Gemcitabine-capecitabine in platinum-refractory patients with thymic epithelial tumors

7590

Background: Platinum based combination chemotherapy is the actual standard of care for advanced and recurrent Thymic epithelial tumours-TET (thymoma and thymic carcinoma). Additional agents are needed in this setting. We have designed a pilot study, phase II multicenter, to evaluate the efficacy and safety of no tested schedule gemcitabine-capecitabine in patients refractory to platinum based chemotherapy. Methods: Eligible patients had pathologically confirmed TET and were treated with at least 2 lines of chemotherapy, one of this being a platinum based schedule. From January 2007 to September 2008 twelve pts were enrolled. Treatment Schedule: Gemcitabine 1,000 mg/m2 by 30-minute infusion on days 1 and 8 every 3 weeks plus oral capecitabine 650 mg/m2 twice daily on days 1 to 14. Response was evaluated at 3 and 6 cycles. Results: Pts Characteristics: 12 pts (7 M-5F, Median Age 51,3 yrs,range 27–76). 7 pts had received Thymectomy and 4 of this had received also surgery for metastatic disease. 5 pts have received only thymic biopsy. Performance status sec. Karnofsky was 90% (range 80–100). Site of disease: liver, lung, bone, nodal, pleural and pericardium. All pts were staged IVB sec. Masaoka. Tumors were classified by WHO classification as follows: 4-B2, 8-B2/B3. All pts were evaluated as concerns performance status and all had Karnofcky 90% (range 80–100). Sites of metastatic disease were: liver,lung,bone,nodal, pleural and pericardium. Associated paraneoplastic syndromes were: myasthenia in 7 pts, B-lymphopenia 11 pts. The minimum number of cycles administered on study was 3 (range 3–8).Among the 12 enrolled pts there were 10 objective response: 2 CR, 8 PR. 2 pts had SD. Prolonged maintenance of absence of disease was obtained in the 2 pts reporting a CR (more than 6 months in 1 patient). Treatment was well tolerated, no grade 4 toxicities was registered. Conclusions: The combination schedule gemcitabine-capecitabine have an high activity in Thymic malignancies in pts heavily pretreated with advanced recurrent TET and appears to be a safe option in platinum-refractory TET pts. This schedule must be proposed to be used also in randomized clinical trial compared with platinum based treatment.

No significant financial relationships to disclose.

Nuclear receptors CAR and PXR: Molecular, functional, and biomedical aspects

Nuclear receptors (NRs) are ligand-activated transcription factors sharing a common evolutionary history and having similar sequence features at the protein level. Selective ligand(s) for some NRs is not known, therefore these NRs have been named "orphan receptors". Whenever ligands have been recognized for any of the orphan receptor, it has been categorized and grouped as "adopted" orphan receptor. This group includes the constitutive androstane receptor (CAR) and the pregnane X receptor (PXR). They function as sensors of toxic byproducts derived from endogenous metabolites and of exogenous chemicals, in order to enhance their elimination. This unique function of CAR and PXR sets them apart from the steroid hormone receptors. The broad response profile has established that CAR and PXR are xenobiotic sensors that coordinately regulate xenobiotic clearance in the liver and intestine via induction of genes involved in drug and xenobiotic metabolism. In the past few years, research has revealed new and mostly unsuspected roles for CAR and PXR in modulating hormone, lipid, and energy homeostasis as well as cancer and liver steatosis. The purpose of this review is to highlight the structural and molecular bases of CAR and PXR impact on human health, providing information on mechanisms through which diet, chemical exposure, and environment ultimately impact health and disease.

Appropriateness of colonoscopy in a digestive endoscopy unit: a prospective study using ASGE guidelines

RATIONALE, AIMS AND OBJECTIVES

Appropriate indications for colonoscopy (C) are essential for a rational use of resources. The aim of this study is to evaluate the appropriateness of indication for C according to the American Society for Gastrointestinal Endoscopy (ASGE) guidelines and to evaluate whether appropriate use was correlated with the diagnostic yield of C.

METHODS

We analysed 677 consecutive C performed over an 11-month period in a digestive endoscopy unit with an open access system.

RESULTS

The rate of 'generally indicated' C was 77% and 'generally not indicated' C was 18%. The rate of indication not listed in the ASGE guidelines was 5%. The percentage of generally not indicated C requested by gastroenterologists for outpatients was lower than that requested by primary care surgeons or doctors (9.5%, 29%, 25.3%, respectively). In 38 (7.3%) and in 111 (21.3%) of 520 patients with appropriate C, cancer and polyps larger than 5 mm were found, respectively. Twenty polyps greater than 5 mm were detected in 15 cases (12%) of 122 inappropriate C, with only one case of intramucosal carcinoma; four (12%) polyps measuring over 5 mm were found in C not listed in ASGE guidelines. No advanced stage cancer was detected in the inappropriate group and in C not listed in ASGE guidelines.

CONCLUSIONS

Our results showed the high rate of inappropriate procedures, according to ASGE guidelines, requested by surgeons, internists and primary care doctors for both outpatients and inpatients. The proportion of not indicated endoscopic procedures requested by gastroenterologists must be reduced through more carefully application of ASGE guidelines. Endoscopic findings were more stringent in appropriate C.

Effect of bisphenol A with or without enzyme treatment on the proliferation and viability of MCF-7 cells

Recently, aqueous solutions polluted by BPA have been bioremediated by us using laccase immobilized on hydrophobic membranes in non-isothermal bioreactors. BPA degradation was checked using analytical methods. To assess in vitro the occurred bioremediation, the proliferation and viability indexes of MCF-7 cells incubated in the presence of aqueous solutions of BPA, or of enzyme-treated BPA solutions, have been measured as a function of the initial BPA concentration. The results demonstrated that: i) at each initial BPA concentration used, both the proliferation and viability indexes are a function of the duration of enzyme treatment; ii) proliferation and viability are uncoupled biological processes with respect to BPA enzyme treatment. Non-isothermal bioreactors are a useful tool for the bioremediation of aqueous solutions polluted by BPA, which is an example of an endocrine disruptor that belongs to the alkyl phenol family.

