Cell Proliferation In Patients Research Articles

Abstract IA11: Chemoprevention in hereditary GI cancer syndromes

Abstract IA11: Chemoprevention in hereditary GI cancer syndromes

Myeloid Neoplasm Gene Somatic Mutations in Patients with Severe Aplastic Anemia Treated with Eltrombopag and Standard Immunosuppression

▪The major complication of severe aplastic anemia is clonal evolution, defined as any new cytogenetic abnormality or progression to MDS/AML, which occurs in about 15% of SAA patients, usually many months to years after the diagnosis. Eltrombopag, a thrombopoietin receptor agonist, appears capable of stimulating hematopoietic stem cell proliferation in patients with bone marrow failure. Addition of eltrombopag to standard immunosuppressive treatment (IST) with horse antithymocyte globulin (hATG) and cyclosporine (CsA) markedly increases hematologic response rates in treatment-naive SAA, with overall response rates up to 90% and complete response rates approaching 60% (Townsley DM et al, ASH 2015, clinicaltrials.gov NCT01623167). In comparison, IST alone achieves 60% overall response rates, of which 10% are complete (Scheinberg Blood 2012). Somatic mutations in myeloid cancer candidate genes are present in one-third of patients after IST alone (Yoshizato T et al, NEJM 2015). Specific subsets of mutations were associated with clinical outcomes: a group including ASXL1 and DNMT3A with a poor response to IST, inferior survival, and clonal evolution, while BCOR and PIGA were associated with good response and favorable outcomes. Monosomy 7, the most prevalent cytogenetic abnormality defining clonal evolution, can develop in the absence of gene mutations, underscoring the non-determinative and complex role mutations play in clonal evolution (Dumitriu B et al, Blood 2015). Of patients with disease refractory to IST who were subsequently treated with single-agent eltrombopag, 19% (8/43) developed cytogenetic abnormalities, usually within the first year of treatment, but only rarely with morphologic changes consistent with MDS/AML (Desmond R et al, Blood 2014). The frequency of somatic mutations following treatment with eltrombopag added to IST in treatment-naïve SAA patients is unknown.We used amplicon-based next-generation sequencing to assess mutations in 54 candidate genes recurrently mutated in myeloid neoplasms. Bone marrow cells of 90 subjects who had been treated with IST/eltrombopag were obtained at 6 months following treatment initiation, or at the time of clonal evolution. At least one detectable mutation was identified in 21 (23%) subjects. All 21 patients had exhibited a hematologic response to treatment by 6 months; of those patients with somatic mutations, 14 of 19 (74%) had a complete hematologic response. In comparison, of the 69 patients who lacked mutations, 20 (29%) had a complete response. Nine different genes were mutated in total, with the most frequent genes being ASXL1 and BCOR. BCOR was associated with more robust responses (6 of 7 had a complete response) and younger age (range 12 - 49 years; Table). One subject with a longstanding history of JAK2-positive essential thrombocytosis and myelofibrosis at baseline had two additional mutations detectable following treatment, TET2 and ASXL1.With a median follow up of 21 months, clonal cytogenetic evolution occurred in 7/90 (8%) subjects. Three of seven patients also had a mutation in a myeloid cancer gene (two with DNMT3A and one with ASXL1/RUNX1); in the other four, no somatic mutation was detected, either at the 6-month time point or at time of cytogenetic evolution. Four patients had monosomy or partial deletion of chromosome 7: one patient had complex (t(3;3)(q21;q26), -7), one patient had deletion 13q that later disappeared, and one patient had trisomy 6 and trisomy 15 in 2 metaphases. The patient with complex cytogenetics did not have somatic mutations detected at evolution, and she later died due to relapsed AML following transplant.The rates of somatic mutations in myeloid cancer genes and of cytogenetic evolution in patients treated with IST/eltrombopag do not appear to be higher than we and others have reported in aplastic anemia treated with standard IST, without eltrombopag (Kulasekararaj AG et al, Blood 2014). The distribution of genes mutated and the allelic frequency of these mutations also were similar to patients treated with standard IST. These results suggest that the benefits of a higher response rate and quality of response associated with the addition of eltrombopag to IST for the initial treatment of SAA are not associated with a higher risk of clonal progression. [Display omitted] DisclosuresTownsley:GSK/Novartis: Research Funding. Cooper:GSK/Novartis: Research Funding. Winkler:GSK/Novartis: Research Funding. Scheinberg:Novartis: Consultancy, Speakers Bureau. Rios:GSK/Novartis: Research Funding. Weinstein:GSK/Novartis: Research Funding. Desierto:GSK/Novartis: Research Funding. Fernandez Ibanez:GSK/Novartis: Research Funding. Dunbar:GSK/Novartis: Research Funding. Ma:Neogenomics Laboratories: Employment. Albitar:Neogenomics Laboratories: Employment, Equity Ownership. Young:GSK/Novartis: Research Funding.

