In vitro bone resorption activity produced by a hypercalcemic adenocarcinoma tumor line (CAC-8) in nude mice

Summary Tumor extracts and conditioned tissue culture media from a canine adenocarcinoma tumor line (CAC-8) propagated in nude mice significantly increasedin vitro bone resorption in neonatal mouse calvaria as measured by release of previously incorporated⁴⁵Ca.In vitro bone resorption activity was induced in a dose-dependent manner, was not suppressible by indomethacin, and was heat- and acid-stable. Gel exclusion chromatography demonstrated peak bone resorbing activity at a relative molecular mass of approximately 28,000. The parathyroid hormone (PTH) antagonist (^8,18norleucine,³⁴tyrosine) bovine PTH (3–34) amide did not inhibit CAC 8-stimulated or (1–34) bPTH-induced bone resorption. There was an increased number of tartrate-resistant, acid phosphatase-positive cells in calvariae exposed to CAC-8 extract. Ultrastructural evaluation of calvaria revealed hypertrophy and maturation of osteoclasts in calvaria exposed to CAC-8 extract. The maturation effects included close contact to bone surfaces and the presence of clear zones and ruffled borders in osteoclasts. Similar structures were observed infrequently in osteoclasts of control calvaria. These data demonstrate that the tumor line (CAC-8) contained activity capable of stimulatingin vitro bone resorption by increasing osteoclast numbers and the activity of existing osteoclasts.     

A hypercalcemic nude rat model that completely mimics human syndrome of humoral hypercalcemia of malignancy

Summary Tumors causing humoral hypercalcemia of malignancy (HHM) were implanted to athymic nude rats. In one of these rat models transplanted with uterine cancer (UCC), a complete reproduction of human HHM syndrome was achieved: hypercalcemia, hypophosphatemia with increased urinary phosphate and cyclic AMP excretion, and suppressed serum 1,25-dihydroxy-vitamin D (1,25(OH)₂D) level. In another hypercalcemic nude rat model implanted with oral cavity cancer (OCC), all the features were similar except for markedly elevated serum 1,25(OH)₂D. Hypercalcemia disappeared by surgical removal of the tumors in both models, confirming the humoral mechanisms for causing these features. Furthermore, in UCC tumor-bearing rats, hypophosphatemia, increased renal phosphate excretion, and reduced serum 1,25(OH)₂D concentration were already present when these rats were only marginally hypercalcemic. These results raise the possibility that the changes in renal tubular phosphate handling and vitamin D metabolism in HHM are not secondary to hypercalcemia but are due to direct effects of the humoral factor(s) that cause this syndrome. Extracts of both tumors exhibited stimulation of cyclic AMP production in osteoblastlike cells, UMR 106, which could be almost completely inhibited by parathyroid hormone (PTH) antagonist, human PTH(3–34). By comparing the nature and characteristics of humoral factor(s) from UCC and OCC models, mechanisms responsible for causing these abnormalities can be explored. Thus, these nude rat models can be useful for elucidating the underlying mechanism of the development of HHM.     

Effects of gallium nitrate in nude mice bearing a canine adenocarcinoma model of humoral hypercalcemia of malignancy: Biochemical, histomorphometric, and ultrastructural investigations

Hypercalcemic nude mice bearing a canine adenocarcinoma (CAC-8) model of humoral hypercalcemia of malignancy (HHM) were treated daily with gallium nitrate (60 mg/kg elemental gallium subcutaneously on day 0 followed by 20 mg/kg day for four days. Concentrations of gallium in bone were undetectable (<0.00005 μg/g bone) in vehicle-treated mice but markedly elevated in gallium-treated mice (>235 ± 6 μg/g bone). Gallium nitrate significantly decreased serum calcium and urinary calcium excretion in tumor-bearing mice compared with vehicle-treated controls. Histomorphometric evaluation of lumbar vertebrae revealed a significant decrease in the number of osteoclasts/mm trabecular bone in gallium-treated tumor-bearing mice compared with controls. Osteoclasts from tumor-bearing mice treated with gallium nitrate were significantly decreased in size, had reduced tartrate-resistant acid phosphatase staining intensity and ultrastructurally had fewer intracytoplasmic vesicles compared with vehicle-treated controls. Osteoclasts in gallium-treated mice were small and flattened with poorly developed cytoplasmic organelles. The findings of this investigation indicated that gallium nitrate reduced serum calcium in an animal model of HHM by inhibiting osteoclastic bone resorption.     

