395 research outputs found

    Arsenic trioxide-induced cytotoxicity in small cell lung cancer via altered redox homeostasis and mitochondrial integrity.

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    Arsenic trioxide (ATO) has demonstrated anticancer activity in different malignancies, especially acute promyelocytic leukemia, with a wide array of putative mechanisms. In this study, we aimed to elucidate the activity and mechanisms of ATO in small cell lung cancer (SCLC). A panel of SCLC cell lines (H841, DMS79, H526, H69 and H187) was employed to demonstrate the activity of ATO. Cell viability, apoptosis and mitochondrial membrane depolarization were assessed. Western blotting was performed to determine the alteration of pro-apoptotic and anti-apoptotic mediators. Reactive oxygen species (ROS) (hydrogen peroxide and superoxide) and intracellular glutathione (GSH) were measured. Antioxidants, N-acetyl-L-cysteine (NAC) and butylated hydroxyanisole (BHA), were applied to restore GSH content and reduce production of ROS. All SCLC cell lines were relatively sensitive to ATO with IC50 values below 10 µM. ATO induced cell death mainly through apoptosis in H841 cells in a dose-dependent manner. Hydrogen peroxide was the major ROS in SCLC cells induced by ATO. Along with GSH depletion and Bcl-2 downregulation, mitochondrial membrane permeabilization was enhanced, followed by release of AIF and SMAC from mitochondria to initiate different cell death pathways. NAC reversed cell death and molecular changes induced by ATO via restoring GSH and reducing ROS content. BHA inhibited hydrogen peroxide production completely and partially restored GSH content accounting for partial reversal of cell inhibition and mitochondrial dysfunction. Nonetheless, ATO reduced both reduced and oxidized form of thioredoxin 1 (Trx1) with no effect on Trx1 redox potential. ATO led to cell death in SCLC mainly through mitochondrial dysfunction, resulting from altered cellular redox homeostasis, namely, hydrogen peroxide generation, GSH depletion and Trx1 downregulation.published_or_final_versio

    The Effect of Tumor Microenvironment on Autophagy and Sensitivity to Targeted Therapy in EGFR-Mutated Lung Adenocarcinoma

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    Lung cancer is the top cancer killer worldwide. Tyrosine kinase inhibitors (TKIs), for example erlotinib, are commonly used to target epidermal growth factor receptor (EGFR)-mutated lung adenocarcinoma (ADC). Autophagy is a cellular response to stress, serving as a protective mechanism during anticancer therapy. The tumor microenvironment (TME) is composed of non-tumor cells that include fibroblasts. Our study aimed to investigate the effect of TME on autophagy and TKI sensitivity. Following cell sorting after direct co-culturing, autophagy and cytokine production were observed in both HCC827 and MRC-5 cells. The synergistic combination of erlotinib and chloroquine (autophagy inhibitor) was observed under TME. Tumor growth was significantly suppressed with combined erlotinib/chloroquine compared with erlotinib in HCC827 xenografts.published_or_final_versio

    E2F1 Downregulation by Arsenic Trioxide in Lung Adenocarcinoma

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    Lung cancer is one of the most common cancers worldwide. Arsenic trioxide (ATO) has been approved by the U.S. Food and Drug Administration for the treatment of acute promyelocytic leukemia. Nonetheless preliminary data have suggested potential activity of ATO in solid tumors including lung cancer. This study aimed to examine the underlying mechanisms of ATO in the treatment of lung adenocarcinoma. Using a panel of 7 lung adenocarcinoma cell lines, the effects of ATO treatment on cell viability, expression of E2F1 and its downstream targets, phosphatidylserine externalization, mitochondrial membrane depolarization and alteration of apoptotic/anti-apoptotic factors were studied. Tumor growth inhibition in vivo was investigated using a nude mouse xenograft model. ATO decreased cell viability with clinically achievable concentrations (8 uM) in all cell lines investigated. This was accompanied by reduced expression of E2F1, cyclin A2, skp2, c-myc, thymidine kinase and ribonucleotide reductase M1, while p-c-Jun was upregulated. Cell viability was significantly decreased with E2F1 knockdown. Treatment with ATO resulted in phosphatidylserine externalization in H23 cells and mitochondrial membrane depolarization in all cell lines, associated with truncation of Bid, downregulation of Bcl-2, upregulation of Bax and Bak, caspase-9 and caspase-3 activation and PARP cleavage. Using a H358 xenograft model, the tumor growth was suppressed in the ATO treatment group during 8 days of treatment, associated with downregulation of E2F1 and upregulation of truncated Bid and cleaved caspase-3. In conclusion, ATO has potent in vitro and in vivo activity in lung adenocarcinoma, partially mediated through E2F1 downregulation and apoptosis.published_or_final_versio

