MCT4 and CD147 colocalize with MMP14 in invadopodia and support matrix degradation and invasion by breast cancer cells.

Expression levels of the lactate-H+ cotransporter MCT4 (also known as SLC16A3) and its chaperone CD147 (also known as basigin) are upregulated in breast cancers, correlating with decreased patient survival. Here, we test the hypothesis that MCT4 and CD147 favor breast cancer invasion through interdependent effects on extracellular matrix (ECM) degradation. MCT4 and CD147 expression and membrane localization were found to be strongly reciprocally interdependent in MDA-MB-231 breast cancer cells. Overexpression of MCT4 and/or CD147 increased, and their knockdown decreased, migration, invasion and the degradation of fluorescently labeled gelatin. Overexpression of both proteins led to increases in gelatin degradation and appearance of the matrix metalloproteinase (MMP)-generated collagen-I cleavage product reC1M, and these increases were greater than those observed upon overexpression of each protein alone, suggesting a concerted role in ECM degradation. MCT4 and CD147 colocalized with invadopodia markers at the plasma membrane. They also colocalized with MMP14 and the lysosomal marker LAMP1, as well as partially with the autophagosome marker LC3, in F-actin-decorated intracellular vesicles. We conclude that MCT4 and CD147 reciprocally regulate each other and interdependently support migration and invasiveness of MDA-MB-231 breast cancer cells. Mechanistically, this involves MCT4-CD147-dependent stimulation of ECM degradation and specifically of MMP-mediated collagen-I degradation. We suggest that the MCT4-CD147 complex is co-delivered to invadopodia with MMP14.

SHARPIN S146 phosphorylation mediates ARP2/3 interaction, cancer cell invasion and metastasis.

SHARPIN is involved in several cellular processes and promotes cancer progression. However, how the choice between different functions of SHARPIN is post-translationally regulated is unclear. Here, we characterized SHARPIN phosphorylation by mass spectrometry and in vitro kinase assay. Focusing on S131 and S146, we demonstrate that they have a role in SHARPIN-ARP2/3 complex interaction, but play no role in integrin inhibition or LUBAC activation. Consistent with its novel role in ARP2/3 regulation, S146 phosphorylation of SHARPIN promoted lamellipodia formation. We also demonstrate that SHARPIN S146 phosphorylation-mediated ARP2/3 interaction is sensitive to inhibition of ERK1/2 or reactivation of protein phosphatase 2A (PP2A). Notably, CRISPR/Cas9-mediated knockout of SHARPIN abrogated three-dimensional (3D) invasion of several cancer cell lines. The 3D invasion of cancer cells was rescued by overexpression of the wild-type SHARPIN, but not by SHARPIN S146A mutant. Finally, we demonstrate that inhibition of phosphorylation at S146 significantly reduces in vivo metastasis in a zebrafish model. Collectively, these results map SHARPIN phosphorylation sites and identify S146 as a novel phosphorylation switch defining ARP2/3 interaction and cancer cell invasion. This article has an associated First Person interview with the first author of the paper.

Restoring microRNA-34a overcomes acquired drug resistance and disease progression in human breast cancer cell lines via suppressing the ABCC1 gene.

