Estrogen Positive Breast Cancer Cells Research Articles

Bioactive properties of six dried Himalayan plum cultivars and the impact of their powders on lipid peroxidation in meat emulsions

Plum fruits are among the richest sources of bioactive compounds and thereby have several therapeutic effects, in addition to being effective replacers of synthetic antioxidants in foods such as meat sausages, which are more prone to lipid oxidation. Plums have a short shelf life and are therefore mostly processed into dry forms. The study included six plum varieties and the effects of drying on their antioxidant and antiproliferative characteristics were examined. Drying resulted in the almost complete degradation of the anthocyanins. During the six months, DPPH, FRAP and ascorbic acid decreased by 11.7 %, 5.9 % and 33 % respectively, in the Krassivica plum cultivar. Compared to fresh cultivars, dried plum cultivars showed greater antiproliferative potential against both cancer cell lines, with dried Krassivica exhibiting the greatest cell proliferation inhibition of 38.63 and 94.1 % against HCT-116 (a colon cancer cell line) and MCF-7 (an estrogen-positive breast cancer cell line), respectively. Evaluation on the effect of different concentrations (2 %, 4 % and 6 %) of plum on lipid oxidation in the meat emulsion showed that with the addition of plum powder there was a significant reduction in the TBARS. A non-significant difference was observed in the TBARS values at the 1st and 3rd months of storage between the emulsion samples containing 6 % Au Rosa plum pulp powder and the sample with BHA. Thus, it was concluded that although drying has a marked influence on the quality of plum fruits, dried plums represent a good source of antioxidants, thereby promoting their use as a functional food.

Affinity for Estrogen Receptor α (ERα) in a <i>trans</i>-Stilbene Derivative Containing a Pyridoxine Fragment

Molecular targets for a promising antitumor agent based on trans-stilbene containing a pyridoxine fragment were identified. The lead compound, (E)-6-(3,4-dimethoxystyryl)-2,2,5,8-tetramethyl-4H-[1,3] dioxino[4,5-c]pyridine, was found to selectively induce apoptosis in MCF-7 breast adenocarcinoma cells overexpressing estrogen receptor, but not in MDA-MB-231 cells negative for estrogen receptor. The mechanism by which the novel trans-stilbene derivative acts as a selective estrogen receptor modulator was analyzed, and the affinity for human estrogen receptor α (ERα) was assessed by fluorescence polarization. Unlike its structural analogs—tamoxifen and raloxifene, the lead compound showed no affinity for ERα and did not form complexes with it. Therefore, it was concluded that the selective action of the pyridoxine-containing derivative of trans-stilbene on estrogen-positive breast cancer cells occurs through an alternative mechanism. The EC 50 values for the displacement of the fluorescent ligand from the ERα active site were 22, 120, and 595 nM for estradiol, raloxifene, and tamoxifen, respectively.

Oxysterols in catfish skin secretions (Arius bilineatus, Val.) exhibit anti-cancer properties

The edible catfish Arius bilineatus, (Valenciennes) elaborates a proteinaceous gel-like material through its epidermis when threatened or injured. Our on-going studies on this gel have shown it to be a complex mixture of several biologically active molecules. Anti-cancer studies on lipid fractions isolated from the gel-like materials showed them to be active against several cancer cell lines. This prompted us to investigate further the lipid composition of the catfish epidermal gel secretions (EGS). Analysis of the lipid fraction of EGS resulted in identification of 12 oxysterols including cholesterol and 2 deoxygenated steroids i.e., 7α-hydroxy cholesterol, 7β-hydroxycholesterol, 5,6 epoxycholesterol, 3β-hydroxycholest-5-ene-7-one and cholesta-3,5-dien-7-one. Progesterone, cholest-3,5-diene, cholesta-2,4-diene, cholest-3,5,6-triol and 4-cholesten-3-one were found as minor components, and were identified through their MS, 1HNMR and FTIR spectral data and were compared with those of the standards. Cholest-3,6-dione, cholesta-4,6-diene-3-one, cholesta-2,4-diene, and cholesta-5,20(22)-dien-3-ol were found only in trace amounts and were identified by GC/MS/MS spectral data. Since cholesterol is the major component of EGS, the identified oxysterols (OS) are presumably cholesterol oxidation products. Many of the identified OS are known important biological molecules that play vital physiological role in the producer and recipient organisms. We report herein the effects of these sterols on three human cancer cell lines in vitro, i.e., K-562 (CML cell line), MDA MB-231 (estrogen positive breast cancer cell line) and MCF-7 (estrogen negative breast cancer cell line). Interestingly significant (p < 0.05) dose differences were observed between tested OS on cell types used. The presence of these sterols in EGS may help explain some aspects of the physiological activities of fraction B (FB) prepared from EGS, such as enhanced wound and diabetic ulcer healing, anti-inflammatory action and cytotoxic activities reported in our previous studies. The anti-proliferative actions of some of these oxysterols especially the cholesterol 3,5,6-triol (#5) as established on selected cancer cell lines in this study support our previous studies and make them candidates for research for human application.

