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After antigenic challenge, B cells enter the dark zone (DZ) of germinal centers (GCs) to proliferate and hypermutate their immunoglobulin genes. Mutants with greater affinity for the antigen are positively selected in the light zone (LZ) to either differentiate into plasma and memory cells or reenter the DZ. The molecular circuits that govern positive selection in the GC are not known. We show here that the GC reaction required biphasic regulation of expression of the cell-cycle regulator c-Myc that involved its transient induction during early GC commitment, its repression by Bcl-6 in DZ B cells and its reinduction in B cells selected for reentry into the DZ. Inhibition of c-Myc in vivo led to GC collapse, which indicated an essential role for c-Myc in GCs. Our results have implications for the mechanism of GC selection and the role of c-Myc in lymphomagenesis.
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Linfócitos B/metabolismo , Genes myc/imunologia , Centro Germinativo/metabolismo , Proteínas Proto-Oncogênicas c-bcl-6/genética , Animais , Antígenos CD/genética , Antígenos CD/imunologia , Linfócitos B/imunologia , Linfócitos B/patologia , Ciclo Celular/genética , Ciclo Celular/imunologia , Movimento Celular , Proliferação de Células , Transformação Celular Neoplásica/genética , Transformação Celular Neoplásica/imunologia , Regulação da Expressão Gênica , Genes Reporter , Centro Germinativo/imunologia , Centro Germinativo/patologia , Proteínas de Fluorescência Verde , Linfoma/genética , Linfoma/metabolismo , Linfoma/patologia , Camundongos , Camundongos Transgênicos , Proteínas Proto-Oncogênicas c-bcl-6/imunologia , Receptores de Antígenos de Linfócitos B/genética , Receptores de Antígenos de Linfócitos B/imunologia , Transdução de Sinais , Linfócitos T/imunologia , Linfócitos T/metabolismo , Linfócitos T/patologiaRESUMO
OBJECTIVE: We recently characterized the clinical performance of a multivariate index assay (MIA3G) to assess ovarian cancer risk for adnexal masses at initial presentation. This study evaluated how MIA3G varies when applied longitudinally to monitor risk during clinical follow-up. METHOD: The study evaluated women presenting with adnexal masses from eleven centers across the US. Patients received an initial blood draw at enrollment and at the standard-of-care follow-up visits. MIA3G was determined for all visits but physicians did not have access to MIA3G scores to determine clinical management. The primary outcome was the relative change value (RCV) of MIA3G over the period of clinical observation. RESULTS: A total of 510 patients of 785 enrolled met study criteria. Of these, 30.8% had a second, 25.4% a third and 22.2% a fourth blood draw following initial collection. The median duration from initial draw was 131 d to second draw, 301.5 d to the third draw and 365.5 d to the fourth draw. MIA3G RCV of >50% was observed in 22-26% patients, whereas 70-75% patients had MIA3G RCV >5%. An empirical baseline RCV of 56% - transformed to 1 in logarithmic scale - was calculated from averaging RCVs of all patients who had no malignancy risk after 210 days. RCV > 1 log was associated with higher incidence of surgical intervention (29.6%) compared to RCV < 1 log (16.9%). CONCLUSIONS: Variation in MI3AG does not change the accuracy of the test for excluding malignancy, while marked changes may be associated with a slightly higher likelihood of surgical intervention. In addition to MIA3G score itself, the MIA3G RCV may be important for clinical management.
