Bone morphogenetic protein signaling enhances invasion and bone metastasis of breast cancer cells through Smad pathway.

Transforming growth factor (TGF)-beta is known to promote tumor invasion and metastasis. Although bone morphogenetic proteins (BMPs), members of the TGF-beta family, are expressed in a variety of human carcinoma cell lines, their roles in tumor progression have not been fully clarified. In this study, we sought to determine the roles of BMPs in the progression of breast cancer bone metastasis using human breast cancer samples and a mouse xenograft model. Immunohistochemical analysis of samples from breast cancer patients as well as a mouse xenograft model of MDA-231-D, highly metastatic human breast cancer cells, revealed phospho-Smad2 and phospho-Smad1/5/8 staining in the nuclei of cancer cells in primary tumor and/or bone metastasis. Using a functional in vivo bioluminescence imaging system, we showed that TGF-beta- and BMP-induced transcriptional pathways are active in bone metastatic lesions in vivo. In addition, both TGF-beta3 and BMP-2 promoted the motility and invasiveness of the MDA-231-D cells in vitro. Moreover, expression of dominant-negative receptors for TGF-beta and/or BMPs in the MDA-231-D cells inhibited invasiveness in vitro and bone metastasis in the xenograft model. These results suggest that BMPs as well as TGF-beta promote invasion and bone metastasis of breast cancer.

Calcium supplementation does not reproduce the pharmacological efficacy of alfacalcidol for the treatment of osteoporosis in rats.

The purpose of this study was to assess whether a nutritional supply of calcium (Ca) could be substituted for alfacalcidol (ALF) administration in preventing bone loss due to estrogen deficiency. Female Wistar-Imamichi rats (8 months old) were ovariectomized (OVX) or sham-operated. OVX rats received ALF administration (0.025, 0.5, or 0.1 microg/kg, p.o., 5 times a week) with standard rodent chow [Ca 1.2%, phosphorus (P) 1.04%], a Ca-enriched diet containing 2%, 4%, or 6% Ca (Ca/P ratio of 2, 4, and 6, respectively), or a Ca/P-enriched diet (Ca/P ratio of 1.2). After 12 weeks of treatment, all rats were killed to harvest the spine, serum, and urine samples. Neither the ALF treatment nor the Ca supplement caused hypercalcemia. In the spine, ALF prevented decreases in bone mineral density (BMD) and compressive strength of lumbar spine induced by OVX. Micro-computed tomographic analysis confirmed that ALF significantly improved the trabecular bone pattern factor and the structure model index and suppressed bone destruction. In contrast, of particular interest, high-dose Ca administration did not have marked effects on bone fragility. Also, when both Ca and P were administered in high doses, BMD and mechanical strength decreased dose-dependently, urinary P excretion significantly increased, and serum parathyroid hormone level increased. Together, it is difficult to adjust the Ca supply through diet alone without disrupting the balance between serum Ca and P levels. Consequently, we conclude that ALF is beneficial for the treatment of osteoporosis, which is not achieved by the use of a Ca supplement.

Anatomy of a patient safety event: a pediatric patient safety taxonomy.

BACKGROUND: Idiosyncratic terminology and frameworks in the study of patient safety have been tolerated but are increasingly problematic. Agreement on standard language and frameworks is needed for optimal improvement and dissemination of knowledge about patient safety. METHODS: Patient safety events were assessed using critical incident analysis, a method used to classify risks that has been more recently applied to medicine. Clinician interviews and clinician reports to a web based reporting system were used for analysis of hospital based and ambulatory care events, respectively. Events were classified independently by three investigators. RESULTS: A pediatric patient safety taxonomy, relevant to both hospital based and ambulatory pediatric care, was developed from the analysis of 122 hospital based and 144 ambulatory care events. It is composed of four main categories: (1) problem type; (2) domain of medicine; (3) contributing factors in the patient (child-specific), environment (latent conditions) and care providers (human factors); and (4) outcome or result of the event and level of harm. A classification of preventive mechanisms was also developed. Inter-rater reliability of classifications ranged from 72% to 86% for sub-categories of the taxonomy. CONCLUSIONS: This patient safety taxonomy reflects the nature of events that occur in both pediatric hospital based and ambulatory care settings. It is flexible in its construction, permits analysis to begin at any point, and depicts the relationships and interactions of elements of an event.

