Serum glycoproteins in cancer patients: first report of correlations with in vitro and in vivo parameters of cellular immunity

Evaluation of serum sialic acid, fucose levels and their ratio in oral squamous cell carcinoma

Background:

Detection of cancer at the early stage is of utmost importance to decrease the morbidity and mortality of the disease. Apart from the conventional biopsy, minimally invasive methods like serum evaluation are used for screening large populations. Thus, this study aimed to estimate serum levels of sialic acid and fucose and their ratio in oral cancer patients and in healthy control group to evaluate their role in diagnosis.

Materials and Methods:

Serum samples were collected from 52 healthy controls (group I) and 52 squamous cell carcinoma patients (group II). Estimation of serum levels of sialic acid and fucose and their ratio was performed. This was correlated histopathologically with the grades of carcinoma. Statistical analysis was done by using analysis of variance (ANOVA) test and unpaired “t” test.

Results:

Results showed that serum levels of sialic acid and fucose were significantly higher in oral cancer patients compared to normal healthy controls (P < 0.001). The sialic acid to fucose ratio was significantly lower in cancer patients than in normal controls (P < 0.01). However, comparison with histological grading, habits, gender, and age group did not show any significant result.

Conclusion:

The mean serum sialic acid and fucose levels showed an increasing trend from controls to malignant group and their corresponding ratio showed decreasing trend from controls to malignant group. The ratio of sialic acid to fucose can be a useful diagnostic aid for oral cancer patients.

Cancer serum biomarkers based on aberrant post-translational modifications of glycoproteins: Clinical value and discovery strategies

Due to the increase in life expectancy in the last decades, as well as changes in lifestyle, cancer has become one of the most common diseases both in developed and developing countries. Early detection remains the most promising approach to improve long-term survival of cancer patients and this may be achieved by efficient screening of biomarkers in biological fluids. Great efforts have been made to identify specific alterations during oncogenesis. Changes at the cellular glycosylation profiles are among such alterations. The "glycosylation machinery" of cells is affected by malignant transformation due to the altered expression of glycogens, leading to changes in glycan biosynthesis and diversity. Alterations in the post-translational modifications of proteins that occur in cancer result in the expression of antigenically distinct glycoproteins. Therefore, these aberrant and cancer-specific glycoproteins and the autoantibodies that are produced in response to their presence constitute targets for cancer biomarkers' search. Different strategies have been implemented for the discovery of cancer glycobiomarkers and are herein reviewed, along with their potentialities and limitations. Practical issues related with serum analysis are also addressed, as well as the challenges that this area faces in the near future.

The use of infrared thermography as a rapid, quantitative, and noninvasive method for evaluation of inflammation response in different anatomical regions of rats

PURPOSE

Thermographic assessment of temperature distribution within the examined tissues allows a quick, noncontact, noninvasive measurement of their temperature. The aim of the study was to evaluate the usefulness of digital infrared imaging in monitoring experimental inflammation of pleura (PL), lower lip (LL), and left paw (LP) and right paw (RP) of lower limbs in rats.

MATERIALS AND METHODS

The inflammatory reaction was induced by injection of 1% carrageenin solution into pleural cavity, lip, or paws. With the use of digital infrared imaging temperature measurement was conducted at 0 to 72 hours of the inflammatory reaction.

RESULTS

The temperature decrease was observed at the site of injection directly afterwards. Next, it was gradually increasing and it reached the maximum on the third day of the inflammatory reaction. Statistically significant changes were observed after 48-hour period in PL and LL regions, as well as after 72-hour period in LP and RP regions (P < 0.005).

CONCLUSION

It was found that thermographic examination allows for indicating the presence of inflammatory reaction within examined tissues and determining the dynamics of this process. This method could be used as alternative procedure that allows using fewer animals for experiments.

Serum levels of BMP-2, 4, 7 and AHSG in patients with degenerative joint disease requiring total arthroplasty of the hip and temporomandibular joints

To date, there is no objective or reliable means of assessing the severity of degenerative joint disease (DJD) and need for joint replacement surgery. Hence, it is difficult to know when an individual with DJD has reached a point where total arthroplasty is indicated. The purpose of the present study is to determine whether serum levels of Alpha-2 HS-glycoprotein (AHSG) as well as bone morphogenetic proteins (BMP-2, 4, 7) can be used to predict the presence of severe DJD of the hip and/or temporomandibular joint (TMJ) (specifically: joints that require replacement). A total of 30 patients scheduled for arthroplasty (diseased) (15 HIP, 15 TMJ) and 120 age-matched controls (healthy/non-diseased) were included. Blood samples were collected from all patients ≥8 weeks after the last arthroplasty. Concentrations of serum analytes were measured using enzyme-linked immunosorbent assays, and these were compared between the Diseased and Healthy groups, utilizing the Mann-Whitney U-test. Patients with disease had significantly higher levels of BMP-2 and BMP-4 and lower levels of AHSG in serum compared to non-diseased humans (p < 0.01). Higher levels of BMP-2, 4 and reduced levels of AHSG appear to characterize patients who have DJD that is severe enough to require total joint replacement. Perhaps measurements of these proteins can be used to make objective decisions regarding the need for total arthroplasty as opposed to the current subjective approaches.

Glycoprotein electrophoretic patterns have potential to monitor changes associated with neoplastic transformation in oral cancer

Alterations in glycoproteins, important cell surface constituents, have long been associated with various malignancies. The present investigation therefore explored the clinical significance of a glycoproteomics approach in patients with oral precancerous conditions (OPC) and patients with oral cancer. The study included 80 oral cancer patients, 50 patients with OPC, and 84 controls. Native polyacrylamide gel electrophoresis followed by Schiff’s staining was carried out to study the alterations in glycoproteins. The results showed significant elevation (p<0.0001) of 192 kDa, 170 kDa, 116 kDa and 44 kDa glycoproteins in oral cancer patients and patients with OPC compared with controls. The odds ratio indicated a significantly higher risk for oral cancer among users and especially chewers of tobacco. The levels of all the glycoprotein bands (192 kDa, 170 kDa, 116 kDa and 44 kDa) were higher in patients with a habit of tobacco use (WHT) than in patients with no habit of tobacco (NHT) and were also higher in WHT controls than in NHT controls. Moreover, a 230 kDa glycoprotein consistently appeared only in individuals with tobacco habits and an increasing trend was observed from WHT controls to patients with OPC to WHT oral cancer patients. In conclusion, the results indicated the potential utility of glycoprotein alterations in monitoring sequential changes occurring due to tobacco consumption during neoplastic transformation.

