Impact of CTLA4 genotype and other immune response gene polymorphisms on outcomes after single umbilical cord blood transplantation.

We evaluated the impact of recipient and cord blood unit (CBU) genetic polymorphisms related to immune response on outcomes after unrelated cord blood transplantations (CBTs). Pretransplant DNA samples from 696 CBUs with malignant diseases were genotyped for NLRP1, NLRP2, NLRP3, TIRAP/Mal, IL10, REL, TNFRSF1B, and CTLA4. HLA compatibility was 6 of 6 in 10%, 5 of 6 in 39%, and ≥4 of 6 in 51% of transplants. Myeloablative conditioning was used in 80%, and in vivo T-cell depletion in 81%, of cases. The median number of total nucleated cells infused was 3.4 × 107/kg. In multivariable analysis, patients receiving CBUs with GG-CTLA4 genotype had poorer neutrophil recovery (hazard ratio [HR], 1.33; P = .02), increased nonrelapse mortality (NRM) (HR, 1.50; P < .01), and inferior disease-free survival (HR, 1.41; P = .02). We performed the same analysis in a more homogeneous subset of cohort 1 (cohort 2, n = 305) of patients who received transplants for acute leukemia, all given a myeloablative conditioning regimen, and with available allele HLA typing (HLA-A, -B, -C, and -DRB1). In this more homogeneous but smaller cohort, we were able to demonstrate that GG-CTLA4-CBU was associated with increased NRM (HR, 1.85; P = .01). Use of GG-CTLA4-CBU was associated with higher mortality after CBT, which may be a useful criterion for CBU selection, when multiple CBUs are available.

Potential roles of microRNA-29a in the molecular pathophysiology of T-cell acute lymphoblastic leukemia.

Recent evidence has shown that deregulated expression of members of the microRNA-29 (miR-29) family may play a critical role in human cancer, including hematological malignancies. However, the roles of miR-29 in the molecular pathophysiology of T-cell acute lymphoblastic leukemia (T-ALL) has not been investigated. Here, we show that lower levels of miR-29a were significantly associated with higher blast counts in the bone marrow and with increased disease-free survival in T-ALL patients. Furthermore, miR-29a levels are extremely reduced in T-ALL cells compared to normal T cells. Microarray analysis following introduction of synthetic miR-29a mimics into Jurkat cells revealed the downregulation of several predicted targets (CDK6, PXDN, MCL1, PIK3R1, and CXXC6), including targets with roles in active and passive DNA demethylation (such as DNMT3a, DNMT3b, and members of the TET family and TDG). Restoring miR-29a levels in Jurkat and Molt-4 T-ALL cells led to the demethylation of many genes commonly methylated in T-ALL. Overall, our results suggest that reduced miR-29a levels may contribute to the altered epigenetic status of T-ALL, highlighting its relevance in the physiopathology of this disease.

Genome-wide gene expression profiling reveals unsuspected molecular alterations in pemphigus foliaceus.

Pemphigus foliaceus (PF) is a complex autoimmune disease characterized by bullous skin lesions and the presence of antibodies against desmoglein 1. In this study we sought to contribute to a better understanding of the molecular processes in endemic PF, as the identification of factors that participate in the pathogenesis is a prerequisite for understanding its biological basis and may lead to novel therapeutic interventions. CD4+ T lymphocytes are central to the development of the disease. Therefore, we compared genome-wide gene expression profiles of peripheral CD4+ T cells of various PF patient subgroups with each other and with that of healthy individuals. The patient sample was subdivided into three groups: untreated patients with the generalized form of the disease, patients submitted to immunosuppressive treatment, and patients with the localized form of the disease. Comparisons between different subgroups resulted in 135, 54 and 64 genes differentially expressed. These genes are mainly related to lymphocyte adhesion and migration, apoptosis, cellular proliferation, cytotoxicity and antigen presentation. Several of these genes were differentially expressed when comparing lesional and uninvolved skin from the same patient. The chromosomal regions 19q13 and 12p13 concentrate differentially expressed genes and are candidate regions for PF susceptibility genes and disease markers. Our results reveal genes involved in disease severity, potential therapeutic targets and previously unsuspected processes involved in the pathogenesis. Besides, this study adds original information that will contribute to the understanding of PF's pathogenesis and of the still poorly defined in vivo functions of most of these genes.

NR3C1 polymorphisms in Brazilians of Caucasian, African, and Asian ancestry: glucocorticoid sensitivity and genotype association.

