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The cancer syndrome polymerase proofreading-associated polyposis results from germline mutations in the POLE and POLD1 genes. Mutations in the exonuclease domain of these genes are associated with hyper- and ultra-mutated tumors with a predominance of base substitutions resulting from faulty proofreading during DNA replication. When a new variant is identified by gene testing of POLE and POLD1, it is important to verify whether the variant is associated with PPAP or not, to guide genetic counseling of mutation carriers. In 2015, we reported the likely pathogenic (class 4) germline POLE c.1373A > T p.(Tyr458Phe) variant and we have now characterized this variant to verify that it is a class 5 pathogenic variant. For this purpose, we investigated (1) mutator phenotype in tumors from two carriers, (2) mutation frequency in cell-based mutagenesis assays, and (3) structural consequences based on protein modeling. Whole-exome sequencing of two tumors identified an ultra-mutator phenotype with a predominance of base substitutions, the majority of which are C > T. A SupF mutagenesis assay revealed increased mutation frequency in cells overexpressing the variant of interest as well as in isogenic cells encoding the variant. Moreover, exonuclease repair yeast-based assay supported defect in proofreading activity. Lastly, we present a homology model of human POLE to demonstrate structural consequences leading to pathogenic impact of the p.(Tyr458Phe) mutation. The three lines of evidence, taken together with updated co-segregation and previously published data, allow the germline variant POLE c.1373A > T p.(Tyr458Phe) to be reclassified as a class 5 variant. That means the variant is associated with PPAP.
Assuntos
DNA Polimerase II , Neoplasias , Humanos , DNA Polimerase II/genética , DNA Polimerase II/química , DNA Polimerase II/metabolismo , Proteínas de Ligação a Poli-ADP-Ribose/genética , Neoplasias/genética , Mutação , Exonucleases/genética , Exonucleases/metabolismoRESUMO
The work presented in this research communication was carried out to prepare low calorie synbiotic milk beverage by optimizing water and sugar level and to investigate the effect on its storage ability of different packaging materials (polypropylene, high impact polystyrene, high-density polyethylene and glass). Addition of both water and sugar significantly (P < 0.05) affected the viscosity, probiotic count and sensory properties. Based on the findings, 40% water and 8% sugar level were optimized for the preparation of the beverage. Apparent viscosity and acidity increased whilst pH and probiotic counts declined during storage, irrespective of packaging materials. The prepared beverage remained most acceptable at refrigeration temperature up to a period of 15 and 12 d when packaged in glass and high impact polystyrene, respectively. Furthermore, it retained a minimum recommended level of probiotic (7 log cfu/ml) during storage for 15 d at 4 °C.
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Tumor cells undergoing epithelial-mesenchymal transition (EMT) lose cell surface adhesion molecules and gain invasive and metastatic properties. EMT is a plastic process and tumor cells may shift between different epithelial-mesenchymal states during metastasis. However, how this is regulated is not fully understood. Syndecan-1 (SDC1) is the major cell surface proteoglycan in epithelial cells and has been shown to regulate carcinoma progression and EMT. Recently, it was discovered that SDC1 translocates into the cell nucleus in certain tumor cells. Nuclear SDC1 inhibits cell proliferation, but whether nuclear SDC1 contributes to the regulation of EMT is not clear. Here, we report that loss of nuclear SDC1 is associated with cellular elongation and an E-cadherin-to-N-cadherin switch during TGF-ß1-induced EMT in human A549 lung adenocarcinoma cells. Further studies showed that nuclear translocation of SDC1 contributed to the repression of mesenchymal and invasive properties of human B6FS fibrosarcoma cells. The results demonstrate that nuclear translocation contributes to the capacity of SDC1 to regulate epithelial-mesenchymal plasticity in human tumor cells and opens up to mechanistic studies to elucidate the mechanisms involved.