Urinary excretion of parathyroid hormone-related protein fragments in patients with humoral hypercalcemia of malignancy and hypercalcemic tumor-bearing nude mice

To investigate whether parathyroid hormone-related protein (PTHrP), a hypercalcemia-inducing factor responsible for malignancy-associated hypercalcemia (MAH), is excreted into urine of these patients, radioimmunoassay was established using antiserum specific for the C-terminal region of PTHrP-(127-141). Immunoreactive PTHrP (iPTHrP) was detected in the urine of all patients with MAH (n = 6) in whom nephrogenous cyclic AMP excretion was elevated. However, iPTHrP was not detected in the urine of normal subjects (n = 25) or hypercalcemic patients with primary hyperparathyroidism (n = 8). In normocalcemic patients with malignant disorders iPTHrP was not detected in the urine in most cases (24 of 25 patients) but was detectable in 1 of 25 patients. iPTHrP was also detected in the urine of hypercalcemic nude mice transplanted with PTHrP-producing tumors, but not in the urine of control and normocalcemic nude mice transplanted with PTHrP-nonproducing tumor. Furthermore, size-exclusion high-performance liquid chromatography revealed that the molecular weight of iPTHrP is about 2000-6000 daltons in the urine of patients as well as tumor-bearing nude mice. These data indicate that the fragments of the C-terminal region of PTHrP are excreted into the urine of patients with MAH and in a few normocalcemic patients with malignancies, suggesting that the measurement of iPTHrP in the urine is potentially useful in the differential diagnosis of hypercalcemia, particularly in differentiating humoral hypercalcemia of malignancy and primary hyperparathyroidism.     

The effects of dichloromethylene diphosphonate on hypercalcemia and other parameters of the humoral hypercalcemia of malignancy in the rat leydig cell tumor

Summary There is a high frequency of Leydig cell tumors associated with hypercalcemia in the aged Fischer 344 rat. We studied a transplantable tumor cell line (Rice D-6) which is associated with hypercalcemia, hypercalciuria, hypophosphatemia, renal phosphate wasting, increased urinary cyclic adenosine monophosphate (AMP) excretion, absence of bone metastases, increased osteoclastic bone resorption, and suppressed immunoreactive parathyroid hormone (iPTH) concentrations. We examined the ability of dichloromethylene diphosphonate (Cl₂MDP) to lower serum calcium and decrease the parameters of increased bone resorption. We used this drug also as a pharmacologic tool to determine the relationship of hypercalcemia and increased bone resorption to the abnormalities in renal tubular function associated with the humoral hypercalcemia of malignancy. Daily administration of Cl₂MDP before development of hypercalcemia, in doses from 2.5–40 mg/kg body weight subcutaneously, delayed and suppressed both the hypercalcemia and hypercalciuria. There was an increase in bone mass and decrease in both osteoclast number and activity compared with bones from untreated tumor-bearing animals. The urinary hydroxyproline excretion in treated animals declined towards the normal range. There were no significant effects on serum phosphorus, urine phosphorus, or urine cyclic AMP excretion. These data suggest that Cl₂MDP reverses the increased bone resorption that occurs in the humoral hypercalcemia of malignancy, and confirms that diphosphonates are effective agents in the prevention and treatment of increased bone resorption associated with malignant disease. They also suggest that renal phosphate wasting and increased urinary cyclic AMP excretion are not directly related to the hypercalcemia.     