Safe and selective anticancer agents from tetrafluorinated azobenzene-imidazolium ionic liquids: Synthesis, characterization, and cytotoxic effects.

A new series of tetrafluorinated azobenzene-imidazolium salts is reported. The azobenzene and imidazolium moieties were functionalized with long alkyl chains and connected via a methylene spacer of varying lengths (n = 3-12). They were characterized using FTIR and NMR spectroscopy, and elemental microanalysis. The cytotoxic potential of these ionic dimers against neuroblastoma (SHSY-5Y), estrogen-positive breast cancer cells (MCF-7), triple-negative breast cancer cells (MDA-MB-231), cervical cancer cells (HeLa), and human skin fibroblasts (Hs27) was evaluated using the MTT assay. The cytotoxicity of these ionic liquids (ILs) was dependent on the spacer length. A cut-off effect was observed, wherein the cytotoxicity of the ILs was enhanced by increasing the nonpolar, hydrophobic spacer length up to a threshold and the potency was leveled off upon chain elongation. All ILs exhibited selective and remarkable inhibition potentials against HeLa cells in a dose-dependent manner, which was 2-22 times stronger than that of etoposide, a clinical anticancer drug. These ILs were less toxic toward skin fibroblasts as implied by much higher IC50 values. The long-spacer ILs (n = 7-10) were very selective toward HeLa cells. They had a broad safety window with selectivity indices ranging between 5.6 and 11.0. The selectivity of these compounds toward HeLa cells may serve as a new strategy for the design and development of safe and effective chemotherapeutics.

Abstract 3133: Clonal facilitation drives estrogen receptor positive (ER+) breast cancer growth and survival

Abstract Competition between different lineages of cells within a tumor has been included in thinking about cancer evolution and progression, but positive interactions like cooperation have received far less study. We have developed isogenic estrogen positive breast cancer cell lineages sensitive and resistant to CDK4/6 inhibition in order to investigate the mechanisms cell interactions under selective pressure. When these sensitive and resistant lineages are grown in co-culture under ribociclib treatment, sensitive survive and proliferate better than in mono-culture despite the effects of competition. Conditioned media taken from resistant cells grown in monoculture conditions reproduces this advantage, suggesting that secretion of some factor from resistant cells underlies the effect. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) assays were used to identify factors secreted by cell lineages. While the less active estrone metabolite was detected in all lineages, the highly active estradiol was only detectable in mono- or coculture with resistant cells. As sensitive cells are more dependent on estrogen signaling than resistant cells, they benefit more from the increase in local estradiol, leading to facilitative growth when cocultured. Cooperative signaling between isogenic cancer cells is enhanced through addition of estradiol and blocked by small molecule inhibitors targeting estrogen signaling pathways. We have developed mathematical models that quantify the strength of competition and facilitation between cell lines and evaluated the effects of treatments that modify these interactions. These analyses support the conclusion that these heterogeneous cell lineages cooperate to survive during therapy through the increased production and sharing of local estradiol. This multidisciplinary approach reveals interactions between ER+ cancer lineages during treatment and provides insight into cell cooperation and competition during treatment, and how these interactions promote cancer cell growth and survival during treatment. Citation Format: Rena Emond, Vince K. Grolmusz, Jason Griffiths, Jinfeng Chen, Frederick R. Adler, Andrea Bild. Clonal facilitation drives estrogen receptor positive (ER+) breast cancer growth and survival [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 3133.

Optimized Polyethylene Glycolylated Polymer-Lipid Hybrid Nanoparticles as a Potential Breast Cancer Treatment.

