Anti-Cancer Potential of Linear ß-(1→6)-D-Glucan from Agaricus bisporus on Estrogen Receptor-Positive (ER+) Breast Cancer Cells.

Mushroom ß-D-glucans can be isolated from several species, including the widely consumed Agaricus bisporus. Besides immunomodulatory responses, some ß-D-glucans may exhibit direct antitumoral effects. It was previously observed that a ß-(1→6)-D-glucan (BDG16) has indirect cytotoxicity on triple-negative breast cancer cells. In this study, the cytotoxicity of this same glucan was observed on estrogen receptor-positive (ER+) breast cancer cells (MCF-7). Cell viability was determined by multiple methods to assess metabolic activity, lysosomal membrane integrity, and adhesion capacity. Assays to evaluate cell respiration, cell cycle, apoptosis, necroptosis, and oxidative stress were performed to determine the action of BDG16 on MCF-7 cells. A gradual and significant cell viability reduction was observed when the cells were treated with BDG16 (10-1000 µg/mL). This result could be associated with the inhibition of the basal state respiration after incubation with the ß-D-glucan. The cells showed a significant arrest in G1 phase population at 1000 µg/mL, with no induction of apoptosis. However, an increase in necrosis and necroptosis at the same concentration was observed. No difference in oxidative stress-related molecules was observed. Altogether, our findings demonstrate that BDG16 directly induces toxicity in MCF-7 cells, primarily by impairing mitochondrial respiration and promoting necroptosis. The specific mechanisms that mediate this action are being investigated.

Ectonucleotidase activity driven by acid ectophosphatase in luminal A MCF-7 breast cancer cells.

Ectophosphatases catalyse the hydrolysis of phosphorylated molecules, such as phospho-amino acids, in the extracellular environment. Nevertheless, the hydrolysis of nucleotides in the extracellular environment is typically catalysed by ectonucleotidases. Studies have shown that acid ectophosphatase, or transmembrane-prostatic acid phosphatase (TM-PAP), a membrane-bound splice variant of prostatic acid phosphatase, has ecto-5'-nucleotidase activity. Furthermore, it was demonstrated that ectophosphatase cannot hydrolyse ATP, ADP, or AMP in triple-negative breast cancer cells. In contrast to previous findings in MDA-MB-231 cells, the ectophosphatase studied in the present work displayed a remarkable capacity to hydrolyse AMP in luminal A breast cancer cells (MCF-7). We showed that AMP dose-dependently inhibited p-nitrophenylphosphate (p-NPP) hydrolysis. The p-NPP and AMP hydrolysis showed similar biochemical behaviours, such as increased hydrolysis under acidic conditions and comparable inhibition by NiCl2, ammonium molybdate, and sodium orthovanadate. In addition, this ectophosphatase with ectonucleotidase activity was essential for the release of adenosine and inorganic phosphate from phosphorylated molecules available in the extracellular microenvironment. This is the first study to show that prostatic acid phosphatase on the membrane surface of breast cancer cells (MCF-7) is correlated with cell adhesion and migration.

Selective Antineoplastic Potential of Fractionated Caribbean Native Ganoderma Species Extracts on Triple-Negative Breast Cancer Cells.

Triple-negative breast cancer (TNBC) is an aggressive subtype characterized by the absence of estrogen receptor, progesterone receptor, and human epidermal growth factor receptor type 2 expression. It is known for its high malignancy, invasiveness, and propensity for metastasis, resulting in a poor prognosis due to the absence of beneficial therapeutic targets. Natural products derived from mushrooms have gained significant attention in neoplastic therapy due to their potential medicinal properties. The therapeutic potential of Ganoderma lucidum in breast cancer has been highlighted by our group, suggesting its use as an adjuvant treatment. The present study aims to assess the potential antineoplastic capacity of two Caribbean native Ganoderma species found in Puerto Rico, Ganoderma multiplicatum (G. multiplicatum) and Ganoderma martinicense (G. martinicense). Antiproliferative studies were conducted via cell viability assays after cultivation, harvesting, and fractionation of both species. The obtained results indicate that most of the fractions show some cytotoxicity against all cell lines, but 33% of the fractions (F1, F2, F7, F12) display selectivity towards cancer cell models. We demonstrate for the first time that native Ganoderma species can generate metabolites with anti-TNBC properties. Future avenues will focus on structure elucidation of the most active fractions of these Ganoderma extracts.