TGFβ1 overexpression is associated with improved survival and low tumor cell proliferation in patients with early-stage pancreatic ductal adenocarcinoma.

The role of transforming growth factor beta-type-1 (TGFβ1) in pancreatic ductal adenocarcinoma (PDAC) progression is stage-dependent. We hypothesized that TGFβ1 expression is associated with survival and proliferation markers in patients with early-stage PDAC. We acquired clinicopathologic, treatment, and mRNA expression data from The Cancer Genome Atlas data set for 106 patients identified with stage I/II PDAC who underwent pancreaticoduodenectomy. Patients were categorized as high expression when mRNA expression was ≥75th percentile for each gene. Average log2 mRNA expression of TGFβ1 in patients with high expression was 11.6 ± 0.2 and 10.5 ± 0.6 in patients with low expression (P<0.001). Low TGFβ1 expression is associated with shorter median survival compared with high TGFβ1 expression (17 versus at least 60 months; P=0.005). Patients with tumors demonstrating high MKI67 (the gene encoding Ki-67) expression have shorter median survival versus those with lowerMKI67 expression (16 versus 20 months; P=0.026). TGFβ1 and MKI67 are inversely associated (P=0.009). On multivariate analysis, improved survival is associated with TGFβ1 overexpression (P=0.017), adjuvant chemotherapy (P=0.001), and adjuvant radiotherapy (P=0.017), whereas positive surgical margins are associated with worse survival (P=0.002). In patients who undergo pancreaticoduodenectomy for PDAC, high TGFβ1 expression may counteract the worse survival associated with high proliferation.

Early memory phenotypes drive T cell proliferation in patients with pediatric malignancies.

Engineered T cell therapies have begun to demonstrate impressive clinical responses in patients with B cell malignancies. Despite this efficacy, many patients are unable to receive T cell therapy because of failure of in vitro expansion, a necessary component of cell manufacture and a predictor of in vivo activity. To evaluate the biology underlying these functional differences, we investigated T cell expansion potential and memory phenotype during chemotherapy in pediatric patients with acute lymphoblastic leukemia (ALL) and non-Hodgkin lymphoma (NHL). We found that patients with T cell populations enriched for early lineage cells expanded better in vitro and that patients with ALL had higher numbers of these cells with a corresponding enhancement in expansion as compared to cells from patients with NHL. We further demonstrated that early lineage cells were selectively depleted by cyclophosphamide and cytarabine chemotherapy and that culture with interleukin-7 (IL-7) and IL-15 enriched select early lineage cells and rescued T cell expansion capability. Thus, early lineage cells are essential to T cell fitness for expansion, and enrichment of this population either by timing of T cell collection or culture method can increase the number of patients eligible to receive highly active engineered cellular therapies.

CD4+ FOXP3+ Regulatory T Cells Exhibit Impaired Ability to Suppress Effector T Cell Proliferation in Patients with Turner Syndrome.

