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PURPOSE: This study has been focused on assessing the Open Science scenario of cancer research during the period 2011-2021, in terms of the derived scientific publications and raw data dissemination. METHODS: A cancer search equation was executed in the Science Citation Index-Expanded, collecting the papers signed by at least one Spanish institution. The same search strategy was performed in the Data Citation Index to describe dataset diffusion. RESULTS: 50,822 papers were recovered, 71% of which belong to first and second quartile journals. 59% of the articles were published in Open Access (OA) journals. The Open Access model and international collaboration positively conditioned the number of citations received. Among the most productive journals stood out Plos One, Cancers, and Clinical and Translational Oncology. 2693 genomics, proteomics and metabolomics datasets were retrieved, being Gene Expression Omnibus the favoured repository. CONCLUSIONS: There has been an increase in oncology publications in Open Access. Most were published in first quartile journals and received higher citations than non-Open Access articles, as well as when oncological investigation was performed between international research teams, being relevant in the context of Open Science. Genetic repositories have been the preferred for sharing oncology datasets. Further investigation of research and data sharing in oncology is needed, supported by stronger Open Science policies, to achieve better data sharing practices among three scientific main pillars: researchers, publishers, and scientific organizations.
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Pesquisa Biomédica , Disseminação de Informação , Neoplasias , Humanos , Neoplasias/genética , Oncologia , Bibliometria , Publicações Periódicas como Assunto/estatística & dados numéricos , Acesso à Informação , Espanha , Publicação de Acesso AbertoRESUMO
Model organisms are fundamental in cancer research given that they rise the possibility to characterize in a quantitative-objective fashion the organisms as a whole in ways that are infeasible in humans. From this perspective, model organisms with short generation times and established protocols for genetic manipulation allow the understanding of basic biology principles that might guide carcinogenic onset. The cancer-hallmarks (CHs) approach, a modular perspective for cancer understanding, stands that underlying the variability among different cancer types, critical events support the carcinogenic origin and progression. Thus, CHs as interconnected genetic circuitry, have a causal effect over cancer biogenesis and might represent a comparison scaffold among model organisms to identify and characterize evolutionarily conserved modules to understand cancer. Nevertheless, the identification of novel cancer regulators by comparative genomics approaches relies on selecting specific biological processes or related signaling cascades that limit the type of detected regulators, even more, holistic analysis from a systemic perspective is absent. Similarly, although the plant Arabidopsis thaliana has been used as a model organism to dissect specific disease-associated mechanisms, given the evolutionary distance between plants and humans, a general concern about the utility of using A. thaliana as a cancer model persists. In the present research, we take advantage of the CHs paradigm as a framework to establish a functional systemic comparison between plants and humans, that allowed the identification not only of specific novel key genetic regulators, but also, biological processes, metabolic systems, and genetic modules that might contribute to the neoplastic transformation. We propose five cancer-hallmarks that overlapped in conserved mechanisms and processes between Arabidopsis and human and thus, represent mechanisms which study can be prioritized in A. thaliana as an alternative model for cancer research. Additionally, derived from network analyses and machine learning strategies, a new set of potential candidate genes that might contribute to neoplastic transformation is described. These findings postulate A. thaliana as a suitable model to dissect, not all, but specific cancer properties, highlighting the importance of using alternative complementary models to understand carcinogenesis.