A novel role of IGFBP5 in the migration, invasion and spheroids formation induced by IGF-I and insulin in MCF-7 breast cancer cells.

PURPOSE: The insulin-like growth factor (IGF) system includes IGF-I, IGF-II insulin and their membrane receptors. IGF system also includes a family of proteins namely insulin-like growth factor-binding proteins (IGFBPs) composed for six major members (IGFBP-1 to IGFBP6), which capture, transport and prolonging half-life of IGFs. However, it has been described that IGFBPs can also have other functions. METHODS: IGFBP5 expression was inhibited by shRNAs, migration was analyzed by scratch-wound assays, invasion assays were performed by the Boyden chamber method, spheroids formation assays were performed on ultra-low attachment surfaces, expression and phosphorylation of proteins were analyzed by Western blot. RESULTS: IGFBP5 is a repressor of IGF-IR expression, but it is not a repressor of IR in MCF-7 breast cancer cells. In addition, IGFBP5 is a suppressor of migration and MMP-9 secretion induced by IGF-I and insulin, but it does not regulate invasion in MCF-7 cells. IGFBP5 also is a repressor of MCF-7 spheroids formation. However treatment with 340 nM rescues the inhibitory effect of IGFBP in the MCF-7 spheroids formation. CONCLUSION: IGFBP5 regulates IGF-IR expression, migration and MMP-9 secretion induced by IGF-I and/or insulin, and the spheroids formation in MCF-7 breast cancer cells.

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.

Exploring CDKN1A Upregulation Mechanisms: Insights into Cell Cycle Arrest Induced by NC2603 Curcumin Analog in MCF-7 Breast Cancer Cells.

Breast cancer stands out as one of the most prevalent malignancies worldwide, necessitating a nuanced understanding of its molecular underpinnings for effective treatment. Hormone receptors in breast cancer cells substantially influence treatment strategies, dictating therapeutic approaches in clinical settings, serving as a guide for drug development, and aiming to enhance treatment specificity and efficacy. Natural compounds, such as curcumin, offer a diverse array of chemical structures with promising therapeutic potential. Despite curcumin's benefits, challenges like poor solubility and rapid metabolism have spurred the exploration of analogs. Here, we evaluated the efficacy of the curcumin analog NC2603 to induce cell cycle arrest in MCF-7 breast cancer cells and explored its molecular mechanisms. Our findings reveal potent inhibition of cell viability (IC50 = 5.6 µM) and greater specificity than doxorubicin toward MCF-7 vs. non-cancer HaCaT cells. Transcriptome analysis identified 12,055 modulated genes, most notably upregulation of GADD45A and downregulation of ESR1, implicating CDKN1A-mediated regulation of proliferation and cell cycle genes. We hypothesize that the curcumin analog by inducing GADD45A expression and repressing ESR1, triggers the expression of CDKN1A, which in turn downregulates the expression of many important genes of proliferation and the cell cycle. These insights advance our understanding of curcumin analogs' therapeutic potential, highlighting not just their role in treatment, but also the molecular pathways involved in their activity toward breast cancer cells.

Transcriptomic Changes in Cisplatin-Resistant MCF-7 Cells.