Regulation of cellular signals from nutritional molecules: a specific role for phytochemicals, beyond antioxidant activity

Phytochemicals (PhC) are a ubiquitous class of plant secondary metabolites. A "recommended" human diet should warrant a high proportion of energy from fruits and vegetables, therefore providing, among other factors, a huge intake of PhC, in general considered "health promoting" by virtue of their antioxidant activity and positive modulation, either directly or indirectly, of the cellular and tissue redox balance. Diet acts through multiple pathways and the association between the consumption of specific food items and the risk of degenerative diseases is extremely complex. Recent literature suggests that molecules having a chemical structure compatible with a putative antioxidant capacity can actually "perform" activities and roles independent of such capacity, interacting with cellular functions at different levels, such as affecting enzyme activities, binding to membrane or nuclear receptors as either an elective ligand or a ligand mimic. Inductive or signaling effects may occur at concentrations much lower than that required for effective antioxidant activity. Therefore, the "antioxidant hypothesis" is to be considered in some cases an intellectual "shortcut" possibly biasing the real understanding of the molecular mechanisms underlying the beneficial effects of various classes of food items. In the past few years, many exciting new indications elucidating the mechanisms of polyphenols have been published. Here, we summarize the current knowledge of the mechanisms by which specific molecules of nutritional interest, and in particular polyphenols, play a role in cellular response and in preventing pathologies. In particular, their direct interaction with nuclear receptors and their ability to modulate the activity of key enzymes involved in cell signaling and antioxidant responses are presented and discussed.

Membrane association of estrogen receptor alpha and beta influences 17beta-estradiol-mediated cancer cell proliferation

S-Palmitoylation is a widespread post-translational modification of integral and/or peripheral proteins occurring in all eukaryotic cells. The family of S-palmitoylated proteins is large and diverse and recently, estrogen receptor isoforms (ERalpha and ERbeta) belonging to the nuclear receptor superfamily have been added to the palmitoylproteoma. S-Palmitoylation allows ERalpha and ERbeta localization at the plasma membrane, where they associate with caveolin-1. Upon 17beta-estradiol (E2) stimulation, ERalpha dissociates from caveolin-1 allowing the activation of rapid signals relevant for cell proliferation. In contrast to ERalpha, E2 increases ERbeta association with caveolin-1 and activates p38 kinase and the downstream pro-apoptotic cascade (i.e., caspase-3 activation and PARP cleavage). These data highlight the physiological role of palmitoylation in modulating the ERalpha and ERbeta localization at the plasma membrane and the regulation of different E2-induced non-genomic functions relevant for controlling cell proliferation.

Omega-3 as well as caloric restriction prevent the age-related modifications of cholesterol metabolism

Intracellular concentration of cholesterol is regulated by the balance between endogenous synthesis and exogenous uptake; endogenous synthesis is subject to feedback control of hepatic 3-hydroxy-3-methyl-glutaryl-CoA reductase activity, while the exogenous supply is mainly controlled by the modulation of the low-density lipoprotein receptor. During ageing, hepatic lipid modifications occur and caloric restriction are able to prevent these changes. So, the aim of this work was to evaluate the mechanisms underlying the effect exerted both by caloric restrictions and by a diet enriched with Omega-3 fatty acids, on the cholesterol plasma levels during ageing, by studying the regulation of the protein involved in cholesterol homeostasis maintenance. Livers from diet restricted and Omega-3 supplemented diet fed 24-month-old rat were used to analyze, the protein complex of cholesterol homeostasis maintenance and those ones that are able to modulate 3-hydroxy-3-methyl-glutaryl-CoA reductase. The data obtained demonstrate that both caloric restriction and Omega-3 supplemented diets are able to prevent hypercholesterolemia, by regulating HMG-CoAR activation state by controlling ROS production and p38 phosphorylation. Moreover also the age-dependent loss of LDLr membrane exposition is prevented.

The nutritional flavanone naringenin triggers antiestrogenic effects by regulating estrogen receptor alpha-palmitoylation

Naringenin (Nar) is a component of fruits and vegetables associated with healthful benefits, such as in osteoporosis, cancer, and cardiovascular diseases. These protective effects have been linked with Nar antiestrogenic as well as estrogenic activities. Previous studies indicate that Nar impaired estrogen receptor (ER) alpha signaling by interfering with ERalpha-mediated activation of ERK and phosphoinositide 3-kinase signaling pathways in the absence of effects at the transcriptional level. The present studies evaluated the hypothesis that these Nar antagonistic effects occur at the level of the plasma membrane. Our results indicate that Nar induces ERalpha depalmitoylation faster than 17beta-estradiol, which results in receptor rapid dissociation from caveolin-1. Furthermore, Nar impedes ERalpha to bind adaptor (modulator of nongenomic actions of the ER) and signaling (c-Src) proteins involved in the activation of the mitogenic signaling cascades (i.e. ERK and phosphoinositide 3-kinase). On the other hand, Nar induces the ER-dependent, but palmitoylation-independent, activation of p38 kinase, which in turn is responsible for Nar-mediated antiproliferative effects in cancer cells. Altogether, these data highlight new ER-dependent mechanisms on the root of antiproliferative and antiestrogenic effects of Nar. Moreover, the different modulation of ERalpha palmitoylation exerted by different ligands represents a pivotal mechanism that drives cancer cell to proliferation or apoptosis.

Estrogen regulation of adipose tissue functions: involvement of estrogen receptor isoforms

Adipose tissue has recently been described as one of the major endocrine gland that plays a role in energy homeostasis, lipid metabolism, immune response, and reproduction. An excess of white adipose tissue, caused by a complex interaction between genetic, hormonal, behavioral, and environmental factors, results in obesity: a heterogeneous disorder that predisposes humans to a variety of diseases. Among several hormones, estrogens promote, maintain, and control the typical distribution of body fat and adipose tissue metabolism through still unknown mechanisms. These steroids are known to regulate fat mass, adipose deposition and differentiation, and adipocyte metabolism. Moreover, estrogen deficiency results in increases in adipose tissue, preferentially in visceral fat, which would link obesity to the susceptibility of related disorders. In this review the role of estrogens in adipose tissue differentiation and in the protection against the onset of obesity will be discussed with particular attention being drawn to the underlying molecular mechanisms mediated by estrogen receptor isoforms ERalpha and ERbeta.

[Pulmonary alveolar proteinosis: report of two cases and review of the literature]

Pulmonary alveolar proteinosis is a rare disease characterized by extensive radiological and tomographic pulmonary lesions and a variable clinical picture ranging from pulmonary insufficiency to spontaneous remission. Among its three described forms, the so called Idiopathic or Adult form is responsible for more than 80% of published cases. It's physiopathology depends on an autoimmune process directed against the GM-CSF (Granulocite Macrophage- Colony Stimulating Factor) that induces a functional defect of the macrophage with consequent intraalveolar accumulation of surfactant. Pulmonary and extrapulmonary infections, are common, often with unusual pathogens. Diagnosis can be made from the combination of clinical, radiological and bronchoalveolar lavage data, although sometimes histopathologic material is needed for confirmation. Total pulmonary lavage is currently the treatment of choice. Mortality is usually low and related mostly to infectious complications. We hereby describe our experience with two patients.