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Neoplasias Ovarianas , Humanos , Feminino , Neoplasias Ovarianas/sangue , Neoplasias Ovarianas/diagnóstico , Pessoa de Meia-Idade , Estudos Longitudinais , Adulto , Idoso , Medição de Risco/métodos , Biomarcadores Tumorais/sangue , Análise Multivariada , Idoso de 80 Anos ou mais , Proteína 2 do Domínio Central WAP de Quatro DissulfetosRESUMO
BACKGROUND: To determine differentially expressed and spliced RNA transcripts in chronic lymphocytic leukemia specimens a high throughput RNA-sequencing (HTS RNA-seq) analysis was performed. METHODS: Ten CLL specimens and five normal peripheral blood CD19+ B cells were analyzed by HTS RNA-seq. The library preparation was performed with Illumina TrueSeq RNA kit and analyzed by Illumina HiSeq 2000 sequencing system. RESULTS: An average of 48.5 million reads for B cells, and 50.6 million reads for CLL specimens were obtained with 10396 and 10448 assembled transcripts for normal B cells and primary CLL specimens respectively. With the Cuffdiff analysis, 2091 differentially expressed genes (DEG) between B cells and CLL specimens based on FPKM (fragments per kilobase of transcript per million reads and false discovery rate, FDR q < 0.05, fold change >2) were identified. Expression of selected DEGs (n = 32) with up regulated and down regulated expression in CLL from RNA-seq data were also analyzed by qRT-PCR in a test cohort of CLL specimens. Even though there was a variation in fold expression of DEG genes between RNA-seq and qRT-PCR; more than 90 % of analyzed genes were validated by qRT-PCR analysis. Analysis of RNA-seq data for splicing alterations in CLL and B cells was performed by Multivariate Analysis of Transcript Splicing (MATS analysis). Skipped exon was the most frequent splicing alteration in CLL specimens with 128 significant events (P-value <0.05, minimum inclusion level difference >0.1). CONCLUSION: The RNA-seq analysis of CLL specimens identifies novel DEG and alternatively spliced genes that are potential prognostic markers and therapeutic targets. High level of validation by qRT-PCR for a number of DEG genes supports the accuracy of this analysis. Global comparison of transcriptomes of B cells, IGVH non-mutated CLL (U-CLL) and mutated CLL specimens (M-CLL) with multidimensional scaling analysis was able to segregate CLL and B cell transcriptomes but the M-CLL and U-CLL transcriptomes were indistinguishable. The analysis of HTS RNA-seq data to identify alternative splicing events and other genetic abnormalities specific to CLL is an added advantage of RNA-seq that is not feasible with other genome wide analysis.
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Processamento Alternativo/genética , Sequenciamento de Nucleotídeos em Larga Escala , Leucemia Linfocítica Crônica de Células B/genética , Splicing de RNA/genética , Idoso , Idoso de 80 Anos ou mais , Linfócitos B/metabolismo , Linfócitos B/patologia , Éxons/genética , Feminino , Perfilação da Expressão Gênica , Regulação Leucêmica da Expressão Gênica , Humanos , Leucemia Linfocítica Crônica de Células B/patologia , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Análise de Sequência de RNA , Transcriptoma/genéticaRESUMO
BACKGROUND: Key effector(s) of mutated KRAS in lung cancer progression and metastasis are unknown. Here we investigated the role of PAK1/Crk axis in transduction of the oncogenic KRAS signal in non-small cell lung cancer (NSCLC). METHODS: We used NSCLC clinical specimens to examine the correlation among KRAS mutations (codon 12, 13 and 61); PAK1/Crk axis activation [p-PAK1(Thr423), p-Crk(Ser41)]; and adhesion molecules expression by immunohistochemistry. For assessing the role of proto-oncogene c-Crk as a KRAS effector, we inhibited KRAS in NSCLC cells by a combination of farnesyltransferase inhibitor (FTI) and geranylgeranyltransferase inhibitor (GGTI) and measured p-Crk-II(Ser41) by western blotting. Finally, we disrupted the signaling network downstream of KRAS by blocking KRAS/PAK1/Crk axis with PAK1 inhibitors (i.e., IPA-3, FRAX597 or FRAX1036) along with partial inhibition of all other KRAS effectors by prenylation inhibitors (FTI + GGTI) and examined the motility, morphology and proliferation of the NSCLC cells. RESULTS: Immunohistochemical analysis demonstrated an inverse correlation between PAK1/Crk phosphorylation and E-cadherin/p120-catenin expression. Furthermore, KRAS mutant tumors expressed higher p-PAK1(Thr423) compared to KRAS wild type. KRAS prenylation inhibition by (FTI + GGTI) completely dephosphorylated proto-oncogene c-Crk on Serine 41 while Crk phosphorylation did not change by individual prenylation inhibitors or diluent. Combination of PAK1 inhibition and partial inhibition of all other KRAS effectors by (FTI + GGTI) dramatically altered morphology, motility and proliferation of H157 and A549 cells. CONCLUSIONS: Our data provide evidence that proto-oncogene c-Crk is operative downstream of KRAS in NSCLC. Previously we demonstrated that Crk receives oncogenic signals from PAK1. These data in conjunction with the work of others that have specified the role of PAK1 in transduction of KRAS signal bring forward the importance of KRAS/PAK1/Crk axis as a prominent pathway in the oncogenesis of KRAS mutant lung cancer.
