Apoptosis In Human Breast Cancer Research Articles

Sparstolonin B Reduces Estrogen-Dependent Proliferation in Cancer Cells: Possible Role of Ceramide and PI3K/AKT/mTOR Inhibition

Background: The aim of this study was to determine the effect of Sparstolonin B (SsnB) on cell proliferation and apoptosis in human breast cancer (MCF-7) and human ovarian epithelial cancer (OVCAR-3) cell lines in the presence and absence of estradiol hemihydrate (ES). Phosphoinositol-3 kinase (PI3K), phosphorylated protein kinase B alpha (p-AKT), phosphorylated mTOR (mechanistic target of rapamycin) signaling proteins, and sphingomyelin/ceramide metabolites were also measured within the scope of the study. Methods: The anti-proliferative effects of SsnB therapy were evaluated over a range of times and concentrations. Cell proliferation was determined by measuring the Proliferating Cell Nuclear Antigen (PCNA). PCNA was quantified by ELISA and cell distribution was assessed by immunofluorescence microscopy. MTT analysis was used to test the vitality of the cells, while LC-MS/MS was used to analyze the amounts of ceramides (CERs), sphingosine-1-phosphate (S1P), and sphingomyelins (SMs). TUNEL labeling was used to assess apoptosis, while immunofluorescence staining and enzyme-linked immunosorbent assay (ELISA) were used to measure the levels of PI3K, p-AKT, and p-mTOR proteins. Results: Sparstolonin B administration significantly decreased cell viability in MCF-7 and OVCAR-3 cells both in the presence and absence of ES, while it did not cause toxicity in healthy human fibroblasts. In comparison to controls, cancer cells treated with SsnB showed a significant drop in the levels of S1P, PI3K, p-AKT, and p-mTOR. In cancer cells cultured with SsnB, a significant increase in intracellular concentrations of C16-C24 CERs and apoptosis was observed. Conclusions: SsnB downregulated the levels of S1P, PI3K, p-AKT, and p-mTOR while reducing cell proliferation and promoting ceramide buildup and apoptosis.

Cyclin-dependent kinase inhibitors enhance programmed cell death protein 1 immune checkpoint blockade efficacy in triple-negative breast cancer by affecting the immune microenvironment.

Clinical studies on programmed death-ligand 1 (PD-L1) immune checkpoint inhibitors for treating triple-negative breast cancer (TNBC) have shown unsatisfactory efficacy due to low tumor-infiltrating lymphocyte (TIL) levels. Inhibitors targeting cyclin-dependent kinase (CDK) proteins can affect the immune microenvironment, increase TIL levels, and promote antitumor immunity, thus providing a new direction for TNBC treatment strategies. The authors tested three CDK inhibitors on the TNBC cell lines MDA-MB-231 and 4T1 and validated their antitumor effects and impact on the immune microenvironment using multiple detection methods. They verified the efficacy and immune-related mechanisms of different combination therapy experiments in a 4T1 cell-transplanted BALB/c mouse model. Treatment with CDK inhibitors for 72 hours inhibited cell proliferation, clone formation, migration, and cell-cycle arrest and induced apoptosis in human breast cancer MDA-MB-231 cells and mouse breast cancer 4T1 cells. CDK inhibitors suppressed DNA methylation by downregulating DNMT1, DNMT3a, and DNMT3b expression. These three inhibitors promoted the secretion of various chemokines, enhanced tumor cell antigen presentation, and increased PD-L1 expression. CDK inhibitors improved the efficacy of immunotherapy in animal models and increased TIL levels. Combination therapy with CDK and PD-L1 immune checkpoint inhibitors affects the immune microenvironment, promotes antitumor immunity, and improves the efficacy of immunotherapy for TNBC.

