Physicochemical characterization and potential cancer therapy applications of hydrogel beads loaded with doxorubicin and GaOOH nanoparticles.

A new type of hybrid polymer particles capable of carrying the cytostatic drug doxorubicin and labeled with a gallium compound was prepared. These microparticles consist of a core and a hydrogel shell, which serves as the structural matrix. The shell can be employed to immobilize gallium oxide hydroxide (GaOOH) nanoparticles and the drug, resulting in hybrid beads with sizes of approximately 3.81 ± 0.09 µm. The microparticles exhibit the ability to incorporate a remarkably large amount of doxorubicin, approximately 0.96 mg per 1 mg of the polymeric carrier. Additionally, GaOOH nanoparticles can be deposited within the hydrogel layer at an amount of 0.64 mg per 1 mg of the carrier. These nanoparticles, resembling rice grains with an average size of 593 nm by 155 nm, are located on the surface of the polymer carrier. In vitro studies on breast and colon cancer cell lines revealed a pronounced cytotoxic effect of the hybrid polymer particles loaded with doxorubicin, indicating their potential for cancer therapies. Furthermore, investigations on doping the hybrid particles with the Ga-68 radioisotope demonstrated their potential application in positron emission tomography (PET) imaging. The proposed structures present a promising theranostic platform, where particles could be employed in anticancer therapies while monitoring their accumulation in the body using PET.

The superiority of innovative spiral-interdigital microelectrode pattern in increasing the sensitivity of tracing synchronization via serum starvation in cellular metabolism.

In order to investigate the changes in the properties of the cell culture solution in the effect of cell synchronization via cell starvation (for 12, 24, and 36 h), a new spiral-interdigital pattern of microelectrode as a biosensor has been proposed. Then, to test its superiority, the results of this spiral-interdigital pattern with the results of the commercial pattern have been compared. The cells were selected from breast cancer standard lines (MDA-MB-231). Changes in CV peaks of the secretions were recorded by the spiral-interdigital pattern, in which increasing the interactive surface with homogenous electric paths had been considered by simulation before fabrication. The results of the simulation and experimental procedures showed a meaningful correlation. The occurrence of CV oxidative peaks at about 0.1-0.4 V and reductive peaks at approximately 0 V in the spiral-interdigital biosensor in the starved MDA-MB-231 cell line has been observed. The starvation situation resembles one that does not cause meaningful cell apoptosis or necrosis, and this method is only used to make the cells synchronized. Also, no peak is observed in normal cell growth conditions. In addition, by using the commercial design of the electrodes, no peak is observed in any of the conditions of normal and synchronized growth of the cells. Therefore, it seems that the observed peaks are caused by the agents that are secreted in the cell culture solution in a synchronized situation. Moreover, the design of the new spiral-interdigital electrode can significantly increase the sensitivity of the sensor to receive these peaks due to more space and a uniform electric field.

Benzylidene-isophorone hybrids with strong anticancer activity.

Isophorone is a cyclic ketone that has gained significant attention in the field of organic chemistry due to its versatile reactivity and structural attributes. Derivatives of isophorone offer a broad spectrum of applications ranging from pharmaceuticals to polymer chemistry. With the aim of developing novel hybrid structures based on benzylidene by combining with isophorone scaffold, we report 3 derivatives of the benzylidene-isophorone hybrids and its potent anticancer activity. In order to optimize the anticancer activity of hybrids di-substitution of -Cl group in C2 and C6 position of phenyl ring (compound1), -OCH3 group in C2 and C5 position of phenyl ring (compound2), and -OCH3 group in C2 and C3 position of phenyl ring (compound3) of benzylidene (PhCH=) moiety were made. The structure of Compounds1,2 and 3 were elucidated using spectral and XRD methods. Compounds1,2 and 3 exhibit space group P c a 21, P-1, and P 1 21/n 1 respectively. Compounds1,2 and 3 were tested for the potent anticancer activity on MDA MB-231 cell line. All the three compounds exhibit good anticancer activity on the breast cancer cells. The parent hybrid with ortho, ortho directing -Cl (1) exhibits strong antiproliferation effect (IC50 = 0.028 µM) on MDA-MB 231 cell line. However, hybrid structures with ortho, meta directing -OCH3 (2) group showed moderate effect (IC50 = 0.061 µM) and hybrid with ortho, meta directing -OCH3 (3) substitution showed the least potent anticancer activity (IC50 = 0.074 µM). The benzylidene-isophorone hybrids exhibit anticancer effects in the following order: 1 > 2 > 3.

