Expression of MUC1 in different tumours and its clinical significance (Review)

Mucin 1 (MUC1) was the first discovered transmembrane protein of the mucin family; it normally covers epithelial cells of the mucous membrane, providing lubrication and protection. However, aberrant expression of MUC1 is involved in cancer development, invasion and metastasis. It has been reported that MUC1 upregulation is highly associated with the progression of different epithelial cancer types, such as lung, liver, pancreatic and breast cancer. Therefore, MUC1 can be used as a specific marker and a target for immunotherapy in clinical applications, and the detection of MUC1 expression levels can be used to diagnose the occurrence, metastasis, prognosis and recurrence of cancer. The present review summarizes the abnormal expression of MUC1 in different tumours and discusses its clinical significance, thereby highlighting the potential diagnostic and therapeutic significance of MUC1 in cancer.