Purpose: The aim of this work is to optimize a polyethylene glycolated (PEGylated) polymer–lipid hybrid nanoparticulate system for the delivery of anastrozole (ANS) to enhance its biopharmaceutical attributes and overall efficacy. Methods: ANS loaded PEGylated polymer–lipid hybrid nanoparticles (PLNPs) were prepared by a direct emulsification solvent evaporation method. The physical incorporation of PEG was optimized using variable ratios. The produced particles were evaluated to discern their particle size and shape, zeta-potential, entrapment efficiency, and physical stability. The drug-release profiles were studied, and the kinetic model was analyzed. The anticancer activity of the ANS PLNPs on estrogen-positive breast cancer cell lines was determined using flow cytometry. Results: The prepared ANS-PLNPs showed particle sizes in the range of 193.6 ± 2.9 to 218.2 ± 1.9 nm, with good particle size uniformity (i.e., poly-dispersity index of around 0.1). Furthermore, they exhibited relatively low zeta-potential values ranging from −0.50 ± 0.52 to 6.01 ± 4.74. The transmission electron microscopy images showed spherical shape of ANS-PLNPs and the compliance with the sizes were revealed by light scattering. The differential scanning calorimetry DSC patterns of the ANS PLNPs revealed a disappearance of the characteristic sharp melting peak of pure ANS, supporting the incorporation of the drug into the polymeric matrices of the nanoparticles. Flow cytometry showed the apoptosis of MCF-7 cell lines in the presence of ANS-PLNPs. Conclusion: PEGylated polymeric nanoparticles presented a stable encapsulated system with which to incorporate an anticancer drug (ANS) with a high percentage of entrapment efficiency (around 80%), good size uniformity, and induction of apoptosis in MCF-7 cells.

Bisphenol A-Induced Cell Proliferation and Mitochondrial Oxidative Stress Are Diminished via Modulation of TRPV1 Channel in Estrogen Positive Breast Cancer Cell by Selenium Treatment.

Cancer cell proliferation and apoptosis are induced by overload Ca2+ entry. Transient receptor potential vanilloid 1 (TRPV1) as a Ca2+ permeable cation channel is activated by capsaicin and reactive oxygen species (ROS), although it is blocked by capsazepine and sodium selenite (Na-Se). Bisphenol A (BPA) induces estrogenic action and further stimulates the proliferation of estrogen receptor positive MCF-7 cell through excessive production ROS and Ca2+ influx. However, whether or not Na-Se can influence BPA-induced oxidative stress and apoptosis through modulation of TRPV1 in breast cancer cells has not drawn much attention. The MCF-7 and MDA-MB-231 breast cancer cells were divided into four treatment groups as control, Na-Se (1μM for 2h), and BPA (0.1mM for 24h) and BPA + Na-Se. The Na-Se reduced BPA-induced increase of cell number, mitochondria oxidative stress, and TRPV1 channel activity modulation of MCF-7 cells, which was proved by the suppression of cell viability, excessive ROS production, mitochondrial membrane depolarization, lipid peroxidation, early apoptosis (Annexin-V), late apoptosis (propidium iodide) and upregulation of reduced glutathione, glutathione peroxidase, and cell death (propidium iodide/Hoechst rate). The similar effects of Na-Se were observed in the MCF-7 cells by capsazepine treatment. However, the effects of BPA were not observed in the MDA-MB-231 breast cancer cells. In conclusion, cell proliferative and oxidant effects of BPA were increased by activation of TRPV1, but its action on the values was decreased by the Na-Se treatment. The results may be a good set of preliminary data for designing animal studies on estrogenic effect of bisphenol A and antiestrogenic of selenium.

The novel cardio‐oncology drug, NP‐6A4, regulates the growth of multiple breast cancer cell lines through distinct cell‐specific mechanisms

