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View Full Version : Keep drinking that milk--dietary calcium deficiency tied 2 incrsd risk of recurrence


Lani
10-03-2007, 07:58 PM
Bone mets, particularly (study in mice--her2 influence not ev aluated, cell line utilized was her2-)

Cancer Res. 2007 Oct 1;67(19):9542-8.
Accelerated bone resorption, due to dietary calcium deficiency, promotes breast cancer tumor growth in bone.

Zheng Y, Zhou H, Modzelewski JR, Kalak R, Blair JM, Seibel MJ, Dunstan CR.
Bone Research Program, ANZAC Research Institute, University of Sydney, Sydney, New South Wales, Australia.
The skeleton is a major site of breast cancer metastases. High bone turnover increases risk of disease progression and death. However, there is no direct evidence that high bone turnover is causally associated with the establishment and progression of metastases. In this study, we investigate the effects of high bone turnover in a model of breast cancer growth in bone. Female nude mice commenced a diet containing normal (0.6%; 'Normal-Ca') or low (0.1%; 'Low-Ca') calcium content. Mice were concurrently treated with vehicle or osteoprotegerin (1 mg/kg/d s.c; n = 16 per group). Three days later (day 0), 50,000 Tx-SA cells (variant of MDA-MB-231 cells) were implanted by intratibial injection. On day 0, mice receiving Low-Ca had increased serum parathyroid hormone (PTH) and tartrate-resistant acid phosphatase 5b levels, indicating secondary hyperparathyroidism and high bone turnover, which was maintained until day 17. Osteoprotegerin increased serum PTH but profoundly reduced bone resorption. On day 17, in mice receiving Low-Ca alone, lytic lesion area, tumor area, and cancer cell proliferation increased by 43%, 24%, and 24%, respectively, compared with mice receiving Normal Ca (P < 0.01). Osteoprotegerin treatment completely inhibited lytic lesions, reduced tumor area, decreased cancer cell proliferation, and increased cancer cell apoptosis. Increased bone turnover, due to dietary calcium deficiency, promotes tumor growth in bone, independent of the action of PTH. Breast cancer patients frequently have low dietary calcium intake and high bone turnover. Treatment to correct calcium insufficiency and/or treatment with antiresorptive agents, such as osteoprotegerin, may be of benefit in the adjuvant as well as palliative setting. [Cancer Res 2007;67(17):9542-8].
PMID: 17909065 [PubMed - in process]

hutchibk
10-03-2007, 08:41 PM
What is 'osteoprotegerin'? Is that Fosamax and Boniva?

Lani
10-03-2007, 11:06 PM
In recent years much has been learned about the signal-
ing mechanisms between osteoblasts and osteoclasts and the
control of bone metabolism in cancer. Osteoprotogerin
(OPG) is a member of the tumor necrosis factor receptor
superfamily which is a natural inhibitor of osteoclast pro-
duction and activity (Fig. 3). OPG acts as a decoy receptor
binding with OPG-ligand, the natural stimulator of osteo-
clast maturation that is produced in large quantities by the
osteoblast [34]. OPG has recently been shown to inhibit can-
cer-induced bone destruction and reduce skeletal pain in
mice [35], and a synthetic version is now entering phase I
trials in cancer patients. If the effects on bone resorption that
have been seen in normal volunteer testing (Amgen—data
on file) are confirmed in a cancer population, this long-act-
ing subcutaneous preparation could be of great importance
in the future