Markers of type I collagen degradation and synthesis in the monitoring of treatment response in bone metastases from breast carcinoma

Effects of gold nanostructures on differentiation of mesenchymal stem cells

Nanoparticles are nanocrystals with complex facets and defective structures that do not adopt an idealised shape. Various physicochemical parameters of nanoparticles, such as surface composition, size, and stiffness, can regulate differentiation in mesenchymal stem cells (MSCs), but the influence of shapes with many edges and corner regions has not been investigated. Herein, we investigated the effects of two gold nanostructures modified with 11-mercaptoundecanoic acid, namely gold nanocubes (MUA-AuNCs) and nanooctahedras (MUA-AuNOs), on viability and differentiation in rat bone marrow MSCs (bMSCs). Analysis of cytotoxicity and proliferation demonstrated good biocompatibility, with concentrations <100 μg·mL^-1 not significantly different from untreated controls. Alkaline phosphatase activity and Alizarin Red S staining revealed weaker potential for bMSCs to differentiate into osteoblasts following treatment with both low (5 μg·mL^-1) and high (25 μg·mL^-1) concentrations of the gold nanostructures. By contrast, Oil Red O staining showed that both nanostructures enhanced adipogenic differentiation, and upregulated peroxisome proliferator-activated receptor gamma (PPARγ) and fatty acid binding protein-4 (Fabp4) expression at both mRNA and protein levels. The effects on differentiation were both structure- and dose-dependent; MUA-AuNOs were more effective for enhancing adipogenic differentiation and weakening osteogenic differentiation, possibly due to generating higher levels of reactive oxygen species (ROS). These findings lay the foundation for using these nanoparticles as ex vivo labels in MSC-based imaging and therapy.

Usefulness of Bone Formation Markers in Breast Cancer

The skeleton is the main site affected by metastases and breast cancer is the most frequent tumor to invade bone. The assessment of bone metastases is difficult and biochemical markers of bone formation (BFMs) could be a promising alternative. Although the essential role of osteoblasts in the metastatic process of bone destruction is now well established, little attention has been paid to BFMs. We conducted a Medline search for studies about BFMs in breast cancer. Our review allows us to conclude that BFMs have high specificity but low sensitivity for the diagnosis of bone metastases. The available biochemical markers cannot replace imaging techniques for the diagnosis of bone metastases. Several studies indicate that BFM serum levels reflect total tumor burden in the skeleton. BFM levels are higher in patients with blastic lesions compared to those with lytic lesions. Serial measurements of BFMs could be useful for the clinical assessment of response to antineoplastic treatment or to bisphosphonate therapy. Besides markers of bone resorption, biochemical markers of bone formation are a promising alternative for the assessment of metastatic bone disease, but large prospective studies are needed to address this important issue.

The effect of different hydroxyapatite microparticles on the osteogenic differentiation of MC3T3-E1 preosteoblasts

HA microparticles with different sizes and shapes played obvious different roles in promoting the osteogenic differentiation of MC3T3-E1 preosteoblasts. HA microspheres played a better role in promoting the osteogenic differentiation of MC3T3-E1 preosteoblasts than HA whiskers.

Radiological features of experimental staphylococcal septic arthritis by micro computed tomography scan

BACKGROUND

Permanent joint dysfunction due to bone destruction occurs in up to 50% of patients with septic arthritis. Recently, imaging technologies such as micro computed tomography (μCT) scan have been widely used for preclinical models of autoimmune joint disorders. However, the radiological features of septic arthritis in mice are still largely unknown.

METHODS

NMRI mice were intravenously or intra-articularly inoculated with S. aureus Newman or LS-1 strain. The radiological and clinical signs of septic arthritis were followed for 10 days using μCT. We assessed the correlations between joint radiological changes and clinical signs, histological changes, and serum levels of cytokines.

RESULTS

On days 5-7 after intravenous infection, bone destruction verified by μCT became evident in most of the infected joints. Radiological signs of bone destruction were dependent on the bacterial dose. The site most commonly affected by septic arthritis was the distal femur in knees. The bone destruction detected by μCT was positively correlated with histological changes in both local and hematogenous septic arthritis. The serum levels of IL-6 were significantly correlated with the severity of joint destruction.

CONCLUSION

μCT is a sensitive method for monitoring disease progression and determining the severity of bone destruction in a mouse model of septic arthritis. IL-6 may be used as a biomarker for bone destruction in septic arthritis.

Fe3O4/BSA particles induce osteogenic differentiation of mesenchymal stem cells under static magnetic field

Differentiation of stem cells is influenced by many factors, yet uptake of the magnetic particles with or without magnetic field is rarely tackled. In this study, iron oxide nanoparticles-loaded bovine serum albumin (BSA) (Fe₃O₄/BSA) particles were prepared, which showed a spherical morphology with a diameter below 200 nm, negatively charged surface, and tunable magnetic property. The particles could be internalized into bone marrow mesenchymal stem cells (MSCs), and their release from the cells was significantly retarded under external magnetic field, resulting in almost twice intracellular amount of the particles within 21 d compared to that of the magnetic field free control. Uptake of the Fe₃O₄/BSA particles enhanced significantly the osteogenic differentiation of MSCs under a static magnetic field, as evidenced by elevated alkaline phosphatase (ALP) activity, calcium deposition, and expressions of collagen type I and osteocalcin at both mRNA and protein levels. Therefore, uptake of the Fe₃O₄/BSA particles brings significant influence on the differentiation of MSCs under magnetic field, and thereby should be paid great attention for practical applications.

