***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Purpose To investigate the potential c and i date microRNA ( miRNA ) biomarkers for the clinical diagnosis , classification , and prognosis of gastric cancer ( GC ) . Methods We use bioinformatics overlapping subclasses analysis to find the tumor grade and lymphatic metastasis-related GC specific miRNAs from the Cancer Genome Atlas ( TCGA ) data base . Then , we further investigated these GC specific miRNAs distributions in different GC clinical features and their correlations overall survival on the basis of GC patients ’ information and their related RNA sequencing profile from TCGA . Finally , we r and omly selected some of key miRNAs use qRT-PCR to confirm the reliability and validity . Results 22 GC specific key miRNAs were identified ( Fold-change > 2 , P < 0.05 ) , 11 of them were discriminatively expressed with tumor size , grade , TNM stage and lymphatic metastasis ( P < 0.05 ) . In addition , nine miRNAs ( miR-196b-5p , miR-135b-5p , miR-183 - 5p , miR-182 - 5p , miR-133a-3p , miR-486 - 5p , miR-144 - 5p , miR-129 - 5p and miR-145 - 5p ) were found to be significantly associated with overall survival ( log-rank P < 0.05 ) . Finally , four key miRNAs ( miR-183 - 5p , miR-486 - 5p , miR-30c-2 - 3p and miR-133a-3p ) were r and omly selected to validation and their expression levels in 53 newly diagnosed GC patients by qRT-PCR . Results showed that the fold-changes between TCGA and qRT-PCR were 100 % in agreement . We also found miR-183 - 5p and miR-486 - 5p were significantly correlated with tumor TNM stage ( P < 0.05 ) , and miR-30c-2 - 3p and miR-133a-3p were associated with tumor differentiation degree and lymph-node metastasis ( P < 0.05 ) . These verified miRNAs clinical ly relevant , and the bioinformatics analysis results were almost the same . Conclusion These key miRNAs may functions as potential c and i date biomarkers for the clinical diagnosis , classification and prognosis for GC Background MicroRNAs are aberrantly expressed and correlate with tumourigenesis and the progression of solid tumours . The miR-200 family determines the epithelial phenotype of cancer cells and regulates invasiveness and migration . Thus , we hypothesised that the quantitative detection of the miR-200 family as epithelial-specific microRNAs in the blood could be a useful clinical biomarker for gastric cancer ( GC ) . Methods We initially vali date d the expression levels of miR-200a , 200b , 200c and 141 in GC cell lines ( n = 2 ) and blood from healthy controls ( n = 19 ) using  real-time quantitative reverse transcription PCR ( qRT-PCR ) . The microarray expression profiles of the miR-200 family in 160 paired sample s of non-tumour gastric mucosae and GC were downloaded through ArrayExpress and analysed . MiR-200c was selected for clinical validation . The qRT-PCR prospect i ve assessment of miR-200c was performed using 67 blood sample s ( 52 stage I-IV GC patients and 15 controls ) ; the area under the receiver operating characteristic curve ( AUC-ROC ) was estimated . The Kaplan-Meier and Breslow-Wilcoxon tests were used to assess the correlation of miR-200c with overall and progression-free survival ( OS and PFS ) . Multivariate analyses were performed using the Cox model . Results The miR-200c blood expression levels in GC patients were significantly higher than in normal controls ( p = 0.018 ) . The AUC-ROC was 0.715 ( p = 0.012 ) . The sensitivity , specificity and accuracy rates of 65.4 % , 100 % and 73.1 % , respectively , were observed . The levels of miR-200c in the blood above the cutoff defined by the ROC curve was found in 17.6 % of stage I-II GC patients , 20.6 % of stage III patients and 67.7 % of stage IV patients ( p < 0.001 ) . The miR-200c expression levels were not associated with clinical or pathological characteristics or recent surgical procedures . There was a correlation ( p = 0.016 ) with the number of lymph node metastases and the increased expression levels of miR-200c in blood were significantly associated with a poor OS ( median OS , 9 vs 24 months ; p = 0.016 ) and PFS ( median PFS , 4 vs 11 months ; p = 0.044 ) . Multivariate analyses confirmed that the upregulation of miR-200c in the blood was associated with OS ( HR = 2.24 ; p = 0.028 ) and PFS ( HR = 2.27 ; p = 0.028 ) , independent of clinical covariates . Conclusions These data suggest that increased miR-200c levels are detected in the blood of gastric cancer patients . MiR-200c has the potential to be a predictor of progression and survival The occurrence of lymph node metastases ( LNM ) after endoscopic submucosal dissection ( ESD ) in patients with gastric cancer ( GC ) leads to poor prognosis . However , few biomarkers are available to predict LNM in GC patients . Thus , we measured expression of 6 cancer-related miRNAs using real-time RT-PCR in 102 GC sample s that were r and omized into a training set and a testing set ( each , 51 cases ) . Using logistic regression , we identified 4-miRNA ( miR-27b , miR-128 , miR-100 and miR-214 ) signatures for predicting LNM in GC patients . Patients with high-risk scores for the 4-miRNA signature tended to have higher LNM than those with low-risk scores . Meanwhile , the ROC curve of the 4-miRNA signature was better for predicting LNM in GC patients . In addition , Cox regression analysis indicated that a 2-miRNA signature ( miR-27b and miR-214 ) or a miR-214/N stage signature was predictive of survival for GC patients . This work describes a previously unrecognized 4-miRNA signature involved in LNM and a 2-miRNA signature or miR-214/N stage signature related to GC patients ’ survival 
    Output:
    
In summary , miR-20b , 21 , 106b , 125a , 137 , 141 , 145 , 146a , 196a , 196b , 206 , 214 , 218 , 451 , 486 - 5p and 506 demonstrate significantly prognostic value .
Among them , miR-20b , 125a , 137 , 141 , 146a , 196a , 206 , 218 , 486 - 5p and 506 are strong biomarkers of prognosis in GC