Adenosine deaminase activity in patients with ovarian neoplasms

Nanoparticles targeting the adenosine pathway for cancer immunotherapy

Cancer immunotherapy, as an emerging approach to cancer treatment, has tremendous potential for application. Compared to traditional methods such as surgery, chemotherapy, and radiation therapy, it has the ability to restore the patient's immune system, leading to long-term immune memory with less damage to normal tissues. However, immunotherapy has its limitations, including limited therapeutic efficacy, restricted patient populations, and inconsistent treatment responses. Finding effective immunotherapeutic approaches has become a key focus of its clinical application. The adenosine pathway is a recently discovered tumor immune regulatory signaling pathway. It can influence the metabolism and growth of tumor cells by acting through key enzymes in the adenosine pathway, thereby affecting the development of tumors. Therefore, inhibiting the adenosine pathway is an effective cancer immunotherapy. Common adenosine pathway inhibitors include small molecules and antibody proteins, and extensive preclinical trials have demonstrated their effectiveness in inhibiting tumor growth. The short half-life, low bioavailability, and single administration route of adenosine pathway inhibitors limit their clinical application. With the advent of nanotechnology, nano-delivery of adenosine pathway inhibitors has addressed these issues. Compared to traditional drugs, nano-drugs extend the drug's circulation time and improve its distribution within the body. They also offer targeting capabilities and have low toxic side effects, making them very promising for future applications. In this review, we discuss the mechanism of the adenosine pathway in tumor immune suppression, the clinical applications of adenosine pathway inhibitors, and nano-delivery based on adenosine pathway inhibitors. In the final part of this article, we also briefly discuss the technical issues and challenges currently present in nano-delivery of adenosine pathway inhibitors, with the hope of advancing the progress of adenosine inhibitor nano-drugs in clinical treatment.

Early Ovarian Cancer Detection in the Age of Fallopian Tube Precursors: A Systematic Review

OBJECTIVE

To determine biomarkers other than CA 125 that could be used in identifying early-stage ovarian cancer.

DATA SOURCES

Ovid MEDLINE ALL, EMBASE, Web of Science Core Collection, ScienceDirect, Clinicaltrials.gov , and CAB Direct were searched for English-language studies between January 2008 and April 2023 for the concepts of high-grade serous ovarian cancer, testing, and prevention or early diagnosis.

METHODS OF STUDY SELECTION

The 5,523 related articles were uploaded to Covidence. Screening by two independent reviewers of the article abstracts led to the identification of 245 peer-reviewed primary research articles for full-text review. Full-text review by those reviewers led to the identification of 131 peer-reviewed primary research articles used for this review.

TABULATION, INTEGRATION, AND RESULTS

Of 131 studies, only 55 reported sensitivity, specificity, or area under the curve (AUC), with 36 of the studies reporting at least one biomarker with a specificity of 80% or greater specificity or 0.9 or greater AUC.

CONCLUSION

These findings suggest that although many types of biomarkers are being tested in ovarian cancer, most have similar or worse detection rates compared with CA 125 and have the same limitations of poor detection rates in early-stage disease. However, 27.5% of articles (36/131) reported biomarkers with better sensitivity and an AUC greater than 0.9 compared with CA 125 alone and deserve further exploration.

Impact of gallic acid on tumor suppression: Modulation of redox homeostasis and purinergic response in in vitro and a preclinical glioblastoma model

