Differential DNA methylation and CTCF binding between the ESR1 promoter a of MCF-7 and MDA-MB-231 breast cancer cells.

BACKGROUND: ESR1 is expressed by 60-70% of breast tumours. it's a good prognosis factor and the target of hormone therapy. Optimization of ESR1 reactivation therapy is currently ongoing. Here we probe if the transcription factor CTCF plays a role in the differential expression of ESR1 in the breast cancer cell lines MCF-7 (ESR1+) and MDA-MB-231 (ESR1-). METHODS AND RESULTS: Knockdown of CTCF in MCF-7 resulted in decreased ESR1 gene expression. CTCF binds to the promoter of ESR1 in MCF-7 but not in MDA-MB-231 cells. CTCF ESR1 binding sites are unmethylated in MCF7 but methylated in MDA-MB-231 cells. CONCLUSION: ESR1 expression in MCF7 cells is dependent on CTCF expression. CTCF can bind to specific regions of the promotor of ESR1 gene in MCF-7 cells but not in MDA-MB-231 cells, this correlates with the methylation status of these regions and could be involved in the transcriptional regulation of ESR1.

The effect of cilostazol on the platelet-derived growth factor-beta/beta isoform reduction on venous hyperplasia in an experimental balloon-induced injury model.

BACKGROUND: Intimal hyperplasia is the response to endothelial injury. Platelet-derived growth factor is released early and favors the formation of intimal hyperplasia. Although multiple treatments, from open surgery to endovascular techniques, have been used they remain controversial. There is currently interest in developing pharmacological strategies to address this pathology. Local vascular inflammation induced by vessel barotrauma generates intimal hyperplasia due to mechanical stress over the venous endothelium. Cilostazol is a selective phosphodiesterase type 3 (PDE3) selective inhibitor with a regulatory effect over intimal hyperplasia. The objective was to investigate cilostazol's role in inhibiting smooth muscle cell proliferation due to changes in the expression and release of PDGF-BB isoform and the effect on developing IH using an experimental model of vascular barotrauma (balloon-induced injury model). METHODS: We included 12 New Zealand rabbits. The balloon-induced injury model (BIIM) and experimental group cilostazol (20 mg/kg/day) included 6 rabbits each. Contralateral veins from 6 rabbits used in BIIM model has been taken as control group. We measured and compared the expression of PDGF-BB and the development of IH. A pathologist board chooses a PDGFRα antibody to localized its expression by immunohistochemistry analysis. Subsequently, using an automated immunohistochemical staining machine, the PDGFR expression was evaluated using a Zeiss Primo Star 4 light microscope. RESULTS: The measurement obtained in the intimal layer was: 126.12 µm2 in the CG, 232 µm2 in the BIIM group, and 178 µm2 in the EG. A statistically significant difference was observed. Baseline serum concentrations of PDGF-BB in the BIIM group were 0.22 pg/mL. At 12 h 0.42 pg/mL, and 0.17 pg/mL at seven days. In the experimental group, the basal levels were 0.33 pg/mL. With the use of cilostazol, a lower peak was obtained at 12 h (0.08 pg/mL). This difference was statistically significant. CONCLUSIONS: Cilostazol induced a significant reduction of IH caused by barotrauma in the venous endothelium, which correlates with decrease in the PDGF-BB in serum. This could be attributed to the pharmacologic effect on PDGFR expression.

Evaluations of Anticancer Effects of Combinations of Cisplatin and Tirucallane-Type Triterpenes Isolated from Amphipterygium adstringens (Schltdl).

The cytotoxic activity of combinations of masticadienonic (AMD) or 3αOH-hydroxy-masticadienonic (3αOH-AMD) acids with cisplatin (CDDP) was evaluated against PC3 prostate and HCT116 colon cancer cell lines. Combinations A (half the IC50 value), B (IC50 value), and C (twice the IC50 value) were tested at a 1 : 1 ratio. All AMD plus CDDP combinations demonstrated increased cytotoxic effect, as determined by the sulforhodamine B test, in both cell types. The best combination was B, which showed 93 % and 91 % inhibition of the proliferation of PC3 and HCT116 cells, respectively. It also increased apoptosis in the PC3 cell lines, as evaluated by flow cytometry. However, in vivo tests showed no additional activity from the AMD plus CDDP combinations. These results showed that the increased cytotoxic activity of the combinations in vitro did not reflect in vivo tests. All combinations of 3αOH-AMD plus CDDP exerted antagonistic effects in both cell types.

