Prognostic significance of microRNA-221/222 expression in cancers: evidence from 1,204 subjects.
BACKGROUND
The prognostic significance of the expression of the miR-221/222 family in cancer remains controversial. We here performed a meta-analysis of published data investigating the effects of miR-221/222 expression on both overall survival (OS) and disease-free survival (DFS) among patients with cancer.


METHODS
A systematic search of the PubMed, Embase, Cochrane, and CNKI databases was performed with the last search being updated on March 15, 2013. The hazard ratio (HR) and its 95% confidence interval (95% CI) were used to assess the strength of association.


RESULTS
A total of 17 studies involving 1,204 subjects were included in this meta-analysis. When assessing the prognostic significance of miR-221 expression, the pooled HR was 1.91 (95% CI: 1.28-2.85, p=0.002) for OS and 1.36 (95% CI: 0.88-2.09, p=0.163) for DFS. When assessing the prognostic significance of miR-222 expression, the pooled HR was 2.15 (95% CI: 1.51-3.06, p<0.0001) for OS and 1.37 (95% CI: 0.45-4.13, p=0.581) for DFS. We also found that an elevated miR-221 expression was significantly associated with poor OS when stratifying by ethnicity, cancer type, statistical methodology, sample, and quality assessment. There was no evidence of publication bias.


CONCLUSIONS
The meta-analysis demonstrates that the elevated expression of miR-221 and miR-222 is associated with poor OS in patients with cancer. The miR-221/222 cluster might be used as a potential therapeutic strategy in clinical practice. More work is required to fully elucidate the role of the miR-221/222 family in human tumors.
Department of Radiation Oncology, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui - China.
Jin
J
Wang
Sha
S
Liu
Guo Ping
GP
Sun
Fang
F
Wang
Yan Feng
YF
Zou
Yang
Y
Jiao
Jie
J
Ning
Jing
J
Xu
D014408:Biomarkers, Tumor / Q000096:biosynthesis* / Q000235:genetics; D006801:Humans; D035683:MicroRNAs / Q000096:biosynthesis* / Q000235:genetics; D009369:Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D057285:Precision Medicine; D011379:Prognosis
D014408:Biomarkers, Tumor; D035683:MicroRNAs; C525709:MIR221, human; C525710:MIR222, human