MUC1, also known as CD227, is a highly glycosylated transmembrane mucin expressed on the luminal surface of epithelial cells. It protects epithelial cells from extreme factors and has anti-adhesive, immunosuppressive properties, and is involved in cell signaling [1,4]. In normal cells, it functions in the reproductive tract and immune system and protects against infections [4].

In cancer cells, MUC1 expression is upregulated, and its protein structure, glycosylation level, and spatial distribution are altered. It participates in regulating several signaling pathways, influencing tumor cell metabolism, apoptosis, epithelial-mesenchymal transition, and distant metastasis. For example, in neuroendocrine prostate cancer, MUC1-C (encoded by MUC1) suppresses the AR axis, induces pluripotency factors, and activates neural transcription factors, promoting the cancer stem cell state, and targeting MUC1-C inhibits self-renewal and tumorigenicity [3]. In breast cancer, its overexpression and aberrant glycosylation make it an ideal target for immunotherapy [2].

In conclusion, MUC1 has essential functions in normal biological processes but is also significantly involved in cancer progression. Studies on MUC1, especially through models like those related to neuroendocrine prostate cancer, have revealed its role in tumor-associated signaling pathways, providing potential targets for cancer treatment [3].

References:

1. Qing, Liangliang, Li, Qingchao, Dong, Zhilong. 2022. MUC1: An emerging target in cancer treatment and diagnosis. In Bulletin du cancer, 109, 1202-1216. doi:10.1016/j.bulcan.2022.08.001. https://pubmed.ncbi.nlm.nih.gov/36184332/

2. Li, Zhifeng, Yang, Dazhuang, Guo, Ting, Lin, Mei. 2022. Advances in MUC1-Mediated Breast Cancer Immunotherapy. In Biomolecules, 12, . doi:10.3390/biom12070952. https://pubmed.ncbi.nlm.nih.gov/35883508/

3. Kufe, Donald. 2023. Dependence on MUC1-C in Progression of Neuroendocrine Prostate Cancer. In International journal of molecular sciences, 24, . doi:10.3390/ijms24043719. https://pubmed.ncbi.nlm.nih.gov/36835130/

4. Apostolopoulos, Vasso, Stojanovska, Lily, Gargosky, Sharron E. 2015. MUC1 (CD227): a multi-tasked molecule. In Cellular and molecular life sciences : CMLS, 72, 4475-500. doi:10.1007/s00018-015-2014-z. https://pubmed.ncbi.nlm.nih.gov/26294353/