Endothelium-Dependent Induction of Vasculogenic Mimicry in Human Triple-Negative Breast Cancer Cells Is Inhibited by Calcitriol and Curcumin.

In highly aggressive tumors, cancer cells may form channel-like structures through a process known as vasculogenic mimicry (VM). VM is generally associated with metastasis, mesenchymal phenotype, and treatment resistance. VM can be driven by antiangiogenic treatments and/or tumor microenvironment-derived factors, including those from the endothelium. Curcumin, a turmeric product, inhibits VM in some tumors, while calcitriol, the most active vitamin D metabolite, exerts potent antineoplastic effects. However, the effect of these natural products on VM in breast cancer remains unknown. Herein, we studied the effect of both compounds on triple-negative breast cancer (TNBC) VM-capacity in a co-culture model. The process of endothelial cell-induced VM in two human TNBC cell lines was robustly inhibited by calcitriol and partially by curcumin. Calcitriol promoted TNBC cells' morphological change from spindle-like to cobblestone-shape, while curcumin diminished VM 3D-structure. Notably, the treatments dephosphorylated several active kinases, especially those involved in the PI3K/Akt pathway. In summary, calcitriol and curcumin disrupted endothelium-induced VM in TNBC cells partially by PI3K/Akt inactivation and mesenchymal phenotype inhibition. Our results support the possible use of these natural compounds as adjuvants for VM inactivation in patients with malignant tumors inherently capable of forming VM, or those with antiangiogenic therapy, warranting further in vivo studies.

Low-Density Granulocytes and Neutrophil Extracellular Traps as Biomarkers of Disease Activity in Adult Inflammatory Myopathies.

BACKGROUND/OBJECTIVE: Biomarkers for disease activity and damage accrual in idiopathic inflammatory myopathies (IIMs) are currently lacking. The purpose of this cross-sectional study is to analyze the relationship among low-density granulocytes (LDGs), neutrophil extracellular traps (NETs), and clinical and immunological features of patients with IIM. METHODS: We assessed disease activity, damage accrual, amount of LDGs, NETs, expression of LL-37, and serum cytokines in 65 adult patients with IIM. Differences between groups and correlations were assessed by Kruskal-Wallis, Mann-Whitney U, and Spearman ρ tests. The association between LDGs, NETs, disease activity, calcinosis, and cutaneous ulcers was assessed by logistic regression. To address the capacity of LDGs and NETs to diagnose disease activity, we used receiving operating characteristic curves. RESULTS: Low-density granulocytes were higher in patients with active disease, ulcers, calcinosis, and anti-MDA5 antibodies, which correlated with serum levels of IL-17A and IL-18. Neutrophil extracellular traps were higher in patients with calcinosis, elevated titers of antinuclear antibodies, and positive anti-PM/Scl75 tests. The combination of a high proportion of both total LDGs and NETs was associated with the presence of calcinosis and cutaneous ulcers. LL-37 was higher in NETs originating from LDGs. Normal-density neutrophils were elevated in patients with active dermatomyositis. CONCLUSIONS: Low-density granulocytes and NETs containing LL-37 are increased in patients with IIM and active disease, and correlate with proinflammatory cytokines. Both total and CD10+ LDGs are potential biomarkers for disease activity and, in combination with NETs, have the potential to detect patients who are at risk for cutaneous ulcers and calcinosis.

The Effects of COVID-19 on Healthcare Workers and Non-Healthcare Workers in Mexico: 14 Months into the Pandemic.

Background and Objectives: Healthcare workers (HCWs) play important roles in mitigating the COVID-19 pandemic and are more likely to become infected with COVID-19. Mexico, among other countries, had a high incidence and prevalence of cases and deaths from this disease. Material and Methods: This retrospective study evaluated the clinical characteristics as well as the geographical distribution of cases, deaths, and active cases of COVID-19 in HCWs and non-HCWs using official information from the Ministry of Health of Mexico. Results: A total of 235,343 cases of COVID-19 were reported in healthcare workers, and 2,094,191 cases were reported in non-healthcare workers. A total of 76.0% of cases in healthcare workers occurred in those who were between 25 and 50 years of age, and 71.4% of deaths occurred in those who were 50 to 69 years of age. Among healthcare workers, the most frequent comorbidities were obesity (15.2%), hypertension (10.9%), and diabetes (6.8%). Nurses were the group with the most cases (39.7%), followed by other healthcare workers (30.6%), physicians (26%), and dentists (1.6%). Physicians were the group with the most deaths (46%), followed by other professionals (30%), nurses (19%), and dentists (3%). Conclusion: These findings are likely the result of healthcare workers in Mexico being at a greater risk of exposure to SARS-CoV-2.