Cannabinoids and standardized cannabis extracts inhibit migration, invasion, and induce apoptosis in MCF-7 cells through FAK/MAPK/Akt/NF-κB signaling

BackgroundBreast cancer is the highest incidence of all types of cancer in women, and the cancer metastasis process accounts for a majority of cancer deaths. Two major cannabinoids, Δ-9-tetrahydrocannabinol (THC) and cannabidiol (CBD), from Cannabis sativa are expected to have anti-cancer activity. This study aimed to investigate the effects of THC, CBD, and standardized cannabis extracts (F1, F2, and F3) on migration, invasion, and apoptosis of human breast cancer (MCF-7) cells. MethodsCell viability, survival, and apoptosis were determined using the MTT, clonogenic, and nuclear staining assays, respectively, while cancer cell migration and invasion were evaluated by the wound healing, trans-well, and filopodia assays. Western blot analysis was used to find out the mechanisms of the cannabinoids against MCF-7 cells. ResultsCBD, THC, and F1 inhibited filopodia formation, migration, and invasion of MCF-7 cells through suppressing the expression of the FAK, Akt, ERK1/2, p38MAPKs, and NF-κB upstream pathways, as well as inhibiting the Rac1/Cdc42 downstream pathways. In addition, CBD significantly inhibited the mTOR pathway. Furthermore, CBD and F1 induced apoptosis in MCF-7 cells via the Bcl-2/caspase-3 pathways. ConclusionThese results indicate that THC, CBD, and F1 have great abilities for preventing breast cancer cell metastasis in in vitro experiments.

Induction of oxidative DNA damage, cell cycle arrest and p53 mediated apoptosis by calcium titanate nanoparticles in MCF-7 breast cancer cells

BackgroundThe distinctive properties and high activity of calcium titanate nanoparticles (CaTiO3-NPs) increase their use in many products. However, the cytotoxic and genotoxic effects of CaTiO3-NPs in human cancer cell lines have not been well studied. Therefore, this study was conducted to explore CaTiO3-NPs induced cytotoxicity, genomic instability and apoptosis in human breast cancer (MCF-7) cells.MethodsSulforhodamine B (SRB) and the alkaline comet assays were done to study cell viability and DNA damage induction, respectively. Apoptosis induction and cell cycle distribution were analyzed using flow cytometry. The level of intracellular reactive oxygen species (ROS) was studied, and the expression levels of p53, Bax and Bcl2 genes were also measured.ResultsThe results of the Sulforhodamine B (SRB) cytotoxicity assay showed that viability of MCF-7 cells was not affected by CaTiO3-NPs treatment for 24 h, however, exposure to CaTiO3-NPs for 72 h caused concentrations dependent death of MCF-7 cells. Treatment with CaTiO3-NPs for 72 h caused marked increases in intracellular ROS level and induced DNA damage. Treatment of MCF-7 cells with CaTiO3-NPs also caused MCF-7 cell cycle arrest at the G0 and S phases and s triggered apoptosis of MCF-7 cells by causing simultaneous increases in the expression levels of apoptotic p53 and Bax genes and a decrease in the expression level of anti-apoptotic Bcl2 gene.ConclusionCollectively, it was concluded that CaTiO3-NPs cause time- and concentration-dependent cytotoxic effects in human MCF-7 cells through induction of ROS generation, genomic instability and apoptosis. Thus it is recommended that further in vitro and in vivo studies are therefore recommended to understand the cytotoxic and biological effects of CaTiO3-NPs.

Interaction between moxifloxacin and Mcl-1 and MITF proteins: the effect on growth inhibition and apoptosis in MDA-MB-231 human triple-negative breast cancer cells

