Characterization of a rat model with site‐specific bone metastasis induced by MDA‐MB‐231 breast cancer cells and its application to the effects of an antibody against bone sialoprotein

Abstract

Metastasis into the skeleton is a serious complication of certain neoplastic diseases such as breast, prostate and lung cancer, but the reasons for this osteotropism are poorly understood. Our aim was to establish a physiologically relevant animal model that is characterized by osteolytic lesions confined to the hind leg of nude rats. For this purpose, we injected 1310 5 MDA-MB-231 human breast cancer cells transfected with GFP into the superficial epigastric artery, which is an anastomosing vessel between the femoral and iliac arteries. As assessed with the aid of X-rays, computed tomography and immunohistochemisty, osteolytic lesions occurred exclusively in the femur, tibia and fibula of the animals. The tumor take rate was 93% in a series of 96 rats and the increase in lesion size was observed up to 110 days after tumor cell inoculation. When applying this animal model to the effects of an antibody against bone sialoprotein (BSP), a significantly reduced osteolytic lesion size was observed after preincubation of cells (2 hr, 600 mg/ml anti-BSP) prior to intra-arterial tumor cell injection resulting in 19 T/C% at day 60 after tumor implantation (p < 0.05). In addition, the osteolytic lesion size was also significantly reduced after s.c. treatment of the animals with the antibody (20 mg/kg anti-BSPx3 within 5 days after tumor implantation), resulting in 30 T/C% at day 60 after tumor cell implantation (p < 0.05). In conclusion, the novel rat model for site-specific osteolytic lesions provides in vivo evidence that preincubation of MDA-MB-231 GFP cells and treatment of rats after tumor implantation with an antibody against BSP significantly reduces the size of lytic lesions in bone. ' 2005 Wiley-Liss, Inc.Key words: nude rat model; MDA-MB-231 human breast cancer cell line; osteolysis; bone metastasis; bone sialoprotein (BSP); anti-BSP antibody Metastasis is a common phenomenon in the course of malignant tumor disease and the major reason for cancer-associated morbidity and mortality. In osteotropic malignancies such as breast, prostate, lung, kidney and thyroid cancer, the skeleton is frequently affected as metastatic site. From these cancers, the prevalence of skeletal disease is greatest in patients with breast or prostate carcinoma who in the advanced stage develop skeletal metastases in 70%. 1 Breast carcinoma patients experience a median survival time of 20 month after the first appearance of a bone metastasis. 2 Such a lesion results in a number of skeletal complications including pathological fractures, bone pain, hypocalcaemia and spinal cord compression. The reasons for the skeleton being the preferential localization site of metastasis in osteotropic cancers are poorly understood.In patients with primary breast cancer, elevated serum bone sialoprotein (BSP) was recognized as prognostic marker of subsequent bone metastasis 3 and was associated with poor survival. 4 BSP is a noncollagenous protein of the extracellular bone matrix and a member of the SIBLING (Small Integrin-Binding Ligand, N-linked Glycop...

Animal Models of Cancer Pain

“…16,31 To investigate metastatic bone cancer, MDA-MB231 human breast cancer cells (5 × 10 5 in 1 ml) were injected into the femoral arteries of nude rats. 12 Osteolytic lesions occurred exclusively in the femur, tibia, and fibula of these animals, and if the tumor cells were preincubated with an antibody against bone sialoprotein, osteolytic lesion size was reduced significantly. In contrast, R3327 prostate cancer cells were injected directly into the left cardiac ventricle, intravenously, or intraosseously into male Copenhagen rats for observation of metastatic lesions and their relationship to pain.…”

Treatment of Breast Cancer Lytic Skeletal Metastasis Using a Model in Nude Rats

“…Among various options that can be envisaged the combination with an agent targeting the pathophysiology of skeletal lesions seems therapeutically attractive. In addition to these studies demonstrating that an IgY-antibody against BSPII was effective in reducing proliferation, colony formation and migration of MDA-MB-231 GFP+ cells in vitro as well as in vivo it could be shown that this treatment induced new bone formation in the aforementioned nude rat model (34,35). Therefore it was the aim of this study to combine a potent bisphosphonate, e.g., zoledronic acid, with the IgY antibody for treating the mammary carcinoma cell line MDA-MB 231 GFP+ , which causes osteolytic lesions in vivo.…”

Cilengitide inhibits metastatic bone colonization in a nude rat model

“…For all procedures, rats were anesthetized using a mixture of nitrous oxide (1 l/min), oxygen (0.5 l/min) and isoflurane (1.5 vol%). MDA-MB-231 cells (10 5 ) were injected into the right superficial epigastric artery as described previously (24). Resulting bone metastases were observed exclusively in the femur, tibia and fibula of the right hind leg.…”