[miR-18a enhances the radiosensitivity of nasopharyngeal carcinoma cells through inducing autophagy].

Objective: To explore the impacts of miR-18a overexpression or depression on the radiosensitivities of nasopharyngeal carcinoma cell line CNE1 and CNE2 and underlying mechanisms. Methods: CNE1 and CNE2 were transfected with miR-18a mimics, inhibitor and the corresponding control vectors. qRT-PCR and western blot were used to determine the ataxia telangiectasia mutated (ATM) expressions in CNE1 and CNE2. CNE1 and CNE2 with stably expressing miR-18a and miR-18a siRNA were constructed. Methyl thiazolyl tetrazolium (MTT) assay was used to detect the impacts of the miR-18a overexpression or depression combined with irradiation on the cell growth. Flow cytometry was used to detect the cell apoptosis and cell cycle. Colony formation assay was used to evaluate the raodiosensitivities of cells. Acridine orange (AO) staining and western blot were used respectively to test the autophagy and the expressions of related proteins. Independent samples t test was used to compare the mean value between groups by using SPSS 16.0. Results: ATM mRNA was decreased significantly in CNE1 and CNE2 cells transfected with 100 or 200 nmol/L miR-18a mimics for 48 hours (CNE1: RQ=0.174±0.139 and 0.003±0.001, t=9.939 and 19 470.783;CNE2: RQ=0.024±0.008 and 0.019±0.012, t=270.230 and 137.746, respectively, all P<0.001). ATM proteins were also decreased after transfected with 100 or 200 nmol/L miR-18a mimics for 72 hours. While in the cells transfected with 100 and 200 nmol/L miR-18a inhibitor for 48 hours, the expressions of ATM mRNA were upregulated significantly (CNE1: RQ=9.419±2.495 and 2.500±1.063, t=-4.427 and -41.241; CNE2: RQ=7.210±0.171 and 115.875±15.805, t=-62.789 and -12.589, all P<0.05), and the expressions of ATM proteins increased after transfected for 72 hours. The growth of cells with miR-18a overexpression plus 4 Gy irradiation were obviously inhibited compared to that of cells with the 4Gy irradiation alone; while the growth of miR-18a-inhibited cells increased compared to that of cells with 4 Gy irradiation alone (all P<0.05). CNE1 transfected with 100 nmol/L miR-18a mimics plus 4 Gy irradiation showed the higher apoptosis rate than the cells with 4 Gy irradiation alone ((22.9±2.1)% vs. (16.3±1.0)%, t=-4.870, P<0.01). Compared to the cells with 4 Gy irradiation alone, miR-18a-overexpressed cells plus 4 Gy irradiation decreased their percentages in G1 phases ((20.2±3.0)% vs. (29.8±4.4)%, t=3.119) and G2/M phases ((21.5±0.9)% vs. (33.4±3.1)%, t=6.410, P<0.05 for both), and increased their percentages in S phases ((56.7±4.9)% vs. (36.8±6.4)%, t=-4.246, P<0.05), and these cells possessed less colony number after exposure to different doses of irradiation, more autophagy-lysosome number, and more expressions of LC3 proteins (all P<0.05). There were no significant differences in the expressions of p62 expressions between different groups of cells. Conclusion: Overexpression of miR-18a can enhance the radiosensitivities of NPC cells by targeting ATM to abrogate G1/S, G2/M arrest and to induce autophagy and apoptosis.

[Clinical characteristics of elderly and younger onset rheumatoid arthritis].

Objective: To compare the clinical and laboratory characteristics and therapy methods of elderly onset rheumatoid arthritis (EORA) and younger onset rheumatoid arthritis (YORA). Methods: The clinical, laboratory and therapeutic data of 481 RA patients in the Department of Rheumatology and Immunology in Peking University Third Hospital from January 2013 to December 2018 were collected and used to analyze the difference of characteristics between EORA group and YORA group, which might be useful for better diagnosis and treatment of EORA patients. Quantitative data of normal distribution were compared with t test between the two groups. Results: There were 481 patients in this cohort, of which 137(28.5%) were EORA, 344(71.5%) were YORA, with a mean age of (59±14) years (19-87 years). There were 358 females (74.4%) and 123 males (25.6%). The percentage of male patients was obviously higher in EORA group (36.5% vs 21.2%, χ(2)=12.012, P<0.01), and the average disease course was obviously shorter (Z=-7.985, P<0.01). Disease Activity Score 28 (DAS28) score was higher in EORA group (5.6±1.3 vs 5.2±1.6, t=2.549, P<0.05), meanwhile the incidences of pleural effusion and interstitial lung disease (ILD) were higher (6.6% vs 1.7%, 29.9% vs 18.3%, respectively; χ(2)=7.550, 7.797, both P<0.05). The incidences of venous thrombosis, primary hypertension, diabetes mellitus, cerebrovascular disease, coronary heart disease (CHD), peripheral atherosclerosis and cataract in EORA group were all significantly higher than those in YORA group (all P<0.05). Erythrocyte sedimentation rate (ESR) and D-Dimer in EORA group were all remarkably higher (both P<0.05). The rate of using glucocorticoid in EORA group was higher but the rate of using methotrexate and anti-tumor necrosis factor-α agents were lower (χ(2)=5.271, 8.407, 9.356, all P<0.05). Conclusion: Compared to YORA group, the percentage of male patients and disease activity of EORA group are higher. The occurrence of pleural effusion, ILD, venous thrombosis, primary hypertension, diabetes mellitus, cerebrovascular disease, CHD, peripheral atherosclerosis and cataract in EORA group are higher than those in YORA group.