Functionalized ferrocenes: The role of the para substituent on the phenoxy pendant group

Six ferrocenecarboxylates with phenyl, 4-(1H-pyrrol-1-yl)phenyl, 4-fluorophenyl, 4-chlorophenyl, 4-bromophenyl, 4-iodophenyl as pendant groups were synthesized and fully characterized by spectroscopic, electrochemical and X-ray diffraction methods. The anti-proliferative activity of these complexes were investigated in hormone dependent MCF-7 breast cancer and MCF-10A normal breast cell lines, to determine the role of the para substituent on the phenoxy pendant group. The 4-fluorophenyl ferrocenecarboxylate is inactive in both cell lines while 4-(1H-pyrrol-1-yl)phenyl ferrocenecarboxylate is highly cytotoxic in both cell lines. 4-chlorophenyl and 4-bromophenyl ferrocenecarboxylates have moderate to good anti-proliferative activity in MCF-7 and low anti-proliferative activity on normal breast cell line, MCF-10A whereas the 4-iodophenyl analog is highly toxic on normal breast cell line. The phenyl ferrocenecarboxylate has proliferative effects on MCF-7 and is inactive in MCF-10A. Docking studies between the complexes and the alpha-estrogen receptor (ER_α) were performed to search for key interactions which may explain the anti-proliferative activity of 4-bromophenyl ferrocenecarboxylate. Docking studies suggest the anti-proliferative activity of these ferrocenecarboxylates is attributed to the cytotoxic effects of the ferrocene group and not to anti-estrogenic effects.

Chemical composition and antiprolifrative activity of Artemisia persica Boiss. and Artemisia turcomanica Gand. essential oils

Essential oils obtained from aerial parts of Artemisia persica and Artemisia turcomanica were analyzed by GC/MS. While 28 components representing 91.01 % of A. persica were identified, the identity of 50 components, constituting 81.93 % of the total oil, was confirmed in A. turcomanica. β-thujone was the main compound (75.23%) in A. persica while the major identified phytochemicals in A. turcomanica were 1,8-cineol (19.23%), camphor (15.55%) and filifolone (15.53%). Both of the essential oils were predominantly made up of monoterpenes. Time- and dose-dependent cytotoxic effects of A. persica and A. turcomanica on MCF-7 cell line evaluated by MTT assay at 24, 48 and 72 h, showed that the highest cytotoxic effect of A. persica and A. turcomanica were appeared at 72 h incubation. At that incubation period, CI50 of A. persica was found to be 0.15 μg/ml, while that of A. turcomanica was 0.1 μg/ml. Thus, cytotoxicity of A. turcomanica was slightly higher than A. persica which could be attributed to the higher content of sesquiterpene present in A. turcomanica. As a conclusion, these volatile oils could have chemotherapeutic potentials.

Celecoxib Up Regulates the Expression of Drug Efflux Transporter ABCG2 in Breast Cancer Cell Lines

Elevated expression of the drug efflux transporter ABCG2 seems to correlate with multidrug resistance of cancer cells. Specific COX-2 inhibitor celecoxib has been shown to enhance the sensitivity of cancer cells to anticancer drugs. To clarify whether ABCG2 inhibition is involved in the sensitizing effect of celecoxib, we investigated whether the expression of ABCG2 in breast cancer cell lines, could be modulated by celecoxib. The expression of the multidrug resistant gene (ABCG2) at mRNA and protein level was detected by real-time quantitative reverse transcription-polymerase chain reaction and flow cytometry analysis, respectively. Among three human breast cancer cell lines ABCG2 and COX-2 were highly expressed in MCF7-MX and MDA-MB-231 cells, respectively. The COX-2 inhibitor celecoxib up-regulated the expression of ABCG2 mRNA in MCF-7 and MCF7-MX cells, which was accompanied by increased ABCG2 protein expression. While celecoxib was able to block the 12-O-tetradecanoylphorbol-13-acetate (TPA)-mediated increase in COX-2 expression in MDA-MB-231 cells, it increased the expression of ABCG2 up to 4.27 times to the control level at mRNA level and with less intensity at protein level. Our findings provide evidence that celecoxib up-regulates ABCG2 expression in human breast cancer cells and proposed that ABCG2 is not involved in chemosensitizing effects of celecoxib.

Modified arabinoxylan from rice bran, MGN-3/biobran, sensitizes metastatic breast cancer cells to paclitaxel in vitro

BACKGROUND

There is an increased interest in alternative treatments that reduce the toxicity of chemotherapy by lowering the drug concentration, whilst maintaining potency against cancer cells. Previous studies have demonstrated that arabinoxylan from rice bran, MGN-3/Biobran, sensitizes human breast cancer cells (BCC) to daunorubicin (DNR). In the present study, we further evaluated the ability of MGN-3 to sensitize cells to another chemotherapy agent, paclitaxel.

MATERIALS AND METHODS

Non-metastatic MCF-7 (human BCC) and metastatic 4T1 (murine BCC) cells were cultured with different concentrations of paclitaxel in the presence or absence of MGN-3. Cell survival, DNA damage, and cell proliferation were examined.

RESULTS

MGN-3 increased the susceptibility of both types of cancer cells to paclitaxel by over 100-fold. Mechanistically, MGN-3 works synergistically with paclitaxel by causing DNA damage, enhancing apoptosis, and inhibiting cell proliferation in 4T1 cells.

CONCLUSION

Our data demonstrate that MGN-3 is an effective chemosensitizer and may represent a novel adjuvant for the treatment of metastatic breast cancer.

MART-10, a less calcemic vitamin D analog, is more potent than 1α,25-dihydroxyvitamin D3 in inhibiting the metastatic potential of MCF-7 breast cancer cells in vitro

With the recent advance in breast cancer therapy, the survival rate of breast cancer patients has improved greatly. In spite of the progress, 25-50% of breast cancer patients eventually will develop metastasis. Due to limited early detection methods, metastasis is usually diagnosed at the late stages beyond recovery likely due to resistance to currently available breast cancer therapies. Thus, a new strategy to prevent cancer cell growth and repress tumor metastasis is desirable. The active form of vitamin D3, 1α,25-dihydroxyvitamin D3 [1α,25(OH)2D3], has anti-invasion and anti-migration properties in pre-clinical studies, yet its clinical application has been hampered by its hypercalcemic side effect. Previously, we have demonstrated that a new class of less-calcemic vitamin D analog, 19-nor-2α-(3-hydroxypropyl)-1α,25-dihydroxyvitamin D3 (MART-10), is 1000-fold more active than 1α,25(OH)2D3 in suppressing MCF-7 cells growth through cell cycle arrest and apoptosis induction. In the current study, we show for the first time that MART-10 is more active than 1α,25(OH)2D3 in preventing MCF-7 cell invasion and migration likely mediated through the upregulation of E-cadherin, and the downregulation of Snail, Slug, and Twist, the transcription factors implicated in epithelial-mesenchymal transition (EMT), as well as MMP-13. Based on the current in vitro and the highly anti-tumor characteristics of MART-10 in a pancreatic xenograft model, MART-10 is deemed as a promising candidate for breast cancer treatment. Further in vivo animal study comparing MART-10 with 1α,25(OH)2D3 and other potent and less calcemic analogs of vitamin D is warranted.

Cycloartane Triterpenoids from Euphorbia Macrostegia with their Cytotoxicity against MDA-MB48 and MCF-7 Cancer Cell Lines

The dried plant was extracted with dichloromethane and after defatting with hexane, transferred repeatedly on silica columns using dichloromethane-hexane and ethyl acetate-hexane as mobile phases. Finally the fractions were purified by high performance liquid chromatography using a Pack-Sil column and hexane: Ethyl acetate as mobile phase. The structures of the isolated compounds included: cycloart-25-ene-3β, 24-diol (1), cycloart-23(Z)-ene-3β, 25-diol (2), cycloart-23(E)-ene-3β, 25-diol (3), and 24-methylene-cycloart-3β-ol (4) were elucidated by (13)C- and (1)H-NMR as well as IR and by the aid of mass fragmentation pattern and comparing with the literature. The biological effects of the compounds were done by the MTT assay on two different cancer cell lines including MDA-MB48 and MCF-7. Among these compounds, cycloart-23(E)-ene-3β,25-diol (3) was the most active compound on MDA-MB468 cell line (LD50 = 2.05 μgmL(- 1) ) and cycloart-23(Z)-ene-3β, 25-diol (2) was the most active compound on MCF-7 cell line (LD50 = 5.4 μgmL(- 1)).