Elevation of circulating plasma cytokines in cancer patients with high plasma parathyroid hormone-related protein levels.

Parathyroid hormone (PTH) and PTH-related protein/peptide (PTHrP) bind to the same PTH/PTHrP receptor and stimulate osteoblasts to secrete pro-inflammatory cytokines like interleukin (IL)-6. In patients with primary hyperparathyroidism, elevation of plasma levels of tumor necrosis factor (TNF)-alpha and IL-6 was also described. We, therefore, postulated that PTHrP secreted from cancer cells stimulates the secretion of cytokines and causes increases in their blood levels. Blood concentrations of several cytokines (TNF-alpha, IL-1beta, IL-5, IL-6, IL-8, IL-11 and IL-12) in cancer-bearing patients with or without elevation of blood PTHrP were measured by ELISA. The patients with high plasma PTHrP levels (n=29, intact PTHrP: 8.5 +/- 1.4 pmol/l, normal: <1.1) had higher serum type 1 collagen C-telopeptide (ICTP). Twenty of the patients were hypercalcemic. Plasma concentrations of TNF-alpha, IL-6 and IL-8 were significantly increased in patients with high PTHrP, in either the presence or absence of hypercalcemia. The concentrations of TNF-alpha and IL-6 were also significantly correlated with those of PTHrP. Our observations indicate that high plasma levels of PTHrP in cancer-bearing patients contribute not only to the development of hypercalcemia, but also to the development of the syndrome caused by an excess of pro-inflammatory cytokines.

Comparison between solitary and multiple skeletal metastatic lesions of breast cancer patients.

BACKGROUND: Breast cancer has been the subject of many recent studies because it is a significant cause of death in women. This study was performed to clarify whether solitary skeletal metastasis has clinical significance compared with multiple skeletal metastasis. PATIENTS AND METHODS: Seven hundred and three patients who developed metastatic bone lesions up to September 2002 after beginning treatment for breast cancer from 1988 to 1998 were included. The lesions were classified first as solitary or multiple based on bone scan results and then according to anatomical distribution. Next, solitary-to-multiple conversion was investigated in patients with solitary skeletal metastasis. Then factors related to solitary or multiple skeletal metastasis were analyzed. The prognosis of skeletal metastasis was compared between patients with solitary or multiple metastatic bone lesions. A Cox proportional hazards model was used to test whether solitary skeletal metastasis compared with multiple skeletal metastasis was an independent factor of survival. RESULTS: Two hundred and eighty-nine patients (41%) had solitary skeletal metastasis and 414 patients (59%) showed multiple skeletal metastasis. The sternum was a frequent site for solitary skeletal metastasis (98 of 289, 34%), while other skeletal sites were more frequent in patients with multiple metastatic bone lesions (P <0.001). Solitary sternal metastatic lesions remained solitary longer than solitary metastatic bone lesions to places other than the sternum (P <0.001), but did not lengthen patient survival times (P = 0.871). The factors related to solitary skeletal metastasis are TNM stage (tumor-node-metastasis) and histology. The patients with earlier stage and favorable histology tend to have solitary skeletal metastasis. The patients with solitary skeletal metastasis lived longer than those with multiple metastatic bone lesions (P <0.001). Multivariate analysis revealed that a solitary metastatic bone lesion (P = 0.002) is an independent favorable prognostic factor in patients with skeletal metastasis. CONCLUSIONS: Solitary skeletal metastasis has a different anatomical distribution and is an independent prognostic factor in patients with skeletal metastasis.

Sentinel node detection using 99mTc-rhenium sulphide colloid in breast cancer patients: evaluation of 1 day and 2 day protocols, and a dose-finding study.