Network Pharmacology and Experimental Validation to Explore the Potential Mechanism of Nigella sativa for the Treatment of Breast Cancer.

Breast cancer is a prevalent and potentially life-threatening disease that affects women worldwide. Natural products have gained attention as potential anticancer agents due to their fewer side effects, low toxicity, and cost effectiveness compared to traditional chemotherapy drugs. In the current study, the network pharmacology approach was used following a molecular docking study to evaluate the therapeutic potential of N. sativa-derived phytochemicals against breast cancer. Specifically, the study aimed to identify potential anticancer agents targeting key proteins implicated in breast cancer progression. Five proteins (i.e., EGFR, MAPK3, ESR1, MAPK1, and PTGS2) associated with breast cancer were selected as receptor proteins. Fourteen phytochemicals from N. sativa were prioritized based on drug-likeness (DL) and oral bioavailability (OB) parameters (with criteria set at DL > 0.18 and OB > 30%, respectively). Subsequent analysis of gene targets identified 283 overlapping genes primarily related to breast cancer pathogenesis. Ten hub genes were identified through topological analysis based on their significance in the KEGG pathway and GO annotations. Molecular docking revealed strong binding affinities between folic acid, betulinic acid, stigmasterol, and selected receptor proteins. These phytochemicals also demonstrated druggability potential. In vitro experiments in the MDA-MB-231 breast cancer cell line revealed that betulinic acid and stigmasterol significantly reduced cell viability after 24 h of treatment, confirming their anticancer activity. Furthermore, in vivo evaluation using a DMBA-induced rat model showed that betulinic acid and stigmasterol contributed to the significant recovery of cancer markers. This study aimed to explore the mechanisms underlying the anticancer potential of N. sativa phytochemicals against breast cancer, with the ultimate goal of identifying novel therapeutic candidates for future drug development. Overall, these results highlight betulinic acid and stigmasterol as promising candidates to develop novel anticancer agents against breast cancer. The comprehensive approach of this study, which integrates network pharmacology and molecular docking study and its experimental validation, strengthens the evidence supporting the therapeutic benefits of N. sativa-derived phytochemicals in breast cancer treatment, making them promising candidates for the development of novel anticancer agents against breast cancer.

Investigation the apoptotic effect of silver nanoparticles (Ag-NPs) on MDA-MB 231 breast cancer epithelial cells via signaling pathways.

Background: The discovery of novel cancer therapeutic strategies leads to the development of nanotechnology-based methods for cancer treatment. Silver nanoparticles (Ag-NPs) have garnered considerable interest owing to their size, shape, and capacity to modify chemical, optical, and photonic properties. This study aimed to investigate the impact of Ag-NPs on inducing of apoptosis in MDA-MB 231 cells by examining specific signaling pathways. Materials and methods: The cytotoxicity of Ag-NPs was determined using an MTT assay in MDA-MB 231 cells. The apoptotic effects were assessed using the Annexin-V/PI assay. Real-time PCR and western blotting were conducted to analyze the expression of apoptosis-related genes and proteins, respectively. Levels of ERK1/2 and cyclin D1 were measured using ELISA. Cell cycle assay was determined by flow cytometry. Cell migration was evaluated by scratch assay. Results: The results revealed that Ag-NPs triggered apoptosis and cell cycle arrest in MDA-MB 231 cells. The expression level of Bax (pro-apoptotic gene) was increased, while Bcl-2 (anti-apoptotic gene) expression was decreased. Increased apoptosis was correlated with increased levels of p53 and PTEN. Additionally, notable alterations were observed in protein expression related to the Janus kinase/Signal transducers (JAK/STAT) pathway, including p-AKT. Additionally, reduced expression of h-TERT was observed following exposure to Ag-NPs. ELISA results demonstrated a significant reduction in p-ERK/Total ERK and cyclin D1 levels in Ag-NPs-exposed MDA-MB 231 cells. Western blotting analysis also confirmed the reduction of p-ERK/Total ERK and cyclin D1. Decreased level of cyclin D is associated with suppression of cell cycle progression. The migratory ability of MDA-MB-231 cells was reduced upon treatment with Ag-NPs. Conclusions: Our findings revealed that Ag-NPs influenced the proliferation, apoptosis, cell cycle, and migration in MDA-MB 231 cells, possibly by modulating protein expression of the AKT/ERK/Cyclin D1 axis.