Breast cancer is a leading cause of cancer-related deaths among women. Cisplatin is used for treatment, but the development of resistance in cancer cells is a significant concern. This study aimed to investigate changes in the transcriptomes of cisplatin-resistant MCF7 cells. We conducted RNA sequencing of cisplatin-resistant MCF7 cells, followed by differential expression analysis and bioinformatic investigations to identify changes in gene expression and modified signal transduction pathways. We examined the size and quantity of extracellular vesicles. A total of 724 genes exhibited differential expression, predominantly consisting of protein-coding RNAs. Notably, two long non-coding RNAs (lncRNAs), NEAT1 and MALAT, were found to be dysregulated. Bioinformatic analysis unveiled dysregulation in processes related to DNA synthesis and repair, cell cycle regulation, immune response, and cellular communication. Additionally, modifications were observed in events associated with extracellular vesicles. Conditioned media from resistant cells conferred resistance to wild-type cells in vitro. Furthermore, there was an increase in the number of vesicles in cisplatin-resistant cells. Cisplatin-resistant MCF7 cells displayed differential RNA expression, including the dysregulation of NEAT1 and MALAT long non-coding RNAs. Key processes related to DNA and extracellular vesicles were found to be altered. The increased number of extracellular vesicles in resistant cells may contribute to acquired resistance in wild-type cells.

Phytochemical Screening and in vitro Anticancer Activity of Some Medicinal Plants Grown in the Kingdom of Saudi Arabia / Cribado Fitoquímico y Actividad Anticancerígena in vitro de Algunas Plantas Medicinales Cultivadas en el Reino de Arabia Saudita

SUMMARY: This study evaluated the phytochemical screening, antioxidant capacity, and in vitro anticancer activities of four plants namely, Gypsophila capillaris, Anabasis lachnantha, Haloxylon salicornicum, and Horwoodia dicksoniae which belong to four different families: Caryophyllaceae, Amaranthaceae, Chenopodiaceae, Brassicaceae, respectively. The total phenolics, anthocyanins, saponins, total antioxidant capacity (TAC), and DPPH assays were determined by spectrophotometer. In vitro anticancer activity was assessed using two human cancer cell lines; hepatocellular carcinoma (HepG-2) and breast adenocarcinoma (MCF-7) to estimate the inhibition concentration 50 % (IC50). The results showed that H. dicksoniae has the highest concentrations of phenolics and saponins, while H. salicornicum has the highest DPPH. The highest concentration of TAC was found in G. capillaries. Among the tested extracts, G. capillaries and H. salicornicum have the potential activity against MCF-7 and HepG-2 cell lines in vitro. The content of polyphenols in G. capillaries was profiled by high-performance liquid chromatography (HPLC). The highest concentration among the phenolic compounds was chlorogenic (60.8 µg/ml) while the highest concentration among the flavonoid compounds was hesperidin (1444.92 µg/ml). In summary, G. capillaries and H. salicornicum extracts have potent anticancer activity against HepG-2 and MCF-7 cell lines.

Este estudio evaluó la detección fitoquímica, la capacidad antioxidante y las actividades anticancerígenas in vitro de cuatro plantas, Gypsophila capillaris, Anabasis lachnantha, Haloxylon salicornicum y Horwoodia dicksoniae, que pertenecen a cuatro familias diferentes: Caryophyllaceae, Amaranthaceae, Chenopodiaceae y Brassicaceae, respectivamente. Los ensayos de fenólicos totales, antocianinas, saponinas, capacidad antioxidante total (TAC) y DPPH se determinaron mediante espectrofotómetro. La actividad anticancerígena in vitro se evaluó utilizando dos líneas celulares de cáncer humano; carcinoma hepatocelular (HepG-2) y adenocarcinoma de mama (MCF- 7) para estimar la concentración de inhibición del 50 % (IC50). Los resultados indicaron que H. dicksoniae tiene las concentraciones más altas de fenólicos y saponinas, mientras que H. salicornicum tiene el DPPH más alto. La mayor concentración de TAC se encontró en G. capillaries. Entre los extractos probados, G. capillaries y H. salicornicum tienen actividad potencial contra líneas celulares MCF-7 y HepG-2 in vitro. El contenido de polifenoles en G. capillaries se perfiló mediante cromatografía líquida de alta resolución (HPLC). La concentración más alta entre los compuestos fenólicos fue clorogénica (60,8 µg/ml), mientras que la concentración más alta entre los compuestos flavonoides fue la hesperidina (1444,92 µg/ml). En resumen, los extractos de Gypsophila capillaris y H. salicornicum tienen una potente actividad anticancerígena contra las líneas celulares HepG-2 y MCF-7.