A mononucleotide markers panel to identify hMLH1/hMSH2 germline mutations

Hereditary NonPolyposis Colorectal Cancer (Lynch syndrome) is an autosomal dominant disease caused by germline mutations in a class of genes deputed to maintain genomic integrity during cell replication, mutations result in a generalized genomic instability, particularly evident at microsatellite loci (Microsatellite Instability, MSI). MSI is present in 85–90% of colorectal cancers that occur in Lynch Syndrome. To standardize the molecular diagnosis of MSI, a panel of 5 microsatellite markers was proposed (known as the “Bethesda panel”). Aim of our study is to evaluate if MSI testing with two mononucleotide markers, such as BAT25 and BAT26, was sufficient to identify patients with hMLH1/hMSH2 germline mutations. We tested 105 tumours for MSI using both the Bethesda markers and the two mononucleotide markers BAT25 and BAT26. Moreover, immunohistochemical evaluation of MLH1 and MSH2 proteins was executed on the tumours with at least one unstable microsatellite, whereas germline hMLH1/hMSH2 mutations were searched for all cases showing two or more unstable microsatellites.

The Bethesda panel detected more MSI(+) tumors than the mononucleotide panel (49.5% and 28.6%, respectively). However, the mononucleotide panel was more efficient to detect MSI(+) tumours with lack of expression of Mismatch Repair proteins (93% vs 54%). Germline mutations were detected in almost all patients whose tumours showed MSI and no expression of MLH1/MSH2 proteins. No germline mutations were found in patients with MSI(+) tumour defined only through dinucleotide markers. In conclusion, the proposed mononucleotide markers panel seems to have a higher predictive value to identify hMLH1 and hMSH2 mutation-positive patients with Lynch syndrome. Moreover, this panel showed increased specificity, thus improving the cost/effectiveness ratio of the biomolecular analyses.

Expression of autoimmune regulator gene (AIRE) and T regulatory cells in human thymomas

Expression of the autoimmune regulator gene (AIRE) and the presence of CD25(+)/forkhead box p3 (FoxP3)(+) T regulatory (T(reg)) cells were investigated in histologically normal adult thymi and in thymomas using immunohistochemistry and quantitative real-time polymerase chain reaction (PCR). In the normal thymus staining for AIRE was detected in the nucleus of some epithelial-like cells located in the medulla; in thymomas AIRE-positive cells were extremely rare and could be detected only in the areas of medullary differentiation of two B1 type, organoid thymomas. RNA was extracted from 36 cases of thymoma and 21 non-neoplastic thymi obtained from 11 myasthenic (MG(+)) and 10 non-myasthenic (MG(-)) patients. It was found that AIRE is 8.5-fold more expressed in non-neoplastic thymi than in thymomas (P = 0.01), and that the amount of AIRE transcripts present in the thymoma tissue are not influenced by the association with MG, nor by the histological type. A possible involvement of AIRE in the development of MG was suggested by the observation that medullary thymic epithelial cells isolated from AIRE-deficient mice contain low levels of RNA transcripts for CHRNA 1, a gene coding for acetylcholine receptor. Expression of human CHRNA 1 RNA was investigated in 34 human thymomas obtained from 20 MG(-) patients and 14 MG(+) patients. No significant difference was found in the two groups (thymoma MG(+), CHRNA1 = 0.013 +/- 0.03; thymoma MG-, CHRNA1 = 0.01 +/- 0.03). In normal and hyperplastic thymi CD25(+)/Foxp3(+) cells were located mainly in the medulla, and their number was not influenced by the presence of MG. Foxp3(+) and CD25(+) cells were significantly less numerous in thymomas. A quantitative estimate of T(reg) cells revealed that the levels of Foxp3 RNA detected in non-neoplastic thymi were significantly higher (P = 0.02) than those observed in 31 cases of thymomas. Our findings indicate that the tissue microenvironment of thymomas is defective in the expression of relevant functions that exert a crucial role in the negative selection of autoreactive lymphocytes.

Perinatal hypoxia triggers alterations in K+ channels of adult pulmonary artery smooth muscle cells

Adverse events during the perinatal period, like hypoxia, have been associated with adult diseases. In pulmonary vessels, K(+) channels play an important role in the regulation of vascular tone. In the fetus, Ca(2+)-activated K(+) channels (K(Ca)) are predominant, whereas from birth voltage-gated K(+) channels (K(V)) prevail in the adult. We postulated that perinatal hypoxia could alter this maturational shift and influence regulation of pulmonary vascular tone in relation to K(+) channels in adulthood. We evaluated the effects of perinatal hypoxia on K(V) and K(Ca) channels in the adult main pulmonary artery (PA) using a murine model. Electrophysiological measurements showed a greater outward current in PA smooth muscle cells of mice born in hypoxia than in controls. In controls, only K(V) channels contributed to this current, whereas in mice born in hypoxia both K(V) and K(Ca) channels were implicated. K(V) channel activity was even higher in mice born in hypoxia than in controls. Therefore, perinatal hypoxia results in increased K(Ca) and K(V) channel activity in adult PA. Moreover, PA of adults born in hypoxia displayed higher large-conductance K(Ca) alpha-subunit and K(V)1.5 alpha-subunit protein expression than controls. Interestingly, relaxation induced by nitric oxide (NO) donors [S-nitroso-N-acetyl-D,l-penicillamine, 2-(N,N-diethylamino)-diazenolate-2-oxide] in isolated PA of control mice was not mediated by K(Ca) channels and only slightly by K(V) channels, whereas following perinatal hypoxia both K(Ca) and K(V) channels contributed to this relaxation. Thus perinatal hypoxia results in altered expression and activity of different K(+) channels in the adult main PA, which could contribute to modifications of pulmonary vasoreactivity.

17Beta-estradiol induces ERbeta up-regulation via p38/MAPK activation in colon cancer cells

Estrogen receptors (ERalpha and ERbeta) mediate opposite functions on cancer growth induced by 17beta-estradiol (E2). E2 binding to ERalpha induces a cancer promoting response, whereas E2 binding to ERbeta exerts a protective action against cancer growth. Moreover, E2 can diversely modulate the ERalpha and ERbeta levels intensifying or decreasing their actions in target tissues. Only molecular mechanisms at the root of E2 ability to down-regulate the ERalpha levels are known. Here, we report the first molecular mechanism underlying E2-induced ERbeta up-regulation in DLD-1 colon cancer cells. E2 induces a short term (2 and 4h after stimulation) translation of ERbeta mRNA followed by a late (24h after stimulation) enhanced transcription. Both processes required the E2-induced persistent and palmitoylation-dependent p38/MAPK activation. Overall, our data suggest a finely tuned control exerted by rapid signals on different cellular molecular events important for the protective effects of E2 against colon cancer growth.