Extracellular chaperones

The maintenance of the levels and correct folding state of proteins (proteostasis) is a fundamental prerequisite for life. Life has evolved complex mechanisms to maintain proteostasis and many of these that operate inside cells are now well understood. The same cannot yet be said of corresponding processes in extracellular fluids of the human body, where inappropriate protein aggregation is known to underpin many serious diseases such as Alzheimer's disease, type II diabetes and prion diseases. Recent research has uncovered a growing family of abundant extracellular chaperones in body fluids which appear to selectively bind to exposed regions of hydrophobicity on misfolded proteins to inhibit their toxicity and prevent them from aggregating to form insoluble deposits. These extracellular chaperones are also implicated in clearing the soluble, stabilized misfolded proteins from body fluids via receptor-mediated endocytosis for subsequent lysosomal degradation. Recent work also raises the possibility that extracellular chaperones may play roles in modulating the immune response. Future work will better define the in vivo functions of extracellular chaperones in proteostasis and immunology and pave the way for the development of new treatments for serious diseases.

Extracellular Chaperones

The maintenance of the levels and correct folding state of proteins (proteostasis) is a fundamental prerequisite for life. Life has evolved complex mechanisms to maintain proteostasis and many of these that operate inside cells are now well understood. The same cannot yet be said of corresponding processes in extracellular fluids of the human body, where inappropriate protein aggregation is known to underpin many serious diseases such as Alzheimer's disease, type II diabetes and prion diseases. Recent research has uncovered a growing family of abundant extracellular chaperones in body fluids which appear to selectively bind to exposed regions of hydrophobicity on misfolded proteins to inhibit their toxicity and prevent them from aggregating to form insoluble deposits. These extracellular chaperones are also implicated in clearing the soluble, stabilized misfolded proteins from body fluids via receptor-mediated endocytosis for subsequent lysosomal degradation. Recent work also raises the possibility that extracellular chaperones may play roles in modulating the immune response. Future work will better define the in vivo functions of extracellular chaperones in proteostasis and immunology and pave the way for the development of new treatments for serious diseases.

Chapter 6: The chaperone action of Clusterin and its putative role in quality control of extracellular protein folding

The function(s) of clusterin may depend upon its topological location. A variety of intracellular "isoforms" of clusterin have been reported but further work is required to better define their identity. The secreted form of clusterin has a potent ability to inhibit both amorphous and amyloid protein aggregation. In the case of amorphous protein aggregation, clusterin forms stable, soluble high-molecular-weight complexes with misfolded client proteins. Clusterin expression is increased during many types of physiological and pathological stresses and is thought to function as an extracellular chaperone (EC). The pathology of a variety of serious human diseases is thought to arise as a consequence of the inappropriate aggregation of specific extracellular proteins (e.g., Abeta peptide in Alzheimer's disease and beta(2)-microglobulin in dialysis-related amyloidosis). We have proposed that together with other abundant ECs (e.g., haptoglobin and alpha(2)-macroglobulin), clusterin forms part of a previously unknown quality-control (QC) system for protein folding that mediates the recognition and disposal of extracellular misfolded proteins via receptor-mediated endocytosis and lysosomal degradation. Characterizing the mechanisms of this extracellular QC system will thus have major implications for our understanding of diseases of this type and may eventually lead to the development of new therapies.

Profiling of serum and tissue high abundance acute-phase proteins of patients with epithelial and germ line ovarian carcinoma

Background

Acute-phase response involves the simultaneous altered expression of serum proteins in association to inflammation, infection, injury or malignancy. Studies of the acute-phase response usually involve determination of the levels of individual acute-phase serum proteins. In the present study, the acute-phase response of patients with epithelial (EOCa) and germ-line (GOCa) ovarian carcinoma was investigated using the gel-based proteomic approach, a technique which allowed the simultaneous assessment of the levels of the acute-phase serum high abundance proteins. Data obtained were validated using ELISA and immunostaining of biopsy samples.

Results

Enhanced expression of clusterin (CLU), α₁-antitrypsin, haptoglobin and leucine rich glycoprotein was detected in all patients. However, the levels of α₁-antichymotrypsin (ACT) was only enhanced in EOCa patients, while patients with GOCa were typically characterized by elevated levels of ceruloplasmin but lower levels of α₂-HS glycoprotein. The enhanced expression of CLU in EOCa and GOCa patients and up-regulated expression of ACT specifically in EOCa patients were confirmed by ELISA. Immunohistochemical staining of biopsy samples of EOCa and GOCa patients demonstrated correlation of the acute-phase protein expression.

Conclusion

Patients with EOCa and GOCa demonstrated distinctive aberrant expression of serum and tissue high abundance acute-phase proteins compared to negative control women.

Vascular calcification inhibitors in relation to cardiovascular disease with special emphasis on fetuin-A in chronic kidney disease

The mortality rate is extremely high in chronic kidney disease (CKD), primarily due to the high prevalence of cardiovascular disease (CVD) in this patient group. Apart from traditional Framingham risk factors, evidences suggest that nontraditional risk factors, such as inflammation, oxidative stress, endothelial dysfunction, and vascular calcification also contribute to this extremely high risk of CVD. Disturbance in the mineral metabolism, especially in the ions of Ca and PO4, are linked to enhanced calcification of blood vessels. Although the mechanism(s) of this enhanced calcification process are not fully understood, current knowledge suggests that a large number (and an imbalance between them) of circulating promoters and inhibitors of the calcification process, that is, fetuin-A (or alpha 2-Heremans-Schmid glycoprotein, AHSG), matrix-Gla protein (MGP), osteoprotegerin (OPG), osteopontin (OPN), bone morphogenetic proteins (BMPs), and inorganic pyrophosphate (PPi), are involved in the deterioration of vascular tissue. Thus, an imbalance in these factors may contribute to the high prevalence of vascular complications in CKD patients. Among these mediators, studies on fetuin-A deserve further attention as clinical studies consistently show that fetuin-A deficiency is associated with vascular calcification, all-cause and cardiovascular mortality in CKD patients. Both chronic inflammation and the uremic milieu per se may contribute to fetuin-A depletion, as well as specific mutations in the AHSG gene. Recent experimental and clinical studies also suggest an intriguing link between fetuin-A, insulin resistance, and the metabolic syndrome.