人破骨细胞生成抑制因子编码区基因的克隆及在成肌细胞中的表达

目的：克隆人破骨细胞生成抑制因子（OPG／OCIF）编码区基因并在真核细胞中的表达。方法：以人骨肉瘤细胞系MG63的总RNA为模板，采用RT－PCR法得到OPG／OCIF的编码区cDNA，构建真核表达载体pIRES2-OPG-EGFP，在脂质体介导下转染小鼠成肌细胞系C2C12，经G418压力筛选建立稳定转染人OPG／OCIF的细胞系，共聚焦荧光显微镜及核酸杂交方法检测OPG／OCIF在细胞中的表达，结果：获得的人OPG／OCIF编码区全长cDNA序列与文献报道的核苷酸序列一致，核酸杂交证实稳定转染人OPG／OCIF编码区cDNA的小鼠成肌细胞系中有OPG／OCIF，mRNA的表达。结论：获得人破骨细胞生成抑制因子编码区全长cDNA并证实在真核细胞中稳定表达。     

Frequency and partial characterization of adenylate cyclase-stimulating activity in tumors associated with humoral hypercalcemia of malignancy

Parathyroid hormone-like adenylate cyclase-stimulating activity (ACSA) has previously been identified in small numbers of tumors or tumor-conditioned tissue culture medium derived from patients or animals with humoral hypercalcemia of malignancy (HHM). We examined the frequency with which this ACSA occurred in a large group of tumor extracts derived from patients with HHM (n = 20), and compared this to three control groups: normocalcemia-associated tumors (n = 20), hypercalcemic control tumors (n = 7), and normal, nonmalignant tissue samples (n = 10). Eighteen of 20 HHM-associated tumor extracts displayed ACSA whereas only 4 of 37 controls contained detectable ACSA. ACSA in one tumor was partially purified, using sequential extraction steps and reverse-phase, high-performance liquid chromatography. Highly purified ACSA (4800-fold) also contained potent in vitro bone-resorbing activity. The molecular weight as assessed by gel filtration was approximately 40,000 D. These findings provide strong support for the thesis that the humoral factor which is responsible for the syndrome of HHM is a parathyroid hormone-like adenylate cyclase-stimulating protein.     

Changes in osteoprotegerin and markers of bone metabolism during glucocorticoid treatment in patients with chronic glomerulonephritis

It is well known that long-term glucocorticoid treatment causes osteoporosis, but the precise mechanism remains unclear. Recently, osteoprotegerin (OPG) has been identified as a cytokine that inhibits osteoclast differentiation. We have previously demonstrated that serum OPG is suppressed by glucocorticoids. Therefore, the present study was carried out to clarify the interrelationships between OPG and other markers of bone metabolism during glucocorticoid treatment. Thirteen patients (7 men, 6 women; 44.1 ± 5.9 years old) with chronic glomerulonephritis who were to be treated with glucocorticoids for the first time were chosen for this study. Markers of bone metabolism, including serum OPG, osteocalcin (OC), bone-specific alkaline phosphatase activity (bAP), parathyroid hormone (PTH), tartrate-resistant acid phosphatase (TRAP), and bone mineral density (BMD), were measured before and during the treatment period. Glucocorticoids significantly reduced BMD of the lumbar spine in the 6 month treatment period (p < 0.01). Serum OPG was decreased significantly by glucocorticoids within 2 weeks (p < 0.001), and serum TRAP, a marker of bone resorption, was markedly increased (p < 0.001). On the other hand, there were no remarkable changes in serum PTH. Serum OC and bAP, markers of bone formation, were transiently reduced during the treatment period (p < 0.01). Furthermore, only serum OPG was positively and independently correlated with percentage BMD of age-matched reference (%AMR). These findings imply that glucocorticoid-induced bone loss develops rapidly via enhanced bone resorption and suppressed bone formation. Moreover, the increased bone resorption caused by glucocorticoids may be, at least in part, mediated by inhibition of OPG, not increment of PTH.     