While chemotherapeutic agents (anthracyclins, kinase‐inhibitors) have improved 5‐year breast cancer survival, their cardiovascular toxicity cause alarming increase in life‐threatening heart disease for millions of cancer survivors. Therefore, developing new cardio‐oncology drugs to protect heart during and after chemotherapy is an immediate critical need. Although literature indicate that Angiotensin II type 2 receptor AT2R attenuates cardiac damage, to date there are no AT2R agonists that are used in clinic to treat heart disease. NP‐6A4 is an AT2R peptide agonist that has recently received orphan drug designation for pediatric cardiomyopathy from the FDA. Our previous studies indicated that NP‐6A4 treatment (1.8mg/kg/day) could improve cardiac function and attenuate cardiomyopathy in diabetic rats and protect human cardiovascular cells from acute nutrient stress. We hypothesized that since AT2R is a regulator of cell growth, NP‐ 6A4‐AT2R signaling will attenuate breast cancer cell growth. Here we report NP‐6A4 treatment of triple negative breast cancer cells (MDA‐MB‐231) and estrogen positive breast cancer cells (MCF‐7) resulted in significant (p&lt;0.05) suppression of cell index (as determined by real time cell analyzer), and survival (as determined by MTS assay), albeit the underlying mechanisms were different. NP‐6A4 treatment of MCF‐7 cells augmented Tamoxifen‐induced inhibition of cell growth (p&lt;0.05), and suppressed proliferation marker Ki67 (20%) and phosphokinases CREB (32%), Jun N‐terminal kinase (JNK) (51%) and Erk1/2 (41%). In MDA‐MB‐231 cells, NP‐6A4 treatment caused increase in apoptotic marker Caspase 3 (2.3‐fold increase), but suppressed its inhibitor phosphokinase p38 (37%) (p&lt;0.05), and also suppressed phosphokinases CREB (30%), JNK (51%) and Erk1/2 (33%). However, doxorubicin (anthracycline)‐induced cell death was not reversed by NP‐6A4. NP‐6A4 treatment increased different tumor suppressors: ATIP 1 mRNA in MCF‐7 and ATIP‐3 mRNA in MDA‐MB‐231 (p&lt;0.05). These data suggest that NP‐6A4 differentially regulates human breast cancer cell growth and has high potential as a synergistic cardio‐oncology drug for breast cancer treatment.Support or Funding InformationThis work was supported by NIH grants: 1R01HL118376‐01 and 1R01HL138988‐01A1This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Effects of α-zearalenol on the metabolome of two breast cancer cell lines by 1H-NMR approach.

Zearalenone (ZEN) is one of the most widely distributed toxins that contaminates many crops and foods. Its major metabolites are α-Zearalenol (α-zol) and β-Zearalenol. Previous studies showed that ZEN and α-zol have estrogenic properties and are able to induce growth promoting effect in breast tissues. Considering that tumorigenesis is dependent on the reprogramming of cellular metabolism and that the evaluation of the cellular metabolome is useful to understand the metabolic changes that can occur during the cancer development and progression or after treatments, aim of our work is to study, for the first time, the effects of α-zol on the metabolomic profile of an estrogen positive breast cancer cell line, MCF-7, and of an estrogen negative breast cancer cell lines MDA-MB231. Firstly, we tested the effects of α-zol on the cell viability after 24, 48 and 72h of treatments with 10-10, 10-8 and 10-6M concentrations on breast cancer MCF-7 and MDA-MB231 cell lines in comparison to human non-cancerous breast MCF10A cell line. Then, we evaluated cell cycle progression, levels of reactive oxygen species (ROS) and the metabolomic profiling by 1H-NMR approach on MCF-7 and MDA-MB231 before and after 72h treatments. Principal component analysis was used to compare the obtained spectra. α-zol is resulted able to induce: (i) an increase of the cell viability on MCF-7 cells mainly after 72h treatment, (ii) a slight decrease of the cell viability on MDA-MB231 cells, and (iii) an increase of cells in S phase of the cell cycle and of ROS only in MCF-7 cells. Moreover, the evaluation of metabolomics profile evidenced that after treatment with α-zol the levels of some metabolites increased in MCF-7 cells whereas decreased slightly in MDA-MB231 cells. Our results showed that α-zol was able to increase the protein biosynthesis as well as the lipid metabolism in MCF-7 cells, and, hence, to induce an estrogen positive breast cancer progression.