Insight into the differential toxicity of PFOA and PFBA based on a 3D-cultured MDA-MB-231 cell model.

Perfluoroalkyl substances (PFASs) are a category of high-concerned emerging contaminants which are suspected to correlate with various human adverse health outcomes including tumors. It is also a question whether short-chain PFASs are qualified alternatives under the regulation of long-chain PFASs. In this study, a three-dimensional (3D) culture system based on Gelatin methacrylate (GelMA) hydrogel matrix was used to investigate the impacts of 120-h perfluorooctanoic acid (PFOA) and perfluorobutanoic acid (PFBA) exposure of MDA-MB-231 cells. The results showed that PFOA exposure promoted the proliferation, migration, and invasion of MDA-MB-231 cells in an environmentally relevant concentration range (0.1 to 10 µM), exhibiting a clear malignant-promoting risk. In contrast, PFBA only showed a trend to induce non-invasive cell migration. Hippo/YAP signaling pathway was identified as the contributor to the differences between the two PFASs. PFOA but PFBA reduced YAP phosphorylation and increased the nuclear content of YAP, which further facilitated abundant key factors of epithelial-mesenchymal transition (EMT) process. Our results provided a new idea for the carcinogenicity of PFOA using a 3D-based paradigm. Although the effects by PFBA were much milder than PFOA in the current test duration, the cell model suitable for longer exposure is still necessary to better assess the safety of alternative short-chain PFASs.

Disclosing a metabolic signature of cisplatin resistance in MDA-MB-231 triple-negative breast cancer cells by NMR metabolomics.

This work compared the metabolic profile of a parental MDA-MB-231 cisplatin-sensitive triple negative breast cancer (TNBC) cell line with that of a derived cisplatin-resistant line, to characterize inherent metabolic adaptations to resistance, as a means for marker and new TNBC therapies discovery. Supported by cytotoxic, microscopic and biochemical characterization of both lines, Nuclear Magnetic Resonance (NMR) metabolomics was employed to characterize cell polar extracts for the two cell lines, as a function of time (0, 24 and 48 h), and identify statistically relevant differences both between sensitive and resistant cells and their time course behavior. Biochemical results revealed a slight increase in activation of the NF-κB pathway and a marked decrease of the ERK signaling pathway in resistant cells. This was accompanied by lower glycolytic and glutaminolytic activities, possibly linked to glutamine being required to increase stemness capacity and, hence, higher survival to cisplatin. The TCA cycle dynamics seemed to be time-dependent, with an apparent activation at 48 h preferentially supported by anaplerotic aromatic amino acids, leucine and lysine. A distinct behavior of leucine, compared to the other branched-chain-amino-acids, suggested the importance of the recognized relationship between leucine and in mTOR-mediated autophagy to increase resistance. Suggested markers of MDA-MB-231 TNBC cisplatin-resistance included higher phosphocreatine/creatine ratios, hypotaurine/taurine-mediated antioxidant protective mechanisms, a generalized marked depletion in nucleotides/nucleosides, and a distinctive pattern of choline compounds. Although the putative hypotheses generated here require biological demonstration, they pave the way to the use of metabolites as markers of cisplatin-resistance in TNBC and as guidance to develop therapies.

Green Lead Nanoparticles Induced Apoptosis and Cytotoxicity in MDA-MB-231 Cells by Inducing Reactive Oxygen Species and Caspase 3/7 Enzymes.