    Growth suppressive effect of pegylated arginase in malignant pleural mesothelioma xenografts

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    BACKGROUND: Malignant pleural mesothelioma (MPM) is a difficult-to-treat global disease. Pegylated arginase (BCT-100) has recently shown anti-tumor effects in hepatocellular carcinoma, acute myeloid leukemia and melanoma. This study aims to investigate the effects of PEG-BCT-100 in MPM. METHODS: A panel of 5 mesothelioma cell lines (H28, 211H, H226, H2052 and H2452) was used to study the in vitro effects of BCT-100 by crystal violet staining. The in vivo effects of BCT-100 were studied using 211H and H226 nude mice xenografts. Protein expression (argininosuccinate synthetase, ornithine transcarbamylase, cleaved PARP, cleaved caspase 3, cyclins (A2, D3, E1 and H), CDK4 and Ki67) and arginine concentration were evaluated by Western blot and ELISA respectively. Cellular localization of BCT-100 was detected by immunohistochemistry and immunoflorescence. TUNEL assay was used to identify cellular apoptotic events. RESULTS: Argininosuccinate synthetase was expressed in H28, H226, and H2452 cells as well as 211H and H266 xenografts. Ornithine transcarbamylase was undetectable in all cell lines and xenograft models. BCT-100 reduced in vitro cell viability (IC50 values at 13-24 mU/ml, 72 h) across different cell lines and suppressed tumor growth in both 211H and H226 xenograft models. BCT-100 (60 mg/kg) significantly suppressed tumor growth (p < 0.01) with prolonged median survival (p < 0.01) in both xenograft models. Combining BCT-100 with pemetrexed or cisplatin conferred no additional benefits over single agents. Serum and intratumoral arginine levels were effectively decreased by BCT-100, associated with cytosolic accumulation of BCT-100 within tumor cells. Apoptosis (PARP cleavage in 211H xenografts; Bcl-2 downregulation, and cleavage of PARP and caspase 3 in H226 xenografts; positive TUNEL staining in both) and G1 arrest (downregulation of cyclin A2, D3, E1 and CDK4 in 211H xenografts; suppression of cyclin A2, E1, H and CDK4 in H226 xenografts) were evident with BCT-100 treatment. Furthermore, proliferative factor Ki67 was downregulated in BCT-100 treatments arms. CONCLUSIONS: BCT-100 suppressed tumor growth with prolonged median survival partially mediated by intratumoral arginine depletion resulting in apoptosis and G1 arrest in mesothelioma xenograft models. The findings provide scientific evidence to support further clinical development of BCT-100 in treatment of MPM.published_or_final_versio

    Dual action of arsenic trioxide on thymidylate synthase and apoptosis in mesothelioma

