title: MicroRNAs expressed during lung cancer development are expressed in human pseudoglandular lung embryogenesis.
abstract: OBJECTIVE
  MicroRNAs (miRNAs) play a role during mouse embryonic development and are also important in carcinogenesis. In order to investigate whether there are similar patterns of miRNA expression levels in pseudoglandular human embryonic lung and in human lung tumors, we have analyzed 18 miRNAs (the let-7 family, the miR-17-92 cluster, miR-221 and miR-222) in human embryonic lung samples and in paired lung tumor and normal lung tissue samples and correlated the results with clinicopathological characteristics.
  
  
  METHODS
  RNA was obtained from 12 human embryonic lung samples, 33 lung tumor samples and 33 paired normal lung samples. miRNAs were assessed by quantitative real-time PCR.
  
  
  RESULTS
  Members of the let-7 family were downregulated and members of the miR-17-92 cluster and miR-221 were overexpressed both in embryonic lung tissue and in lung tumors. Low levels of let-7c were associated with absence of metastases (p = 0.015), early-stage non-small cell lung cancer (NSCLC, p = 0.05), and smokers (p = 0.009). High levels of miR-106a were associated with small-cell lung cancer (p = 0.031), and high levels of miR-19a with advanced NSCLC (p = 0.008).
  
  
  CONCLUSIONS
  Our study lends support to the model of cancer as an alteration of normal development, as many miRNAs were similarly expressed in early human lung development and stage I-II of lung cancer development.
authors.affiliation: Human Anatomy and Embryology, School of Medicine, University of Barcelona, Barcelona, Spain.
authors.forename: Alfons
authors.initials: A
authors.lastname: Navarro
authors.forename: Ramon M
authors.initials: RM
authors.lastname: Marrades
authors.forename: Nuria
authors.initials: N
authors.lastname: Viñolas
authors.forename: Angels
authors.initials: A
authors.lastname: Quera
authors.forename: Carlos
authors.initials: C
authors.lastname: Agustí
authors.forename: Arturo
authors.initials: A
authors.lastname: Huerta
authors.forename: Jose
authors.initials: J
authors.lastname: Ramirez
authors.forename: Antoni
authors.initials: A
authors.lastname: Torres
authors.forename: Mariano
authors.initials: M
authors.lastname: Monzo
mesh_terms: D000368:Aged; D005260:Female; D020869:Gene Expression Profiling; D006801:Humans; D008168:Lung / Q000196:embryology* / Q000378:metabolism; D008175:Lung Neoplasms / Q000235:genetics* / Q000473:pathology; D008297:Male; D035683:MicroRNAs / Q000032:analysis*; D008875:Middle Aged; D016133:Polymerase Chain Reaction
chemical_list: D035683:MicroRNAs