STATEMENT OF SIGNIFICANCE

Differentiation of stem cells is influenced by many factors, yet uptake of the magnetic particles with or without magnetic field is rarely tackled. In this study, iron oxide nanoparticles-loaded bovine serum albumin (BSA) (Fe₃O₄/BSA) particles with a diameter below 200nm, negatively charged surface, tunable Fe₃O₄ content and subsequently adjustable magnetic property were prepared. The particles could be internalized into bone marrow mesenchymal stem cells (MSCs), and their release from the cells was significantly retarded under external magnetic field. Uptake of the Fe₃O₄/BSA particles enhanced significantly the osteogenic differentiation of MSCs under a constant static magnetic field, while the magnetic particles and external magnetic field alone do not influence significantly the osteogenic differentiation potential of MSCs regardless of the uptake amount. The results demonstrate a potential magnetic manipulation method for stem cell differentiation, and also convey the significance of careful evaluation of the safety issue of magnetic particles in real an application situation.

Phase II studies of two different schedules of dasatinib in bone metastasis predominant metastatic breast cancer: SWOG S0622

Bone metastases from breast cancer are common, causing significant morbidity. Preclinical data of dasatinib, an oral small molecule inhibitor of multiple oncogenic tyrosine kinases, suggested efficacy in tumor control and palliation of bone metastases in metastatic breast cancer (MBC). This clinical trial aimed to determine whether treatment with either of 2 dose schedules of dasatinib results in a progression-free survival (PFS) >50 % at 24 weeks in bone metastasis predominant MBC, to evaluate the toxicity of the 2 dosing regimens, and explore whether treatment results in decreased serum bone turnover markers and patient-reported "worst pain." Subjects with bone metastasis predominant MBC were randomly assigned to either 100 mg of dasatinib once daily, or 70 mg twice daily, with treatment continued until time of disease progression or intolerable toxicity. Planned accrual was 40 patients in each arm. The primary trial endpoint was PFS, defined as time from registration to progression or death due to any cause. Median PFS for all eligible patients (79) was 12.6 weeks (95 % CI 9.1-16.7). Neither cohort met the threshold for further clinical interest. There were no significant differences in PFS by randomized treatment arm (p = 0.85). Toxicity was similar in both cohorts, with no clear trend in serum biomarkers of bone turnover or patient-reported pain. Dasatinib was ineffective in controlling bone-predominant MBC in a patient population, unselected by molecular markers. Further study of dasatinib in breast cancer should not be pursued unless performed in molecularly determined patient subsets, or rational combinations.

Combinational effect of matrix elasticity and alendronate density on differentiation of rat mesenchymal stem cells

Differentiation of mesenchymal stem cells (MSCs) is regulated by multivariate physical and chemical signals in a complicated microenvironment. In this study, polymerizable double bonds (GelMA) and osteo-inductive alendronate (Aln) (Aln-GelMA) were sequentially grafted onto gelatin molecules. The biocompatible hydrogels with defined stiffness in the range of 4-40 kPa were prepared by using polyethylene glycol diacrylate (PEGDA) as additional crosslinker. The Aln density was adjusted from 0 to 4 μM by controlling the ratio between the GelMA and Aln-GelMA. The combinational effects of stiffness and Aln density on osteogenic differentiation of MSCs were then studied in terms of ALP activity, collagen type I and osteocalcin expression, and calcium deposition. The results indicated that the stiffness and Aln density could synergistically improve the expression of all these osteogenesis markers. Their osteo-inductive effects are comparable to some extent, and high Aln density could be more effective than the stiffness.

Influence of bovine serum albumin coated poly(lactic-co-glycolic acid) particles on differentiation of mesenchymal stem cells

The presence of PLGA–BSA particles can induce osteogenesis differentiation of mesenchymal stem cells, and meanwhile inhibit their adipogenic differentiation.

Response of Bone Resorption Markers to Aristolochia longa Intake by Algerian Breast Cancer Postmenopausal Women

Aristolochia longa is widely used in traditional medicine in Algeria to treat breast cancer. The aim of the present study was to investigate the response of bone resorption markers to A. longa intake by Algerian breast cancer postmenopausal women. According to the A. longa intake, breast cancer patients were grouped into A. longa group (Al) (n = 54) and non-A. longa group (non-Al) (n = 24). 32 women constituted the control group. Bone resorption markers (from urine) pyridinoline (PYD) and deoxypyridinoline (DPD) were determined by HPLC. Serum and urinary creatinine, uric acid, and urea were measured. 1 g of A. longa intake resulted in significant rise of renal serum markers and a pronounced increase of bone resorption markers. The intake of A. longa roots is detrimental for kidney function and resulted in high bone resorption, maybe due to the reduction in renal function caused by the aristolochic acids contained in the roots.

Serum biomarkers of bone metabolism in castration-resistant prostate cancer patients with skeletal metastases: results from SWOG 0421

BACKGROUND

Prior studies suggest that elevated markers of bone turnover are prognostic for poor survival in castration-resistant prostate cancer (CRPC). The predictive role of these markers relative to bone-targeted therapy is unknown. We prospectively evaluated the prognostic and predictive value of bone biomarkers in sera from CRPC patients treated on a placebo-controlled phase III trial of docetaxel with or without the bone targeted endothelin-A receptor antagonist atrasentan (SWOG S0421).