PURPOSE: Breast cancer is one of the leading types of cancer diagnosed in women. Despite the improvements in chemotherapeutic cure strategies, drug resistance is still an obstacle leading to disease aggressiveness. The small non-coding RNA molecules, miRNAs, have been implicated recently to be involved as regulators of gene expression through the silencing of mRNA targets that contributed to several cellular processes related to cancer metastasis. Hence, the present study aimed to investigate the beneficial role and mechanism of miRNA-34a-based gene therapy as a novel approach for conquering drug resistance mediated by ATP-binding cassette (ABC) transporters in breast cancer cells, besides exploring the associated invasive behaviors. MATERIAL AND METHODS: Bioinformatics tools were used to predict miRNA ABC transporter targets by tracking the ABC transporter pathway. After the establishment of drug-resistant breast cancer MCF-7 and MDA-MB-231 sublines, cells were transfected with the mimic or inhibitor of miRNA-34a-5p. The quantitative expression of genes involved in drug resistance was performed by QRT-PCR, and the exact ABC transporter target specification interaction was confirmed by dual-luciferase reporter assay. Furthermore, flow cytometric analysis was utilized to determine the ability of miRNA-34a-treated cells against doxorubicin uptake and accumulation in cell cycle phases. The spreading capability was examined by colony formation, migration, and wound healing assays. The apoptotic activity was estimated as well. RESULTS: Our findings firstly discovered the mechanism of miRNA-34a-5p restoration as an anti-drug-resistant molecule that highly significantly attenuates the expression of ABCC1 via the direct targeting of its 3'- untranslated regions in resistant breast cancer cell lines, with a significant increase of doxorubicin influx by MDA-MB-231/Dox-resistant cells. Additionally, the current data validated a significant reduction of metastatic potentials upon miRNA-34a-5p upregulation in both types of breast cancer-resistant cells. CONCLUSION: The ectopic expression of miRNA-34a ameliorates the acquired drug resistance and the migration properties that may eventually lead to improved clinical strategies and outcomes for breast cancer patients. Additionally, miRNA-34a could be monitored as a diagnostic/prognostic biomarker for resistant conditions.

Elevated extracellular inorganic phosphate inhibits ecto-phosphatase activity in breast cancer cells: Regulation by hydrogen peroxide.

For cells to obtain inorganic phosphate, ectoenzymes in the plasma membrane, which contain a catalytic site facing the extracellular environment, hydrolyze phosphorylated molecules. In this study, we show that increased Pi levels in the extracellular environment promote a decrease in ecto-phosphatase activity, which is associated with Pi-induced oxidative stress. High levels of Pi inhibit ecto-phosphatase because Pi generates H2 O2 . Ecto-phosphatase activity is inhibited by H2 O2 , and this inhibition is selective for phospho-tyrosine hydrolysis. Additionally, it is shown that the mechanism of inhibition of ecto-phosphatase activity involves lipid peroxidation. In addition, the inhibition of ecto-phosphatase activity by H2 O2 is irreversible. These findings have new implications for understanding ecto-phosphatase regulation in the tumor microenvironment. H2 O2 stimulated by high Pi inhibits ecto-phosphatase activity to prevent excessive accumulation of extracellular Pi, functioning as a regulatory mechanism of Pi variations in the tumor microenvironment.

Comparative characterisation of an ecto-5'-nucleotidase (CD73) in non-tumoral MCF10-A breast cells and triple-negative MDA-MB-231 breast cancer cells.

Ecto-5'-nucleotidase (CD73) hydrolyses 5'AMP to adenosine and inorganic phosphate. Breast cancer cells (MDA-MB-231) express high CD73 levels, and this enzyme has been found to play a tumour-promoting role in breast cancer. However, no studies have sought to investigate whether CD73 has differential affinity or substrate preferences between noncancerous and cancerous breast cells. In the present study, we aimed to biochemically characterise ecto-5'-nucleotidase in breast cancer cell lines and assess whether its catalytic function and tumour progression are correlated in breast cancer cells. The results showed that compared to nontumoral breast MCF-10A cells, triple-negative breast cancer MDA-MB-231 cells had a higher ecto-5'-nucleotidase expression level and enzymatic activity. Although ecto-5'-nucleotidase activity in the MDA-MB-231 cell line showed no selectivity among monophosphorylated substrates, 5'AMP was preferred by the MCF-10A cell line. Compared to the MCF-10A cell line, the MDA-MB-231 cell line has better hydrolytic ability, lower substrate affinity, and high inhibitory potential after treatment with a specific CD73 inhibitor α,ß­methylene ADP (APCP). Therefore, we demonstrated that a specific inhibitor of the ecto-5-nucleotidase significantly reduced the migratory and invasive capacity of MDA-MB-231 cells, suggesting that ecto-5-nucleotidase activity might play an important role in metastatic progression.

Design, synthesis, and biological evaluation of chalcone acetamide derivatives against triple negative breast cancer.

