CircRNAs in Lung-intestinal Axis Cancer

The "exterior-interior relationship between the lung and the large intestine" is a basic theory in Traditional Chinese Medicine (TCM), which has been confirmed by mounting evidence, and the lung-intestinal axis can be seen as an extension of this theory. Circular RNAs (circRNAs) are a kind of conserved and structurally stable noncoding RNAs, which have been found to be differentially expressed and associated with the development of cancer in malignant tumors. Many studies have found that circRNAs play an important role in lung and intestinal cancers. This review focuses on circRNAs and reveals that there are common circRNAs that are both highly or poorly expressed in lung-intestinal axis cancers and most of them regulate the proliferation, migration, and invasion of cancer cells by sponging miRNAs. These results not only provide new evidence and research ideas for the "exterior-interior relationship between the lung and the large intestine", but also suggest that circRNAs can be new potential therapeutic targets for the future drug research of lung-intestinal axis diseases.