Expression pattern of long non-coding RNAs in renal cell carcinoma revealed by microarray.

Background: Recent large-scale transcriptome analyses have found large numbers of transcripts, including that of long non-coding RNAs (lncRNAs), which are aberrant in various diseases, especially cancers. However, it is not clear whether lncRNAs are involved specifically in renal cell carcinoma (RCC). We investigated the expression patterns of lncRNAs in five RCC tumor samples (T) relative to those of matched adjacent non-tumor tissues (N) via microarray.

Methods: A microarray with 33,045 lncRNA probes and 30,215 mRNA probes was used to identify deregulated lncRNAs in five RCC patients. Furthermore, we confirmed the relative expression levels of AK096725 and ENST00000453068 in 70 paired samples by quantitative reverse transcription polymerase chain reaction (qRT-PCR).

Results: The lncRNA microarray revealed 27,279 lncRNAs in RCC samples, of which 480 were significantly upregulated (P<0.05; T/N>1.5) and 417 were significantly downregulated (P<0.05; N/T>1.5) compared with the matched non-tumor samples. In addition, 19,995 mRNAs were detected, of which 458 were significantly upregulated (P<0.05; T/N>1.5) and 413 were significantly downregulated (P<0.05; N/T>1.5). The expression level changes of AK096725 (P = 0.043) and ENST00000453068 (P<0.001) in 70 paired samples were in accord with the microarray data.

Conclusions: The study uncovered expression patterns of lncRNAs in 5 RCC patients, as well as a number of aberrant lncRNAs and mRNAs in tumor samples compared with the non-tumor tissues. The revelation of an association between AK096725 expression and RCC is especially noteworthy. These findings may help to find new biomarkers in RCC.