METHODS

Markers for bone resorption (N-telopeptide and pyridinoline) and formation (C-terminal collagen propeptide and bone alkaline phosphatase) were assayed in pretreatment and serial sera. Cox proportional hazards regression models were fit for overall survival. Models were fit with main effects for marker levels and with/without terms for marker-treatment interaction, adjusted for clinical variables, to assess the prognostic and predictive value of atrasentan. Analysis was adjusted for multiple comparisons. Two-sided P values were calculated using the Wald test.

RESULTS

Sera from 778 patients were analyzed. Elevated baseline levels of each of the markers were associated with worse survival (P < .001). Increasing marker levels by week nine of therapy were also associated with subsequent poor survival (P < .001). Patients with the highest marker levels (upper 25th percentile for all markers) not only had a poor prognosis (hazard ratio [HR] = 4.3; 95% confidence interval [CI] = 2.41 to 7.65; P < .001) but also had a survival benefit from atrasentan (HR = 0.33; 95% CI = 0.15 to 0.71; median survival = 13 [atrasentan] vs 5 months [placebo]; P interaction = .005).

CONCLUSIONS

Serum bone metabolism markers have statistically significant independent prognostic value in CRPC. Importantly, a small group of patients (6%) with highly elevated markers of bone turnover appear to preferentially benefit from atrasentan therapy.

Assessment of Response to Therapy for Bone Metastases: Is it Still a Challenge in Oncology?

Bone is one of the most common sites of metastases from cancer. Most anticancer treatments are highly toxic but only a fraction of all patients respond to them. Guidelines are needed to evaluate the response in the routine practice of oncology as well as in clinical trials in which new treatment options are evaluated. All current imaging procedures have major limitations. This article reviews old and new criteria for response evaluation. The major problem of accurate response evaluation in bone disease is discussed in detail. Some examples from our daily practice illustrate the difficulties. The indications for bone biopsy are also reviewed.

A randomized phase II trial of the matrix metalloproteinase inhibitor BMS-275291 in hormone-refractory prostate cancer patients with bone metastases

BACKGROUND

BMS-275291 is a selective matrix metalloproteinase inhibitor (MMPI) that does not inhibit sheddases implicated in the dose-limiting arthritis of older MMPIs. We conducted a randomized phase II trial of two doses of BMS-275291 (1,200 versus 2,400 mg) in hormone-refractory prostate cancer (HRPC) patients with bone metastases to probe for a dose-response relationship and to assess differential toxicities. Serial serum and urine specimens were collected to assess for markers of bone metabolism.

METHODS

The primary end point was 4-month progression-free survival (PFS). Eligibility criteria included documentation of androgen-independent disease (including anti-androgen withdrawal), skeletal metastasis, adequate end-organ function and performance status, and no more than one prior chemotherapy regimen. Patients were randomized to 1,200 mg orally once daily (arm A) or 1,200 mg orally twice daily (arm B). Response was assessed every 56 days.

RESULTS

Eighty patients were enrolled: 39 in arm A and 41 in arm B. There were no responders by prostate-specific antigen or measurable disease to treatment. Stable disease was noted at 8 weeks in 39% of patients in arm A and in 17% of patients in arm B. Progression of disease at 8 weeks was seen in 61% of patients in arm A versus 83% of patients in arm B. Median survival time was 21.6 months (95% confidence interval, 17.5; not reached), whereas median PFS time was 1.8 months (95% confidence interval 1.74; 2) for all patients. Patients in arm A had a median survival time that was not reached, whereas patients on arm B has a median survival time of 21 months (P = 0.2). PFS at 4 months favored arm A: 22% versus 10% (log-rank, P = 0.008). Grade 3 toxicities occurred in 5 (13%) patients in arm A and in 9 (22%) patients in arm B. Grade 4 toxicities were uncommon (only 4% of patients): one each of thrombosis, fatigue, and motor neuropathy was seen in the arm B. Bone marker studies showed that baseline serum levels of N-telopeptide, osteocalcin, procollagen I NH2-terminal propeptide, and PICP had prognostic significance for PFS and/or overall survival.

CONCLUSIONS

Regardless of dose schedule, BMS-275291 was well tolerated in HRPC patients and had no dose-limiting arthritis. Toxicities differed modestly according to the dose schedule employed. As overall survival and PFS favored the once daily schedule, this dose schedule is recommended for future studies. Baseline markers of bone metabolism may have prognostic value in HRPC patients with bone metastases.

Human mesenchymal stem cell derived osteoblasts degrade organic bone matrix in vitro by matrix metalloproteinases

Some recent studies have suggested that cells of mesenchymal origin might participate in the organic bone matrix dissolution. In the present study, collagen synthesis and degradation by human mesenchymal stem cell (MSC) derived cells were studied at early stage of osteoblast differentiation using a special two-stage in vitro culture model. In this model, cells were cultured on bovine bone slices, which were first resorbed by osteoclasts. Synthesis of type I collagen was markedly enhanced when mesenchymal cells were cultured on bone matrix. After thorough osteoclast removal, MSC derived cells were capable of degrading the organic bone matrix, and caused a release of type I collagen degradation product (ICTP) into the culture medium. This was inhibited by matrix metalloproteinase (MMP) inhibitor, while cysteine proteinase inhibitor or estrogen had no inhibitory effect. Western blot analysis or gelatin zymography confirmed the presence of MMP-2, -8, -13 and -14, but not MMP-1 or -9, in the differentiated cells. 17beta-Estradiol was found to increase the expression of MMP-2 and -14 by these cells. Finally, scanning electron microscopy showed that the differentiating human MSCs were capable of degrading organic bone matrix remnants from the bottom of the resorption lacunae. These data support the hypothesis that collagen cleavage by the same cells that are subsequently responsible for bone formation is MMP mediated process and is an important step coupling bone formation into bone resorption.