ObjectiveWe investigated whether the frequency, phenotype, and suppressive function of CD4+FOXP3+ regulatory T cells (Tregs) are altered in young TS patients with the 45,X karyotype compared to age-matched controls.Design and MethodsPeripheral blood mononuclear cells from young TS patients (n = 24, 17.4–35.9 years) and healthy controls (n = 16) were stained with various Treg markers to characterize their phenotypes. Based on the presence of thyroid autoimmunity, patients were categorized into TS (–) (n = 7) and TS (+) (n = 17). Tregs sorted for CD4+CD25bright were co-cultured with autologous CD4+CD25− target cells in the presence of anti-CD3 and -CD28 antibodies to assess their suppressive function.ResultsDespite a lower frequency of CD4+ T cells in the TS (-) and TS (+) patients (mean 30.8% and 31.7%, vs. 41.2%; P = 0.003 and P < 0.001, respectively), both groups exhibited a higher frequency of FOXP3+ Tregs among CD4+ T cells compared with controls (means 1.99% and 2.05%, vs. 1.33%; P = 0.029 and P = 0.004, respectively). There were no differences in the expression of CTLA-4 and the frequency of Tregs expressing CXCR3+, and CCR4+CCR6+ among the three groups. However, the ability of Tregs to suppress the in vitro proliferation of autologous CD4+CD25− T cells was significantly impaired in the TS (–) and TS (+) patients compared to controls (P = 0.003 and P = 0.041). Meanwhile, both the TS (–) and TS (+) groups had lower frequencies of naïve cells (P = 0.001 for both) but higher frequencies of effector memory cells (P = 0.004 and P = 0.002) than did the healthy control group.ConclusionsThe Tregs of the TS patients could not efficiently suppress the proliferation of autologous effector T cells, despite their increased frequency in peripheral CD4+ T cells.

Upregulation of a potential prognostic biomarker, miR-155, enhances cell proliferation in patients with oral squamous cell carcinoma

We sought to investigate the role and diagnostic value of microRNA 155 (miR-155) in OSCC patients. Using real-time quantitative polymerase chain reaction analysis, miR-155 expression levels were assessed in OSCC cell lines and a cancerous HB cell line. The correlation between miR-155 expression level and clinical parameters was analyzed in 46 patients with OSCC. In addition, the effects of miR-155 on OSCC cell proliferation were evaluated by modulating its expression using an miR-155 mimic and antisense miR-155. Significant upregulation of miR-155 was found in OSCC cell lines and in tissues of patients with OSCC. The receiver operator characteristic analysis indicated fair-to-good predictability. Overexpression of miR-155 correlated with the histologic grade (P = .033), and the upregulation of miR-155 enhanced OSCC cell proliferation. In OSSC, upregulation of miR-155 correlated with the histologic grade and can be used as a potential prognostic biomarker.

PGE2 Contributes to In vitro MSC‐Mediated Inhibition of Non‐Specific and Antigen‐Specific T Cell Proliferation in MS Patients

Current theories of multiple sclerosis (MS) induction and progression place autoreactive T cells in the focus of the pathogenesis. Mesenchymal/stromal stem cells (MSC) have become a promising alternative approach for pathogenic therapy of MS due to their immunomodulatory properties, underlying mechanisms of which are intensive study. The objective of the research was to investigate the contribution of PGE2 to MSC-mediated suppression in patients with MS using in vitro model of mitogen- and myelin-stimulated T cell cocultivation with autologous/allogeneic MSC. We have showed that PGE2 production depends on cell-to-cell contact of MSC and lymphocytes. The antigenic stimulation did not affect PGE2 production following cocultivation of MSC and PBMC, and it is the presence of MSC in cell culture that significantly increases PGE2 production irrespective of antigenic cultivation conditions. Simultaneously, PGE2 synthesis correlated with indexes of MSC-mediated suppression of mitogen- and myelin-stimulated T cell proliferation in patients with MS. No significant differences in PGE2 production by autologous and allogeneic MSC have been established. These results have demonstrated that in patients with MS, PGE2 is one of the possible factors of MSC immunosuppression. The interrelation between PGE2 concentrations and T cell proliferation suppression mediated by MSC may explain one of the immune mechanisms of cell therapy, which is crucial for the further proper use of MSC in MS research and pathogenic treatment.

HLA-DR15-derived self-peptides are involved in increased autologous T cell proliferation in multiple sclerosis

