particular, 5,6-Epoxystigmast-22-en-3ß-ol (4) and stigmast-5-ene-3ß,22,23-triol (9) displayed improved cytotoxicity and selectivity against MCF-7 breast cancer cells (EC50 values of 21.92 and 22.94 µM, respectively), while stigmastane-3ß,5,6,22,23-pentol (6) showed improved cytotoxic activity against the HCC70 cell line (EC50: 16.82 µM). CONCLUSION: Natural products from Rhoicissus tridentata and their derivatives exhibit a wide range of pharmacological activities, including anticancer activity. The results obtained from this study indicate that molecular modification of stigmasterol functional groups can generate structural analogues with improved anticancer activity. Stigmasterol derivatives have potential as candidates for novel anticancer drugs.

Comparison of the Toxicological Effects of Pesticides in Non-Tumorigenic MCF-12A and Tumorigenic MCF-7 Human Breast Cells.

Humans are exposed to residues of organophosphate and neonicotinoid pesticides, commonly used in agriculture. Children are particularly vulnerable and, among possible adverse outcomes, the increased incidence of premature mammary gland development (thelarche) has raised concern. We evaluated the toxicological effects of chlorpyrifos (CPF), imidacloprid (IMI) and glyphosate (GLY) at exposure concentrations occurring in children on the tumorigenic MCF-7 and non-tumorigenic MCF-12A breast cell lines, as representative of the target organ model, assessing cytotoxicity, apoptosis, necrosis, intracellular reactive oxygen species (ROS) and ATP levels, 17ß-estradiol secretion and gene expression of nuclear receptors involved in mammary gland development. The pesticides decreased cell vitality in MCF-7 and cell proliferation in MCF-12A cells. ATP levels were decreased in MCF-7 cells by pesticides and apoptosis was increased in MCF-12A cells only by GLY (2.3 nM). ROS production was decreased by pesticides in both cell lines, except IMI (1.6 nM) in MCF-7 cells. Endocrine disrupting activity was highlighted by induction of 17ß-estradiol secretion and modulation of the gene expression of estrogen alpha and beta, progesterone, androgen, and aryl hydrocarbon receptors in both cell lines. The use of MCF-7 and MCF-12A cells highlighted dissimilar modes of action of each pesticide at low human relevant concentrations.

Comparison of Anticancer Activity of Dorycnium pentaphyllum Extract on MCF-7 and MCF-12A Cell Line: Correlation with Invasion and Adhesion.

Dorycnium pentaphyllum subsp. haussknechtii is an important medicinal plant in several countries, including Turkey. This study aimed to evaluate the cytotoxicity of a crude extract of D. pentaphyllum subsp. haussknechtii against different breast cell lines to determine invasion, adhesion, and lipid peroxidation. The cytotoxic effects on MCF-7 breast cancer and MCF-12A as the immortalized cell line were examined by the XTT assay. Invasion and adhesion studies were performed according to the manufacturer's kit procedure to IC50 values for 48 h. Lipid peroxidation was measured in the MCF-7 cell. A bioinformatics analysis was conducted to unravel the mechanism of action underlying antiproliferative effects, as well. According to XTT results, the tested extract showed a time- and a concentration-dependent cytotoxic effect. The most effective concentration was 100.5 µg/mL (48 h), which was selected for biological activities, such as apoptotic activity, invasion, adhesion, and lipid peroxidation assays. The extract caused tumoral cell death, and it did not have a cytotoxic effect on healthy human breast cells. Duplication times and measurement of CI analyses of cells were performed using the real-time cell analysis system xCELLigence. Finally, the bioinformatics analysis indicated the prominent role of quercetin as an extract component exerting a key role in the observed antiproliferative effects. This was supported by the micromolar/submicromolar affinity of quercetin towards proto-oncogene serine/threonine-protein kinase (PIM-1) and hematopoietic cell kinase (HCK), both involved in breast cancer. Altogether, our findings proposed that the extraction of the plant can be an effective strategy to isolate biomolecules with promising cytotoxic effects against breast cancer cells.

