Detection of differential expression of miRNAs in computerized tomography-guided lung biopsy

Nonsmall-cell lung carcinoma comprises 85% of lung malignancies and is usually associated with a poor prognosis due to diagnosis at advanced stages. Molecular diagnosis of computerized tomography (CT)-guided biopsy has the potential to identify subtypes of lung carcinoma like adenocarcinoma (AC) and squamous cell carcinoma (SCC) along with its molecular stratification. This approach will help predict the genetic signature of lung cancer in individual patients.

Histopathologically proved a CT-guided biopsy sample of lung cancer cases was used to screen for the expression of microRNA (miRNA) earlier quantitated in blood plasma. Primers against hsa-miR2114, hsa-miR2115, hsa-miR2116, hsa-miR2117, hsa-miR449c, and hsa-miR548q with control RNU6 were used to screen 30 AC, 30 SCC, 5 nonspecific granulomatous inflammation, and 8 control samples. Reverse transcription polymerase chain reaction (RT-PCR) data revealed expression of hsa-miR2114 and hsa-miR548q in AC as well as SCC.

RT-PCR data revealed that the expression of hsa-miR2116 and hsa-miR449c was found upregulated in AC while hsa-miR2117 was expressed in SCC cases. Bioinformatic analysis revealed that genes, where these miRNAs are located, were also upregulated while targets of these miRNAs were downregulated.

miRNAs expression pattern in the CT-guided biopsy samples can be used as a potential tool to differentially diagnose lung cancer subtypes. The expression pattern of miRNAs matches very well in blood plasma and tissue samples, albeit levels were very low in the earlier case than later. This approach can also be used for screening mutations and other molecular markers in a personalized manner for the management of lung cancer patients.