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BACKGROUND@#MicroRNAs (miRNAs) are non-coding small molecule RNAs that are widely found in eukaryotic organisms, although some miRNAs have been found in tumors, the expression and effects of miR-665 on small cell lung cancer (SCLC) are unclear. The aim of this study was to analyze the effects of miR-665 on proliferation, cycle, invasion and migration of SCLC cells, and to explore the role of miR-665 in SCLC and its working mechanism.@*METHODS@#The expression of miR-665 in SCLC tissues and adjacent normal tissues was detected by qRT-PCR. TargetScan predicted potential target genes for miR-665 and validated with dual luciferase reporter assays, qRT-PCR and Western blot. CCK8 assay, flow cytometry, Transwell and wound healing assay to detect the effects of miR-665 and LLGL1 on proliferation, invasion, migration and S-phase fraction of SCLC cell line NCI-H446, NCI-H1688. A nude mouse xenograft model of SCLC was constructed and the effect of miR-665 on tumor growth in mice was observed.@*RESULTS@#The expression of miR-665 in SCLC tissues was significantly higher than that in non-tumor normal tissues. MiR-665 could target 3'-UTR of LLGL1 and inhibit its expression. Compared with non-tumor normal tissues, the expression of LLGL1 was significantly lower in SCLC tissues. Inhibition of miR-665 expression could inhibit proliferation, S-phase fraction, invasion and migration ability of SCLC NCL-H446 cells, and interference LLGL1 expression could reverse this inhibition effect. Up-regulation of miR-665 expression could promoted proliferation, S-phase fraction, invasion and migration ability of SCLC NCI-H1688 cells, but this promotion effect was also reversed by overexpression of LLGL1. In a nude mouse xenograft model of SCLC, inhibition of miR-665 expression could up-regulate LLGL1 protein expression and inhibit tumor growth, while up-regulation of miR-665 expression could produce opposite results.@*CONCLUSIONS@#The expression of miR-665 is closely related to SCLC. miR-665 can promote the biological behavior of SCLC cells by inhibiting the expression of target gene LLGL1, and miR-665 play a role in tumor-promoting genes in SCLC.
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Objective To establish the reference range of serum human serum insulin levels in our laboratory and investigate measurement stability, Methods The automated Architect i2000 chemiluminescence immunoassay, calibrator and quality control materials were used to measure concentration of serum insulin. Totally 413 cases of healthy adults were enrolled. The physiologic characteristics and the influence of laboratory markers on insulin levels were analyzed. Then the reference range in our laboratory was established. The thermal stability of insulin at different temperatures was investigated. Results Within-run imprecision and between-day imprecision of the automated Architect i2000 insulin assay were 1.67% and 2. 6%, which indicated that this system had good analytical performance. The subjects were classified into 4 groups according to age range ( 10 years). There was no significant difference among four age groups (the median is 5. 6, 5.2, 5.3 and 5. 7 mU/L) (X<'2> = 1. 929,P >0.05). However, the insulin levels were higher in female ( median = 5.7 mU/L) than male ( median = 5.0 mU/L) ( Z = 3.696, P < 0.01 ). The reference range was established based on the 2. 5 and 97.5 percentile values. The reference range of insulin for female was 2. 6-11.8 mU/L and 2. 3-11.6 mU/L for men, which differed from that of other insulin assay. Insulin had a positive correlation with BMI (r =0. 115 ,P =0. 019) and triglyeeride (r =0.143 ,P = 0. 004), and a negative correlation with high density lipoprotein (r = -0.179, P = 0.000). Insulin was stable at 25 ℃ for at least 4 hours or 4 ℃ for 24 hours or could be extended to at least 7 days when stored at -20 ℃. Conclusion Gender is an important physiologic characteristic which has an impact on human serum insuhn level. Insulin reference range should be established according to gender. Insulin immunoreactivity was not very stable at different temperatures.
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Objective To investigate the role of ghrelin promoting proliferation of pancreatic β cells and the mechanism of it. Methods Mouse pancreatic β cells(NIT-1)were treated with different concentrations of ghrelin.NIT-1 cells proliferation was measured by MTT incorporation assay,and the cell cycle was measured by Flow Cytometry,and the expression of ERK1/2 and the level of ERK1/2 phosphorylation were determined by Western blot assay.Results With the increase of concentration and the time of treatment,ghrelin promotes cell survival of pancreatic β cells.The S-phase portion was changed after treatment of ghrelin on NIT-1 for 48 hours.The S-phase percentage in the groups where ghrelin concention change from 0 tO 10-9,10-8,10-7 mol/L were(34.5±6.5)%,(42.1±7.4)%,(50.6±5.8)%,(71.4±9.4)%,respectively.Ghrelin also induces phesphorilation of ERK1/2 in NIT-1 cell,and a doseeffect relationship was demonstrated.Conclusion Ghrelin could promote proliferation of pancreatic β cells through activating the MAPK/ERK1/2 signaling pathway and changing the cell cycle.