Glioblastoma (GBM) is the deadliest primary brain tumor in adults due to the high rate of relapse with current treatment. Therefore, the search for therapeutic alternatives is urgent. Gallic acid (GA), a potent natural antioxidant, has antitumor and modulatory actions on purinergic signaling. In this study, we investigated the cytotoxic effects of GA on the rat GBM (C6) cell line and on astrocyte culture and analyzed its role in regulating oxidative stress and purinergic enzymes involved in GBM proliferation. Cells were exposed to GA from 50 to 400 µM for 24 and/or 48 h. Next, the effect of GA was evaluated in the preclinical model of GBM. Wistar rats were treated with 50 or 100 mg/kg of GA for 15 days, and cerebral and systemic redox status and degradation of adenine nucleotides and nucleosides in circulating platelets, lymphocytes, and serum were evaluated. Our results demonstrated that GA has selective anti-glioma activity in vitro, without inducing cytotoxicity in astrocyte. Furthermore, GA prevented oxidative stress and changes in the hydrolysis of nucleotides in GBM cells. The anti-glioma effect was also observed in vivo, as GA reduced tumor volume by 90%. Interestingly, GA decreased the oxidative damage induced by a tumor in the brain, serum, and platelets, and, also prevented changes in the degradation of nucleotides and nucleosides in lymphocytes, platelets, and serum. These results indicate, for the first time, the therapeutic potential of GA in a preclinical model of GBM, whose effects may be related to its role in redox and purinergic modulation.

Inhibiting DNA methylation and RNA editing upregulates immunogenic RNA to transform the tumor microenvironment and prolong survival in ovarian cancer

BACKGROUND

Novel therapies are urgently needed for ovarian cancer (OC), the fifth deadliest cancer in women. Preclinical work has shown that DNA methyltransferase inhibitors (DNMTis) can reverse the immunosuppressive tumor microenvironment in OC. Inhibiting DNA methyltransferases activate transcription of double-stranded (ds)RNA, including transposable elements. These dsRNAs activate sensors in the cytoplasm and trigger type I interferon (IFN) signaling, recruiting host immune cells to kill the tumor cells. Adenosine deaminase 1 (ADAR1) is induced by IFN signaling and edits mammalian dsRNA with an A-to-I nucleotide change, which is read as an A-to-G change in sequencing data. These edited dsRNAs cannot be sensed by dsRNA sensors, and thus ADAR1 inhibits the type I IFN response in a negative feedback loop. We hypothesized that decreasing ADAR1 editing would enhance the DNMTi-induced immune response.

METHODS

Human OC cell lines were treated in vitro with DNMTi and then RNA-sequenced to measure RNA editing. Adar1 was stably knocked down in ID8 Trp53^-/- mouse OC cells. Control cells (shGFP) or shAdar1 cells were tested with mock or DNMTi treatment. Tumor-infiltrating immune cells were immunophenotyped using flow cytometry and cell culture supernatants were analyzed for secreted chemokines/cytokines. Mice were injected with syngeneic shAdar1 ID8 Trp53^-/- cells and treated with tetrahydrouridine/DNMTi while given anti-interferon alpha and beta receptor 1, anti-CD8, or anti-NK1.1 antibodies every 3 days.

RESULTS

We show that ADAR1 edits transposable elements in human OC cell lines after DNMTi treatment in vitro. Combining ADAR1 knockdown with DNMTi significantly increases pro-inflammatory cytokine/chemokine production and sensitivity to IFN-β compared with either perturbation alone. Furthermore, DNMTi treatment and Adar1 loss reduces tumor burden and prolongs survival in an immunocompetent mouse model of OC. Combining Adar1 loss and DNMTi elicited the most robust antitumor response and transformed the immune microenvironment with increased recruitment and activation of CD8+ T cells.

CONCLUSION

In summary, we showed that the survival benefit from DNMTi plus ADAR1 inhibition is dependent on type I IFN signaling. Thus, epigenetically inducing transposable element transcription combined with inhibition of RNA editing is a novel therapeutic strategy to reverse immune evasion in OC, a disease that does not respond to current immunotherapies.

Targeting purine metabolism in ovarian cancer

Purine, an abundant substrate in organisms, is a critical raw material for cell proliferation and an important factor for immune regulation. The purine de novo pathway and salvage pathway are tightly regulated by multiple enzymes, and dysfunction in these enzymes leads to excessive cell proliferation and immune imbalance that result in tumor progression. Maintaining the homeostasis of purine pools is an effective way to control cell growth and tumor evolution, and exploiting purine metabolism to suppress tumors suggests interesting directions for future research. In this review, we describe the process of purine metabolism and summarize the role and potential therapeutic effects of the major purine-metabolizing enzymes in ovarian cancer, including CD39, CD73, adenosine deaminase, adenylate kinase, hypoxanthine guanine phosphoribosyltransferase, inosine monophosphate dehydrogenase, purine nucleoside phosphorylase, dihydrofolate reductase and 5,10-methylenetetrahydrofolate reductase. Purinergic signaling is also described. We then provide an overview of the application of purine antimetabolites, comprising 6-thioguanine, 6-mercaptopurine, methotrexate, fludarabine and clopidogrel. Finally, we discuss the current challenges and future opportunities for targeting purine metabolism in the treatment-relevant cellular mechanisms of ovarian cancer.