Breast cancer amelioration by Butea monosperma in-vitro and in-vivo

Ethnopharmacological relevanceButea monosperma belonging to family Fabaceae is used in the Indian traditional medicine (Ayurveda) for various ailments including abdominal tumors and possess anti-estrogenic activity. Aim of the studyThe present study is aimed at investigating the chemo-preventive potential of Butea monosperma in breast cancer and elucidating it's mechanism of action by assessing its effect on key processes like apoptosis, angiogenesis and metastasis. MethodsCytotoxic potential of methanol extract of Butea monosperma flower (MEBM) was tested in MCF-7 (estrogen receptor positive), MDA-MB-231 (triple negative) and MDA-MB-453 (HER2 positive) human breast cancer cells by MTT assay. Chemo-preventive potential was evaluated in-vivo in Methylnitrosourea (MNU) induced mammary cancer in nulliparous Sprague-Dawley rats. The mechanism for anticancer potential was screened by in-vitro studies involving Annexin V- FITC assay (apoptosis), Chick Chorioallantoic Membrane assay (angiogenesis) and Migration assay (metastasis). Statistical analysis was done by one way and two way ANOVA (for Growth Rate and feed consumption efficiency) followed by post hoc Bonferroni's test with P value < 0.05. ResultsIt is observed that the exposure of MEBM, at various concentrations and time intervals to different cell lines, resulted in decreased cell proliferation. The IC50 value of MCF-7 cells was found significantly less than that of MDA-MB-231 and MDA-MB-453 cells, which indicated that the extract of said medicinal plant were more potent inhibitors of estrogen positive breast cancer cells than other types of breast cancer cells in vitro. Corroborative evidences were acquired in MNU actuated mammary carcinogenesis where MEBM constricted tumor parameters, decreased expression of estrogen and progesterone, nucleic acid content and increased latency period. MEBM also induced apoptosis, inhibited angiogenesis and metastasis in-vitro. ConclusionSelective cytotoxic activity in MCF-7 estrogen positive breast cancer cells and inhibition of growth of mammary carcinoma in-vivo by methanol extract of Butea monosperma flowers (MEBM) suggests chemo-prevention through modulation of estrogen and progesterone receptor, apoptotic, anti-angiogenesis and anti-metastatic activity.

Knockdown of PINCH-1 protein sensitizes the estrogen positive breast cancer cells to chemotherapy induced apoptosis

IntroductionPINCH-1 is a ubiquitously expressed protein belonging to the focal adhesion protein group which has a role in cell survival, spreading, adhesion and migration. It has been implicated in pathogenesis of several cancers. In the present study we aimed to investigate the role of this protein in estrogen positive and negative breast cancer subtypes. Materials and methodsPINCH-1 expression was studied in two estrogen positive(T47D and MCF-7) and one estrogen negative cell lines before and after treatment with six drugs (Cyclophosphamide, Celecoxib, Doxorubicin, Paclitaxel, Etoposide and Tamoxifen). Then the protein was knocked down using siRNA against PINCH-1 and change in percentage of apoptotic cells was analysed by flow cytometry. ResultsWe observed increased but differential expression of PINCH-1 in the three breast cancer cell lines with a higher expression in estrogen positive cell lines. Knocking down of PINCH-1 led to a significant (p-value < 0.05) enhancement in apoptosis in T47D cells in response to 4/6 (cyclophosphamide, celecoxib, paclitaxel, doxorubicin) drugs. Though an increase in apoptosis was observed in MCF-7 cells also, it was not found to be significant.The MDA-MB-231 cells however, did not show significant apoptosis upon PINCH-1 knockdown. ConclusionThe results suggest that PINCH-1 may be playing an important role in etiopathogenesis of both subtypes breast cancer. However, enhanced apoptosis observed only in estrogen positive and not in estrogen negative cells upon PINCH-1 knockdown point towards participation of some other protein with redundant functions in the later subtype which needs to be investigated.

Plumbagin sensitizes breast cancer cells to tamoxifen-induced cell death through GRP78 inhibition and Bik upregulation

The glucose regulated protein 78 (GRP78) is a major chaperone of the endoplasmic reticulum, and a prosurvival component of the unfolded protein response. GRP78 is upregulated in many types of cancers, including breast cancer. Research has suggested that GRP78 overexpression confers chemoresistance to anti-estrogen agents through a mechanism involving the inhibition of a pro-apoptotic BH3-only protein, Bik. In the present research the role of plumbagin, a naturally occurring naphthoquinone, in GRP78-associated cell death inhibition was examined. The results demonstrated that plumbagin inhibits GRP78 activity and GRP78 inhibition contributes to plumbagin-mediated cell death induction. Furthermore, Bik upregulation was associated with plumbagin-induced cell death and an increase in plumbagin-mediated Bik induction was observed upon GRP78 downregulation. Plumbagin sensitized estrogen-positive breast cancer cells to tamoxifen and the association of GRP78 inhibition and Bik upregulation in plumbagin-mediated cell sensitization was shown. Collectively, the results of this research suggest that plumbagin inhibits the antiapoptotic activity of GRP78 leading to Bik upregulation and apoptosis induction, which contributes to the sensitization of breast cancer cells to tamoxifen.

