Prognostic value of mature microRNA-21 and microRNA-205 overexpression in non-small cell lung cancer by quantitative real-time RT-PCR

Clin Chem. 2008 Oct;54(10):1696-704. doi: 10.1373/clinchem.2007.101741. Epub 2008 Aug 21.


Background: microRNA (miRNA) expression profiles are being intensively investigated for their involvement in carcinogenesis. We evaluated the prognostic value of mature microRNA-21 (miR-21) and mature microRNA-205 (miR-205) overexpression in non-small cell lung cancer (NSCLC).

Patients and methods: We studied 48 pairs of NSCLC fresh frozen tissue specimens collected at time of surgery and before chemotherapy. Highly specific amplification and quantification of mature miR-21 and mature miR-205 was achieved using looped real time RT-PCR.

Results: miRNA expression, determined by real time RT-PCR, was defined by DeltaDeltaCt measurements. We detected overexpression of mature miR-21 in 25 (52.0%) of the 48 NSCLC paired specimens and overexpression of miR-205 in 31 (64.6%). Overexpression was assessed after comparison of miRNA expression in NSCLC tissues and in their corresponding noncancerous tissues with respect to U6 expression. During the follow-up period, 29 of 48 (60.4%) patients relapsed, and 23 of 48 died (47.9%). Mature miR-21 was upregulated in 16 of 29 (55.2%) patients who relapsed and 15 of 23 (65.2%) patients who died. Mature miR-205 was overexpressed in 19 of 29 patients who relapsed (65.5%) and 15 of 23 patients who died (65.2%). Mature miR-21 overexpression correlated with overall survival (OS) of the patients (P = 0.027), whereas overexpression of mature miR-205 did not.

Conclusions: Our results suggest that overexpression of mature miR-21 is an independent negative prognostic factor for OS in NSCLC patients.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Carcinoma, Non-Small-Cell Lung / genetics*
  • Carcinoma, Non-Small-Cell Lung / pathology
  • Humans
  • Lung Neoplasms / genetics*
  • Lung Neoplasms / pathology
  • MicroRNAs / genetics*
  • Multivariate Analysis
  • Prognosis
  • Reverse Transcriptase Polymerase Chain Reaction / methods*
  • Survival Analysis


  • MicroRNAs