Octreotide-Targeted Lcn2 siRNA PEGylated Liposomes as a Treatment for Metastatic Breast Cancer.

Lcn2 overexpression in metastatic breast cancer (MBC) can lead to cancer progression by inducing the epithelial-to-mesenchymal transition and enhancing tumor angiogenesis. In this study, we engineered a PEGylated liposomal system encapsulating lipocalin 2 (Lcn2) small interfering RNA (Lcn2 siRNA) for selective targeting MBC cell line MCF-7 and triple-negative breast cancer cell line MDA-MB-231. The PEGylated liposomes were decorated with octreotide (OCT) peptide. OCT is an octapeptide analog of somatostatin growth hormone, having affinity for somatostatin receptors, overexpressed on breast cancer cells. Optimized OCT-targeted Lcn2 siRNA encapsulated PEGylated liposomes (OCT-Lcn2-Lipo) had a mean size of 152.00 nm, PDI, 0.13, zeta potential 4.10 mV and entrapment and loading efficiencies of 69.5% and 7.8%, respectively. In vitro uptake and intracellular distribution of OCT-Lcn2-Lipo in MCF-7 and MDA-MB-231 and MCF-12A cells demonstrated higher uptake for the OCT-targeted liposomes at 6 h by flow cytometry and confocal microscopy. OCT-Lcn2-lipo could achieve approximately 55-60% silencing of Lcn2 mRNA in MCF-7 and MDA-MB-231 cells. OCT-Lcn2-Lipo also demonstrated in vitro anti-angiogenic effects in MCF-7 and MDA-MB-231 cells by reducing VEGF-A and reducing the endothelial cells (HUVEC) migration levels. This approach may be useful in inhibiting angiogenesis in MBC.

The use of 3D cultures of MCF-10A and MCF-12A cells by high content screening for effect-based analysis of non-genotoxic carcinogens.

The human breast epithelial cell lines MCF-10A and MCF-12A form well-differentiated acinus-like structures when grown in three-dimensional matrigel culture over a period of 20 days. In the present study, both cell lines were tested for their suitability to serve as an effect-based in vitro test system for non-genotoxic carcinogens. A software solution for automated Acinus Detection And Morphological Evaluation (ADAME) was developed to automatically acquire acinus images and to determine morphological parameters such as acinus size, lumen size, and acinus roundness. A number of test compounds were tested for their capacity to affect acinus formation and cellular differentiation. Human epidermal growth factor stimulated acinus growth for both cell lines whereas all-trans retinoic acid inhibited acinus growth. The strong estrogen 17ß-estradiol had no effect on acinus formation of estrogen receptor (ER)-negative MCF-10A cells, but yielded larger MCF-12A (ER-positive) acini. Thus, the parallel use of both cell lines allows the identification of estrogenic properties of a given test compound.

The Effects of Petroselinum Crispum on Estrogen Receptor-positive Benign and Malignant Mammary Cells (MCF12A/MCF7).

BACKGROUND: Phytoestrogens have controversial effects on hormone-dependent tumors. Herein we investigated the effects of parsley root extract (PCE) on DNA synthesis performance, metabolic activity and cytotoxicity in malignant and benign breast cells. MATERIALS AND METHODS: The PCE was prepared and analyzed by mass spectrometry. MCF7 and MCF12A cells were incubated with various concentrations of PCE and analyzed for DNA synthesis performance, metabolic activity and cytotoxicity by BrdU proliferation, MTT and LDH assays, respectively. RESULTS: PCE was found to contain a substantial ratio of lignans. At a concentration range of 0.01 µg/ml-100 µg/ml the LDH assay analysis showed no significant cytotoxicity of PCE in both cell lines. However, at 500 µg/ml PCE's cytotoxicity was well over 70% of total cell population in both cell lines. According to the BrdU proliferation assay analysis, PCE demonstrated significant DNA synthesis inhibition of up to 80% at concentrations of 10, 50, 100 and 500 µg/ml in both cell lines. Based on the MTT assay analysis, only at a concentration of 500 µg/ml, PCE demonstrated a statistically significant inhibition of cellular metabolic activity of 63% in MCF7 and 75% in MCF12A of their respective normal capacity. CONCLUSION: PCE showed antiproliferative effects in MCF7 and MCF12A cells. Further investigation is required to determine whether this effect can be solely attributed to its phytoestrogens.