Nanoparticles are widely used in the pharmaceutical, agriculture, and food processing industries. In this study, we have synthesized green lead nanoparticles (gPbNPs) by using an extract of Ziziphus spina-christi leaves and determined their cytotoxic and apoptotic effect on the human breast cancer MDA-MB-231 cell line. gPbNPs were characterized by using X-ray diffraction (XRD), energy dispersive X-ray (EDX) scanning electron microscope (SEM), and transmission electron microscope (TEM). The toxicity of gPbNPs was determined on the MDA-MB-231 cell line using MTT and NRU assays and as a result cell viability was reduced in a concentration-dependent manner. MDA-MB-231 cells were more sensitive at the highest concentration of gPbNPs exposure. In this experiment, we observed the production of intracellular ROS in cells, and induction of caspase 3/7 was higher in cells at 42 µg/ml of gPbNPs. Moreover, the Bax gene was upregulated and the Bcl-2 gene was downregulated and increased caspase 3/7 activity confirmed the apoptotic effect of gPbNPs in cells. Our observation showed that gPbNPs induced cell toxicity, increased generation of intracellular ROS, and gene expression of Bcl-2 and Bax in the MDA-MB-231 cell line. In conclusion, these findings demonstrated that gPbNPs executed toxic effects on the MDA-MB-231 cell line through activating caspase 3/7 activity.

Low-Temperature Vacuum Drying on Broccoli: Enhanced Anti-Inflammatory and Anti-Proliferative Properties Regarding Other Drying Methods.

Low-temperature vacuum drying (LTVD) has shown great potential for drying vegetables. It could avoid excessive degradations of active compounds with potential therapeutic agents. In this study, the effect on several relevant bioactive compounds, anti-inflammatory activity, and anti-proliferative activity of broccoli (Brassica oleracea var. italica) were evaluated. Effects of other drying methods, including vacuum drying (VD), convective drying (CD), infrared drying (IRD), and freeze drying (FD), were also comparatively evaluated. The results of all dried samples showed high polyunsaturated fatty acid contents (of up to 71.3%) and essential amino acid contents (of up to 8.63%). The LTVD method stands out above the other drying methods, since it obtained the highest content of total phenols, chlorogenic acid, and ferulic acid. Both the LTVD and CD samples demonstrated high anti-inflammatory and anti-proliferative activities. These CD and LTVD samples were also the most active against the breast carcinoma MDA-MB-23 cell line. Due to the good retention of bioactive compounds via LTVD, the obtained dried broccoli here can be used in a near time as an ingredient for the development of novel natural products with anti-inflammatory and anti-proliferative effects.

The Role of Akt/Rab5A Signalling in Regulating Cell Migration of MDA-MB-231 Breast Cancer Cell Line.

Rab5A and Akt pathways are reported to be responsible for the invasiveness of cancer cells, indicated by the fact that Rab5A activates the downstream Phosphoinositide-3-kinases (PI3K)/Akt signalling pathway, which results in promoting cancer metastasis. However, little attention has been given to the emerging role of Rab5A and Akt signalling pathways in regulating the direction of MDA-MB-231 cell migration. MDA-MB-231 breast cancer cell line was used as a model in this study because it is highly metastatic and motile. Time-lapse microscopy was used to examine the effect of Akt and Rab5A inhibitors on cell migration, proliferation and wound healing. Later, the cells were transfected with GFP-Akt-PH or GFP-Rab5A (used as a biosensor to detect Akt and Rab5A). Therefore, confocal time-lapse images were used to visualize Akt and Rab5A at the front and rear edges of the cells. The recorded data demonstrated that Akt and Rab5A inhibition reduced cell migration, proliferation and wound healing. The results of the current study also demonstrated that Akt localizes at the trailing edge while Rab5A localize more at the leading edge than the trailing edge of cells. This study suggests that Akt and Rab5A inhibition might regulate the direction of breast cancer migration.

A Novel Breast Cancer Xenograft Model Using the Ostrich Chorioallantoic Membrane-A Proof of Concept.