ELISA based assays to measure adenosine deaminases concentration in serum and saliva for the diagnosis of ADA2 deficiency and cancer

Adenosine deaminases (ADAs) are enzymes of purine metabolism converting adenosine to inosine. There are two types of ADAs in humans ADA1 and ADA2. While both ADA1 and ADA2 share the same substrate, they differ in expression, cellular localization, and catalytic properties. The genetic deficiency of ADA1 results in severe combined immunodeficiency (SCID), while lack in ADA2 (DADA2) results in multiple phenotypes ranging from systemic inflammation to vascular pathology. Clinical studies have shown that the levels of ADAs in biological fluids are altered in pathophysiological conditions, suggesting that ADA activity could be a convenient marker for the diagnosis of immune diseases and cancer. Here, we describe sensitive and straightforward ELISA assays to measure ADA1 and ADA2 concentrations in biological fluids. Analysis of the serum and saliva samples from the healthy controls and DADA2 patients revealed that ADA2 enzyme concentration is significantly lower in patients than in healthy controls. In contrast, the concentration of ADA2 increases in the serum of patients with large granular leukocyte leukemia (LGLL) and patients’ saliva with head and neck cancer. Thus, this simple, non-invasive method allows for distinguishing healthy controls from the affected patient. It can be implemented in screening and diagnosis of DADA2 and follow up the treatment of LGLL and several types of head and neck cancer.

Diagnostic value of adenosine deaminase in bronchoalveolar lavage fluid for patients with lung cancer

BACKGROUND

Lung cancer is both the most common seen malignity and cause of cancer-related deaths worldwide. Adenosine deaminase (ADA) is a hydrolytic enzyme that catalyses the conversion of adenosine to inosine in the purine metabolism pathway. Studies examining ADA levels in bronchoalveolar lavage (BAL) fluids of patients with lung malignancy are very limited in the literature. Our aim examine the clinical significance of ADA levels in BAL fluids of patients with lung malignancy.

METHODS

A total of 89 patients undergoing fiberoptic bronchoscopy (FOB) with different indications from December 2017 to December 2018 were included in this study. The patients were divided into two groups as malignancy and non-malignancy groups. Demographic, laboratory data and ADA levels in bronchoalveolar lavage (BAL) were compared between the two groups. In addition, ADA levels in BAL were compared among the histopathological subtypes of patients in the malignant group.

RESULTS

The mean age of the patients was 58.2 ± 14.5 years with 86% of male gender. ADA enzyme levels were statistically higher in the malignant patient group compared with the non-malignant group (37.2 [17.6-71] vs 17.1 [9-35.3], P < .001). When the patients in the malignant group were compared in terms of ADA levels according to their histopathological types, a statistically significant difference was obtained in small cell carcinoma patients (49 [12.5-75.3], P = .005).

CONCLUSION

ADA levels in BAL may be a diagnostic biomarker in lung malignancies. In patients where a biopsy cannot be taken or histopathological typing cannot be performed because of tissue insufficiency, ADA levels in BAL can be an auxiliary parameter in making malignancy / histopathological diagnosis accompanied by radiological and clinical findings.

Utility of Ascitic Fluid Adenosine Deaminase Levels in the Diagnosis of Tuberculous Peritonitis in General Medical Practice

Background

Tuberculous peritonitis is difficult to diagnose due to its varying clinical features, in addition to the low yield on bacterial culture or polymerase chain reaction using ascitic fluid samples. This study aimed to investigate the sensitivity and specificity of elevated adenosine deaminase (ADA) levels as a diagnostic marker for tuberculous peritonitis.

