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February 21, 2005: An understanding of normal activity in bone helps us understand how to better control abnormal activity in osteosarcoma. A study by investigators at Indiana University School of Medicine demonstrated for the first time that fluid generated by normal body movement controls the activity of beta-catenin, a protein which undergoes abnormal changes during certain cancers such as osteosarcoma and may be a suitable target in therapy.

One of the ways we keep our skeleton healthy is through normal movement and exercise. Each movement we make generates a rush of fluid through small canals inside our bones. This fluid movement, commonly called fluid shear stress or FSS, signals to bone cells to begin making new bone. Our study found that fluid shear stress activates the protein beta-catenin. This suggests that in response to exercise, activation of beta-catenin may be a normal event. Normally, beta-catenin plays a part in regulating the gene profile within our cells.

However, abnormal changes in beta-catenin activity occur in many types of cancer including breast, colon and even osteosarcoma. In fact, it is currently being studied as a potential target for chemotherapy. Understanding its normal activity in bone can help us understand how to control its abnormal activity in cancer.

Furthermore, our study found that beta-catenin can also control the expression of the gene cyclooxygenase-2 in osteoblasts, cells that produce bone. The cyclooxygenase-2 gene has also been reported to be abnormally regulated in many types of cancers. Therefore, understanding the normal relationship between these 2 genes in osteoblasts will help us understand their function in osteosarcoma.

This study, "Fluid shear stress induces beta-catenin signaling in osteoblasts", was published in a November 2004 issue of Calcified Tissue International.

PubMed Abstract