OBJECTIVE: The Brazilian population has heterogeneous ethnicity. No previous study evaluated NR3C1 polymorphisms in a Brazilian healthy population. MATERIALS AND METHODS: We assessed NR3C1 polymorphisms in Brazilians of Caucasian, African and Asian ancestry (n = 380). In a subgroup (n = 40), we compared the genotypes to glucocorticoid (GC) sensitivity, which was previously evaluated by plasma (PF) and salivary (SF) cortisol after dexamethasone (DEX) suppression tests, GC receptor binding affinity (K d ), and DEX-50% inhibition (IC 50 ) of concanavalin-A-stimulated mononuclear cell proliferation. p.N363S (rs6195), p.ER22/23EK (rs6189-6190), and BclI (rs41423247) allelic discrimination was performed by Real-Time PCR (Polymerase Chain Reaction). Exons 3 to 9 and exon/intron boundaries were amplified by PCR and sequenced. RESULTS: Genotypic frequencies (%) were: rs6195 (n = 380; AA:96.6/AG:3.14/GG:0.26), rs6189-6190 (n = 264; GG:99.6/GA:0.4), rs41423247 (n = 264; CC:57.9/CG:34.1/GG:8.0), rs6188 (n = 155; GG:69.6/GT:25.7/TT:4.7), rs258751 (n = 150; CC:88.0/CT:10.7/TT:1.3), rs6196 (n = 176; TT:77.2/TC:20.4/CC:2.4), rs67300719 (n = 137; CC:99.3/CT:0.7), and rs72542757 (n = 137; CC:99.3/CG:0.7). The rs67300719 and rs72542757 were found only in Asian descendants, in whom p.N363S and p.ER22/23EK were absent. The p.ER22/23EK was observed exclusively in Caucasian descendants. Hardy-Weinberg equilibrium was observed, except in the Asian for rs6188 and rs258751, and in the African for p.N363S. The K d , IC 50 , baseline and after DEX PF or SF did not differ between genotype groups. However, the mean DEX dose that suppressed PF or SF differed among the BclI genotypes (P = 0.03). DEX dose was higher in GG- (0.7 ± 0.2 mg) compared to GC- (0.47 ± 0.2 mg) and CC-carriers (0.47 ± 0.1 mg). CONCLUSION: The genotypic frequencies of NR3C1 polymorphisms in Brazilians are similar to worldwide populations. Additionally, the BclI polymorphism was associated with altered pituitary-adrenal axis GC sensitivity.

Hydroxycarbamide modulates components involved in the regulation of adenosine levels in blood cells from sickle-cell anemia patients.

Recent studies have demonstrated the role of adenosine (ADO) in sickle-cell anemia (SCA). ADO is produced by CD39 and CD73 and converted to inosine by adenosine deaminase (ADA). We evaluated the effects of hydroxycarbamide (HU) treatment on the modulation of adenosine levels in SCA patients. The expressions of CD39, CD73, and CD26 were evaluated by flow cytometry on blood cells in 15 HU-treated and 17 untreated patients and 10 healthy individuals. RNA was extracted from monocytes, and ADA gene expression was quantified by real-time PCR. ADA activity was also evaluated. We found that ADA transcripts were two times higher in monocytes of HU-treated patients, compared with untreated (P = 0.039). Monocytes of HU-treated patients expressed CD26, while monocytes of controls and untreated patients did not (P = 0.023). In treated patients, a lower percentage of T lymphocytes expressed CD39 compared with untreated (P = 0.003), and the percentage of T regulatory (Treg) cells was reduced in the treated group compared with untreated (P = 0.017) and controls (P = 0.0009). Besides, HU-treated patients displayed increased ADA activity, compared with untreated. Our results indicate a novel mechanism of action of HU mediated by the reduction of adenosine levels and its effects on pathophysiological processes in SCA.