Chalcones are chemical scaffolds found in natural products, particularly in plants, and are considered for structural diversity in medicinal chemistry for drug development. Herein, we designed and synthesised novel acetamide derivatives of chalcone, characterizing them using 1H NMR, 13C NMR, HRMS, and IR spectroscopic methods. These derivatives were then screened against human cancer cells for cytotoxicity using the SRB assay. Among the tested derivatives, 7g, with a pyrrolidine group, exhibited better cell growth inhibition activity against triple-negative breast cancer (TNBC) cells. Further assays, including SRB, colony formation, and fluorescent dye-based microscopic analysis, confirmed that 7g significantly inhibited MDA-MB-231 cell proliferation. Furthermore, 7g promoted apoptosis by upregulating cellular reactive oxygen species (ROS) levels and disrupting mitochondrial membrane potential (MMP). Elevated expression of pro-apoptotic proteins (Bax and caspase-3) and a higher Bax/Bcl-2 ratio with downregulation of anti-apoptotic (Bcl-2) protein levels were observed in TNBC cells. The above results suggest that 7g can promote cellular death through apoptotic mechanisms in TNBC cells.

Amelioratedin vitroanti-cancer efficacy of methotrexate loaded zinc oxide nanoparticles in breast cancer cell lines MCF-7 & MDA-MB-231 and its acute toxicity study.

Traditional therapies often struggle with specificity and resistance in case of cancer treatments. It is therefore important to investigate new approaches for cancer treatment based on nanotechnology. Zinc oxide nanoparticles (ZnONPs) are known to exhibit anti-cancer properties by inducing oxidative stress, apoptosis, and cell cycle arrest. Methotrexate (MTX) a known anti-folate shows specificity to folate receptors and interrupts healthy functioning of cells. This study proposes the use of previously characterized biocompatible Methotrexate loaded Zinc oxide nanoparticles (MTX-ZnONPs) as a dual action therapeutic strategy against breast cancer cell lines, MCF-7 (MTX-sensitive) and MDA-MB-231 (MTX-resistant). To elucidate the cytotoxicity mechanism of MTX-ZnONPs an in depthIn vitrostudy was carried out.In vitroassays, including cell cycle analysis, apoptosis assay, and western blot analysis to study the protein expression were performed. Results of these assays, further supported the anti-cancer activity of MTX-ZnONPs showing apoptotic and necrotic activity in MCF-7 and MDA-MB-231 cell line respectively.In vivoacute oral toxicity study to identify the LD50in animals revealed no signs of toxicity and mortality up to 550 mg kg-1body weight of animal, significantly higher LD50values than anticipated therapeutic levels and safety of the synthesized nanosystem. The study concludes that MTX-ZnONPs exhibit anti-cancer potential against breast cancer cells offering a promising strategy for overcoming resistance.

Effects of CD44 siRNA on inhibition, survival, and apoptosis of breast cancer cell lines (MDA-MB-231 and 4T1).

BACKGROUND: Breast cancer (BC) is one of the most common cancers in the world. Despite the many advances that have been made in treating patients, many patients are still resistant to treatment. CD44 is one of the surface glycoproteins of BC cells that plays an important role in the proliferation of these cells and inhibition of their apoptosis. Therefore, targeting it can be a treatment way for BC patients. METHODS: In this study, the effect of anti-CD44 siRNA on the proliferation, apoptosis, and migration rate of MDA-MB-231 and 4T1 cells was investigated. The techniques used in this study were MTT assay, RT-PCR, and flow cytometry. RESULTS: The apoptosis and proliferation rates in CD44 siRNA-treated cells were higher and lower, respectively, compared to untreated cells. Also, cell migration was less in treated cells compared to untreated cells. CD44 siRNA also decreased the expression of CXCR4, c-myc, Vimentin, ROCK, and MMP-9. CONCLUSION: Finally, CD44 targeting can be a good treatment option to make BC cells more sensitive to apoptosis.

The ras-related protein RAB22A interacts with hypoxia-inducible factor 1-alpha (HIF-1α) in MDA-MB-231 breast cancer cells in hypoxia.