BackgroundMicrophthalmia-associated transcription factor (MITF) activates the expression of genes involved in cellular proliferation, DNA replication, and repair, whereas Mcl-1 is a member of the Bcl-2 family of proteins that promotes cell survival by preventing apoptosis. The objective of the present study was to verify whether the interaction between moxifloxacin (MFLX), one of the fluoroquinolones, and MITF/Mcl-1 protein, could affect the viability, proliferation, and apoptosis in human breast cancer using both in silico and in vitro models.MethodsMolecular docking analysis (in silico), fluorescence image cytometry, and Western blot (in vitro) techniques were applied to assess the contribution of MITF and Mcl-1 proteins in the MFLX-induced anti-proliferative and pro-apoptotic effects on the MDA-MB-231 breast cancer cells.ResultsWe indicated the ability of MFLX to form complexes with MITF and Mcl-1 as well as the drug’s capacity to affect the expression of the tested proteins. We also showed that MFLX decreased the viability and proliferation of MDA-MB-231 cells and induced apoptosis via the intrinsic death pathway. Moreover, the analysis of the cell cycle progression revealed that MFLX caused a block in the S and G2/M phases.ConclusionsWe demonstrated for the first time that the observed effects of MFLX on MDA-MB-231 breast cancer cells (growth inhibition and apoptosis induction) could be related to the drug’s ability to interact with MITF and Mcl-1 proteins. Furthermore, the presented results suggest that MITF and Mcl-1 proteins could be considered as the target in the therapy of breast cancer.Graphical abstract

Induction of p53 mediated mitochondrial apoptosis and cell cycle arrest in human breast cancer cells by plant mediated synthesis of silver nanoparticles from Bergenia ligulata (Whole plant)

The biological synthesis of nanoparticles is a growing research trend because it has numerous pharmaceutical and biomedical applications. The present study describes the preparation, characterization and anti-cancer evaluation of silver nanoparticles synthesized using an aqueous extract of Bergenia ligulata whole plant as a reducing agent. The physiochemical properties of the Bergenia ligulata silver nanoparticles (BgAgNPs) were measured by ultraviolet–visible spectrophotometry, Fourier transform infrared spectrophotmetry (FTIR), X-ray powder diffraction (XRD) and Scanning electron microscopy (SEM) analysis for identifying functional groups, crystallinity, structural and morphological features, respectively. Further, BgAgNps, along with the Bergenia ligulata aqueous extract (BgAE), were investigated for their effects on cell proliferation and apoptosis through MTT, colony-forming assay, wound-healing assay and flow cytometry-based approaches. The cytotoxic effects were more pronounced in cells treated with BgAgNps in comparison to BgAE. These effects were evidenced by the decreasing cell viability, migration capacity and loss of characteristic morphological features. In addition, BgAgNps unveiled significant induction of apoptosis in human breast cancer (MCF-7) cells, possibly through oxidative stress-mediated reactive oxygen species (ROS) generation and loss of mitochondrial membrane potential (MMP). Moreover, molecular mechanism-based studies revealed that BgAgNps robustly augmented p53 levels and pro-apoptotic downstream targets of p53 like Bax and cleaved caspase 3 in MCF-7 cells. Of note, BgAgNps had little or no cytotoxic effect on p53-deficient cancer cells (Mda-mb-231 and SW-620). These findings confirm that the BgAgNPs exhibited superior anti-cancer potential and could be exploited as a promising, cost-effective, and environmentally benign strategy in treating this disease in the future.

Ursolic Acid Derivative UA232 Promotes Tumor Cell Apoptosis by Inducing Endoplasmic Reticulum Stress and Lysosomal Dysfunction.

Due to increased drug and radiation tolerance, there is an urgent need to develop novel anticancer agents. In our previous study, we performed a series of structural modifications of ursolic acid (UA), a natural product of pentacyclic triterpenes, and found UA232, a derivative with stronger anti-tumor activity. In vitro experiments showed that UA232 inhibited proliferation, induced G0/G1 arrest, and promoted apoptosis in human breast cancer and cervical cancer cells. Mechanistic studies revealed that UA232 promoted apoptosis and induced protective autophagy via the protein kinase R-like endoplasmic reticulum kinase/activating transcription factor 4/C/EBP homologous protein-mediated endoplasmic reticulum stress. In addition, we also found that UA232 induced lysosomal biogenesis, increased lysosomal membrane permeability, promoted lysosomal protease release, and led to lysosome-dependent cell death. Furthermore, UA232 suppressed tumor growth in a mouse xenograft model. In conclusion, our study revealed that UA232 exerts multiple pharmacological effects against breast and cervical cancers by simultaneously triggering endoplasmic reticulum stress and lysosomal dysfunction. Thus, UA232 may be a promising drug candidate for cancer treatment.