Characterizing the metabolic heterogeneity in human breast cancer xenografts by 3D high resolution fluorescence imaging

We previously reported that tumor mitochondrial redox state and its heterogeneity distinguished between the aggressive and the indolent breast cancer xenografts, suggesting novel metabolic indices as biomarkers for predicting tumor metastatic potential. Additionally, we reported that the identified redox biomarkers successfully differentiated between the normal breast tissue and the cancerous breast tissue from breast cancer patients. The aim of the present study was to further characterize intratumor heterogeneity by its distribution of mitochondrial redox state and glucose uptake pattern in tumor xenografts and to further investigate the metabolic heterogeneity of the clinical biopsy samples. We employed the Chance redox scanner, a multi-section cryogenic fluorescence imager to simultaneously image the intratumor heterogeneity in the mitochondrial redox state and glucose uptake at a high spatial resolution (down to 50 × 50 × 20 μm(3)). The mitochondrial redox state was determined by the ratio of the intrinsic fluorescence signals from reduced nicotinamide adenine dinucleotide (NADH) and oxidized flavoproteins (Fp including FAD, i.e., flavin adenine dinucleotide), and the glucose uptake was measured using a near-infrared fluorescent glucose-analogue, pyropheophorbide 2-deoxyglucosamide (Pyro-2DG). Significant inter- and intratumor metabolic heterogeneity were observed from our imaging data on various types of breast cancer xenografts. The patterns and degrees of heterogeneity of mitochondrial redox state appeared to relate to tumor size and metastatic potential. The glucose uptake was also heterogeneous and generally higher in tumor peripheries. The oxidized and reduced regions mostly corresponded with the lower and the higher pyro-2DG uptake, respectively. However, there were some regions where the glucose uptake did not correlate with the redox indices. Pronounced glucose uptake and high NADH were observed in certain localized areas within the tumor necrotic regions, indicative of the existence of viable cells which was also supported by the H&E staining. Significant heterogeneity of the redox state indices was also observed in clinical specimens of breast cancer patients. As abnormal metabolism including the Warburg effect (high glycolysis) plays important roles in cancer transformation and progression, our observations that reveal the 3D intratumor metabolic heterogeneity as a characteristic feature of breast tumors are of great importance for understanding cancer biology and developing diagnostic and therapeutic methods.

Exploring a natural MDR reversal agent: potential of medicinal food supplement Nerium oleander leaf distillate

OBJECTIVE

To investigate the molecular effects of Nerium oleander leaf distillate on paclitaxel and vincristine resistant (MCF-7/Pac and MCF-7/Vinc) cells and sensitive (MCF-7/S) cell lines.

METHODS

Nerium oleander (N. oleander) leaf extract was obtained by hydrodistillation method. The toxicological effects of N. oleander distillate, previously suggested as medicinal food supplement, on drug resistant cells were evaluated by XTT tests. MDR modulation potential of the plant material was evaluated by flow cytometry and fluorescent microscopy. Paclitaxel and vincristine were applied to the sublines in combination with N. oleander distillate.

RESULTS

Fractional inhibitory indices show that N. oleander distillate did not increase the antiproliferative effects of anticancer drugs. N. oleander treatment in to MCF-7/Pac and MCF-7/Vinc did not inhibit P-gp activity and MDR1 gene expression level.

CONCLUSIONS

As a result it may be suggested that although N. oleander distillate has some medicinal effects as food supplement it may not be suitable as an MDR modulator for drug resistant breast cancer cells.

Recycling antimalarial leads for cancer: Antiproliferative properties of N-cinnamoyl chloroquine analogues

Cinnamic acids and quinolines are known as useful scaffolds in the discovery of antitumor agents. Therefore, N-cinnamoylated analogues of chloroquine, recently reported as potent dual-action antimalarials, were evaluated against three different cancer cell lines: MKN-28, Caco-2, and MCF-7. All compounds display anti-proliferative activity in the micromolar range against the three cell lines tested, and most of them were more active than their parent drug, chloroquine, against all cell lines tested. Hence, N-cinnamoyl-chloroquine analogues are a good start towards development of affordable antitumor leads.

The β-carboline alkaloid harmine inhibits telomerase activity of MCF-7 cells by down-regulating hTERT mRNA expression accompanied by an accelerated senescent phenotype

The end replication problem, which occurs in normal somatic cells inducing replicative senescence, is solved in most cancer cells by activating telomerase. The activity of telomerase is highly associated with carcinogenesis which makes the enzyme an attractive biomarker in cancer diagnosis and treatment. The indole alkaloid harmine has multiple pharmacological properties including DNA intercalation which can lead to frame shift mutations. In this study, harmine was applied to human breast cancer MCF-7 cells. Its activity towards telomerase was analyzed by utilizing the telomeric repeat amplification protocol (TRAP). Our data indicate that harmine exhibits a pronounced cytotoxicity and induces an anti-proliferation state in MCF-7 cells which is accompanied by a significant inhibition of telomerase activity and an induction of an accelerated senescence phenotype by over-expressing elements of the p53/p21 pathway.

A study on the inhibitory effect of polysaccharides from Radix ranunculus ternati on human breast cancer MCF-7 cell lines

The objective of this paper was to study the in vitro anti-breast cancer activity of polysaccharides from Radix ranunculus ternati. Different concentrations of polysaccharide extracts were selected, and MTT assay and flow cytometry (FCM) were used to investigate their growth-inhibitory and apoptosis-inducing effects on human breast cancer MCF-7 cell lines. Radix ranunculus ternati polysaccharides had varying degrees of effects on the growth of human breast cancer MCF-7 cell lines, and the differences were significant compared with the blank control group. FCM showed that the polysaccharides can induce apoptosis. In addition, it can also enhance NK cell activity. Radix ranunculus ternati polysaccharides have a relatively good in-vitro anti-breast cancer activity.

ErbB2 upregulates the Na+,HCO3(-)-cotransporter NBCn1/SLC4A7 in human breast cancer cells via Akt, ERK, Src, and Kruppel-like factor 4

Misregulation of acid-base transport plays central roles in cancer development. We previously demonstrated the strong up-regulation of the Na(+),HCO3(-) cotransporter NBCn1 (SLC4A7) in MCF-7 breast cancer cells by a truncated, constitutively active ErbB2 (HER2) receptor, ΔNErbB2, and showed that NBCn1 expression and activity are increased in breast cancer tissue from patients. Here, we present the first in-depth characterization of an SLC4A7 promoter and identify its minimal ΔNErbB2-sensitive region. Inhibition or siRNA-mediated knockdown of PI3K, Akt1, ERK1/2, or Src decreased the NBCn1 protein level in ΔNErbB2-expressing MCF-7 cells by ~50, 60, 30 and 35%, respectively. Further, knockdown of the transcription factor Krüppel-like factor 4 (KLF4) reduced NBCn1 protein expression by ~40%, and KLF4 overexpression increased NBCn1 expression by 50-80%. In contrast, knockdown of the closely related transcription factor specificity protein 1 (Sp1) or transfection with dominant-negative Sp1 increased NBCn1 expression by ~35 and ~50%, respectively. NBCn1 expression was also increased by stimulation of full-length ErbB1, -2, and -3 receptors in SKBr3 cells (1.5- and 2-fold by NRG1 or EGF, respectively) or after their exogenous expression in MCF-7 cells. Finally, stimulation with NRG1 or EGF more than doubled acid extrusion capacity in SKBr3 cells. In conclusion, NBCn1 is strongly upregulated by ErbB receptor signaling in a manner involving opposite effects of KLF4 and Sp1, transcription factors with central roles in cancer development. ErbB-induced up-regulation of NBCn1-mediated acid extrusion may play important physiological and pathophysiological roles in the breast epithelium and other tissues with high ErbB receptor levels.

The β-carboline alkaloid harmine inhibits telomerase activity of MCF-7 cells by down-regulating hTERT mRNA expression accompanied by an accelerated senescent phenotype

The end replication problem, which occurs in normal somatic cells inducing replicative senescence, is solved in most cancer cells by activating telomerase. The activity of telomerase is highly associated with carcinogenesis which makes the enzyme an attractive biomarker in cancer diagnosis and treatment. The indole alkaloid harmine has multiple pharmacological properties including DNA intercalation which can lead to frame shift mutations. In this study, harmine was applied to human breast cancer MCF-7 cells. Its activity towards telomerase was analyzed by utilizing the telomeric repeat amplification protocol (TRAP). Our data indicate that harmine exhibits a pronounced cytotoxicity and induces an anti-proliferation state in MCF-7 cells which is accompanied by a significant inhibition of telomerase activity and an induction of an accelerated senescence phenotype by over-expressing elements of the p53/p21 pathway.