Vascular calcification and uremia: what do we know?

In the last decade, the nephrology community has focused its attention on the main cause of morbidity and mortality in chronic renal failure patients: cardiovascular disease. In addition, recent studies pointed out that vascular calcification (VC) is a major cause of cardiovascular disease in the dialysis population. Interestingly, the pathogenesis of VC and soft tissue calcification in chronic kidney disease (CKD) has been extensively investigated. Nowadays we know that VC is associated not only with passive calcium phosphate deposition, but also with an active, cell-mediated process. To better understand the pathogenesis of VC in CKD, numerous regulatory proteins have been studied, because of their ability to inhibit mineral deposition in the vessels. We here examine the state of the art of those substances recognized as regulatory key factors in preventing VC in uremic conditions, such as fetuin A (alpha2-Heremans-Schmid glycoprotein), matrix gamma-carboxyglutamic acid protein, pyrophosphate, osteoprotegerin and bone morphogenetic protein. We conclude that at present it is too early to introduce these novel markers into clinical practice.

Pathogenesis of vascular calcification in chronic kidney disease

Pathogenesis of vascular calcification in chronic kidney disease. Background. Hyperphosphatemia and hypercalcemia are independent risk factors for higher incidence of cardiovascular events in patients with chronic kidney disease. In addition to increased calcium-phosphate product, hyperphosphatemia accelerates the progression of secondary hyperparathyroidism with the concomitant bone loss, possibly linked to vascular calcium-phosphate precipitation. Results. The control of serum phosphate levels reduces vascular calcification not only by decreasing the degree of secondary hyperparathyroidism and calcium-phosphate product, but also by reducing the expression of proteins responsible for active bone mineral deposition in cells of the vasculature. The calcium and aluminum-free phosphate-binders provide a new and effective therapeutic tool in preventing vascular calcifications in chronic kidney disease in animal models and in hemodialysis patients. Conclusion. Additional investigations are necessary to examine the benefits of different phosphate-binders in reducing mortality from cardiovascular disease.

The Serum Glycoprotein Fetuin-A Promotes Lewis Lung Carcinoma Tumorigenesis via Adhesive-Dependent and Adhesive-Independent Mechanisms

Fetuin-A is a serum glycoprotein in the cystatin family associated with the regulation of soft tissue calcification. We tested the role of systemic fetuin in tumor cell growth and metastasis by injecting Lewis lung carcinoma (LLC) cells into fetuin-A null and their wild-type (WT) littermate control C57BL/6 mice via the tail vein, s.c., and intrasplenic routes. In the experimental metastasis assay, the lungs of the WT mice were filled with metastatic nodules, whereas the lungs of the fetuin-A null mutant mice were virtually free of colonies at the end of 2 weeks. Lung colonization responded to the levels of serum fetuin-A in a dose-dependent manner, as observed by the formation of half as many colonies in mice heterozygous for the fetuin-A locus compared with homozygous WT mice and restoration of lung colonization by the administration of purified fetuin-A to fetuin-A-null mice. Serum fetuin-A also influenced the growth of LLC cells injected s.c.: fetuin-A-null mice developed small s.c. tumors only after a substantial delay. Similarly, intrasplenic injection of LLC cells resulted in rapid colonization of the liver with metastasis to the lungs within 2 weeks in the WT but not fetuin-A null mice. To examine the mechanism by which fetuin-A influences LLC colonization and growth, we showed that LLC tumor cells adhere to fetuin-A in a Ca2+-dependent fashion, resulting in growth of the tumor cells. These studies support the role of fetuin-A as a major growth promoter in serum that can influence tumor establishment and growth.

α2HS-glycoprotein, an Antagonist of Transforming Growth Factor β In vivo, Inhibits Intestinal Tumor Progression

Transforming growth factor (TGF)-beta1 is associated with tumor progression and resistance to chemotherapy in established cancers, as well as host immune suppression. Here, we show that the serum glycoprotein alpha2-HS-glycoprotein (AHSG) blocks TGF-beta1 binding to cell surface receptors, suppresses TGF-beta signal transduction, and inhibits TGF-beta-induced epithelial-mesenchymal transition, suggesting that AHSG may play a role in tumor progression. In 66 consecutive sporadic human colorectal cancer specimens, we observed a 3-fold depletion of ASHG in tumor compared with normal tissue, whereas levels of other abundant plasma proteins, albumin and transferrin, were equivalent. Using the Multiple intestinal neoplasia/+ (Min/+) mouse model of intestinal tumorigenesis, we found twice as many intestinal polyps overall, twice as many large polyps (>3 mm diameter), and more progression to invasive adenocarcinoma in Min/+ Ahsg-/- mice than in littermates expressing Ahsg. Phosphorylated Smad2 was more abundant in the intestinal mucosa and tumors of Min/+ mice lacking Ahsg, demonstrating increased TGF-beta signaling in vivo. Furthermore, TGF-beta-mediated suppression of immune cell function was exaggerated in Ahsg-/- animals, as shown by inhibition of macrophage activation and reduction in 12-O-tetradecanoylphorbol 13-acetate-induced cutaneous inflammation. Reconstitution of Ahsg-/- mice with bovine Ahsg suppressed endogenous TGF-beta-dependent signaling to wild-type levels, suggesting that therapeutic enhancement of AHSG levels may benefit patients whose tumors are driven by TGF-beta.