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.

4-Nitrochalcone as a potential drug in non-clinical breast cancer studies.

Breast cancer is a high-magnitude public health problem, continually challenging physicians and scientists worldwide in the field of drug therapy. 4-nitrochalcone (4NC) is a phenolic compound that has promising antitumor activity in vitro, but its application in breast cancer treatment is still poorly explored. This study aimed to evaluate the action of 4NC in vitro and in vivo breast cancer models. The cytotoxic potential of 4NC was tested towards MCF-7 and MDA-MD-231 breast cancer cells, with a lower impact in the non-tumor lineage HB4a. For in vivo studies, solid Ehrlich carcinoma (SEC) was used, a syngeneic mouse model with non-nuclear estrogen and progesterone positivity, characterized by immunohistochemistry. Daily oral administration of 4NC (25 mg kg-1) for 21 days led to a consistent reduction in tumor growth compared to the vehicle group. No signs of toxicity evaluated by hematological, biochemical, histological, and oxidative stress parameters were observed in mice, and the DL50 was >2000 mg kg-1. The effectors Raptor and S6K1 showed decreased activation, with a consequent reduction in protein synthesis; concomitantly, there was an increase in LC3-II levels, but the protective autophagic response was not completed, with the maintenance of p62 levels and cell death. These results open new possibilities for the use of 4NC as a tumor cell metabolism modulating agent.

Synthesis of Pyrrolo[3,4-b]pyridin-5-ones via Ugi-Zhu Reaction and In Vitro-In Silico Studies against Breast Carcinoma.

An Ugi-Zhu three-component reaction (UZ-3CR) coupled in a one-pot manner to a cascade process (N-acylation/aza Diels-Alder cycloaddition/decarboxylation/dehydration) was performed to synthesize a series of pyrrolo[3,4-b]pyridin-5-ones in 20% to 92% overall yields using ytterbium triflate as a catalyst, toluene as a solvent, and microwaves as a heat source. The synthesized molecules were evaluated in vitro against breast cancer cell lines MDA-MB-231 and MCF-7, finding that compound 1f, at a concentration of 6.25 µM, exhibited a potential cytotoxic effect. Then, to understand the interactions between synthesized compounds and the main proteins related to the cancer cell lines, docking studies were performed on the serine/threonine kinase 1 (AKT1) and Orexetine type 2 receptor (Ox2R), finding moderate to strong binding energies, which matched accurately with the in vitro results. Additionally, molecular dynamics were performed between proteins related to the studied cell lines and the three best ligands.

Untargeted LC-MS/MS Metabolomics Study of HO-AAVPA and VPA on Breast Cancer Cell Lines.

Breast cancer (BC) is one of the biggest health problems worldwide, characterized by intricate metabolic and biochemical complexities stemming from pronounced variations across dysregulated molecular pathways. If BC is not diagnosed early, complications may lead to death. Thus, the pursuit of novel therapeutic avenues persists, notably focusing on epigenetic pathways such as histone deacetylases (HDACs). The compound N-(2-hydroxyphenyl)-2-propylpentanamide (HO-AAVPA), a derivative of valproic acid (VPA), has emerged as a promising candidate warranting pre-clinical investigation. HO-AAVPA is an HDAC inhibitor with antiproliferative effects on BC, but its molecular mechanism has yet to be deciphered. Furthermore, in the present study, we determined the metabolomic effects of HO-AAVPA and VPA on cells of luminal breast cancer (MCF-7) and triple-negative breast cancer (MDA-MB-231) subtypes. The LC-MS untargeted metabolomic study allowed for the simultaneous measurement of multiple metabolites and pathways, identifying that both compounds affect glycerophospholipid and sphingolipid metabolism in the MCF-7 and MDA-MB-231 cell lines, suggesting that other biological targets were different from HDACs. In addition, there are different dysregulate metabolites, possibly due to the physicochemical differences between HO-AAVPA and VPA.