Sentinel node (SN) biopsy is a promising replacement for standard axillary lymph node dissection for the staging of early breast cancer, and various techniques have been studied to identify SNs with dye or radioactive colloid. This study assesses the effect of the dose of radioactivity and the time before biopsy in order to set standards for the use of 99mTc-rhenium sulphide for the detection of SNs in breast cancer patients. Sixty patients with stage T1-2 N0 M0 breast cancer underwent SN biopsy, which was immediately followed by standard axillary dissection to confirm the SN results. For SN biopsy, 99mTc-rhenium colloid was injected peritumorally. A 1 day (morning injection and afternoon surgery) or 2 day (day before afternoon injection and morning surgery) protocol was applied. A dose-finding study was performed simultaneously using 7.4-37 MBq for the 1 day protocol and 37-74 MBq for the 2 day protocol. A scintigram was taken at 2 h for the 1 day protocol and 16 h for the 2 day protocol. After the injection of blue dye, SN biopsy was performed with a gamma probe, followed by standard axillary node dissection. The radiation exposure received by the surgical team during the operation was monitored. Histopathological comparison between SNs and axillary nodes was performed. Patient characteristics that might affect the radiocolloid uptake by SNs were assessed. SNs were identified in all patients regardless of the dose or administration protocol used. Two patients showed false negative pathological SN results, and the negative predictive value was 96% and the positive predictive value was 100%. In addition, radiation exposure to the surgical team and the amount of radioactive surgical waste were low, especially at lower doses. Two groups of patient characteristics were related to SN uptake. One was the body mass index (BMI) and the other was the age or menopausal status. Patients with a larger BMI tended to take up a smaller amount of 99mTc colloid. Older or post-menopausal patients showed lower SN uptake. 99mTc-rhenium sulphide colloid is an efficient radiopharmaceutical for SN detection. Both 1 day and 2 day protocols have equally good efficacy, and the recommended dose is 7.4 MBq for the 1 day protocol and 37 MBq for the 2 day protocol. Patients with larger BMI and older or post-menopausal patients tend to take up less 99mTc colloid.

Comparative study of incadronate and elcatonin in patients with malignancy-associated hypercalcaemia.

The clinical usefulness of incadronate was compared with elcatonin in 26 patients with malignancy-associated hypercalcaemia. Data from 21 and 24 patients could be used to assess efficacy and safety, respectively. Eleven patients were given a single 10-mg intravenous infusion of incadronate and 10 received twice-daily intramuscular injections of 40 IU of elcatonin for 7 consecutive days. After treatment, corrected serum calcium levels decreased significantly in both groups. The anti-hypercalcaemic effect of elcatonin was characterized by its rapid onset, with serum calcium levels reduced 1 day after administration. In contrast, the anti-hypercalcaemic effect of incadronate was more sustained but only became apparent a few days after infusion. Evaluation of symptoms revealed significantly greater improvement rates in the incadronate group compared with the elcatonin group. Adverse drug reactions were observed in three patients in the incadronate group, i.e. mild and transient fever in two cases and exacerbation of disturbance of consciousness in one case. These findings suggest that incadronate produces more marked and sustained hypocalcaemic effects than elcatonin, and that co-administration of these two drugs may yield both rapid and sustained control of malignancy-associated hypercalcaemia.

Clinical effect of intravenous calcitriol administration on secondary hyperparathyroidism. A double-blind study among 4 doses.

BACKGROUND/AIMS: Although the PTH-suppressive effect of intravenous calcitriol has already been demonstrated by various studies, the precise dose-response to calcitriol has not been fully determined for uremic secondary hyperparathyroidism (2HPT). In order to investigate in detail the dose-response of intravenous calcitriol and the adequate initial dose against 2HPT, a randomized prospective double-blind study was conducted. METHOD: One-hundred and sixty-two patients with 2HPT undergoing hemodialysis three times per week were randomly assigned to four calcitriol (Ro21-5535) treatment groups, 0 (placebo), 1, 1.5 or 2 microg. Calcitriol or placebo was given intravenously after each dialysis for 12 weeks under double-blind conditions. RESULTS: Calcitriol dose-dependently reduced both intact-PTH and high-sensitivity assay mid-terminal (HS)-PTH levels. The rate of per-week change in intact-PTH was 0.0% in the placebo group, -7.8% in the 1-microg group, -18.9% in the 1.5-microg group and -24.1% in the 2-microg group. Calcitriol dose-dependently increased the rate of increase in serum Ca adjusted by albumin level. The per-week increases in adjusted serum Ca were -0.01, 0.08, 0.23 and 0.35 mg/dl in the placebo, 1-, 1.5- and 2-microg groups, respectively. Although the degree of PTH suppression was correlated with the adjusted serum Ca increase, by-patients investigation revealed that the number of patients with suppression of PTH despite of no or slight elevation of adjusted serum Ca level was largest in the 1-microg group among the three calcitriol groups. CONCLUSION: Intravenous calcitriol was found to have a clear dose-dependent effect on PTH reduction in patients with 2HPT, and the appropriate initial dose of this agent was determined to be 1 microg per dialysis session.