Proteinase Activity in Human and Murine Saliva as a Biomarker for Proteinase Inhibitor Efficacy

As molecularly targeted agents reach the clinic, there is a need for assays to detect their presence and effectiveness against target molecules in vivo. Proteinase inhibitors are one example of a class of therapeutic agent for which satisfactory methods of identifying successful target modulation in vivo are lacking. This is of particular importance while these drugs are in clinical trials because standard maximum-tolerated dose-finding studies often are not suitable due to lack of toxicity. Saliva represents a readily accessible bodily fluid that can be repeatedly sampled and used for assaying in vivo effects of systemic drugs. Here we show the development of a simple assay that can be used to measure proteinase activity in saliva and proteinase inhibition after systemic treatment with three different proteinase inhibitors. A variety of gelatinolytic activities present in human and murine saliva have been assayed with a fluorescent dye-labeled substrate and assigned to different proteinase categories by inclusion of specific classes of inhibitors. Treatment of mice with either matrix metalloproteinase inhibitors or a urokinase inhibitor for a period as short as 48 hours results in levels of the drugs that can be detected in saliva by mass spectrometry and concomitant decreases in salivary proteinase activity, thus demonstrating that these inhibitors successfully modulate their targets in vivo.

Evaluation of the clinical value of bone metabolic parameters for the screening of osseous metastases compared to bone scintigraphy

Background

Bone metastases are common in many types of cancer. As screening methods different imaging modalities are available. A new approach for the screening of osseous metastases represents the measurement of bone metabolic markers. Therefore aim of this study was to evaluate the usefulness of the determination of bone metabolic markers aminoterminal propeptide of type I procollagen (PINP, osteoblastic activity) and the carboxyterminal pyridinoline cross-linked telopeptide of type I collagen (ICTP, osteoclastic activity) for the detection of bone metastases associated with other malignancies.

Methods

88 patients aged 21 – 82 years with malignant tumors were prospectively studied. The serum concentrations of PINP and ICTP were measured and compared to the results of bone scintigraphy, radiological bone series, CT, MRI and clinical follow-up.

Results

Osseous metastases were found in 21 patients. 19 of them were correctly identified by bone scintigraphy (sensitivity: 90%). For bone metabolic markers results were as follows: ICTP sensitivity: 71%, specificity: 42%; PINP sensitivity: 24%, specificity: 96%.

Conclusions

As markers of bone metabolism PINP and ICTP showed low sensitivity and/or specificity for the detection of osseous metastases. The presented markers did not seem to be sufficient enough to identify patients with bone metastases or to replace established screening methods.

Synthesis and maturation of type I and type III collagens in endometrial adenocarcinoma

OBJECTIVE

The structure and distribution of type I and type III collagens in the extracellular matrix of malignant endometrium was evaluated for their roles in the development and progression of this neoplasm.

STUDY DESIGN

Collagen synthesis and deposition in endometrial adenocarcinomas was determined by immunohistochemical analysis of type I and type III procollagen and verified by computer-assisted morphometry and in situ hybridization.

RESULTS

In the stroma of well-differentiated adenocarcinomas increased intracellular collagen synthesis was observed in fibroblastic cells as well as increased extracellular formation of newly synthesized type I and type III procollagen. Collagen maturation was also rapid. In moderately differentiated tumors, destruction and dissolution occurred around invading islets, concomitantly with decreased deposits of both collagens, despite increases in corresponding mRNAs. In poorly differentiated neoplasms, solid epithelial islets coexisted with sparse and distinctly collagen-positive stroma. Poorly differentiated neoplasms also contained tumor cells exhibiting intracellular collagen staining as well as in situ hybridization signals. In highly malignant papillary adenocarcinomas, the tumor cells induced distinctly increased collagen synthesis and deposition of newly synthesized collagen but not the mature cross-linked protein.

CONCLUSIONS

In malignancy, compression of surrounding stroma and a fibroproliferative response with increased collagen synthesis and deposition may prevent tumor growth. In more advanced lesions, stromal dissolution may permit tumor spread and in highly malignant lesions an abnormal stroma may promote neoplasm progression.