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Carcinoma Pulmonar de Células não Pequenas/metabolismo , Neoplasias Pulmonares/metabolismo , Proteínas Proto-Oncogênicas c-crk/metabolismo , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , Quinases Ativadas por p21/metabolismo , Caderinas , Carcinogênese , Carcinoma Pulmonar de Células não Pequenas/genética , Cateninas , Linhagem Celular Tumoral , Proliferação de Células , Regulação Neoplásica da Expressão Gênica/fisiologia , Humanos , Neoplasias Pulmonares/genética , Fosforilação , Prenilação , Proto-Oncogene Mas , Proteínas Proto-Oncogênicas c-crk/genética , Proteínas Proto-Oncogênicas p21(ras)/genética , Transdução de Sinais/fisiologia , Quinases Ativadas por p21/genética , delta CateninaRESUMO
Background: Surgery remains the main treatment option for an adnexal mass suspicious of ovarian cancer. The malignancy rate is, however, only 10-15% in women undergoing surgery. This results in a high number of unnecessary surgeries. A surveillance-based approach is recommended to form the basis for surgical referrals. We have previously reported the clinical performance of MIA3G, a deep neural network-based algorithm, for assessing ovarian cancer risk. In this study, we show that MIA3G markedly improves the surgical selection for women presenting with adnexal masses. Methods: MIA3G employs seven serum biomarkers, patient age, and menopausal status. Serum samples were collected from 785 women (IQR: 39-55 years) across 12 centers that presented with adnexal masses. MIA3G risk scores were calculated for all subjects in this cohort. Physicians had no access to the MIA3G risk score when deciding upon a surgical referral. The performance of MIA3G for surgery referral was compared to clinical and surgical outcomes. MIA3G was also tested in an independent cohort comprising 29 women across 14 study sites, in which the physicians had access to and utilized MIA3G prior to surgical consideration. Results: When compared to the actual number of surgeries (n = 207), referrals based on the MIA3G score would have reduced surgeries by 62% (n = 79). The reduction was higher in premenopausal patients (77%) and in patients ≤55 years old (70%). In addition, a 431% improvement in malignancy prediction would have been observed if physicians had utilized MIA3G scores for surgery selection. The accuracy of MIA3G referral was 90.00% (CI 87.89-92.11), while only 9.18% accuracy was observed when the MIA3G score was not used. These results were corroborated in an independent multi-site study of 29 patients in which the physicians utilized MIA3G in surgical consideration. The surgery reduction was 87% in this cohort. Moreover, the accuracy and concordance of MIA3G in this independent cohort were each 96.55%. Conclusion: These findings demonstrate that MIA3G markedly augments the physician's decisions for surgical intervention and improves malignancy prediction in women presenting with adnexal masses. MIA3G utilization as a clinical diagnostic tool might help reduce unnecessary surgeries.