ED-71, a vitamin D analog, is a more potent inhibitor of bone resorption than alfacalcidol in an estrogen-deficient rat model of osteoporosis.

Although active vitamin D is used in certain countries for the treatment of osteoporosis, the risk of causing hypercalcemia/hypercalciuria means that there is only a narrow therapeutic window, and this has precluded worldwide approval. The results of our previous animal studies have suggested that the therapeutic effect of active vitamin D on bone loss after estrogen deficiency can be dissociated at least partly from its effect of enhancing intestinal calcium absorption and suppressing parathyroid hormone (PTH) secretion. To test this, we compared the effects of ED-71, a hydroxypropoxy derivative of 1alpha,25-dihydroxyvitamin D3, with orally administered alfacalcidol, on bone mineral density (BMD) and the bone remodeling process as a function of their effects on calcium metabolism and PTH, in a rat ovariectomy (ovx) model of osteoporosis. ED-71 increased bone mass at the lumbar vertebra to a greater extent than alfacalcidol, while enhancing calcium absorption (indicated by urinary calcium excretion) and decreasing serum PTH levels to the same degree as alfacalcidol. ED-71 lowered the biochemical and histological parameters of bone resorption more potently than alfacalcidol, while maintaining bone formation markers. These results suggest that active vitamin D exerts an antiosteoporotic effect by inhibiting osteoclastic bone resorption while maintaining osteoblastic function, and that these anticatabolic/anabolic effects of active vitamin D take place independently of its effects on calcium absorption and PTH. The demonstration that ED-71 is more potent in these properties than alfacalcidol makes it an attractive candidate as an antiosteoporotic drug.

Involvement of parathyroid hormone-related protein in experimental cachexia induced by a human lung cancer-derived cell line established from a bone metastasis specimen.

Cachexia often causes deterioration in the quality of life in cancer patients; however, its mechanism remains poorly understood. Cachexia has often been observed in experimental animals with bone metastases, and parathyroid hormone-related protein (PTHrP) plays an important role in the formation of such metastases. We therefore investigated the possible involvement of PTHrP in an experimental cachexia model using human lung-cancer cells (HARA-B). HARA-B cells produce a high amount of PTHrP but no TNF-alpha, IL-6 or leukemia inhibitory factor. The s.c. inoculation of HARA-B cells into nude mice caused reductions in body weight, adipose tissue weight, muscle weight and serum glucose levels. Serum levels of calcium and PTHrP increased. Neutralization of PTHrP with antibody caused rapid weight gain along with a rapid decrease in serum calcium levels. Our findings suggest that PTHrP plays an important role in the development of cancer cachexia. PTHrP therefore is a possible target molecule for the treatment of cancer cachexia.

Post-load glucose measurements in oral glucose tolerance tests correlate well with 1,5-anhydroglucitol, an indicator of overall glycaemic state, in subjects with impaired glucose tolerance.

Using both cross-sectional and longitudinal methods, we investigated the relationship between post-load serum glucose concentration in a 75 g oral glucose tolerance test (OGTT) and overall glycaemic state in subjects with impaired glucose tolerance (IGT). Glycaemic state was assessed by measuring glycated haemoglobin (HbA1c) and the serum concentration of 1,5-anhydroglucitol (1,5-AG). In the cross-sectional study, the concentration of 1,5-AG, while remaining within a normal range, was reduced to a degree proportional to the post-load glycaemic level. Although the correlation between HbA1c and post-load plasma glucose was relatively weak (r=0.281, P<0.001), a significant inverse correlation (r=-0.824, P<0.0001) was found between 1,5-AG and mean post-load plasma glucose concentration in 211 subjects with IGT. Fasting plasma glucose (r=-0.539, P<0.0001) and 2 h plasma glucose (r=-0.621, P<0.0001) were correlated with 1,5-AG less strongly than was post-load glycaemia. Both 1,5-AG and HbA1c were correlated weakly but significantly with the fasting insulin concentration. In the longitudinal study we measured 1,5-AG and mean post-load plasma glucose with an OGTT once yearly for 10 years in 15 subjects with IGT. Strong inverse correlations were seen between 1,5-AG and mean post-load plasma glucose in each subject (range of r values among subjects of -0.584 to -0.978). These findings suggest a close relationship between post-load plasma glucose concentration measured by OGTT and overall glycaemic state in subjects with IGT.