Selective cytotoxic effect of Annona muricata L. in HCC1954 (HER2+) breast cancer cells / Efecto citotóxico selectivo de Annona muricata L. en células HCC1954 (HER2+) de cáncer de mama

Annona muricata Linn. (Annonaceae) is a tropical plant with multiple beneficial health effects including anticancer properties. In breast cancer patients, overexpression of the HER2 oncoprotein corresponds to a poor prognosis, thus the main purpose of this study was to evaluate the cytotoxicity of ethanolic extracts from dried and fresh leaf of A. muricata on HER2+ breast cancer cells. MTT assays were performed and IC50 determined in HCC1954 (HER2+) cells, as well as in MCF7 (HER-) and peripheral blood mononuclear cells (PBMC) used as controls. Total polyphenol content evaluation and phytochemical screening were also performed. The cytotoxic effect of A. muricata extracts (125-1000 µg/mL) was dose-dependent and cell-type specific. The extracts exhibited higher cytotoxicity against HCC1954 than MCF7 cells, but weak toxicity against PBMC. This is the first report of the cytotoxic effect of A. muricata on HCC1954 cells, highlighting its potential for treating anti-estrogen-resistant breast cancers and low toxicity against PBMC.

Annona muricata Linn. (Annonaceae) es una planta tropical con múltiples efectos benéficos en la salud incluyendo propiedades antitumorales. En pacientes con cáncer de mama la sobreexpresión del oncogen HER2 corresponde a un mal pronóstico, por lo que el objetivo principal de este estudio fue evaluar la citotoxicidad de extractos etanólicos de hojas secas y frescas de A. muricata en células tumorales de mama HER2+. Se aplicaron pruebas de MTT y se determinaron IC50en células HCC1954 (HER2+); se utilizaron células MCF7 (HER-) y células mononucleares de sangre periférica (PBMC) como control. Se valoró también el contenido en polifenoles totales, y se realizó un tamizaje fitoquímico. El efecto citotóxico de los extractos de A. muricata (125-1000 µg/mL) fue dosis-dependiente y específico para cada tipo celular. Los extractos presentaron mayor actividad citotóxica contra HCC1954 en comparación con MCF7 y baja toxicidad contra PBMC. Este es el primer reporte del efecto citotóxico de A. muricata en HCC1954 y destaca su potencial terapéutico para tratamiento de cáncer de mama resistentes a antiestrógeno y baja citotoxicidad contra PBMC.

Effect of sitagliptin on down-regulation of KAT7 and SIRT1 gene expression in breast cancer cell line MCF7.

BACKGROUND: To date, the main clinical interest in DPP4 is focused on its inhibition in diabetic patients to prolong the half-life of incretins. Epigenetic alterations resulting from DPP4 inhibition have been poorly explored. OBJECTIVE: The objective of this study was to determine, whether sitagliptin, a DPP4 inhibitor, has effects on the expression of KAT7 and SIRT1 (genes encoding a histone acetyltransferase and a histone deacetylase, respectively) in MCF7 breast cancer cells, which play an essential role in modulating the epigenetic landscape of chromatin. MATERIAL AND METHODS: MCF7 cells were incubated for 20 h with sitagliptin at concentrations of 0.5, 1.0 and 2.0 µM. Total RNA was isolated and the relative mRNA expression of KAT7 and SIRT1 was determined by RT-qPCR. RESULTS: There was downregulation in the relative expression of both genes; for KAT7, downregulation reached up to 0.49 (p = 0.027) and for SIRT1, it reached up to 0.55 (p = 0.037). CONCLUSIONS: These results suggest that sitagliptin has effects on the histone epigenetic landscape. This topic deserves further study due to the current sample use of DPP4 inhibitors in diabetic patients.

