Home
Title Wnt-5a signaling in breast cancer metastasis
Author/s Annette Säfholm
Department/s Experimental Pathology
Full-text Available as PDF
Defence date 2007-11-23
Defence time 09:15
Defence place Föreläsningssalen, Patologi-huset, ingång 78, Universitetssjukhuset MAS, Malmö.
Opponent professor Randall Moon
Publication/Series Lund University Faculty of Medicine Doctoral Dissertation Series
Publishing year 2007
Pages 142
Document type Dissertation
Language English
Publisher Division of Experimental Pathology, Department of Laboratory Medicine Malmö
Abstract English Breast cancer is the most common form of malignancy affecting women in the Western world. Today, anticancer treatment can control primary breast tumors, but treatment and prevention of metastatic disease still represents a major challenge in the management of breast cancer patients. It has been shown that Wnt-5a plays an important role in breast cancer, since loss of that protein is associated with a higher frequency of metastasis.

The findings presented in this thesis show that Wnt-5a inhibits the metastatic behaviour of breast cancer cells by blocking Ca2+-induced NFAT activation. This inhibition is mediated through activation of Yes, Cdc42 and CK1?. Furthermore, based on sequence analysis of the Wnt-5a protein, I identified two peptides with Wnt-5a mimicking ability. One of the peptides was shortened and modified to yield the formylated hexapeptide, Foxy-5, which was able to copy the effects of Wnt-5a on the intracellular signaling, adhesion and migration of breast epithelial cells.

Experiments were performed in which the mammary fat pads of athymic (immunodeficient) BALB/c mice and normal BALB/c mice were inoculated with 4T1 breast cancer cells. Administration of Foxy-5 every fourth day did not lead to any difference in primary tumor growth, whereas it did radically reduce the level of metastasis to lung and liver compared to controls. The mechanism behind the inhibited metastasis formation seemed to be impaired migration and invasion in the breast cancer cells. In addition, the Wnt-5a coreceptor Ror2 was found to be involved in regulation of breast cancer cell migration and to associate with DDR1, a tyrosine kinase receptor that participates in Wnt-5a signaling. These results further emphasize the importance of Wnt-5a in breast cancer metastasis, and they identify a novel potential treatment strategy.
Subject Medicine and Health Sciences
Keywords patologisk anatomi, Patologi (allmän), General pathology, cancer, onkologi, Cytologi, breast cancer, Wnt-5a, migration, pathological anatomy, metastasis, signal transduction, peptides, Cytology, cancerology, oncology
ISBN/ISSN/Other ISSN: 1652-8220
ISBN: 978-91-85897-28-5
Supervisor Tommy Andersson
Part of Wnt-5a/Ca2+-induced NFAT activity is counteracted by Wnt-5a/Yes-Cdc42-casein kinase 1alpha signaling in human mammary epithelial cells.
Part of A formylated hexapeptide ligand mimics the ability of Wnt-5a to impair migration of human breast epithelial cells.

Bookmark and Share