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Neoplasias da Mama/genética , Carcinoma Lobular/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias da Mama/patologia , Carcinoma Lobular/patologia , Receptores ErbB/genética , Éxons , Feminino , Humanos , Metástase Linfática/genética , Pessoa de Meia-Idade , Proteínas Proto-Oncogênicas B-raf/genética , Proteínas Proto-Oncogênicas p21(ras)/genética , Deleção de Sequência , Neoplasias de Mama Triplo Negativas/genética , Neoplasias de Mama Triplo Negativas/patologiaRESUMO
Background: Conservative management of adnexal mass is warranted when there is imaging-based and clinical evidence of benign characteristics. Malignancy risk is, however, a concern due to the mortality rate of ovarian cancer. Malignancy occurs in 10-15% of adnexal masses that go to surgery, whereas the rate of malignancy is much lower in masses clinically characterized as benign or indeterminate. Additional diagnostic tests could assist conservative management of these patients. Here we report the clinical validation of OvaWatch, a multivariate index assay, with real-world evidence of performance that supports conservative management of adnexal masses. Methods: OvaWatch utilizes a previously characterized neural network-based algorithm combining serum biomarkers and clinical covariates and was used to examine malignancy risk in prospective and retrospective samples of patients with an adnexal mass. Retrospective data sets were assembled from previous studies using patients who had adnexal mass and were scheduled for surgery. The prospective study was a multi-center trial of women with adnexal mass as identified on clinical examination and indeterminate or asymptomatic by imaging. The performance to detect ovarian malignancy was evaluated at a previously validated score threshold. Results: In retrospective, low prevalence (N = 1,453, 1.5% malignancy rate) data from patients that received an independent physician assessment of benign, OvaWatch has a sensitivity of 81.8% [95% confidence interval (CI) 65.1-92.7] for identifying a histologically confirmed malignancy, and a negative predictive value (NPV) of 99.7%. OvaWatch identified 18/22 malignancies missed by physician assessment. A prospective data set had 501 patients where 106 patients with adnexal mass went for surgery. The prevalence was 2% (10 malignancies). The sensitivity of OvaWatch for malignancy was 40% (95% CI: 16.8-68.7%), and the specificity was 87% (95% CI: 83.7-89.7) when patients were included in the analysis who did not go to surgery and were evaluated as benign. The NPV remained 98.6% (95% CI: 97.0-99.4%). An independent analysis set with a high prevalence (45.8%) the NPV value was 87.8% (95% CI: 95% CI: 75.8-94.3%). Conclusion: OvaWatch demonstrated high NPV across diverse data sets and promises utility as an effective diagnostic test supporting management of suspected benign or indeterminate mass to safely decrease or delay unnecessary surgeries.
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Activation-induced cytidine deaminase (AID) is a single-stranded (ss) DNA-specific cytidine deaminase that initiates Ig heavy chain (IgH) class switch recombination (CSR) and Ig somatic hypermutation (SHM) by deaminating cytidines within, respectively, IgH switch (S) regions and Ig variable region (V) exons. AID that is phosphorylated on serine residue 38 interacts with replication protein A (RPA), a ssDNA binding protein, to promote deamination of transcribed double-stranded DNA in vitro, which, along with other evidence, suggests that AID may similarly gain access to transcribed S regions and V exons in vivo. However, the physiological role of AID phosphorylation at serine residue 38 (S38), and even the requirement for the S38 residue, with respect to CSR or SHM has been debated. To address this issue, we used gene targeting to generate an endogenous mouse AID locus that produces AID in which S38 is substituted with alanine (AID(S38A)), a mutant form of AID that retains similar catalytic activity on ssDNA as WT AID (AID(WT)). B cells homozygous for the AID(S38A) mutation show substantially impaired CSR and SHM, correlating with inability of AID(S38A) to interact with endogenous RPA. Moreover, mice haploinsufficient for AID(S38A) have even more severely impaired CSR when compared with mice haploinsufficient for AID(WT), with CSR levels reduced to nearly background levels. These results unequivocally demonstrate that integrity of the AID S38 phosphorylation site is required for normal CSR and SHM in mice and strongly support a role for AID phosphorylation at S38 and RPA interaction in regulating CSR and SHM.
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Citidina Desaminase/metabolismo , Switching de Imunoglobulina , Mutação , Recombinação Genética , Serina/metabolismo , Animais , Sequência de Bases , Citidina Desaminase/química , Primers do DNA , Éxons , Técnicas de Introdução de Genes , Imunoprecipitação , Camundongos , Camundongos Mutantes , Nódulos Linfáticos Agregados/enzimologia , Fosforilação , Reação em Cadeia da PolimeraseRESUMO
Aim: Allograft rejection remains a major cause of graft failure in kidney transplantation. Here the authors report the validation of a non-invasive molecular diagnostic assay, AlloMap Kidney, using peripheral blood. Methods: The AlloMap Kidney test is a gene expression profile utilizing the RNA-seq platform to measure immune quiescence in kidney transplant patients. Results/Conclusions: Analytical validation showed robust performance characteristics with an accuracy correlation coefficient of 0.997 and a precision coefficient of variation of 0.049 across testing. Clinical validation from the prospective, multi-center studies of 235 samples (66 rejection and 169 quiescence specimens) demonstrated the sensitivity of 70% and specificity of 66% for allograft rejection, while the negative predictive value was 95% to discriminate rejection from quiescence at 10% prevalence of rejection.