The avian chorioallantoic membrane (CAM) assay has attracted scientific attention in cancer research as an alternative or complementary method for in vivo animal models. Here, we present a xenograft model based on the ostrich (struthio camelus) CAM assay for the first time. The engraftment of 2 × 106 breast cancer carcinoma MDA-MB-231 cells successfully lead to tumor formation. Tumor growth monitoring was evaluated in eight fertilized eggs after xenotransplantation. Cancer cells were injected directly onto the CAM surface, close to a well-vascularized area. Histological analysis confirmed the epithelial origin of tumors. The CAM of ostrich embryos provides a large experimental surface for the xenograft, while the comparably long developmental period allows for a long experimental window for tumor growth and treatment. These advantages could make the ostrich CAM assay an attractive alternative to the well-established chick embryo model. Additionally, the large size of ostrich embryos compared to mice and rats could help overcome the limitations of small animal models. The suggested ostrich model is promising for future applications, for example, in radiopharmaceutical research, the size of the embryonal organs may compensate for the loss in image resolution caused by physical limitations in small animal positron emission tomography (PET) imaging.

CRISPR/Cas9 mediated knocking out of OPN gene enhances radiosensitivity in MDA-MB-231 breast cancer cell line.

PURPOSE: Although chemotherapy and radiotherapy in conjunction with surgery have been known as the standard methods for patients with breast cancer, they frequently face resistance due to the failure of cells to death. Accordingly, improving the results requires discovering novel therapeutic approaches based on the changes in the molecular biology of cancer cells. Osteopontin (OPN) is a secreted protein that previous studies have shown to be associated with progression, poor prognosis, and metastasis in breast cancer. The current study examined the synergistic effects of radiotherapy and knocking out of OPN gene, utilizing CRISPR/Cas9 technique in MDA-MB-231 breast cancer cells. METHODS: We used to knock out the OPN gene by the two different gRNAs. The cells irradiated 24 h after transfection. The mRNA expression, tumor cell proliferation, cell cycle distribution, growth, and apoptosis were measured. Moreover, activation of Chk1 and AKT were measured via western blot. RESULTS: We demonstrated the OPN knocking out along with radiation led to the promotion of apoptosis, suppression of downstream genes, reduction of cell viability, and inhibition of cell-cycle progression. The western blot analysis has indicated that the knocking out of the OPN gene along with radiotherapy changes DNA damage responses substantially. CONCLUSIONS: The OPN gene knocking out with radiotherapy might be an efficient approach to overcome the radioresistance in breast cancer.

Chondroitin polymerizing factor predicts a poor prognosis and promotes breast cancer progression via the upstream TGF-ß1/SMAD3 and JNK axis activation.

Aberrant composition of glycans in the tumor microenvironment (TME) contributes to tumor progression and metastasis. Chondroitin polymerizing factor (CHPF) is a glycosyltransferase that catalyzes the biosynthesis of chondroitin sulfate (CS). It is also correlated to transforming growth factor-ß1 (TGF-ß1) expression, a crucial mediator in the interaction of cancer cells with TME. In this study, we investigated the association of CHPF expression with the clinicopathological features of breast cancer (BRCA), as well the oncogenic effect and the underling mechanisms of CHPF upon BRCA cells. We found that CHPF expression is significantly increased in human BRCA tissues, and it is positively associated with TGF-ß expression (r = 0.7125). The high-expression of CHPF predicts a poor prognosis and is positively correlated with tumor mass, lymph node metastasis, clinical staging and HER-2 negative-expression. The mechanistic study revealed that it promotes BRCA cell proliferation, migration and invasion through TGF-ß1-induced SMAD3 and JNK activation in vitro, JNK (SP600125) or SMAD3 (SIS3) inhibitor can remove the promotion of CHPF upon cell proliferation, migration and invasion in MDA-MB-231 cells, which is derived from triple-negative breast cancer (TNBC). Collectively, our finding suggested CHPF may function as an oncogene and is highly expressed in human BRCA tissues. Pharmacological blockade of the upstream of JNK or SMAD3 signaling may provide a novel therapeutic target for refractory TNBC patients with CHPF abnormal high-expression.

Photodynamic therapy with zinc phthalocyanine enhances the anti-cancer effect of tamoxifen in breast cancer cell line: Promising combination treatment against triple-negative breast cancer?