Methods

A retrospective cohort of 181 adult patients who underwent ascitic fluid ADA level examination at Jichi Medical University Hospital between January 2006 and December 2015 were included. We collected data regarding ascitic fluid analyses including ADA levels, bacteriology and cytology, final diagnosis (cause of ascites), basis of the diagnosis, duration to diagnosis, and disease outcome.

Results

Among 181 patients, elevated ascitic ADA levels (≥40 IU/L) were observed in 15 patients (median, 87.2 IU/L; range, 44.0–176.1 IU/L); 8 patients had tuberculous peritonitis, 4 had lymphoma-related ascites, and 2,had peritoneal carcinomatosis with bacterial coinfection, and 1 had chlamydial pelvic inflammatory disease. Among 166 patients without ascitic ADA level elevation (median, 7.3 IU/L; range, <2.0–39.1 IU/L), none had tuberculosis, 4 had lymphoma-related ascites, 28 had cancer/mesothelioma-related ascites, and 134 had ascites due to other causes. In our cohort, elevated ascitic fluid ADA levels (≥40 IU/L) showed 100% sensitivity, 96.0% specificity, 53.3% positive predictive value (PPV), and 100% negative predictive value for the diagnosis of peritoneal tuberculosis.

Conclusions

Ascitic fluid ADA levels ≥40 IU/L showed excellent sensitivity, despite a low PPV, for the diagnosis of tuberculous peritonitis. Lymphoma-related ascites is an important mimic of tuberculous peritonitis that can result in high ascitic fluid ADA levels with similar clinical manifestations.

Purine-Metabolising Enzymes and Apoptosis in Cancer

The enzymes of both de novo and salvage pathways for purine nucleotide synthesis are regulated to meet the demand of nucleic acid precursors during proliferation. Among them, the salvage pathway enzymes seem to play the key role in replenishing the purine pool in dividing and tumour cells that require a greater amount of nucleotides. An imbalance in the purine pools is fundamental not only for preventing cell proliferation, but also, in many cases, to promote apoptosis. It is known that tumour cells harbour several mutations that might lead to defective apoptosis-inducing pathways, and this is probably at the basis of the initial expansion of the population of neoplastic cells. Therefore, knowledge of the molecular mechanisms that lead to apoptosis of tumoural cells is key to predicting the possible success of a drug treatment and planning more effective and focused therapies. In this review, we describe how the modulation of enzymes involved in purine metabolism in tumour cells may affect the apoptotic programme. The enzymes discussed are: ectosolic and cytosolic 5'-nucleotidases, purine nucleoside phosphorylase, adenosine deaminase, hypoxanthine-guanine phosphoribosyltransferase, and inosine-5'-monophosphate dehydrogenase, as well as recently described enzymes particularly expressed in tumour cells, such as deoxynucleoside triphosphate triphosphohydrolase and 7,8-dihydro-8-oxoguanine triphosphatase.

Prognostic value of serum liver enzymes in oral and oropharynx squamous cell carcinomas

BACKGROUND

Serum liver enzymes, which catalyze relevant catabolic pathways, have been indicated to be diagnostic and prognostic tools for several malignant tumors. The correlation between serum liver enzymes levels and survival in patients with oral and oropharynx squamous cell carcinomas (OSCC) is still absent. Here, we conducted a study focusing on predictive value of serum liver enzymes in terms of prognosis in the patients.

METHODS

A retrospective study including 134 OSCC patients from years 2009 to 2014 was performed to investigate the association between levels of pre-treatment serum liver enzymes, various clinical parameters and prognostic outcomes, which are overall survival (OS) and disease-free survival (DFS). Log-rank tests with Kaplan-Meier method were used to detect potential prognostic biomarkers. Multivariate analyses by Cox proportional hazards model were used to identify significant predictors of prognosis.