A Higher Frequency Administration of the Nontoxic Cycloartane-Type Triterpene Argentatin A Improved Its Anti-Tumor Activity.

Parthenium argentatum (Gray), commonly known as guayule, has been used to obtain natural rubber since the beginning of the 20th century. Additionally, the so called "resin" is a waste product derived from the industrial process. The cycloartane-type triterpene Argentatin A (AA) is one of the main constituents of the industrial waste resin. In this study we evaluated the AA anticancer activity both in vitro and in vivo in the HCT116 colon cancer cells. The apoptosis promotion of AA was assessed by the annexin V/propidium iodide (PI) assay. The senescence was evaluated for SA-ß-galactosidase, and PCNA was used as a marker of proliferation. Its antitumor activity was evaluated using a xenograft mouse model. The results indicated that AA-induced apoptosis in HCT-116 cells and was positively stained for SA-ß-galactosidase. In the xenografted mice test, the administration of AA at the dose of 250 mg/kg three times a week for 21 days reduced tumor growth by 78.1%. A comparable tumor reduction was achieved with cisplatin at the dose of 2 mg/kg administered three times a week for 21 days. However, nude mice treated with AA did not lose weight, as they did remarkably when treated with cisplatin. Furthermore, the animals treated with AA showed similar blood profiles as the healthy control group. These data indicate the low toxicity of AA compared to that shown by cisplatin.

Glucocorticoid-dependent expression of IAP participates in the protection against TNF-mediated cytotoxicity in MCF7 cells.

BACKGROUND: Glucocorticoid receptor (GR) activation has been associated with breast cancer cell survival in vitro. Glucocorticoid (GC)-dependent protection against tumor necrosis factor (TNF)-induced cell death has been well characterized in MCF7 luminal A breast cancer cells. The GR activates a variety of protective mechanisms, such as inhibitors of apoptosis proteins (IAPs). However, the relative contribution of the GR-dependent expression of IAPs in the protection of cell death has not, to our knowledge, been evaluated. METHODS: MCF7 cells were used for all experiments. GR was activated with cortisol (CORT) or dexamethasone (DEX) and inhibited with mifepristone (RU486). Cell viability was determined in real-time with the xCELLigence™ RTCA System and at specific endpoints using crystal violet stain. The mRNA levels of the eight members of the IAP family were measured by qRT-PCR. The protein levels of GR, PR, ERα, HER2, PARP1, c-IAP1 and XIAP were evaluated by Western blot analysis. The knockdown of c-IAP1 and XIAP was accomplished via transient transfection with specific siRNAs. GR activation was verified by a gene reporter assay. Via the cBioportal interphase we queried the mRNA levels of GR and IAPs in breast cancer tumors. RESULTS: RU486 significantly inhibited the anti-cytotoxic effect of both GCs. PARP1 processing was diminished in the presence of both GCs. The combined treatments of GCs + TNF increased the relative mRNA levels of Survivin>c-IAP1 > NAIP>Apollon>XIAP>Ts-IAP > ML-IAP > c-IAP2. Additionally, GR mRNA content increased with the combined treatments of GCs + TNF. Sustained levels of the proteins c-IAP1 and XIAP were observed after 48 h of the combined treatments with GCs + TNF. With c-IAP1 and XIAP gene silencing, the GC-mediated protection was diminished. In the breast tumor samples, the GR mRNA was coexpressed with Apollon and XIAP with a Pearson coefficient greater than 0.3. CONCLUSIONS: The effect of GCs against TNF-mediated cytotoxicity involves increased mRNA expression and sustained protein levels of c-IAP1 and XIAP. The antagonist effects of RU486 and the qRT-PCR results also suggest the role of the GR in this process. This finding may have clinical implications because the GR and IAPs are expressed in breast tumor samples.