The HLA-DR15 haplotype confers the largest part of the genetic risk to develop multiple sclerosis, a prototypic CD4+ T cell-mediated autoimmune disease. The mechanisms how certain HLA-class II molecules functionally contribute to autoimmune diseases are still poorly understood, but probably involve shaping an autoimmune-prone T cell repertoire during central tolerance in the thymus and subsequently maintaining or even expanding it in the peripheral immune system. Self-peptides that are presented by disease-associated HLA-class II molecules most likely play important roles during both processes. Here, we examined the functional involvement of the HLA-DR15 haplotype in autologous proliferation in multiple sclerosis and the contribution of HLA-DR15 haplotype-derived self-peptides in an in vitro system. We observe increased autologous T cell proliferation in patients with multiple sclerosis in relation to the multiple sclerosis risk-associated HLA-DR15 haplotype. Assuming that the spectrum of self-peptides that is presented by the two HLA-DR15 allelic products is important for sustaining autologous proliferation we performed peptide elution and identification experiments from the multiple sclerosis-associated DR15 molecules and a systematic analysis of a DR15 haplotype-derived self-peptide library. We identify HLA-derived self-peptides as potential mediators of altered autologous proliferation. Our data provide novel insights about perturbed T cell repertoire dynamics and the functional involvement of the major genetic risk factor, the HLA-DR15 haplotype, in multiple sclerosis.

Reduction in plasma cell proliferation after initial therapy in newly diagnosed multiple myeloma measures treatment response and predicts improved survival

AbstractStandard myeloma treatment response criteria are determined principally by changes in the monoclonal protein. Reduction in the size of the proliferative component of malignant plasma cells may be an additional metric of assessing response to therapy. We retrospectively analyzed 176 patients with newly diagnosed myeloma with a measurable plasma cell labeling index (PCLI) at diagnosis and repeat measurement 4 months after initiation of therapy. PCLI response was defined as a ≥ 60% reduction. Baseline PCLI is an independent prognostic factor; therefore, we categorized patients into 3 groups: PCLI ≥ 3% (high), ≥ 1% (intermediate), and < 1% (low). Patients achieving a greater PCLI response had improved median overall survival of 54 months compared with 29 months in nonresponders (P = .02). Improved median overall survival with PCLI response occurred in the high initial PCLI group (28 vs 7 months; P = .003) and intermediate group (64 vs 24 months; P = .002). The application of PCLI response and serum M-spike response together provided further prognostic information. On multivariate analysis, the prognostic value of PCLI response was independent of β2-microglobulin, elevated creatinine, serum M-spike response, and baseline PCLI. We conclude that a significant reduction in plasma cell proliferation in patients with newly diagnosed myeloma is an important predictor of survival.

P15 Multiple defects of the immunoregulatory system contribute to the development of autoimmune hepatitis

IntroductionConcordance for autoimmune hepatitis (AIH) is rare within families, though non-hepatic autoimmune disorders are frequent among first degree relatives (FDR) of AIH patients. While a defect in immunoregulation has been...

The effect of metformin on cell proliferation in patients with endometrial cancer.

e15577 Background: Metformin, a widely used anti-diabetic drug, is thought to suppress oncogenesis and/or improve prognosis in a variety of malignancies. Diabetes-related metabolic disorders, obesity and insulin resistance are risk factors for endometrial cancer, and together form a potential target for metformin therapy. Thus, we assumed that metformin might have some impact on the prevention and treatment of endometrial cancer. We examined the influence of metformin on cell proliferation of human endometrial cancer cells in vitro and in vivo. Methods: The Ishikawa and HEC-IB endometrial cancer-cell lines were treated with metformin and cell-cycle progression was assessed by flow cytometry. Activation of the MAPK, AMPK and mTOR signalling pathways as well as cell-cycle proteins was evaluated by Western blotting. Changes in signalling pathways were also assessed in endometrial tissues obtained from 15 patients with stage I endometrial cancer who received metformin (1,500-2,250mg/day) for 21-28 days. Results: Metformin inhibited the growth of Ishikawa and HEC-IB cells in a dose- and time-dependent fashion. The cell cycle was arrested at G0/G1 phase, with decreased cyclin D1 and phospho-pRB levels and increased p27Kip1 levels. Addition of metformin induced phosphorylation of AMPKa and de-phosphorylation of S6K1 and ERK1/2. siRNA-mediated knockdown of AMPKα failed to completely prevent the anti-proliferative activity of metformin, suggesting that metformin has AMPK independent effect on cell cycle. Metformin activity was also determined in patient-derived endometrial tissues. In western blotting, pre-operative metformin therapy showed same effect on cell line. Metformin effect of reducing the S6K1 phosphorylation and ERK1/2 phosphorylation were also identified in immunohistochemistry. Conclusions: The anti-neoplastic activity of metformin was demonstrated by in vitro and in vivo experiments. This effect is thought mTOR inhibition via AMPK and cell cycle regulation via AMPK independent pathway. This work gives the possibility for clinical application of endometrial cancer treatment using metformin.