ANTECEDENTES: Hasta la fecha, el principal interés clínico de la DPP4 se centra en su inhibición en pacientes diabéticos para prolongar la vida media de las incretinas. Las alteraciones epigenéticas resultantes de la inhibición de DPP4 han sido poco exploradas. OBJETIVO: Determinar si la sitagliptina, un inhibidor de DPP4, tiene efectos sobre la expresión de KAT7 y SIRT1 (genes que codifican una histona acetiltransferasa y una histona desacetilasa, respectivamente) en células de cáncer de mama MCF7, que desempeñan un papel esencial en la modulación del paisaje epigenético de la cromatina. MÉTODO: Las células MCF7 se incubaron durante 20 h con sitagliptina a concentraciones de 0.5, 1.0 y 2.0 µM. Se aisló el ARN total y se determinó la expresión relativa de ARNm de KAT7 y SIRT1 mediante RT-qPCR. RESULTADOS: Hubo una regulación a la baja en la expresión relativa de ambos genes; para KAT7, la regulación negativa alcanzó hasta 0.49 (p = 0.027) y para SIRT1 alcanzó hasta 0.55 (p = 0.037). CONCLUSIONES: Estos resultados sugieren que la sitagliptina tiene efectos sobre el paisaje epigenético de las histonas. Este tema merece más estudios debido al uso actual de inhibidores de DPP4 en pacientes diabéticos.

Non-natural amino acids into LfcinB-derived peptides: effect in their (i) proteolytic degradation and (ii) cytotoxic activity against cancer cells.

The dimeric peptide 26[F]: (RRWQWRFKKLG)2-K-Ahx has exhibited a potent cytotoxic effect against breast cancer cell lines, with position 26 (F) being the most relevant for anti-cancer activity. In this investigation, six analogues of the 26[F] peptide were synthesized in which the 26th position was replaced by non-natural hydrophobic amino acids, finding that some modifications increased the resistance to proteolytic degradation exerted by trypsin or pepsin. Additionally, these modifications increased the cytotoxic effect against breast cancer cells and generated cell death mediated by apoptosis pathways, activating caspases 8 and 9, and did not compromise the integrity of the cytoplasmic membrane. Finally, it was found that the modified peptides have a broad spectrum of action, since they also have a cytotoxic effect against the HeLa human cervical cancer cell line. Peptide 26[F] was inoculated in mice by ip administration and the lethal dose 50 (LD50) was between 70 and 140 mg kg-1. While for the 26[1-Nal]: (RRWQWR-1-Nal-KKLG)2-K-Ahx peptide, a dose-response test was performed, and the survival rate was 100%. These results suggested that these peptides are safe in this animal model and could be considered as promissory to develop a treatment against breast cancer.

ß-Carboline-α-aminophosphonate Derivative: A Promising Antitumor Agent for Breast Cancer Treatment.