BACKGROUND: Recent studies suggest that hypoxia-inducible factor 1-alpha (HIF-1α) and the small GTPase protein Ras-related protein Rab-22 A (RAB22A) may be colocalized in the cytoplasm and that as a conequence they may enhance the formation of microvesicles in breast cancer cells under hypoxia. Therefore, we sought to determine whether these two proteins are present in intracellular complexes in breast carcinoma cells. METHODS AND RESULTS: Evaluation using molecular docking indicated that HIF-1α and RAB22A interact with each other. Co-immunoprecipitation of endogenous or ectopically expressed HIF-1α and RAB22A proteins in MDA-MB-231 breast cancer cells or HEK-293T cells demonstrated that endogenous HIF-1α and RAB22A can form an intracellular complex; however, transiently expressed HIF-1α and RAB22A failed to interact. Investigating RAB22A and HIF-1α interactions in various cancer cell lines under hypoxia may shed light on their roles in cancer cell survival and progression through regulation of intracellular trafficking by HIF-1α under hypoxic conditions. CONCLUSIONS: Our study is the first to reveal the potential involvement of HIF-1α in intracellular trafficking through physical interactions with the small GTPase protein RAB22A. We discuss the implications of our work on the role of exosomes and microvesicles in tumor invasiveness.

Induction of breast cancer cell apoptosis by novel thiouracil-fused heterocyclic compounds through boosting of Bax/Bcl-2 ratio and DFT study.

Breast cancer is a common public health disease causing mortality worldwide. Thus, providing novel chemotherapies that tackle breast cancer is of great interest. In this investigation, novel pyrido[2,3-d]pyrimidine derivatives 3,4,(6a-c),(8a,b),9-20 were synthesized and characterized using a variety of spectrum analyses. The geometric and thermal parameters of the novel thiouracil derivatives 3,4,6a,(8a,b),11,12,17,18, 19 were measured using density functional theory (DFT) via DFT/B3LYP/6-31 + G(d,p) basis set. All synthesized compounds were evaluated by MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide) method using MCF-7 and MDA-MB-231 breast cancerous cells, compound 17 had the maximum anticancer activity against both breast cancerous cells, recording the lowest half-maximal inhibitory concentration (IC50) values (56.712 µg/mL for MCF-7 cells and 48.743 µg/mL for MDA-MB-231 cells). The results were confirmed in terms of the intrinsic mechanism of apoptosis, where compound 17 had the highest percentage in the case of both cancer cells and recorded Bax (Bcl-2 associated X)/Bcl-2 (B-cell lymphoma 2) ratio 17.5 and 96.667 for MCF-7 and MDA-MB-231 cells, while compound 19 came after 17 in the ability for induction of apoptosis, where the Bax/Bcl-2 ratio was 15.789 and 44.273 for both cancerous cells, respectively. Also, compound 11 recorded a high Bax/Bcl-2 ratio for both cells. The safety of the synthesized compounds was applied on normal WI-38 cells, showing minimum cytotoxic effect with undetectable IC50. Compounds 17, 11, and 19 recorded a significant increase of p53 upregulated modulator of apoptosis (PUMA) expression levels in the cancerous cells. The DFT method was also used to establish a connection between the experimentally determined values of the present investigated compounds and their predicted quantum chemical parameters. It was concluded that Compounds 17, 11, and 19 had anti-breast cancer potential through the induction of apoptotic Bax/Bcl-2 and PUMA expression levels.

Inhibition of the membrane repair protein annexin-A2 prevents tumor invasion and metastasis.

Cancer cells are exposed to major compressive and shearing forces during invasion and metastasis, leading to extensive plasma membrane damage. To survive this mechanical stress, they need to repair membrane injury efficiently. Targeting the membrane repair machinery is thus potentially a new way to prevent invasion and metastasis. We show here that annexin-A2 (ANXA2) is required for membrane repair in invasive breast and pancreatic cancer cells. Mechanistically, we show by fluorescence and electron microscopy that cells fail to reseal shear-stress damaged membrane when ANXA2 is silenced or the protein is inhibited with neutralizing antibody. Silencing of ANXA2 has no effect on proliferation in vitro, and may even accelerate migration in wound healing assays, but reduces tumor cell dissemination in both mice and zebrafish. We expect that inhibiting membrane repair will be particularly effective in aggressive, poor prognosis tumors because they rely on the membrane repair machinery to survive membrane damage during tumor invasion and metastasis. This could be achieved either with anti-ANXA2 antibodies, which have been shown to inhibit metastasis of breast and pancreatic cancer cells, or with small molecule drugs.

