Background:Oral cancer,a malignancy that is prevalent worldwide,is often diagnosed at an advanced stage.MicroRNAs(miRNAs)in circulating exosomes have emerged as promising cancer biomarkers.The role of miRNA let-7c-5p ...Background:Oral cancer,a malignancy that is prevalent worldwide,is often diagnosed at an advanced stage.MicroRNAs(miRNAs)in circulating exosomes have emerged as promising cancer biomarkers.The role of miRNA let-7c-5p in oral cancer remains underexplored,and its potential involvement in tumorigenesis warrants comprehensive investigation.Methods:Serum samples from 30 patients with oral cancer and 20 healthy controls were used to isolate exosomes and quantify their RNA content.Isolation of the exosomes was confirmed through transmission electron microscopy.Quantitative PCR was used to assess the miRNA profiles.The effects of let-7c-5p and TAGLN overexpression on oral cancer cell viability,migration,and invasion were analyzed via CCK-8 and Transwell assays.Moreover,we conducted mRNA sequencing of exosomal RNA from exosomes overexpressing let-7c-5p to delineate the gene expression profile and identify potential let-7c-5p target genes.Results:let-7c-5p was upregulated in serumderived exosomes of patients with oral cancer.Overexpression of let-7c-5p in the TCA8113 and CAL-27 cell lines enhanced their proliferative,migratory,and invasive capacities,and overexpression of let-7c-5p cell-derived exosomes promoted oral cancer cell invasiveness.Exosomal mRNA sequencing revealed 2,551 differentially expressed genes between control cell-derived exosomes and overexpressed let-7c-5p cell-derived exosomes.We further identified TAGLN as a direct target of let-7c-5p,which has been implicated in modulating the oncogenic potential of oral cancer cells.Overexpression of TAGLN reverses the promoting role of let-7c-5p on oral cancer cells.Conclusion:Our findings highlight the role of exosomal let-7c-5p in enhancing oral cancer cell aggressiveness by downregulating TAGLN expression,highlighting its potential as a diagnostic and therapeutic strategy.展开更多
C-276 nickel-based alloy is a difficult-to-cut material. In high-speed machining of Hastelloy C-276, notching is a prominent failure mode due to high mechanical properties of work piece, which results in the short too...C-276 nickel-based alloy is a difficult-to-cut material. In high-speed machining of Hastelloy C-276, notching is a prominent failure mode due to high mechanical properties of work piece, which results in the short tool life and low productivity. In this paper, a newly developed Ti（C7N3）-based cermet insert manufactured by a hot-pressing method is used to machine the C-276 nickel-based alloy, and its cutting performances are studied. Based on orthogonal experiment method, the influence of cutting parameters on tool life, material removal rates and surface roughness are investigated. Experimental research results indicate that the optimal cutting condition is a cutting speed of 50 m/min, depth of cut of 0.4 mm and feed rate of 0.15 mm/r if the tool life and material removal rates are considered comprehensively. In this case, the tool life is 32 min and material removal rates are 3000 mm^3/min, which is appropriate to the rough machining. If the tool life and surface roughness are considered, the better cutting condition is a cutting speed of 75 m/min, depth of cut of 0.6 mm and feed rate of 0.1 mm/r. In this case, the surface roughness is 0.59μm. Notch wear, flank wear, chipping at the tool nose, built-up edge（BUE） and micro-cracks are found when Ti（C7N3）-based cermet insert turned Hastelloy C-276. Oxidation, adhesive, abrasive and diffusion are the wear mechanisms, which can be investigated by the observations of scanning electron microscope and energy-dispersive spectroscopy. This research will help to guide studies on the evaluation of machining parameters to further advance the productivity of nickel based alloy Hastelloy C-276 machining.展开更多
文摘Background:Oral cancer,a malignancy that is prevalent worldwide,is often diagnosed at an advanced stage.MicroRNAs(miRNAs)in circulating exosomes have emerged as promising cancer biomarkers.The role of miRNA let-7c-5p in oral cancer remains underexplored,and its potential involvement in tumorigenesis warrants comprehensive investigation.Methods:Serum samples from 30 patients with oral cancer and 20 healthy controls were used to isolate exosomes and quantify their RNA content.Isolation of the exosomes was confirmed through transmission electron microscopy.Quantitative PCR was used to assess the miRNA profiles.The effects of let-7c-5p and TAGLN overexpression on oral cancer cell viability,migration,and invasion were analyzed via CCK-8 and Transwell assays.Moreover,we conducted mRNA sequencing of exosomal RNA from exosomes overexpressing let-7c-5p to delineate the gene expression profile and identify potential let-7c-5p target genes.Results:let-7c-5p was upregulated in serumderived exosomes of patients with oral cancer.Overexpression of let-7c-5p in the TCA8113 and CAL-27 cell lines enhanced their proliferative,migratory,and invasive capacities,and overexpression of let-7c-5p cell-derived exosomes promoted oral cancer cell invasiveness.Exosomal mRNA sequencing revealed 2,551 differentially expressed genes between control cell-derived exosomes and overexpressed let-7c-5p cell-derived exosomes.We further identified TAGLN as a direct target of let-7c-5p,which has been implicated in modulating the oncogenic potential of oral cancer cells.Overexpression of TAGLN reverses the promoting role of let-7c-5p on oral cancer cells.Conclusion:Our findings highlight the role of exosomal let-7c-5p in enhancing oral cancer cell aggressiveness by downregulating TAGLN expression,highlighting its potential as a diagnostic and therapeutic strategy.
基金Supported by Program for New Century Excellent Talents in University of China(Grant No.NCET-13-0357)Shandong Provincial Natural Science Foundation of China(Grant No.ZR2014EEM026)Tai Shan Scholar Foundation of China
文摘C-276 nickel-based alloy is a difficult-to-cut material. In high-speed machining of Hastelloy C-276, notching is a prominent failure mode due to high mechanical properties of work piece, which results in the short tool life and low productivity. In this paper, a newly developed Ti（C7N3）-based cermet insert manufactured by a hot-pressing method is used to machine the C-276 nickel-based alloy, and its cutting performances are studied. Based on orthogonal experiment method, the influence of cutting parameters on tool life, material removal rates and surface roughness are investigated. Experimental research results indicate that the optimal cutting condition is a cutting speed of 50 m/min, depth of cut of 0.4 mm and feed rate of 0.15 mm/r if the tool life and material removal rates are considered comprehensively. In this case, the tool life is 32 min and material removal rates are 3000 mm^3/min, which is appropriate to the rough machining. If the tool life and surface roughness are considered, the better cutting condition is a cutting speed of 75 m/min, depth of cut of 0.6 mm and feed rate of 0.1 mm/r. In this case, the surface roughness is 0.59μm. Notch wear, flank wear, chipping at the tool nose, built-up edge（BUE） and micro-cracks are found when Ti（C7N3）-based cermet insert turned Hastelloy C-276. Oxidation, adhesive, abrasive and diffusion are the wear mechanisms, which can be investigated by the observations of scanning electron microscope and energy-dispersive spectroscopy. This research will help to guide studies on the evaluation of machining parameters to further advance the productivity of nickel based alloy Hastelloy C-276 machining.