Breast cancer is the most common type of cancer and the leading cause of cancer mortality among women worldwide. Considering the limitations of the current treatments available, we analyzed the in vitro cytotoxic potential of ((4-Fluoro-phenyl)-{2-[(1-phenyl-9H-ß-carboline-3-carbonyl)-amino]-ethylamino}-methyl)-phosphonic acid dibutyl ester (BCP-1) in breast cancer cells (MCF-7 and MDA-MB-231) and in a non-tumor breast cell line (MCF-10A). BCP-1 has an α-aminophosphonate unit linked to the ß-carboline nucleus, and the literature indicates that compounds of these classes have high biological potential. In the present study, the mechanism of action of BCP-1 was investigated through methods of spectrofluorimetry, flow cytometry, and protein expression analysis. It was found that BCP-1 inhibited the proliferation of both cancer cell lines. Furthermore, it induced oxidative stress and cell cycle arrest in G2/M. Upregulation of apoptosis-related proteins such as Bax, cytochrome C, and caspases, as well as a decrease in the anti-apoptotic protein Bcl-2, indicated potential induction of apoptosis in the MDA-MB-231 cells. While in MCF-7 cells, BCP-1 activated the autophagic death pathway, which was demonstrated by an increase in autophagic vacuoles and acidic organelles, in addition to increased expression of LC3I/LC3II and reduced SQSTM1/p62 expression. Further, BCP-1 demonstrated antimetastatic potential by reducing MMP-9 expression and cell migration in both breast cancer cell lines. In conclusion, BCP-1 is a promising candidate for breast cancer chemotherapy.

Doxorubicin-Loaded Iron Oxide Nanoparticles Induce Oxidative Stress and Cell Cycle Arrest in Breast Cancer Cells.

Cancer is one of the most common diseases nowadays and derives from the uncontrollable growth of a single cell. Magnetic nanoparticles (NpMag) offer various possibilities for use in the biomedical area, including drug delivery mediated by magnetic fields. In the current study, we evaluated the in vitro effects of iron-oxide magnetic nanoparticles conjugated with the antitumor drug doxorubicin (Dox) on human breast cancer cells. Our results revealed that magnetic nanoparticles with Dox (NpMag+Dox) induce cellular redox imbalance in MCF-7 cells. We also demonstrate that iron-oxide nanoparticles functionalized with Dox induce oxidative stress evidenced by DNA damage, lipid peroxidation, cell membrane disruption, and loss of mitochondria potential. As a result, NpMag+Dox drives MCF-7 cells to stop the cell cycle and decrease cell migration. The association of NpMg+Dox induced a better delivery of Dox to MCF cells, mainly in the presence of a magnetic field, increasing the death of MCF cells which might reduce the toxicity for healthy cells providing a better efficacy for the treatment. Thus, iron-oxide nanoparticles and doxorubicin conjugated may be candidate for anticancer therapy.

The Antiproliferative Activity of a Mixture of Peptide and Oligosaccharide Extracts Obtained from Defatted Rapeseed Meal on Breast Cancer Cells and Human Fibroblasts.

Oligosaccharide and peptide extracts obtained separately from defatted rapeseed meal (DRM) have shown antiproliferative activities on the MCF-7 breast cancer cell line. However, oligosaccharide extracts were not tested on human fibroblasts and have low yields. The objective of the present study was to combine two antiproliferative extracts, the peptides and oligosaccharides, that were obtained independently with commercial enzymes from DRM, allowing improvement of the mass yield and antiproliferative activity. The DRM was solubilized in an alkaline medium to obtain an insoluble meal residue (IMR) and an alkaline extract (RAE). To produce the oligosaccharide extract from IMR, three enzymes and different enzyme/substrate ratios were used. The oligosaccharide extract (molecular weight <30 kDa) recovered with the commercial enzyme. Endogalacturonase showed an 80% inhibition on MCF-7 cells at 20 mg/mL. The combination of this oligosaccharide extract with the peptide extract (obtained with Alkalase 2.4 L from a RAE at 10 mg/mL) inhibited 84.3% of MCF-7 cells proliferation at a concentration of 20 mg/mL, exhibiting no cytotoxic effects on fibroblasts. The mass yield of the extract pool was 27.07% (based on initial DRM). It can be concluded that a mixture of antiproliferative extracts was produced from DRM which was selective against MCF-7 cells.

The Aryl Hydrocarbon Receptor Ligand 6-Formylindolo(3,2-b)carbazole Promotes Estrogen Receptor Alpha and c-Fos Protein Degradation and Inhibits MCF-7 Cell Proliferation and Migration.