PGE 2 decreases muscle cell proliferation in patients with non-asthmatic eosinophilic bronchitis

Non-asthmatic eosinophilic bronchitis (NAEB) is characterized by chronic cough and sputum eosinophilia without bronchial hyperresponsiveness. The aim of the present study is to determine whether increased levels of PGE 2 from NAEB sputum supernatants play a protective role in airway inflammation and muscular hyperplasia. Twenty-one patients with NAEB, 15 asthmatic patients, and 12 healthy subjects were studied. An up-regulated PGE 2 enzymatic pathway was observed in bronchial biopsies from patients with NAEB as compared with samples from asthmatic patients. Also, EP2 and EP4 receptor expression was increased in these samples. BSMC proliferation was inhibited to a greater extent in NAEB sputum supernatants than in those taken from asthmatic subjects and healthy controls. This inhibition was mostly due to PGE 2 levels, a fact which was confirmed by employing synthetic EP2 and EP4 agonist and antagonist receptors.These findings suggest that PGE 2 inhibits BSMC proliferation entailing a reduction of smooth muscle hyperplasia and thus protecting against the onset of airflow obstruction.

271 EXCESS DIETARY FOLATE INTAKE PROMOTES PROSTATE CARCINOGENESIS AND PROGRESSION IN AN IN VIVO MODEL OF TUMORIGENESIS

You have accessJournal of UrologyProstate Cancer: Basic Research1 Apr 2011271 EXCESS DIETARY FOLATE INTAKE PROMOTES PROSTATE CARCINOGENESIS AND PROGRESSION IN AN IN VIVO MODEL OF TUMORIGENESIS Jeffrey Tomaszewski, Jessica Cummings, Anil Parwani, Rajiv Dhir, Dean Bacich, and Denise O'Keefe Jeffrey TomaszewskiJeffrey Tomaszewski Pittsburgh, PA More articles by this author , Jessica CummingsJessica Cummings Pittsburgh, PA More articles by this author , Anil ParwaniAnil Parwani Pittsburgh, PA More articles by this author , Rajiv DhirRajiv Dhir Pittsburgh, PA More articles by this author , Dean BacichDean Bacich Pittsburgh, PA More articles by this author , and Denise O'KeefeDenise O'Keefe Pittsburgh, PA More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2011.02.363AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Recent studies demonstrate that folic acid supplementation is associated with an increased incidence of prostate cancer. We previously reported a positive correlation between serum and prostate tumor folate, and increased cancer cell proliferation in patients with higher serum folate concentrations. Our goal for this study was to determine the effect of dietary folate manipulation on prostate carcinogenesis and progression in an in vivo model. METHODS Prostate tumor and adjacent normal tissues from patients with prostate cancer were analyzed using the subrenal prostatic recapitulation model to determine the effect of dietary folate on tumor characteristics. Mice were randomly assigned to receive amino-acid defined diets which contained 0, 2 or 20mg/kg folic acid. Tissue recombinants (n=64) were serially grafted and harvested after 8, 16, and 24 weeks under the renal capsule. Histological and morphological features were assessed based upon 20 fields per recombinant, with the worst histological phenotype assigned to that recombinant. RESULTS Mice achieved serum folate levels that were consistent with the levels seen in human patients [i.e. approximately 2x adequate (24nM), 5x adequate (60nM) and 10 times adequate levels (120nM) for the 0, 2 and 20mg/kg folate diets, respectively]. Among normal prostate tissue recombinants, exposure to serum folate in the range of 5–10 fold adequate levels increased the incidence of PIN and adenocarcinoma when compared to recombinants grown in mice with serum folates 2-fold adequate levels (31.3% vs. 7%, respectively; p<0.05). An increased incidence of PIN and adenocarcinoma was also observed among prostate tumor recombinants in mice with 5–10 fold excess circulating folate when compared to the mice with 2-fold adequate levels (97.6% vs. 75.3%, respectively; p<0.05). CONCLUSIONS Modulation of dietary folate in an in vivo human prostate tissue recombinant model of tumorigenesis resulted in exposure to 5–10 fold excess levels of circulating folate, and promoted prostate carcinogenesis. © 2011 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 185Issue 4SApril 2011Page: e109 Advertisement Copyright & Permissions© 2011 by American Urological Association Education and Research, Inc.MetricsAuthor Information Jeffrey Tomaszewski Pittsburgh, PA More articles by this author Jessica Cummings Pittsburgh, PA More articles by this author Anil Parwani Pittsburgh, PA More articles by this author Rajiv Dhir Pittsburgh, PA More articles by this author Dean Bacich Pittsburgh, PA More articles by this author Denise O'Keefe Pittsburgh, PA More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Autocrine/paracrine cytokine stimulation of leukemic cell proliferation in smoldering and chronic adult T-cell leukemia