GPR39-mediated ERK1/2 signaling reduces permethrin-induced proliferation of estrogen receptor α-negative cells.

Certain insecticides are known to have estrogenic effects by activating estrogen receptors through genomic transcription. This has led researchers to associate specific insecticide use with an increased breast cancer risk. However, it is unclear if estrogen receptor-dependent pathways are the only way in which these compounds induce carcinogenic effects. The objective of this study was to determine the impact of the pyrethroid insecticide permethrin on the growth of estrogen receptor negative breast cancer cells MDA-MB-231. Using tandem mass spectrometric techniques, the effect of permethrin on cellular protein expression was investigated, and gene ontology and pathway function enrichment analyses were performed on the deregulated proteins. Finally, molecular docking simulations of permethrin with the candidate target protein was performed and the functionality of the protein was confirmed through gene knockdown experiments. Our findings demonstrate that exposure to 10-40 µM permethrin for 48 h enhanced cell proliferation and cell cycle progression in MDA-MB-231. We observed deregulated expression in 83 upregulated proteins and 34 downregulated proteins due to permethrin exposure. These deregulated proteins are primarily linked to transmembrane signaling and chemical carcinogenesis. Molecular docking simulations revealed that the overexpressed transmembrane signaling protein, G protein-coupled receptor 39 (GPR39), has the potential to bind to permethrin. Knockdown of GPR39 partially impeded permethrin-induced cellular proliferation and altered the expression of proliferation marker protein PCNA and cell cycle-associated protein cyclin D1 via the ERK1/2 signaling pathway. These findings offer novel evidence for permethrin as an environmental breast cancer risk factor, displaying its potential to impact breast cancer cell proliferation via an estrogen receptor-independent pathway.

Evaluation of chlorophyll-loaded mesoporous silica nanoparticles for photodynamic therapy on cancer cell lines.

Chlorophyll (Chl) is a promising natural photosensitizer (PS) in photodynamic treatment (PDT). Mesoporous silica nanoparticles (MSNs) were chosen to increase the effectiveness of PDT. This study aimed to evaluate the synergistic efficacy of chlorophyll-loaded mesoporous silica nanoparticles (Chl-MSNs) with photodynamic therapy (PDT) and to investigate their potential toxicity in HepG2, MDA-MB-231, and HSF cell lines. Chl-MSNs were prepared via the physical adsorption method. TEM, DLS, and zeta potential examined morphology, size, and surface characteristics. MSNs and Chl-MSNs were characterized using the same techniques. HPLC was used to assess the encapsulation efficiency. At pH 7.4, an in vitro release experiment of Chl-MSNs was performed. Chl, MSNs, and Chl-MSNs were applied to the three cell lines at different concentrations and subjected to red (650 nm) and blue (450-500 nm) lasers. MSNs and Chl-MSNs' sizes were 90.338 ± 38.49 nm and 123.84 ± 15.67 nm, respectively, as obtained by TEM; the hydrodynamic diameter for MSNs (93.69 ± 20.53 nm) and Chl-MSNs (212.95 ± 19.76 nm); and their zeta potential values are - 16.7 ± 2.19 mV and - 18.84 ± 1.40 mV. The encapsulation efficiency of Chl-MSNs was 70%. Chl-MSNs displayed no toxicity in dark conditions but showed excellent photostability under blue and red light exposure. Furthermore, using Chl over Chl-MSNs has a higher PDT efficiency than the tested cell lines. Chl-MSNs have the potential to be an effective delivery system. PDT proved to be an essential technique for cancer treatment. Blue laser is recommended over red laser with Chl and MSNs for destroying cancer cells.