Anastrozole and RU486: Effects on estrogen receptor α and Mucin 1 expression and correlation in the MCF-7 breast cancer cell line

Anastrozole and RU486 are shown to reduce hormone-responsive breast cancer progression when used as adjuvant treatments to surgical intervention, however, a high incidence of cancer recurrence remains. Estrogen receptor alpha (ERα) and Mucin 1 (MUC1), a glycoprotein, are both implicated in breast cancer progression. We assessed whether Anastrozole and RU486 treatment affects the expression of, and relationship between, ERα and MUC1 in the ERα(+) MUC1(+) MCF-7 breast cancer cell line. MCF-7 cells, treated with physiological concentrations of either Anastrozole or RU486 for 18 h or 72 h, were subjected to immunolocalization of both markers. CellProfiler software was used to quantify intensity for statistical analyses. ERα expression increased at both time periods following treatment. MUC1 expression increased with RU486-treatment at both times, whereas Anastrozole induced increased MUC1 expression at 72 h only. The biomarkers demonstrated increased point association at 72 h within treatment groups despite MUC1 diverging from correlation with ERα. We propose that tumor progression is independent of MUC1 and ERα correlation. These preliminary results indicate that withdrawal of adjuvant treatment may result in residual cell populations expressing increased ERα and MUC1. This phenotype may allow enhanced estrogenic and metastatic capacity influencing cancer recurrence, a hypothesis we are investigating further.

Biological activity of 3-chloro-azetidin-2-one derivatives having interesting antiproliferative activity on human breast cancer cell lines

Resveratrol (3,4',5 tri-hydroxystilbene), a natural plant polyphenol, has gained interest as a non-toxic agent capable of inducing tumor cell death in a variety of cancer types. However, therapeutic application of these beneficial effects remains very limited due to its short biological half-life, labile properties, rapid metabolism and elimination. Different studies were undertaken to obtain synthetic analogs of resveratrol with major bioavailability and anticancer activity. We have synthesized a series 3-chloro-azetidin-2-one derivatives, in which an azetidinone nucleus connects two aromatic rings. Aim of the present study was to investigate the effects of these new 3-chloro-azetidin-2-one resveratrol derivatives on human breast cancer cell lines proliferation. Our results indicate that some azetidin-based resveratrol derivatives may become new potent alternative tools for the treatment of human breast cancer.

Zoledronic acid-induced cytotoxicity through endoplasmic reticulum stress triggered REDD1-mTOR pathway in breast cancer cells

BACKGROUND

Zoledronic acid (ZOL) used for the prevention/treatment of osteopathic complications has been reported to have antitumor effects in breast cancer treatment. However, little is known about the exact molecular mechanisms for antitumor actions of ZOL. In this study, two breast cancer cell lines were used to investigate the antitumor efficacy of ZOL and the underlying molecular mechanisms.

RESULTS

The growth of two breast cancer cell lines was markedly decreased following treatment with ZOL. Compared with MCF-7 cells, MDA-MB-231 cells were more sensitive to ZOL treatment. Western blot analysis showed that the inhibitory effect of zoledronic acid on growth was related to the extent of inhibition of phosphorylated-protein kinase B (p-AKT), and phosphorylated-mammalian target of rapamycin (p-mTOR). Moreover, the expression of the stress-responsive protein regulated in development and DNA damage response 1 (REDD1), an inhibitor of mTOR, was induced markedly to various degrees in different breast cancer cell lines after ZOL treatment. Interestingly, by examining the upstream signaling pathway of REDD1, we found that ZOL can induce endoplasmic reticulum stress responses through activating the protein kinase R (PKR)-related ER kinase-eukaryotic initiation factor 2 alpha-CCAAT/enhancer binding protein homologous protein (PERK-eIF2α-CHOP) pathway.

CONCLUSION

Taken together, these results indicated that ZOL-induced cell death was caused by endoplasmic reticulum stress activating PERK-eIF2α-CHOP pathway to induce REDD1 expression and inhibit the mTOR pathway.

Macrophage apolipoprotein E and proliferation of MCF-7 breast cancer cells: role of LXR

BACKGROUND

Apolipoprotein E (APOE), a lipid transport protein that has a key role in the lipoprotein metabolism, is expressed by macrophages under the control of the transcription factor Liver X Receptor (LXR), an oxysterol-activated transcriptional factor involved in cholesterol metabolism. Recent work has shown that LXR agonists may inhibit breast cancer cell proliferation in vitro. We hypothesized that LXR-activated macrophages, and in particular secreted macrophagic APOE, may potentiate the effect of LXR agonists. Our goal was to evaluate the effect of APOE, secreted by THP-1 macrophages under the control of LXR, on MCF-7 cell proliferation, a model of breast cancer.

MATERIALS AND METHODS

MCF-7 cells were incubated with supernatants from THP-1 cells previously treated with LXR agonists [T0901317 or 22(R)-hydroxycholestrol], or supernatants from THP-1 cells transfected with siRNA against APOE mRNA.

RESULTS

Viability assays and cell death quantification showed that media from LXR-activated macrophages reduced cell proliferation and increased apoptosis of MCF-7 cells. Interestingly, the opposite effects were observed when MCF-7 cells wre treated with media from the siRNA APOE-mediated knock-down model.

CONCLUSION

This study highlights the protective role of LXR-activated macrophages against breast cancer growth, and the implication of APOE protein in the anti-proliferative and pro-apoptotic effects observed.

An aptasensor for sensitive detection of human breast cancer cells by using porous GO/Au composites and porous PtFe alloy as effective sensing platform and signal amplification labels

A novel aptamer biosensor for cancer cell assay has been reported on the basis of ultrasensitive electrochemical detection. The assay uses the aptamer as a capture probe to recognize and bind the tumor marker on the surface of the cancer cells, forming an aptamer-based sandwich structure for MCF-7 cells detection. Functionalized nanoporous materials, porous graphene oxide/Au composites (GO/Au composites) and porous PtFe alloy have been introduced into the biosensor. Owing to the large surface area and versatile porous structure, the use of nanoporous materials can significantly improve the analysis performance of the biosensors by loading of large amounts of molecules and accelerating diffusion rate. Under the optimized experimental conditions, the proposed aptamer biosensor exhibited excellent analytical performance for MCF-7 cells determination, ranging from 100 to 5.0×10(7) cells mL(-1) with the detection limit of 38 cells mL(-1). The biosensor showed good selectivity, acceptable stability and reproducibility, and developed a highly sensitive and selective method for cancer cells detection.

Cell chip with a thiolated chitosan self-assembled monolayer to detect the effects of anticancer drugs on breast normal and cancer cells

Cell-based chips are an effective in vitro analysis tool; however, the sensitivity of the cell chip to biomaterials is high, which is crucial for immobilizing cells on the electrode surface without conductivity. In this study, we report on a cell chip with a thiolated chitosan monolayer that was easy to fabricate, highly adhesive to cells, and enhanced electrochemical signals. Thiolated chitosan containing thiol groups was synthesized and self-assembled on a gold electrode to immobilize cells, and showed superior electrochemical performance to that of poly-l-lysine and collagen. Cyclic voltammetry (CV) was performed to distinguish the redox characteristics of normal (HMEC) and breast cancer cells (MCF-7); then, two anticancer drugs (doxorubicin and cyclophosphamide) were added to the cell cultures to analyze their effects on the redox environment of normal and cancer cells derived from the same origin. As a result, the CV cathode peaks decreased differently with respect to the cell line (normal and cancer) and anticancer drug, which was validated by a conventional MTT viability assay. Hence, the proposed cell chip with a thiolated chitosan modified layer could be used in various fields, including discriminating normal from cancer cells, to evaluating the efficiency of newly developed drugs, and to assessing cytotoxicity of various chemicals.

Insights into significant pathways and gene interaction networks underlying breast cancer cell line MCF-7 treated with 17β-estradiol (E2)

OBJECTIVE

Estrogens are known to regulate the proliferation of breast cancer cells and to alter their cytoarchitectural and phenotypic properties, but the gene networks and pathways by which estrogenic hormones regulate these events are only partially understood.

METHODS

We used global gene expression profiling by Affymetrix GeneChip microarray analysis, with KEGG pathway enrichment, PPI network construction, module analysis and text mining methods to identify patterns and time courses of genes that are either stimulated or inhibited by estradiol (E2) in estrogen receptor (ER)-positive MCF-7 human breast cancer cells.

RESULTS

Of the genes queried on the Affymetrix Human Genome U133 plus 2.0 microarray, we identified 628 (12h), 852 (24h) and 880 (48 h) differentially expressed genes (DEGs) that showed a robust pattern of regulation by E2. From pathway enrichment analysis, we found out the changes of metabolic pathways of E2 treated samples at each time point. At 12h time point, the changes of metabolic pathways were mainly focused on pathways in cancer, focal adhesion, and chemokine signaling pathway. At 24h time point, the changes were mainly enriched in neuroactive ligand-receptor interaction, cytokine-cytokine receptor interaction and calcium signaling pathway. At 48 h time point, the significant pathways were pathways in cancer, regulation of actin cytoskeleton, cell adhesion molecules (CAMs), axon guidance and ErbB signaling pathway. Of interest, our PPI network analysis and module analysis found that E2 treatment induced enhancement of PRSS23 at the three time points and PRSS23 was in the central position of each module. Text mining results showed that the important genes of DEGs have relationship with signal pathways, such as ERbB pathway (AREG), Wnt pathway (NDP), MAPK pathway (NTRK3, TH), IP3 pathway (TRA@) and some transcript factors (TCF4, MAF).