AbstractAdult T-cell leukemia (ATL), a heterogeneous disease, can be divided into smoldering, chronic, lymphoma, and acute types clinically. In addition to different clinical manifestations, different stages of ATL have different molecular signatures. Here, we demonstrated that smoldering/chronic ATL peripheral blood mononuclear cells spontaneously proliferated ex vivo in a cytokine (interleukin -12 [IL-12]/IL-9/IL-15)–dependent manner, while acute-type ATL peripheral blood mononuclear cells did not proliferate or proliferated independent of cytokines. Smoldering/chronic ATL cells produced IL-2 and IL-9 in 6-day ex vivo cultures. Interestingly, the addition of an anti–IL-2R-α monoclonal antibody profoundly inhibited IL-9 expression, suggesting optimal expression of IL-9 was dependent on IL-2 signaling in these patients. To determine whether there would be autonomous proliferation of ATL leukemic cells, we purified leukemic cells from patients with smoldering/chronic ATL. Purified leukemic cells cultured alone produced IL-2/IL-9, and the downstream Janus kinase/signal transducer and activator of transcription pathway was activated. However, the leukemic cells did not proliferate independently, but required coculture with autologous monocytes to induce proliferation. Moreover, interaction between leukemic cells and monocytes was contact dependent, and major histocompatibility complex class II expression may have contributed to this interaction. In conclusion, our data provide evidence that there is autocrine/paracrine cytokine stimulation of leukemic cell proliferation in patients with smoldering/chronic ATL that could be targeted for treatment.

Relationship between COX-2 and cell cycle-regulatory proteins in patients with esophageal squamous cell carcinoma.

To investigate the correlation between cyclooxygenase-2 (COX-2) and cell cycle-regulatory proteins in patients with esophageal squamous cell carcinoma (ESCC). One hundred and two surgically obtained specimens of ESCC were randomly collected. All specimens were obtained from patients who had not received chemo- or radiotherapy prior to surgical resection. Twenty-eight specimens of normal squamous epithelium served as controls. The expression of COX-2, Ki-67, cyclin A and p27 was examined by immunohistochemistry. The Pearson test was used to analyze the relationship between groups. The protein level of COX-2, Ki-67 and cyclin A was significantly higher in ESCC than in normal squamous epithelium (74.7 ± 61.2 vs 30.2 ± 43.4, 64.0 ± 51.6 vs 11.6 ± 2.3, 44.2 ± 32.2 vs 11.7 ± 5.0, respectively, all P < 0.01). In contrast, the protein level of p27 was significantly lower in ESCC than in normal squamous epithelium (182.0 ± 69.0 vs 266.4 ± 28.0, P < 0.01). In ESCC, COX-2 expression was correlated with T stage, the score of T1-T2 stage was lower than that of T3-T4 stage (55.0 ± 42.3 vs 83.0 ± 66.5, P < 0.05), and Ki-67, cyclin A and p27 expressions were correlated with the tumor differentiation (43.8 ± 31.7 vs 98.4 ± 84.8, 32.0 ± 19.0 vs 54.1 ± 53.7, 206.2 ± 61.5 vs 123.5 ± 68.3, respectively, all P < 0.01). COX-2 expression was positively correlated to Ki-67, cyclin A and negatively correlated to p27 expression in ESCC (r = 0.270, 0.233 and -0.311, respectively, all P < 0.05). The expression of COX-2 is correlated with tumor cell invasion and is closely related to the cell proliferation in patients with ESCC.