Differential effects of phenolic extracts from red-fleshed apple peels and flesh induced G1 cell cycle arrest and apoptosis in human breast cancer MDA-MB-231 cells.

Red-fleshedapples are preferredbecause of their high content of phenolics and antioxidants in peel and pulp. Herein, we evaluated the mechanisms of apple peel polyphenolic extracts (APP) and apple flesh polyphenolic extracts (AFP) from the new red-fleshed apple in inhibiting cell proliferation and inducing apoptosis on human breast cancer MDA-MB-231 cells. The antiproliferative activities were determined by the CCK8 assay. The expression of proteins was determined using Western blot. We found that the content of polyphenols and flavonoids in APP was significantly higher than that in AFP, and 14 main phenolic compounds in APP and AFP were quantified using UPLC-MS/MS techniques. Besides, the significant inhibition effects of APP and AFP were achieved through Akt pathway by inducing apoptosis (significantly upregulating reactive oxygen species [ROS] levels, and downregulating expression of pAkt, pBad, Bcl-2, promoting Cytochrome c release, activating Cle-Caspase 9, and inducing expressions of Cle-Caspase 3 and Cle-PARP), and inducing G0/G1 cell cycle arrest (increased expressions of p-p53 and p21 and decreased expressions of PCNA and Cyclin D1). And the inhibition effect of APP was stronger than that of AFP. These results suggest that AFP and APP may be excellent sources of natural chemicals for treating triple-negative breast cancer MDA-MB-231 cells. PRACTICAL APPLICATION: The effects of antiproliferation of phenolic extracts from red-fleshed apple peels and flesh on human breast cancer MDA-MB-231 cells were evaluated. The data may clarify the functional parts of red-fleshed apple and provide some basis for scientific researchers and consumers to recognize and exploit red-fleshed apple.

Retraction.

Retraction: "Effects of RNA interference-mediated silencing of toll-like receptor 4 gene on proliferation and apoptosis of human breast cancer MCF-7 and MDA-MB-231 cells: An in vitro study," by Xiao-Ling Gao, Jiao-Jiao Yang, Shu-Juan Wang, Yan Chen, Bei Wang, Er-Jing Cheng, Jian-Nan Gong, Yan-Ting Dong, Dai Liu, Xiang-Li Wang, Ya-Qiong Huang, Dong-Dong An, J Cell Physiol. 2019; 433-442: The above article, published online on 22 June 2018 in Wiley Online Library (https://onlinelibrary.wiley.com/doi/10.1002/jcp.26573) has been retracted by agreement between the journal's Editor in Chief, Prof. Dr. Gregg Fields, and Wiley Periodicals LLC. The retraction has been agreed following an investigation based on allegations raised by a third party. A detailed investigation revealed that several image elements of the experimental data were published elsewhere in a different scientific context. Thus, the editors consider the conclusions of this article to be invalid.

Low-temperature extracts of Purple blossoms of basil (Ocimum basilicum L.) intervened mitochondrial translocation contributes prompted apoptosis in human breast cancer cells