CONCLUSIONS

Our studies highlight the diverse gene networks and metabolic and cell regulatory pathways through which E2 operates to achieve its widespread effects on breast cancer cells.

Identification and characterisation of ROS modulator 1 in Lampetra japonica

Reactive oxygen species (ROS) are a heterogeneous group of highly reactive molecules that oxidise targets in biological systems. ROS are also considered important immune regulators. In this study, we identified a homologue of reactive oxygen species modulator 1 (Romo1) in the Japanese lamprey (Lampetra japonica). The L japonica Romo1 (Lj-Romo1) gene shares high sequence homology with the Romo1 genes of jawed vertebrates. Real-time quantitative PCR demonstrated the wide distribution of Lj-Romo1 in lamprey tissues. Furthermore, after the lampreys were stimulated with lipopolysaccharide (LPS), the level of Lj-Romo1 mRNA was markedly up-regulated in the liver, gill, kidney, and intestine tissues. Lj-Romo1 was localised to the mitochondria and has the capacity to increase the ROS level in cells. The results obtained in the present study will help us to understand the roles of Romo1 in ROS production and innate immune responses in jawless vertebrates.

PPARβ mRNA expression, reduced by n-3 PUFA diet in mammary tumor, controls breast cancer cell growth

The effect of numerous anticancer drugs on breast cancer cell lines and rodent mammary tumors can be enhanced by a treatment with long-chain n-3 polyunsaturated fatty acids (n-3 PUFA) such as docosahexaenoic acid (DHA, 22:6n-3) which is a natural ligand of peroxisome proliferator-activated receptors (PPAR). In order to identify the PPAR regulating breast cancer cell growth, we tested the impact of siRNA, selected to suppress PPARα, PPARβ or PPARγ mRNA in MDA-MB-231 and MCF-7 breast cancer cell lines. The siPPARβ was the most effective to inhibit breast cancer cell growth in both cell lines. Using PPARα, PPARβ and PPARγ pharmacological antagonists, we showed that PPARβ regulated DHA-induced inhibition of growth in MDA-MB-231 and MCF-7 cells. In addition, the expressions of all 3 PPAR mRNA were co-regulated in both cell lines, upon treatments with siRNA or PPAR antagonists. PPAR mRNA expression was also examined in the NitrosoMethylUrea (NMU)-induced rat mammary tumor model. The expressions of PPARα and PPARβ mRNAs were correlated in the control group but not in the n-3 PUFA group in which the expression of PPARβ mRNA was reduced. Although PPARα expression was also increased in the n-3 PUFA-enriched diet group under docetaxel treatment, it is only the expression of PPARβ mRNA that correlated with the regression of mammary tumors: those that most regressed displayed the lowest PPARβ mRNA expression. Altogether, these data identify PPARβ as an important player capable of modulating other PPAR mRNA expressions, under DHA diet, for inhibiting breast cancer cell growth and mammary tumor growth.

Tissue-selective estrogen complexes for postmenopausal women

Although hormone therapy using estrogens plus progestogens (EPT) is effective for the management of menopausal symptoms (e.g., vasomotor symptoms and vulvar/vaginal atrophy) and prevention/treatment of postmenopausal osteoporosis, EPT is associated with safety and tolerability concerns. A new alternative to EPT is the tissue selective estrogen complex (TSEC), which partners a selective estrogen receptor modulator (SERM) with one or more estrogens and is designed to treat menopausal symptoms and prevent postmenopausal osteoporosis without the tolerability concerns associated with EPT. The first TSEC to reach advanced clinical development is a combination of the SERM bazedoxifene (BZA) with conjugated estrogens (CE). BZA has been shown to inhibit the stimulatory activity of CE on uterine tissue and breast in vitro and in vivo. In clinical studies, BZA/CE treatment has been associated with significant improvements in menopausal symptoms including hot flushes and vulvar/vaginal atrophy and significant increases in bone mineral density, coupled with reductions in bone turnover marker levels and improvements in sleep and health-related quality of life. Additionally, BZA/CE has been shown to have a neutral effect on endometrial and breast tissue because BZA inhibits the stimulatory effects of estrogens in tissue-selective fashion in these 2 organs. Taken together, results of these preclinical and clinical studies indicate that the benefits of estrogens for treating menopausal symptoms are maintained with BZA/CE without endometrial or breast stimulation, resulting in a safe and effective treatment for symptomatic postmenopausal women.

Genomic DNA of MCF-7 breast cancer cells not an ideal choice as positive control for PCR amplification based detection of Mouse Mammary Tumor Virus-Like Sequences

The identification of the etiology of breast cancer is a crucial research issue for the development of an effective preventive and treatment strategies. Researchers are exploring the possible involvement of Mouse Mammary Tumor Virus (MMTV) in causing human breast cancer. Hence, it becomes very important to use a consistent positive control agent in PCR amplification based detection of MMTV-Like Sequence (MMTV-LS) in human breast cancer for accurate and reproducible results. This study was done to investigate the feasibility of using genomic DNA of MCF-7 breast cancer cells to detect MMTV-LS using PCR amplification based detection. MMTV env and SAG gene located at the 3' long terminal repeat (LTR) sequences were targeted for the PCR based detection. No amplification was observed in case of the genomic DNA of MCF-7 breast cancer cells. However, the 2.7 kb DNA fragment comprising MMTV env and SAG LTR sequences yielded the products of desired size. From these results it can be concluded that Genomic DNA of MCF-7 cell is not a suitable choice as positive control for PCR or RT-PCR based detection of MMTV-LS. It is also suggested that plasmids containing the cloned genes or sequences of MMTV be used as positive control for detection of MMTV-LS.

Egg wash wastewater: estrogenic risk or environmental asset?

Commercial production of eggs and egg products requires the washing of eggs to remove urinary-fecal material and broken egg residue. In the case of one Ohio farming facility, 1.6 million birds produce 1.4 million eggs per day, using approximately 50 mL of wash water/egg or approximately 70,000 L per day. The aqueous waste stream was evaluated for estrogenicity to determine if potential for endocrine disruption would result from agricultural application of such wastewater. Samples collected the Fall (October) of 2010 included: water from 2 egg washers operating in series, inlet pipe to the treatment lagoon, a lagoon composite, and products used within the facility in the cleaning of equipment and treatment of the waste. In February 2011, the treatment lagoon was fitted with an extensive aeration system and subsequent sample sets were collected on 3 consecutive days in May and November. Samples were extracted by solid phase extraction and assayed for estrogenic activity using the in vitro E-Screen assay. Raw untreated wastewater from the egg washers contained 17β-estradiol equivalents (E2 Eqs) ranging from 9 to 18 ng/L, pipe grab samples entering into the treatment lagoon ranged from <0.14 to 4.4 ng/L (variability related to time of emptying of egg wash tanks), whereas treatment lagoon water contained 0.3 to 4.0 ng/L E2 Eq. Addition of an aeration system to the treatment lagoon eliminated surface "frothing," reduced noxious odor emission, and E2 Eqs were lower than the pre-aeration concentrations (4 ng/L [n = 1, no statistical comparison possible] vs 0.3 to 1.4 ng/L in 2011). Because of matrix effects, estrogens were not quantifiable by LC-MS2 in even egg washwater extracts, at concentrations in which internal deuterated estrogen standards were quantifiable. Estrone and E2 parent ions were detected in egg washwater samples only, and confirmatory ion fragments were detected in only one of these samples. Estrogenicity of the wastewater from the treatment lagoon was already at the proposed aquatic no effect concentration for 17β-E2 and would be expected to decrease further as wastewater passes through 2 consecutive storage ponds before application on field crops for irrigation. The original project plan was to follow the wastewater as it was applied by aerial irrigation and concomitant surface runoff, but based on the consistent and extremely low concentration of estrogenic activity of the wastewater from the treatment lagoon, it was concluded that activity would be below limits of quantitation by E-Screen in water used for irrigation from the storage ponds. Use of egg wash wastewater--or gray water--to irrigate crops removes the cost and burden of wastewater treatment by the local wastewater plant, poses little to no potential threat of estrogenic endocrine disruption, and supports the conservation of water resources through the use of wastewater irrigation.

