title: The functional significance of microRNA-29c in patients with colorectal cancer: a potential circulating biomarker for predicting early relapse.
abstract: BACKGROUND
  The recurrence of colorectal cancer (CRC) is frequent within the first year of curative resection surgery and may be unavoidable. microRNAs have been suggested to play roles in carcinogenesis and cancer recurrence. We recently identified microRNA-29c (miRNA-29c) as a predictor of early recurrence in CRC. In the present study, we further investigated the functions and serum level of miRNA-29c in relation to early recurrence of CRC.
  
  
  METHODS
  First we further confirmed overexpression of miRNA-29c in non-early relapse subjects. Gain-of-function in vitro studies were used to evaluate the effect of miRNA-29c on cell proliferation, migration, invasion, and cell cycle progression. The colon cancer cell line Caco2 and a stable clone overexpressing miRNA-29c were xenografted to evaluate the in vivo effect of miRNA-29c in null mice. Finally, circulating miRNA-29c was investigated as a potential biomarker for identifying early relapse.
  
  
  RESULTS
  miRNA-29c expression significantly decreased during early relapse compared to non-early relapse in UICC stage II and III CRC patients (P = 0.021). In vitro studies showed that overexpression of miRNA-29c inhibited cell proliferation and migration. The cell cycle studies also revealed that miRNA-29c caused an accumulation of the G1 and G2 population. In vivo, miRNA-29c suppressed tumor growth in null mice. The serum miRNA-29c increased significantly in early relapsed patients compared to non-early elapsed patients (P = 0.012).
  
  
  CONCLUSIONS
  miRNA-29c shows anti-tumorigenesis activity, and preoperative circulating miRNA-29c levels can be used to predict postoperative early relapse of CRC.
authors.affiliation: Department of Medical Genetics, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.
authors.forename: I-Ping
authors.initials: IP
authors.lastname: Yang
authors.forename: Hsiang-Lin
authors.initials: HL
authors.lastname: Tsai
authors.forename: Ching-Wen
authors.initials: CW
authors.lastname: Huang
authors.forename: Ming-Yii
authors.initials: MY
authors.lastname: Huang
authors.forename: Ming-Feng
authors.initials: MF
authors.lastname: Hou
authors.forename: Suh-Hang Hank
authors.initials: SH
authors.lastname: Juo
authors.forename: Jaw-Yuan
authors.initials: JY
authors.lastname: Wang
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D014408:Biomarkers, Tumor / Q000097:blood*; D018938:Caco-2 Cells; D016022:Case-Control Studies; D002453:Cell Cycle; D002465:Cell Movement; D049109:Cell Proliferation; D015179:Colorectal Neoplasms / Q000097:blood* / Q000473:pathology / Q000601:surgery; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D035683:MicroRNAs / Q000097:blood*; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000097:blood* / Q000517:prevention & control; D009368:Neoplasm Transplantation; D017211:Treatment Failure; D047368:Tumor Burden; D055815:Young Adult
chemical_list: D014408:Biomarkers, Tumor; C532045:MIRN29a microRNA, human; D035683:MicroRNAs