What do breast cancer patients benefit from staging bone scintigraphy?

BACKGROUND: A review and analysis of breast cancer treatment records were conducted to establish criteria for performing disease staging by bone scintigraphy in Japanese breast cancer patients. METHODS: Records from 5538 consecutive Japanese breast cancer patients from January 1988 to December 1998 were reviewed and analyzed to determine bone metastasis status at the time of initial treatment. Correlation between metastasis to bone and factors known before and after surgery was analyzed using logistic regression. RESULTS: The overall incidence of metastasis to bone was 2.13% [95% confidence interval (CI): 1.77-2.55%, 118/5538]. Multivariate logistic analysis revealed that tumor size, nodal involvement and histopathology correlated with metastasis to bone. Patients with tumors larger than 30 mm had a significantly higher probability of metastasis to bone, as did patients with lymph node evaluation results N > or = 1. The incidence of metastasis to bone was 0% in patients with stage 0 disease, 0.08% in stage I patients, 1.09% in stage II patients, 9.96% in stage III patients and 34.04% in stage IV patients. Stage II patients were sub-classified by tumor size T (small, 21-30 mm; and large, 31-50 mm), nodal involvement N and histopathology. The incidence of metastasis to bone in stage II patients was higher in patients with large tumors, scirrhous carcinoma or invasive lobular carcinoma or both. CONCLUSION: Bone metastasis correlated with tumor size (T), lymph node involvement (N) and histopathology. Using the criteria that bone scintigraphy is not necessary in populations with a < 1% incidence of bone metastasis, but is recommended at incidence > 3%, the following conclusions were drawn. Staging by bone scintigraphy provided no benefit to patients whose disease was stage I or less, stage II with small tumors or stage II with large tumors marked by low-grade histopathology (papillotubular cancer). Bone scintigraphy is recommended in patients whose disease is stage II with large tumors marked by high-grade histopathology (scirrhous or invasive lobular cancer), stage III or stage IV. Consequently, staging by bone scintigraphy could be avoided in 71% (3943/5538) of Japanese breast cancer patients.

The serum level of the amino-terminal propeptide of type I procollagen is a sensitive marker for prostate cancer metastasis to bone.

OBJECTIVE: To assess the level of a bone-formation marker, the amino-terminal propeptide of type I procollagen (PINP), for its utility in indicating bone metastasis in patients with prostate cancer. PATIENTS AND METHODS: Several bone formation markers, i.e. PINP, the carboxy-terminal propeptide of type I procollagen (PICP), bone-specific alkaline phosphatase (BALP), and bone Gla protein (BGP), a bone resorption marker (pyridinoline cross-linked carboxy-terminal telopeptide, ICTP), and prostate specific antigen (PSA) were measured in 40 patients without and 25 patients with bone metastasis. No patient had undergone previous treatment, except for six who developed bone metastasis while undergoing hormone therapy. RESULTS: All markers except BGP were significantly higher in patients with bone metastasis than in those without. The levels of PINP correlated best with the extent of disease, although the levels of PSA, BALP and ICTP also correlated well. While PINP had the largest area under the receiver-operator characteristic curve, PSA, BALP and ICTP also produced useful curves. CONCLUSION: The bone formation marker PINP seems to be useful for discriminating patients with and without bone metastasis. PINP may help in the early and accurate diagnosis of bone metastasis in such patients.

[Sentinel node detection of patients with breast cancer by radionuclide method: consideration of radiation safety].