Synthesis and cytotoxic activity evaluation of 2,3-thiazolidin-4-one derivatives on human breast cancer cell lines

It is well known that resveratrol (RSV) displayed cancer-preventing and anticancer properties but its clinical application is limited because of a low bioavailability and a rapid clearance from the circulation. Aim of this work was to synthesize pharmacologically active resveratrol analogs with an enhanced structural rigidity and bioavailability. In particular, we have synthesized a library of 2,3-thiazolidin-4-one derivatives in which a thiazolidinone nucleus connects two aromatic rings. Some of these compounds showed strong inhibitory effects on breast cancer cell growth. Our results indicate that some of thiazolidin-based resveratrol derivatives may become a new potent alternative tool for the treatment of human breast cancer.

A diverse induction of apoptosis by trabectedin in MCF-7 (HER2-/ER+) and MDA-MB-453 (HER2+/ER-) breast cancer cells

Trabectedin (Yondelis, ET-743), a semi synthetic tetrahydroisoquinoline alkaloid that was originally derived from the marine tunicate Ecteinascidia turbinata. The objective of this study was to investigate whether trabectedin mediated apoptosis shows any diversity in human breast cancer cell lines with different genotypes. Trabectedin induced cytotoxicity and apoptosis in both breast cancer cells in a time and concentration-dependent manner. The expression levels of the death receptor pathway molecules, TRAIL-R1/DR4, TRAIL-R2/DR5, FAS/TNFRSF6, TNF RI/TNFRSF1A, and FADD were significantly increased by 2.6-, 3.1-, 1.7-, 11.2- and 4.0-fold by trabectedin treatment in MCF-7 cells. However, in MDA-MB-453 cells, the mitochondrial pathway related pro-apoptotic proteins Bax, Bad, Cytochrome c, Smac/DIABLO, and Cleaved Caspase-3 expressions were induced by 4.2-, 3.6-, 4.8-, 4.5-, and 4.4-fold, and the expression levels of anti-apoptotic proteins Bcl-2 and Bcl-XL were reduced by 4.8- and 5.2-fold in MDA-MB-453 cells. Moreover, trabectedin treatment increased the generation of ROS in both breast cancer cells. We have shown that trabectedin causes selective activation of extrinsic and intrinsic apoptotic pathways in two genotypically different breast cancer cells. This preliminary data might guide clinicians to choose appropriate combination agents with trabectedin based on different molecular subtypes of breast cancer.

Anticancer activity of ruthenium(II) arene complexes bearing 1,2,3,4-tetrahydroisoquinoline amino alcohol ligands

Ruthenium complexes offer potential reduced toxicity compared to current platinum anticancer drugs. 1,2,3,4-tetrahydrisoquinoline amino alcohol ligands were synthesised, characterised and coordinated to an organometallic Ru(II) centre. These complexes were evaluated for activity against the cancer cell lines MCF-7, A549 and MDA-MB-231 as well as for toxicity in the normal cell line MDBK. They were observed to be moderately active against only the MCF-7 cells with the best IC₅₀ value of 34 μM for the cis-diastereomeric complex C4. They also displayed excellent selectivity by being relatively inactive against the normal MDBK cell line with SI values ranging from 2.3 to 7.4.

Synthesis, anti-breast cancer activity, and molecular modeling of some benzothiazole and benzoxazole derivatives

A new series of benzothiazoles and benzoxazoles was synthesized using 4-benzothiazol-2-yl-phenylamine and 4-benzoxazol-2-yl-phenylamine as starting materials. All the prepared compounds were evaluated for their antitumor activities against human breast cancer cell lines, MCF-7 and MDA-231, using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) cell viability analysis. Almost all the tested compounds revealed potent antitumor activity, especially the N-methyl piperazinyl substituted derivatives 6f and 6c, which displayed the most potent inhibitory activity with IC50 values ranging from 8 to 17 nM. Docking the synthesized compounds into the epidermal growth factor receptor (EGFR), which is highly expressed in breast cancer, was employed to explore the possible interactions of these compounds with the EGFR. The activity of the reported compounds supports its clinical promise as a component of therapeutic strategies for cancer, for which high concentrations of chemotherapeutic agents are always a major limitation.

Design, synthesis and in vitro anticancer evaluation of a stearic acid-based ester conjugate

AIM

Chemical synthesis and characterization of a lipophilic ester conjugate, propofol stearate and evaluation of its anticancer efficacy on human breast cancer cell lines MDA-MB-361, MCF-7 and MDA-MB-231.

MATERIALS AND METHODS

The chemical structure of the synthesized conjugate was characterized by spectroscopic studies. Its anticancer potential was evaluated on the basis of growth inhibition, cancer cell adhesion and migration and apoptosis induction.

RESULTS

Propofol stearate exhibited significant (p<0.05) growth inhibition of breast cancer cells in a concentration-dependent manner. MDA-MB-231 cells showed highest susceptibility towards the inhibitory effect of the conjugate. Moreover, treatment of MDA-MB-231 cancer cells with 25 μM propofol stearate potentially suppressed their adhesion (~34%) and migration (~41%), and induced apoptosis (~25%).

CONCLUSION

Exogenously-applied stearic acid as an ester derivative, inhibits the growth of human breast cancer cells and shows a beneficial role in the treatment of breast cancer, in vitro.

Preparation and controlled-release studies of a protocatechuic acid-magnesium/aluminum-layered double hydroxide nanocomposite

In the study reported here, magnesium/aluminum (Mg/Al)-layered double hydroxide (LDH) was intercalated with an anticancer drug, protocatechuic acid, using ion-exchange and direct coprecipitation methods, with the resultant products labeled according to the method used to produce them: "PANE" (ie, protocatechuic acid-Mg/Al nanocomposite synthesized using the ion-exchange method) and "PAND" (ie, protocatechuic acid-Mg/Al nanocomposite synthesized using the direct method), respectively. Powder X-ray diffraction and Fourier transform infrared spectroscopy confirmed the intercalation of protocatechuic acid into the inter-galleries of Mg/Al-LDH. The protocatechuic acid between the interlayers of PANE and PAND was found to be a monolayer, with an angle from the z-axis of 8° for PANE and 15° for PAND. Thermogravimetric and differential thermogravimetric analysis results revealed that the thermal stability of protocatechuic acid was markedly enhanced upon intercalation. The loading of protocatechuic acid in PANE and PAND was estimated to be about 24.5% and 27.5% (w/w), respectively. The in vitro release study of protocatechuic acid from PANE and PAND in phosphate-buffered saline at pH 7.4, 5.3, and 4.8 revealed that the nanocomposites had a sustained release property. After 72 hours incubation of PANE and PAND with MCF-7 human breast cancer and HeLa human cervical cancer cell lines, it was found that the nanocomposites had suppressed the growth of these cancer cells, with a half maximal inhibitory concentration of 35.6 μg/mL for PANE and 36.0 μg/mL for PAND for MCF-7 cells, and 19.8 μg/mL for PANE and 30.3 μg/mL for PAND for HeLa cells. No half maximal inhibitory concentration for either nanocomposite was found for 3T3 cells.

The apoptotic effects of sirtuin1 inhibitor on the MCF-7 and MRC-5 cell lines

Sirtuin1 (SIRT1) is an enzyme that deacetylates histones and several nonhistone proteins including p53 during stress and plays an important role in the survival of tumor cells. Hereby, this study describes the potency of salermide as a SIRT1 inhibitor to induce apoptosis in the MCF-7 and MRC-5 cell lines. MCF7 and MRC-5 cell lines were cultured in RPMI-1640 and treated with or without salermide at concentration of 80.56 μmol/L, based on the half-maximal inhibitory concentration (IC50) index at different times (24, 48 and72 h). The IC50 value was established for the salermide in MCF-7. The percentage of apoptotic cells was measured by flow cytometry. Real-time quantitative RT-PCR was performed to estimate the mRNA expression of sirtuin1 in MCF-7 and MRC-5 with salermide at different times. ELISA and Bradford protein techniques were used to detect endogenous levels of total and acetylated p53 protein generated in MCF-7 and MRC-5 cells. Our findings indicated that salermide can induce apoptosis in MCF-7 significantly more effective than MRC-5 cells. We showed that the expression of SIRT1 was dramatically down-regulated by increasing the time of salermide treatment in MCF-7 but not MRC-5 and that the acetylated and total p53 protein levels were increased more in MCF-7 than MRC-5. Salermide, by decreasing the expression of sirtuin1 gene, can induce acetylation of P53 protein and consequently induce significant cell death in MCF-7 that was well tolerated in MRC-5.