Photodynamic therapy (PDT) is a light-based anti-neoplastic therapeutic approach. Growing evidence indicates that combining conventional anti-cancer therapies with PDT can be a promising approach to treat malignancies. Herein, we aimed to investigate anti-cancer effects of the combination treatment of zinc phthalocyanine (ZnPc)-PDT with tamoxifen (TA) on MDA-MB-231 cells (as a triple-negative breast cancer (TNBC) cell line). For this purpose, we investigated the cytotoxicity of TA and ZnPc-PDT on MDA-MB-231 cells performing the MTT assay. The effect of TA and ZnPc-PDT on the apoptosis of MDA-MB-231 cells was studied using Annexin V/PI and DAPI staining. The wound-healing assay, and colony formation assay were performed to study the effect of TA and ZnPc-PDT on the migration, and clonogenicity of MDA-MB-231 cells, respectively. The qRT-PCR was done to study the gene expression of caspase-8, caspase-9, caspase-3, ZEB1, ROCK1, SNAIL1, CD133, CD44, SOX2, and ABCG2 (ATP-binding cassette sub-family G member 2). Based on our results, monotherapies with TA and ZnPc-PDT can remarkably increase cell cytotoxicity effects, stimulate apoptosis via downregulating Bcl-2 and upregulating caspase-3 and caspase-9, inhibit migration via downregulating SNAIL1 and ZEB1, and suppress clonogenicity via downregulating SOX2 and CD44 in MDA-MB-231 cells. Besides, these monotherapies can downregulate the expression of ABCG2 in MDA-MB-231 cells. Nevertheless, the combination treatment can potentiate the above-mentioned anti-cancer effects compared to monotherapy with TA. Of interest, the combined treatment of TA with ZnPc-PDT can synergically increase cell cytotoxicity effects on MDA-MB-231 cells. In fact, synergistic effects were estimated by calculation of Combination Index (CI); that synergistic outcomes were observed in all groups. Also, this combination treatment can significantly upregulate the caspase-8 gene expression and downregulate ROCK1 and CD133 gene expression in MDA-MB-231 cells. Overall, our results show that ZnPc-PDT can more sensitize the MDA-MB-231 cells to TA treatment. Based on our knowledge and experiment, the synergistic effects of ZnPc-PDT and TA deserve further evaluation in cancer research.

Capsanthin-Loaded Micelles: Preparation, Characterization and in vitro Evaluation of Cytotoxicity Using MDA-MB-231 Breast Cancer Cell Line.

Research background: Breast cancer is one of the most common cancers and remains a major cause of morbidity and mortality among women worldwide. In developed countries, breast cancer as a multifactorial disease is a major health concern, and its incidence is constantly rising in low and middle-income countries. Numerous studies have demonstrated that phytochemicals such as carotenoids inhibit breast cancer growth and induce apoptosis. We recently enhanced the solubility of capsanthin in water by encapsulating it in diosgenin polyethylene glycol succinate, a novel non-ionic surfactant. Thus, this study aims to evaluate the cytotoxicity of water-soluble capsanthin-loaded micelles in MDA-MB-231 cells in vitro through tetrazolium dye MTT assay. Experimental approach: In the current study, capsanthin, a hydrophobic carotenoid, is extracted from sweet red pepper (Capsicum annuum). Capsanthin-loaded diosgenin polyethylene glycol succinate 1000 (cap-DPGS-1000) micelles were prepared from capsanthin extract (cap) and diosgenin polyethylene glycol succinate 1000 (DPGS-1000) using the solid dispersion method. The capsanthin extract and cap-DPGS-1000 micelles were characterized by UV-visible spectroscopy, high-performance liquid chromatography (HPLC), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), particle size distribution, polydispersity, and scanning electron microscopy (SEM). The effects of capsanthin extract and cap-DPGS-1000 micelles on a human triple-negative breast cancer cell line (MDA-MB-231) were tested to check the cell viability, proliferation and cytotoxicity of the micelles. Results and conclusions: The solubility of encapsulated cap-DPGS-1000 micelles in water is greatly enhanced and leads to an increased scope for localized drug delivery, a better delivery option for treating residual cancerous tumours. The encapsulated capsanthin showed a sustained release in simulated intestinal fluid (pH=6.8). Our research proposes a sustained drug delivery system that ensures effective and controlled release to the affected site. The characterization data revealed no change in the structure and functional groups in the encapsulated capsanthin. The IC50 value of the cap-DPGS-1000 micelles against MDA-MB-231 breast cancer cells was (3.10±1.09) µg/mL, which is much lower than of capsanthin extract ((81.1±1.5) µg/mL). Capsanthin extract and capsanthin-loaded micelles are promising drug candidates to induce apoptosis and increase reactive oxygen species (ROS) in cancer cells. Novelty and scientific contribution: The result shows the cytotoxic effect of capsanthin and capsanthin-loaded micelles on MDA-MB-231 cell line for the first time. Capsanthin from sweet red pepper (Capsicum annuum) showed remarkable cytotoxic effect on the triple-negative MDA-MB-231 cell line.