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    OBJECTIVE: Malignant pleural mesothelioma is a global health issue. Arsenic trioxide (ATO) has been shown to suppress thymidylate synthase (TYMS) in colorectal cancer (decrease cell growth) and induce apoptosis (cell death) in blood cancer. The effect of ATO in mesothelioma was therefore studied. MATERIALS AND METHODS: A panel of 5 mesothelioma cell lines was used to study the effect of ATO on cell viability, TYMS protein expression and TYMS activity. Alteration of apoptotic/anti-apoptotic proteins induced by ATO was explored. The effect of ATO was also studied using a mice model. RESULTS: Application of ATO demonstrated anti-cancer effects in the cell line model with clinically achievable concentrations. Downregulation of TYMS protein and TYMS activity were also observed. The expression of anti-apoptotic factors were decreased while apoptotic factors were increased so as apoptosis was induced. In mice model, the relative tumor volumes were reduced in the ATO treatment group. CONCLUSION: ATO has potent antiproliferative and cytotoxic effects in mesothelioma by TYMS downregulation and apoptosis. There is sound scientific evidence to support the clinical application of ATO in treatment of mesothelioma.目的: 惡性胸膜間皮瘤是一個全球性的健康問題。砒霜已被證明能抑制腸癌的胸苷酸合成酶(TYMS)(減慢癌細胞生長), 而且可引發血癌細胞凋亡(死亡)。因此,我們研究砒霜在間皮瘤的效果。 研究方法: 我們利用間皮瘤細胞株測試砒霜對細胞活性,TYMS蛋白表達和活性的影響,以及對凋亡相關蛋白表達的影 響。並利用老鼠模型研究砒霜的抗癌效果。 結果: 在細胞模型中應用的砒霜濃度在臨床有效濃度之內。砒霜可抑制TYMS蛋白表達及其活性。同時,通過下調抗凋 亡蛋白和上調凋亡蛋白的表達引發細胞凋亡。在老鼠模型中,砒霜治療組的腫瘤體積明顯較小。 結論:砒霜具有強效的抗癌作用。此研究提供可靠的科學證據支持砒霜治療間皮瘤的臨床應用。published_or_final_versio

    Tumour Growth-Suppressive Effect of Arsenic Trioxide in Squamous Cell Lung Carcinoma

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    Squamous cell lung carcinoma (SCC) is the second commonest subtype of non-small cell lung carcinoma. The anticancer effects of arsenic trioxide (ATO) in lung adenocarcinoma and small cell lung carcinoma have been reported while in SCC are unknown. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and Western blot were used to determine cell viability and protein expression respectively. Phosphatidylserine externalization, mitochondrial membrane depolarization and cell cycle distribution were studied using flow cytometry. The in vivo effect of ATO was investigated with a xenograft model. SK-MES-1 and SW900 SCC cells were sensitive to clinically relevant concentrations of ATO. ATO induced apoptosis, mitochondrial membrane depolarization, G2/M arrest, downregulation of XIAP, Bcl-2, E2F1, thymidylate synthase and RRM1 as well as upregulation of Bak, cleaved PARP and cleaved caspase 3 in a cell-line specific manner. In SW900 xenograft model, tumour growth was inhibited by ATO with formation of apoptotic bodies and downregulation of Bcl-2 and E2F1. In conclusion, ATO suppressed growth of SCC in vitro and in vivo.published_or_final_versio

    Retinal image enhancement via a multiscale morphological approach with OCCO filter.

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    Retinal images are widely used for diagnosis and eye disease detection. However, due to the acquisition process, retinal images often have problems such as low contrast, blurry details or artifacts. These problems may severely affect the diagnosis. Therefore, it is very impor tant to enhance the visual quality of such images. Contrast enhancement is a pre-processing applied to images to improve their visual quality. This technique betters the identification of retinal structures in degraded reti nal images. In this work, a novel algorithm based on multi-scale mathe matical morphology is presented. First, the original image is blurred us ing the Open-Close Close-Open (OCCO) filter to reduce any artifacts in the image. Next, multiple bright and dark features are extracted from the filtered image by the Top-Hat transform. Finally, the maximum bright values are added to the original image and the maximum dark values are subtracted from the original image, previously adjusted by a weight. The algorithm was tested on 397 retinal images from the public STARE database. The proposed algorithm was compared with state of the art al gorithms and results show that the proposal is more efficient in improving contrast, maintaining similarity with the original image and introducing less distortion than the other algorithms. According to ophthalmologists, the algorithm, by improving retinal images, provides greater clarity in the blood vessels of the retina and would facilitate the identification of pathologies.CONACYT - Consejo Nacional de Ciencia y TecnologíaPROCIENCI

    Correlation between endometrial dating of luteal phase days 6 and 10 of the same menstrual cycle

