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1.
The Circular Life of Human CD38: From Basic Science to Clinics and Back.
Horenstein, AL, Faini, AC, Morandi, F, Bracci, C, Lanza, F, Giuliani, N, Paulus, A, Malavasi, F
Molecules (Basel, Switzerland). 2020;(20)
Abstract
Monoclonal antibodies (mAbs) were initially considered as a possible "magic bullet" for in vivo elimination of tumor cells. mAbs represented the first step: however, as they were murine in nature (the earliest experience on the field), they were considered unfit for human applications. This prompted the development of techniques for cloning the variable regions of conventional murine antibodies, genetically mounted on human IgG. The last step in this years-long process was the design for the preparation of fully human reagents. The choice of the target molecule was also problematic, since cancer-specific targets are quite limited in number. To overcome this obstacle in the planning phases of antibody-mediated therapy, attention was focused on a set of normal molecules, whose quantitative distribution may balance a tissue-dependent generalized expression. The results and clinical success obtained with anti-CD20 mAbs revived interest in this type of strategy. Using multiple myeloma (MM) as a tumor model was challenging first of all because the plasma cells and their neoplastic counterpart eluded the efforts of the Workshop on Differentiation Antigens to find a target molecule exclusively expressed by these cells. For this reason, attention was turned to surface molecules which fulfill the requisites of being reasonably good targets, even if not specifically restricted to tumor cells. In 2009, we proposed CD38 as a MM target in virtue of its expression: it is absent on early hematological progenitors, has variable but generalized limited expression by normal cells, but is extremely high in plasma cells and in myeloma. Further, regulation of its expression appeared to be dependent on a variety of factors, including exposure to all-trans retinoic acid (ATRA), a potent and highly specific inducer of CD38 expression in human promyelocytic leukemia cells that are now approved for in vivo use. This review discusses the history of human CD38, from its initial characterization to its targeting in antibody-mediated therapy of human myeloma.
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2.
Bridging the Imaging Gap: PSMA PET/CT Has a High Impact on Treatment Planning in Prostate Cancer Patients with Biochemical Recurrence-A Narrative Review of the Literature.
Ekmekcioglu, Ö, Busstra, M, Klass, ND, Verzijlbergen, F
Journal of nuclear medicine : official publication, Society of Nuclear Medicine. 2019;(10):1394-1398
Abstract
68Ga- and 18F-labeled prostate-specific membrane antigen (PSMA) molecules have created new opportunities for the unmet diagnostic needs in prostate cancer. The purpose of this article is to give an overview of studies that have examined the role of PSMA PET in treatment planning for prostate cancer patients with biochemical recurrence (BCR). Methods: Medline, Embase, Web of Science, Google Scholar, and Cochrane Central were searched for relevant articles. After excluding the articles that did not fulfill the required criteria, we included in this review 12 publications that reported the impact of PSMA PET on the treatment plan for prostate cancer patients with BCR. Results: All studies in our review emphasized the impact of PSMA PET images on therapy management in prostate cancer patients with BCR. Overall, the impact of PSMA PET/CT on therapy management varied between 30% and 76% among the 1,346 patients included in the review. Upstaging was reported in 32%-67% of the patients. Patients with low prostate-specific antigen values (<0.5 ng/mL) also demonstrated positive lesions, which could not have been detected by means of conventional imaging techniques. Important modifications to the original treatment plan included avoidance of systemic therapy (17%-40%) and PET-directed local therapy (in ≤60% of the patients). Conclusion: PSMA imaging demonstrated a high clinical impact in patients with BCR, with modifications to the original treatment plan occurring among half the patients. Detecting recurrence in BCR can prevent unnecessary toxicity and lead to individualized therapy.
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3.
Diagnostic tests for Niemann-Pick disease type C (NP-C): A critical review.
