title: MicroRNAs as a potential prognostic factor in gastric cancer.
abstract: OBJECTIVE
  To compare the microRNA (miR) profiles in the primary tumor of patients with recurrent and non-recurrent gastric cancer.
  
  
  METHODS
  The study group included 45 patients who underwent curative gastrectomies from 1995 to 2005 without adjuvant or neoadjuvant therapy and for whom adequate tumor content was available. Total RNA was extracted from formalin-fixed paraffin-embedded tumor samples, preserving the small RNA fraction. Initial profiling using miR microarrays was performed to identify potential biomarkers of recurrence after resection. The expression of the differential miRs was later verified by quantitative real-time polymerase chain reaction (qRT-PCR). Findings were compared between patients who had a recurrence within 36 mo of surgery (bad-prognosis group, n = 14, 31%) and those who did not (good-prognosis group, n = 31, 69%).
  
  
  RESULTS
  Three miRs, miR-451, miR-199a-3p and miR-195 were found to be differentially expressed in tumors from patients with good prognosis vs patients with bad prognosis (P < 0.0002, 0.0027 and 0.0046 respectively). High expression of each miR was associated with poorer prognosis for both recurrence and survival. Using miR-451, the positive predictive value for non-recurrence was 100% (13/13). The expression of the differential miRs was verified by qRT-PCR, showing high correlation to the microarray data and similar separation into prognosis groups.
  
  
  CONCLUSIONS
  This study identified three miRs, miR-451, miR-199a-3p and miR-195 to be predictive of recurrence of gastric cancer. Of these, miR-451 had the strongest prognostic impact.
authors: Institute of Oncology, Davidoff Center, Rabin Medical Center, Beilinson Hospital, Petach Tikva 49100, Israel. brennerb@clalit.org.il
authors: Baruch
authors: B
authors: Brenner
authors: Moshe B
authors: MB
authors: Hoshen
authors: Ofer
authors: O
authors: Purim
authors: Miriam Ben
authors: MB
authors: David
authors: Karin
authors: K
authors: Ashkenazi
authors: Gideon
authors: G
authors: Marshak
authors: Yulia
authors: Y
authors: Kundel
authors: Ronen
authors: R
authors: Brenner
authors: Sara
authors: S
authors: Morgenstern
authors: Marisa
authors: M
authors: Halpern
authors: Nitzan
authors: N
authors: Rosenfeld
authors: Ayelet
authors: A
authors: Chajut
authors: Yaron
authors: Y
authors: Niv
authors: Michal
authors: M
authors: Kushnir
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000235:genetics*; D005260:Female; D020869:Gene Expression Profiling; D006801:Humans; D008297:Male; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism*; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local; D020411:Oligonucleotide Array Sequence Analysis; D011379:Prognosis; D012189:Retrospective Studies; D013274:Stomach Neoplasms / Q000175:diagnosis* / Q000235:genetics* / Q000473:pathology / Q000601:surgery; D016896:Treatment Outcome
chemical_list: D014408:Biomarkers, Tumor; C552722:MIRN195 microRNA, human; C531201:MIRN451 microRNA, human; D035683:MicroRNAs; C531408:mirn199 microRNA, human