RESULTS

Serum adenosine deaminase (ADA) level was associated with patients' OS and DFS by univariate analyses (P = 0.006 and P = 0.024, respectively). Multivariate analyses showed that higher serum ADA (>17.2 U/L) (P = 0.019) as well as positive lymph node status (P = 0.035) independently predicted worse OS of patients with OSCC. In addition, older age (≥60 years) (P = 0.043) and positive lymph node status (P = 0.027) were independently prognostic parameters for poorer DFS.

CONCLUSIONS

Pre-operative serum ADA levels may serve as a reliable independent prognostic predictor for OS in OSCC patients.

Anticancer activity of methylene blue via inhibition of heat shock protein 70

INTRODUCTION

Heat shock protein 70 (Hsp70) and heat shock protein 90 (Hsp90) chaperones are indispensable to lung cancer cells for their survival and proliferation. In this study we evaluated and compared anticancer potential of methylene blue (MB) as an Hsp70 inhibitor, novobiocin (NB) a well-known Hsp90 inhibitor and their combination.

METHODS

In vitro evaluation was done by cell viability assays, fluorescent staining, and flow cytometry analysis using A549 non-small cell lung cancer cells. In vivo anticancer activity was investigated by evaluating oxidative stress, tumor biomarkers, weight, lung microarchitecture, and Hsp70 and Hsp90 inhibitions via immunoblotting in benzo[a]pyrene induced lung carcinogenesis mice model.

RESULTS

Using A549 NSCLC cells, we found MB demonstrated lower cell viability versus NB. Together, MB + NB resulted in further decrease in cell viability. SRB assay revealed significantly superior and similar potency for MB versus NB and MB + NB (1:1) versus MB, respectively. Fluorescent staining and flow cytometry analysis displayed early apoptosis by MB (11.4%); early and late apoptosis by MB + NB (13.8%). In vivo, MB significantly inhibited Hsp70. Furthermore, MB significantly alleviated tumor biomarkers (ADA and LDH) and improved lung histopathological features more than NB. Additionally, MB significantly improved SOD, not more than MB + NB or NB and improved LPO.

CONCLUSION

MB demonstrated potent anticancer activity in vitro and in vivo via inhibition of Hsp70 in benzo[a]pyrene induced lung carcinogenesis in mice.

Adenosine Deaminase 1 as a Biomarker for Diagnosis and Monitoring of Patients with Acute Lymphoblastic Leukemia

BACKGROUND

Acute lymphoblastic leukemia (ALL) is known as the most prevalent pediatric malignancy all around the world. Identification of specific biomarker is necessary for early diagnosis and effective therapy. It is believed that Adenosine deaminase (ADA) as an enzyme involved in the purine salvage pathway increases in ALL patients. Herein, the quantity and pattern of ADA isoenzymes were surveyed among ALL patients in comparison to healthy subjects.

METHODS

Serum and RBC samples of three different groups of ALL patients, including newly diagnosed cases without any drugs administration, subjects with the relapsed disease, patients in the remission stage after therapy, and the healthy subjects were enrolled in the study. Then, the activity and pattern of ADA1, ADA2 and ADA1+cp were determined using ADA kit and electrophoresis on SDS-PAGE, respectively. To confirm the presence of ADA enzyme, the fresh serums, extractions from erythrocytes, JM cell line as a human T lymphocyte line and J774 A.1 as mouse monocyte line were electrophoresed on 1.2% agarose gel and stained with the specific dye.

RESULTS

The activities of ADA1 isoenzyme and total ADA in new cases and subjects with the relapsed disease were significantly higher than their activities in the patients in the remission stage and healthy controls (p<0.001). The unbounded ADA1 isoenzyme was found to exist in the erythrocyte, lymphocyte and monocyte. But in serum, all the ADA1 was bounded to the cp protein.

CONCLUSIONS

ADA1 is the key isoenzyme elevating in ALL patients, therefore this isoenzyme could be a useful biomarker to diagnose ALL patients and monitor their therapies.

Sparse generalized linear model with L0 approximation for feature selection and prediction with big omics data

Background

Feature selection and prediction are the most important tasks for big data mining. The common strategies for feature selection in big data mining are L₁, SCAD and MC+. However, none of the existing algorithms optimizes L₀, which penalizes the number of nonzero features directly.

