Targeted overexpression of BSP in osteoclasts promotes bone metastasis of breast cancer cells.

Bone is one of the most common sites of breast cancer metastasis while bone sialoprotein (BSP) is thought to play an important role in bone metastasis of malignant tumors. The objective of this study is to determine the role of BSP overexpression in osteolytic metastasis using two homozygous transgenic mouse lines in which BSP expression is elevated either in all the tissues (CMV-BSP mice) or only in the osteoclasts (CtpsK-BSP mice). The results showed that skeletal as well as systemic metastases of 4T1 murine breast cancer cells were dramatically increased in CMV-BSP mice.

Overexpression of bone sialoprotein leads to an uncoupling of bone formation and bone resorption in mice.

The purpose of this study was to determine the effects of bone sialoprotein (BSP) overexpression in bone metabolism in vivo by using a homozygous transgenic mouse line that constitutively overexpresses mouse BSP cDNA driven by the cytomegalovirus (CMV) promoter. CMV-BSP transgenic (TG) mice and wildtype mice were weighed, and their length, BMD, and trabecular bone volume were measured. Serum levels of RANKL, osteocalcin, osteoprotegerin (OPG), TRACP5b, and PTH were determined.

Mechanisms of murine lacrimal gland repair after experimentally induced inflammation.

Purpose: The authors recently reported that a severe inflammatory response resulting in substantial loss of acinar cells was induced by a single injection of interleukin-1alpha into the lacrimal gland and that this effect was reversible. The purpose of the present study was to determine the mechanisms involved in lacrimal gland injury and repair.

Methods: Inflammation was induced by direct injection of recombinant human interleukin-1alpha (IL-1alpha, 1 microg in 2 microL) into the exorbital lacrimal glands of anesthetized female BALB/c mice.