title: MicroRNA-93 inhibits tumor growth and early relapse of human colorectal cancer by affecting genes involved in the cell cycle.
abstract: OBJECTIVE
  Colorectal cancer (CRC) is associated with high recurrence and mortality. Because deregulation of microRNAs is associated with CRC development and recurrence, the expression levels of microRNAs can be a simple and reliable biomarker to detect postoperative early relapse, thereby helping physicians to treat high-risk patients more efficiently.
  
  
  METHODS
  We used microRNA arrays and observed that microRNA-93 had substantially different expression levels in early (recurrence within 12 months after surgery) and non-early relapse CRC patients. The replication study, which included 35 early relapse and 42 non-early relapse subjects, further confirmed overexpression of microRNA-93 in non-early relapse samples. The in vitro and in vivo effects of microRNA-93 were investigated by examining cell proliferation, migration and invasion, as well as cell cycles, target-gene expression and xenograft in null mice.
  
  
  RESULTS
  Cellular studies showed that the overexpression of microRNA-93 inhibited colon cancer cell proliferation and migration but not invasion. The cell cycle studies also revealed that microRNA-93 caused an accumulation of the G2 population. However, microRNA-93 could not induce cell apoptosis or necrosis. Functional studies showed that microRNA-93 could suppress CCNB1 protein expression leading to cell cycle arrest in the G2 phase. Moreover, microRNA-93 repressed expression of ERBB2, p21 and VEGF, all of which are involved in cell proliferation. MicroRNA-93 also suppressed tumor growth in null mice.
  
  
  CONCLUSIONS
  This study showed that microRNA-93 can inhibit tumorigenesis and reduce the recurrence of CRC; these findings may have potential clinical applications for predicting the recurrence 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: Ming-Feng
authors.initials: MF
authors.lastname: Hou
authors.forename: Ku-Chung
authors.initials: KC
authors.lastname: Chen
authors.forename: Pei-Chien
authors.initials: PC
authors.lastname: Tsai
authors.forename: Szu-Wei
authors.initials: SW
authors.lastname: Huang
authors.forename: Wen-Wen
authors.initials: WW
authors.lastname: Chou
authors.forename: Jaw-Yuan
authors.initials: JY
authors.lastname: Wang
authors.forename: Suh-Hang Hank
authors.initials: SH
authors.lastname: Juo
mesh_terms: D000368:Aged; D001483:Base Sequence; D002453:Cell Cycle / Q000235:genetics*; D015331:Cohort Studies; D015179:Colorectal Neoplasms / Q000235:genetics / Q000473:pathology*; D017931:DNA Primers; D005260:Female; D006801:Humans; D008297:Male; D035683:MicroRNAs / Q000235:genetics / Q000502:physiology*; D008875:Middle Aged; D012008:Recurrence
chemical_list: D017931:DNA Primers; C543350:MIRN93 microRNA, human; D035683:MicroRNAs