NR3C1 polymorphisms in Brazilians of Caucasian, African, and Asian ancestry: glucocorticoid sensitivity and genotype association / Polimorfismos NR3C1 em brasileiros de ascendência caucasiana, africana e asiática: sensibilidade aos glicocorticoides e associação de genótipos

Objective : The Brazilian population has heterogeneous ethnicity. No previous study evaluated NR3C1 polymorphisms in a Brazilian healthy population. Materials and methods : We assessed NR3C1 polymorphisms in Brazilians of Caucasian, African and Asian ancestry (n = 380). In a subgroup (n = 40), we compared the genotypes to glucocorticoid (GC) sensitivity, which was previously evaluated by plasma (PF) and salivary (SF) cortisol after dexamethasone (DEX) suppression tests, GC receptor binding affinity (K d ), and DEX-50% inhibition (IC 50 ) of concanavalin-A-stimulated mononuclear cell proliferation. p.N363S (rs6195), p.ER22/23EK (rs6189-6190), and BclI (rs41423247) allelic discrimination was performed by Real-Time PCR (Polymerase Chain Reaction). Exons 3 to 9 and exon/intron boundaries were amplified by PCR and sequenced. Results : Genotypic frequencies (%) were: rs6195 (n = 380; AA:96.6/AG:3.14/GG:0.26), rs6189-6190 (n = 264; GG:99.6/GA:0.4), rs41423247 (n = 264; CC:57.9/CG:34.1/GG:8.0), rs6188 (n = 155; GG:69.6/GT:25.7/TT:4.7), rs258751 (n = 150; CC:88.0/CT:10.7/TT:1.3), rs6196 (n = 176; TT:77.2/TC:20.4/CC:2.4), rs67300719 (n = 137; CC:99.3/CT:0.7), and rs72542757 (n = 137; CC:99.3/CG:0.7). The rs67300719 and rs72542757 were found only in Asian descendants, in whom p.N363S and p.ER22/23EK were absent. The p.ER22/23EK was observed exclusively in Caucasian descendants. Hardy-Weinberg equilibrium was observed, except in the Asian for rs6188 and rs258751, and in the African for p.N363S. The K d , IC 50 , baseline and after DEX PF or SF did not differ between genotype groups. However, the mean DEX dose that suppressed PF or SF differed among the BclI genotypes (P = 0.03). DEX dose was higher in GG- (0.7 ± 0.2 mg) compared to GC- (0.47 ± 0.2 mg) and CC-carriers (0.47 ± 0.1 mg). Conclusion : The genotypic frequencies of NR3C1 polymorphisms in Brazilians are similar to worldwide populations. Additionally, the BclI polymorphism ...

Objetivo : Este estudo avalia polimorfismos (SNPs) do NR3C1 na população brasileira, que possui origem étnica heterogênea. Materiais e métodos : SNPs do NR3C1 foram avaliados em brasileiros de ancestralidade caucasiana, africana ou japonesa (n = 380). Em um subgrupo (n = 40), os genótipos foram comparados à sensibilidade aos glicocorticoides (GC), previamente avaliada por cortisol plasmático (PF) e salivar (SF) após supressão com dexametasona (DEX), ensaio de afinidade do receptor ao GC (K d ) e inibição por DEX de 50% da proliferação de mononucleares estimulada por concanavalina-A (IC 50 ). Discriminação alélica de p.N363S (rs6195), p.ER22/23EK (rs6189-6190) e BclI (rs41423247) foi realizada por PCR em tempo real. Éxons 3 a 9 e transições éxon/íntron foram amplificados e sequenciados. Resultados : Frequências genotípicas (%) foram: rs6195 (n = 380; AA:96,6/AG:3,14/GG:0,26), rs6189-6190 (n = 264; GG:99,6/GA:0,4), rs41423247 (n = 264; CC:57,9/CG:34,1/GG:8,0), rs6188 (n = 155; GG:69,6/GT:25,7/TT:4,7), rs258751 (n = 150; CC:88,0/CT:10,7/TT:1,3), rs6196 (n = 176; TT:77,2/TC:20,4/CC:2,4), rs67300719 (n = 137; CC:99,3/CT:0,7), e rs72542757 (n = 137; CC:99,3/CG:0,7). Enquanto rs67300719 e rs72542757 foram exclusivos dos nipodescendentes, p.N363S e p.ER22/23EK estavam ausentes nesses indivíduos. p.ER22/23EK foi exclusivo dos descendentes de caucasianos. Equilíbrio de Hardy-Weinberg foi observado, exceto nos nipodescendentes para rs6188 e rs258751 e nos afrodescendentes para p.N363S. K d , IC 50 , PF ou SF basal ou após DEX foram semelhantes entre os genótipos. Entretanto, a dose média de DEX que suprimiu PF ou SF diferiu entre os genótipos BclI (P = 0,03), sendo maior nos carreadores GG (0,7 ± 0,2 mg) comparada aos GC (0,47 ± 0,2 mg) e CC (0,47 ± 0,1 mg). Conclusão : As ...

