Hepatosplenic T-Cell Lymphoma Mimicking Acute Onset of Cholestatic Hepatitis in a Young Immunocompetent Man: A Case Report

We herein report a case of hepatosplenic T-cell lymphoma (HSTCL) incidentally found in a 30-year-old man who came to the emergency department after an ankle trauma. At admission, laboratory tests revealed abnormal liver enzymes and pancytopenia, and imaging showed mild hepatosplenomegaly. During hospitalization, the patient's clinical condition worsened rapidly, with a concomitant increase in cholestatic enzymes, severe jaundice, and the worsening of pancytopenia. Causes of liver injury, including many infectious diseases, were explored until the diagnosis of HSTCL was made by liver and bone marrow biopsies. Subsequently, the patient underwent six cycles of chemotherapy with a CHOP (cyclophosphamide, hydroxydaunorubicin, oncovin and prednisone or prednisolone) regimen and one with Hyper-CVAD (fractionated cyclophosphamide, vincristine, doxorubicin, dexamethasone) but, despite this aggressive treatment, died due to disease progression 2 months after diagnosis. This rare disease should be considered in the diagnostic workup of acute cholestatic hepatitis presenting with concomitant hepatosplenomegaly and cytopenia

Anti-miR-135b in colon cancer treatment: Results from a preclinical study.

Background: MicroRNAs (miRs) are small non coding RNAs involved in cell homeostasis. miRs are deregulated in colorectal cancer (CRC). Our study aimed at identifying miRs with a driver role in carcinogenesis altered by similar mechanisms in both human and mouse CRC. Goal of the study was to use CRC mouse models for the pre-clinical development of anti-miRs as therapeutic drugs. Methods: Azoximetane (AOM)/Dextran-Sulfate (DSS) treated mice or CDX2Cre-APC f/wt mice were used to study inflammation-associated and sporadic APC-related CRC. Human Inflammatory Bowel Disease associated (n=15), and sporadic (n=62) CRC with their matched normal tissues were collected according to Good Clinical Practice recommendation and subjected to RNA extraction using Trizol. miR and gene expression profiling was assessed by nCounter technology (Nanostring Seattle). Anti-miR-135b and scrambled probes for in vivo studies were synthesized by Girindus. Results: miRs profiling from AOM/DSS and CDX2Cre-APC f/wt CRC revealed that miR-135b is one of the most up-regulated miRs in both models. In humans miR-135b over-expression was found in both IBD and sporadic CRC and was associated with reduced Progression Free Survival and Overall Survival in CRC patients. Molecular studies in Mouse Embryo Fibroblast and human CRC cell lines highlighted the role of two major pathways in the upstream activation of miR-135b: APC-β-Catenin and SRC-PI3K. MiR-135b up-regulation resulted in reduced apoptosis and increased cell growth due to the down-regulation of TGFRB2, DAPK1, APC and FIH. Silencing of miR-135b in vivo reduced tumor multiplicity and tumor load in the AOM/DSS CRC model. Mice treated with anti-miR-135b showed well differentiated tumors and acinar pattern while tumors in the control groups showed low differentiation and adenomatous pattern. Conclusions: Our data suggest that miR-135b is a key molecule whose activation is downstream of oncogenes and oncosuppressor genes frequently altered in CRC. Our study defines specific pathways that converge on the activation of the same microRNA. The “in vivo” silencing of miR-135 shows preclinical efficacy with low toxicity and represents the first in vivo study for the use of anti-miRs in CRC treatmen

CCAT2, a novel noncoding RNA mapping to 8q24, underlies metastatic progression and chromosomal instability in colon cancer

The functional roles of SNPs within the 8q24 gene desert in the cancer phenotype are not yet well understood. Here, we report that CCAT2, a novel long noncoding RNA transcript (lncRNA) encompassing the rs6983267 SNP, is highly overexpressed in microsatellite-stable colorectal cancer and promotes tumor growth, metastasis, and chromosomal instability. We demonstrate that MYC, miR-17-5p, and miR-20a are up-regulated by CCAT2 through TCF7L2-mediated transcriptional regulation. We further identify the physical interaction between CCAT2 and TCF7L2 resulting in an enhancement of WNT signaling activity. We show that CCAT2 is itself a WNT downstream target, which suggests the existence of a feedback loop. Finally, we demonstrate that the SNP status affects CCAT2 expression and the risk allele G produces more CCAT2 transcript. Our results support a new mechanism of MYC and WNT regulation by the novel lncRNA CCAT2 in colorectal cancer pathogenesis, and provide an alternative explanation of the SNP-conferred cancer risk

