What is beta-catenin positive?

In summary, high-level nuclear β-catenin staining may be useful as a diagnostic marker for desmoid-type fibromatosis, as only a very limited subset (solitary fibrous tumor, synovial sarcoma, and endometrial stromal sarcoma) of other mesenchymal neoplasms are positive for this marker.

Why is beta-catenin important?

Beta-catenin (β-catenin) is a multifunctional, 90 kD protein that contributes to cell development under normal physiological conditions [55]. β-Catenin is a crucial transcriptional factor in Wingless–Int (Wnt) signaling, and plays important role in stem cell renewal and organ regeneration [56].

Is fibromatosis the same as desmoid tumor?

Desmoid tumors are also known as aggressive fibromatosis or desmoid-type fibromatosis. A desmoid tumor can occur anywhere in the body since connective tissue is found everywhere in your body. Desmoid tumors are often found in the abdomen, as well as the shoulders, upper arms, and thighs.

What is beta catenin stain?

In normal tissues, staining for B-catenin is limited to the membrane. Aberrant nuclear staining can be used diagnostically in selected tumors of the soft tissue (fibromatoses, endometrial stromal sarcoma), pancreas, liver and lung.

How does beta catenin enter the nucleus?

We showed that the nuclear import of both importin β and β-catenin occurs in a Ran-unassisted manner, and that importin β competitively inhibits the import of β-catenin. These results indicate that β-catenin migrates into the nucleus via an interaction with the same site of the NPC as importin β (Figure ​ 7).

What is beta-catenin mutation?

The CTNNB1 gene mutations that cause desmoid tumors usually occur in a region of the gene called exon 3. They change single protein building blocks (amino acids) in the beta-catenin protein. These mutations lead to an abnormally stable beta-catenin protein that is not broken down when it is no longer needed.

What happens when there is too much beta catenin?

We report here that overexpression of beta-catenin results in accumulation of p53, apparently through interference with its proteolytic degradation. This effect involves both Mdm2-dependent and -independent p53 degradation pathways, and is accompanied by augmented transcriptional activity of p53 in the affected cells.

Is fibromatosis a sarcoma?

Desmoid-type fibromatosis (DF) is a rare type of benign (non-cancerous) tumour. It is also sometimes called Desmoid Tumour or aggressive fibromatosis. Patients are treated by sarcoma specialist oncologists who have the skills and experience to treat them.

What causes aggressive fibromatosis?

FAP is caused by a gene mutation that can be passed down from parents to children. It causes numerous growths (polyps) in the colon. Pregnancy. Rarely, a desmoid tumor may develop during or soon after pregnancy.