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Transplante de Rim , Rejeição de Enxerto/diagnóstico , Rejeição de Enxerto/genética , Humanos , Rim , Estudos Prospectivos , TranscriptomaRESUMO
PURPOSE: The purpose of the study was to measure the change in intraocular pressure (IOP) after micropulse laser trabeculoplasty (MLT) and to evaluate subgroups based on initial IOP and severity of glaucoma. METHODS: This was a retrospective study of 34 eyes that were treated with MLT. Follow-up measurements were obtained at 3 months. Paired t-tests compared baseline to follow-up. RESULTS: IOP reduction approached significance (P = 0.055) for lower mean IOP from pre- to post-treatment. In the subset of those with baseline IOP >16, mean IOP was significantly lower (P = 0.001) from pretreatment (mean = 19.43, standard deviation [SD] = 2.48) to posttreatment (mean = 16.91, SD = 3.37). There were 34.8% (8/23) with a 20% reduction from baseline IOP. For patients with no glaucoma/early glaucoma, mean IOP was significantly lower (P = 0.003) from pretreatment (mean = 19.62, SD = 3.36) to posttreatment (mean = 16.62, SD = 3.01). In the subset of those with moderate/advanced glaucoma, there were no significant changes for mean IOP from pretreatment to posttreatment. CONCLUSION: Patients with higher initial IOP and in the early stages of glaucoma were more likely to benefit from MLT in lowering IOP. A randomized clinical trial is necessary to confirm these preliminary findings. We recommend that clinicians should consider MLT in the management of early glaucoma and among those with IOP >16 mmHg.
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PURPOSE: To provide safety and effectiveness outcomes 12 months postsurgically for sequential canaloplasty and trabeculotomy with the OMNI system combined with cataract surgery in mild-to-moderate open-angle glaucoma (OAG). SETTING: Eleven ophthalmology practices and surgery centers located in 8 U.S. states. DESIGN: Retrospective, multicenter, single arm. METHODS: Twelve surgeons contributed 81 patients meeting eligibility criteria: OAG, 12-month follow-up, and medicated intraocular pressure (IOP) 36 mm Hg or less on 4 or less medications preoperatively. Analysis was stratified by baseline IOP: more than 18 mm Hg (Group 1) and 18 mm Hg (Group 2) or less. Success was defined as proportion with 20% reduction or greater in IOP or IOP between 6 and 18 mm Hg (inclusive) and on the same or fewer medications without secondary surgical intervention (SSI). Other endpoints included mean IOP and medications at 12 months. Safety included corrected distance visual acuity and adverse events (AEs). RESULTS: Of the 81 patients included, primary success was met by 79% in Group 1 and 81% in Group 2. The mean IOP was reduced in Group 1 (21.9 to 15.1 mm Hg, P < .0001) and remained controlled in Group 2 (14.1 to 13.4 mm Hg, P = .3177). Medications went from 2.0 ± 1.3 to 1.1 ± 1.1 in Group 1 and from 1.6 ± 1.3 to 0.9 ± 1.2 in Group 2. AEs were typical for cataract or angle surgery: mild inflammation (11%), IOP spikes (5%), and hyphema (4%). Four patients (5%) required an SSI. CONCLUSIONS: The OMNI system provided effective IOP reduction, sustained IOP control, and meaningful medication reduction for up to 12 months postoperative.