Expression of calcium binding protein S100 A7 (psoriasin) in laryngeal carcinoma.

UNLABELLED: Many studies have reported increased expression of S100 A7 (psoriasin) in neoplastic lesions. Among them are studies on breast carcinoma, bladder squamous cell carcinoma, skin tumors and oral cavity squamous cell carcinoma. The expression of S100 A7 has not been described for laryngeal cancer. OBJECTIVE: This study aims to identify the expression of the calcium-binding protein S100 A7 and its correlation with squamous cell carcinomas of the larynx. MATERIAL AND METHODS: Specimens from 63 patients were submitted to immunohistochemistry testing with antibody S100 A7. Results were classified and compared. RESULTS: The group with highly differentiated tumors had the highest treatment failure scores. Moderately differentiated tumors had higher treatment failure scores than poorly differentiated tumors. Higher scores were predominantly seen on stages I and II in moderately differentiated tumors, whereas score distribution was more homogeneous in advanced stage disease (III and IV). Regarding failure in treatment, the group scoring zero (3/4 complications: 75%) differed significantly from the remaining groups (13/59: 22%). CONCLUSIONS: S100 A7 marker was expressed in 93.7% of laryngeal cancer cases, with higher positive correlation rates in more differentiated tumors and significantly lower rates of treatment failure. Scores had no impact on survival rates.

Expressão da proteína ligadora de cálcio S100 A7 (psoriasina) no carcinoma laríngeo / Expression of calcium binding protein S100 A7 (psoriasin) in laryngeal carcinoma

Muitos estudos relatam o aumento da expressão de S100 A7 (psoriasina) em lesões neoplásicas. Destacam-se trabalhos em carcinoma da mama, espinocelular da bexiga, pele e cavidade oral. Não foi demonstrada expressão da S100 A7 em câncer de laringe. OBJETIVO: Identificar a expressão da proteína ligadora de cálcio S100 A7 e sua correlação com carcinomas espinocelular da laringe. MATERIAL E MÉTODOS: Amostras de tecido neoplásico de 63 pacientes foram submetidos à imunohis toquímica com o anticorpo S110 A7. Os resultados foram classificados e comparados. RESULTADOS: O grupo bem diferenciado teve a maior pontuação de falha no tratamento. O grupo moderadamente diferenciado apresentou escores mais elevados do que o grupo pouco diferenciado. Pontuações mais altas predominaram nos estágios I e II no grupo moderadamente diferenciado, enquanto a distribuição do escore foi mais homogênea em estados avançados (III e IV). Em relação às falhas no tratamento, o grupo pontuação zero (04/03 complicações: 75%) diferiu significativamente da pontuação restante (13/59: 22%). CONCLUSÕES: A S100 A7 foi expressa em 93,7% dos casos de câncer de laringe, com maior positividade nos tumores mais diferenciados e taxa significativamente menor de falha no tratamento. A pontuação obtida não teve impacto sobre a sobrevivência.

Many studies have reported increased expression of S100 A7 (psoriasin) in neoplastic lesions. Among them are studies on breast carcinoma, bladder squamous cell carcinoma, skin tumors and oral cavity squamous cell carcinoma. The expression of S100 A7 has not been described for laryngeal cancer. OBJECTIVE: This study aims to identify the expression of the calcium-binding protein S100 A7 and its correlation with squamous cell carcinomas of the larynx. MATERIAL AND METHODS: Specimens from 63 patients were submitted to immunohistochemistry testing with antibody S100 A7. Results were classified and compared. RESULTS: The group with highly differentiated tumors had the highest treatment failure scores. Moderately differentiated tumors had higher treatment failure scores than poorly differentiated tumors. Higher scores were predominantly seen on stages I and II in moderately differentiated tumors, whereas score distribution was more homogeneous in advanced stage disease (III and IV). Regarding failure in treatment, the group scoring zero (3/4 complications: 75%) differed significantly from the remaining groups (13/59: 22%). CONCLUSIONS: S100 A7 marker was expressed in 93.7% of laryngeal cancer cases, with higher positive correlation rates in more differentiated tumors and significantly lower rates of treatment failure. Scores had no impact on survival rates.

The Aurora A and B kinases are up-regulated in bone marrow-derived chronic lymphocytic leukemia cells and represent potential therapeutic targets.