Synthesis of Indole-Linked Thiadiazoles and their Anticancer Action against Triple-Negative Breast Cancer.

With a lack of targeted therapy and significantly high metastasis, heterogeneity, and relapse rates, Triple-Negative Breast Cancer (TNBC) offers substantial treatment challenges and demands more chemotherapeutic interventions. In the present study, indole-endowed thiadiazole derivatives have been synthesized and screened for antiproliferative potency against the triple-negative breast cancer MDA-MB-231 cell line. Compound 4 h, possessing chlorophenyl moiety, displays the best anticancer potency (IC50: 0.43 µM) in the cell viability assay. The title compounds demonstrate substantial docking competency against the EGFR receptor (PDB ID: 3POZ), validating their in-vitro ant proliferative action. With a high docking score (-9.9 to -8.7 kcal/mol), the indole hybrids display significant binding propensity comparable to the co-crystallized ligand TAK-285 and occupy a similar strategic position in the active domain of the designated receptor. The quantum and electronic properties of the integrated templates are evaluated through DFT, and optimal values of the deduced global reactivity indices, such as energy gap, electronegativity, ionization potential, chemical potential, electrophilicity, etc., suggest their apt biochemical reactivity. The indole hybrids show near-appropriate pharmacokinetic efficacy and bioavailability in the in-silico studies, indicating their candidacy for potential drug usage. Promising in-vitro anticancer action and binding interfaces project indole conjugates as potential leads in addressing the TNBC dilemma.

Psidium guajav-mediated zinc oxide nanoparticles as a multifunctional, microbicidal, antioxidant and antiproliferative agent against destructive pathogens.

Bio-inspired zinc oxide nanoparticles are gaining immense interest due to their safety, low cost, biocompatibility, and broad biological properties. In recent years, much research has been focused on plant-based nanoparticles, mainly for their eco-friendly, facile, and non-toxic character. Hence, the current study emphasized a bottom-up synthesis of zinc oxide nanoparticles (ZnO NPs) from Psidium guajava aqueous leaf extract and evaluation of its biological properties. The structural characteristic features of biosynthesized ZnO NPs were confirmed using various analytical methods, such as UV-Vis spectroscopy, X-ray diffraction (XRD), energy-dispersive X-ray analysis (EDX), Fourier transform infrared spectroscopy (FT-IR), dynamic light scattering (DLS), Scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HR-TEM). The synthesized ZnO NPs exhibited a hydrodynamic shape with an average particle size of 11.6-80.2 nm. A significant antimicrobial efficiency with minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of 40 and 27 µg/ml for Enterococcus faecalis, followed by 30 and 40 µg/ml for Staphylococcus aureus, 20 and 30 µg/ml for Staphylococcus mutans, 30 µg/ml for Candida albicans was observed by ZnO NPs. Additionally, they showed significant breakdown of biofilms of Streptococcus mutans and Candida albicans indicating their future value in drug-resistance research. Furthermore, an excellent dose-dependent activity of antioxidant property was noticed with an IC50 of 9.89 µg/ml. The antiproliferative potential of the ZnO NPs was indicated by the viability of MDA MB 231 cells, which showed a drastic decrease in response to increased concentrations of biosynthesized ZnO NPs. Thus, the present results open up vistas to explore their pharmaceutical potential for the development of targeted anticancer drugs in the future.

Antiproliferative and Pro-Apoptotic Activity and Tubulin Dynamics Modulation of 1H-Benzimidazol-2-yl Hydrazones in Human Breast Cancer Cell Line MDA-MB-231.

