title: Decreased expression of miR-133a correlates with poor prognosis in colorectal cancer patients.
abstract: OBJECTIVE
  To investigate microRNA-133a (miR-133a) expression in colorectal cancer (CRC) and its relationship with tumorigenesis and disease prognosis.
  
  
  METHODS
  Quantitative real-time polymerase chain reaction was used to measure levels of miR-133a in tumor samples and adjacent non-cancerous tissues from 169 patients undergoing radical resection for CRC. The associations between miR-133a expression and patient age, sex, as well as clinicopathologic parameters, such as tumor size, differentiation, location, invasion depth, metastasis, tumor-node-metastasis (TNM) stage and overall patient survival, were analyzed by Mann-Whitney U and Kruskal-Wallis tests. The Kaplan-Meier method and Cox proportional hazards regression analyses were performed to estimate the prognostic factors for patient survival prediction.
  
  
  RESULTS
  The expression of miR-133a was significantly downregulated in CRC tissues compared with adjacent non-cancerous tissues (P < 0.05). This reduction was associated with the depth of the local invasion, poor differentiation, lymph node metastasis and advanced disease (P < 0.05). Moreover, Kaplan-Meier analysis demonstrated that patients with low miR-133a expression had poorer overall survival (OS) than those with high miR-133a expression (P < 0.001). Univariate analysis revealed statistically significant correlations between OS and miR-133a level, tumor local invasion, lymph node metastasis and TNM stage (P < 0.001). Furthermore, miR-133a levels and TNM stage were independently associated with OS (HR = 0.590, 95%CI: 0.350-0.995, P < 0.05; and HR = 6.111, 95%CI: 1.029-36.278, P < 0.05, respectively).
  
  
  CONCLUSIONS
  The downregulation of miR-133a may play an important role in the progression of CRC and can be used as an independent factor to determine CRC prognosis.
authors.affiliation: Li-Li Wang, Lu-Tao Du, Juan Li, Yi-Min Liu, Ai-Lin Qu, Yong-Mei Yang, Xin Zhang, Gui-Xi Zheng, Chuan-Xin Wang, Department of Clinical Laboratory, Qilu Hospital, Shandong University, Jinan 250012, Shandong Province, China.
authors.forename: Li-Li
authors.initials: LL
authors.lastname: Wang
authors.affiliation: Li-Li Wang, Lu-Tao Du, Juan Li, Yi-Min Liu, Ai-Lin Qu, Yong-Mei Yang, Xin Zhang, Gui-Xi Zheng, Chuan-Xin Wang, Department of Clinical Laboratory, Qilu Hospital, Shandong University, Jinan 250012, Shandong Province, China.
authors.forename: Lu-Tao
authors.initials: LT
authors.lastname: Du
authors.affiliation: Li-Li Wang, Lu-Tao Du, Juan Li, Yi-Min Liu, Ai-Lin Qu, Yong-Mei Yang, Xin Zhang, Gui-Xi Zheng, Chuan-Xin Wang, Department of Clinical Laboratory, Qilu Hospital, Shandong University, Jinan 250012, Shandong Province, China.
authors.forename: Juan
authors.initials: J
authors.lastname: Li
authors.affiliation: Li-Li Wang, Lu-Tao Du, Juan Li, Yi-Min Liu, Ai-Lin Qu, Yong-Mei Yang, Xin Zhang, Gui-Xi Zheng, Chuan-Xin Wang, Department of Clinical Laboratory, Qilu Hospital, Shandong University, Jinan 250012, Shandong Province, China.
authors.forename: Yi-Min
authors.initials: YM
authors.lastname: Liu
authors.affiliation: Li-Li Wang, Lu-Tao Du, Juan Li, Yi-Min Liu, Ai-Lin Qu, Yong-Mei Yang, Xin Zhang, Gui-Xi Zheng, Chuan-Xin Wang, Department of Clinical Laboratory, Qilu Hospital, Shandong University, Jinan 250012, Shandong Province, China.
authors.forename: Ai-Lin
authors.initials: AL
authors.lastname: Qu
authors.affiliation: Li-Li Wang, Lu-Tao Du, Juan Li, Yi-Min Liu, Ai-Lin Qu, Yong-Mei Yang, Xin Zhang, Gui-Xi Zheng, Chuan-Xin Wang, Department of Clinical Laboratory, Qilu Hospital, Shandong University, Jinan 250012, Shandong Province, China.
authors.forename: Yong-Mei
authors.initials: YM
authors.lastname: Yang
authors.affiliation: Li-Li Wang, Lu-Tao Du, Juan Li, Yi-Min Liu, Ai-Lin Qu, Yong-Mei Yang, Xin Zhang, Gui-Xi Zheng, Chuan-Xin Wang, Department of Clinical Laboratory, Qilu Hospital, Shandong University, Jinan 250012, Shandong Province, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Li-Li Wang, Lu-Tao Du, Juan Li, Yi-Min Liu, Ai-Lin Qu, Yong-Mei Yang, Xin Zhang, Gui-Xi Zheng, Chuan-Xin Wang, Department of Clinical Laboratory, Qilu Hospital, Shandong University, Jinan 250012, Shandong Province, China.
authors.forename: Gui-Xi
authors.initials: GX
authors.lastname: Zheng
authors.affiliation: Li-Li Wang, Lu-Tao Du, Juan Li, Yi-Min Liu, Ai-Lin Qu, Yong-Mei Yang, Xin Zhang, Gui-Xi Zheng, Chuan-Xin Wang, Department of Clinical Laboratory, Qilu Hospital, Shandong University, Jinan 250012, Shandong Province, China.
authors.forename: Chuan-Xin
authors.initials: CX
authors.lastname: Wang
mesh_terms: D014408:Biomarkers, Tumor / Q000235:genetics*; D002454:Cell Differentiation; D015179:Colorectal Neoplasms / Q000235:genetics* / Q000401:mortality / Q000473:pathology / Q000601:surgery; D015536:Down-Regulation; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D053208:Kaplan-Meier Estimate; D035683:MicroRNAs / Q000235:genetics*; D015999:Multivariate Analysis; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging; D011237:Predictive Value of Tests; D016016:Proportional Hazards Models; D060888:Real-Time Polymerase Chain Reaction; D012189:Retrospective Studies; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012307:Risk Factors; D013997:Time Factors; D016896:Treatment Outcome; D047368:Tumor Burden
chemical_list: D014408:Biomarkers, Tumor; C548234:MIRN133 microRNA, human; D035683:MicroRNAs
keywords: Biomarker; Colorectal cancer; MicroRNA-133a; Prognosis; Real-time polymerase chain reaction