INTRODUCTION: Worldwide, breast cancer is the most common cancer in women and is the main cause of death among all neoplasia in this group. Luminal A breast cancer represents approximately 70% of all breast cancers and is treated with hormone therapies targeting estrogen receptor alpha (ERα). Unfortunately, patients develop drug resistance leading to recurrence of neoplasia due to estrogen-independent ERα reactivation. Therefore, it is crucial to identify new molecular targets downstream ERα signaling pathway that allows the implementation of better treatments to improve the outcome of breast cancer patients. Overexpression of c-Fos, an ERα gene target, has been associated with increased cell motility, malignancy, metastasis, and invasion while its neutralization results in decreased breast cancer tumorigenesis. The aryl hydrocarbon receptor (AHR) ligands halogenated and polycyclic aromatic hydrocarbons, highly toxic compounds, down regulate c-Fos and ERα levels. The present study aimed to evaluate whether 6-formylindolo(3,2-b)carbazole (FICZ), a no toxic AHR agonist, modifies c-Fos levels in MCF-7 mammary carcinoma cells as well as to determine its effects on cell proliferation and migration. In addition, the possible mechanism through which FICZ mediates c-Fos levels in MCF-7 cells was investigated. METHODS: Initially, the effect of FICZ on c-Fos mRNA and protein levels in MCF-7 cells, untreated or treated with estradiol, was evaluated by qPCR and Western blot. 2,3,7,8-Tetrachloro-dibenzo-p-dioxin, an AHR prototype agonist, was used as a positive control. Next, we examined the effect of FICZ on MCF-7 cell proliferation and migration by cell counting, MTT, 3H-thymidine incorporation, and scratch-wound assays. Finally, the involvement of proteasome 26S on ERα and c-Fos protein degradation was investigated by the use of MG132 and Western blot. RESULTS: The data show that FICZ treatment downregulates c-Fos mRNA and protein levels, most likely by promoting ERα proteasome degradation, blocking MCF-7 cell proliferation and migration. The results also demonstrate that liganded ERα was required for FICZ-mediated ERα degradation. CONCLUSIONS: Activation of AHR results in a decreased MCF-7 cell proliferation and migration by ERα and c-Fos down regulation. Targeting AHR might be a promising therapy for breast cancer treatment, particularly when estrogen-independent ERα reactivation presents.

Chicken embryo model for in vivo acute toxicological and antitumor efficacy evaluation of lipid nanocarrier containing doxorubicin.

Nanoencapsulation of chemotherapeutics, including doxorubicin, can endow the formulations with unique properties, such as a decrease in adverse effects and toxicity. The chicken embryo model is an alternative and well-accepted strategy for evaluating the toxicity and efficacy of drugs and nanoformulations. Therefore, this study proposes the development of a new lipid nanocarrier for doxorubicin delivery (NanoLip-Dox) and posterior evaluation of toxicological profile and antitumoral efficacy against a breast tumor in chicken embryos. NanoLip-Dox showed a unimodal particle size (< 150 nm), negative zeta potential (-19.5 mV), absence of drug crystals, drug content of 0.099 mg·mL-1, and high entrapment efficiency (95%). NanoLip-Dox did not cause toxicity in the chicken embryos; in contrast, doxorubicin hydrochloride induced moderate irritation in the chorioallantoic membrane (at 862.1 µmol·L-1), a survival rate of 50% (at 1.7 µmol·L-1), and an increase in aspartate aminotransferase (at 862.1, 344.8, and 172.4 µmol·L-1). In addition, NanoLip-Dox (at 1.7 µmol·L-1) showed potent antitumor efficacy with a high tumor remission percentage (40.9 ± 9.7%) compared to the control group (8.6 ± 14.8%). These findings together with the absence of toxicity concerning morphological characteristics, weights of embryos and organs, hematologic parameters, and enzymatic activity (alanine aminotransferase, aspartate aminotransferase, and creatinine) suggest the safety and efficacy of NanoLip-Dox.