(1) Background: The aim of the work is the evaluation of in vitro antiproliferative and pro-apoptotic activity of four benzimidazole derivatives containing colchicine-like and catechol-like moieties with methyl group substitution in the benzimidazole ring against highly invasive breast cancer cell line MDA-MB-231 and their related impairment of tubulin dynamics. (2) Methods: The antiproliferative activity was assessed with the MTT assay. Alterations in tubulin polymerization were evaluated with an in vitro tubulin polymerization assay and a docking analysis. (3) Results: All derivatives showed time-dependent cytotoxicity with IC50 varying from 40 to 60 µM after 48 h and between 13 and 20 µM after 72 h. Immunofluorescent and DAPI staining revealed the pro-apoptotic potential of benzimidazole derivatives and their effect on tubulin dynamics in living cells. Compound 5d prevented tubulin aggregation and blocked mitosis, highlighting the importance of the methyl group and the colchicine-like fragment. (4) Conclusions: The benzimidazole derivatives demonstrated moderate cytotoxicity towards MDA-MB-231 by retarding the initial phase of tubulin polymerization. The derivative 5d containing a colchicine-like moiety and methyl group substitution in the benzimidazole ring showed potential as an antiproliferative agent and microtubule destabilizer by facilitating faster microtubule aggregation and disrupting cellular and nuclear integrity.

3-NAntC: A Potent Crotoxin B-Derived Peptide against the Triple-Negative MDA-MB-231 Breast Cancer Cell Line.

Breast cancer stands as the most prevalent type of tumor and a significant contributor to cancer-related deaths. Among its various subtypes, triple-negative breast cancer (TNBC) presents the worst prognosis due to its aggressive nature and the absence of effective treatments. Crotoxin, a protein found in the venom of Crotalus genus snakes, has demonstrated notable antitumor activity against aggressive solid tumors. However, its application has been hindered by substantial toxicity in humans. In efforts to address this challenge, Crotoxin B-derived peptides were synthesized and evaluated in vitro for their antitumor potential, leading to the discovery of 3-NAntC. Treatment with 3-NAntC at 1 µg/mL for 72 h notably reduced the viability of MDA-MB-231 cells to 49.0 ± 17.5% (p < 0.0001), while exhibiting minimal impact on the viability of HMEC cells (98.2 ± 13.8%) under the same conditions. Notably, 3-NAntC displayed superior antitumoral activity in vitro compared to cisplatin and exhibited a similar effect to doxorubicin. Further investigation revealed that 3-NAntC decreased the proliferation of MDA-MB-231 cells and induced G2/M phase arrest. It primarily prompted optimal cell death by apoptosis, with a lower incidence of the less desirable cell death by necrosis in comparison to doxorubicin. Additionally, 3-NAntC demonstrated low LDH release, and its cytotoxicity remained unaffected by the autophagy inhibitor 3-MA. In an in vivo zebrafish model, 3-NAntC exhibited excellent tolerability, showing no lethal effects and a low rate of malformations at high doses of up to 75 mg/mL. Overall, 3-NAntC emerges as a novel synthetic peptide with promising antitumor effects in vitro against TNBC cells and low toxicity in vivo.

Design, synthesis, molecular docking, and in vitro studies of 2-mercaptoquinazolin-4(3H)-ones as potential anti-breast cancer agents.

Triple-negative breast cancer (TNBC) comprises 10 % to 20 % of breast cancer, however, it is more dangerous than other types of breast cancer, because it lacks druggable targets, such as the estrogen receptors (ER) and the progesterone receptor (PR), and has under expressed receptor tyrosine kinase, ErbB2. Present targeted therapies are not very effective and other choices include invasive procedures like surgery or less invasive ones like radiotherapy and chemotherapy. This study investigated the potential anticancer activity of some novel quinazolinone derivatives that were designed on the structural framework of two approved anticancer drugs, Ispinesib (KSP inhibitor) and Idelalisib (PI3Kδ inhibitor), to find out solutions for TNBC. All the designed derivatives (3a-l) were subjected to extra precision molecular docking and were synthesized and spectrally characterized. In vitro enzyme inhibition assay of compounds (3a, 3b, 3e, 3 g and 3 h) revealed their nanomolar inhibitory potential against the anticancer targets, KSP and PI3Kδ. Using MTT assay, the cytotoxic potential of compounds 3a, 3b and 3e were found highest against MDA-MB-231 cells with an IC50 of 14.51 µM, 16.27 µM, and 9.97 µM, respectively. Remarkably, these compounds were recorded safe against the oral epithelial normal cells with an IC50 values of 293.60 µM, 261.43 µM, and 222 µM, respectively. The anticancer potential of these compounds against MDA-MB-231 cells was revealed to be associated with their apoptotic activity. This was established by examination with the inverted microscope that revealed the appearance of various apoptotic features like cell shrinkage, apoptotic bodies, and membrane blebbing. Using flow cytometry, the Annexin V/PI-stained cancer cells showed an increase in early and late apoptotic cells. In addition, DNA fragmentation was revealed to occur after treatment with the tested compounds by gel electrophoresis. The relative gene expression of pro-apoptotic and anti-apoptotic genes revealed an overexpression of the P53 and BAX genes and a downregulation of the BCL-2 gene by real-time PCR. So, this work proved that compounds 3a, 3b, and 3e could be developed as anticancer candidates, via their P53-dependent apoptotic activity.