Matrix metalloproteinases (MMP) and cathepsin K contribute differently to osteoclastic activities

The best established proteolytic event of osteoclasts is bone matrix solubilization by the cysteine proteinase cathepsin K. Here, however, we draw the attention on osteoclastic activities depending on matrix metalloproteinases (MMPs). We discuss the observations supporting that MMPs contribute significantly to bone matrix solubilization in specific areas of the skeleton and in some developmental and pathological situations. Our discussion takes into account (1) the characteristics of the bone remodeling persisting in the absence of cathepsin K, (2) the ultrastructure of the resorption zone in response to inactivation of MMPs and of cathepsin K in different bone types, (3) bone resorption levels in MMP knockout mice compared to wild-type mice, (4) the identification of MMPs in osteoclasts and surrounding cells, and (5) the effect of different bone pathologies on the serum concentrations of specific collagen fragments believed to discriminate between cathepsin K and MMP cleavage. Next, we provide evidence that MMPs are very critical for osteoclast migration, thereby controlling also the cell-matrix interactions required for cell attachment/detachment. The evidence supporting this role is based on a model of osteoclast recruitment in primitive long bones, an assay of osteoclast invasion through collagen gel, and the effect of proteinase inhibitors/knockouts in these models. Furthermore, we mention observations indicating a role of MMPs in initiation of bone resorption. Finally, we emphasize the many distinct ways MMPs may alter focally the extracellular environment thereby regulating the osteoclast behavior. Although the understanding of MMPs in osteoclast biology is rapidly expanding, it is suspected that important roles remain to be discovered.

Bone metabolic markers in bisphosphonate therapy for skeletal metastases in patients with breast cancer

The use of bisphosphonates for skeletal metastasis of breast cancer is now well established. Although clinical judgement for treating skeletal metastasis is based on symptoms and imaging studies, accurate or quantitative means are few. Various bone metabolic markers have been developed and these were evaluated in patients with metastasis to bone. Bone metabolic markers, especially resorption markers, have been shown to be a good tool for the monitoring the response to therapy for skeletal metastasis. This is also true for bisphosphonate treatment for skeletal metastasis. Bone metabolic markers are produced by different mechanisms. There are some different classes of resorption markers; tartrate-resistant acid phosphatase (TRAP) is secreted by osteoclast, N- and C-terminal cross-linking telopeptide of type I collagen (NTx and CTx) are the degradation the products of type I collagen, mainly produced by cathepsin K, and pyridinoline cross-linked carboxyl-terminal telopeptides of type I collagen (I CTP) is also a degradation product of type I collagen, by matrix metalloproteases. Even though bone resorption markers are a good tool to monitor response to bisphosphonate therapy, there remains the question of which class of bone resorption markers is best suited to the task.

Serum prolidase I activity and some bone metabolic markers in patients with breast cancer: in relation to menopausal status

OBJECTIVES

The purpose of this study was to investigate the diagnostic value of some osteoblastic/osteoclastic biochemical markers and serum prolidase I activity in breast cancer (BC).

DESIGN AND METHODS

Serum bone gla protein (BGP), prolidase I activity, urinary deoxypyridinoline (Dpy) and calcium excretions were measured, in metastatic and nonmetastatic BC patients, and in 52 healthy women.

RESULTS

In patients with metastases, bone turnover markers were found to be significantly higher than those in the control group and in patients without metastases. Serum prolidase activity in patients with and without metastases was also significantly higher than those in the control group, but there was no difference between the two patient groups.

CONCLUSIONS

Bone turnover has been suggested to be accelerated in BC patients with the more pronounced osteolytic activation, especially in metastatic state. Serum prolidase in premenopausal period appears to be valuable in discriminating cancer patients from controls. BGP and to a lesser degree of Dpy, may be useful markers for predicting the metastatic bone involvement, as well as for the more cost effective management of BC patients and monitoring the effects of antiresorptive therapy of malignant osteolysis before any metastasis could be detected by other invasive techniques.

The type I collagen fragments ICTP and CTX reveal distinct enzymatic pathways of bone collagen degradation

Bone resorption may generate collagen fragments such as ICTP and CTX, which can be quantified in serum and/or urine by using specific immunoassays, and which are used as clinical markers. However, the relative abundance of ICTP and CTX varies according to the type of bone pathology, suggesting that these two fragments are generated through distinct collagenolytic pathways. In this study, we analyzed the release of ICTP and CTX from bone collagen by the proteinases reported to play a role in the solubilization of bone matrix. Cathepsin K released large amounts of CTX, but did not allow a detectable release of ICTP. Conversely, the matrix metalloproteinases (MMPs) MMP-2, -9, -13, or -14 released ICTP, but did not allow a detectable release of CTX. Next we analyzed the release of ICTP and CTX from bone explants cultured in the presence of well-established inhibitors of these proteinases and of matrix solubilization. An inhibitor of cysteine proteinases including cathepsin K, inhibited the release of CTX, but not the release of ICTP. MMP inhibitors inhibited the release of ICTP, but also that of CTX, in agreement with the putative role of MMPs in the initiation of bone resorption in addition to matrix solubilization. Similarly the treatment of mice bearing bone metastasis with an MMP inhibitor led to a significant reduction of serum ICTP and CTX, and osteolytic lesions. We conclude that the generation of ICTP and CTX depends on different collagenolytic pathways. This finding may explain why these two markers may discriminate between different bone pathologies.

Bone markers in the management of patients with skeletal metastases

BACKGROUND

Biochemical markers of bone remodeling have been used as surrogate markers to manage patients with metastatic bone disease. Markers of the bone resorptive process, such as the bone collagen breakdown products N-telopeptide and C-telopeptide, are useful markers for monitoring the response and efficacy of antiresorptive therapy and to assess disease progression in patients with osteolytic bone disease. Recently discovered markers of osteoclastogenesis, osteoprotegerin (OPG) and the soluble form of the receptor activator for nuclear factor (NF)-kappaB (RANK-L), also are candidate markers of the bone metastases process and offer potential as surrogate markers of tumor-induced osteoclastogenesis.