The serum protein alpha 2-Heremans-Schmid glycoprotein/fetuin-A is a systemically acting inhibitor of ectopic calcification

Ectopic calcification is a frequent complication of many degenerative diseases. Here we identify the serum protein alpha2-Heremans-Schmid glycoprotein (Ahsg, also known as fetuin-A) as an important inhibitor of ectopic calcification acting on the systemic level. Ahsg-deficient mice are phenotypically normal, but develop severe calcification of various organs on a mineral and vitamin D-rich diet and on a normal diet when the deficiency is combined with a DBA/2 genetic background. This phenotype is not associated with apparent changes in calcium and phosphate homeostasis, but with a decreased inhibitory activity of the Ahsg-deficient extracellular fluid on mineral formation. The same underlying principle may contribute to many calcifying disorders including calciphylaxis, a syndrome of severe systemic calcification in patients with chronic renal failure. Taken together, our data demonstrate a critical role of Ahsg as an inhibitor of unwanted mineralization and provide a novel therapeutic concept to prevent ectopic calcification accompanying various diseases.

Toward a high-throughput approach to quantitative proteomic analysis: expression-dependent protein identification by mass spectrometry

The isotope-coded affinity tag (ICAT) technology enables the concurrent identification and comparative quantitative analysis of proteins present in biological samples such as cell and tissue extracts and biological fluids by mass spectrometry. The initial implementation of this technology was based on microcapillary chromatography coupled on-line with electrospray ionization tandem mass spectrometry. This implementation lacked the ability to select proteins for identification based on their relative abundance and therefore to focus on differentially expressed proteins. In order to improve the sample throughput of this technology, we have developed a two-step approach that is focused on those proteins for which the abundance changes between samples: First, a new software program for the automated quantification of ICAT reagent labeled peptides analyzed by microcapillary electrospray ionization time-of-flight mass spectrometry determines those peptides that differ in their abundance and second, these peptides are identified by tandem mass spectrometry using an electrospray quadrupole time-of flight mass spectrometer and sequence database searching. Results from the application of this approach to the analysis of differentially expressed proteins secreted from nontumorigenic human prostate epithelial cells and metastatic cancerous human prostate epithelial cells are shown.

Fetuin in human bone marrow: detection in foetal tissue and patients with mastocytosis

Fetuin, a foetal protein of unknown function, has been shown to be expressed in both the immune and nervous systems, especially during development. Here, we show for the first time, that fetuin is abundantly present in many cells of the foetal human bone marrow, but is restricted to cells of the monocytic lineage in the adult. Fetuin's immunoreactivity increased considerably in adult human bone marrow in some pathological conditions, particularly in mastocytosis and was also increased in bone marrows in some cases of acute leukaemias, especially in acute myeloid leukaemia. This increase in the presence of fetuin in neoplastic bone marrows is not reflected by an increased level of circulating fetuin. This last observation contradicts earlier suggestions that fetuin is specifically reduced in cancer patients. A consistent increase in fetuin immunoreactivity in bone marrow of most cases of mastocytosis, as demonstrated in this paper, could become a useful tool in the diagnosis of this disease.

Dynamic surface tension and surface rheology of biological liquids

The paper presents results of dynamic and equilibrium surface tension measurements (using a maximum bubble pressure instrument) of serum and urine samples that were obtained from 80 healthy human of various sexes and ages. These data were compared with surface tension measurements of biological liquids obtained from patients suffering from malignant neoplasm of corpus uteri (n=5) and cervix uteri (n=31). In addition, surface dilatational rheology was determined on 32 samples using a drop shape method. The dilatational rheology data were compared with the dynamic surface tension data. Although some trends were found, no significant correlations exist between surface tension and rheology data and any of the disease states or stages. It is difficult to explain these findings in the framework of known mechanisms. However, our studies demonstrate that dynamic interface tensiometry of human biological liquids provide new insight into the biophysical behavior of these liquids, most likely reflecting compositional changes of them during ageing, the course of cancer and as a consequence of therapeutical interventions.

Regulation of human monocyte proMMP-9 production by fetuin, an endogenous TGF-beta antagonist

Members of the matrix metalloproteinase family of enzymes degrade specific components of the extracellular matrix. MMP-9 is a type IV/V collagenase necessary for normal osteogenesis and is increased in inflammatory and neoplastic conditions. In such destructive diseases as emphysema and arthritis, and in epithelial cancers, MMP-9 is produced by cells of the monocyte lineage. Fetuin, a prominent serum glycoprotein, binds to and inactivates TGF-beta family members and through this mechanism regulates osteogenesis (Binkert et al., 1999, J Biol Chem 274:28514-28520.). We studied the effects of TGF-beta1 and fetuin on proMMP-9 release by the human monocyte line THP-1. Exogenous TGF-beta1 stimulated proMMP-9 release by THP-1 cells, with half-maximal stimulation at approximately 0.01 ng/ml TGF-beta1. Human fetuin (0.5-2 microM) partially inhibited this stimulation. Human fetuin alone stimulated THP-1 monocyte proMMP-9 release, with half maximal stimulation at approximately 0.25 microM fetuin. Neutralizing antibody specific for TGF-beta1 also stimulated proMMP-9 release, suggesting that endogenously-derived TGF-beta1 has an inhibitory effect. In freshly isolated human peripheral blood monocytes, fetuin stimulated proMMP-9 release with a dose-response curve similar to that observed in THP-1 cells. Human fetuin also activated proMMP-9 present in THP-1 conditioned medium. Taken together, these data suggest that under physiological conditions, fetuin facilitates matrix degradation by monocyte-derived MMP-9, both by opposing the autocrine inhibitory effect of endogenous TGF-beta1 on proMMP-9 release, and by activating proMMP-9 in the pericellular milieu. Conversely, fetuin may limit the stimulation of monocyte proMMP-9 release by high levels of exogenous TGF-beta1. Such modulation could prove important under pathological conditions where TGF-beta1 derived from paracrine sources is abundant, such as in epithelial malignancies.

Pulmonary expression of the human haptoglobin gene

Haptoglobin (Hp), a member of the acute-phase reactants, has long been known as a major hemoglobin-binding protein associated with hemoglobin catabolism. Recent studies indicate that another important biologic function of Hp is the modulation of the immune response. We found that Hp is expressed at high levels in specific cells, including alveolar macrophages and eosinophils in diseased or inflamed human lung tissues, but not in the normal lung. Expression of the human Hp gene was studied in two transgenic mouse lines carrying a 9-kb human Hp 2 gene. In both lines, the human Hp transgene was expressed constitutively in alveolar macrophages at a high level, whereas the endogenous mouse Hp was synthesized in airway epithelial cells. Expression of the human Hp transgene in lung cells was upregulated when the transgenic mice were treated with endotoxin. In humans and in Hp transgenic mice, human Hp messenger RNA was also detected in circulating eosinophils, but not in other blood cells. Our findings suggest that Hp is involved in a variety of lung inflammatory diseases, including respiratory allergy and asthma. The transgenic mouse line that overexpresses the human Hp gene in alveolar macrophages and eosinophils is a promising system for investigating the function of Hp in vivo during lung inflammation.