BACKGROUND: The malignant B cells in chronic lymphocytic leukemia receive signals from the bone marrow and lymph node microenvironments which regulate their survival and proliferation. Characterization of these signals and the pathways that propagate them to the interior of the cell is important for the identification of novel potential targets for therapeutic intervention. DESIGN AND METHODS: We compared the gene expression profiles of chronic lymphocytic leukemia B cells purified from bone marrow and peripheral blood to identify genes that are induced by the bone marrow microenvironment. Two of the differentially expressed genes were further studied in cell culture experiments and in an animal model to determine whether they could represent appropriate therapeutic targets in chronic lymphocytic leukemia. RESULTS: Functional classification analysis revealed that the majority of differentially expressed genes belong to gene ontology categories related to cell cycle and mitosis. Significantly up-regulated genes in bone marrow-derived tumor cells included important cell cycle regulators, such as Aurora A and B, survivin and CDK6. Down-regulation of Aurora A and B by RNA interference inhibited proliferation of chronic lymphocytic leukemia-derived cell lines and induced low levels of apoptosis. A similar effect was observed with the Aurora kinase inhibitor VX-680 in primary chronic lymphocytic leukemia cells that were induced to proliferate by CpG-oligonucleotides and interleukin-2. Moreover, VX-680 significantly blocked leukemia growth in a mouse model of chronic lymphocytic leukemia. CONCLUSIONS: Aurora A and B are up-regulated in proliferating chronic lymphocytic leukemia cells and represent potential therapeutic targets in this disease.

Mesenchymal stem cells promote the sustained expression of CD69 on activated T lymphocytes: roles of canonical and non-canonical NF-κB signalling.

Mesenchymal stem cells (MSCs) are known to induce the conversion of activated T cells into regulatory T cells in vitro. The marker CD69 is a target of canonical nuclear factor kappa-B (NF-κB) signalling and is transiently expressed upon activation; however, stable CD69 expression defines cells with immunoregulatory properties. Given its enormous therapeutic potential, we explored the molecular mechanisms underlying the induction of regulatory cells by MSCs. Peripheral blood CD3(+) T cells were activated and cultured in the presence or absence of MSCs. CD4(+) cell mRNA expression was then characterized by microarray analysis. The drug BAY11-7082 (BAY) and a siRNA against v-rel reticuloendotheliosis viral oncogene homolog B (RELB) were used to explore the differential roles of canonical and non-canonical NF-κB signalling, respectively. Flow cytometry and real-time PCR were used for analyses. Genes with immunoregulatory functions, CD69 and non-canonical NF-κB subunits (RELB and NFKB2) were all expressed at higher levels in lymphocytes co-cultured with MSCs. The frequency of CD69(+) cells among lymphocytes cultured alone progressively decreased after activation. In contrast, the frequency of CD69(+) cells increased significantly following activation in lymphocytes co-cultured with MSCs. Inhibition of canonical NF-κB signalling by BAY immediately following activation blocked the induction of CD69; however, inhibition of canonical NF-κB signalling on the third day further induced the expression of CD69. Furthermore, late expression of CD69 was inhibited by RELB siRNA. These results indicate that the canonical NF-κB pathway controls the early expression of CD69 after activation; however, in an immunoregulatory context, late and sustained CD69 expression is promoted by the non-canonical pathway and is inhibited by canonical NF-κB signalling.

Expression of human protein S100A7 (psoriasin), preparation of antibody and application to human larynx squamous cell carcinoma.

BACKGROUND: Up-regulation of S100A7 (Psoriasin), a small calcium-binding protein, is associated with the development of several types of carcinomas, but its function and possibility to serve as a diagnostic or prognostic marker have not been fully defined. In order to prepare antibodies to the protein for immunohistochemical studies we produced the recombinant S100A7 protein in E. coli. mRNA extracted from human tracheal tumor tissue which was amplified by RT-PCR to provide the region coding for the S100A7 gene. The amplified fragment was cloned in the vector pCR2.1-TOPO and sub-cloned in the expression vector pAE. The protein rS100A7 (His-tag) was expressed in E. coli BL21::DE3, purified by affinity chromatography on an Ni-NTA column, recovered in the 2.0 to 3.5 mg/mL range in culture medium, and used to produce a rabbit polyclonal antibody anti-rS100A7 protein. The profile of this polyclonal antibody was evaluated in a tissue microarray. RESULTS: The rS100A7 (His-tag) protein was homogeneous by SDS-PAGE and mass spectrometry and was used to produce an anti-recombinant S100A7 (His-tag) rabbit serum (polyclonal antibody anti-rS100A7). The molecular weight of rS100A7 (His-tag) protein determined by linear MALDI-TOF-MS was 12,655.91 Da. The theoretical mass calculated for the nonapeptide attached to the amino terminus is 12,653.26 Da (delta 2.65 Da). Immunostaining with the polyclonal anti-rS100A7 protein generated showed reactivity with little or no background staining in head and neck squamous cell carcinoma cells, detecting S100A7 both in nucleus and cytoplasm. Lower levels of S100A7 were detected in non-neoplastic tissue. CONCLUSIONS: The polyclonal anti-rS100A7 antibody generated here yielded a good signal-to-noise contrast and should be useful for immunohistochemical detection of S100A7 protein. Its potential use for other epithelial lesions besides human larynx squamous cell carcinoma and non-neoplastic larynx should be explored in future.