METHODS

Immunoassays have been developed that can determine blood and urine levels of the telopeptides associated with bone collagen breakdown. In addition, immunoassays now are available that can measure both OPG and the soluble form of RANK-L in blood and tissues as markers of osteoclastogenesis.

RESULTS

The measurement of bone collagen breakdown products and specific factors associated with the process of osteoclastogenesis have been applied to the management and assessment of patients with metastatic bone disease. Results indicate that these surrogate markers can be useful in determining response to antiresorptive therapy, in selecting optimal dosage, and as markers of disease progression.

CONCLUSIONS

Although they show promise, questions remain whether blood measurements of surrogate markers of osteoclastogenesis, like OPG and RANK-L, will be useful in both assessing and managing patients with metastatic bone disease.

Elevated serum periostin levels in patients with bone metastases from breast but not lung cancer

Periostin is a recently identified gene that is preferentially expressed in periosteum, indicating a potential role in bone formation and maintenance of structure. We independently identified and isolated periostin from cancer tissue, using the palindromic PCR-driven cDNA Differential Display technique. For the present work, we developed a novel sandwich chemiluminescence assay to detect serum periostin level using newly developed monoclonal and polyclonal antibodies. We investigated serum periostin levels in breast cancer and small cell lung cancer patients, especially in patients with bone metastasis. The study included 58 breast cancer and 44 small cell lung cancer patients. Serum periostin levels were elevated in breast cancer patients presenting with bone metastases (92.0 +/- 28.6 ng/ml) compared to similar breast cancer patients without evidence of bone metastasis (55.0 +/- 16.6 ng/ml, p = 0.04). No correlation was found between the serum periostin level and any other prognostic factors, such as clinical stage and lymph node metastasis in breast cancer. Serum periostin levels thus appear to serve as a marker of bone metastasis from breast cancer. In contrast, serum periostin levels were similar in samples from patients with small cell lung cancer who did or did not have bone metastasis. However, increasing T-stage and N-stage of patients with small cell lung cancer were correlated with higher periostin levels (T4, 126.5 +/- 29.7 ng/ml v.s. T2, 64.9 +/- 16.1 ng/ml, p = 0.03; and T4 v.s. T1, 36.3+/- 7.5 ng/ml, p = 0.01; N3, 108.7 +/- 17.3 ng/ml v.s. N2, 49.7+/- 10.9 ng/ml, p = 0.01). Periostin has a substantial homology with the insect cell adhesion molecule, fasciclin I. Thus, expression of periostin may facilitate tumor cell adhesion to the bone surface. In fact, we found by in situ RNA hybridization, that the periostin gene was highly expressed in the stromal cells immediately surrounding the tumor, but not within the breast cancer cells themselves.

Monitoring of bone resorption and bone formation in multiple myeloma

The article deals with the clinical value of monitoring of serum markers of osteoresorption (ICTP) and bone formation (PICP) in multiple myeloma. In a group of patients treated by conventional chemotherapy and group of patients treated by high dose chemotherapy with autologous peripheral blood stemm cell transplantation (APBSTC).

Bone metabolic markers as gauges of metastasis to bone: a review

Currently, imaging techniques are the leading methods used to diagnose of metastasis to bone. However, these techniques are expensive, expose patients to toxic and radioactive compounds, and monitor response to treatment poorly; these drawbacks have prompted the search for alternative screening methods. Therefore, bone metabolic markers have been evaluated as possible methods to diagnose and monitor the development and progression of metastatic bone disease. Although bone metabolic markers are often grouped as either resorption or formation markers, studies have revealed that each marker has its own biologic meaning and clinical relevance. Recent milestones in the use of bone metabolic markers as screening methods for metastatic bone disease and as evaluation methods for treatment response are shown in the following lists. 1. Bone metabolic marker measurements provide insight into mechanisms of metastasis to bone. 2. Although promising data have been reported, bone metabolic markers are not yet considered to be reliable screening methods for metastasis to bone. 3. Bone metabolic markers are reliable indicators of response to both conventional and bisphosphonate therapies. 4. Preliminary results indicate bone metabolic markers might be an independent prognostic factor in patients whose tumors metastasize to bone. 5. New or refined assays for bone metabolic markers are expected to improve the sensitivity and specificity of bone metabolic marker use in diagnosing and monitoring metastasis to bone.

Assessment of response to systemic therapy focusing on metastatic bone disease

The 25-year-old rules for response evaluation developed by UICC and WHO still remain the cornerstone for response evaluation and documentation of treatment effects from systemic cancer treatment. Often, however, plain radiographs are insensitive to changes in tumour growth and disagree with clinical findings. Other methods of evaluation, such as biochemical markers and newer imaging technology may provide valuable additional information in these cases.

Biochemical markers and skeletal metastases

BACKGROUND

Skeletal metastases are common occurrences in patients with malignancies such as breast and prostate carcinoma, but they are difficult to diagnose nonradiologically, and treatment is difficult to follow clinically. Recent developments suggest that biochemical markers of bone remodeling, such as the bone collagen breakdown product N-telopeptide and the bone formation marker known as bone specific alkaline phosphatase, hold great promise as clinical tools for the management of patients with metastatic bone disease.