Effect of imatinib on plasma glucose concentration in subjects with chronic myeloid leukemia and gastrointestinal stromal tumor.

BACKGROUND: Type 2 diabetes mellitus has become one of the most important public health concerns worldwide. Due to its high prevalence and morbidity, there is an avid necessity to find new therapies that slow the progression and promote the regression of the disease. Imatinib mesylate is a tyrosine kinase inhibitor that binds to the Abelson tyrosine kinase and related proteins. It enhances ß-cell survival in response to toxins and pro-inflammatory cytokine. The aim of this study is to evaluate the effect of imatinib on fasting plasma glucose in subjects with normal fasting glucose, subjects with impaired fasting glucose and in subjects with type 2 diabetes mellitus. METHODS: We identified 284 subjects diagnosed with chronic myeloid leukemia or gastrointestinal stromal tumors from the Instituto Nacional de Ciencias Medicas y Nutricion Salvador Zubiran database. 106/284 subjects were treated with imatinib. We compared the effect of imatinib on fasting plasma glucose after 1 and 6 months of treatment. We used ANOVA test of repeated samples to determine statistical significance in fasting plasma glucose before imatinib treatment and the follow-up. Statistical analysis was performed with Statistical Package for the Social Sciences v22. RESULTS: We included a total of 106 subjects: 76 with fasting plasma glucose concentrations < 100 mg/dL (normal FG), 19 subjects with fasting plasma glucose concentrations ≥100 mg/dL (impaired fasting glucose), and 11 subjects with ≥126 mg/dL (type 2 diabetes mellitus). We found a significant increase in fasting plasma glucose concentration in the normal fasting glucose group (p = 0.048), and a significant decrease in fasting plasma glucose concentration in the type 2 diabetes mellitus group (p = 0.042). In the impaired fasting glucose group, we also found a tendency towards a decrease in fasting plasma glucose (p = 0.076). We identified 11 subjects with type 2 diabetes mellitus, of whom, 7 (64%) had a reduction in their fasting plasma glucose concentrations after 6 months. A significant glycosylated hemoglobin reduction (p = 0.04) was observed. CONCLUSION: Subjects with chronic myeloid leukemia or gastrointestinal stromal tumor with type 2 diabetes mellitus had a significant reduction in fasting plasma glucose and glycosylated hemoglobin at 1 and 6 months while using imatinib.

Masticadienonic and 3α-OH Masticadienoic Acids Induce Apoptosis and Inhibit Cell Proliferation and Tumor Growth in Prostate Cancer Xenografts in Vivo.

The triterpenes have been constituted as a group of interesting molecules as possible antitumor agents. Despite several of them not presenting a potent cytotoxic activity in vitro against cancer cells, in vivo in xenotransplant tumors studies, they show promising results. Based on the above considerations, we investigated the antitumor activity of both masticadienonic (MDA) and 3α-OH masticadienoic (3α-OH MDA) acids in a mouse prostate cancer xenograft model. Immunohistochemical assays were used to evaluate the decrease in the expression of the Proliferating Cell Nuclear Antigen (PCNA) and the Ki-67 induced by MDA and 3α-OH MDA. Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay was performed to demonstrate the fragmentation of DNA. Our results showed that the two triterpenes inhibited tumor growth, had anti-proliferative effect in vivo and induced cell death by apoptosis. Collectively, our data suggested that the antitumor mechanism of MDA and 3α-OH MDA involves several molecular targets related to cell proliferation and apoptosis.

Primary breast cancer cell culture yields intra-tumor heterogeneous subpopulations expressing exclusive patterns of receptor tyrosine kinases.