Vanier, MT, Gissen, P, Bauer, P, Coll, MJ, Burlina, A, Hendriksz, CJ, Latour, P, Goizet, C, Welford, RW, Marquardt, T, et al
Molecular genetics and metabolism. 2016;(4):244-54
Abstract
Niemann-Pick disease type C (NP-C) is a neurovisceral lysosomal cholesterol trafficking and lipid storage disorder caused by mutations in one of the two genes, NPC1 or NPC2. Diagnosis has often been a difficult task, due to the wide range in age of onset of NP-C and clinical presentation of the disease, combined with the complexity of the cell biology (filipin) laboratory testing, even in combination with genetic testing. This has led to substantial delays in diagnosis, largely depending on the access to specialist centres and the level of knowledge about NP-C of the physician in the area. In recent years, advances in mass spectrometry has allowed identification of several sensitive plasma biomarkers elevated in NP-C (e.g. cholestane-3β,5α,6β-triol, lysosphingomyelin isoforms and bile acid metabolites), which, together with the concomitant progress in molecular genetic technology, have greatly impacted the strategy of laboratory testing. Specificity of the biomarkers is currently under investigation and other pathologies are being found to also result in elevations. Molecular genetic testing also has its limitations, notably with unidentified mutations and the classification of new variants. This review is intended to increase awareness on the currently available approaches to laboratory diagnosis of NP-C, to provide an up to date, comprehensive and critical evaluation of the various techniques (cell biology, biochemical biomarkers and molecular genetics), and to briefly discuss ongoing/future developments. The use of current tests in proper combination enables a rapid and correct diagnosis in a large majority of cases. However, even with recent progress, definitive diagnosis remains challenging in some patients, for whom combined genetic/biochemical/cytochemical markers do not provide a clear answer. Expertise and reference laboratories thus remain essential, and further work is still required to fulfill unmet needs.
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4.
Candidate genes for COPD: current evidence and research.
Kim, WJ, Lee, SD
International journal of chronic obstructive pulmonary disease. 2015;:2249-55
Abstract
COPD is a common complex disease characterized by progressive airflow limitation. Several genome-wide association studies (GWASs) have discovered genes that are associated with COPD. Recently, candidate genes for COPD identified by GWASs include CHRNA3/5 (cholinergic nicotine receptor alpha 3/5), IREB2 (iron regulatory binding protein 2), HHIP (hedgehog-interacting protein), FAM13A (family with sequence similarity 13, member A), and AGER (advanced glycosylation end product-specific receptor). Their association with COPD susceptibility has been replicated in multiple populations. Since these candidate genes have not been considered in COPD, their pathological roles are still largely unknown. Herein, we review some evidences that they can be effective drug targets or serve as biomarkers for diagnosis or subtyping. However, more study is required to understand the functional roles of these candidate genes. Future research is needed to characterize the effect of genetic variants, validate gene function in humans and model systems, and elucidate the genes' transcriptional and posttranscriptional regulatory mechanisms.
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5.
The cardiorenal problem.
Pollock, E, Nowak, A
Swiss medical weekly. 2014;:w14051
Abstract
Cardiorenal syndrome (CRS) describes the reciprocally detrimental interaction between both acute and chronic cardiac and renal dysfunction. The syndrome is prevalent and carries a high mortality. CRS has five clinical subtypes, which share common pathogenetic mechanisms including neurohumoral and haemodynamic derangements. We describe several serum markers that offer improvements over traditional measurement of serum creatinine for the diagnosis of CRS. The mainstay of therapy of CRS is loop diuretics in the acute setting and ACE-inhibition in the chronic setting, the latter should in most cases continue despite therapy-associated increases in creatinine. Extracorporeal therapies remain second line treatment.
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6.
[Renal catabolism of albumin - current views and controversies].
Gburek, J, Gołąb, K, Juszczyńska, K
Postepy higieny i medycyny doswiadczalnej (Online). 2011;:668-77
Abstract
Albumin is the main protein of blood plasma, lymph, cerebrospinal fluid and interstitial fluid. The protein assists in many important body functions, including maintenance of proper colloidal osmotic pressure, transport of important metabolites and antioxidant action. Synthesis of albumin takes place mainly in the liver, and its catabolism occurs mostly in vascular endothelium of muscle, skin and liver as well as in the kidney tubular epithelium. Renal catabolism of albumin consists of glomerular filtration and tubular reabsorption. The tubular processes include endocytosis via the multiligand scavenger receptor tandem megalin and cubilin-amnionless complex. Possible ways of further catabolism of this protein are lysosomal proteolysis to amino acids and short peptides, recycling of degradation products into the bloodstream and tubular lumen or transcytosis of whole molecules. The article discusses the molecular aspects of these processes and presents the controversies arising in the light of the last decade of research.