METHODS

Serum levels of the bone formation marker known as bone specific alkaline phosphatase (BAP), along with serum levels of the bone collagen breakdown product carboxyterminal telopeptide of Type I collagen (ICTP) and urine levels of pyridinoline (PYD), deoxypridinoline (DPD), and N-telopeptide (NTx), were measured in a large cohort of patients with newly diagnosed or progressive cancer of the breast, prostate, lung, and other sites. Bone marker levels were correlated with the presence or absence of bone scan-documented metastases; metastatic disease extension in terms of the number of skeletal sites involved; and the type of lesion, whether blastic or lytic. Sites examined included the pelvis, spine, skull, ribs, and long bones.

RESULTS

All of the bone markers examined, including BAP and NTx, were abnormally elevated in a high proportion of patients with confirmed metastases to bone. Urine NTx levels and bone specific alkaline phosphatase were significantly correlated with the number of skeletal sites involved, and a significant correlation between marker level and extent of skeletal involvement was also observed. In addition, both markers were higher in patients with a blastic disease presentation than in patients with osteolytic lesions.

CONCLUSIONS

Biochemical markers of bone resorption and bone formation are abnormally raised in the blood and urine of patients with metastatic bone disease. Markers of bone collagen breakdown, such as N-telopeptide, as well as markers of osteoblast function, such as bone specific alkaline phosphatase, appear to be of use in assessing and managing patients with malignancies that metastasize to bone. In this study, both NTx and BAP showed a significant correlation with both the presence of bone metastases and the extent of skeletal involvement. Biochemical markers of bone remodeling can also be used to guide decision making regarding the treatment of metastatic bone disease and to determine the effectiveness of therapy for patients with cancer to bone whose broad-based symptoms make it difficult to discern true response to therapy.

Tumour marker measurements in the diagnosis and monitoring of breast cancer

Elevation of established blood tumour markers correlates with the stage of breast cancer. The major role of current blood markers is therefore in the diagnosis and monitoring of metastatic disease. A combination of markers is better than a single marker with the most widely adopted combination being CEA and one MUC1 mucin, commonly detected as either CA15.3 or CA27.29. Tumour marker measurement is now used as a complementary test in the diagnosis of symptomatic metastases. In the monitoring of therapeutic response to both endocrine and cytotoxic therapies in advanced disease, biochemical assessment using blood markers not only correlates with conventional UICC criteria but has a lot of advantages which make it a potentially superior way of assessment. In this regard, CA15.3, CEA and ESR are the best validated combination. Studies are ongoing to evaluate the use of sequential blood tumour marker measurements in the follow-up of patients after treatment for their primary breast cancer, in terms of both early detection and early therapeutic intervention. Further randomized studies are also required to ascertain that marker-directed therapy is superior to the current practice for metastatic disease. In line with clinical studies, intensive laboratory work is being carried out to optimize the use of blood markers in advanced disease as well as to exploit their use in screening and diagnosis of early primary breast cancer.

Bone metastasis after a resection of stage I and II primary lung cancer

In the present study, we reviewed the patients who developed bone metastases after a surgical resection of primary lung cancer and evaluated their clinicopathological features. From 1992 to 1995, 177 patients with stage I and II primary lung cancer underwent a surgical resection at the Kitakyushu Municipal Medical Center. Bone metastases were detected in 14 patients (7.9%) by follow-up examinations including bone scintigraphy (scan). Bone metastasis was one of the most frequent extra-thoracic recurrent forms. Patients with adenocarcinoma tended to develop bone metastases more frequently than those with squamous cell carcinoma. In the preoperative bone scans, an abnormal uptake was observed in 76 patients (42.9%), and 10 (13.1%) of them were found to develop bone metastases in the follow-up studies. A microscopic examination of the primary tumor demonstrated close correlation between intratumoral and peritumoral lymphatic vessel invasion and postoperative development of bone metastases. A bone scan is a very useful and indispensable procedure for diagnosing bone metastases. However, this scan may also show false positive finding in a number of benign conditions. Therefore, a surgical resection should be considered as the first-line treatment for patients with positive findings in the bone scan when the diagnosis of bone metastasis can not be confirmed based on both their symptoms and other clinical examinations.

Assessment of bone response to systemic therapy in an EORTC trial: preliminary experience with the use of collagen cross-link excretion. European Organization for Research and Treatment of Cancer

This study was designed to evaluate new bone resorption and tumour markers as possible alternatives to serial plain radiographs for the assessment of response to treatment. Thirty-seven patients with newly diagnosed bone metastases from breast cancer, randomized to receive oral pamidronate or placebo tablets in addition to anticancer treatment within the context of a multicentre EORTC trial, who were both assessable for radiographic response in bone and had serum and urine samples collected for more than 1 month were studied. The markers of bone metabolism measured included urinary calcium (uCa), hydroxyproline (hyp), the N-telopeptide cross-links of type I collagen (NTx) and total alkaline phosphatase. The tumour markers measured were CA15-3 and cancer-associated serum antigen (CASA). Before treatment, levels of Ntx, uCa and Hyp were elevated in 41%, 24% and 28% respectively, and CA15-3 and CASA increased in 69% and 50%. For assessment of response and identification of progression, Ntx was the most useful bone marker. All markers behaved similarly in no change (NC) and partial response (PR) patients. There was a significant difference (P < or = 0.05) in Ntx levels (compared to baseline) at 1 and 4 months and in CA15-3/CASA at 4 months between patients with PR or NC and those with progressive disease (PD), and at 4 months between those with time to progression (TP) > 7 and those with TP < or = 7 months. The diagnostic efficiency (DE) for prediction of PD following a > 50% increase in Ntx or CA15-3 was 78% and 62% respectively. An algorithm to predict response to therapy has been developed for future prospective evaluation.