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Catarata , Glaucoma de Ângulo Aberto , Oftalmologia , Trabeculectomia , Catarata/complicações , Glaucoma de Ângulo Aberto/cirurgia , Humanos , Pressão Intraocular , Estudos Retrospectivos , Resultado do TratamentoRESUMO
The human proto-oncogene BCL6 encodes a BTB/POZ-zinc-finger transcriptional repressor that is necessary for germinal-centre formation and is implicated in the pathogenesis of B-cell lymphoma. The precise function of BCL6 in germinal-centre development and lymphomagenesis is unclear because very few direct BCL6 target genes have been identified. Here we report that BCL6 suppresses the expression of the p53 (also known as tp53) tumour suppressor gene and modulates DNA damage-induced apoptotic responses in germinal-centre B cells. BCL6 represses p53 transcription by binding two specific DNA sites within the p53 promoter region and, accordingly, p53 expression is absent in germinal-centre B cells where BCL6 is highly expressed. Suppression of BCL6 expression via specific short interfering RNA leads to increased levels of p53 messenger RNA and protein both under basal conditions and in response to DNA damage. Most notably, constitutive expression of BCL6 protects B cell lines from apoptosis induced by DNA damage. These results suggest that an important function of BCL6 is to allow germinal-centre B cells to tolerate the physiological DNA breaks required for immunoglobulin class switch recombination and somatic hypermutation without inducing a p53-dependent apoptotic response. These findings also imply that deregulated BCL6 expression contributes to lymphomagenesis in part by functional inactivation of p53.
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Linfócitos B/metabolismo , Proteínas de Ligação a DNA/metabolismo , Regulação para Baixo , Centro Germinativo/citologia , Regiões Promotoras Genéticas/genética , Proteínas Proto-Oncogênicas/metabolismo , Proteínas Repressoras/metabolismo , Fatores de Transcrição/metabolismo , Proteína Supressora de Tumor p53/genética , Apoptose , Linhagem Celular , Dano ao DNA , Proteínas de Ligação a DNA/genética , Inativação Gênica , Genes Reporter/genética , Centro Germinativo/imunologia , Humanos , Proto-Oncogene Mas , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas c-bcl-6 , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Proteínas Repressoras/genética , Fatores de Transcrição/genética , Transcrição Gênica/genética , Proteína Supressora de Tumor p53/biossínteseRESUMO
INTRODUCTION: Student-run free clinics (SRFCs) have become important primary care homes during the COVID-19 pandemic. With students pulled from clinical sites, funding deficits, SRFCs' voluntary nature, and no best practices for telehealth SRFCs, many have been forced to close. This report shares a systematic approach for implementing a telehealth clinic along with initial outcomes from the Dedicated to Aurora's Wellness and Needs (DAWN) SRFC. METHODS: We utilized pilots with students, community volunteers, and patients to identify a telehealth platform. We implemented weekly plan-do-study-act (PDSA) cycles to develop a feasible interprofessional telehealth model. Key PDSA cycle goals included seamless utilization of platform, identification of necessary team members, appropriate scheduling of patients and volunteers, integration of interprofessional learners, positive patient and volunteer experience, and process for identifying and addressing patient social needs. Measured outcomes included total visits, no-show rates, and chief complaints addressed. RESULTS: Outcomes from PDSA cycles included a resultant telehealth clinic team and model, workflow for outreach for social needs screening and navigation, and team training guides. Visit data and no-show rates from January 2020 through July 2020 demonstrated total visits returned to 60% of pre-COVID numbers while no-show rates decreased significantly below pre-COVID rates. A range of acute and chronic concerns were successfully managed via telehealth. CONCLUSION: SRFCs are poised to continue serving an important role in caring for the country's most vulnerable populations. The DAWN telehealth implementation process, outcomes, and resultant protocols may help inform other SRFCs seeking to establish telehealth services.
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To mount an optimum immune response, mature B lymphocytes can change the class of expressed antibody from IgM to IgG, IgA, or IgE through a recombination/deletion process termed immunoglobulin heavy chain (IgH) class switch recombination (CSR). CSR requires the activation-induced cytidine deaminase (AID), which has been shown to employ single-stranded DNA as a substrate in vitro. IgH CSR occurs within and requires large, repetitive sequences, termed S regions, which are parts of germ line transcription units (termed "C(H) genes") that are composed of promoters, S regions, and individual IgH constant region exons. CSR requires and is directed by germ line transcription of participating C(H) genes prior to CSR. AID deamination of cytidines in S regions appears to lead to S region double-stranded breaks (DSBs) required to initiate CSR. Joining of two broken S regions to complete CSR exploits the activities of general DNA DSB repair mechanisms. In this chapter, we discuss our current knowledge of the function of S regions, germ line transcription, AID, and DNA repair in CSR. We present a model for CSR in which transcription through S regions provides DNA substrates on which AID can generate DSB-inducing lesions. We also discuss how phosphorylation of AID may mediate interactions with cofactors that facilitate access to transcribed S regions during CSR and transcribed variable regions during the related process of somatic hypermutation (SHM). Finally, in the context of this CSR model, we further discuss current findings that suggest synapsis and joining of S region DSBs during CSR have evolved to exploit general mechanisms that function to join widely separated chromosomal DSBs.