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LQFM018 is a novel antineoplastic prototype, showing an expressive drug-triggered K562 leukemic cells death mechanism, through necroptotic signaling. Due to its promising effect, this study aimed to evaluate the pharmacokinetics of LQFM018 in rats, using a new validated bioanalytical LC-MS/MS-based method. Chromatographic column was an ACE® C18 (100 mm × 4.6 mm, 5 µm) eluted by a mobile phase composed of ammonium acetate 2 mM and formic acid 0.025%:methanol (50:50, v/v), under flow of 1.2 mL/min and injection volume of 3.0 µL. LQFM018 was extracted from rat plasma by a simple liquid-liquid method, using MTBE solvent. Rats were administered intraperitoneally at LQFM018 100 mg/kg dose and blood samples were collect at times of 0, 1, 2, 3, 4, 5, 6, 7, 8, and 9 h. Bioanalytical-LC-MS/MS-based method was rapid, high throughput and sensitive with a good linearity ranging from 10 (LLOQ) to 15000 ng/mL, besides precise and accurate, ranging of 0.8-7.3% and 96.8-107.6%, respectively. The prototype LQFM018 was rapid and well absorbed, and highly distributed, apparently due to its high lipid solubility. These features are primordial for an anticancer agent in the treatment of deep tumors, such as bone marrow neoplasms, in which the drug might permeate easily tissue barriers. Also, LQFM018 has demonstrated a high clearance, according to a low t1/2in rats, indicating a relative fast elimination phase related to a possible intense hepatic biotransformation. These information support further studies to establish new understands on pharmacokinetics of promising antineoplastic prototype LQFM018 from preclinical and clinical evaluations.
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Antineoplásicos , Espectrometria de Massas em Tandem , Ratos , Animais , Cromatografia Líquida/métodos , Piperazina , Espectrometria de Massas em Tandem/métodos , Piperazinas , Reprodutibilidade dos TestesRESUMO
BACKGROUND: In high-income countries, hope facilitates parental coping and builds the clinical relationship between families of children with cancer and their clinicians. However, the manifestation of hope in low- and middle-income countries (LMICs) remains poorly understood. Our study explores Guatemalan parents' experiences with hope during the pediatric oncology diagnostic process and aims to identify discrete actions clinicians take to support hope. METHODS: This qualitative study utilized audio-recordings of the diagnostic process and an additional semi-structured interview for 20 families of children with cancer at Unidad Nacional de Oncología Pediátrica in Guatemala. Spanish audio-recordings were translated into English, transcribed, and coded using a priori and novel codes. Thematic content analysis using constant comparative methods explored parents' hopes and concerns. RESULTS: At diagnosis, Guatemalan parents expressed both hopes and concerns related to the entire cancer continuum. Throughout the diagnostic process, hope grew as concerns were alleviated. Clinicians supported hope by creating a supportive environment, providing information, affirming religious beliefs, and empowering parents. These strategies helped parents shift their focus from fear and uncertainty toward hope for their child's future. Parents expressed that establishing hope improved mood, promoted acceptance, and enabled them to care for themselves and their children. CONCLUSION: These results confirm the relevance of supporting hope in pediatric oncology settings in LMICs and suggest that culture informs hope-related needs. Supporting hope is critical across cultures and can be integrated into clinical conversation using the four processes identified by our results.
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Neoplasias , Pais , Humanos , Criança , Neoplasias/diagnóstico , Neoplasias/terapia , Oncologia , Comunicação , MedoRESUMO
In 2013, recognizing that Colorectal Cancer (CRC) is the second leading cause of death by cancer worldwide and that it was a neglected disease increasing rapidly in Mexico, the community of researchers at the Biomedicine Research Unit of the Facultad de Estudios Superiores Iztacala from the Universidad Nacional Autónoma de México (UNAM) established an intramural consortium that involves a multidisciplinary group of researchers, technicians, and postgraduate students to contribute to the understanding of this pathology in Mexico. This article is about the work developed by the Mexican Colorectal Cancer Research Consortium (MEX-CCRC): how the Consortium was created, its members, and its short- and long-term goals. Moreover, it is a narrative of the accomplishments of this project. Finally, we reflect on possible strategies against CRC in Mexico and contrast all the data presented with another international strategy to prevent and treat CRC. We believe that the Consortium's characteristics must be maintained to initiate a national strategy, and the reported data could be useful to establish future collaborations with other countries in Latin America and the world.