NDF induces expression of a novel 46 kD protein in estrogen receptor positive breast cancer cells.

Most human breast tumors start as estrogen-dependent, but during the course of the disease become refractory to hormone therapy. The transition of breast tumors from estrogen dependent to independent behavior may be regulated by autocrine and/or paracrine growth factor(s) that are independent of the estrogen receptor (ER). We have investigated the role(s) of NDF (neu-differentiation factor) in the biology of estrogen positive breast cancer cells by using MCF-7 cells as a model system. Treatment of MCF-7 cells with human recombinant NDF-beta 2 (NDF) inhibited the ER expression by 70% and this was associated with growth stimulation in an estrogen-independent manner. To explore the mechanism(s) of action of NDF in MCF-7 cells, we examined the expression of NDF-inducible gene products. We report here that NDF stimulated the levels of expression of a 46 kD protein (p46) (in addition to few minor proteins) in ER positive breast cancer cells including MCF-7, T-47-D, and ZR-75-R cells but not in ER negative breast cancer cells including MDA-231, SK-BR-3, and MDA-468 cells. This effect of NDF was due to induction in the rate of synthesis of new p46. The observed NDF-mediated induction of p46 expression was specific as there was no such effect by epidermal growth factor or 17-beta-estradiol, and inclusion of actinomycin D partially inhibited the p46 induction elicited by NDF. NDF-inducible stimulation of p46 expression was an early event (2-6 h) which preceded the period of down-regulation of ER expression by NDF. These results support the existence of NDF-responsive specific cellular pathway(s) that may regulate ER, and these interactions could play a role(s) in hormone-independence of ER positive breast cancer cells.

Identification of CETP as a molecular target for estrogen positive breast cancer cell death by cholesterol depleting agents

Cholesterol and its metabolites act as steroid hormone precursors, which promote estrogen receptor positive (ER+) breast cancer (BC) progression. Development of cholesterol targeting anticancer drugs has been hindered due to the lack of knowledge of viable molecular targets. Till now, Cholesteryl ester transfer protein (CETP) has been envisaged as a feasible molecular target in atherosclerosis, but for the first time, we show that CETP contributes to BC cell survival when challenged with cholesterol depleting agents. We show that MCF-7 CETP knockout BC cells pose less resistance towards cytotoxic compounds (Tamoxifen and Acetyl Plumbagin (AP)), and were more susceptible to intrinsic apoptosis. Analysis of differentially expressed genes using Ingenuity Pathway Analysis (IPA), in vivo tumor inhibition, and in vitro phenotypic responses to AP revealed a unique CETP-centric cholesterol pathway involved in sensitizing ER+ BC cells to intrinsic mitochondrial apoptosis. Furthermore, analysis of cell line, tissue and patient data available in publicly available databases linked elevated CETP expression to cancer, cancer relapse and overall poor survival. Overall, our findings highlight CETP as a pharmacologically relevant and unexploited cellular target in BC. The work also highlights AP as a promising chemical entity for preclinical investigations as a cholesterol depleting anticancer therapeutic agent.

Synthesis and mechanistic aspects of 2-anilinonicotinyl-pyrazolo[1,5-a]pyrimidine conjugates that regulate cell proliferation in MCF-7 cells via estrogen signaling

A series of anilinonicotinyl linked pyrazolo[1,5-a]pyrimidine conjugates (6a–x) were synthesized and evaluated for their antiproliferative activity. Some of these conjugates exhibited promising cytotoxic effects in the MCF-7 cell line and among these 6a and 6c exhibited significant effects, apart from G2/M cell cycle arrest. Interestingly they showed profound effects on cyclin D1, Bcl-2 and survivin proteins that regulate breast cancer cell proliferation. Moreover, ER alpha protein expression was studied to understand regulatory role of these conjugates on estrogen activity in estrogen positive breast cancer cells like MCF-7 and compounds 6a and 6c reduced their activity.

