It is increasingly evident that non-coding RNAs play a significant role in tumour development. However, we still have a limited knowledge of the clinical significance of long non-coding RNAs (lncRNAs) in lung cancer. The FENDRR is a long coding RNA (also named FOXF1-AS1) located in the vicinity of the protein-coding gene FOXF1 at 16q24.1 chromosomal region. Researchers from the University of Granada set out to define the clinic pathological significance of the long-non-coding RNA FENDRR in lung adenocarcinomas. FENDRR expression measured by quantitative PCR was found significantly downregulated (p<0.001) in lung adenocarcinoma samples in comparison with their normal adjacent tissues (n=70). RNA in situ hybridization (RNA-FISH) corroborated independently the down-regulation of FENDRR. Interestingly, the expression of FENDRR correlated positively (p<0.001) with the expression of its protein-coding neighbor gene FOXF1. Additionally, FOXF1 expression was also found downregulated in adenocarcinomas compared to normal samples (p<0.001) and its expression was significantly correlated with overall survival alone (p=0.003) or in combination with FENDRR expression (p=0.01).
Identification process of somatic variants in FENDRR and FOXF1
(A) Schematic of bioinformatics SNV detection workflow. (B) Extraction of functionally relevant somatic mutations for FOXF1 and FENDRR in lung cancer. Variants were filtered for annotation in dbSNP, 1000genomes, ExAC, NCI60, somatic and functionally impairment. From dbSNP or the 1000 genomes variants with frequencies above 1% were excluded.
In conclusion, these data support that FENDRR and FOXF1 expression is decreased in lung adenocarcinoma and should be considered as new potential diagnostic/prognosis biomarkers.