title: MiR-27 as a prognostic marker for breast cancer progression and patient survival.
abstract: BACKGROUND
  MicroRNA-27a (miR-27a) is thought to be an onco-microRNA that promotes tumor growth and metastasis by downregulating ZBTB10. The potential predictive value of miR-27a was studied in breast cancer patients.
  
  
  METHODS
  The expression of miR-27a and ZBTB10 was examined in 102 breast cancer cases using in situ hybridization (ISH) and immunohistochemistry techniques and were evaluated semi-quantitatively by examining the staining index. The Correlation of miR-27a and ZBTB10 expression was analyed by Spearman Rank Correlation. The association of miR-27a and ZBTB10 expression with clinicopathological characteristics was analyzed using the χ(2) test, and their effects on patient survival were analyzed by a log-rank test and the Kaplan-Meier method. Univariate and multivariate Cox regression analyses were used to evaluate the prognostic values of miR-27a and ZBTB10.
  
  
  RESULTS
  miR-27a was markedly up-regulated in invasive breast cancers that expressed low levels of ZBTB10 (P<0.001). A reverse correlation between miR-27a and ZBTB10 was also observed in breast cancer tissue samples (r(s) = -0.478, P<0.001). Furthermore, the expression of miR-27a and ZBTB10 was significantly correlated with clinicopathological parameters, including tumor size, lymph node metastasis and distant metastasis (P<0.05), but not with receptor status. Patients with high miR-27a or low ZBTB10 expression tended to have significantly shorter disease-free survival times (57 months and 53 months, respectively, P <0.001) and overall survival times (58 months and 55 months, respectively, P <0.001). Univariate and multivariate analysis showed that both miR-27a and ZBTB10 were independent prognostic factors of disease-free survival in breast cancer patients (P <0.001), while only miR-27a was an independent predictor of overall survival (P <0.001).
  
  
  CONCLUSIONS
  High miR-27a expression is associated with poor overall survival in patients with breast cancer, which suggests that miR-27a could be a valuable marker of breast cancer progression.
authors.affiliation: Department of Breast Surgery, Sun Yat-Sen Memorial Hospital, Sun-Yat-Sen University, Guangzhou, People's Republic of China.
authors.forename: Wei
authors.initials: W
authors.lastname: Tang
authors.forename: Jiujun
authors.initials: J
authors.lastname: Zhu
authors.forename: Shicheng
authors.initials: S
authors.lastname: Su
authors.forename: Wei
authors.initials: W
authors.lastname: Wu
authors.forename: Qiang
authors.initials: Q
authors.lastname: Liu
authors.forename: Fengxi
authors.initials: F
authors.lastname: Su
authors.forename: Fengyan
authors.initials: F
authors.lastname: Yu
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000235:genetics / Q000378:metabolism; D001943:Breast Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D018572:Disease-Free Survival; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D053208:Kaplan-Meier Estimate; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism; D008875:Middle Aged; D011379:Prognosis; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D014408:Biomarkers, Tumor; C531388:MIRN27 microRNA, human; D035683:MicroRNAs; D012097:Repressor Proteins; C559929:ZBTB10 protein, human