RNA-Seq profiling of circular RNAs in human small cell lung cancer

Aim: We aimed to explore the circular RNA (circRNA) profile of small-cell lung cancer (SCLC). Materials & methods: Total RNA was extracted from six paired SCLC tumors and adjacent noncancerous tissues. Next-generation sequencing was performed to identify the circRNA expression profile of SCLC. Results: We found that five circRNAs were significantly upregulated and 30 circRNAs were significantly downregulated in the SCLC tissues. We confirmed the five upregulated and four randomly selected downregulated circRNAs using real-time quantitative PCR. Notably, circ-STXBP5L was selectively upregulated in SCLC samples, but undetectable in the normal control tissues. Bioinformatics analysis demonstrated that circ-STXBP5L may participate in SCLC carcinogenesis by regulating numerous cancer-related pathways. Conclusion: This study may provide new insights into the early diagnosis and development of targeted therapies for SCLC.