Post-operative breast cancer patients diagnosed with skeletal metastasis without bone pain had fewer skeletal-related events and deaths than those with bone pain

<p>Abstract</p> <p>Background</p> <p>Skeletal metastases are often accompanied by bone pain. To investigate the clinical meaning of bone pain associated with skeletal metastasis in breast cancer patients after surgery, we explored whether the presence of bone pain was due to skeletal-related events (SREs) or survival (cause specific death, CSD), retrospectively.</p> <p>Methods</p> <p>Consecutive breast cancer patients undergoing surgery between 1988 and 1998 were examined for signs of skeletal metastasis until December 2006. Patients who were diagnosed as having skeletal metastasis were the subjects of this study. Bone scans were performed annually for 5, 7 or 10 years; they were also conducted if skeletal metastasis was suspected. Data concerning bone pain and tumor markers at the time of skeletal metastasis diagnosis, and data relating to various factors including tumors, lymph nodes and hormone receptors at the time of surgery, were investigated. The relationships between factors such as bone pain, SRE and CSD were analyzed using the Kaplan-Meier method and Cox's analysis.</p> <p>Results</p> <p>Skeletal metastasis occurred in 668 patients but the pain status of two patients was unknown, therefore 666 patients were included in the study. At the time of skeletal metastasis diagnosis 270 patients complained of pain; however, 396 patients did not. Analysis of data using Cox's and Kaplan-Meier methods demonstrated that patients without pain had fewer SREs and better survival rates than those with pain. Hazard ratios regarding SRE (base = patients without pain) were 2.331 in univariate analysis and 2.243 in multivariate analysis. Hazard ratios regarding CSD (base = patients without pain) were 1.441 in univariate analysis and 1.535 in multivariate analysis. Similar results were obtained when analyses were carried out using the date of surgery as the starting point.</p> <p>Conclusion</p> <p>Bone pain at diagnosis of skeletal metastasis was an indicator of increased SRE and CSD. However, these data did not support recommendations of follow-up bone surveys in breast cancer patients.</p

Measurement of GTPγS binding to specific G proteins in membranes using G-protein antibodies

AbstractWe developed a novel method to quantitatively measure GTPγS binding to specific G proteins in crude membranes using G-protein antibodies. The basic strategy was that the materials were initially incubated with [35S]GTPγS at 37°C. After 4°C incubation in the wells of an ELISA plate precoated with G-protein antibodies, the radioactivity of each well was counted. This method, using an anti-Gi antiserum and an anti-G3 antiserum, quantitatively and specifically detected the binding of GTPγS to purified G12 and G3. In S49 cell membranes, GTPγS binding to immunoreactive G3 was observed in a time-dependent manner that obeyed first order kinetics, and the rate constant was stimulated ∼tworold in response to isoproterenol. The effect of isoproterenol was not observed in unc mutant membranes. The present method thus makes it possible to quantitatively measure GTPγS binding to specific G proteins in cell membranes

c-Fos protein as a target of anti-osteoclastogenic action of vitamin D, and synthesis of new analogs

Although active vitamin D drugs have been used for the treatment of osteoporosis, how the vitamin D receptor (VDR) regulates bone cell function remains largely unknown. Using osteoprotegerin-deficient mice, which exhibit severe osteoporosis due to excessive receptor activator of NF-κB ligand/receptor activator of NF-κB (RANKL/RANK) stimulation, we show herein that oral treatment of these mice with 1α,25-dihydroxyvitamin D(3) [1α,25(OH)(2)D(3)] inhibited bone resorption and prevented bone loss, suggesting that VDR counters RANKL/RANK signaling. In M-CSF–dependent osteoclast precursor cells isolated from mouse bone marrow, 1α,25(OH)(2)D(3) potently and dose-dependently inhibited their differentiation into multinucleate osteoclasts induced by RANKL. Among signaling molecules downstream of RANK, 1α,25(OH)(2)D(3) inhibited the induction of c-Fos protein after RANKL stimulation, and retroviral expression of c-Fos protein abrogated the suppressive effect of 1α,25(OH)(2)D(3) on osteoclast development. By screening vitamin D analogs based on their c-Fos–suppressing activity, we identified a new analog, named DD281, that inhibited bone resorption and prevented bone loss in ovariectomized mice, more potently than 1α,25(OH)(2)D(3), with similar levels of calcium absorption. Thus, c-Fos protein is an important target of the skeletal action of VDR-based drugs, and DD281 is a bone-selective analog that may be useful for the treatment of bone diseases with excessive osteoclastic activity