Adenylate cyclase-stimulating,bone-resorbing and B TGF-like activities in canine apocrine cell adenocarcinoma of the anal sac

Summary Canine apocrine cell adenocarcinoma of the anal sac (APO-AS) is a spontaneously occurring tumor that causes humorally medicated hypercalcemia in 90% of cases. To further define the nature of the responsible mediator in APO-AS, we examined tumor extracts from five APO-AS and four control tumors for adenylate cyclase-stimulating activity (ACSA). All extracts from APO-AS contained potent ACSA, whereas the four control tumors did not. The ACSA extracted from one tumor demonstrated a dose response curve parallel to that of synthetic bovinePTH-(1–34) and was 80% inhibited by Nle^8,18,Tyr³⁴ bPTH-(3–34)amide at a concentration of 10⁻⁵ M. Extracts from three APO-AS and three control tumors were also examined forin vitro bone-resorbing activity (BRA). All APO-AS contained significant BRA, stimulating resorption 1.47 to 2.13-fold over basal, whereas none of the control tumors stimulated resorption. Purification of one extract using C18 reverse-phase high pressure liquid chromatography (RP-HPLC) resulted in a single sharp peak of ACSA which was 400-fold purified compared with the initial extract. This pool also contained significant bone-resorbing activity, whereas none of the adjacent pools did. Purification of a second extract using sequential CN and C18 RP-HPLC followed by size exclusion HPLC resulted in material that was at least 10,000-fold purified, and showed co-purification of ACSA and B TGF-like activity.     

The Effect of PTH Antagonist BIM-44002 on Serum Calcium and PTH Levels in Hypercalcemic Hyperparathyroid Patients

BIM-44002, a pure competitive antagonist of parathyroid hormone (PTH), has a high affinity for the PTH/PTHrP receptor in vitro, and can completely inhibit the actions of a PTH agonist in rats in vivo. Toxicology studies in rats and dogs showed BIM-44002 to be devoid of any adverse effects. Therefore we undertook an investigation to evaluate the potential utility of BIM-44002 in lowering elevated serum calcium in three patients with primary hyperparathyroidism. BIM-44002 was administered by continuous intravenous infusion at dosages of 100 μg/hour (370 nmol/hour) for 12 hours, followed by 200 μg/hour for 12 hours, followed by 400 μg/hour for 12 hours. Vital signs and serum ionized and total calcium were monitored hourly and for 3 hours after cessation of the infusion. Blood for PTH determinations was obtained at the same time points. Serum calcium and PTH did not change during and after the infusion of the antagonist. No subject experienced any adverse reactions to the infusion of the antagonist. We conclude that although the PTH antagonist BIM-44002 was effective both in vitro and in vivo in animals, and it was safe in humans, it was not able to lower serum calcium in patients with hyperparathyroidism. Possible reasons for lack of clinical efficacy are discussed.     

巨噬细胞移动抑制因子在狼疮肾炎患者血清和尿液中的表达

目的探讨巨噬细胞移动抑制因子（MIF）在狼疮。肾炎（LN）发病过程中的分子生物学机制及其在疾病进展中的作用。方法选择我院LN患者30例，用酶联免疫吸附方法测定LN患者血清和尿液MIF浓度，并将血清和尿液MIF浓度与狼疮活动指数、24h尿蛋白定量、血尿和肌酐清除率（Ccr）进行相关性分析，以20名健康体检者作对照组。结果LN患者血清和尿液MIF浓度均高于对照组（P〈（）．01）；活动期LN患者治疗后尿液MIF浓度较治疗前降低（P％0．（）1），而血清MIF浓度治疗前、后无统计学差异（P〉0．05），活动期较静止期LN患者血清和尿液MIF浓度升高（P〈0．01），LN患者血清和尿液MIF浓度与狼疮活动指数呈正相关（r分别为0．598和0．641，P〈0．01）；LN患者血清和尿液MIF浓度均与24h蛋白尿定量呈显著正相关（r分别为0．524和0．749，P〈0．01），与血尿和Ccr均无相关性（P〉0．05）。结论LN患者尿液MIF浓度明显升高，与病情活动程度相关，对于判断患者病情的活动有一定价值。     

The effect of low calcium diet, mithramycin, and dichlorodimethylene bisphosphonate on humoral hypercalcemia of malignancy in nude mice transplanted with the canine adenocarcinoma tumor line (CAC-8)