BackgroundThe preventive and therapeutic medical utilization of this plant is an age-long practice across the globe. This study aimed to validate the impact of dark purple blossoms of basil (Ocimum basilicum L.) aqueous extract at low temperature (0 °C) mediated mitochondrial fission contributed to induced apoptosis in human breast cancer cells.MethodsFresh blossoms were extracted at low temperature (0 °C) using a watery solvent. Human MCF7 breast cancer cells were then treated with 3 separate fluctuated concentrations of 0, 50, 150 and 250 µg/mL for 24 and 48 h.ResultsThe outcomes demonstrated the presence of anthocyanins, anthraquinones, tannins, reducing sugars, glycosides, proteins, amino acids, flavonoids and volatile oils and nonappearance of Terpinoids and alkaloids. Contrastingly, frail presence of steroids in basil blossoms aqueous concentrate was noted. In addition, the results from a phytochemical subjective examination of basil (Ocimum basilicum L.) blossoms aqueous extract demonstrated that most of the credited natural impacts containing more remarkable contents of antioxidants and anticancer compounds in basil blossoms aqueous extract. Moreover, the restraint of glucose take-up was alleviated mediated by a dose-dependent manner in MCF7 cells with basil (Ocimum basilicum L.) blossoms aqueous extract inducted for 24 h, resulting in mitochondrial fission.ConclusionThis is the first study that shows the impact of the aqueous extract of basil (Ocimum basilicum L.) blossoms was extracted at low temperature (0℃/6 h) underlined high amounts of flavonoids and phenolic compounds bearing more anticancer and antioxidant activities compared to another aqueous extract (using boiled water solvent) and alcoholic extracts.

Phenolic Extract of Seagrass, Halophila ovalis Activates Intrinsic Pathway of Apoptosis in Human Breast Cancer (MCF-7) Cells

The marine ecosystem is considered as a treasure of numerous novel biologically active molecules. We investigated the anticancer potential of the phenolic extract of Halophila ovalis in breast cancer (MCF-7) cells and characterized the possible underlying molecular mechanism. The phenolic extract (5 µl) of H. ovalis effectively inhibited the growth of MCF-7 cells. The results of DAPI staining indicated that this phenolic extract potently induces apoptosis in MCF-7 cells which was observed by increased chromatin condensation in the treated cells. An increased expression of the active fragments of an executioner caspase, caspase 3 in phenolic extract-treated MCF-7 cells further confirms this apoptosis induction. In consequence, the loss of mitochondrial membrane potential was noticed in treated cells. The protein expression analyzes show decreased expression of the anti-apoptotic protein, Bcl-2, and DNA repair enzyme, PARP in treated cells indicating the probable molecular targets of apoptosis. Further, the phenolic extract of H. ovalis blocked the antioxidant defense system in MCF-7 cells by down-regulating the protein expression of a major transcription factor, Nrf-2 and regulatory antioxidant enzymes, SOD-2 and HO-1. These results show the presence of chemopreventive compound(s) in the phenolic extract, which offers a platform for future studies to identify the active principles.

Corn Silk (Zea mays L.) Induced Apoptosis in Human Breast Cancer (MCF-7) Cells via the ROS-Mediated Mitochondrial Pathway.

Cancer has been recognized as one of the life-threating diseases. Breast cancer is a leading cause of mortality among women. In spite of current developments in the therapy and diagnosis of cancer, the survival rate is still less. Recently, plant-derived natural products gain attention as anticancer agents due to the nontoxic nature. Therefore, the aim of present study was to investigate the anticancer capacity of corn silk extract (CSE) on human breast cancer (MCF-7) and normal human mesenchymal (hMSC-TERT4) cells. Following 24 h treatment to corn silk extract, the cytotoxicity was assessed by MTT, NRU, and morphological assays. The oxidative stress markers (GSH and LPO), ROS production, MMP change, and expression of apoptotic marker genes (p53, Bax, Bcl-2, caspase-3, and caspase-9) were also studied in MCF-7 cells treated at 250 to 1000 μg/ml of CSE for 24 h. Our results showed that CSE decreased the cell viability and increased the apoptosis in a dose-dependent manner. The level of LPO and ROS production was found significantly higher; however, GSH and MMP level was observed lower in CSE-treated MCF-7 cells. The real-time PCR data showed a significant upregulation in p53, Bax, caspase-3, and caspase-9 and downregulation in the mRNA expression of Bcl-2 genes in MCF-7 cells exposed to CSE. Collectively, the data from this study stated that corn silk extract induced apoptosis via the ROS-mediated mitochondrial pathway in MCF-7 cells.

