Volume 4 Supplement 2

Abstracts of the 16th International Charles Heidelberger Symposium on Cancer Research

Open Access

MicroRNA-21 in lung cancer: overexpression in metastasis of pulmonary adenocarcinomas and squamous cell carcinomas

  • Maria R Silva1, 2Email author,
  • Paulo Santos2, 4, 5,
  • Isabel Velada4,
  • Catarina Gomes1,
  • M João d’Aguiar1,
  • Lia Teixeira1,
  • João Dinis1,
  • Susana Carmona4,
  • Luisa Cortes5 and
  • Lina Carvalho1, 2, 3, 5
BMC Proceedings20104(Suppl 2):P14

DOI: 10.1186/1753-6561-4-S2-P14

Published: 24 September 2010

MicroRNAs (miRNAs) are a class of naturally occurring small non-coding RNAs that target protein-coding mRNAs at the post-transcriptional level. Expression profiling has identified miRNA signatures in cancers that associate with diagnosis, staging, progression, prognosis, and response to treatment. MiRNAs are ideal biomarkers in FFPE-tissue because, unlike mRNA, miRNA integrity is affected very little by formalin fixation. Previous studies have shown that miR-21 overexpression correlated with poor prognosis in NSCLC patients.

In this study we investigated the expression of mir-21 in primary carcinoma and metastasis and near non-tumor parenchyma.

FFPE samples from surgical specimens and biopsies of 7 pulmonary adenocarcinomas and 5 squamous cell carcinomas and respective metastasis together with normal lung tissue from the same case; these areas were separated by laser-capture microdissection prior to miRNA analysis.

The expression level of miR-21 by qRT-PCR was significantly higher in tumor tissues than in adjacent normal tissues (p = 0.005). The overexpression in the metastasis samples compared to adjacent normal tissue was almost satistically significant (p = 0.051).

MiR-21 was overexpressed in tumor tissues relative to adjacent non-tumor tissues. We found an increase in miR-21 expression in primary carcinoma and metastasis in pulmonary adenocarcinomas when compared with miR-21 lower expression in squamous cell carcinoma. Despite the small sample studied, further investigation may indicate therapeutic and prognostic relevance of this determination, previous studies suggest that miR-21 and has a role in tumor growth, invasion and metastasis by targeting multiple suppressor genes [1]. Therefore, suppression of miR-21 may provide a novel approach for the treatment of advanced cancers through regulation of tumour suppressor genes.

Authors’ Affiliations

Faculdade de Medicina da Universidade de Coimbra, Instituto de Anatomia Patológica
Centro de Investigação em Meio Ambiente, Genética e Oncobiologia (CIMAGO)
Serviço de Anatomia Patológica dos Hospitais da Universidade de Coimbra
Laboratory of Funcional Genomics, Centro de Histocompatibilidade do Centro
Centro de Neurociências e Biologia Celular


  1. Zhu S, Wu H, Wu F, Nie D, Sheng S, Mo YY: MicroRNA-21 targets tumor suppressor genes in invasion and metastasis. Cell Res. 2008, 18: 350-359. 10.1038/cr.2008.24.View ArticlePubMedGoogle Scholar


© Silva et al; licensee BioMed Central Ltd. 2010

This article is published under license to BioMed Central Ltd.