Effects of Fucoidan and Chemotherapeutic Agent Combinations on Malignant and Non-malignant Breast Cell Lines.

OBJECTIVES: Breast cancer is a leading cause of death among women in both developed and Third World countries. Fucoidan is a natural plant metabolite produced by brown seaweeds with proven anticancer potential. This study determined the cytotoxic, apoptotic and cell cycle effects of fucoidan alone and in combination with first-line anticancer drugs (cisplatin, doxorubicin and taxol) in MCF-7 breast cancer cells and non-malignant MCF-12A breast epithelial cells as control. METHODS: Cytotoxicity was evaluated using the MTT reduction assay. Cell cycle distribution and apoptosis were assessed by flow cytometry using Annexin VFITC/PI and Hoechst 33342 staining, and caspases-3, -7 and -9 activation. RESULTS: Fucoidan alone was significantly more cytotoxic to MCF-7 breast cancer cells compared to the MCF-12A non-cancerous breast epithelial cell line. In MCF-7 cells, the presence of fucoidan caused cell cycle arrest at G1 with accumulation of cells in the sub-G1 phase with the activation of caspases-3,-7 and -9. Furthermore, combination of fucoidan with the standard chemotherapeutic agents-cisplatin, doxorubicin and taxol-significantly enhanced the cytotoxicity of these drugs and accumulation of cells in the G2/M and sub-G1 phases, and induction of apoptosis. No significant differences were observed between fucoidan-treated and untreated MCF-12A cells with respect to cytotoxicity and cell cycle distribution profiles. By contrast, in non-cancerous MCF-12A cells, fucoidan attenuated the toxicity of doxorubicin and cisplatin in combination by increasing their IC50 values. This effect was not demonstrated with the taxol combination. CONCLUSIONS: Fucoidan is an effective antitumor agent, either alone or in combination with cisplatin, doxorubicin and taxol in MCF-7 breast cancer cells. Drug combinations that discriminate between cancerous and non-cancerous cells afford a plausible and viable strategy of attaining therapeutic efficacy and avoiding possible toxicity and side effects. These findings suggest that fucoidan is a promising candidate for cancer combination therapies.

Inhibitory effect of fluvoxamine on ß-casein expression via a serotonin-independent mechanism in human mammary epithelial cells.

Selective serotonin reuptake inhibitors (SSRIs) are widely used as a first-line therapy in postpartum depression. The objective of this study was to determine the mechanism underlying the inhibitory effects of the SSRI, fluvoxamine, on ß-casein expression, an indicator of lactation, in MCF-12A human mammary epithelial cells. Expression levels of serotonin (5-hydroxytryptamine; 5-HT) transporter, an SSRI target protein, and tryptophan hydroxylase 1, a rate-limiting enzyme in 5-HT biosynthesis, were increased in MCF-12A cells by prolactin treatment. Treatment with 1 µM fluvoxamine for 72 h significantly decreased protein levels of ß-casein and phosphorylated signal transducer and activator transcription 5 (pSTAT5). Extracellular 5-HT levels were significantly increased after exposure to 1 µM fluvoxamine, in comparison with those of untreated and vehicle-treated cells; however, extracellular 5-HT had little effect on the decrease in ß-casein expression. Expression of glucose-related protein 78/binding immunoglobulin protein, a regulator of endoplasmic reticulum (ER) stress, was significantly increased after treatment with 1 µM fluvoxamine for 48 h. Exposure to tunicamycin, an inducer of ER stress, also decreased expression of ß-casein and pSTAT5 in a manner similar to fluvoxamine. Our results indicate that fluvoxamine suppresses ß-casein expression in MCF-12A cells via inhibition of STAT5 phosphorylation caused by induction of ER stress. Further studies are required to confirm the effect of fluvoxamine on the function of mammary epithelial cells.