MicroRNA‑192 inhibits cell proliferation and induces apoptosis in human breast cancer by targeting caveolin 1.

It has been demonstrated that microRNA-192 (miR-192) serves important roles in different cancer types, including breast cancer, prostate cancer and colorectal cancer. However, its biological role and function in breast cancer remains largely unknown. The present study aimed to determine the role of miR-192 in breast cancer. In the present study, one normal breast and two breast tumor cells lines were used, which included the normal mammary fibroblast cell line Hs578Bst, a more aggressive breast tumor cell line MDA-MB-231 and a less aggressive breast tumor cell line MCF-7. The effect of miR-192 on proliferation of breast cancer cells was detected with an MTT assay. Western blot analysis was performed to determine protein expression of caveolin 1 (CAV1). A lentiviral vector that overexpresses pre-miR-192 and control lentiviral packaging plasmids were used in the present study. The Student's t-test was performed to analyze the significance of differences between samples. In the present study, it was determined that the expression of miR-192 is downregulated in breast cancer, compared with the adjacent normal tissues. Overexpression of miR-192 significantly inhibited cell proliferation, and induced cell apoptosis and cell cycle arrest in MCF7 and MDA-MB-231 cells. Using a bioinformatics method, CAV1 was considered a potential target of miR-192. Furthermore, it was demonstrated that CAV1 is a direct target of miR-192 and its protein expression is negatively regulated by miR-192. Therefore, the present study demonstrated that miR-192 serves an important role as a regulator in breast cancer and the miR-192/CAV1 axis has a potential as a therapeutic target for treatment of breast cancer.

Effect of Turkish Propolis on miRNA Expression, Cell Cycle, and Apoptosis in Human Breast Cancer (MCF-7) Cells

Enriched in flavonoid compounds, phenol acids, and terpene derivatives, propolis has been shown to regulate apoptosis signaling pathways and alter the expression of microRNAs (miRNAs). In the present study, it has been aimed to examine the effects of Turkish propolis on miRNA levels of breast cancer (MCF-7) cells, and its relationship with cell proliferation and apoptosis. Cytotoxic activity of ethanolic propolis extract (EEP) was evaluated using MTT assay. Mechanisms involved in the cytotoxic action of Turkish propolis in MCF-7 cells were investigated with regard to apoptosis and cell cycle using flow cytometry and western blot. Mitochondrial membrane potential (MMP) were evaluated by spectrofluorometric method. miRNA levels were detected by qRT-PCR method. EEP exhibited selective toxicity against MCF-7 cells compared to normal fibroblast cells. EEP increased the cell cycle arrest at the G1 phase. EEP elevated the apoptotic cell death through increasing pro-apoptotic protein levels (p21, Bax, p53, p53-Ser46, and p53-Ser15), decreasing MMP and altering the expression levels of specific tumor suppressors (miR-34, miR-15a, and miR-16-5p) and oncogenic (miR-21) miRNAs. These data support that Turkish propolis may be evaluated as a potential natural agent for new anticancer drugs in future.

Determination of Vulpinic Acid Effect on Apoptosis and mRNA Expression Levels in Breast Cancer Cell Lines.

Breast cancer is one of the most common diseases among women worldwide and it is characterized by a high ratio of malignancy and metastasis and low rate of survival of patients. Due to limited treatment options, the discovery of alternative therapeutic agents and clarifying the molecular mechanism of breast cancer development may offer new hope for its treatment. Lichen secondary metabolites may be one of these therapeutic agents. In this study, the effects of Vulpinic Acid (VA) lichen secondary metabolite on the cell viability and apoptosis of breast cancer cells and non-cancerous cell line were investigated. Quantitative polymerase chain reaction was also performed to determine changes in the expression of apoptosis-related genes at a molecular level. The results demonstrated that VA significantly inhibited the cell viability and induced apoptosis of human breast cancer cells. The highest rates of decreased growth were determined using the IC50 value of VA for 48h on MCF-7 breast cancer cell. Interestingly, VA treatment significantly reduced cell viability in all examined breast cancer cell lines compared to their non-cancerous human breast epithelial cell line. This is the first study on the investigation of the effects of VA on the molecular mechanisms associated with the expression of apoptosis-related genes in breast cancer cell lines. Results demonstrated that the gene expression of P53 genes was altered up to fourteen-fold levels in SK-BR-3 cell lines whereas it reached 2.5-fold in the MCF-12A cell line after treatment with VA. These observations support that VA induces apoptosis on the breast cancer cells compared with the non-cancerous human breast epithelial cell line. It is implicated that VA may be a promising novel molecule for the induction of apoptosis on breast cancer cells.