Kinetic Changes of Ptdins (3,4,5) P3 within Fast and Slow Turnover Rates of Focal Adhesion.

Background: The assembly and disassembly of the focal adhesions (FA) components occurs throughout life cycle of adhesion, with conservation of balance between removal and recruitment rate during temporal stages. Previous studies have demonstrated that phosphotidyilinositols play a role in regulating FA turnover. However, a little attention has been given to quantify the dynamics changes of Phosphatidylinositol 3,4,5-trisphosphate (PtdIns (3,4,5) P3) within and during fast and slow turnover rates of FA. Methods: In this study, we developed a protein purification MDA-MB-231 breast cancer cell line was used as a model in this study due to high metastatic and motile. These cells were co-transfected with GFP- paxillin/vinculin, as FA marker, and the GFP/mCherry-Btk-PH, as a biosensor to visualize PtdIns (3,4,5) P3. Confocal time-lapse images were used to monitor changes or differences in the local generation of PtdIns (3,4,5) P3 within and during assembly and disassembly of FA. Following transfection, immunostaining was used to examine the spatial co-localization between FA and PtdIns (3,4,5) P3. Results: Our data demonstrated that PtdIns (3,4,5) P3 co-localized with FAs and increase during assembly and decline during disassembly of FA which exhibits slow turnover rates and was in a constant level during assembly and disassembly of FA that displays fast turnover rates. Discussion: Our result suggested that the dynamic changes of PtdIns (3,4,5) P3, it may depend on components undergo turnover, such that early, nascent FA displays fast turnover rates and mature FA exhibits slow turnover rates. Thus, the local enrichment of PtdIns (3,4,5) P3 enhances FA assembly and disassembly activation.

Characterization of Mitochondrial Proteome and Function in Luminal A and Basal-like Breast Cancer Subtypes Reveals Alteration in Mitochondrial Dynamics and Bioenergetics Relevant to Their Diagnosis.

Breast cancer (BC) is the most prevalent cancer and the one with the highest mortality among women worldwide. Although the molecular classification of BC has been a helpful tool for diagnosing and predicting the treatment of BC, developments are still being made to improve the diagnosis and find new therapeutic targets. Mitochondrial dysfunction is a crucial feature of cancer, which can be associated with cancer aggressiveness. Although the importance of mitochondrial dynamics in cancer is well recognized, its involvement in the mitochondrial function and bioenergetics context in BC molecular subtypes has been scantly explored. In this study, we combined mitochondrial function and bioenergetics experiments in MCF7 and MDA-MB-231 cell lines with statistical and bioinformatics analyses of the mitochondrial proteome of luminal A and basal-like tumors. We demonstrate that basal-like tumors exhibit a vicious cycle between mitochondrial fusion and fission; impaired but not completely inactive mitochondrial function; and the Warburg effect, associated with decreased oxidative phosphorylation (OXPHOS) complexes I and III. Together with the results obtained in the cell lines and the mitochondrial proteome analysis, two mitochondrial signatures were proposed: one signature reflecting alterations in mitochondrial functions and a second signature exclusively of OXPHOS, which allow us to distinguish between luminal A and basal-like tumors.

Active nNOS Is Required for Grp94-Induced Antioxidant Cytoprotection: A Lesson from Myogenic to Cancer Cells.