Hispolon inhibits the growth of estrogen receptor positive human breast cancer cells through modulation of estrogen receptor alpha

Human estrogen receptor α (ERα) is a nuclear transcription factor that is a major therapeutic target in breast cancer. The transcriptional activity of ERα is regulated by certain estrogen-receptor modulators. Hispolon, isolated from Phellinus linteus, a traditional medicinal mushroom called Sanghwang in Korea, has been used to treat various pathologies, such as inflammation, gastroenteric disorders, lymphatic diseases, and cancers. In this latter context, Hispolon has been reported to exhibit therapeutic efficacy against various cancer cells, including melanoma, leukemia, hepatocarcinoma, bladder cancer, and gastric cancer cells. However, ERα regulation by Hispolon has not been reported. In this study, we investigated the effects of Hispolon on the growth of breast cancer cells. We found that Hispolon decreased expression of ERα at both mRNA and the protein levels in MCF7 and T47D human breast cancer cells. Luciferase reporter assays showed that Hispolon decreased the transcriptional activity of ERα. Hispolon treatment also inhibited expression of the ERα target gene pS2. We propose that Hispolon, an anticancer drug extracted from natural sources, inhibits cell growth through modulation of ERα in estrogen-positive breast cancer cells and is a candidate for use in human breast cancer chemotherapy.

An Activin A/BMP2 chimera, AB215, blocks estrogen signaling via induction of ID proteins in breast cancer cells.

BackgroundOne in eight women will be affected by breast cancer in her lifetime. Approximately 75% of breast cancers express estrogen receptor alpha (ERα) and/or progesterone receptor and these receptors are markers for tumor dependence on estrogen. Anti-estrogenic drugs such as tamoxifen are commonly used to block estrogen-mediated signaling in breast cancer. However, many patients either do not respond to these therapies (de novo resistance) or develop resistance to them following prolonged treatment (acquired resistance). Therefore, it is imperative to continue efforts aimed at developing new efficient and safe methods of targeting ER activity in breast cancer.MethodsAB215 is a chimeric ligand assembled from sections of Activin A and BMP2. BMP2’s and AB215’s inhibition of breast cancer cells growth was investigated. In vitro luciferase and MTT proliferation assays together with western blot, RT_PCR, and mRNA knockdown methods were used to determine the mechanism of inhibition of estrogen positive breast cancer cells growth by BMP2 and AB215. Additionally in vivo xenograft tumor model was used to investigate anticancer properties of AB215.ResultsHere we report that AB215, a chimeric ligand assembled from sections of Activin A and BMP2 with BMP2-like signaling, possesses stronger anti-proliferative effects on ERα positive breast cancer cells than BMP2. We further show that AB215 inhibits estrogen signaling by inducing expression of inhibitor of DNA binding proteins (IDs). Specifically, we demonstrate that knockdown of ID proteins attenuates the anti-estrogen effects of AB215. Remarkably, we find that AB215 is more effective than tamoxifen in suppressing tumor growth in a xenograft model.ConclusionThis study shows that IDs have profound role to inhibit estrogen signaling in ERα positive breast cancer cells, and that engineered TGF-beta ligands may have high therapeutic value.Electronic supplementary materialThe online version of this article (doi:10.1186/1471-2407-14-549) contains supplementary material, which is available to authorized users.

Dinuclear berenil-platinum (II) complexes as modulators of apoptosis in human MCF-7 and MDA-MB231 breast cancer cells.

The metabolism of alkylating agents is accompanied by the generation of reactive oxygen species. The aim of this study was to treat estrogen receptor-positive and estrogen receptor-negative human breast cancer cells, MCF-7 and MDA-MB-231, respectively, with cisplatin and five different berenil-platinum (II) complexes, and then to investigate the oxidative modifications of DNA, lipid and protein, and to compare them with the profile of various pro- and antiapoptotic proteins. Changes in the levels of 8-hydroxy-2'-deoxyguanosine, 4-hydroxynonenal, carbonyl groups, dityrosine, active caspases 3, 8 and 9, as well as the expression of Bcl-2, Bax, cytochrome c, and p53 were subsequently examined. Activities of superoxide dismutase, catalase and glutathione, vitamin C levels were also investigated. Cellular reactions to cisplatin and the berenil-platinum (II) derivatives were more pronounced in MCF-7 cells as compared with the MDA-MB231 cells. Furthermore, the berenil-platinum (II) derivatives were found to be more effective than cisplatin. All of the complexes reduced the activity of superoxide dismutase and catalase, and also lowered the levels of non-enzymatic antioxidants. Increased level of lipid, protein as well as DNA damage markers was also observed after berenil-platinum (II) derivatives treatment. Similarly, the increase in the levels of the proapoptotic factors, were detected in MCF-7 and MDA-MB231 cells. Incubation of examined cells with the berenil-platinum (II) complexes also led to the increase in the levels of active caspases 3, 8 and 9. In conclusion, the results of the present study demonstrated that berenil-platinum (II) complexes more efficiently mediate cellular oxidative modifications and proapoptotic metabolism, particularly in MCF-7 cells, compared to cisplatin. Pt2(isopropylamine)4berenil2 and Pt2(piperidine)4(berenil)2 notably affected the cellular metabolism of estrogen-positive breast cancer cells. Thus, these complexes may be valuable for the design of additional anticancer drugs.