Role of ERbeta palmitoylation in the inhibition of human colon cancer cell proliferation

The cellular functions regulated by 17beta-estradiol (E2) start after the hormone binds to its receptors (i.e., ERalpha and ERbeta). These act as ligand-dependent transcription factor transactivating target genes. In addition, E2 induces non-genomic actions, whose activation is triggered by a fraction of the ERs localized at the plasma membrane. Palmitoylation allows ERalpha to localize at the plasma membrane, to associate with caveolin-1, and, upon E2 stimulation, to activate rapid signals relevant for cell proliferation. The existence of a mechanism, which allows ERbeta localization at the plasma membrane and its putative role in anti-proliferative E2 effects is completely unknown. Here, the susceptibility of ERbeta to undergo palmitoylation and the role played by this process has been analyzed in DLD-1 containing endogenous ERbeta or in HeLa cells transiently transfected with ERbeta or ERalpha expression vectors. As for ERalpha, palmitoylation is necessary for ERbeta localization at the plasma membrane and its association with caveolin-1 but, in contrast to ERalpha, the E2 binding increases ERbeta association with caveolin-1 and the p38 member of MAPK family. Moreover, the palmitoyl acyl transferase (PAT) inhibitor blocks the ability of ERbeta-E2 complex to activate p38 impairing the receptor-dependent activation of downstream proapoptotic cascade (i.e., caspase-3 activation and poly(ADP-ribose)polymerase (PARP) cleavage). Consequently, palmitoylation must be considered to be a molecular device for ERbeta, which allows these receptors to interact with the plasma membrane and to regulate E2-induced non-genomic functions relevant to the anti-proliferative effect of this hormone.

Estrogen receptor beta (ERbeta) and inhibition of prostate cancer cell proliferation: studies on the possible mechanism of action in DU145 cells

Estrogen receptor beta (ERbeta) plays a protective role against uncontrolled cell proliferation. ERbeta is lost during prostate cancer (CaP) progression suggesting its direct involvement in contrasting tumor proliferation in this disease; however, the molecular mechanism at the basis of this effect has not been clearly defined yet. Possible molecular targets of ERbeta were assessed in DU145 cells, a CaP cell line expressing only ERbeta. Cells treated from 1 to 9 days with different doses of estradiol or diarylpropionitrile (DPN, an ERbeta-selective agonist) show a time-dependent decrease in cell proliferation. The reduced proliferation rate is accompanied by the stimulation of ERbeta expression and the increase of cyclin-dependent kinase inhibitor p21. We demonstrate that the endogenous ERbeta is one of the mediator of the antiproliferative action of estrogens enhancing the synthesis of molecules such as p21 that control cell cycle, an effect amplified by the autoregulation of ERbeta expression. Our observations suggest that CaP, when expressing a functional ERbeta, might be sensitive to the antiproliferative action of estrogens; therefore, ERbeta specific agonists might be valid candidates for new pharmacological approaches to this disease.

External fixation for displaced intra-articular fractures of the calcaneum

A minimally-invasive procedure using percutaneous reduction and external fixation can be carried out for Sanders' type II, III and IV fractures of the os calcis. We have treated 54 consecutive closed displaced fractures of the calcaneum involving the articular surface in 52 patients with the Orthofix Calcaneal Mini-Fixator. Patients were followed up for a mean of 49 months (27 to 94) and assessed clinically with the Maryland Foot Score and radiologically with radiographs and CT scans, evaluated according to the Score Analysis of Verona. The clinical results at follow-up were excellent or good in 49 cases (90.7%), fair in two (3.7%) and poor in three (5.6%). The mean pre-operative Böhler's angle was 6.98 degrees (5.95 degrees to 19.86 degrees), whereas after surgery the mean value was 21.94 degrees (12.58 degrees to 31.30 degrees) (p < 0.01). Excellent results on CT scanning were demonstrated in 24 cases (44.4%), good in 25 (46.3%), fair in three (5.6%) and poor in two (3.7%). Transient local osteoporosis was observed in ten patients (18.5%), superficial pin track infection in three (5.6%), and three patients (5.6%) showed thalamic displacement following unadvised early weight-bearing. The clinical results appear to be comparable with those obtainable with open reduction and internal fixation, with the advantages of reduced risk using a minimally-invasive technique.

Steroid hormone rapid signaling: The pivotal role of S-Palmitoylation

Nuclear receptors (NRs) comprise a large family of proteins essential to manipulate various aspects of human biology. The class III of the NR family includes steroid hormone receptors (SHRs) involved in embryonic development, maintenance of differentiated cellular phenotypes, metabolism, and cell death. Dysfunction of SHR signaling leads to proliferative, reproductive, and metabolic diseases. SHRs are ligand-activated transcription factors which regulate cellular processes by inducing genomic events. In addition, membrane-initiating non-genomic signals have been described for several SHRs. These non-genomic actions are independent of the SHR transcription activity and have been attributed to canonical SHRs and non-canonical hormone binding sites located at the plasma membrane. The molecular bases for SHR-plasma membrane association represent a debated issue. Here, we hypothesize that the SHR amino acid sequence homologous to that encompassing the S-palmitoylated Cys447 residue of human estrogen receptor alpha could represent a new consensus sequence for SHR S-palmitoylation. Reversible S-palmitoylation of SHRs could play a critical role in receptor localization at the plasma membrane and in rapid nongenomic signaling activation.

CO2 impairs peroxynitrite-mediated inhibition of human caspase-3

Peroxynitrite (ONOO-) is a transient powerful oxidant produced in vivo as the reaction of nitrogen monoxide (.NO) with superoxide (O2.-). The peroxynitrite reactivity is modulated by carbon dioxide (CO2) which enhances the peroxynitrite-mediated nitration of aromatics and partially impairs the oxidation of thiols. Here, the effect of CO2 on the peroxynitrite-mediated inhibition of human caspase-3, the execution enzyme of the apoptotic cascade, is reported. Peroxynitrite inhibits the catalytic activity of human caspase-3 by oxidizing the Sgamma atom of the Cys catalytic residue. In the absence of CO2, 1.0 equivalent of peroxynitrite inactivates 1.0 equivalent of human caspase-3. In the presence of the physiological concentration of CO2 (=1.3x10(-3) M), 1.0 equivalent of peroxynitrite inactivates only 0.38 equivalents of human caspase-3. Peroxynitrite affects the kcat value of the human caspase-3 catalyzed hydrolysis of N-acetyl-Asp-Glu-Val-Asp-7-amido-4-methylcoumarin, without altering Km. Both in the absence and presence of CO2, the reducing agent dithiothreitol does not prevent human caspase-3 inhibition by peroxynitrite and does not reverse the peroxynitrite-induced inactivation of human caspase-3. These results represent the first evidence for modulation of peroxynitrite-mediated inhibition of cysteine proteinase action by CO2, supporting the role of CO2 in fine tuning of cell processes (e.g., apoptosis).