Bone metabolic markers in the evaluation of bone scan flare phenomenon in bone metastases of breast cancer

Bone scan flare seriously complicates evaluations of the therapeutic response of bone metastases. The value of bone metabolic markers in monitoring the therapeutic response for bone metastases in breast cancer was assessed. Twenty-three breast cancer patients with bone metastases treated by combined chemotherapy of cyclophosphamide, doxorubicin, and 5-fluorouracil (CAF) were monitored using bone scans; a bone resorption marker, pyridinoline cross-linked carboxy-terminal telopeptide of type I collagen (ICTP); a bone formation marker, bone-specific alkaline phosphatase (BAI-p); and a tumor-specific marker (CA15-3). Bone scans were performed before and 3 or 4 months after therapy. After CAF therapy, markers were measured monthly. As a control, the markers of nine patients without bone metastases who received adjuvant CAF therapy were also measured monthly. The therapeutic effect on bone metastases was assessed after the study. Five patients had progression of disease (PD), three had no change (NC), and 15 patients had partial responses (PR). Bone scan flare-up was seen in five PR patients. In patients who received adjuvant therapy, ICTP, BAI-p, and CA15-3 did not change. ICTP increased significantly in PD patients. ICTP did not increase in either NC or PR, including bone scan flare patients. BAI-p and CA15-3 did not show any discernible pattern among PD, PR, flare, and NC patients. Thus measuring ICTP could distinguish PD from NC or PR patients' responses to CAF therapy. This was true also for patients who showed bone scan flare-up. Measuring a bone resorption marker, ICTP, allows clinicians to monitor patients' responses to CAF therapy and may prevent prolonged ineffective therapy or unnecessary changes in therapy as a result of the flare phenomenon.

Biochemical markers of bone turnover in breast cancer patients with bone metastases: a preliminary report

BACKGROUND

Some biochemical markers of bone turnover are expected to reflect the disease activity of metastatic bone tumor. In the present study six biochemical markers were evaluated to determine appropriate markers for the detection of metastatic bone tumors from breast cancer (BC).

METHODS

A panel of bone turnover markers was assessed in 11 normocalcemic patients with bone metastases from BC and in 19 BC patients without clinical evidence of bone metastases. Bone formation was investigated by measuring serum bone isoenzyme of alkaline phosphatase (BALP), osteocalcin (OC) and carboxy-terminal propeptide of type I procollagen (PICP): Bone resorption was investigated by measuring serum carboxy-terminal telopeptide of type I collagen (ICTP), fasting urinary pyridinoline (Pyr) and deoxypyridinoline (D-Pyr).

RESULTS

PICP was influenced by age and menopausal status. Significant correlations were observed between each of bone turnover markers except between BALP and OC. The mean levels of the six bone turnover markers were higher in patients with bone metastases than in those without them and significance was observed except for OC. The best diagnostic efficiency by receiver-operating characteristic (ROC) analysis was provided by ICTP followed by Pyr or D-Pyr, BALP, PICP and OC and significance was observed between ICTP and OC. Multiple logistic regression analysis adjusted by age revealed that the only significant marker related to bone metastases was ICTP.

CONCLUSIONS

Serum ICTP appears to be the leading marker of bone metastases from BC. However, to reveal the clinical usefulness of these markers, further examination will be needed to account for the ease and cost-effectiveness of the measurements.

Usefulness of bone metabolic markers in the diagnosis and follow-up of bone metastasis from lung cancer

Ninety-one lung cancer patients were evaluated to determine the usefulness of bone metabolic markers in the diagnosis and follow-up of bone metastases and also to investigate their clinical usefulness as an adjunct to bone scintigraphy. Both bone resorption markers, ICTP and fDPD, and bone formation markers, Al-p, BAL, PICP and BGP, were evaluated in 47 patients with and 44 without bone metastasis. The patients with bone metastasis were classified according to the bone metastatic burden, and they were also separately classified into groups according to the course of the bone metastasis. ICTP, fDPD, Al-p and BAL were significantly elevated (P < 0.001) in patients with bone metastasis, but PICP and BGP were not. Receiver-operating characteristic (ROC) curves of these markers revealed that ICTP was most highly correlated with the diagnosis of bone metastasis. The sensitivity of ICTP (71.4%) and fDPD (61.0%) were good with high specificity. T scores of ICTP, fDPD and BAL tended to be higher at higher grades of bone metastasis. T-scores of ICTP, fDPD and BAL were elevated in the newly diagnosed cases and progressed cases, but the T-scores of ICTP and fDPD in those cases were higher than that of BAL. In the follow-up study, ICTP was well correlated with uncontrolled or controlled bone metastasis. Thus, bone resorption markers, especially ICTP, could be a good indicator of the progression and multiplicity of disease, and it could help in the follow-up and in the monitoring of therapy for bone metastasis from lung cancer.