Apoptosis Induced by 13-S-hydroxyoctadecadienoic acid in the Breast Cancer Cell Lines, MCF-7 and MDA-MB-231

Objective(s) : The 15-Lipoxygenase-1(15-LOX-1) pathway has become of considerable interest as a promising molecular approach for the modulation of cancer cell growth. 13-S-hydroxyoctadecadienoic acid (13(S)-HODE) is a main metabolite of 15-LOX-1 which is proposed to influence the cancer cell's growth. This study aims to investigate the role of 13(S)-HODE in the regulation of cell growth and apoptosis in the breast cancer cell lines. Materials and Methods : MTT assay was used to examine the cytotoxic effect of 13(S)-HODE in the breast cancer cells, MCF-7 and MDA-MB-231.Annexin-V-FITC staining and cell cycle analysis were performed using flow cytometry. The effect of 13(S)-HODE on the expression level of Peroxisome proliferator-activated receptors-δ (PPAR-δ) was also evaluated. Results : The results demonstrated that 13(S)-HODE inhibited cell growth in a dose and time dependant manner in MCF-7 and MDA-MB-231 cell lines. The reduction of cell growth was associated with the induction of cell cycle arrest and apoptosis in the breast cancer cell lines. Moreover, PPAR-δ was down-regulated in response to 13(S)-HODE administration.

CONCLUSION

This study conducted evidences in to the stimulatory effect of 13(S)-HODE on the inhibition of cell growth and induction of apoptosis in the breast cancer cell lines.

Apoptosis Induced by 13-S-hydroxyoctadecadienoic acid in the Breast Cancer Cell Lines, MCF-7 and MDA-MB-231

Objective(s) : The 15-Lipoxygenase-1(15-LOX-1) pathway has become of considerable interest as a promising molecular approach for the modulation of cancer cell growth. 13-S-hydroxyoctadecadienoic acid (13(S)-HODE) is a main metabolite of 15-LOX-1 which is proposed to influence the cancer cell's growth. This study aims to investigate the role of 13(S)-HODE in the regulation of cell growth and apoptosis in the breast cancer cell lines. Materials and Methods : MTT assay was used to examine the cytotoxic effect of 13(S)-HODE in the breast cancer cells, MCF-7 and MDA-MB-231.Annexin-V-FITC staining and cell cycle analysis were performed using flow cytometry. The effect of 13(S)-HODE on the expression level of Peroxisome proliferator-activated receptors-δ (PPAR-δ) was also evaluated. Results : The results demonstrated that 13(S)-HODE inhibited cell growth in a dose and time dependant manner in MCF-7 and MDA-MB-231 cell lines. The reduction of cell growth was associated with the induction of cell cycle arrest and apoptosis in the breast cancer cell lines. Moreover, PPAR-δ was down-regulated in response to 13(S)-HODE administration.

CONCLUSION

This study conducted evidences in to the stimulatory effect of 13(S)-HODE on the inhibition of cell growth and induction of apoptosis in the breast cancer cell lines.

Cytotoxic effect of novel dehydroepiandrosterone derivatives on different cancer cell lines

The aim of this study was to determine the cytotoxic effect of human cancer cells on three series of novel dehydroepiandrosterone derivatives containing triazole or pyrazole rings at C-17 and an ester moiety at C-3 of the androstane skeleton. The panel cancer cells used in this study were the following: PC-3, MCF-7 and SKLU-1. The results from this study indicated that the steroidal derivatives 4a-4e and 4f-4k showed the highest cytotoxic potency. This difference in this activity could be attributed to the ability of the triazole (three nitrogen atoms) to form stronger hydrogen bonds with the active site of the cell as compared to the pyrazole group having two nitrogen atoms. Compounds 4f-4k having an aromatic ester at C-3 showed an enhanced cytotoxic activity as compared to their aliphatic counterparts 4a-4e. Apparently the electronegative phenyl ring increased the polarity of the molecule, thus increasing the dipole-dipole association of the steroidal molecule with the reactive site of the cell.

Autophagy-dependent EIF2AK3 activation compromises ursolic acid-induced apoptosis through upregulation of MCL1 in MCF-7 human breast cancer cells

Ursolic acid (UA) is a pentacyclic triterpenoid with promising cancer chemopreventive properties. A better understanding of the mechanisms underlying anticancer activity of UA is needed for further development as a clinically useful chemopreventive agent. Here, we found that both endoplasmic reticulum (ER) stress and autophagy were induced by UA in MCF-7 human breast cancer cells. Surprisingly, ER stress was identified as an effect rather than a cause of UA-induced autophagy. Autophagy-dependent ER stress protected the cells from UA-induced apoptosis through EIF2AK3-mediated upregulation of MCL1. Activation of MAPK1/3 but not inhibition of MTOR pathway contributed to UA-induced cytoprotective autophagy in MCF-7 cells. Our findings uncovered a novel cellular mechanism involved in the anticancer activity of UA, and also provided a useful model to study biological significance and mechanisms of autophagy-mediated ER stress.

Evaluation of cytotoxic effects of several novel tetralin derivatives against Hela, MDA-MB-468, and MCF-7 cancer cells

Background:

The inhibitors of the enzymes estrone sulfatase and 17-β-hydroxysteroid dehydrogenase (17-β-HSD) could provide a means of blocking estrogen biosynthesis leading to regression of estrogen-dependent tumors. We evaluated the cytotoxicity of several tetralin derivatives, 2-(4-halo-phenylmethylene)-3,4-dihydronaphthalene-1-ones, as potential inhibitors of these two enzymes, on Hela, MDA-MB-468, and MCF-7 cancer cell lines.

Materials and Methods:

The cell lines were cultured in RPMI medium and the cytotoxic effect of tested compounds (compounds 1 to 5) was screened at the concentrations of 0.1, 1, and 10 μM either alone or in combination with doxorubicin (100 μM), using MTT assay. The mixtures of cell suspension with solvent (1% DMSO in PBS) and doxorubicin (100 μM) were used as negative and positive controls, respectively. Each concentration of compounds was assayed in four wells and repeated in at least three independent experiments for each cell line. The cytotoxic effect of each particular concentration of tested compounds was expressed as the percent of cell survival.

Results:

None of the compounds exhibited cytotoxic effect (reduction of cell survival to less than 50%) on tested cell lines. However, statistically significant reduction in cell survival was observed for some compounds against particular cell lines. Among all tested combinations of compounds with doxorubicin against cell lines, only compound 4 at 10 μM concentration showed synergistic cytotoxic effect with doxorubicin against Hela cells.

Conclusion:

With the exception of compound 2, other tested compounds have potential for further cytotoxicity evaluation. Synthesizing other tetralin derivatives similar to compound 4 and studying their structure-activity relationships (SARs) would be encouraged.

Hippuric acid nanocomposite enhances doxorubicin and oxaliplatin-induced cytotoxicity in MDA-MB231, MCF-7 and Caco2 cell lines

Background

The aim of the current study is to design a new nanocomposite for inducing cytotoxicity of doxorubicin and oxaliplatin toward MDA-MB231, MCF-7, and Caco2 cell lines. A hippuric acid (HA) zinc layered hydroxide (ZLH) nanocomposite was synthesized under an aqueous environment using HA and zinc oxide (ZnO) as the precursors.

Methods

The hippuric acid nanocomposite (HAN) was prepared by the direct reaction of a HA solution with an aqueous suspension of ZnO.

Results

The basal spacing of the nanocomposite was 21.3 Å, which is average of four harmonics at 2θ = 8.32°, 12.50°, 16.68°, and 20.84°. This result indicates that the hippurate anion was successfully intercalated into the interlayer space of ZLH. The combinations of HAN with chemotherapy (drugs) has inhibited the cell growth of the MDA-MB231, MCF-7, and Caco2 cancer cells when compared to drugs alone. An IC₅₀ value for the combination of HAN with doxorubicin toward MCF-7 is 0.19 ± 0.15 μg/mL and toward MDA-MB231 is 0.13 ± 0.10 μg/mL. Similarly, the IC₅₀ for the combination of HAN with oxaliplatin toward Caco2 is 0.24 ± 0.11 μg/mL. In the antiproliferative results, the equal combination of HAN (0.5 μg/mL) with doxorubicin (0.5 μg/mL) has reduced the cell proliferation in MCF-7 and MDA-MB-231 cells into 37.3% and 17.6%, respectively after 24 hours. Similarly, the antiproliferation percentage for equal combination HAN with oxaliplatin (5.00 μg/mL) toward Caco2 is 72.7% after 24 hours.

Conclusion

The resulting combination HAN with drugs has exhibited higher inhibition in cells growth in all cancer cell lines.