Studies on the application of dynamic surface tensiometry of serum and cerebrospinal liquid for diagnostics and monitoring of treatment in patients who have rheumatic, neurological or oncological diseases

Human biological liquids comprise various surfactants, which adsorb at liquid interfaces and lead to a variation in surface tension. The adsorption processes involving low molecular weight surfactants, proteins and phospholipids play a vital role in the physiological functions of the human organism, especially if large surfaces are involved (e.g., gas exchange in lungs, metabolism of kidneys, liver and brain). Dynamic surface tensiometric studies of biological liquids like serum and cerebrospinal fluid provide surrogate parameters that reflect surface tension phenomena. We provide dynamic surface tension data of serum and cerebrospinal fluid that were collected from healthy volunteers and patients with rheumatic, neurological or oncological diseases. Our studies indicate that dynamic surface tension data are helpful for diagnostic purposes and for monitoring of therapeutic interventions.

Regulation of osteogenesis by fetuin

Osteoporosis is a common problem of aging and results from a failure of homeostatic mechanisms to regulate osteogenesis and mineralization. Bovine and human forms of fetuin glycoprotein bind to the transforming growth factor (TGF)-beta/BMP (bone morphogenic protein) cytokines and block their osteogenic activity in cell culture assays (Demetriou, M., Binkert, C., Sukhu, B., Tenenbaum, H. C., and Dennis, J. W. (1996) J. Biol. Chem. 271, 12755-12761). Fetuin is a prominent serum glycoprotein and a major noncollagenous component of mineralized bone in mammals. In this study, we show that recombinant fetuin and native serum protein have similar potency as inhibitors of osteogenesis in dexamethasone-treated rat bone marrow cell cultures (dex-RBMC). Recombinant bovine fetuin also bound to TGF-beta1 and BMP-2 in vitro with kinetics similar to native fetuin. Although TGF-beta1 is required for osteogenesis in dex-RBMC, the cytokine also inhibited osteogenesis at concentrations >/=10 pM. Titration of fetuin or anti-TGF-beta1 antibodies into the bone marrow cultures in the presence of 10 pM TGF-beta1 restored osteogenesis, whereas titrations of the same reagents into cultures with 0.3 pM added TGF-beta1 were inhibitory, confirming the biphasic nature of the TGF-beta1 response. Suppression of osteogenesis by both TGF-beta1 and the antagonist proteins required their presence within the first 6 days of culture, well before mineralization at 10-12 days. Northern analysis showed that both fetuin and high dose TGF-beta1 suppressed expression of the bone-associated transcripts alkaline phosphatase, osteopontin, collagen type I, and bone sialoprotein. The suppression of osteogenesis by fetuin and by high dose TGF-beta1 was accompanied by the differentiation of an alternate cell lineage with adipocyte characteristics. In summary, the biphasic osteogenic response to TGF-beta1 suggests that overlapping gradients of TGF-beta/BMP cytokines and fetuin regulate osteogenesis in remodeling bone.

Levels of transferrin and alpha 2-HS glycoprotein in women with and without endometriosis

The study objective was to test the hypothesis that elevated levels of transferrin and alpha 2-HS glycoprotein occur in the peritoneal environment of patients with endometriosis that may lead to the observed autoimmunity to these proteins. We set up a double sandwich enzyme-linked immunosorbent assay (ELISA) for measuring levels of transferrin and alpha 2-HS glycoprotein in the serum and peritoneal fluid samples from women with (n = 24-60) and without endometriosis (n = 35-49). Serum and peritoneal fluid levels of alpha 2-HS glycoprotein and peritoneal fluid levels of transferrin were significantly elevated in patients with endometriosis, in contrast to the controls. Serum levels of transferrin in patients, however, were significantly less in the patients than in controls. We conclude that transferrin and alpha 2-HS glycoprotein are present at high concentrations in the peritoneal fluids of patients with endometriosis. This may play a significant role in the autoimmune pathophysiology of endometriosis.

Distribution of lymphocyte subsets in bone marrow and peripheral blood is associated with haptoglobin type. Binding of haptoglobin to the B-cell lectin CD22

Haptoglobin is an acute phase protein showing a genetic polymorphism with 3 major types: Hp 1-1, Hp 2-1, and Hp 2-2. In this study, flow cytometric analysis demonstrated that all three haptoglobin types bind to CD22 on human B-lymphocytes with equal affinity. Comparison of reference values for lymphocyte subsets in peripheral blood and bone marrow showed significant differences between haptoglobin types. Haptoglobin 2-2 is associated with higher peripheral B-lymphocyte counts (P < 0.001) and CD4+ T-lymphocyte counts (P < 0.05). In bone marrow, CD4+ T-cell percentages were highest (P < 0.001) but B-cell percentages were lowest (P < 0.001) in haptoglobin 2-2 type. A negative correlation between serum haptoglobin 1-1 concentration and peripheral B-cell counts was observed (r = -0.663). Our results suggest that haptoglobin is involved in lymphocyte distribution. The present findings are a potential cause of over- or underestimation of lymphocyte subset counts in the clinical staging of immunodeficiency diseases.

Solid-phase synthesis of an O-linked glycopeptide based on a benzyl-protected glycan approach

The solid-phase synthesis of asialo-[Ala18]-B-chain (2) of human alpha 2HS glycoprotein is described. Disaccharide-linked serine unit 12, carrying a benzyl protecting group, was synthesized via stereoselective glycosylation of 8 with 6. Peptide synthesis was carried out by the Fmoc method utilizing an automated peptide synthesizer. A modified procedure using a mechanical shaker at the coupling step with 12 made easy the recovery of unreacted 12. The benzylated glycopeptide thus synthesized was cleaved from the resin and hydrogenated to give 2.