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Neoplasias Colorretais , Estudantes , Humanos , México , Estudos Interdisciplinares , Terapias em Estudo , Neoplasias Colorretais/diagnóstico , Neoplasias Colorretais/terapiaRESUMO
Despite the developments in cancer research over years, cancer is still one of the leading causes of death worldwide. In Brazil, the number of cancer cases for the several next years (2020-2022) is expected to increase up to 625,000. Thus, translational research has been vital to determine the potential risk, prognostic, and predictive biomarkers in cancer. Therefore, Barretos Cancer Hospital implemented a biobank (BB-BCH) in 2006, which is responsible for processing, storage, and provision of biological materials from cancer and non-cancer participants. Hence, this article aimed to describe BB-BCH's history, experiences, and outcomes and explore its impact on Brazilian translational oncology research scenario. BB-BCH has a multidisciplinary team who are responsible for guaranteeing the quality of all processes as recommended by international guidelines for biobanks. Furthermore, BB-BCH has ample equipment to ensure the quality of all material requested by researchers as genetic material (DNA and RNA) and/or entire biospecimens. From 2006 to 2019, BB-BCH contained 252,069 samples from 44,933 participants, the whole collection is represented by 15 different types of biospecimens collected from them. According to our data, the most collected and stored topography in men is head and neck (29%); in women is breast (28%); and in children is torso and limb (27%) samples. Finally, we supported national and international consortia and projects such as The Cancer Genome Atlas. BB-BCH is a vital knowledge source for scientific community, enabling the development of high-quality studies, with a wide variety of tumor categories and high national representativeness of Brazilian population.
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Pesquisa Biomédica , Neoplasias , Bancos de Espécimes Biológicos , Biomarcadores , Institutos de Câncer , Criança , Feminino , Humanos , Masculino , RNA , Pesquisa Translacional BiomédicaRESUMO
Glutamine metabolism is one of the hallmarks of cancers which is described as an essential role in serving as a major energy and building blocks supply to cell proliferation in cancer cells. Many malignant tumor cells always display glutamine addiction. The "kidney-type" glutaminase (GLS1) is a metabolism enzyme which plays a significant part in glutaminolysis. Interestingly, GLS1 is often overexpressed in highly proliferative cancer cells to fulfill enhanced glutamine demand. So far, GLS1 has been proved to be a significant target during the carcinogenesis process, and emerging evidence reveals that its inhibitors could provide a benefit strategy for cancer therapy. Herein, we summarize the prognostic value of GLS1 in multiple cancer type and its related regulatory factors which are associated with antitumor activity. Moreover, this review article highlights the remarkable reform of discovery and development for GLS1 inhibitors. On the basis of case studies, our perspectives for targeting GLS1 and development of GLS1 antagonist are discussed in the final part.
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Glutaminase/antagonistas & inibidores , Glutaminase/metabolismo , Glutamina/metabolismo , Proteínas de Neoplasias/metabolismo , Neoplasias/metabolismo , Neoplasias/patologia , Apoptose/fisiologia , Benzofenantridinas/farmacologia , Proliferação de Células/fisiologia , Diazo-Oxo-Norleucina/metabolismo , Progressão da Doença , Resistencia a Medicamentos Antineoplásicos , Genes myc/fisiologia , Humanos , MicroRNAs/fisiologia , NF-kappa B/metabolismo , Proteínas de Neoplasias/antagonistas & inibidores , Neoplasias/tratamento farmacológico , Neoplasias/mortalidade , Oxirredução , Fosfatos/metabolismo , Prognóstico , Proteína do Retinoblastoma/metabolismo , Sulfetos/farmacologia , Tiadiazóis/farmacologiaRESUMO
BACKGROUND: Brazil is a country of continental dimensions with great potential for the development of clinical studies across the whole territory to tackle the needs of the population. It is therefore important to obtain the national profile of clinical trials in order to identify local strengths and weaknesses in terms of productivity and study application. Thus, this paper aims to highlight the profiles of clinical studies on cancer developed and sponsored by hospitals, institutes, universities and international institutions in Brazil between 1997 and 2015. METHODS: This is a retrospective and analytical study in which the content analysis method of Laurence Bardin was used. Data were collected from the clinicaltrials.govdatabase, where 783 clinical studies on cancer prevention, diagnosis and treatment were found; 188 (24 %) of these corresponded to national initiatives and 595 (76 %) to international initiatives. RESULTS: The results show an increase in the number of national clinical studies, in particular phase III studies. There is a clear absence of national clinical studies focusing on the development of new chemical and biotechnological products in oncology. CONCLUSION: The results indicate a regional imbalance in the distribution of national and international clinical trials. POLICY SUMMARY: The present study aims to improve understanding of the profile of clinical studies registered in Brazil and to draw attention to the improvements needed in the health sector's productivity to address the national demand.
