Involvement of adenomatous polyposis coli (APC)/beta-catenin signalling in human breast cancer

• We studied the relevance of adenomatous polyposis coli (APC)/beta-catenin signalling in the development of breast cancer by analysing the expression of beta-catenin in 54 primary breast tumours (34 ductal and 20 lobular). We showed that 13% of the tumours exhibited upregulated levels of beta-catenin in the cytosol suggesting that defects in APC/beta-catenin signalling components had lowered the rate of beta-catenin degradation. No mutations were observed in the amino-terminal region of beta-catenin, which comprises conserved serine residues important for phosphorylation-dependent degradation of the protein, but the APC protein was altered in 6% of the tumours. Tyrosine phosphorylation of beta-catenin was detected in only one tumour and could, therefore, not have been responsible for the observed increased levels of this protein. Although 9% of the tumours displayed upregulation of c-MYC protein, there was no correlation with beta-catenin overexpression, suggesting that increased beta-catenin expression is not the major cause of c-myc gene activation in breast cancer. It is imperative that elements that selectively drive the oncogenic activity of beta-catenin in breast cancer be identified.

Ämnesord

MEDICIN OCH HÄLSOVETENSKAP  -- Klinisk medicin -- Cancer och onkologi (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Clinical Medicine -- Cancer and Oncology (hsv//eng)

Nyckelord

Adenomatous Polyposis Coli Protein

Adult

Blotting, Western

Breast Neoplasms/genetics

Carcinoma, Ductal, Breast/genetics

Carcinoma, Lobular/genetics

Cell Communication

Cytoskeletal Proteins/metabolism

Female

Humans

Mutation/genetics

Neoplasm Proteins/metabolism

Sweden

Trans-Activators

beta Catenin

Publikations- och innehållstyp

art (ämneskategori)

ref (ämneskategori)