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Citidina Desaminase/fisiologia , Switching de Imunoglobulina/genética , Cadeias Pesadas de Imunoglobulinas/genética , Hipermutação Somática de Imunoglobulina/genética , Animais , Linfócitos B/imunologia , Evolução Biológica , Quebras de DNA de Cadeia Dupla , Reparo do DNA , HumanosRESUMO
Ovarian cancer, the most deadly gynecological malignancy in U.S. women, metastasizes uniquely, spreading through the peritoneal cavity and often generating widespread metastatic sites before diagnosis. The vast majority of ovarian cancer cases occur in women over 40 and the median age at diagnosis is 63. Additionally, elderly women receive poorer prognoses when diagnosed with ovarian cancer. Despite age being a significant risk factor for the development of this cancer, there are little published data which address the impact of aging on ovarian cancer metastasis. Here we report that the aged host is more susceptible to metastatic success using two murine syngeneic allograft models of ovarian cancer metastasis. This age-related increase in metastatic tumor burden corresponds with an increase in tumor infiltrating lymphocytes (TILs) in tumor-bearing mice and alteration of B cell-related pathways in gonadal adipose tissue. Based on this work, further studies elucidating the status of B cell TILs in mouse models of metastasis and human tumors in the context of aging are warranted.
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Tecido Adiposo/patologia , Envelhecimento/patologia , Aloenxertos/patologia , Metástase Neoplásica/patologia , Neoplasias Ovarianas/patologia , Adulto , Idoso , Animais , Linhagem Celular , Feminino , Humanos , Linfócitos do Interstício Tumoral/patologia , Camundongos , Camundongos Endogâmicos C57BL , Pessoa de Meia-Idade , Prognóstico , Fatores de Risco , Carga Tumoral/fisiologia , Adulto JovemRESUMO
Immunoglobulin gene diversification by somatic hypermutation (SHM), class switch recombination (CSR), and gene conversion is dependent upon activation-induced cytidine deaminase (AID). AID is a single-stranded DNA specific cytidine deaminase that is expressed primarily in activated mature B lymphocytes. AID appears to catalyze DNA cytidine deamination of immunoglobulin heavy (IgH) and light chain (IgL) variable region (V) exons and IgH switch (S) region sequences to initiate, respectively, IgH and IgL somatic hypermutation (SHM) and IgH class switch recombination (CSR). Here, we will discuss the implications of recent studies that demonstrate the role of AID phosphorylation in augmenting AID activity with respect to these two processes.
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Citidina Desaminase/metabolismo , Animais , Linfócitos B/enzimologia , Catálise , Desaminação , Citometria de Fluxo , Humanos , Fosforilação , Processamento de Proteína Pós-TraducionalRESUMO
PURPOSE: The incidence of cytomegalovirus (CMV) retinitis in the pediatric allogeneic hematopoietic stem cell transplant (HSCT) population is unknown. We report a cluster of 5 pediatric patients with CMV retinitis diagnosed in a 12-month period and compare this to the rate of CMV viremia and retinitis in the 4 years prior. Presented is the ophthalmic screening protocol developed in response to this experience. DESIGN: Retrospective cross-sectional study. METHODS: A retrospective chart review was performed on patients at Children's Hospital of Colorado (CHCO) who received allogeneic HSCT between January 2010 and December 2014. Fisher exact test was used to compare the proportion of CMV viremia and CMV retinitis in patients transplanted between January 2010 and December 2013 with those transplanted in 2014. RESULTS: A total of 101 patients underwent allogeneic HSCT from January 2010 to December 2013; 32 (32%) tested positive for CMV viremia. No cases of CMV retinitis were identified. From January 2014 to December 2014, 28 patients underwent allogeneic HSCT; 13 patients (46%) had CMV viremia, not a statistically significant increase (P = .18). There were 5 cases of CMV retinitis diagnosed in those transplanted in 2014, a statistically significant increase compared with those transplanted in 2010-2013 (P = .0004). A multidisciplinary team was formed to review the literature and an ophthalmic screening protocol was developed. CONCLUSION: Our recent cluster of CMV retinitis in pediatric allogeneic HSCT patients may suggest a rise in incidence of CMV retinitis. We propose an ophthalmic screening protocol to diagnose retinitis in pediatric HSCT patients in the early, often asymptomatic stage.