Anti-MuSK antibodies: correlation with myasthenia gravis severity

The authors measured anti-muscle-specific tyrosine kinase (anti-MuSK) antibodies (Abs) in 83 serum samples from 40 patients and evaluated their correlation with myasthenia gravis severity and treatment response. Ab concentrations were often reduced by immunosuppression but not after thymectomy. Both in individual cases and in the whole population, a correlation between Ab levels and disease severity was found.

Structure-function relationship of estrogen receptor alpha and beta: impact on human health

17Beta-estradiol (E2) controls many aspects of human physiology, including development, reproduction and homeostasis, through regulation of the transcriptional activity of its cognate receptors (ERs). The crystal structures of ERs with agonists and antagonists and the use of transgenic animals have revealed much about how hormone binding influences ER conformation(s) and how this conformation(s), in turn, influences the interaction of ERs with co-activators or co-repressors and hence determines ER binding to DNA and cellular outcomes. This information has helped to shed light on the connection between E2 and the development or progression of numerous diseases. Current therapeutic strategy in the treatment of E2-related pathologies relies on the modulation of ER trancriptional activity by anti-estrogens; however, data accumulated during the last five years reveal that ER activities are not only restricted to the nucleus. ERs are very mobile proteins continuously shuttling between protein targets located within various cellular compartments (e.g., membrane, nucleus). This allows E2 to generate different and synergic signal transduction pathways (i.e., non-genomic and genomic) which provide plasticity for cell response to E2. Understanding the structural basis and the molecular mechanisms by which ER transduce E2 signals in target cells will allow to create new pharmacologic therapies aimed at the treatment of a variety of human diseases affecting the cardiovascular system, the reproductive system, the skeletal system, the nervous system, the mammary gland, and many others.

Progressive increase of SCCA-IgM immune complexes in cirrhotic patients is associated with development of hepatocellular carcinoma

About 3-4% of cirrhotic patients develop primary liver cancer every year. Specific serologic markers have not yet been identified for screening of high risk patients. The serpin squamous cell carcinoma antigen (SCCA) is overexpressed in liver cancer and circulating SCCA-IgM complexes have been described in patients with hepatocellular carcinoma (HCC). The aim of the present study was to assess the behavior of SCCA-IgM in relation to HCC development in patients with cirrhosis. A retrospective, longitudinal study was conducted in a cohort of prospectively followed cirrhotic patients. Two groups with similar clinical profile at presentation were studied : group A included 16 patients who developed HCC during a median follow up of 4 years; group B included 17 patients who did not develop HCC during the same time interval. Circulating SCCA-IgM immune complexes were determined using a recently standardized ELISA assay. At presentation similar levels of SCCA-IgM complexes [mean +/- SD: 267.40 +/- 382.25 U/ml vs. 249.10 +/- 446.90 U/ml, p = 0.9006] and of alpha-fetoprotein [AFP; 24.11 +/- 59.04 IU/ml vs. 10.91 +/- 23.34 IU/ml, p = 0.3995] were detected in group A and in group B. The increase over time (phi) of SCCA-IgM, assessed within at least one year before clinical diagnosis of HCC, was remarkably higher in group A than in group B (mean +/- SD = 280.05 +/- 606.71 (U/ml)/year vs. -37.92 +/- 95.94 (U/ml)/year, p = 0.0408), while AFP increase was not significantly different (11.89 +/- 23.27 (IU/ml)/year vs. 3.67 +/- 11.46 (IU/ml)/year, p = 0.2179). Receiver operating characteristic (ROC) curves were plotted for the rate of change in the levels of both markers and the diagnostic accuracy measured as AUROC was higher for SCCA-IgM phi (0.821) than for AFP phi (0.654). In conclusion, the progressive increase of SCCA-IgM over time was associated with liver tumor development, suggesting that monitoring the behavior of SCCA-IgM might become useful to identify cirrhotic patients at higher risk of HCC development.

Lead and cadmium in meat and meat products consumed by the population in Tenerife Island, Spain

The aim of this study was to determine the levels of lead and cadmium in chicken, pork, beef, lamb and turkey samples (both meat and meat products), collected in the island of Tenerife (Spain). Lead and cadmium were measured by graphite furnace atomic absorption spectrometry (GFAAS). Mean concentrations of lead and cadmium were 6.94 and 1.68 microg kg(-1) in chicken meat, 5.00 and 5.49 microg kg(-1) in pork meat, 1.91 and 1.90 microg kg(-1) in beef meat and 1.35 and 1.22 microg kg(-1) in lamb meat samples, respectively. Lead was below the detection limit in turkey samples and mean cadmium concentration was 5.49 microg kg(-1). Mean concentrations of lead and cadmium in chicken meat product samples were 3.16 and 4.15 microg kg(-1), 4.89 and 6.50 microg kg(-1) in pork meat product, 6.72 and 4.76 microg kg(-1) in beef meat product and 9.12 and 5.98 microg kg(-1) in turkey meat product samples, respectively. The percentage contribution of the two considered metals to provisional tolerable weekly intake (PTWI) was calculated for meat and meat products. Statistically significant differences were found for lead content in meats between the chicken and pork groups and the turkey and beef groups, whereas for cadmium concentrations in meats, significant differences were observed between the turkey and chicken, beef and lamb groups. In meat products, no clear differences were observed for lead and cadmium between the various groups.

A questionnaire survey on the management of Graves' orbitopathy in Europe

OBJECTIVE

To determine management patterns among clinicians who treat patients with Graves' orbitopathy (GO) in Europe.

DESIGN AND METHODS

Questionnaire survey including a case scenario of members of professional organisations representing endocrinologists, ophthalmologists and nuclear medicine physicians.