Results

In this paper, we develop a novel sparse generalized linear model (GLM) with L₀ approximation for feature selection and prediction with big omics data. The proposed approach approximate the L₀ optimization directly. Even though the original L₀ problem is non-convex, the problem is approximated by sequential convex optimizations with the proposed algorithm. The proposed method is easy to implement with only several lines of code. Novel adaptive ridge algorithms (L₀ADRIDGE) for L₀ penalized GLM with ultra high dimensional big data are developed. The proposed approach outperforms the other cutting edge regularization methods including SCAD and MC+ in simulations. When it is applied to integrated analysis of mRNA, microRNA, and methylation data from TCGA ovarian cancer, multilevel gene signatures associated with suboptimal debulking are identified simultaneously. The biological significance and potential clinical importance of those genes are further explored.

Conclusions

The developed Software L₀ADRIDGE in MATLAB is available at https://github.com/liuzqx/L0adridge.

Electronic supplementary material

The online version of this article (doi:10.1186/s13040-017-0159-z) contains supplementary material, which is available to authorized users.

Development of Adenosine Deaminase-Specific IgY Antibodies: Diagnostic and Inhibitory Application

Adenosine deaminase (ADA) is currently used as a diagnostic marker for tuberculous pleuritis. Although ADA has been suggested as a potential marker for several types of cancer, the importance of each of ADA isoforms as well as their levels and enzymatic activities in tumors need to be further investigated. Herein we developed avian immunoglobulin Y highly specific to human ADA via hens immunization with calf adenosine deaminase. The obtained antibodies were used for the development of a sensitive double-egg yolk immunoglobulin (IgY) sandwich ELISA assay with an ADA detection limit of 0.5 ng/ml and a linearity range of up to 10 ng/ml. Specific, affinity-purified IgYs were able to recognize human recombinant ADA and ADA present in human cancer cell lines. In addition, antigen-specific IgY antibodies were able to inhibit catalytic activity of calf ADA with an IC₅₀ value of 47.48 nM. We showed that generated IgY antibodies may be useful for ADA detection, thus acting as a diagnostic agent in immunoenzymatic assays.

Two-step polymer- and liposome-enzyme prodrug therapies for cancer: PDEPT and PELT concepts and future perspectives

Polymer-directed enzyme prodrug therapy (PDEPT) and polymer enzyme liposome therapy (PELT) are two-step therapies developed to provide anticancer drugs site-selective intratumoral accumulation and release. Nanomedicines, such as polymer-drug conjugates and liposomal drugs, accumulate in the tumor site due to extravasation-dependent mechanism (enhanced permeability and retention - EPR - effect), and further need to cross the cellular membrane and release their payload in the intracellular compartment. The subsequent administration of a polymer-enzyme conjugate able to accumulate in the tumor tissue and to trigger the extracellular release of the active drug showed promising preclinical results. The development of polymer-enzyme, polymer-drug conjugates and liposomal drugs had undergone a vast advancement over the past decades. Several examples of enzyme mimics for in vivo therapy can be found in the literature. Moreover, polymer therapeutics often present an enzyme-sensitive mechanism of drug release. These nanomedicines can thus be optimal substrates for PDEPT and this review aims to provide new insights and stimuli toward the future perspectives of this promising combination.

Inherited variants affecting RNA editing may contribute to ovarian cancer susceptibility: results from a large-scale collaboration