Evidence of increased islet cell proliferation in patients with recent-onset type 1 diabetes

In adults, the rate of beta cell replication is normally very low, but recent evidence suggests that it may increase during insulitis. We therefore studied tissue from donors with recent-onset type 1 diabetes to establish whether islet cell proliferation is increased during the disease process. Paraffin-embedded pancreatic sections from ten donors with recent-onset type 1 diabetes and a range of relevant controls were stained by immunohistochemical techniques with antibodies against the proliferation markers Ki67 and minichromosome maintenance protein-2 (MCM-2). A combination staining technique involving immunoperoxidase and immunofluorescence methods was developed to quantify the numbers of alpha and beta cells with Ki67-positive nuclei and to investigate the relationship between insulitis and islet cell proliferation. In non-diabetic control donors, only 1.1 +/- 0.3% (mean +/- SEM) of islets contained one or more Ki67(+) islet cells, whereas this proportion was increased markedly in recent-onset type 1 diabetes (10.88 +/- 2.5%; p < 0.005). An equivalent increase in Ki67(+) staining occurred in alpha and beta cells and was correlated positively with the presence of insulitis. A significant increase in the labelling of islet cells from type 1 diabetic donors was also seen when MCM-2 staining was employed. Increased islet cell proliferation was not evident in three donors with longer duration type 1 diabetes or in ten type 2 diabetic donors. Alpha and beta cells undergo a marked increase in proliferation during the progression of type 1 diabetes in humans. The results imply that islet cell proliferation is re-initiated in response to the autoimmune attack associated with type 1 diabetes.

Telomere Dysfunction and DNA Damage Checkpoints in Diseases and Cancer of the Gastrointestinal Tract

Telomere Dysfunction and DNA Damage Checkpoints in Diseases and Cancer of the Gastrointestinal Tract

Monocyte-derived dendritic cells from patients with severe forms of chromoblastomycosis induce CD4+ T cell activationin vitro

Dendritic cells (DCs) have been described as initiators and modulators of the immune response. Recently we have shown a predominant production of interleukin-10 cytokine, low levels of interferon-gamma and inefficient T cell proliferation in patients with severe forms of chromoblastomycosis. Chromoblastomycosis starts with subcutaneous inoculation of Fonsecaea pedrosoi into tissue where DCs are the first line of defence against this microorganism. In the present study, the interaction of F. pedrosoi and DCs obtained from patients with chromoblastomycosis was investigated. Our results showed that DCs from patients exhibited an increased expression of human leucocyte antigen D-related (HLA-DR) and co-stimulatory molecules. In the presence of conidia, the expression of HLA-DR and CD86 was up-regulated by DCs from patients and controls. Finally, we demonstrate the reversal of antigen-specific anergy and a T helper type 1 response mediated by DCs incubated with F. pedrosoi conidea.

Two Novel WT-1 Derived Peptides Induce CD4+ peptide–specific T Cell Proliferation in Patients with Myelodysplastic Syndrome (MDS)