RESULTS

A multidisciplinary approach to manage GO was valued by 96.3% of responders, although 31.5% did not participate or refer to a multidisciplinary team and 21.5% of patients with GO treated by responders were not managed in a multidisciplinary setting. Access to surgery for sight-threatening GO was available only within weeks or months according to 59.5% of responders. Reluctance to refer urgently to an ophthalmologist was noted by 32.7% of responders despite the presence of suspected optic neuropathy. The use of steroids was not influenced by the age of the patient, but fewer responders chose to use steroids in a diabetic patient (72.1 vs 90.5%, P<0.001). Development of cushingoid features resulted in a reduction in steroid use (90.5 vs 36.5%, P<0.001) and increase in the use of orbital irradiation (from 23.8% to 40.4%, P<0.05) and surgical decompression (from 20.9 to 52.9%, P<0.001). More ophthalmologists chose surgical decompression for patients with threatened vision due to optic neuropathy, who were intolerant to steroids than other specialists (70.3 vs 41.8%, P<0.01).

CONCLUSION

Deficiencies in the management of patients with GO in Europe were identified by this survey. Further training of clinicians, easier access of patients to specialist multidisciplinary centres and the publication of practice guidelines may help improve the management of this condition in Europe.

Neurophysiological and mitochondrial abnormalities in MuSK antibody seropositive myasthenia gravis compared to other immunological subtypes

OBJECTIVE

To compare the electrophysiological and histopathological features of immunological myasthenia gravis (MG) subtypes.

METHODS

Fifty MG patients underwent clinical examination, MuSK-Ab and AChR-Ab analysis. The majority underwent quantitative and single-fiber electromyography (QEMG, SFEMG), repetitive nerve stimulation and deltoid muscle biopsy. From muscle specimens with histological mitochondrial dysfunction, we amplified mitochondrial DNA (mtDNA). In specimens with mtDNA deletions, the nuclear gene POLG1 was sequenced.

RESULTS

Five AChR-Ab seropositive [AChR(+)] and 5 seronegative [AChR(-)] patients were MuSK-Ab seropositive [MuSK(+)]. Five of 7 neurophysiologically examined MuSK(+) patients (71%) had proximal myopathic pattern, compared to 7 of 31 MuSK(-)/AChR(+) patients (23%) (P=0.012). SFEMG was abnormal in all examined MuSK(+) patients. All 7 biopsied MuSK(+) and 32 MuSK(-) patients (89%) had cytochrome c oxidase (COX) negative fibers. Three of five MuSK(+) and 13 of 20 MuSK(-) patients analyzed had multiple mtDNA deletions but no POLG1 mutations.

CONCLUSIONS

Similar degree of SFEMG abnormalities was present in proximal muscles among MuSK(+) and AChR(+) patients. Proximal myopathy was over-represented in MuSK(+) patients; however, both MuSK(+) and MuSK(-) patients had mild myopathy with frequent mitochondrial abnormalities.

SIGNIFICANCE

The weakness in MuSK(+) patients is most likely due to disturbed neuromuscular transmission. The frequently encountered mitochondrial dysfunction in MG warrants further study.

Mutation rates at Y chromosome specific microsatellites

A collaborative work was carried out by the Spanish and Portuguese ISFG Working Group (GEP-ISFG) to estimate Y-STR mutation rates. Seventeen Y chromosome STR loci (DYS19, DYS385, DYS389I and II, DYS390, DYS391, DYS392, DYS393, DYS437, DYS438, DYS439, DYS460, DYS461, DYS635 [GATA C4], GATA H4, and GATA A10) were analyzed in a sample of 3,026 father/son pairs. Among 27,029 allele transfers, 54 mutations were observed, with an overall mutation rate across the 17 loci of 1.998 x 10(-3) (95% CI, 1.501 x 10(-3) to 2.606 x 10(-3)). With just one exception, all of the mutations were single-step, and they were observed only once per gametogenesis. Repeat gains were more frequent than losses, longer alleles were found to be more mutable, and the mutation rate seemed to increase with the father's age. Hum Mutat 26(6), 520-528, 2005. (c) 2005 Wiley-Liss, Inc.

Mitochondrial mutation detection using enhanced multiplex denaturing high-performance liquid chromatography

In this study, we investigated the presence of mutations within the mitochondrial genome in 40 Caucasian subjects using an enhanced multiplex denaturing high-performance liquid chromatography (DHPLC) approach. The enhanced DHPLC approach has increased sensitivity and throughput, and reduced analysis time per individual sample compared to conventional methods. This technique involved amplifying the mitochondrial genome in 18 fragments ranging in size from 300 to 2000 bp using a novel proofreading polymerase (Optimase, Transgenomic Inc., Omaha, NE) with a low misincorporation rate. Fourteen of these fragments underwent subsequent restriction digestion using a combination of five restriction enzymes to enable multiplex DHPLC analysis; the remaining four underwent conventional DHPLC. Using this complete mitochondrial genome-screening approach, we confirmed a number of previously reported mutations and additionally identified a large number of novel mutations using an enhanced DHPLC technique.

Diffuse large B-cell lymphoma involving the breast. A report of four cases

Non-Hodgkin lymphoma of the breast is an uncommon form of lymphoma occurring either primary disease (PBL) or part of systemic involvement. We report the clinical outcome of 4 consecutive cases with CD20+ diffuse large B-cell lymphoma (DLBCL) of the breast, in the attempt to further clarify the management of this disease. The median age was 53 years (39-61), stages were IIE (n=2), IIIE (n=1), and IV (n=1); IPI scores were 0 (n=2), 2 (n=2). Two cases were PBL, and 2 were secondary involvement of the breast. Two stage IIE patients received MACOP-B, radiation therapy was given to one of them and both achieved CR. The stage IIIE patient treated with MACOP-B plus Rituximab was in PR at the beginning of the Rituximab and achieved CR at the end of the treatment. The 61-year-old stage IV patient and bilateral involvement received P-VNBEC as first line treatment, achieving PR; she was then treated with 4 cycles of MACOP-B plus Rituximab obtaining CR. After a median follow-up of 40 months (31-50) all patients are alive and in CR. No CNS prophylaxis was given and no incidence of CNS relapse was observed. In our experience DLBCL of the breast shows chemosensitivity to MA-COP-B regimen but the intensification with Rituximab seems to be effective especially in the advanced stages. Further and comparative studies are required to confirm the validity of our results.

Nitric oxide impairs the 17beta-estradiol-induced apoptosis in human colon adenocarcinoma cells

Nitric oxide (NO) and 17beta-estradiol (E2) are both important in gastrointestinal health and disease. NO contributes to gastrointestinal motility as well as to inflammation and carcinogenic processes. By contrast, E2 reduces the incidence of colon adenoma and carcinoma by about 30%. We report the genomic and non-genomic E2-estrogen receptor (ER) beta-induced effects in human colon adenocarcinoma. The effect of NO on ERbeta activities was also assessed. The E2-ERbeta-dependent gene transcription was inhibited by exogenous NO, whereas some non-genomic E2-dependent effects (e.g. p38/MAP kinase), important for the activation of the apoptotic cascade, were unaffected by NO. However, NO impaired the E2-induced pro-apoptotic cascade in human colon adenocarcinoma cells by inhibiting caspase-3. The effects of NO may reflect chemical modification(s) of Cys residues present in the DNA recognition domain of ERbeta as well as in the caspase-3 active site. On the whole, high NO concentrations suppressed the E2 protective effects in the gastrointestinal tract, suggesting that the caspase-dependent apoptotic cascade may become critical under conditions of high redox stress such as occur under specific activation of the immune system by chronic infections or pathogen challenge.