RNA editing in mammals is a form of post-transcriptional modification in which adenosine is converted to inosine by the adenosine deaminases acting on RNA (ADAR) family of enzymes. Based on evidence of altered ADAR expression in epithelial ovarian cancers (EOC), we hypothesized that single nucleotide polymorphisms (SNPs) in ADAR genes modify EOC susceptibility, potentially by altering ovarian tissue gene expression. Using directly genotyped and imputed data from 10,891 invasive EOC cases and 21,693 controls, we evaluated the associations of 5,303 SNPs in ADAD1, ADAR, ADAR2, ADAR3, and SND1. Unconditional logistic regression was used to estimate odds ratios (OR) and 95% confidence intervals (CI), with adjustment for European ancestry. We conducted gene-level analyses using the Admixture Maximum Likelihood (AML) test and the Sequence-Kernel Association test for common and rare variants (SKAT-CR). Association analysis revealed top risk-associated SNP rs77027562 (OR (95% CI)= 1.39 (1.17-1.64), P=1.0x10-4) in ADAR3 and rs185455523 in SND1 (OR (95% CI)= 0.68 (0.56-0.83), P=2.0x10-4). When restricting to serous histology (n=6,500), the magnitude of association strengthened for rs185455523 (OR=0.60, P=1.0x10-4). Gene-level analyses revealed that variation in ADAR was associated (P<0.05) with EOC susceptibility, with PAML=0.022 and PSKAT-CR=0.020. Expression quantitative trait locus analysis in EOC tissue revealed significant associations (P<0.05) with ADAR expression for several SNPs in ADAR, including rs1127313 (G/A), a SNP in the 3' untranslated region. In summary, germline variation involving RNA editing genes may influence EOC susceptibility, warranting further investigation of inherited and acquired alterations affecting RNA editing.

Adenosine Deaminase Activity in Chronic Lymphocytic Leukemia and Healthy Subjects

BACKGROUND

B cell chronic lymphocytic leukemia is one of the most frequent hematologic malignancies in the world. Cellular surface CD markers and serum Beta-2-microglobulin may be used as a prognostic tool in CLL patients.

OBJECTIVES

In the present study we introduce serum adenosine deaminase as a diagnostic marker in CLL.

MATERIALS AND METHODS

Blood samples were collected from B-CLL and healthy subjects. White blood cell, red blood cell and platelet count and blood Erythrocyte sedimentation rate was recorded and serum Beta-2-microglobulin, Lactate dehydrogenase and total ADA enzyme activity were determined.

RESULTS

Serum ADA activity was significantly higher in patients group than that of controls. ADA had a significant and direct correlation with B2M, WBC, LDH and ESR. However, there was not any relation between ADA and the stages of disease. Diagnostic cut-off, sensitivity and specificity of the serum ADA test were 27.97 U/L, 91% and 94%, respectively.

CONCLUSIONS

A higher ADA activity in patients group and its correlation with CLL markers were seen in our study. High diagnostic value of serum ADA in our study suggests that it might be considered as a useful screening tool among the other markers in CLL.

Purinergic signalling and cancer

Receptors for extracellular nucleotides are widely expressed by mammalian cells. They mediate a large array of responses ranging from growth stimulation to apoptosis, from chemotaxis to cell differentiation and from nociception to cytokine release, as well as neurotransmission. Pharma industry is involved in the development and clinical testing of drugs selectively targeting the different P1 nucleoside and P2 nucleotide receptor subtypes. As described in detail in the present review, P2 receptors are expressed by all tumours, in some cases to a very high level. Activation or inhibition of selected P2 receptor subtypes brings about cancer cell death or growth inhibition. The field has been largely neglected by current research in oncology, yet the evidence presented in this review, most of which is based on in vitro studies, although with a limited amount from in vivo experiments and human studies, warrants further efforts to explore the therapeutic potential of purinoceptor targeting in cancer.

Purine metabolites in fibromyalgia syndrome

OBJECTIVE

To evaluate serum purine metabolite concentrations in patients affected by fibromyalgia syndrome (FMS) and the relationships between their levels and FM clinical parameters.

DESIGN AND METHODS

Serum purine levels were quantified using LC/UV-vis in 22 fibromyalgic females (according to the American College of Rheumatology classification criteria) and 22 healthy females.

RESULTS

Significantly higher serum inosine, hypoxanthine and xanthine levels (p<0.001) and significantly lower serum adenosine (p<0.05) were detected in the FMS patients vs healthy controls. Our data show a negative correlation between adenosine and Fibromyalgia Impact Questionnaire (FIQ).

CONCLUSIONS

Study results suggest that purines, in particular adenosine and inosine, may be involved in pain transmission in fibromyalgia.