Halofuginone has anti-proliferative effects in acute promyelocytic leukemia by modulating the transforming growth factor beta signaling pathway.

Promyelocytic leukemia-retinoic acid receptor alpha (PML-RARα) expression in acute promyelocytic leukemia (APL) impairs transforming growth factor beta (TGFß) signaling, leading to cell growth advantage. Halofuginone (HF), a low-molecular-weight alkaloid that modulates TGFß signaling, was used to treat APL cell lines and non-obese diabetic/severe combined immunodeficiency (NOD/SCID) mice subjected to transplantation with leukemic cells from human chorionic gonadotrophin-PML-RARα transgenic mice (TG). Cell cycle analysis using incorporated bromodeoxyuridine and 7-amino-actinomycin D showed that, in NB4 and NB4-R2 APL cell lines, HF inhibited cellular proliferation (P<0.001) and induced apoptosis (P = 0.002) after a 24-hour incubation. Addition of TGFß revealed that NB4 cells were resistant to its growth-suppressive effects and that HF induced these effects in the presence or absence of the cytokine. Cell growth inhibition was associated with up-regulation of TGFß target genes involved in cell cycle regulation (TGFB, TGFBRI, SMAD3, p15, and p21) and down-regulation of MYC. Additionally, TGFß protein levels were decreased in leukemic TG animals and HF in vivo could restore TGFß values to normal. To test the in vivo anti-leukemic activity of HF, we transplanted NOD/SCID mice with TG leukemic cells and treated them with HF for 21 days. HF induced partial hematological remission in the peripheral blood, bone marrow, and spleen. Together, these results suggest that HF has anti-proliferative and anti-leukemic effects by reversing the TGFß blockade in APL. Since loss of the TGFß response in leukemic cells may be an important second oncogenic hit, modulation of TGFß signaling may be of therapeutic interest.

Mesenchymal stromal cells up-regulate CD39 and increase adenosine production to suppress activated T-lymphocytes.

Mesenchymal stromal cells (MSCs) suppress T cell responses through mechanisms not completely understood. Adenosine is a strong immunosuppressant that acts mainly through its receptor A(2a) (ADORA2A). Extracellular adenosine levels are a net result of its production (mediated by CD39 and CD73), and of its conversion into inosine by Adenosine Deaminase (ADA). Here we investigated the involvement of ADO in the immunomodulation promoted by MSCs. Human T lymphocytes were activated and cultured with or without MSCs. Compared to lymphocytes cultured without MSCs, co-cultured lymphocytes were suppressed and expressed higher levels of ADORA2A and lower levels of ADA. In co-cultures, the percentage of MSCs expressing CD39, and of T lymphocytes expressing CD73, increased significantly and adenosine levels were higher. Incubation of MSCs with media conditioned by activated T lymphocytes induced the production of adenosine to levels similar to those observed in co-cultures, indicating that adenosine production was mainly derived from MSCs. Finally, blocking ADORA2A signaling raised lymphocyte proliferation significantly. Our results suggest that some of the immunomodulatory properties of MSCs may, in part, be mediated through the modulation of components related to adenosine signaling. These findings may open new avenues for the development of new treatments for GVHD and other inflammatory diseases.

Constitutional telomerase mutations are genetic risk factors for cirrhosis.