In vitro changes in mitochondrial potential, aggresome formation and caspase activity by a novel 17-β-estradiol analogue in breast adenocarcinoma cells

2-Methoxyestradiol, a natural metabolite of estradiol, exerts antiproliferative and antitumour properties in vitro and in vivo. Because of its low oral bioavailability, several promising analogues of 2-methoxyestradiol have been developed. In this study, the in vitro influence of the compound, 2-ethyl-3-O-sulphamoyl-estra-1,3,5(10)16-tetraene (C19), a non-commercially available 17-β-estradiol analogue, was tested on the breast adenocarcinoma MCF-7 cell line. The in vitro influence of 24 h exposure to 0.18 μM of C19 on MCF-7 cells was evaluated on cell morphology, cell cycle progression and possible induction of apoptosis and autophagy. Polarization-optical transmitted light differential interference contrast and fluorescence microscopy revealed the presence of cells blocked in metaphase, occurrence of apoptotic bodies and compromised cell density in C19-treated cells. Hallmarks of autophagy, namely an increase in the number of acidic vacuoles and lysosomes, were also observed in C19-treated samples. An increase in the number of cells present in the sub-G1 fraction, as well as a reduction in mitochondrial membrane potential was observed. No significant alterations in caspase 8 activity were observed. A twofold increase in aggresome formation was observed in C19-treated cells. C19 induced both apoptosis and autophagy in MCF-7 cells.

Calyculin A from Discodermia calyx is a dual action toxin that blocks calcium influx and inhibits protein Ser/Thr phosphatases

Calyculin A (Caly A) is cell permeable toxin widely used in cell biology research as an inhibitor of type 1 and type 2A protein Ser/Thr phosphatases of the PPP family. Here we tested effects of low concentrations of Caly A on proliferation of human cancer and non-cancer cell lines. We found that long-term 0.3 nM Caly A prevented G1 to S phase cell cycle progression in human Hs-68 fibroblasts and ARPE19 epithelial cells, but not human breast cancer MDA-MB-468, MDA-MB-231 and MCF7 cells. These conditions produced no change in cyclin D1 levels or in the phosphorylation of endogenous proteins. However, acute application of 0.3 nM Caly A blocked serum-induced increase in intracellular calcium levels in Hs-68 fibroblasts, but not in MDA-MB-468 breast cancer cells. We propose that subnanomolar Caly A prevents cell cycle progression because it blocks calcium uptake by fibroblasts. This probably involves non-selective cation channels and cancer cell proliferation was not affected because calcium enters these cells by other channels. Our results suggest that calyculin A has dual actions and acts as a channel blocker, in addition to its well-established effects as a phosphatase inhibitor.

Heterogeneity of breast cancer stem cells as evidenced with Notch-dependent and Notch-independent populations

Studies have suggested the potential importance of Notch signaling to the cancer stem cell population in some tumors, but it is not known whether all cells in the cancer stem cell fraction require Notch activity. To address this issue, we blocked Notch activity in MCF-7 cells by expressing a dominant-negative MAML-GFP (dnMAML) construct, which inhibits signaling through all Notch receptors, and quantified the effect on tumor-initiating activity. Inhibition of Notch signaling reduced primary tumor sphere formation and side population. Functional quantification of tumor-initiating cell numbers in vivo showed a significant decrease, but not a complete abrogation, of these cells in dnMAML-expressing cells. Interestingly, when assessed in secondary assays in vitro or in vivo, there was no difference in tumor-initiating activity between the dnMAML-expressing cells and control cells. The fact that a subpopulation of dnMAML-expressing cells was capable of forming primary and secondary tumors indicates that there are Notch-independent tumor-initiating cells in the breast cancer cell line MCF-7. Our findings thus provide direct evidence for a heterogeneous cancer stem cell pool, which will require combination therapies against multiple oncogenic pathways to eliminate the tumor-initiating cell population.

Anti-Cancer Effect of 3-(4-dimethylamino phenyl)-N-hydroxy-2-propenamide in MCF-7 Human Breast Cancer

OBJECTIVES

In recent years, a number of structurally diverse Histone deacetylase (HDAC) inhibitors have been identified and these HDAC inhibitors induce growth arrest, differentiation and/or apoptosis of cancer cells in vitro and in vivo. This study aimed at investigating the anti-tumor activity of newly synthesized HDAC inhibitor, 3-(4-dimethylamino phenyl)-N-hydroxy-2-propenamide (IN-2001) using human breast cancer cells.

METHODS

We have synthesized a new HDAC inhibitor, IN-2001, and cell proliferation inhibition assay with this chemical in estrogen receptor-positive human breast cancer MCF-7 cells. Cell cycle analysis on MCF-7 cells treated with IN-2001 was carried out by flow cytometry and gene expression was measured by RT-PCR.

RESULTS

In MCF-7 cells IN-2001 showed remarkable anti-proliferative effects in a dose- and time-dependent manner. In MCF-7 cells, IN-2001 showed a more potent growth inhibitory effect than that of suberoylanilide hydroxamic acid. These growth inhibitory effects were related to the cell cycle arrest and induction of apoptosis. IN-2001 showed accumulation of cells at G(2)/M phase and of the sub-G(1) population in a time-dependent manner, representing apoptotic cells. IN-2001-mediated cell cycle arrest was associated with HDAC inhibitor-mediated induction of CDK inhibitor expression. In MCF-7 cells, IN-2001 significantly increased p21(WAF1) expression.

CONCLUSIONS

In summary, cyclin-dependent kinase (CDK) induced growth inhibition, possibly through modulation of cell cycle and apoptosis regulatory proteins, such as CDK inhibitors, and cyclins. Taken together, these results provide an insight into the utility of HDAC inhibitors as a novel chemotherapeutic regime for hormone-sensitive and insensitive breast cancer.

Soy isoflavone extracts stimulate the growth of nude mouse xenografts bearing estrogen-dependent human breast cancer cells (MCF-7)

We explored the effects of different lifetime exposures to soy isoflavone extracts on the growth of estrogen-dependent human breast cancer cells (MCF-7) implanted into athymic mice of different ovarian statuses. The athymic mice, ovariectomized or not, were implanted with MCF-7 cells. Mice were fed with low, moderate and high doses of soy isoflavone extract, at dietary concentrations of 6.25, 12.5 and 25 g/kg, in different reproductive models, respectively. The expression of ki-67 was detected by immunohistochemistry. pS2 expression in tumors was analyzed by real-time PCR. Estrogen level in the serum was measured by chemiluminescence enzyme immunoassay. Total genistein and daidzein levels in serum and urine were determined by liquid chromatography-electrospray tandem mass spectrometry (LC-ES/MS/MS). In Group A, on week 4, nude mice were exposed to different doses of soy iosflavone extracts. In Group B, the experimental diets were given to the nude mice following ovariectomy and tumor implantation. In both groups, 6.25 and 12.5 g/kg soy isoflavone extracts stimulated the growth of MCF-7 xenografts, increased pS2 expression, proliferation and estrogen level in serum. In both Group B (postmenopausal mouse model) and Group C (premenopausal mouse model), soy isoflavone extracts at doses of 6.25 and 12.5 g/kg showed stimulatory effects on the growth of MCF-7 tumors. In conclusion, administration of soy isoflavone extracts at doses of 6.25 and 12.5 g/kg during adolescence or later in life stimulated tumor growth in both menopausal and postmenopausal mouse models.

Monitoring of the Zeta Potential of Human Cells upon Reduction in Their Viability and Interaction with Polymers

The dynamic light scattering (DLS) technique was applied in order to assess the zeta potential of the plasma membrane of human cells. At pH 7.4, the cell zeta potential for different types of cells showed variations over a wide range and was equal to -19.4 ± 0.8 mV for HeLa cells and -31.8 ± 1.1 mV for erythrocytes. The difference could presumably be attributed to the differences in the biochemical composition of the cell plasma membrane. As a result of the heating of HeLa cells, the zeta potential shifted towards more negative voltages by 4.2 mV. An increase in the zeta potential correlated with an increase in the content of phosphatidylserine on the cell surface, which is considered to be an early marker of apoptosis. The DLS technique was also used to study the interactions between the cells and membranotropic polymers, such as polycations and nonionogenic Pluronic L121.

Genotoxic effects of some l-[(benzofuran-2-yl)-phenylmethyl]-imidazoles on MCF-7 cell line

Increased exposure to estrogen has been associated with the risk of breast cancer. Substituted benzofuran derivatives with inhibitory effects on estrogen synthesis could be considered as a potential approach to reduce the risk of breast cancer. The study of cytotoxic effects of these compounds has suggested involvement of other mechanisms such as DNA damage. In the current study we have investigated genotoxic effects of some benzofuran derivatives on MCF-7 cell line. The MCF-7 cell line was exposed both to benzofuran phenylmethyl imidazole and its 4- fluoro, 4-chloro, 2-methoxy and 2-methyl derivatives for 2 h. The Comet assay was used to examine DNA damage due to this exposure. We also studied the DNA repair capacity after 2 h exposure to genotoxic concentrations of these compounds and their recovery were evaluated after 17 and 24 h, using the comet assay. The results indicated that genotoxic effects of these compounds appeared in concentrations of 10(-8) to 10(-6) M. The 4- fluoro and 4-chloro derivatives exhibited the highest genotoxicity and the unsubstituted benzofuran phenylmethyl imidazole had the lowest effect. The 4- fluoro, 4-chloro and 2-methyl derivatives were recovered after 24 h while 2-methoxy and the unsubstituted derivatives were recovered after 17 h. The results showed that these compounds are genotoxic and the concentration of tested benzofuran derivatives with genotoxic effects are not close to their enzyme inhibitory concentration. Moreover, our study shows that the DNA damages are repairable. Therefore, it seems that the investigated compounds have the potentials as therapeutic agents.