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Neoplasias , Brasil/epidemiologia , Humanos , Neoplasias/diagnóstico , Estudos RetrospectivosRESUMO
Linalool and 1,8-cineole are plant-derived isoprenoids with anticancer activities in lung cancer cells, nevertheless, the cellular and molecular mechanisms of action remain poorly understood. The purpose of this study was to determine the anticancer mechanisms of action of linalool and 1,8-cineole in lung adenocarcinoma A549 cells. Linalool (0-2.0 mM) and 1,8-cineole (0-8.0 mM) inhibited cell proliferation by inducing G0/G1 and/or G2/M cell cycle arrest without affecting cell viability of normal lung WI-38 cells. None of the two monoterpenes were able to induce apoptosis, as observed by the lack of caspase-3 and caspase-9 activation, PARP cleavage, and DNA fragmentation. Linalool, but not 1,8-cineole, increased reactive oxygen species production and mitochondrial membrane potential depolarization. Reactive oxygen species were involved in cell growth inhibition and mitochondrial depolarization induced by linalool since the antioxidant N-acetyl-L-cysteine prevented both effects. Besides, linalool (2.0 mM) and 1,8-cineole (8.0 mM) inhibited A549 cell migration. The combination of each monoterpene with simvastatin increased the G0/G1 cell cycle arrest and sensitized cells to apoptosis compared with simvastatin alone. Our results showed that both monoterpenes might be promising anticancer agents with antiproliferative, anti-metastatic, and sensitizer properties for lung cancer therapy.
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AIMS: Glioblastoma multiforme (GBM) is the most devastating malignant primary brain tumor known. Life expectance is around 15 months after diagnosis. Several events contribute to the GBM progression such as uncontrolled genetic cancer cells proliferation, angiogenesis (mostly vascular endothelial growth factor (VEGF)-mediated), tissue invasion, glioma stem cell activity, immune system failure, and a hypoxic and inflammatory tumor microenvironment. Tumor cells antiproliferative effect of 20 nm citrate-covered gold nanoparticles (cit-AuNP) has been reported, along with anti-inflammatory and anti-oxidative effects. We aimed to test whether either chronic treatment with 20 nm cit-AuNP or anti-VEGF antibody (Ig)-covered AuNP could reduce GBM progression in mice. MAIN METHODS: Effect of the gold nanoparticles on the GL261 glioblastoma cells proliferation in vitro, and on the GL261-induced glioblastoma cell growth in C57BL/6 mice in vivo were tested. Besides, fluorophore-conjugated gold nanoparticles penetration through the GL261 plasma cell membrane, gold labelling in brain parenchyma of glioblastoma-carrying mice, and VEGF expression into the tumor were evaluated. KEY FINDINGS: We observed cit-AuNP did no change the GL261 cells proliferation. Similarly, we demonstrated chronic treatment with either cit-AuNP or anti-VEGF Ig-covered AuNP did not modify the GL261 cells-induced GBM progression in mice. By the end, we showed AuNPs did not trespass in appreciable amount both the GL261 plasma cell membrane and the tumoral blood brain barrier (BBB), and did not change the VEGF expression into the tumor. SIGNIFICANCE: 20 nm cit-AuNP or anti-VEGF Ig covered-AuNP are not good tools to reduce GBM in mice, probably because they do not penetrate both tumor cells and BBB in enough amount to reduce tumor growing.