UNLABELLED: Some patients with liver disease progress to cirrhosis, but the risk factors for cirrhosis development are unknown. Dyskeratosis congenita, an inherited bone marrow failure syndrome associated with mucocutaneous anomalies, pulmonary fibrosis, and cirrhosis, is caused by germline mutations of genes in the telomerase complex. We examined whether telomerase mutations also occurred in sporadic cirrhosis. In all, 134 patients with cirrhosis of common etiologies treated at the Liver Research Institute, University of Arizona, between May 2008 and July 2009, and 528 healthy subjects were screened for variation in the TERT and TERC genes by direct sequencing; an additional 1,472 controls were examined for the most common genetic variation observed in patients. Telomere length of leukocytes was measured by quantitative polymerase chain reaction. Functional effects of genetic changes were assessed by transfection of mutation-containing vectors into telomerase-deficient cell lines, and telomerase activity was measured in cell lysates. Nine of the 134 patients with cirrhosis (7%) carried a missense variant in TERT, resulting in a cumulative carrier frequency significantly higher than in controls (P = 0.0009). One patient was homozygous and eight were heterozygous. The allele frequency for the most common missense TERT variant was significantly higher in patients with cirrhosis (2.6%) than in 2,000 controls (0.7%; P = 0.0011). One additional patient carried a TERC mutation. The mean telomere length of leukocytes in patients with cirrhosis, including six mutant cases, was shorter than in age-matched controls (P = 0.0004). CONCLUSION: Most TERT gene variants reduced telomerase enzymatic activity in vitro. Loss-of-function telomerase gene variants associated with short telomeres are risk factors for sporadic cirrhosis.

Genetic variation among major human geographic groups supports a peculiar evolutionary trend in PAX9.

A total of 172 persons from nine South Amerindian, three African and one Eskimo populations were studied in relation to the Paired box gene 9 (PAX9) exon 3 (138 base pairs) as well as its 5'and 3'flanking intronic segments (232 bp and 220 bp, respectively) and integrated with the information available for the same genetic region from individuals of different geographical origins. Nine mutations were scored in exon 3 and six in its flanking regions; four of them are new South American tribe-specific singletons. Exon3 nucleotide diversity is several orders of magnitude higher than its intronic regions. Additionally, a set of variants in the PAX9 and 101 other genes related with dentition can define at least some dental morphological differences between Sub-Saharan Africans and non-Africans, probably associated with adaptations after the modern human exodus from Africa. Exon 3 of PAX9 could be a good molecular example of how evolvability works.

Assessing individual interethnic admixture and population substructure using a 48-insertion-deletion (INSEL) ancestry-informative marker (AIM) panel.

Estimating the proportions of different ancestries in admixed populations is very important in population genetics studies, and it is particularly important for detecting population substructure effects in case-control association studies. In this work, a set of 48 ancestry-informative insertion-deletion polymorphisms (INDELs) were selected with the goal of efficiently measuring the proportions of three different ancestries (sub-Saharan African, European, and Native American) in mixed populations. All selected markers can be easily analyzed via multiplex PCR and detected with standard capillary electrophoresis. A total of 593 unrelated individuals representative of European, African, and Native American parental populations were typed, as were 380 individuals from three Brazilian populations with known admixture patterns. As expected, the interethnic admixture estimates show that individuals from southern Brazil present an almost exclusively European ancestry; Afro-descendant communities in the Amazon region, apart from the major African contribution, present some degree of admixture with Europeans and Native Americans; and a sample from Belém, in the northeastern Amazon, shows a significant contribution of the three ethnic groups, although with a greater European proportion. In summary, a panel of ancestry-informative INDELs was optimized and proven to be a valuable tool for estimating individual and global ancestry proportions in admixed populations. The ability to accurately infer interethnic admixtures highlights the usefulness of this marker set for assessing population substructure in association studies, particularly those conducted in Brazilian and other Latin American populations sharing trihybrid ancestry patterns.

A score system for quality evaluation of RNA sequence tags: an improvement for gene expression profiling.

BACKGROUND: High-throughput molecular approaches for gene expression profiling, such as Serial Analysis of Gene Expression (SAGE), Massively Parallel Signature Sequencing (MPSS) or Sequencing-by-Synthesis (SBS) represent powerful techniques that provide global transcription profiles of different cell types through sequencing of short fragments of transcripts, denominated sequence tags. These techniques have improved our understanding about the relationships between these expression profiles and cellular phenotypes. Despite this, more reliable datasets are still necessary. In this work, we present a web-based tool named S3T: Score System for Sequence Tags, to index sequenced tags in accordance with their reliability. This is made through a series of evaluations based on a defined rule set. S3T allows the identification/selection of tags, considered more reliable for further gene expression analysis. RESULTS: This methodology was applied to a public SAGE dataset. In order to compare data before and after filtering, a hierarchical clustering analysis was performed in samples from the same type of tissue, in distinct biological conditions, using these two datasets. Our results provide evidences suggesting that it is possible to find more congruous clusters after using S3T scoring system. CONCLUSION: These results substantiate the proposed application to generate more reliable data. This is a significant contribution for determination of global gene expression profiles. The library analysis with S3T is freely available at http://gdm.fmrp.usp.br/s3t/. S3T source code and datasets can also be downloaded from the aforementioned website.