The endoplasmic reticulum (ER) chaperone Grp94/gp96 appears to be involved in cytoprotection without being required for cell survival. This study compared the effects of Grp94 protein levels on Ca2+ homeostasis, antioxidant cytoprotection and protein-protein interactions between two widely studied cell lines, the myogenic C2C12 and the epithelial HeLa, and two breast cancer cell lines, MDA-MB-231 and HS578T. In myogenic cells, but not in HeLa, Grp94 overexpression exerted cytoprotection by reducing ER Ca2+ storage, due to an inhibitory effect on SERCA2. In C2C12 cells, but not in HeLa, Grp94 co-immunoprecipitated with non-client proteins, such as nNOS, SERCA2 and PMCA, which co-fractionated by sucrose gradient centrifugation in a distinct, medium density, ER vesicular compartment. Active nNOS was also required for Grp94-induced cytoprotection, since its inhibition by L-NNA disrupted the co-immunoprecipitation and co-fractionation of Grp94 with nNOS and SERCA2, and increased apoptosis. Comparably, only the breast cancer cell line MDA-MB-231, which showed Grp94 co-immunoprecipitation with nNOS, SERCA2 and PMCA, increased oxidant-induced apoptosis after nNOS inhibition or Grp94 silencing. These results identify the Grp94-driven multiprotein complex, including active nNOS as mechanistically involved in antioxidant cytoprotection by means of nNOS activity and improved Ca2+ homeostasis.

Structure elucidation, in vitro binding studies and ROS-dependent anti-cancer activity of Cu(II) and Zn(II) phthaloylglycinate(phen) complexes against MDA-MB-231 cells.

New mononuclear Cu(II) and Zn(II)-based complexes 1 [Cu(L)2(diimine)HOCH3] and 2 [Zn(L)2(diimine)] have been synthesized as anti-cancer chemotherapeutics targeted to tRNA. The structure elucidation of complexes 1 and 2 was carried out by spectroscopic and single X-ray diffraction studies. In vitro interaction studies of complexes 1 and 2 with ct-DNA/tRNA were performed by employing various biophysical techniques to evaluate and predict their interaction behavior and preferential selectivity at biomolecular therapeutic targets. The corroborative results of the interaction studies demonstrated that complexes 1 and 2 exhibited avid binding propensity via intercalative mode of binding toward ct-DNA/tRNA. Electrophoretic assay revealed that the complexes 1 and 2 were able to promote single- and double-strand cleavage of the plasmid DNA at low micromolar concentrations under physiological conditions in the absence of an additional oxidizing or reducing agent. RNA hydrolysis studies revealed that the complexes 1 and 2 could promote tRNA cleavage in a concentration and time-dependent manner. The cytotoxic potential of complexes 1 and 2 was evaluated against the MDA-MB-231 cell line, which showed that the complexes were able to inhibit the cell growth in a dose-dependent manner. The intracellular ROS production and mitochondrial superoxide anion assay revealed that the complexes 1 and 2 induce a dose-dependent activity, suggesting the involvement of ROS-mediated mitochondrial apoptotic pathway leading to cell death.

Pyoluteorin induces cell cycle arrest and apoptosis in human triple-negative breast cancer cells MDA-MB-231.

OBJECTIVES: To screen the cytotoxic activity of six secondary metabolites isolated from soil fungus Aspergillus niger. Importantly, to investigate the mechanism that pyoluteorin induced human triple-negative breast cancer MDA-MB-231 cells apoptosis in vitro. METHODS: The cell viability assay was tested with CTG assay. Cell cycle, apoptosis and intracellular reactive oxygen species (ROS) production assay were tested with flow cytometry. Additionally, intracellular ROS production assay and mitochondrial membrane potential assay were determined with laser scanning confocal microscopy. The expression of apoptosis-related proteins was determined with Western blot. KEY FINDINGS: Pyoluteorin displayed significantly selective cytotoxicity against human triple-negative breast cancer MDA-MB-231 cells (IC50  = 0.97 µm) with low toxicity against human breast epithelial cell MCF-10A. It was found that pyoluteorin could arrest MDA-MB-231 cells cycle at G2 /M phase and induce cell apoptosis. Further experiments demonstrated that the apoptosis-inducing effect of pyoluteorin was related to reduction of mitochondrial membrane potential, accumulation of ROS and change of apoptosis-related protein expressions. CONCLUSION: Our studies revealed that pyoluteorin had potent proliferation inhibition against MDA-MB-231 cells through arresting cell cycle at G2 /M phase and inducing caspase-3-dependent apoptosis by mitochondrial pathway, implying that pyoluteorin may be a potential lead compound for drug discovery of human triple-negative breast cancer.