Dillenia Suffruticosa Extract Inhibits Proliferation of Human Breast Cancer Cell Lines (MCF-7 and MDA-MB-231) via Induction of G2/M Arrest and Apoptosis

The present research was designed to evaluate the anticancer properties of Dillenia suffruticosa extract. Our focus was on the mode of cell death and cell cycle arrest induced in breast cancer cells by the active fractions (designated as D/F4, D/F5 and EA/P2) derived from chromatographic fractionation of D. suffruticosa extracts. The results showed that the active fractions are more cytotoxic towards MCF-7 (estrogen positive breast cancer cells) and MDA-MB-231 (estrogen negative breast cancer cells) as compared to other selected cancer cell lines that included HeLa, A459 and CaOV3. The induction of cell death through apoptosis by the active fractions on the breast cancer cells was confirmed by Annexin V-FITC and PI staining. Cell cycle analysis revealed that D/F4 and EA/P2 induced G2/M phase cell cycle arrest in MCF-7 cells. On the other hand, MDA-MB-231 cells treated with D/F4 and D/F5 accumulated in the sub-G1 phase without cell cycle arrest, suggesting the induction of cell death through apoptosis. The data suggest that the active fractions of D. suffruticosa extract eliminated breast cancer cells through induction of apoptosis and cell cycle arrest. The reason why MCF-7 was more sensitive towards the treatment than MDA-MB-231 remains unclear. This warrants further work, especially on the role of hormones in response towards cytotoxic agents. In addition, more studies on the mechanisms underlying the induction of apoptosis and cell cycle arrest by the plant extract also need to be carried out.

Abstract 4415: Differential effects of biochanin A on cell proliferation and ROS-dependent pathways in estrogen receptor positive and HER-2 positive breast cancer cells.

Abstract The naturally occurring isoflavone biochanin A has been reported to have chemo-preventative properties towards cancer. Biochanin A exhibits antioxidant properties. Because of its antioxidant properties, biochanin A may be used to target breast cancer cells with high intracellular levels of reactive oxygen species (ROS). In this study, we investigated the effects of biochanin A on two cell lines — an estrogen receptor (ER) positive and a HER-2 positive breast cancer cell line. Biochanin A is implicated to affect both hormonal receptors and receptor tyrosine kinases. Overstimulation of ER is a basis for tumor progression due to the disruption of the cell cycle and apoptosis in estrogen positive breast cancer cells. Activation of HER-2 initiates cell growth, survival and invasion promoting cell signaling events in HER-2 positive breast cancer cells. MCF-7 (estrogen positive) and SK-BR-3 (HER-2 positive) cells were treated with biochanin A (2-100 μM) for 72 hours. Then MTT (cell survival) assay was carried out to determine the effects of biochanin A on cell survival. Our results suggest that biochanin A induces a dose-related inhibition of MCF-7 and SK-BR-3 cell viability at 50 μM. MCF-7 and SK-BR-3 cells were also treated with biochanin A (50 μM) for 12 hours and subsequently treated with hydrogen peroxide (H2O2)(2 μM) for 30 minutes: then western blotting was carried out to determine their expression of ERK and transcription factor NFκB. We found that biochanin A inhibits phospho-ERK pathway in SK-BR-3 but not in MCF-7 cells. However, expression of the transcription factor NFκB was decreases in both SK-BR-3 and MCF-7 cells. Thus, biochanin A may be an effective chemotherapeutic agent for breast cancer because of its ability to affect both hormonal receptors and receptor tyrosine kinases and to decrease intracellular ROS levels. (Supported by NIH INBRE P20RR016454, URC and MSTMRI) Citation Format: Lindsy Dickerson, Vikas Sehdev, Pamela L. Crowell, James C.K. Lai, Alok Bhushan. Differential effects of biochanin A on cell proliferation and ROS-dependent pathways in estrogen receptor positive and HER-2 positive breast cancer cells. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4415. doi:10.1158/1538-7445.AM2013-4415