Preliminary anticancer evaluation of new Pd(II) complexes bearing NNO donor ligands.

In this study we presented a novel series of NNO tridentate ligands generating imino, amido and oxo donor pocket for Pd(II) coordination. All the compounds were meticulously characterized by elemental analysis and advanced spectroscopic techniques, including FTIR, proton and carbon NMR. The synthesized compounds underwent rigorous evaluation for their potential as anti-cancer agents, utilizing the aggressive breast cancer cell lines MDA-MB (ATCC) and MCF-7 as a crucial model for assessing growth inhibition in cancer cells. Remarkably, the MTT assay unveiled the robust anti-cancer activity for all palladium complexes against MDA-MB-231 and MCF-7 cells. Particularly, complex [Pd(L1)(CH3CN)] exhibited exceptional potency with an IC50 value of 25.50 ± 0.30 µM (MDA-MB-231) and 20.76 ± 0.30 µM (MCF-7), compared to respective 27.00 ± 0.80 µM and 24.10 ± 0.80 µM for cisplatin, underscoring its promising therapeutic potential. Furthermore, to elucidate the mechanistic basis for the anti-cancer effects, molecular docking studies on tyrosine kinases, an integral target in cancer research, were carried out. The outcome of these investigations further substantiated the remarkable anticancer properties inherent to these innovative compounds. This research offers a compelling perspective on the development of potent anti-cancer agents rooted in the synergy between ligands and Pd(II) complexes and presenting a promising avenue for future cancer therapy endeavors.

Loss of transcription factor EB dysregulates the G1/S transition and DNA replication in mammary epithelial cells.

Triple-negative breast cancer (TNBC) poses significant challenges for treatment given the lack of targeted therapies and increased probability of relapse. It is pertinent to identify vulnerabilities in TNBC and develop newer treatments. Our prior research demonstrated that transcription factor EB (TFEB) is necessary for TNBC survival by regulating DNA repair, apoptosis signaling, and the cell cycle. However, specific mechanisms by which TFEB targets DNA repair and cell cycle pathways are unclear, and whether these effects dictate TNBC survival is yet to be determined. Here, we show that TFEB knockdown decreased the expression of genes and proteins involved in DNA replication and cell cycle progression in MDA-MB-231 TNBC cells. DNA replication was decreased in cells lacking TFEB, as measured by EdU incorporation. TFEB silencing in MDA-MB-231 and noncancerous MCF10A cells impaired progression through the S-phase following G1/S synchronization; however, this proliferation defect could not be rescued by co-knockdown of suppressor RB1. Instead, TFEB knockdown reduced origin licensing in G1 and early S-phase MDA-MB-231 cells. TFEB silencing was associated with replication stress in MCF10A but not in TNBC cells. Lastly, we identified that TFEB knockdown renders TNBC cells more sensitive to inhibitors of Aurora Kinase A, a protein facilitating mitosis. Thus, inhibition of TFEB impairs cell cycle progress by decreasing origin licensing, leading to delayed entry into the S-phase, while rendering TNBC cells sensitive to Aurora kinase A inhibitors and decreasing cell viability. In contrast, TFEB silencing in noncancerous cells is associated with replication stress and leads to G1/S arrest.