BACKGROUND: It has become evident that intra-tumor heterogeneity of breast cancer impact on several biological processes such as proliferation, migration, cell death and also might contribute to chemotherapy resistance. The expression of Receptor Tyrosine Kinases (RTKs) has not been analyzed in the context of intra-tumor heterogeneity in a primary breast cancer cell culture. Several subpopulations were isolated from the MBCDF (M serial-breast cancer ductal F line) primary breast cancer cells and were successfully maintained in culture and divided in two groups according to their morphology and RTKs expression pattern, and correlated with biological processes like proliferation, migration, anchorage-independent cell growth, and resistance to cytotoxic chemotherapy drugs and tyrosine kinase inhibitors (TKIs). METHODS: Subpopulations were isolated from MBCDF primary breast cancer cell culture by limiting dilution. RTKs and hormone receptors were examined by Western blot. Proliferation was measure by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl-tetrazolium bromide (MTT assay). Cell viability was evaluated by Crystal Violet. Migration was assessed using Boyden chambers. Anchorage-independent cell growth was evaluated by colony formation in soft agar. RESULTS: Several subpopulations were isolated from the MBCDF breast cancer cells that were divided into two groups according to their morphology. Analysis of RTKs expression pattern showed that HER1, HER3, c-Met and VEGFR2 were expressed exclusively in cells from group 1, but not in cells from group 2. PDGFR was expressed only in cells from group 2, but not in cells from group 1. HER2, HER4, c-Kit, IGF1-R were expressed in all subpopulations. Biological processes correlated with the RTKs expression pattern. Group 2 subpopulations present the highest rate of cell proliferation, migration and anchorage-independent cell growth. Analysis of susceptibility to chemotherapy drugs and TKIs showed that only Paclitaxel and Imatinib behaved differently between groups. Group 1-cells were resistant to both Paclitaxel and Imatinib. CONCLUSIONS: We demonstrated that subpopulations from MBCDF primary cell culture could be divided into two groups according to their morphology and a RTKs excluding-expression pattern. The differences observed in RTKs expression correlate with the biological characteristics and chemoresistance of each group. These results suggest that intra-tumor heterogeneity contributes to generate groups of subpopulations with a more aggressive phenotype within the tumor.

[Characterization of hemodynamic ex vivo model to study endothelial activation by TNF-α in prefunded human veins]. / Caracterización de un modelo hemodinámico ex vivo para el estudio de la activación endotelial por el factor de necrosis tumoral α (TNF-α) en venas humanas perfundidas.

Inflammation is recognized as part of the etiology of numerous diseases. The interaction among cells of the immunological system with local cells and molecules, such as cytokines and chemokines, allows cellular activation and response amplification. The importance of several physicochemical factors like frictional force, vascular flow, shear stress, and pressure is now recognized because they are known to modulate genetic expression and endothelial activation; however, there are very few studies that recreate such cellular microenvironments. Hence, it is of paramount importance to develop new models that will mimic physiological conditions. Our aim was to improve a human vein ex vivo model that would allow endothelial activation in flow conditions, to study the molecular components during adhesion, taking into consideration physicochemical parameters such as flow and shear stress. Endothelial umbilical human vein was used and activated with TNF-a in order to determine U937 monocytic cells adhesion, as well as cytokines secretion and ICAM-1 expression. This model will allow leukocyte adhesion studies, using different inflammatory stimulus, along with the signaling pathways involved in several pathologies.

Development of a Redox-Polymer-Based Electrochemical Glucose Biosensor Suitable for Integration in Microfluidic 3D Cell Culture Systems.

The inclusion of online, in situ biosensors in microfluidic cell cultures is important to monitor and characterize a physiologically mimicking environment. This work presents the performance of second-generation electrochemical enzymatic biosensors to detect glucose in cell culture media. Glutaraldehyde and ethylene glycol diglycidyl ether (EGDGE) were tested as cross-linkers to immobilize glucose oxidase and an osmium-modified redox polymer on the surface of carbon electrodes. Tests employing screen printed electrodes showed adequate performance in a Roswell Park Memorial Institute (RPMI-1640) media spiked with fetal bovine serum (FBS). Comparable first-generation sensors were shown to be heavily affected by complex biological media. This difference is explained in terms of the respective charge transfer mechanisms. Under the tested conditions, electron hopping between Os redox centers was less vulnerable than H2O2 diffusion to biofouling by the substances present in the cell culture matrix. By employing pencil leads as electrodes, the incorporation of these electrodes in a polydimethylsiloxane (PDMS) microfluidic channel was achieved simply and at a low cost. Under flow conditions, electrodes fabricated using EGDGE presented the best performance with a limit of detection of 0.5 mM, a linear range up to 10 mM, and a sensitivity of 4.69 µA mM-1 cm-2.

Differential histological features and myogenic protein levels in distinct muscles of d-sarcoglycan null muscular dystrophy mouse model.