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    CONTEXT: Endometrial maturation, important in the diagnosis of infertile couples, has been evaluated since 1950 using the Noyes criteria. Nevertheless, there is no consensus regarding the most suitable period of the luteal phase for performing the biopsy. OBJETIVE: This study evaluated the correlation between the histological dating of two endometrial biopsies performed in the same menstrual cycle, on luteal phase days six and ten.DESIGN: Prospective study. SETTING: Human Reproduction Division of the Federal University of São Paulo, referral center. PATIENTS:Twenty-five women complaining of infertility had their menstrual cycles monitored by ultrasound and LH plasma levels, to obtain evidence of ovulation. PROCEDURES: Endometrial biopsies were performed on luteal phase days LH+6 and LH+10 (luteal phase day 1 = LH+1 = the day that follows LH peak). Dating was done according to morphometric criteria, in which an endometrium sample is considered out of phase if the minimum maturation delay is one day. On day LH+6, blood was drawn for plasma progesterone level determination. RESULTS: All patients had an ovulatory cycle (mean LH peak: 47.4 U/L; mean follicular diameter on LH peak day: 18.9 mm; mean endometrial thickness on LH peak day: 10.3 mm; mean plasma progesterone level on day LH+6: 14.4 ng/ml). 14 patients had both biopsies in phase; 5 patients had out of phase biopsies only on day LH+6; 3 had out of phase biopsies only on day LH+10 and 3 patients had out of phase biopsies on both days. McNemar's test showed no statistical difference between these data (p>33.36%). CONCLUSIONS: The correlation found between the endometrial datings suggests that biopsies performed on either of these two days are suitable for evaluation of endometrial maturation.CONTEXTO: A verificação da maturidade endometrial, elemento diagnóstico necessário na avaliação do casal com queixa de infertilidade, vem sendo feita desde 1950 através do critério de datação histológica de Noyes. No entanto, não existe um consenso em relação ao período da fase lútea mais adequado para a colheita. OBJETIVO: Avaliar a correlação entre as datações histológicas de duas amostras de endométrio colhidas nos dias 6 e 10 da fase lútea de um mesmo ciclo menstrual. LOCAL: Setor de Reprodução Humana da Universidade Federal de São Paulo (UNIFESP). TIPO DE ESTUDO: Estudo prospectivo. Constou da comparação entre duas datações de endométrio num mesmo ciclo menstrual. PARTICIPANTES: 25 pacientes com queixa de infertilidade tiveram um ciclo menstrual monitorizado por ultra-sonografia e medida plasmática de LH, para demonstração de ovulação. PROCEDIMENTO: Biópsias de endométrio foram feitas nos dias LH+6 e LH+10 da fase lútea, considerando-se o dia seguinte ao do pico de LH como LH+1. A datação foi feita de acordo com critério morfométrico, considerando-se o endométrio como fora de fase, se o atraso de maturação mínimo fosse de um dia. No dia LH+6 foi feita dosagem de progesterona plasmática. RESULTADOS: Todas as pacientes apresentaram ciclos ovulatórios (média dos valores de pico de LH: 47,3 U/L; média dos diâmetros foliculares no dia do pico de LH: 18,9 mm; média das espessuras do endométrio no dia do pico de LH: 10,3 mm; média das concentrações de progesterona plasmática no dia LH+6: 14,4 ng/ml.). Em 14 pacientes, as duas biópsias estavam em fase. Houve atraso de maturação apenas no dia LH+6 em cinco pacientes; apenas no dia LH+10 em três pacientes e, nos dois dias, em três pacientes. Não houve diferença estatística entre esses valores (teste de McNemar, p=33,36%). CONCLUSÕES: Os resultados sugerem que a colheita do endométrio em qualquer dos dias (sexto ou décimo) da fase lútea fornece resultados semelhantes em relação à maturidade endometrial.Universidade Federal de São Paulo (UNIFESP)UNIFESPSciEL

    Adrenomedullin as a biomarker for tubal ectopic pregnancy: new evidence from adrenomedullin function in the nasal ciliary epithelium

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    Oral Session 3: Female Reproductive Tract: abstract no. O019INTRODUCTION: Adrenomedullin (ADM) is a potent vasodilator belonging to the calcitonin family with a high homology to calcitonin gene-related peptide (CGRP). The combination of calcitonin receptor-like receptor and receptor activity-modifying protein (RAMP) isoforms determines the ligand selectivity for CGRP and ADM. Our laboratory previously showed that oviduct produced the greatest amount of adrenomedullin in the rat female reproductive tract. ADM was found to play a crucial role in transporting the gametes/embryos by increasing the oviductal ciliary beat and inhibiting the contraction of the rat oviduct. Similar results were also found in hum…postprin
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