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Our previous reports showed that 1α,25-dihydroxyvitamin D3 (1α,25(OH)2D3) has antiproliferative actions in endothelial cells stably expressing viral G protein-coupled receptor (vGPCR) associated with the pathogenesis of Kaposi's sarcoma. It has been reported that COX-2 enzyme, involved in the tumorigenesis of many types of cancers, is induced by vGPCR. Therefore, we investigated whether COX-2 down-regulation is part of the growth inhibitory effects of 1α,25(OH)2D3. Proliferation was measured in presence of COX-2 inhibitor Celecoxib (10-20 µM) revealing a decreased in vGPCR cell number, displaying typically apoptotic features in a dose dependent manner similarly to 1α,25(OH)2D3. In addition, the reduced cell viability observed with 20 µM Celecoxib was enhanced in presence of 1α,25(OH)2D3. Remarkably, although COX-2 mRNA and protein levels were up-regulated after 1α,25(OH)2D3 treatment, COX-2 enzymatic activity was reduced in a VDR-dependent manner. Furthermore, an interaction between COX-2 and VDR was revealed through GST pull-down and computational analysis. Additionally, high-affinity prostanoid receptors (EP3 and EP4) were found down-regulated by 1α,25(OH)2D3. Altogether, these results suggest a down-regulation of COX-2 activity and of prostanoid receptors as part of the antineoplastic mechanism of 1α,25(OH)2D3 in endothelial cells transformed by vGPCR.
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PURPOSE: Advanced triple negative breast cancer (ATNBC) is defined by a lack of expression of hormones receptors as well as HER2/neu and its high probability of visceral metastasis. This pathology is associated with a poor prognosis. Previously, we found that T2, an N 4-arylsubstituted thiosemicarbazone (N 4-TSC), had cytotoxic effect on human breast cancer cells lines. Hence, in this study, we investigated the anti-metastasic action of T2 on ATNBC. METHODS: In order to deepen T2 action mode on ATNBC, we first confirmed T2 cytotoxicity on a panel of TNBC cells and then continued studying T2 effects in vitro an in vivo on the syngeneic 4T1 mouse model. RESULTS: We found that T2 had a cytotoxic effect comparable to chemotherapeutics used in present treatment schemes for ATNBC. T2 treatment not only induced apoptosis, but it also down-modulated 4T1 invasive and metastatic-associated capacities, such as clonogenicity, migration and metallo-proteases activity. Moreover, this agent reduced the number of 4T1 cancer stem cells. Finally, T2 treatment induced a more differentiated cell phenotype and the overexpression of the metastasis suppressor gene NDRG-1. In vivo assays showed that T2 reduced tumor burden, down modulated local tumor invasion and significantly reduced the number of lung metastases in the 4T1 advanced TNBC murine model, while the compound did not exhibit intolerable toxicity. CONCLUSION: This study provided evidence that T2 not only exerted an anti-tumor activity but it also showed anti-invasive and anti-metastatic actions on ATNBC in vivo and in vitro, suggesting that T2 could be considered as a promising therapy that deserves further analysis.
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PURPOSE: To evaluate the splenic uptake function after irradiation with high-energy X-rays. MATERIALS AND METHODS: Fourteen male Wistar rats were distributed into three groups. Group 1 (n = 6) - control, non-irradiated; Group 2 (n = 4) - animals that were irradiated and studied 24 h after irradiation; and Group 3 (n = 4) - animals that were irradiated and studied 48 h after irradiation. The animals were irradiated with 8 Gy X-rays in the abdominal region. According with the groups, after 24 or 48 h, 1 ml/kg of a 50% colloidal carbon solution was injected in the left internal jugular vein. After 40 min, the spleens were removed for histological studies. Macrophages containing carbon pigments in their cytoplasms were counted in 16 consecutive microscopic fields, and their means were considered as the uptake pattern of each animal. RESULTS: In the control groups, carbon pigments were captured by macrophages in the red and white pulps, while in the irradiated groups, the uptake in the marginal zone, around the white pulp, was enhanced. There was no disorder on the splenic parenchyma or necrosis in histological analyzes. Qualitatively rare apoptotic events were observed, with no difference between control and irradiated animals. CONCLUSION: The high-energy X-ray, used in radiotherapy, modifies the splenic clearance, enhancing the amount of marginal zone macrophages containing colloid particles. This radiation was not associated with morphological changes, nor with necrosis or apoptosis of splenic tissue.