Detection of circulating CEA-IgM complexes in early stage colorectal cancer

We have recently shown that alpha fetoprotein (AFP) and squamous cell carcinoma antigen (SCCA), biomarkers associated with hepatocellular carcinoma, may be detected in patient sera as circulating immune complexes with IgM, and that assessment of serum levels of AFP-IgM and SCCA-IgM may be used for the detection of liver cancer. In this study we measured the levels of carcinoembryonic antigen (CEA) as free form (FCEA) and complexed to IgMs (CEA-IgM) in sera of patients affected by colorectal carcinoma (CRC) at different stages as well as in healthy subjects. FCEA levels were above the 5 ng/mL cutoff in 43% of CRC patients (31/72) and CEA-IgM levels were above the 200 AU/mL cutoff in 38% of CRC patients (27/72). Serum levels of CEA-IgM immune complexes (IC) and FCEA did not overlap and 64% of patients (46/72) were positive for at least one marker without compromising the detection specificity (94%). Early detection of CRC was significantly improved by CEA-IgM IC assay. CRC patients at an early stage (stage 1) had elevated CEA-IgM levels in 29% of cases (7/24), while FCEA levels were elevated in only 8% of cases (2/24). These results indicate that CEA-IgM is a complementary serological marker to FCEA which is much more sensitive for early stage CRC, and that the combination of these biomarkers may be useful in the early detection of colorectal cancer.

S-palmitoylation modulates estrogen receptor alpha localization and functions

17beta-Estradiol (E2) acts as a chemical messenger in target tissues inducing both slow nuclear and rapid extra-nuclear responses. E2 binds to its cognate nuclear receptors (ER) resulting in the activation of target gene transcription in the nucleus. In addition to these genomic effects, E2 modulates cell functions through rapid non-genomic actions. Stimulation of G-proteins, Ca(2+) influx, inositol phosphate generation as well as phospholipase C, ERK/MAPK, and PI3K/AKT activation all occur within seconds to minutes after E2 binding to a small population of ERalpha located at the plasma membrane. The great impact of these rapid signals on cell physiology renders central the knowledge of the structural bases and mechanisms that mediate extra-nuclear signaling by E2. Several laboratories, including our own, have recently elucidated the structural requirements for localization and function of plasma membrane ERalpha. This review summarizes the molecular mechanisms of E2-induced rapid non-genomic actions relevant for cell functions, highlighting the role of lipid modification (i.e., palmitoylation) in the ERalpha localization to and residence at the plasma membrane.

Traumatic carotid cavernous fistula: failure of endovascular treatment with two stent-grafts

SUMMARY

We describe an unconventional endovascular approach in a young patient with large highflow traumatic carotid cavernous fistula that could not be treated by detachable balloon procedure. Two coronary stent-grafts were used to close the large tear of internal carotid artery. After the failure of stenting procedure, the fistula was successfully treated by trapping with two detachable balloons.

c-MYC deregulation is involved in melphalan resistance of multiple myeloma: role of PDGF-BB

Oncogenes are important regulators of cancer growth and progression and their action may be modulated by proteins of the growth factor family, such as angiogenic cytokines, known to be strongly involved in neoplastic evolution. Reciprocal interactions between oncogenes and angiogenic modulators may represent, in haematological neoplasms, including multiple myeloma (MM), a possible mechanism of drug resistance. The aim of this work is to investigate in vitro and in vivo whether or not c-myc deregulation is involved in the melphalan resistance elicited by myeloma patients and consequently to clarify the role of the angiogenic factor PDGF-BB in modulating c-myc protein expression. Fifty-one MM patients on chemotherapy with melphalan were analyzed for structural alterations of the c-myc gene, c-Myc protein expression, as well as for serum PDGF-BB release. For the in vitro study, two M14-derived established cell clones, differing for the c-Myc protein expression (c-Myc low -expressing or constitutively expressing clones) were used. Our results show that PDGF-BB is able to up-regulate Myc expression and reduce melphalan sensitivity of tumor cell clones, constitutively expressing c-myc gene product. In addition, down-regulation of c-Myc protein induces the expression of PDGF-beta receptor molecules and reduces PDGF-BB release. In agreement with these results, in vivo data show that melphalan-resistant MM patients present overexpressed c-Myc protein and higher serum PDGF-BB receptor levels compared to minor responding patients.

Estrogen signaling multiple pathways to impact gene transcription

Steroid hormones exert profound effects on cell growth, development, differentiation, and homeostasis. Their effects are mediated through specific intracellular steroid receptors that act via multiple mechanisms. Among others, the action mechanism starting upon 17beta-estradiol (E2) binds to its receptors (ER) is considered a paradigmatic example of how steroid hormones function. Ligand-activated ER dimerizes and translocates in the nucleus where it recognizes specific hormone response elements located in or near promoter DNA regions of target genes. Behind the classical genomic mechanism shared with other steroid hormones, E2 also modulates gene expression by a second indirect mechanism that involves the interaction of ER with other transcription factors which, in turn, bind their cognate DNA elements. In this case, ER modulates the activities of transcription factors such as the activator protein (AP)-1, nuclear factor-kappaB (NF-kappaB) and stimulating protein-1 (Sp-1), by stabilizing DNA-protein complexes and/or recruiting co-activators. In addition, E2 binding to ER may also exert rapid actions that start with the activation of a variety of signal transduction pathways (e.g. ERK/MAPK, p38/MAPK, PI3K/AKT, PLC/PKC). The debate about the contribution of different ER-mediated signaling pathways to coordinate the expression of specific sets of genes is still open. This review will focus on the recent knowledge about the mechanism by which ERs regulate the expression of target genes and the emerging field of integration of membrane and nuclear receptor signaling, giving examples of the ways by which the genomic and non-genomic actions of ERs on target genes converge.

BioEnterics Intragastric Balloon: The Italian Experience with 2,515 Patients

BACKGROUND

The temporary use of the BioEnterics Intragastric Balloon (BIB) in morbidly obesity is increasing worldwide. The aim of this study is the evaluation of the efficacy of this device in a large population, in terms of weight loss and its influence on co-morbidities.