Sophoraflavanone G from Sophora flavescens induces apoptosis in triple-negative breast cancer cells

BackgroundA compound isolated from Sophora flavescens–sophoraflavanone G (SG)–showed anti-tumor and anti-inflammatory properties. We previously demonstrated that SG promoted apoptosis in human leukemia HL-60 cells. In the present study, we investigated the effects of SG on apoptosis in human breast cancer MDA-MB-231 cells, and explored the underlying molecular mechanisms. MethodsMDA-MB-231 cells were treated with various SG concentrations, and cell viability was evaluated by MTT assay. Apoptotic signal proteins were detected by western blotting, and cell apoptosis was assessed using flow cytometry. ResultsOur results demonstrated that SG induced nuclear condensation, DNA fragmentation, reactive oxygen species production, and increased cell apoptosis in MDA-MB-231 cells. SG also suppressed migration and invasion, likely via blockage of the MAPK pathway. In the apoptotic signaling pathway, SG increased cleaved caspase-8, caspase-3, and caspase-9. SG treatment also decreased Bcl-2 and Bcl-xL expression, increased Bax expression, and prompted release of more cytochrome c from mitochondria to the cytoplasm in MDA-MB-231 cells. ConclusionOverall, our findings suggest that SG might increase apoptosis, and decrease migration and invasion, in MDA-MB-231 cells through suppression of a MAPK-related pathway.

Design, synthesis and pharmacological evaluation of N-(5-chloro-2,4-dihydroxybenzoyl)-(R)-N-arylmethyl-1,2,3,4-tetrahydro-3-isoquinolinecarboxamides as potent Hsp90 inhibitors

Using diverse arylmethyl groups to replace the benzyl moiety of the lead Hsp90 inhibitor 1 (N-(5-chloro-2,4-dihydroxybenzoyl)-(R)-N-benzyl-1,2,3,4-tetrahydro-3-iso quinolinecarboxamide), thirty four derivatives (10–43) were developed, and exhibited improved Hsp90 inhibitory and antiproliferative activities. SAR analysis indicated that the southeastern aryl substitutions influenced their antiproliferative activities obviously, with the para-pyridyl group (41) outperforming all other substitution patterns. In this regard, compound 41 was selected for further evaluation. CETSA melt and ITDRFCETSA (isothermal dose-response fingerprint) curves for Hsp90α further proved that 41 interacted with intracellular Hsp90α powerfully. Compared with the lead compound 1, docking and MD refinement of the Hsp90α-41 complex revealed a favorable H-bonding interaction between the side-chain of Tyr139 and the pyridine moiety of 41, which is the first time to be used for resorcinol-based Hsp90 inhibitors. With broad-spectral antitumor activity, compound 41 induced time- and dose-dependent growth inhibition and G0/G1 cell cycle arrest on human breast cancer MDA-MB-453 cell line. In addition, flow cytometry and Western blot analyses confirmed that 41 induced apoptosis of human breast cancer MDA-MB-453 cell line. Via degradation of IKKs and suppression of IKKs activity, compound 41 inhibited TNF-α-induced NF-κB activation. The overall properties warrant compound 41 a promising Hsp90 inhibitor and further biological characterizations. This study provides insights into the chemical evolution of Hsp90 inhibitors, and may facilitate the design of next generation Hsp90 inhibitors for the antitumor drug development.