Skeletal muscle (SkM) comprises slow and fast-twitch fibers, which differ in molecular composition, function, and systemic energy consumption. In addition, muscular dystrophies (DM), a group of diverse hereditary diseases, present different patterns of muscle involvement, progression, and severity, suggesting that the regeneration-degeneration process may differ depending on the muscle type. Therefore, the study aimed to explore the expression of proteins involved in the repair process in different muscles at an early stage of muscular dystrophy in the δ-sarcoglycan null mice (Sgcd-null), a limb-girdle muscular dystrophy 2 F model. Hematoxylin & Eosin (H&E) Staining showed a high number of central nuclei in soleus (Sol), tibialis (Ta), gastrocnemius (Gas), and extensor digitorum longus (Edl) from four months Sgcd-null mice. However, fibrosis, determined by trichrome of Gomori modified staining, was only observed in Sgcd-null Sol. In addition, the number of Type I and II fibers variated differentially in the Sgcd-null muscles vs. wild-type muscles. Besides, the protein expression level of ß-catenin, myomaker, MyoD, and myogenin also presented different expression levels in all the Sgcd-null muscles studied. In summary, our study reveals that muscles with different metabolic characteristics showed distinct expression patterns of proteins involved in the muscle regeneration process. These results could be relevant in designing therapies for genetic and acquired myopathy.

The Protective Role of Cranberries and Blueberries in Oral Cancer.

BACKGROUND: Oral cancer has a high prevalence worldwide, and this disease is caused by genetic, immunological, and environmental factors. The main risk factors associated with oral cancer are smoking and alcohol. RESULTS: There are various strategies to reduce risk factors, including prevention programs as well as the consumption of an adequate diet that includes phytochemical compounds derived from cranberries (Vaccinium macrocarpon A.) and blueberries (Vaccinium corymbosum L.); these compounds exhibit antitumor properties. RESULTS: The main outcome of this review is as follows: the properties of phytochemicals derived from cranberries were evaluated for protection against risk factors associated with oral cancer. CONCLUSIONS: The secondary metabolites of cranberries promote biological effects that provide protection against smoking and alcoholism. An alternative for the prevention of oral cancer can be the consumption of these cranberries and blueberries.

A novel nonsense mutation in the insulin receptor gene in a patient with HAIR-AN syndrome and endometrial cancer.

Severe insulin resistance can be caused by rare genetic defects in the insulin receptor known as insulin receptoropathies. These genetic defects cause a wide spectrum of clinical manifestations ranging from mild syndromes to lethal disorders. Among those is the HAIR-AN an extreme subtype of polycystic ovary syndrome (PCOS). We present a case of a 29-year-old woman with amenorrhea, severe insulin resistance, hirsutism, and acanthosis nigricans who also developed endometrial cancer. She was found to carry a novel heterozygous nonsense mutation insulin receptor gene (INSR). The mutation was inherited from the mother. Levels of insulin receptor and AKT were measured using Western-Blot from peripheral blood mononuclear cells and were both decreased. Thus, we conclude that the identified mutation in the insulin receptor gene and lead to decreased activity of the downstream signaling of the insulin pathway.

Reversal of multidrug resistance by morning glory resin glycosides in human breast cancer cells.

Reversal of multidrug resistance (MDR) by thirty resin glycosides from the morning glory family (Convolvulaceae) was evaluated in vinblastine-resistant human breast carcinoma cells (MCF-7/Vin). The effects of these amphipathic compounds on the cytotoxicity and P-glycoprotein (P-gp)-mediated MDR were estimated with the sulforhodamine B colorimetric assay. Active noncytotoxic compounds exerted a potentiation effect of vinblastine susceptibility by 1- to over 1906-fold at tested concentrations of 5 and 25 µg/mL. Murucoidin V (1) enhanced vinblastine activity 255-fold when incorporated at 25 µg/mL and also, based on flow cytometry, significantly increased the intracellular accumulation of rhodamine 123 with the use of reserpine as a positive control for a MDR reversal agent. Incubation of MCF-7/Vin cells with 1 caused an increase in uptake and notably lowered the efflux rate of rhodamine 123. Decreased expression of P-glycoprotein by compound 1 was detected by immunofluorescence flow cytometry after incubation with an anti-P-gp monoclonal antibody. These results suggest that resin glycosides represent potential efflux pump inhibitors for overcoming MDR in cancer therapy.