Antibodies to endometrial transferrin and alpha 2-Heremans Schmidt (HS) glycoprotein in patients with endometriosis

PROBLEM

Identifying the endometrial antigens inciting autoimmunity is important in setting up an antibody assay for a non-invasive diagnosis and clinical monitoring of endometriosis.

METHODS

Two-dimensional gel electrophoresis of endometrial extracts, Western blot analysis, passive hemagglutination and enzyme-linked immunosorbent assay (ELISA), amino acid sequencing and molecular studies were done on chosen antigens. Forty-six women with endometriosis, 4 women with uterine leiomyomata, 4 with pelvic adhesions, 3 with repeat Cesarean sections (conditions that coexist with or predispose to endometriosis) and 46 controls participated.

RESULTS

Antigens with molecular weights (MW) of 64 kDa [isoelectric point (pI) of 3.5-4.0] and 72 kDa (pI of 4.5) bound to IgG in all patients with endometriosis, but not the controls. Amino acid sequencing of the proteins revealed that they had homology to alpha 2-Heremans Schmidt (HS) glycoprotein (MW: 64 kDa) and transferrin (MW: 72 kDa). Endometriosis patients had significant antibody levels to these two proteins (predictive value of 80-90%). The analysis of patients' endometrial RNA detected the message for alpha 2-HS glycoprotein and transferrin. Albumin (pI 5.5) and collagen (pI 3.5) failed to elicit antibody responses.

CONCLUSIONS

Patients with endometriosis have significant antibodies to endometrial transferrin and alpha 2-HS-glycoprotein. We can effectively use an antibody assay using these antigens for diagnosing endometriosis.

Glycosylation of alpha-1-proteinase inhibitor and haptoglobin in ovarian cancer: evidence for two different mechanisms

The change in glycosylation of the two acute-phase proteins, alpha-1-proteinase inhibitor (API) and haptoglobin (Hp), in progressive ovarian cancer is different. This has been shown by monosaccharide analysis and lectin-binding studies of proteins purified from serum. In the glycan chains of API, there is decreased branching (more biantennary chains), less branches ending in alpha 2-3 sialic acid, more branches ending in alpha 2-6 sialic acid and more fucose, probably linked alpha 1-6 to the core region. On the other hand, Hp shows increased branching (more triantennary chains), more branches ending in alpha 2-3 sialic acid, less branches ending in alpha 2-6 sialic acid, and more fucose, probably in the alpha 1-3 linkage at the end of the chains. This is surprising because API and Hp are thought to be glycosylated by a common pathway in the liver. We have also shown that the fucose-specific lectin, lotus tetragonolobus, extracts abnormal forms of both Hp and API in ovarian cancer, but the expression of this Hp is related to tumour burden and the expression of this API is related to lack of response to therapy. It is suggested that this difference in the behaviour of API and Hp in ovarian cancer may be associated with the different changes in their glycosylation. Of the many mechanisms that could explain these findings, a likely one is that a pathological process is removing API with triantennary chains from the circulation.(ABSTRACT TRUNCATED AT 250 WORDS)

Inhibitory effect of calf fetuin on the cytotoxic activity of LAK cell-derived factors and tumor necrosis factor

A protein-inhibiting LAK cell-mediated cytotoxicity was isolated from a LAK cell-conditioned medium. The N-terminal amino acid sequence of this protein appeared to be identical to fetal calf fetuin. Pure isolated fetuin, as well as commercially available preparations of this protein, were shown to inhibit cytotoxic activity of both cytotoxic proteins released by LAK cells and TNF.

Structure of the N- and O-glycans of the A-chain of human plasma alpha 2HS-glycoprotein as deduced from the chemical compositions of the derivatives prepared by stepwise degradation with exoglycosidases

The structure of the glycans of the A-chain of human plasma alpha 2HS-glycoprotein was established from the chemical compositions of its derivatives prepared by sequential enzymatic degradation of the carbohydrate moiety, from the determination of the kind and amount of the monosaccharides liberated after each step of the enzymatic digestion, and from the distinct specificity of the highly purified exoglycosidases. The exoglycosidases were three sialidases (Vibrio cholerae, fowl plague virus, and Arthrobacter ureafaciens), two beta-galactosidases (Streptococcus pneumoniae and bovine testis), one alpha-N-acetylgalactosaminidase, one beta-N-acetylglucosaminidase, and one alpha-mannosidase. Utilizing sialidases with different cleavage specificities, the number of alpha 2-3- and alpha 2-6-linked sialic acid residues could be separately determined. As to the beta-galactosidases, the enzyme isolated from S. pneumoniae cleaves only beta 1-4-linked galactose residues, whereas the bovine testes enzyme acts on both the beta 1-4- and beta 1-3-linked galactose residues. Jack bean beta-N-acetylglucosaminidase cleaves beta 1-2, beta 1-4, and beta 1-6 GlcNAc with higher activity for the beta 1-2. Jack bean alpha-mannosidase cleaves alpha 1-2, alpha 1-6, and alpha 1-3 Man with greater activity for alpha 1-2 and alpha 1-6. Bovine liver alpha-N-acetylgalactosaminidase cleaves O-linked GalNAc. On the basis of these results, the A-chain of alpha 2 HS-glycoprotein was found to possess two biantennary N-glycans and two O-linked trisaccharides.

Serum alpha 2-HS glycoprotein concentration in patients with hematological malignancies. A follow-up study

We observed significantly reduced serum alpha 2-HS glycoprotein concentrations in patients with acute lymphocytic, acute nonlymphocytic, chronic granulocytic and chronic myelomonocytic leukemias, Hodgkin's and non-Hodgkin's lymphomas, myelofibrosis, and multiple myeloma, but not in patients with chronic lymphocytic leukemia and polycythemia vera, as compared with healthy controls. We followed the serum level of the protein for 18 months. Patients with infectious complications, those receiving cytostatic treatment, and those in the preterminal period had further reduced serum alpha 2-HS glycoprotein levels. The reduction of serum alpha 2-HS glycoprotein concentration was primarily due to decreased production caused by infiltration of the liver, a hepatotoxic effect of cytostatic treatment, and, to a lesser degree, to increased consumption. We found statistically significant negative correlations between serum alpha 2-HS glycoprotein concentration and erythrocyte sedimentation rate, serum aspartate aminotransferase and alkaline phosphatase activities, and IgG and IgM concentrations. The determination of the alpha 2-HS glycoprotein concentration is useful for the assessment and follow-up of the clinical status and therapy of patients with hematological malignancies and also has prognostic significance.

