MUC1

• OMIM: 113720
• UniProt: P15941

Mucin -1 ( MUC -1) (formerly: CD227, PEM) ( corresponding to the Cancer Antigen 15-3 ) is a 300-400 kDa transmembrane ( embedded in cell membranes ) mucin in vertebrates, which is found in all human organs.

Mucin-1 can be found, for example in the cornea. There is built-in in the cell membranes of the epithelial cells of the cornea. Due to its size and the negative charges It prevents the adhesion of other cells and microorganisms to the epithelial cells. It towers above the microvilli many times and thus prevents bacteria reach the outer Epithelzellwände.

The mucin -1 is expressed on epithelial tumors in numerous adenocarcinomas, lymphomas, and the multiple myeloma, which was an established since 1990 to a tumor marker (CA 15-3 ). Cancer cells lose their polarity and MUC -1 is also formed on the basolateral side of the cell. The resulting reduction in cell adhesion can be regarded as one of the factors at the start of the chain reaction of the formation of metastases of tumor cells. In cancer therapy, this tumor marker is the starting point for several new cancer therapies. For example, the vaccine Stimuvax or the monoclonal antibody Cantuzumab.

Under the name of Cancer Antigen 15-3 (CA 15-3 ) serves MUC1 as a tumor marker for monitoring the course of breast cancer. Similar mucin tumor markers CA 19-9, KL -6, and CA -125.

Serum levels of CA 15-3 than 30 U / ml indicate an active tumor. The sensitivity (proportion of patients in which the marker is positive) in breast cancer is 60-80 % (up to 90 % for metastatic disease) worse in ovarian cancer 40-70 % in other tumors.

The markers used in the routine aftercare / follow-up of breast cancer patients that have been treated with the intent to cure. In incurable, palliative treated cases arises from the variation of tumor markers usually no therapeutic benefit. In other tumors CA 15-3 can also be positive, but the sensitivity for clinical use is too low. For screening of healthy individuals to cancer tumor markers are in principle unsuitable because of the high rate of false - negative findings.

Currently, research is whether the membrane-bound glycopeptide is suitable because of its overexpression in cancer cells as a target for cancer immunotherapy, such as by coupling to a cytotoxic antibodies against CA 15-3.

Sources and References

• Lamerz R ( 1995): Tumor Markers: Implications for diagnosis and therapy. In: Zeller WJ, zur Hausen H ( eds ): Oncology. Ecomed Release 27 update in December 2009, ISBN 978-3-609-76300-2

• Cell Adhesion
• Tumor markers