Constitutional hypomorphic telomerase mutations in patients with acute myeloid leukemia.

Loss-of-function mutations in telomerase complex genes can cause bone marrow failure, dyskeratosis congenita, and acquired aplastic anemia, both diseases that predispose to acute myeloid leukemia. Loss of telomerase function produces short telomeres, potentially resulting in chromosome recombination, end-to-end fusion, and recognition as damaged DNA. We investigated whether mutations in telomerase genes also occur in acute myeloid leukemia. We screened bone marrow samples from 133 consecutive patients with acute myeloid leukemia and 198 controls for variations in TERT and TERC genes. An additional 89 patients from a second cohort, selected based on cytogenetic status, and 528 controls were further examined for mutations. A third cohort of 372 patients and 384 controls were specifically tested for one TERT gene variant. In the first cohort, 11 patients carried missense TERT gene variants that were not present in controls (P < 0.0001); in the second cohort, TERT mutations were associated with trisomy 8 and inversion 16. Mutation germ-line origin was demonstrated in 5 patients from whom other tissues were available. Analysis of all 3 cohorts (n = 594) for the most common gene variant (A1062T) indicated a prevalence 3 times higher in patients than in controls (n = 1,110; P = 0.0009). Introduction of TERT mutants into telomerase-deficient cells resulted in loss of enzymatic activity by haploinsufficiency. Inherited mutations in TERT that reduce telomerase activity are risk factors for acute myeloid leukemia. We propose that short and dysfunctional telomeres limit normal stem cell proliferation and predispose for leukemia by selection of stem cells with defective DNA damage responses that are prone to genome instability.

SAGE analysis demonstrates increased expression of TOSO contributing to Fas-mediated resistance in CLL.

To identify novel genes involved in the molecular pathogenesis of chronic lymphocytic leukemia (CLL) we performed a serial analysis of gene expression (SAGE) in CLL cells, and compared this with healthy B cells (nCD19(+)). We found a high level of similarity among CLL subtypes, but a comparison of CLL versus nCD19(+) libraries revealed 55 genes that were over-represented and 49 genes that were down-regulated in CLL. A gene ontology analysis revealed that TOSO, which plays a functional role upstream of Fas extrinsic apoptosis pathway, was over-expressed in CLL cells. This finding was confirmed by real-time reverse transcription-polymerase chain reaction in 78 CLL and 12 nCD19(+) cases (P < .001). We validated expression using flow cytometry and tissue microarray and demonstrated a 5.6-fold increase of TOSO protein in circulating CLL cells (P = .013) and lymph nodes (P = .006). Our SAGE results have demonstrated that TOSO is a novel over-expressed antiapoptotic gene in CLL.

Mitochondrial population genomics supports a single pre-Clovis origin with a coastal route for the peopling of the Americas.

It is well accepted that the Americas were the last continents reached by modern humans, most likely through Beringia. However, the precise time and mode of the colonization of the New World remain hotly disputed issues. Native American populations exhibit almost exclusively five mitochondrial DNA (mtDNA) haplogroups (A-D and X). Haplogroups A-D are also frequent in Asia, suggesting a northeastern Asian origin of these lineages. However, the differential pattern of distribution and frequency of haplogroup X led some to suggest that it may represent an independent migration to the Americas. Here we show, by using 86 complete mitochondrial genomes, that all Native American haplogroups, including haplogroup X, were part of a single founding population, thereby refuting multiple-migration models. A detailed demographic history of the mtDNA sequences estimated with a Bayesian coalescent method indicates a complex model for the peopling of the Americas, in which the initial differentiation from Asian populations ended with a moderate bottleneck in Beringia during the last glacial maximum (LGM), around approximately 23,000 to approximately 19,000 years ago. Toward the end of the LGM, a strong population expansion started approximately 18,000 and finished approximately 15,000 years ago. These results support a pre-Clovis occupation of the New World, suggesting a rapid settlement of the continent along a Pacific coastal route.