TLR3 essentially promotes protective class I–restricted memory CD8+ T-cell responses to Aspergillus fumigatus in hematopoietic transplanted patients

Aspergillus fumigatus is a model fungal pathogen and a common cause of severe infections and diseases. CD8+ T cells are present in the human and murine T-cell repertoire to the fungus. However, CD8+ T-cell function in infection and the molecular mechanisms that control their priming and differentiation into effector and memory cells in vivo remain elusive. In the present study, we report that both CD4+ and CD8+ T cells mediate protective memory responses to the fungus contingent on the nature of the fungal vaccine. Mechanistically, class I MHC-restricted, CD8+ memory T cells were activated through TLR3 sensing of fungal RNA by cross-presenting dendritic cells. Genetic deficiency of TLR3 was associated with susceptibility to aspergillosis and concomitant failure to activate memory-protective CD8+ T cells both in mice and in patients receiving stem-cell transplantations. Therefore, TLR3 essentially promotes antifungal memory CD8+ T-cell responses and its deficiency is a novel susceptibility factor for aspergillosis in high-risk patients.These studies were supported by the Specific Targeted Research Project ALLFUN (FP7-HEALTH-2009 contract number 260338 to L.R.), by SYBARIS (FP7-HEALTH-2009 contract number 242220 to L.R.), and by the Italian Project AIDS 2010 by the Istituto Superiore di Sanita (contract number 40H40 to L.R.). A.C. and C.C. were supported by fellowships from Fundacao para a Ciencia e Tecnologia, Portugal (contracts SFRH/BPD/46292/2008 and SFRH/BD/65962/2009, respectively)

Fcγ Receptor I Alpha Chain (CD64) Expression in Macrophages Is Critical for the Onset of Meningitis by Escherichia coli K1

Neonatal meningitis due to Escherichia coli K1 is a serious illness with unchanged morbidity and mortality rates for the last few decades. The lack of a comprehensive understanding of the mechanisms involved in the development of meningitis contributes to this poor outcome. Here, we demonstrate that depletion of macrophages in newborn mice renders the animals resistant to E. coli K1 induced meningitis. The entry of E. coli K1 into macrophages requires the interaction of outer membrane protein A (OmpA) of E. coli K1 with the alpha chain of Fcγ receptor I (FcγRIa, CD64) for which IgG opsonization is not necessary. Overexpression of full-length but not C-terminal truncated FcγRIa in COS-1 cells permits E. coli K1 to enter the cells. Moreover, OmpA binding to FcγRIa prevents the recruitment of the γ-chain and induces a different pattern of tyrosine phosphorylation of macrophage proteins compared to IgG2a induced phosphorylation. Of note, FcγRIa−/− mice are resistant to E. coli infection due to accelerated clearance of bacteria from circulation, which in turn was the result of increased expression of CR3 on macrophages. Reintroduction of human FcγRIa in mouse FcγRIa−/− macrophages in vitro increased bacterial survival by suppressing the expression of CR3. Adoptive transfer of wild type macrophages into FcγRIa−/− mice restored susceptibility to E. coli infection. Together, these results show that the interaction of FcγRI alpha chain with OmpA plays a key role in the development of neonatal meningitis by E. coli K1

Pathological and Molecular Features of Mucinous Colorectal Adenocarcinoma

Background: Mucinous carcinomas (MC) account for 10-15% of colorectal carcinomas (CRC) and are considered aggressive tumors.They differ from conventional adenocarcinoma for many clinico-pathologic and molecular characteristics with implications on patient management and prognosis. Aim of the study was to compare clinical, pathological and biologic features of MC (mucin >50%) with those of conventional adenocarcinomas (AD) and of adenocarcinomas with <50% of mucin (AD-MC). Design: The study included 1675 patients with CRC surgically resected between 2004 and 2018. Mismatch repair status (MMR) was determined in 1422 cases by immunohistochemical analysis of MLH1, MSH2, MSH6 and PMS2 expression and/or by microsatellite instability analysis using a fluorescent PCR method. Tumors with loss of MMR protein expression and/or MSI-H were classified as MMRdeficient (MMR-D) and tumors with retained MMR proteins expression and/or MSS/MSI-L as MMR-proficient (MMR-P). KRAS exon 2 and BRAF-V600E mutation were investigated by direct DNA sequencing or RT-PCR in 630 cases. Results: Of the 1675 tumors, 1123 (67%) were classified as AD, 352 (21%) as AD-MC and 200 (12%) as MC. Comparing the three groups, MC and AD-MC occurred more frequently in the proximal colon (p<0.001) and more often demonstrated poor differentiation. No other significative differences were found concerning the other clinical and pathological variables examined. MC (37%) and AD-MC (34%) were more frequently MMR-D (p<0.001) than AD (6%). MC (36%) and AD-MC (41%) were also more often BRAF mutated than AD (12%). KRAS mutations were detected at a higher rate in AD and MC with respect to AD-MC (p=0.01). As a whole the proportion of KRASwt/BRAFwt AD (45%) was higher with respect to AD-MC (22%) and MC (18%). The strong association between BRAF mutation and tumor type was also observed in the group of MMR-P carcinomas. Conclusions: MC represent a distinct but heterogeneous group of CRC, characterized by specific molecular features such as MMR deficit and BRAF mutation. Interestingly, AD-MC display a geneti