Different Expression of Extracellular Signal-Regulated Kinases (ERK) 1/2 and Phospho-Erk Proteins in MBA-MB-231 and MCF-7 Cells after Chemotherapy with Doxorubicin or Docetaxel

OBJECTIVES

Curative treatment of breast cancer patients using chemotherapy often fails as a result of intrinsic or acquired resistance of the tumor to the drug. ERK is one of the main components of the Ras/Raf/MEK/ERK cascade, which mediates signal from cell surface receptors to transcription factors to regulate different gene expression. In this study, cytotoxicity and the expression of Erk1/2 and phospho-ERK was compared in MDA-MB-231 (ER-) and MCF-7 (ER+) cell lines after treatment with doxorubicin (DOX) or docetaxel (DOCT).

MATERIALS AND METHODS

Cell cytotoxicity of DOX or DOCT was calculated using MTT assay. Immonofluorescent technique was used to show MDR-1 protein in MDA-MB-231 and MCF-7 cells after treatment with DOX or DOCT. The expression of ERK1/2 and phpspho-ERK was assayed with immunoblotting.

RESULTS

Comparing IC50 values showed that MDA-MB-231 cells are more sensitive than MCF-7 cells to DOX or DOCT. Immonofluorescent results confirmed the expression of MDR-1 in these two cell lines after DOX or DOCT treatment. In MDA-MB-231 cells the expression of ERK1/2 and phospho-ERK was decreased after DOX treatment in a dose-dependent manner. In contrast in MCF-7 cells the expression of ERK1/2 and phospho-ERK was increased after DOX treatment. DOCT treatment demonstrated the same result with less significant differences than DOX.

CONCLUSION

The heterogeneity seen in cell lines actually reflects the heterogeneity of breast cancers. That is why, patients categorized in one group respond differently to a single treatment. These results emphasize the importance of a more accurate classification and a more specific treatment of breast cancer subtypes.

Antiproliferative activity and induction of apoptosis in estrogen receptor-positive and negative human breast carcinoma cell lines by Gmelina asiatica roots

Low risk of breast cancer has been proposed to be associated with high intake of lignans. We have reported the presence of lignans in Gmelina asiatica roots. There are no scientific reports on the antiproliferative activity of G. asiatica roots. The objective of the present study was to evaluate the effect of ethyl acetate extract from G. asiatica roots (EGAR) on estrogen receptor-positive (MCF-7) and negative (MDA-MB-231) human breast cancer cell lines. The effects of 50% inhibitory concentrations (IC₅₀) of EGAR on MCF-7 and MDA-MB-231 cells were determined using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay kit. The mode of cell death caused by EGAR was determined using dual apoptosis assay kit by observing the cells under fluorescent microscope. The quantification of apoptosis and necrosis in cells caused by EGAR was determined using cell death detection kit through ELISA. Down-regulation of the proliferative activity occurred in a clear dose-dependent response with IC₅₀ values of 32.9 ± 3.8 μg/mL in MCF-7 and 19.9 ± 2.3 μg/mL in MDA-MB-231 cell lines. Treatment of breast cancer cells with EGAR resulted in significant apoptosis. The EGAR contain lignans and flavonoids. The antiproliferative activity of the extract is attributed to the presence of these secondary metabolites. The results suggest the efficacy of G. asiatica roots as antiproliferative agents on human breast cancer cells, supporting the hypothesis that plants containing lignans have beneficial effects on human breast cancer.

Silibinin enhances ultraviolet B-induced apoptosis in mcf-7 human breast cancer cells

Purpose

Chemotherapies for breast cancer generally have strong cellular cytotoxicity and severe side effects. Thus, significant emphasis has been placed on combinations of naturally occurring chemopreventive agents. Silibinin is a major bioactive flavonolignan extracted from milk thistle with chemopreventive activity in various organs including the skin, prostate, and breast. However, the mechanism underlying the inhibitory action of silibinin in breast cancer has not been completely elucidated. Therefore, we investigated the effect of silibinin in MCF-7 human breast cancer cells and determined whether silibinin enhances ultraviolet (UV) B-induced apoptosis.

Methods

The effects of silibinin on MCF-7 cell viability were determined using the MTT assay. The effect of silibinin on PARP cleavage, as the hallmark of apoptotic cell death, and p53 protein expression in MCF-7 cells was analyzed using Western blot. The effect of silibinin on UVB-induced apoptosis in MCF-7 cells was analyzed by flow cytometry.

Results

A dose- and time-dependent reduction in viability was observed in MCF-7 cells treated with silibinin. Silibinin strongly induced apoptotic cell death in MCF-7 cells, and induction of apoptosis was associated with increased p53 expression. Moreover, silibinin enhanced UVB-induced apoptosis in MCF-7 cells.

Conclusion

Silibinin induced a loss of cell viability and apoptotic cell death in MCF-7 cells. Furthermore, the combination of silibinin and UVB resulted in an additive effect on apoptosis in MCF-7 cells. These results suggest that silibinin might be an important supplemental agent for treating patients with breast cancer.

Synthesis and Cytotoxic Evaluation of Some Novel SulfonamideDerivativesAgainst a Few Human Cancer Cells

Sulfonamides are the first effective chemotherapeutic agents used for several years to cure or prevent systemic bacterial infections. In addition, this agents showed anti-carbonic anhydrase and cause cell cycle perturbation in the G1 phase, disruption of microtubule assembly, suppression of the transcription activator Nf-Y, angiogenesis and matrix metalloproteinase (MMP). In recent years, novel synthesized sulfonamides have been introduced as antitumor, antiviral and anti-inflammatory agents. In this paper, the cytotoxic effects of 8 synthesized sulfonamides were investigated by MTT assay on HeLa, MDA-MD-468 and MCF-7 cancer cell lines. Human cancer cells were cultured and passaged in RPMI-1640 medium. Cells incubated in 96-well plates in a concentration of 1 × 10(5) cells/mL for 24 h, and then logarithmic concentrations (0.1 μm, 1 μm, 10 μm, 100 μm, 1mM) of each drug were prepared, added to the plates and incubated for 72 h. Cell survival was then determined using ELISA plate reader in 540 nm applying MTT assay. All tested sulfonamides showed cytotoxic effect on HeLa and MCF-7 cells in the concentration range of 100-1000 μm. These sulfonamides were cytotoxic against MDA-MB-468 cell line at a concentration of 10-100 μm and reduced the cell survival less than 50%. According to the results calculated IC50's were as following: MDA-MB-468 < 30 μm; MCF-7 < 128 μm and HeLa< 360 μm. In conclusion, some tested sulfonamides had good cytotoxic effects against breast cancer cells, MDA-MB-468 and further investigations are needed to confirm their effects against other cells.

STAT3 upregulates the protein expression and transcriptional activity of β-catenin in breast cancer

The expression of β-catenin detectable by immunohistochemistry has been reported to be prognostically important in breast cancer. In this study, we investigated the mechanism by which β-catenin is regulated in breast cancer cells. Our analysis of the gene promoter of β-catenin revealed multiple putative STAT3 binding sites. In support of the concept that STAT3 is a transcriptional regulator for β-catenin, results from our chromatin immunoprecipitation studies showed that STAT3 binds to two of the three potential STAT3-binding sites in the gene promoter of β-catenin (-856 and -938). Using our generated MCF-7 cell clones that carry an inducible STAT3C construct, we found that the expression levels of STAT3C significantly correlated with the transcriptional activity of β-catenin. Similar observations were made when we subjected two breast cancer cell lines (MCF-7 and BT-474) to STAT3 knock-down or transient gene transfection of STAT3C. Using immunohistochemistry, we found that pSTAT3 and β-catenin significantly correlated with each other (p=0.003, Fisher's exact test) in a cohort of primary breast tumors (n=129). To conclude, our results support the concept that STAT3 upregulates the protein expression and transcriptional activity of β-catenin in breast cancer, and these two proteins may cooperate with each other in exerting their oncogenic effects in these tumors.