Casiopeina II-gly and bromo-pyruvate inhibition of tumor hexokinase, glycolysis, and oxidative phosphorylation.

The copper-based drug Casiopeina II-gly (CasII-gly) shows potent antineoplastic effect and diminishes mitochondrial metabolism on several human and rodent malignant tumors. To elucidate whether CasII-gly also affects glycolysis, (a) the flux through the complete pathway and the initial segment and (b) the activities of several glycolytic enzymes of AS-30D hepatocarcinoma cells were determined. CasII-gly (IC50 = 0.74-6.7 µM) was more effective to inhibit 24-72 h growth of several human carcinomas than 3-bromopyruvate (3BrPyr) (IC50 = 45-100 µM) with no apparent effect on normal human-proliferating lymphocytes and HUVECs. In short-term 60-min experiments, CasII-gly increased tumor cell lactate production and glycogen breakdown. CasII-gly was 1.3-21 times more potent than 3BrPyr and cisplatin to inhibit tumor HK. As CasII-gly inhibited the soluble and mitochondrial HK activities and the flux through the HK-TPI glycolytic segment, whereas PFK-1, GAPDH, PGK, PYK activities and HPI-TPI segment flux were not affected, the data suggested glycogenolysis activation induced by HK inhibition. Accordingly, glycogen-depleted as well as oligomycin-treated cancer cells became more sensitive to CasII-gly. The inhibition time-course of HK by CasII-gly was slower than that of OxPhos in AS-30D cells, indicating that glycolytic toxicity was secondary to mitochondria, the primary CasII-gly target. In long-term 24-h experiments with HeLa cells, 5 µM CasII-gly inhibited OxPhos (80%), glycolysis (40%), and HK (42%). The present data indicated that CasII-gly is an effective multisite anticancer drug simultaneously targeting mitochondria and glycolysis.

(-) - Epicatechin improves Tibialis anterior muscle repair in CD1 mice with BaCl2-induced damage.

Several studies have shown the beneficial effect that Epicatechin (Epi) has on the skeletal muscle of murine models and patients with muscular dystrophy and in the muscles of patients with diabetes or murine sarcopenia models. This flavanol has been shown to enhance antioxidant pathways and improve muscle architecture. However, the repair process during muscle regeneration has not been analyzed. To address this, we characterize the effect of Epi in the repair process of the Tibialis anterior in a murine model with BaCl2-induced damage. CD1 mice of 10 weeks of age were randomly selected and injured with BaCl2. One hour later, they were divided into four groups (n=6 for histology groups and n=12 for western blot groups). Epi was administered every 12h, until the time of sacrifice. Histological and morphological analysis showed that Epi significantly reduced the area of damage and hypertrophy at 15 days in the damaged muscle. Furthermore, western blot assays showed that the treatment increases ß-catenin (active) and myogenic proteins such as MyoD and Myogenin. These results show that Epi exerts therapeutic effects accelerating skeletal muscle repair after induced damage chemically, thus highlighting the therapeutic potential of this flavanol in different myopathies.

Gene Promoter-Methylation Signature as Biomarker to Predict Cisplatin-Radiotherapy Sensitivity in Locally Advanced Cervical Cancer.

Despite efforts to promote health policies focused on screening and early detection, cervical cancer continues to be one of the leading causes of mortality in women; in 2020, estimated 30,000 deaths in Latin America were reported for this type of tumor. While the therapies used to treat cervical cancer have excellent results in tumors identified in early stages, those women who are diagnosed in locally advanced and advanced stages show survival rates at 5 years of <50%. Molecular patterns associated with clinical response have been studied in patients who present resistance to treatment; none of them have reached clinical practice. It is therefore necessary to continue analyzing molecular patterns that allow us to identify patients at risk of developing resistance to conventional therapy. In this study, we analyzed the global methylation profile of 22 patients diagnosed with locally advanced cervical cancer and validated the genomic results in an independent cohort of 70 patients. We showed that BRD9 promoter region methylation and CTU1 demethylation were associated with a higher overall survival (p = 0.06) and progression-free survival (p = 0.0001), whereas DOCK8 demethylation was associated with therapy-resistant patients and a lower overall survival and progression-free survival (p = 0.025 and p = 0.0001, respectively). Our results suggest that methylation of promoter regions in specific genes may provide molecular markers associated with response to treatment in cancer; further investigation is needed.