Sentinel node was detected by 99mTc labeled nanocolloid in five patients with breast cancer. Surgery of breast cancer was done at 16 hours after the administration of 74 MBq of 99mTc labeled nanocolloid. Sentinel node was searched by scintigraphy prior to surgery and by gamma-probe during surgery. Radioactivity of injected site, sentinel nodes, blood contaminated gauze, and other garbage was measured by GM detector. Radiation to medical staffs was monitored by a pocket radiation detector and film batches. Sentinel nodes were successfully detected both by scintigraphy and gamma-detector. More than 70% of radioactivity remained in the administered site at 16 hours. Small amount of radioactivity was detectable in the sentinel node. Almost no radioactivity was detectable in blood-contaminated gauze and other garbage. Radiation dose to the main surgeon was 4 to 6 microSv per surgery by a pocket radiation detector. Radiation dose to the assistant surgeon was 2 microSv per surgery. Radiation dose by labeling or injection was 0 to 1 microSv per procedure. No detectable radiation was measured by film batches. It is concluded that the detection of sentinel node by 99mTc labeled nanocolloid is a safe procedure from the point of radiation safety consideration.

Transient splenic accumulation of Tc-99m HMDP caused by megaloblastic anemia.

A case of transient splenic accumulation of the bone-seeking agent Tc-99m HMDP is reported. This effect was caused by transient megaloblastic anemia induced by 5-fluorouracil chemotherapy. The extent of splenic uptake reflected the development and severity of megaloblastic anemia. The mechanism of splenic accumulation is thought to be similar to transient iron deposition in the spleen by megaloblastic anemia.

Gonadotropins stimulate growth of MCF-7 human breast cancer cells by promoting intracellular conversion of adrenal androgens to estrogens.

Estrogen receptor (ER)-positive breast cancers initially respond well to estrogen ablation treatment but finally acquire refractoriness, the phenomenon that is a major clinical problem. Because some breast cancers synthesize estradiol (E(2)) and E(2) synthesis is regulated by gonadotropins in normal ovaries, and because circulating gonadotropins are elevated in postmenopausal women and during estrogen ablation treatment, we hypothesized that gonadotropins might modulate estrogen synthesis/metabolism in breast cancer tissue as well. To test this possibility, MCF-7 cells were treated with dehydroepiandrosterone (DHEA) or human chorionic gonadotropin (hCG; approximately LH), each alone or in combination. Cell growth (3-day treatment) was assayed by the MTT method and estrogen synthesis (24-hour treatment) was measured using the ERE-luciferase reporter system. First, MCF-7 cell growth was stimulated by DHEA in a concentration-dependent manner with a maximal effect at 10(-4) M. Although hCG alone did not have a significant proliferative effect, hCG significantly and dose dependently stimulated MCF-7 cell growth in the presence of a submaximal concentration of DHEA (10(-7 )M). This stimulatory effect of DHEA and hCG was blocked by a pure antiestrogen ICI182,780 and an aromatase inhibitor, arimidex. Using MCF-7 cells transfected with the ERE-luciferase reporter system, hCG treatment was shown to increase ERE-mediated transcription. These results indicate that MCF-7 cells intrinsically converted DHEA into E(2) upon hCG stimulation, then grew their own cells DHEA- and hCG-dependently. We conclude that gonadotropins can act on breast cancer cells and accelerate conversion of DHEA into estrogens, thereby stimulating growth of estrogen-dependent tumor cells. This phenomenon, at least in part, could explain: (1) an increased tissue concentration of E(2) in postmenopausal breast cancer; (2) acquisition of hormone refractoriness during estrogen ablation treatment, and (3) the effectiveness of GnRH antagonist/superagonist in some postmenopausal breast cancer patients.

Modulation of bone remodeling by active vitamin D: its role in the treatment of osteoporosis.

Active vitamin D drugs are used for the treatment of osteoporosis in a number of countries, including Japan. However, their use is controversial. Here, we briefly discuss two issues that are important for understanding the role of active vitamin D (rather than plain vitamin D) in the treatment of osteoporosis: (1) whether or not its skeletal effects are mediated solely through its effects on intestinal calcium absorption in calcium- and vitamin D-replete states, and (2) how it modulates the bone remodeling process.