The effect of a low calcium diet, mithramycin, or dichlorodimethylene bisphosphonate were evaluated in nude mice with humoral hypercalcemia of malignancy associated with the transplanted canine adenocarcinoma (CAC-8). Low calcium (0.01%) diet significantly reduced serum calcium levels in hypercalcemic nude mice and reduced urine calcium excretion to control levels. Mithramycin (8 mg/kg) decreased serum calcium concentration and urine calcium excretion to the range of control non-tumor-bearing nude mice at day 5 after a single injection, but there was no change in the number of tartrate-resistant acid phosphatase-positive osteoclasts in lumbar vertebrae. Osteoclasts from CAC 8-bearing nude mice after mithramycin administration were decreased in size, had small ruffled borders, and increased relative size of clear zones. Dichlorodimethylene bisphosphonate (Cl2MDP) (45 mg/kg) partially reduced serum calcium concentration of hypercalcemic tumor-bearing nude mice, decreased urine calcium excretion to control levels, and markedly reduced the numbers of tartrate-resistant acid phosphatase-positive osteoclasts in lumbar vertebrae. Osteoclasts from Cl2MDP-treated nude mice were smaller and had a reduced frequency of ruffled borders than saline-treated hypercalcemic nude mice. In vitro bone resorption induced by CAC-8 extract was significantly reduced by Cl2MDP and mithramycin. The results of these investigations suggest that the hypercalcemia and hypercalciuria associated with HHM in nude mice with CAC-8 are the combined result of altered calcium homeostasis in the bone, kidney, and intestine. Chemotherapeutic agents that specifically affect only bone or feeding a low calcium diet alone may not completely ameliorate the hypercalcemia of HHM.     

植入窗期血清孕激素水平及子宫内膜白血病抑制因子表达对体外受精-胚胎移植结局的预测价值

目的探讨植入窗期血清雌(E2)、孕(P)激素水平及子宫内膜白血病抑制因子(LIF)表达对体外受精-胚胎移植(IVF-ET)结局的影响。方法40例不育患者在行IVF-ET前一周期采用磁分离酶联免疫法测定植入窗期血清E2、P水平;免疫组化SP法和组织学积分H-score法对LIF在子宫内膜的表达定位和半定量分析。IVF-ET后患者分为:妊娠和未妊娠两组。结果植入窗期血清P水平妊娠及未妊娠组分别为(56.59±4.83)(、44.89±3.08)nmol/L,差异有统计学意义(P<0.05);LIF在子宫内膜腔上皮和腺体表达,两组分别为(1.56±0.41)、(1.31±0.32)及(1.45±0.31)、(1.15±0.37),差异有统计学意义(P<0.05)。血清P水平与子宫内膜LIF的表达显著相关(腺体r=0.589,P<0.01;腔上皮r=0.553,P<0.01)。结论植入窗期血清P水平下降及子宫内膜LIF的表达减弱可导致IVF-ET妊娠失败。植入窗期血清P水平和子宫内膜LIF的表达可作为预测IVF-ET成功与否的指标。     

Effect of ketoprofen in topical formulation on vascular endothelial growth factor expression and tumor growth in nude mice with osteosarcoma.

OST cells, a low metastatic cell line established from human osteosarcoma, were inoculated under the periosteum of the ossa cranii of nude mice. Four weeks later, tumors were percutaneously treated for an additional 4 weeks with a patch containing either placebo or ketoprofen (KP). In the placebo group, OST cells formed osteoid and invaded the cranial bone. Tumor mass weighed 3.54 g. Approximately 85% of cells within the tumor expressed proliferating cell nuclear antigen (PCNA), indicating that they were proliferating with a high mitotic activity. Many feeder vessels were located within the tumor. The majority of tumor cells expressed intensely vascular endothelial growth factor (VEGF). In the KP group, invasion of OST cells into the cranial bone was suppressed and the tumor mass was 47% of that of the placebo group. Approximately 65% of cells within the tumor were PCNA-negative, indicating that their growth was arrested. There were considerably fewer feeder vessels within the tumor in the KP group than in the placebo group. Only a small number of cells expressed VEGF. Based on these findings, we concluded that topical administration of KP to nude mice with osteosarcoma inhibited VEGF expression, reduced the development of feeder vessels for supply of nutrients and oxygen, and suppressed tumor growth.