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Retinite por Citomegalovirus/epidemiologia , Citomegalovirus/genética , DNA Viral/análise , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Complicações Pós-Operatórias/epidemiologia , Adolescente , Criança , Pré-Escolar , Colorado/epidemiologia , Estudos Transversais , Retinite por Citomegalovirus/diagnóstico , Seguimentos , Neoplasias Hematológicas/cirurgia , Humanos , Incidência , Masculino , Oftalmoscopia , Reação em Cadeia da Polimerase , Estudos Retrospectivos , Transplante Homólogo , Carga ViralRESUMO
The Hematopathology Molecular Genetics subcommittee presents recommendations for molecular diagnostic testing in acute myeloid leukemia, myeloproliferative neoplasms, myelodysplastic syndrome, and lymphomas and for the development of an interfacility consultation service.
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Ovarian cancer is the fifth leading cause of cancer deaths in U.S. women and the deadliest gynecologic malignancy. This lethality is largely due to the fact that most cases are diagnosed at metastatic stages of the disease when the prognosis is poor. Epidemiologic studies consistently demonstrate that parous women have a reduced risk of developing ovarian cancer, with a greater number of births affording greater protection; however little is known about the impact of parity on ovarian cancer metastasis. Here we report that multiparous mice are less susceptible to ovarian cancer metastasis in an age-matched syngeneic murine allograft model. Interferon pathways were found to be upregulated in healthy adipose tissue of multiparous mice, suggesting a possible mechanism for the multiparous-related protective effect against metastasis. This protective effect was found to be lost with age. Based on this work, future studies exploring therapeutic strategies which harness the multiparity-associated protective effect demonstrated here are warranted.
Assuntos
Tecido Adiposo/metabolismo , Interferons/metabolismo , Neoplasias Epiteliais e Glandulares/patologia , Neoplasias Ovarianas/patologia , Paridade , Peritônio/metabolismo , Tecido Adiposo/patologia , Aloenxertos , Animais , Carcinoma Epitelial do Ovário , Modelos Animais de Doenças , Suscetibilidade a Doenças , Feminino , Camundongos , Camundongos Endogâmicos C57BL , Metástase Neoplásica , Transplante de Neoplasias , Neoplasias Epiteliais e Glandulares/metabolismo , Neoplasias Ovarianas/metabolismo , Neoplasias Peritoneais/metabolismo , Neoplasias Peritoneais/prevenção & controle , Neoplasias Peritoneais/secundário , Peritônio/patologia , Gravidez , Fatores de RiscoRESUMO
KRAS mutation status predicts response to anti-EGFR therapy in colorectal cancer patients. Here we report an interesting case of discordant KRAS mutation status in a patient with two separate tumour foci. Tumour A in sigmoid colon invaded through muscularis propria into the subserosal fat with metastatic disease in regional lymph nodes (pT3N2b). Tumour B in ascending colon had a relatively lower stage and no metastasis (pT2N0). Both tumours showed similar morphology, immunohistochemical staining and microsatellite instability pattern. KRAS mutation, however, was detected only in tumour A. These findings indicate distinct clonal nature of these two tumours. The discordance of KRAS mutation status also suggests that a combination of anti-epidermal growth factor receptor and chemotherapy is likely the best treatment option for this patient. This case exemplifies a notion that comprehensive pathological work-up comprising molecular testing is critical to guide the diagnosis and treatment decisions for colorectal cancer patients with multiple tumours.