RESUMO
Syndecan-1 (SDC1) is a cell surface heparan sulfate proteoglycan (HSPG), which regulates various signaling pathways controlling the proliferation and migration of malignant mesothelioma and other types of cancer. We have previously shown that SDC1 can translocate to the nucleus in mesothelioma cells through a tubulin-dependent transport mechanism. However, the role of nuclear SDC1 is largely unknown. Here, we performed co-immunoprecipitation (Co-IP) of SDC1 in a mesothelioma cell line to identify SDC1 interacting proteins. The precipitates contained a large number of proteins, indicating the recovery of protein networks. Proteomic analysis with a focus on nuclear proteins revealed an association with pathways related to cell proliferation and RNA synthesis, splicing and transport. In support of this, the top RNA splicing candidates were verified to interact with SDC1 by Co-IP and subsequent Western blot analysis. Further loss- and gain-of-function experiments showed that SDC1 influences RNA levels in mesothelioma cells. The results identify a proteomic map of SDC1 nuclear interactors in a mesothelioma cell line and suggest a previously unknown role for SDC1 in RNA biogenesis. The results should serve as a fundament for further studies to discover the role of nuclear SDC1 in normal and cancer cells of different origin.
Assuntos
Núcleo Celular/metabolismo , Mesotelioma/metabolismo , Proteômica/métodos , Sindecana-1/metabolismo , Linhagem Celular , Núcleo Celular/genética , Proliferação de Células , Mutação com Ganho de Função , Regulação Neoplásica da Expressão Gênica , Humanos , Mutação com Perda de Função , Mesotelioma/genética , Mapas de Interação de Proteínas , Splicing de RNA , Sindecana-1/genéticaRESUMO
Oral health influences general well-being and quality of life. Oral diseases can be debilitating and are a major heath concern worldwide. Medicinal plants have been used for thousands of years for treating human diseases. Considering the emergence of multi-drug resistant pathogens and financial difficulties in developing countries, there is an urgent need for developing new antimicrobial compounds which are safe, efficient and cost effective. Liquorice also known as yashtimadhu, sweetwood or mulhatti is one such herbal remedy which has shown to have immense potential in treatment of orofacial diseases. Liquorice is rich in secondary metabolites which are used in cosmetics, foods, traditional and modern medicine. It has well known properties such as antiviral, glucocorticoid, anti-inflammatory, antioxidant, anti-ulcerative, anti-carcinogenic and many more. Liquorice extracts and liquorice bioactive ingredients such as glabridin, licoricidin, licorisoflavan A, licochalcone A, and glycyrrhizin have shown beneficial effects in preventing and treating oral diseases. This paper reviews the effects of liquorice and its constituents on oral diseases such as dental caries, periodontitis, gingivitis, candidiasis, recurrent aphthous ulcer and oral cancer and its use as a root canal medicament and summarizes the results of clinical trials that investigated the potential beneficial effects of liquorice and its constituents as a prevention and treatment modality in oral diseases. Clinical trials, case reports and review of literature evaluating the effect of liquorice on oral microorganisms and oral diseases are included. Literature pertaining to the effects of liquorice on systemic diseases have been excluded from this review of literature.
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RNA silencing is an integral part of the cellular defense mechanisms in plants that act against virus infection. However, the specific role of RNA silencing and the interplay between host and virus components during recovery from geminivirus infection remains unknown. Hence, in this study we aimed to examine the mechanism behind the host-specific recovery of Nicotiana tabacum infected with Tomato leaf curl Gujarat virus (ToLCGV). Unlike Tomato leaf curl New Delhi virus (ToLCNDV), ToLCGV infection resulted in symptom remission in N. tabacum, and we found that this was mainly due to cross-talk between the pre-coat protein (encoded by the AV2 ORF) of the virus and the host RNA-silencing component RNA-dependent RNA polymerase 1 (encoded by NtRDR1) of N. tabacum. Moreover, apart from the AV2 mutant, other mutants of ToLCNDV developed severe symptoms on a transgenic NtRDR1-overexpression line of N. benthamiana. In contrast, inoculation with ToLCGV resulted in symptom remission, which was due to enhanced methylation of the ToLCGV promoter. Our study reveals a novel 'arms race' in which the pre-coat protein of ToLCNDV selectively blocks the recovery process through inhibiting host-specific RDR1-mediated antiviral silencing in tobacco.
