title: Circulating miR-221 directly amplified from plasma is a potential diagnostic and prognostic marker of colorectal cancer and is correlated with p53 expression.
abstract: OBJECTIVE
  Circulating miRNAs exist in serum and plasma and they can be used as a potential noninvasive molecular marker for colorectal cancer (CRC) diagnosis. The present study was to test the availability of direct amplification of miRNAs from plasma without RNA extraction, and to evaluate its clinical application value in CRC.
  
  
  METHODS
  Plasma miR-21, miR-221 and miR-222 levels were determined in 103 CRC patients and 37 healthy normal controls by quantitative reverse transcription-polymerase chain reaction. Immunohistochemical staining for p53, carcinoembryonic antigen (CEA), estrogen receptor (ER) and progesterone receptor (PR) was carried out in the same CRC patient cohort. The correlation between miR-221 levels and protein levels of p53, CEA, ER and PR, clinicopathological features or overall survival was analyzed.
  
  
  RESULTS
  A standard curve shows a good linearity between the log of sample input and C(T) values over three orders of magnitude of plasma miR-21, miR-221 and miR-222. ROC curve analysis reveals that the plasma levels of miR-221 is a potential biomarker for differentiating CRC patients from controls. Kaplan-Meier curve assessment shows that the elevated plasma miR-221 level is a significant prognostic factor for poor overall survival in CRC patients. The immunohistochemistry analysis demonstrates a significant correlation between plasma miR-221 level and p53 expression.
  
  
  CONCLUSIONS
  The direct amplification of plasma miR-221 can be used as a potential noninvasive molecular marker for diagnosis and prognosis of CRC and is correlated with p53 expression.
authors.affiliation: Department of Medical Oncology, Cancer Center, Sun Yat-sen University, Guangzhou 510060, China.
authors.forename: Xing-xiang
authors.initials: XX
authors.lastname: Pu
authors.forename: Guo-liang
authors.initials: GL
authors.lastname: Huang
authors.forename: Hong-qiang
authors.initials: HQ
authors.lastname: Guo
authors.forename: Cheng-cheng
authors.initials: CC
authors.lastname: Guo
authors.forename: Haoran
authors.initials: H
authors.lastname: Li
authors.forename: Shen
authors.initials: S
authors.lastname: Ye
authors.forename: Suxia
authors.initials: S
authors.lastname: Ling
authors.forename: Li
authors.initials: L
authors.lastname: Jiang
authors.forename: Ying
authors.initials: Y
authors.lastname: Tian
authors.forename: Tong-yu
authors.initials: TY
authors.lastname: Lin
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000097:blood; D015179:Colorectal Neoplasms / Q000097:blood* / Q000175:diagnosis / Q000235:genetics; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D035683:MicroRNAs / Q000097:blood* / Q000235:genetics; D008875:Middle Aged; D009367:Neoplasm Staging; D011379:Prognosis; D012334:RNA, Neoplasm / Q000235:genetics*; D012189:Retrospective Studies; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014057:Tomography, X-Ray Computed; D016159:Tumor Suppressor Protein p53 / Q000097:blood / Q000235:genetics*
chemical_list: D014408:Biomarkers, Tumor; D035683:MicroRNAs; D012334:RNA, Neoplasm; D016159:Tumor Suppressor Protein p53; C525709:MIR221, human; C495901:TP53 protein, human