Alpha 1-antitrypsin and survival in pancreatic cancer

The association between serum levels of alpha 1-antitrypsin (a1AT) at the time of diagnosis and survival was studied in a group of 44 patients with confirmed pancreas cancer. All 44 patients were followed until time of death, which occurred in all cases from pancreas cancer, with a median time of 3 months and a range of 0.5 to 16 months. Cox's proportional hazards model was utilized in the analysis controlling for sex, age and tobacco smoking. Males, older patients and smokers have higher fatality rates, but none of these relations was statistically significant. By contrast, there was a statistically highly significant association of increased levels of serum a1AT, at the time of diagnosis of the cancer of pancreas, with shorter survival; patients with serum a1AT higher by 100mg/100ml had a 57% higher fatality rate. These results indicate that serum a1AT represents a clinically interesting prognostic factor in pancreas cancer.

Therapeutic plasmapheresis and protein A immunoadsorption in malignancy: a brief review

Plasmapheresis is being used with considerable frequency in the management of malignant and non-malignant disorders. More recently, staphylococcal Protein A immunoadsorption has been employed in similar clinical situations. In patients with malignancy, plasmapheresis has been shown to produce alterations in plasma proteins, decrease circulating immune complexes, remove "specific" and "non-specific" blocking factors, change immune reactivity, and affect monocyte function. Partial responses have been reported in a small number of patients with carcinoma of lung, colon, and breast following plasmapheresis. In addition, there are reports of favorable responses in patients with melanoma, head and neck tumors, lymphomas, leukemias, and Kaposi's sarcoma in acquired immune deficiency. All these responses were partial and brief, and the treatment did not alter the course of the disease. Plasmapheresis has been useful in the management of hyperviscosity and occasionally of paraneoplastic syndromes. It may also have a role in the treatment of thrombotic thrombocytopenic purpura associated with mitomycin-C therapy. Protein A immunoadsorption, by which circulating immune complexes are selectively removed, can activate the complement system, increase blastogenic responses, and increase the natural killer cell activity. It has been shown to produce partial responses in breast and colon cancer, as well as Kaposi's sarcoma in acquired immune deficiency. It may have a useful role to play in the management of mitomycin-C-associated thrombotic thrombocytopenic purpura. Both plasmapheresis and Protein A immunoadsorption should be considered investigational interventions at this time. Toxicity of plasmapheresis, though uncommon, can be serious and may rarely be fatal. Toxicity of Protein A immunoadsorption is mild, consisting mainly of influenza-like symptoms and rash.

Alpha 1-antitrypsin and survival in hepatocellular carcinoma

The association between serum levels of alpha 1-antitrypsin (alpha 1 AT) at the time of diagnosis and survival was studied in a group of 78 patients with confirmed hepatocellular carcinoma (HCC). All 78 patients were followed until the time of death, which occurred in all instances from HCC, with a median time of 6 months and a range of 1-117 months. Cox's proportional hazards model was utilised in the analysis controlling for sex, age, HBsAg status and logarithmically transformed values of alpha-fetoprotein (alpha-FP). Older patients and patients positive for HBsAg have suggestively higher fatality rates (0.05 less than P less than 0.10) whereas in these data sex and AFP levels were not important prognostic factors. Increased levels of serum at alpha 1AT at the time of diagnosis of HCC were statistically significantly (P less than 0.05) related with shorter survival, patients with higher serum alpha 1AT by 200 mg 100 ml-1 having an expected survival time shorter by about 25%.

Relationship between radiological classification and the serological and haematological features of untreated pulmonary tuberculosis in Indonesia

Immunological and metabolic responses were studied in 110 patients with newly diagnosed pulmonary tuberculosis and 32 healthy controls from similar socioeconomic backgrounds. The severity of lung involvement was assessed radiologically, but this was not related to the current features of cell mediated immunity or to those of many aspects of the serological response to Mycobacterium tuberculosis. However, the patients with more extensive pulmonary tuberculosis showed higher titres of IgG2 antibody to whole killed M. tuberculosis and to the ML34 epitope shared by many species of mycobacteria. The patients with more extensive pulmonary tuberculosis showed a more marked metabolic response to infection as manifested by changes in serum levels of acute phase reactant proteins. Accordingly, the metabolic responses are considered to be more likely to prove of value in clinical monitoring of patients for severity of infection, or of reactivation of infection with M. tuberculosis, than immunological responses.

Genetic variation of haptoglobin and transferrin in relation to DNA content and stage in renal cell carcinoma

Four genetic marker systems were investigated in 102 patients with renal cell carcinoma. The previously observed excess of the transferrin (TF) variant C3 among male patients was confirmed. Interestingly, an excess of TFC3 and a deficit of the haptoglobin heterozygote, HP2-1, were associated with diploid tumor DNA content and Stage I, particularly in male patients. The results are discussed in terms of a possible genetic influence on tumor progression.

The position of the disulfide bonds in human plasma alpha 2 HS-glycoprotein and the repeating double disulfide bonds in the domain structure

The positions of the inter- and intra-chain disulfide bonds of human plasma alpha 2 HS-glycoprotein were determined. alpha 2 HS-glycoprotein was digested with acid proteinase and then with thermolysin. The disulfide bonds containing peptides were separated by reversed-phase HPLC and detected by SBD-F (7-fluorobenzo-2-oxa-1,3-diasole-4-sulfonic acid ammonium salt) method. One inter-disulfide bond containing peptide and five intra-disulfide bond containing peptides (A-chain) were purified and identified as Cys-18 (B-chain)--Cys-14 (A-chain), Cys-71--Cys-82, Cys-96--Cys-114, Cys-128--Cys-131, Cys-190--Cys-201 and Cys-212--Cys-229, respectively. The location of the intra-disulfide bonds revealed that the A-chain of alpha 2 HS-glycoprotein is composed of three domains. Two domains were shown to possess intramolecular homology judging from the total chain length of the domains, size of the loops formed by the S--S bonds, the location of two disulfide loops near the C-terminal end of domains A and B, the distance between two S--S bonds of each domain, the amino acid sequence homology between these two domains (22.6%), number of amino acid residues between the second S--S loops and the end of domains A and B, and the positions of the ordered structures.