Patuletin induces apoptosis of human breast cancer SK-BR-3 cell line via inhibiting fatty acid synthase gene expression and activity.

Fatty acid synthase (FASN) is a key enzyme involved in fatty acid biosynthesis and serves an important role in breast cancer development. The aim of the present study was to investigate the effects of patuletin on the gene expression and activity of FASN in the human breast cancer SK-BR-3 cell line, and the apoptotic effects of patuletin to breast cancer cells. Quantitative reverse transcription polymerase chain reaction, western blotting and intracellular FASN activity assays were used to evaluate FASN gene expression, protein expression and activity in patuletin-treated SK-BR-3 cells. MTT assays and flow cytometry were used to measure cell growth and cell apoptosis, respectively, following patuletin treatment. As a result, it was demonstrated that patuletin dose-dependently reduces FASN expression and intracellular activity in human breast cancer cells, and induces apoptosis in FASN over-expressing SK-BR-3 cells. Notably, apoptosis is associated with the reduction of intracellular FASN activity. The present study demonstrates that patuletin may be considered as a novel natural inhibitor of FASN, may induce anti-proliferative and pro-apoptotic effects in certain human breast cancer cells and may be useful for preventing and/or treating human breast cancer.

Fangchinoline inhibits migration and causes apoptosis of human breast cancer MDA-MB-231 cells.

In order to improve outcomes after breast cancer treatment, it is essential to understand the mechanisms of action of potential therapeutic agents. The effect of fangchinoline (FAN) on migration and apoptosis of human breast cancer MDA-MB-231 cells and its underlying mechanisms were investigated. MDA-MB-231 cells were treated with different concentrations of FAN, growth inhibition rates were measured by MTT assay and morphological changes of apoptotic cells were observed by Hoechst staining. The wound-healing assay was used to determine of the effect of FAN on the migration of MDA-MB-231 cells. ELISA was used to detect the expression of MMP-2 and −9 in MDA-MB-231 cells treated with different concentrations of FAN and western blot analysis was used to quantify expression of NF-κβ and Iκβ proteins in the same cells. Our results showed that FAN significantly inhibited the growth of MDA-MB-231 cells in concentration-dependent manner and it induced MDA-MB-231 cell apoptosis. With the high FAN concentrations and long exposure times, the levels of MMP-2 and −9 decreased and the expression of NF-κβ decreased, while the expression of Iκβ protein increased. Based on these results, the antitumor effects of FAN on breast cancer cells can be explained at least partially by inducing apoptosis and inhibiting the migration of MDA-MB-231 cells.

Novel quinuclidinone derivatives induced apoptosis in human breast cancer via targeting p53

Small molecules that can target human cancers have been highly sought to increase the anticancer efficacy, the present work describes the design and synthesis of novel series of five quinuclidinone derivatives (2a-2e). Their anticancer activities were investigated against breast cancer cells MCF-7, MDA-MB-231 breast cancer cells harboring mutant p53 and normal breast counterpart MCF-12a. Derivative 2e reduced proliferation of MCF-7 and MCF-12a while it has no effect on MDA-MB-231. Derivative 2e induced apoptosis in MCF-7 cells which is further confirmed by TUNEL assay and it reduced the percentage of cell in G2/M phase as confirmed by increased expression of cyclin B and reduced expression of cyclin D1. Derivative 2e reduced expression levels of Mdm2, Akt and ERK1/2 by and increased expression level of p53. Moreover, the apoptosis induction by 2e was also inhibited by PFT-α as evidenced by non-significant induction of apoptosis after treatment of MCF-7 cells with both derivative 2e and PFT-α. In addition, docking study reveals that derivative 2e has a binding pattern close to the pattern observed in the structure of the lead fragment 5,6-dimethoxy-2-methylbenzothiazole bound to T-p53C-Y220C. The above findings demonstrate that derivative 2e induces apoptosis in MCF-7 cells via targeting p53 which merits further development.