Assuntos
Proteínas do Capsídeo/metabolismo , Geminiviridae/metabolismo , Nicotiana/enzimologia , Doenças das Plantas/virologia , Proteínas de Plantas/metabolismo , RNA Polimerase Dependente de RNA/metabolismo , Begomovirus/fisiologia , Proteínas do Capsídeo/genética , Geminiviridae/genética , Interações Hospedeiro-Patógeno , Doenças das Plantas/genética , Proteínas de Plantas/genética , Interferência de RNA , RNA Polimerase Dependente de RNA/genética , Nicotiana/genética , Nicotiana/virologiaRESUMO
BACKGROUND: The cell-surface heparan sulfate proteoglycan syndecan-1 is important for tumor cell proliferation, migration, and cell cycle regulation in a broad spectrum of malignancies. Syndecan-1, however, also translocates to the cell nucleus, where it might regulate various molecular functions. RESULTS: We used a fibrosarcoma model to dissect the functions of syndecan-1 related to the nucleus and separate them from functions related to the cell-surface. Nuclear translocation of syndecan-1 hampered the proliferation of fibrosarcoma cells compared to the mutant lacking nuclear localization signal. The growth inhibitory effect of nuclear syndecan-1 was accompanied by significant accumulation of cells in the G0/G1 phase, which indicated a possible G1/S phase arrest. We implemented multiple, unsupervised global transcriptome and proteome profiling approaches and combined them with functional assays to disclose the molecular mechanisms that governed nuclear translocation and its related functions. We identified genes and pathways related to the nuclear compartment with network enrichment analysis of the transcriptome and proteome. The TGF-ß pathway was activated by nuclear syndecan-1, and three genes were significantly altered with the deletion of nuclear localization signal: EGR-1 (early growth response 1), NEK11 (never-in-mitosis gene a-related kinase 11), and DOCK8 (dedicator of cytokinesis 8). These candidate genes were coupled to growth and cell-cycle regulation. Nuclear translocation of syndecan-1 influenced the activity of several other transcription factors, including E2F, NFκß, and OCT-1. The transcripts and proteins affected by syndecan-1 showed a striking overlap in their corresponding biological processes. These processes were dominated by protein phosphorylation and post-translation modifications, indicative of alterations in intracellular signaling. In addition, we identified molecules involved in the known functions of syndecan-1, including extracellular matrix organization and transmembrane transport. CONCLUSION: Collectively, abrogation of nuclear translocation of syndecan-1 resulted in a set of changes clustering in distinct patterns, which highlighted the functional importance of nuclear syndecan-1 in hampering cell proliferation and the cell cycle. This study emphasizes the importance of the localization of syndecan-1 when considering its effects on tumor cell fate.
Assuntos
Ciclo Celular/genética , Núcleo Celular/metabolismo , Redes Reguladoras de Genes , Sinais de Localização Nuclear/genética , Transdução de Sinais , Sindecana-1/metabolismo , Apoptose , Linhagem Celular Tumoral , Proliferação de Células/genética , Fibrossarcoma/genética , Fibrossarcoma/fisiopatologia , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Redes Reguladoras de Genes/genética , Redes Reguladoras de Genes/fisiologia , Humanos , Sinais de Localização Nuclear/metabolismo , Fosforilação , Processamento de Proteína Pós-Traducional , Transporte Proteico/fisiologia , Proteoma , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismoRESUMO
INTRODUCTION: Oral tori and exostosis are non-pathological bony protuberances seen on the alveolar surfaces of the jaw bones. These are commonly seen on the palatal surfaces of the maxilla [torus palatinus (TP)] and around the premolars in the lingual surface of the mandible [torus mandibularis (TM)]. The aim of this cross-sectional study was to determine the prevalence of tori/exostosis in the Malaysian population. METHODOLOGY: A total of 2666 patients were examined for the presence of tori and exostosis in the maxilla and mandible and were categorized into TP, TM, and exostosis (facial/labial). Collected data was analysed for obtaining descriptive statistics. RESULTS: 882 subjects were noticed with oral tori/exostosis among the population studied with a prevalence rate of 33%. TP was seen more in females (35%), compared to males (20%), and this difference was statistically significant (p value < 0.001). Highest prevalence of TP was seen in Malays (43%), followed by Chinese (31%) and Indians (21%), which was statistically significant (p value < 0.00). DISCUSSION: High prevalence of tori and exostosis was seen in the population studied. Though harmless, in certain circumstances, their presence necessitates changes in the denture design during fabrication of prosthesis, which the dentist should be mindful.