Diagnosis of head and neck carcinomas by means of immunological tumour markers (Beta-2-microglobulin, immunoglobulin E, ferritin, N-acetyl-neuraminic acid, phosphohexose-isomerase)

In a great number of patients with squamous cell cancer of the head and neck, tumour markers in the serum were determined before any therapy, in order to evaluate their possible usefulness as parameters for monitoring therapy as well as for early detection of cancer. Patients with primary tumours (n = 101) were distributed to groups TI-II and TIII-IV according to the UICC classification 1978, and investigated together with a group of recurrences (n = 105). 50 age-matched healthy individuals served as controls. Substances investigated were beta 2-Microglobulin (beta 2-M), Immunoglobulin E (IgE), Ferritin, N-Acetyl-Neuraminic Acid (sialic acid; NANA), Phosphohexose-Isomerase (PHI). Not only were the mean values of the groups compared with each other, but also the percentages of the respective groups displaying increases above the upper norm limit (95. percentile) were calculated. Critical evaluation of the results led to the conclusion that in particular IgE, NANA and--with some reservations--ferritin should be further investigated as biological serum markers in serial determination with special regard to their possible relevance for cancer treatment.

Three forms of BRP-2 (bone resorptive proteins) from human cancer ascites fluid and their relationship to human serum alpha-2 HS-glycoprotein

Two new forms of BRP-2, a previously described bone resorptive protein, were purified from ascites fluids obtained from patients with hypercalcemia and metastatic bone cancer. The apparent molecular weights of BRP-2 and of these two proteins were 52,000, 48,000, and 46,000, respectively, as determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis. The three proteins have essentially the same amino acid compositions but differ with respect to their carbohydrate moieties. The amino-terminal amino acid sequences of the three glycoproteins were identical to each other as well as to human serum alpha 2HS-(human serum) glycoprotein. The relationship of the three forms of BRP-2 to alpha 2HS was also established immunochemically. The ascites proteins, as well as alpha 2HS, on a molar basis, were approximately one-tenth as potent as bovine parathyroid hormone fragment (1-34) in their abilities to stimulate calcium release from bone in vitro. This study describes for the first time a possible function for human serum alpha 2HS.

A fetuin-related glycoprotein (alpha 2HS) in human embryonic and fetal development

The human plasma protein, alpha 2HS glycoprotein, has an amino acid composition very similar to that of fetuin, the major protein in fetal calf and lamb serum. Immunohistochemical studies of human fetuses (6-33 weeks gestation) showed that alpha 2HS glycoprotein and fetuin have similar distributions in developing brain and several other tissues, e.g., bone, kidney, gonads, gastrointestinal tract, respiratory and cardiovascular systems. There were notable differences in the liver and thymus in the distribution of the two proteins. Fetuin and alpha 2HS glycoprotein are present in plasma and cerebrospinal fluid of both human and sheep fetuses; their concentrations are reciprocally related: in human plasma and cerebrospinal fluid alpha 2HS glycoprotein concentration is high and fetuin low; the reverse is the case in sheep fetuses. Estimates of the concentration of alpha 2HS glycoprotein in human fetal cerebrospinal fluid and plasma were obtained. It is suggested that alpha 2HS glycoprotein may play a role in developing tissues, especially in the human fetus, similar to that of fetuin in other species.

Serum glycoproteins and prognosis in cancer of the head and neck

Alpha 1 acid glycoprotein, alpha 1 antitrypsin, haptoglobin, alpha 2 HS glycoprotein and prealbumin were studied in 44 patients with cancer of the head and neck and in a control group. The three primary glycoproteins were considerably elevated in the patients, particularly in stage IV. In the group of patients who died before 30 months after treatment the haptoglobin was significantly elevated compared to those who survived beyond this point. Only values for the alpha 1 acid glycoprotein greater than 150 mg/dl were a prognostic factor of similar precision to that of stage IV. This correlation could not be shown for the other glycoproteins.

Prognostic significance of serum alpha 1-acid glycoprotein in patients with glioblastoma multiforme: a preliminary communication

The relationship between the levels of serum acute phase reactant proteins (alpha 1-acid glycoprotein, alpha 1-antitrypsin, haptoglobin) was investigated in patients with glioblastoma multiforme in relation to their prognosis. Alpha 1-acid glycoprotein was higher in the patients who died within one year after admission than in those with a longer survival time. It is suggested that serum alpha 1-acid glycoprotein profiles provide prognostic information in patients with glioblastoma multiforme.

Haptoglobin: an immunoregulatory role in tuberculosis?

A significant correlation was found between levels of haptoglobin in sera from Indonesian patients with tuberculosis and the extent to which these sera suppressed mitogen-driven activation of normal lymphocytes in vitro. As in a previous study we showed that there was an inverse relationship between haptoglobin levels and the circulating lymphocyte count in the same group of patients, it is now suggested that this protein has an immunoregulatory role in tuberculosis. Similar observations have been made by other workers on patients with cancer. There was no difference in the distribution of the 3 allotypes of haptoglobin in patients and healthy subjects nor was there any association between such allotypes and the lymphocyte count, the dermal reactivity to tuberculin or the degree of suppression.

The prognostic significance of acute phase proteins in patients with inoperable squamous cell carcinoma of the bronchus

In 95 patients with inoperable squamous cell carcinoma of the bronchus, nine potential serum "markers" were analysed for their prognostic significance. Lactate dehydrogenase, alpha 1 HS-glycoprotein, ferritin, carcino-embryonic antigen and immunoglobulin E did not prove to be useful as prognostic indices. The erythrocyte sedimentation rate and the acute phase proteins alpha 1 acid glycoprotein, C-reactive protein and prealbumin were correlated with survival. After taking the performance status and tumour stage into account, C-reactive protein still proved to be a strong prognosticator. The clinical relevance of the acute phase proteins signifying a so-called "biochemical status" next to the "clinical status" is discussed.