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Over the past few years, different Computer-Aided Diagnosis (CAD) systems have been proposed to tackle skin lesion analysis. Most of these systems work only for dermoscopy images since there is a strong lack of public clinical images archive available to evaluate the aforementioned CAD systems. To fill this gap, we release a skin lesion benchmark composed of clinical images collected from smartphone devices and a set of patient clinical data containing up to 21 features. The dataset consists of 1373 patients, 1641 skin lesions, and 2298 images for six different diagnostics: three skin diseases and three skin cancers. In total, 58.4% of the skin lesions are biopsy-proven, including 100% of the skin cancers. By releasing this benchmark, we aim to support future research and the development of new tools to assist clinicians to detect skin cancer.
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Platelet-rich-plasma (PRP) is an autologous human platelet concentrate extracted from plasma. PRP has been investigated in order to be used in many fields, with emphasis on the musculoskeletal field applied to sports injuries, as well as on other medical fields such as cardiac surgery, gynecology, pediatric surgery, urology, ophthalmology and plastic surgery. Cancer treatment is another important field where PRP should be investigated; thus, it is important validating PRP preparation protocols to be used in clinical research. Many protocols should be revised since, overall, most studies do not provide necessary information to allow them to be multiplied or replicated. The current review focuses on several topics about cancer, mainly on innovative studies about PRP use as a feasible therapeutic alternative to treat bladder cancer - a field where it could play a key role. Relevant aspects such as platelets' contribution to immune regulation and the supportive role they play in innate and adaptive immune functions are also addressed. Another important topic reviewed in the current study refers to inflammatory process regulation associated with cancer and thrombosis sites, which indicated that tumor-induced platelet activation could be used as an important therapeutic target in the future. New aspects concerning nitric oxide's ability to restrain platelet adhesion and aggregation in order to slow metastasis progress in cancer patients provide an important advantage in cancer treatment. Finally, the current review has pointed out perspectives and the main concerns about, and possibilities of, PRP use in cancer treatment.
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The aqueous extract of the Argentinean native plant, Prosopis strombulifera (PsAE), presents cytotoxicity against human cancer cell lines by inducing cytostasis, necrosis and apoptosis; with diminution of clonogenic survival; without genotoxic effects nor oral animal toxicity. Until now, the chemical extract composition and its in vivo antitumoral properties remain unknown; these studies are the aim of the current work. The PsAE was characterized by chemical fingerprinting and the metabolome was identified by tandem UHPLC-PDA-HESI-Q-orbitrap® mass spectrometry. Colorectal tumors were induced by DMH administration and melanomas resulted from B16-F0 S.C. cells injection; then, animals were treated orally with PsEA. To correlate in vivo results with in vitro cytotoxicity, B16-F0 cell were cultured to determine: cell proliferation and viability by dye exclusion assays, MTT and CFSE dilution; cell cycle distribution by flow cytometry; and immunoblotting of p21cip1, PCNA, cleaved caspase 3, cleaved PARP and TUBA1A. Based on UHPLC-OT-MS and PDA analysis, twenty-six compounds were identified, including: 5 simple organic acids, 4 phenolic acids, 4 procyanidins, 11 flavonoids, and 2 oxylipins. On C57BL6 mice, PsAE significantly increases the median survival on colorectal cancer and reduces the final volume and weight of melanomas. Over cultured cells, the treatment induce over-expression of p21, cytostasis by G2/M cell cycle arrest and apoptosis; while, on in vivo melanomas, treatment up-regulates p21 and slightly decreases PCNA. In conclusion, PsAE is composed by phenolic compounds which demonstrate cytotoxic and antitumoral properties when is orally administrated. Presented results support future research of PsAE as a potential phytomedicine for cancer treatment.