METHODS

Data were retrospectively recruited from the data-base of the Italian Collaborative Study Group for Lap-Band and BIB (GILB). After diagnostic endoscopy, the BIB was positioned and was filled with saline (500-700 ml) and methylene blue (10 ml). Patients were discharged with diet counselling ( approximately 1000 Kcal) and medical therapy. The BIB was removed after 6 months. Positioning and removal were performed under conscious or unconscious sedation. Mortality, complications, BMI, %EWL, BMI loss and co-morbidities were evaluated.

RESULTS

From May 2000 to September 2004, 2,515 patients underwent BIB (722M/1,793F; mean age 38.9+/-14.7, range 12-71; mean BMI 44.4+/-7.8 kg/m(2) ; range 28.0-79.1; and mean excess weight 59.5+/-29.8 kg, range 16-210). BIB positioning was uncomplicated in all but two cases (0.08%) with acute gastric dilation treated conservatively. Overall complication rate was 70/2,515 (2.8%). Gastric perforation occurred in 5 patients (0.19%), 4 of whom had undergone previous gastric surgery: 2 died and 2 were successfully treated by laparoscopic repair after balloon removal. 19 gastric obstructions (0.76%) presented in the first week after positioning and were successfully treated by balloon removal. Balloon rupture (n=9; 0.36%) was not prevalent within any particular period of BIB treatment, and was also treated by BIB removal. Esophagitis (n=32; 1.27%) and gastric ulcer (n=5; 0.2%) presented in patients without a history of peptic disease and were treated conservatively by drugs. Preoperative co-morbidities were diagnosed in 1,394/2,471 patients (56.4%); these resolved in 617/1,394 (44.3%), improved (less pharmacological dosage or shift to other therapies) in 625/1,394 (44.8%), and were unchanged in 152/1,394 (10.9%). After 6 months, mean BMI was 35.4+/-11.8 kg/m(2) (range 24-73) and %EWL was 33.9+/-18.7 (range 0-87). BMI loss was 4.9+/-12.7 kg/m(2) (range 0-25).

CONCLUSIONS

BIB is an effective procedure with satisfactory weight loss and improvement in co-morbidities after 6 months. Previous gastric surgery is a contraindication to BIB placement.

Daidzein-sulfate metabolites affect transcriptional and antiproliferative activities of estrogen receptor-beta in cultured human cancer cells

Daidzein (D), a soy isoflavone, is almost completely metabolized in the gut and liver. This biotransformation converts D to more water-soluble products and may affect its biological activity. The ability of daidzein metabolites to modulate 17beta-estradiol (E2)-sensitive gene transcription, cell growth, and a proapoptotic cascade was determined in human cancer cells devoid of any estrogen receptor (ER) and rendered E2 sensitive after transfection with ERbeta. The data show that D and some but not all of its metabolites 1) induce promoter activity, 2) reduce proliferation, 3) promote p38/mitogen-activated protein kinase (MAPK) phosphorylation, and 4) activate a proapoptotic cascade involving the cleavage of caspase-3 and its substrate poly(ADP-ribose)polymerase (PARP) in human cancer cells in an ERbeta-dependent manner. Pretreatment of cells with ICI 182,780, a pure antiestrogen, completely prevented the actions of D and its metabolites. These findings highlight the important and complex influence of metabolic transformation on key physiological effects of isoflavones and demonstrate the need to take biotransformation into account when assessing the potential health benefits of consuming soy isoflavones.

Estrogen receptor signalling: bases for drug actions

Estrogen receptors (ERalpha and ERbeta) mediate the effects of 17beta-estradiol (E2) and account for E2 role on growth, development, and homeostasis maintenance in different tissues and organs. ERalpha and ERbeta function as ligand-dependent transcription factors which directly bind to specific estrogen responsive element (ERE) present into DNA and, in turn, regulate the transcription of E2-sensitive genes. In addition, ERalpha and ERbeta, without direct binding to DNA, regulate transcription indirectly by binding to other transcription factors activating or inactivating the transcription of E2-dependent-ERE-devoid genes. Along with these two E2 mechanisms, it has been recently uncovered that a third signalling pathway, involving cytoplasmic proteins and rapid membrane-initiated responses, serves largely for mitogenic E2-induced effects. The commitment of ERbeta in these rapid E2-induced effects is openly debated. This review will focus and summarize the latest findings regarding the multiple E2 molecular mechanisms and underlines the development of our understanding of anti-cancer drugs acting as ER signalling modulators.

Squamous cell carcinoma antigen-immunoglobulin M complexes as novel biomarkers for hepatocellular carcinoma

BACKGROUND

Early detection of hepatocellular carcinoma (HCC), one of the most common and deadly tumors worldwide, still is difficult due to the lack of adequate biomarkers that show high sensitivity and specificity. The authors recently demonstrated that squamous cell carcinoma antigen (SCCA) variants were overexpressed remarkably in all surgically resected HCCs.

METHODS

For the current study, the authors assessed the presence of SCCA, as a free form and complexed with immunoglobulins, in serum from patients with HCC, cirrhosis, and chronic hepatitis and from healthy control participants and compared SCCA measurement with the measurement of alpha-fetoprotein (AFP) levels.

RESULTS

Circulating immune complexes (ICs) composed by SCCA and immunoglobulin M (IgM) IC (SCCA-IgM IC) were undetectable (< 120 arbitrary units [AU]/mL) in serum from a healthy control population (0 of 73 controls); however, 35 of 50 patients with HCC (70%) were reactive for SCCA-IgM IC independent of etiology (mean +/- standard deviation [SD], 2568.5 +/- 6797.3 AU/mL). No correlation was found with AFP levels, which were elevated significantly in only 21 of 50 patients with HCC (42%). By using an AFP cut-off value of 20 ng/mL, 96% of patients with HCC were positive for at least 1 marker. Among cirrhotic patients, the presence of circulating SCCA-IgM IC was displayed in 13 of 50 patients (26%), but at lower levels compared with the patients who had HCC (mean +/- SD, 147.5 +/- 348.3 AU/mL; P < 0.01; Student t test), whereas 9 of 50 patients with chronic hepatitis (18%) were reactive (mean +/- SD, 39.5 +/- 89.7 AU/mL). No significant presence of free SCCA, free anti-SCCA variants IgG or IgM, or SCCA-IgG IC was found.

CONCLUSIONS

The study results indicated that SCCA-IgM ICs represent novel serologic biomarkers, which, alone or in combination with AFP, can increase the sensitivity for diagnosing HCC significantly.