Circular RNAs as diagnostic biomarker in pancreatic cancer

Pancreatic cancer is one of the causes of death in the world. Unfortunately, common imaging technologies did not succeed in identifying this disease, and because of the absence of sensitive and specific biomarkers, it is not possible to screen and diagnose the disease. Therefore, this disease is usually diagnosed when patient is at an advanced stage of cancer and has lost the chance of surgery, and routine treatments such as radiotherapy and chemotherapy are not very effective. For this reason, the discovery of new biomarkers to overcome the diagnostic and therapeutic problems of pancreatic cancer is essential. Recently, circular RNAs (circRNAs) have been introduced as a group of noncoding RNAs that can play the role of critical regulators in various human diseases including cancer. A lot of studies revealed that circRNAs can have diverse roles in various cancers, including breast, colorectal, lung, renal, gastric, and hepatocellular carcinoma. The results of these researches have demonstrated that change in circRNAs expression levels in the tumor cells affects carcinogenesis, the stages of progression and metastasis of cancer through various mechanisms. Given that several studies have tested the role of circRNAs in pancreatic cancer, we decided to review the mechanisms proposed in these studies to conclude and summarize the work done in this regard.