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Background: Matrix metalloproteinase 12 (MMP12), a member of MMPs, can take lots of roles including extracellular matrix component degradation, viral infection, inflammation, tissue remodeling and tumorigenesis. To explore the transcriptional regulation of MMP12 gene, a sensitive luciferase reporter HEK293 cell line for endogenous MMP12 promoter was generated by CRISPR/Cas9 technology. Results: The HEK293-MMP12-T2A-luciferase-KI cell line was successfully established by CRISPR/Cas9 technology. The sequencing results indicated that one allele of the genome was proven to have a site-directed insertion of luciferase gene and another allele of the genome was confirmed to have additional 48 bp insertion in this cell line. The cell line was further demonstrated to be a sensitive reporter of the endogenous MMP12 promoter by applying transcription factors STAT3, AP-1 and SP-1 to the cell line. The reporter cell line was then screened with bioactive small molecule library, and a small molecule Tanshinone I was found to significantly inhibit the transcriptional activity of MMP12 gene in HEK293-MMP12-T2A-luciferase-KI cell line by luciferase activity assay, which was further confirmed to inhibit the expression of MMP12 mRNA in wild-type HEK293 cells. Conclusions: This novel luciferase knock-in reporter system will be helpful for investigating the transcriptional regulation of MMP12 gene and screening the drugs targeting MMP12 gene.
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Humanos , Metaloproteinase 12 da Matriz/genética , Sistemas CRISPR-Cas , Luciferases/genética , Transcrição Gênica , Comunicação Celular , Linhagem Celular , Regiões Promotoras Genéticas/genética , Técnicas de Cultura de Células , Matriz Extracelular , Técnicas de Introdução de Genes , Repetições Palindrômicas Curtas Agrupadas e Regularmente EspaçadasRESUMO
The Kaposi's sarcoma-associated herpesvirus G protein-coupled receptor (KSHV/vGPCR) is a key molecule in the pathogenesis of Kaposi's sarcoma. We have previously shown that 1α,25(OH)2D3 or its less-calcemic analog TX 527 inhibits the proliferation of endothelial cells expressing vGPCR, NF-κB activity and induces apoptosis in a VDR dependent manner. In this work, we further explored whether 1α,25(OH)2D3 or TX 527 regulates PI3K/Akt/mTOR axis and induces autophagy as part of its antineoplastic mechanism of action. Proliferation assays indicated that vGPCR cell number decreased in presence of LY294002 (PI3K/Akt inhibitor) likewise 1α,25(OH)2D3 or TX 527 (10 nM, 48 h). Also, Akt phosphorylation was found decreased in dose (0.1-100 nM) and time response studies (12-72 h) after both compounds treatments. In addition, decreased phosphorylated Akt was significantly observed in the nucleus. Moreover, regulation of Akt phosphorylation was NF-κB and VDR dependent. TNFAIP3/A20, an ubiquitin-editing enzyme, a direct NF-κB target gene and a negative regulator of Beclin-1, was down-regulated whereas Beclin-1 was up-regulated after 10 nM of 1α,25(OH)2D3 or TX 527 treatment. Decrement in Akt phosphorylation was accompanied by a reduced mTOR phosphorylation and an increase in the autophagy marker LC3-II. Since increment in autophagosomes not always indicates increment in autophagy activity, we used Chloroquine (CQ, 1 µM), an inhibitor of autophagy flow, to confirm autophagy after both VDR agonists treatment. In conclusion, VDR agonists, 1α,25(OH)2D3 or TX 527, inhibited PI3K/Akt/mTOR axis and induced autophagy in endothelial cells expressing vGPCR by a VDR-dependent mechanism.