Medullary-type poorly differentiated adenocarcinoma of the large bowel: A distinct clinicopathologic entity characterized by microsatellite instability and improved survival

Purpose: Recent studies suggest the existence of a distinct class of poorly differentiated large bowel adenocarcinomas, usually termed medullary-type adenocarcinomas (MTAs). The aim of the present study was to accurately define the clinical, histopathologic, biologic, and genetic features of this tumor type. Materials and Methods: Among 1,265 surgically resected sporadic colorectal carcinomas, 45 MTAs were identified on the basis of the following criteria: predominantly solid growth pattern (at least 70% of the tumor area) and lack of marked nuclear pleomorphism. The clinicopathologic, biologic, and genetic characteristics of MTAs were compared with those of a series of 457 common glandular colorectal adenocarcinomas. Results: The significantly different clinicopathologic features of MTAs were proximal location, large size, invasion into adjacent organs, expanding pattern of growth, low incidence of distant metastases, more frequent conspicuous peritumoral lymphocytic infiltration, and Crohn’s-like lymphoid reaction. Furthermore, young patientswith MTAs often demonstrated a family history highly suggestive of a hereditary background. Unlike glandular adenocarcinomas, the large majority of MTAs were DNA diploid by flow cytometric analysis (21 of 25, 84%) and p53 negative by immunohistochemistry (36 of 41, 87.8%). In addition, 18 of the 20 MTAs examined by DNA microsatellite analysis demonstrated widespread microsatellite instability (90% of cases). Patients with MTAs showed a better clinical outcome with respect to patients with common poorly differentiated adenocarcinomas (PDAs) (P F .0001) and well- or moderately differentiated adenocarcinomas (WMDAs) (P 5 .133). In particular, none of the 33 patients with completely resectable stage II and III MTAs developed tumor recurrence during the observation period. Conversely, 24.7% of patients with stage II and III WMDAs and 48.9% of patients with stage II and III PDAs, who had undergone curative surgical resection, died of recurrent disease (P 5 .01 and P F.0001, respectively). Conclusion: All these data strongly indicate thatMTAs represent a distinct pathologic entity,with specific histologic appearance and peculiar clinical and genetic features. These tumors need to be classified separately from other poorly differentiated colorectal carcinomas

Analysis of MLH1 promoter methylation in colorectal carcinomas with microsatellite instability

Background Microsatellite analysis and immunohistochemistry for DNA mismatch repair proteins (MMRPs) demonstrated great utility in the identification of Lynch syndrome. However, the majority of MMR-deficient colorectal carcinomas are sporadic and produced by hypermethylation of the MLH1 promoter. The aim of our study was to evaluate the role of MLH1 promoter methylation analysis in the distinction between MLH1- negative sporadic and hereditary carcinomas. Methods The study included 370 colorectal adenocarcinomas. Microsatellite analysis was performed using the five markers of Bethesda plus BAT40 and a fluorescence based PCR method. MMRPs expression (MLH1, MSH2, MSH6, PMS2) was evaluated by immunohistochemistry. MLH1 promoter methylation (C-region, proximal relative to the transcription start of the MLH1 gene) was determined by methylation-specific PCR. Results MLH1 promoter methylation was detected in 198 of 272 (72.8%) MSI-H carcinomas, whereas all the 98 MSS/MSI-L tumors analyzed were unmethylated. Among MSI-H tumors, MLH1 methylation was found in 196/222 (88.3%) MLH1-negative carcinomas and in 2 of 50 (4%) MLH1-positive carcinomas (p<0.001). MLH1-negative tumors of patients aging <56 years were less frequently methylated (8/14, 57.1%) than tumors of patients aging 56–70 years (46/55, 83.6%) and of patients older than 70 years (142/153, 92.8%) (p<0.001). Conclusions Our data confirm that MLH1 promoter methylation is the major mechanism leading to MSI-H in colorectal cancer. Analysis of MLH1 methylation in conjunction with clinical data and MMRPs expression pattern may be relevant in the selection of patients with suspected Lynch syndrome for genetic testing