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7.
GPVI and CLEC-2 in hemostasis and vascular integrity.
Watson, SP, Herbert, JM, Pollitt, AY
Journal of thrombosis and haemostasis : JTH. 2010;(7):1456-67
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Abstract
The glycoprotein VI (GPVI)-FcR gamma-chain complex initiates powerful activation of platelets by the subendothelial matrix proteins collagen and laminin through an immunoreceptor tyrosine-based activation motif (ITAM)-regulated signaling pathway. ITAMs are characterized by two YxxL sequences separated by 6-12 amino acids and are found associated with several classes of immunoglobulin (Ig) and C-type lectin receptors in hematopoietic cells, including Fc receptors. Cross-linking of the Ig GPVI leads to phosphorylation of two conserved tyrosines in the FcR gamma-chain ITAM by Src family tyrosine kinases, followed by binding and activation of the tandem SH2 domain-containing Syk tyrosine kinase and stimulation of a downstream signaling cascade that culminates in activation of phospholipase Cgamma2 (PLCgamma2). In contrast, the C-type lectin receptor CLEC-2 mediates powerful platelet activation through Src and Syk kinases, but regulates Syk through a novel dimerization mechanism via a single YxxL motif known as a hemITAM. CLEC-2 is a receptor for podoplanin, which is expressed at high levels in several tissues, including type 1 lung alveolar cells, lymphatic endothelial cells, kidney podocytes and some tumors, but is absent from vascular endothelial cells and platelets. In this article, we compare the mechanism of platelet activation by GPVI and CLEC-2 and consider their functional roles in hemostasis and other vascular processes, including maintenance of vascular integrity, angiogenesis and lymphogenesis.
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8.
[Biosynthetic pathway of GPI-anchored cell wall mannoproteins in yeast as a potential target for anti-fungal and anti-cancer drugs].
Jigami, Y
Nihon Ishinkin Gakkai zasshi = Japanese journal of medical mycology. 2008;(4):253-62
Abstract
Glycosylphosphatidyl-inositol (GPI) -anchored mannoproteins are one of the major cell wall components of eukaryotic microorganisms, including yeast and fungi. Some GPI-anchored proteins are localized at the plasma membrane, but others are processed at the plasma membrane and are covalently linked to beta-1, 6-glucan of the cell wall through the GPI portion. The genes and enzymes responsible for their biosynthesis and cell wall assembly are potential targets of anti-fungal reagents. We identified GWT1 as a new anti-fungal drug candidate target and elucidated its function as being involved in the acylation of the inositol ring. We also found a new function of GPI7 , which is involved in transfer of ethanolamine phosphate to Man2 of GPI. Our results indicate that the localization of GPI-anchored endoglucanase Egt2p is displaced from the septal region to the cell cortex at the restrictive temperature in gpi7 mutant cells, suggesting that GPI7 is involved in the separation of mother and daughter cells and its defective phenotype is a good marker to select a new inhibitor of Gpi7 function. We have also reported that PER1 is involved in lipid remodeling of GPI-anchored proteins, indicating that Per1p has a GPI-phospholipase A2 activity to eliminate the unsaturated fatty acyl chain at the sn-2 position of PI moiety. We further found that human PERLD1 , which is now known as an oncogene, is a functional homologue of yeast PER1 , indicating that this is a potential target for new anti-cancer drugs.
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9.
Structures of perfringolysin O suggest a pathway for activation of cholesterol-dependent cytolysins.
Rossjohn, J, Polekhina, G, Feil, SC, Morton, CJ, Tweten, RK, Parker, MW
Journal of molecular biology. 2007;(5):1227-36
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Abstract
Cholesterol-dependent cytolysins (CDCs), a large family of bacterial toxins, are secreted as water-soluble monomers and yet are capable of generating oligomeric pores in membranes. Previous work has demonstrated that large scale structural rearrangements occur during this transition but the detailed mechanism by which these changes take place remains a puzzle. Despite evidence of structural and functional couplings between domains 3 and 4, the crystal structure of the CDC, perfringolysin O (PFO), shows the two domains do not make direct contact. Here, we present crystal structures of PFO that demonstrate movements of domain 4 are sufficient to trigger conformational changes that are transmitted through the molecule to the distant domain 3. These coupled movements result in a loss of many contacts between domain 3 and rest of the molecule that would eventually lead to the exposure of transmembrane regions in preparation for membrane insertion. The structures reveal a detailed molecular pathway that may be the basis for the allosteric transition that occurs on initial membrane binding leading to the exposure of membrane-spanning regions in a domain distant from the initial site of interaction.