The Wilms tumor gene WT1 is overexpressed in hematopoietic malignancies such as Myelodysplastic syndromes and leukemias and the WT1 protein was demonstrated to be an attractive target antigen for an immunotherapeutic approach to these diseases. Most of the efforts have been focused to the search for immunogenic peptides suitable for inducing cytotoxic T lymphocytes (CTLs) and to less extent for CD4+ T lymphocytes with potential cytotoxic activity. On this matter, in our previous experience with a p210-derived peptide vaccine developed for chronic myeloid leukemia patients with minimal residual disease, the main immune and therapeutic effect observed after vaccinations appeared to be mediated by peptide-specific CD4+ T cells induced by the longest peptide (25 mer) included in our vaccine. CML-peptide specific T cells were found to be either CD4+/perforin+ or CD4+/CD25+/Foxp3+ and we recently showed their direct cytotoxicity against a CML cell line. Thus to pursue a vaccine strategy mainly devoted to a similar CD4+ T cell immune response, we screened WT1 protein through Syfpeithi database to identify original peptides with a suitable length (23–25 amino acids) to be processed by several HLA class II molecules and to induce a strong CD4+ T cell stimulation. Additionally, in order to maximize the immunogenic potential of the novel peptides, we focused our attention on areas of the protein with known CTLs/CD4 T cells immunogenic epitopes. We identified two peptides that fulfilled these requirements: SEPQQMGSDVRDLNALLPAVPSLGG (WT1-iso5 64–88) which includes 5 amino acid from the alternative splicing derived isoform 5 of WT1 and the first 20 aa of “canonical” WT1 sequence and RPFMCAYPGCNKRYFKLSHLQMHSR (WT1321–345). Both 25mer peptides showed strong HLA binding properties for HLA-DRB1*0101, HLADRB1* 0401, HLA-DRB1*0701, HLA-DRB1*1101, HLA-DRB1*1501 and HLADRB1* 0301( DR17). We first tested them in vitro for their capability to induce peptide-specific CD4+ T cells. Briefly, CD4+ T cells freshly isolated from PBMC were cultured for 21 days in 5% AB human serum media while undergoing to 3 rounds of stimulation with autologous CD14+ cells and both WT1-iso5 64–88 and WT1 321–345 peptides at 20μg/ml in the presence of IL-15. This in vitro stimulation was performed in 3 normal subjects and in 3 MDS patients with high levels of bone marrow WT1 transcript (2 patients presenting a low-International Prognostic Scoring System (IPSS) refractory anemia (RA) and 1 with intermediate IPSS RA). In all 3 healthy donors tested, both peptides were able to induce peptide specific CD4+ T cell proliferation as measured by standard 3HThymidine assay, with a stimulation index (SI) ranging from 2.0 to 2.5 regardless of their HLA-DR phenotype ( SI= cpm CD4+ T cells plus test peptides/CD4+ T cell alone or CD4+ T cells plus control peptides; peptide-specific T cell proliferation was considered positive for SI≥2). Similar results were obtained in all 3 MDS patients in which WT1-iso5 64–88 and WT1 321–345 induced peptide-specific CD4+ T cell proliferation with a SI value of 2.5, 2.9 and 3.0 respectively. In conclusion the present study identified 2 novel WT1-derived 25 mer peptides which were able to easily induce in vitro a peptide-specific CD4+ T cell response in MDS patients. WT1-specific CD4+ T cells proliferated with similar SI values in normal donors and in WT1 positive MDS patients, the latter being highly exposed to this antigen and thus potentially tolerant to it. A possible cytotoxic activity of these WT1-specific CD4+ T cells is under evaluation and in vivo vaccinations of low-intermediate IPSS MDS patients with these peptides are planned.

The Importance of the Omega-6/Omega-3 Fatty Acid Ratio in Cardiovascular Disease and Other Chronic Diseases

Several sources of information suggest that human beings evolved on a diet with a ratio of omega-6 to omega-3 essential fatty acids (EFA) of approximately 1 whereas in Western diets the ratio is 15/1-16.7/1. Western diets are deficient in omega-3 fatty acids, and have excessive amounts of omega-6 fatty acids compared with the diet on which human beings evolved and their genetic patterns were established. Excessive amounts of omega-6 polyunsaturated fatty acids (PUFA) and a very high omega-6/omega-3 ratio, as is found in today's Western diets, promote the pathogenesis of many diseases, including cardiovascular disease, cancer, and inflammatory and autoimmune diseases, whereas increased levels of omega-3 PUFA (a lower omega-6/omega-3 ratio), exert suppressive effects. In the secondary prevention of cardiovascular disease, a ratio of 4/1 was associated with a 70% decrease in total mortality. A ratio of 2.5/1 reduced rectal cell proliferation in patients with colorectal cancer, whereas a ratio of 4/1 with the same amount of omega-3 PUFA had no effect. The lower omega-6/omega-3 ratio in women with breast cancer was associated with decreased risk. A ratio of 2-3/1 suppressed inflammation in patients with rheumatoid arthritis, and a ratio of 5/1 had a beneficial effect on patients with asthma, whereas a ratio of 10/1 had adverse consequences. These studies indicate that the optimal ratio may vary with the disease under consideration. This is consistent with the fact that chronic diseases are multigenic and multifactorial. Therefore, it is quite possible that the therapeutic dose of omega-3 fatty acids will depend on the degree of severity of disease resulting from the genetic predisposition. A lower ratio of omega-6/omega-3 fatty acids is more desirable in reducing the risk of many of the chronic diseases of high prevalence in Western societies, as well as in the developing countries.