To analyze the difference of circular RNA (circRNA) expression profiles between pleural metastatic lung cancer and pleural tuberculosis.

The circRNA expression profiles in 3 paired specimens of pleural metastatic lung cancer and pleural tuberculosis were detected using the human circRNA microarray. After preprocessing and homogenization of the original data, the differentially expressed circRNAs were searched out. The circRNA in pleural metastatic lung cancer showed a greater than 1.5-fold and P≤0.05 compared with pleural tuberculosis was regarded as differentially expressed circRNA and then confirmed by qRT-PCR. After these circRNAs screening according to the principle of higher fold change and better consistency and their putatively targeting miRNAs prediction by bioinformatics software combined with literature review, the circRNAs that potentially contribute to lung cancer development and metastasis were preliminarily identified.

The circRNA expression profile in pleural metastatic lung cancer showed remarkable changes compared with pleural tuberculosis. In pleural metastatic lung cancer, a total of 3 circRNAs showed a greater than 1.5-fold change, and of them, 2 were up- regulated and 1 were down-regulated. The significantly up-regulated circRNA hsa-circ-103 212 (1.671 fold, P=0.0245) and hsa-circ-104 822(1.514 fold, P=0.0478), and significantly down-regulated circRNA hsa- circ-100548 (1.808 fold, P=0.0287) were obtained after screening. Bioinformatics analysis and literature review suggested that hsa-miR-613 and hsa-miR-24-3p was potentially regulated by hsa-circ-104 822 which contributed to the metastasis and development of lung cancer.

The circRNA expression profile in pleural metastasis lung cancer is greatly changed. hsa-circ-104 822 may play important roles in the metastasis and development of lung cancer.