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10.
Soluble HLA class I molecules/CD8 ligation trigger apoptosis of CD8+ cells by Fas/Fas-ligand interaction.
Puppo, F, Contini, P, Ghio, M, Indiveri, F
TheScientificWorldJournal. 2002;:421-3
Abstract
The human major histocompatibility complex (HLA) encodes two sets of HLA class I molecules, which have been termed class Ia (or classical) and class Ib (or nonclassical) molecules. The class Ia molecules include the gene products of HLA-A, HLA-B, and HLA-C loci and are characterized by broad tissue expression and by a high degree of polymorphism. The class Ib molecules include the gene products of HLA-E, HLA-F, and HLA-G loci and are characterized by a restricted tissue distribution and by limited polymorphism. Besides being expressed on nucleated cells, classical and nonclassical HLA class I molecules are present in serum in soluble form (sHLA-I). The serum level of sHLA-I molecules is significantly increased in a variety of physiological and pathological conditions such as pregnancy, acute rejection episodes following organ allografts, acute graft-versus-host-disease (GVHD) following bone marrow transplantation, autoimmune diseases, viral infections, and malignant melanoma. Because of the statistically significant association with clinical parameters, the level of sHLA-I antigens has been suggested to represent a useful marker to predict the evolution of viral infections and to monitor the clinical course of allografts. Moreover, elevated levels of functional sHLA-I and soluble Fas-ligand molecules have been detected by our group in blood components and might play a role in the immunomodulatory effect of autologous and allogeneic transfusions. Several lines of evidence suggest that sHLA-I molecules are immunologically functional and may play an immunoregulatory role. In fact, they have been shown to elicit antibodies in both allogeneic and xenogeneic combinations, to inhibit the activity of alloreactive cytotoxic T lymphocytes (CTL), and to induce apoptosis in alloreactive and virus-specific CTL, in activated autologous and allogeneic CD8+ T cells, and in CD8+ NK cells. There is general agreement about the mechanism underlying the inhibition of CTL activity by sHLA antigens. This inhibition appears to be mediated by interactions of sHLA-I antigens a1 and a2 domains with T cell receptor (TCR). By contrast, there is conflicting information about the mechanism underlying induction of apoptosis of activated T cells by sHLA-I antigens. Several authors reported that sHLA-I molecules induced apoptosis of alloreactive CD8+ cytotoxic T lymphocytes through interaction with their TCR. However, our own data and those other groups indicate that classical and nonclassical sHLA-I molecules trigger Fas/Fas-ligand mediated apoptosis of phytohemoagglutinin (PHA)-activated and virus-specific CD8+ T lymphocytes as well as of CD8+ NK cells by interacting with CD8 coreceptor. Recently, we performed a series of experiments in our laboratory to clarify the intracellular mechanism(s) leading to Fas-ligand upregulation and secretion. These unpublished data indicate that sHLA-I/CD8 ligation elicits the phosphorylation of p56lck protein thyrosin kinase (PTK) associated with CD8 cytoplasmic domain in the absence of any other TCR-derived signal, the activation of syk-like ZAP-70 PTK and protein kinase C, and extracellular calcium influx. Then, activation and nuclear translocation of NF-kB and NF-AT occurs, leading to Fas-ligand mRNA transcription and soluble Fas-ligand secretion, which delivers the death signal. Interestingly, soluble Fas-ligand secretion and CD8+ cell apoptosis, but not CD8+ cell cytolitic activity, are completely inhibited by Cyclosporin A, which specifically blocks the activation of the calcineurin/calmodulin pathway. Taken together, these data suggest that sHLA-I molecules are involved in a signal-transduction pathway leading to Fas-ligand expression, soluble Fas-ligand secretion, and CD8+ cells apoptosis.