Novel ZC3H7B‐BCOR,MEAF6‐PHF1, and EPC1‐PHF1 fusions in ossifying fibromyxoid tumors—molecular characterization shows genetic overlap with endometrial stromal sarcoma

PHF1 gene rearrangements have been recently described in around 50% of ossifying fibromyxoid tumors (OFMT) including benign and malignant cases, with a small subset showing EP400‐PHF1 fusions. In the remaining cases no alternative gene fusions have been identified. PHF1‐negative OFMT, especially if lacking S100 protein staining or peripheral ossification, are difficult to diagnose and distinguish from other soft tissue mimics. In seeking more comprehensive molecular characterization, we investigated a large cohort of 39 OFMT of various anatomic sites, immunoprofiles and grades of malignancy. Tumors were screened for PHF1 and EP400 rearrangements by FISH. RNA sequencing was performed in two index cases (OFMT1, OFMT3), negative for EP400‐PHF1 fusions, followed by FusionSeq data analysis, a modular computational tool developed to discover gene fusions from paired‐end RNA‐seq data. Two novel fusions were identified ZC3H7B‐BCOR in OFMT1 and MEAF6‐PHF1 in OFMT3. After being validated by FISH and RT‐PCR, these abnormalities were screened on the remaining cases. With these additional gene fusions, 33/39 (85%) of OFMTs demonstrated recurrent gene rearrangements, which can be used as molecular markers in challenging cases. The most common abnormality is PHF1 gene rearrangement (80%), being present in benign, atypical and malignant lesions, with fusion to EP400 in 44% of cases. ZC3H7B‐BCOR and MEAF6‐PHF1 fusions occurred predominantly in S100 protein‐negative and malignant OFMT. As similar gene fusions were reported in endometrial stromal sarcomas, we screened for potential gene abnormalities in JAZF1 and EPC1 by FISH and found two additional cases with EPC1‐PHF1 fusions. © 2013 Wiley Periodicals, Inc.     

The characteristic expression of B7‐H3 and B7‐H4 in liver biopsies from patients with HBV‐related acute‐on‐chronic liver failure

Hepatitis B virus (HBV) is a major public health problem, and HBV‐related acute‐on‐chronic liver failure (HBV‐ACLF) has an extremely poor prognosis due to a lack of effective treatments. B7‐H3 and B7‐H4 are two novel members of the B7 superfamily that are actively involved in regulating the pathogenesis of infectious diseases. However, the intrahepatic expression of both members in HBV‐ACLF patients has yet to be described. In this study, we analyzed the expression of B7‐H3 and B7‐H4 in HBV‐ACLF biopsies by immunohistochemistry. Our results showed that both members were observed in all HBV‐ACLF samples, and their expression was chiefly observed on infiltrating inflammatory cells and the damaged bile ducts. Immunofluorescence double staining showed that B7‐H4 was expressed chiefly on CD3⁺ T cells, CD68⁺ macrophages, CK‐18⁺ bile ducts, and CD31⁺ endothelial cells, while B7‐H3 was found on all cell types detected. The expression of the programmed death (PD)‐1 ligands, PD‐L1 and PD‐L2, was also detected in these liver tissues and they were found to be co‐expressed with B7‐H3 and B7‐H4. These results suggest that the B7‐family signaling is most likely to affect the pathogenesis of this disease, and a clear understanding of their functional roles may further elucidate the disease process.     

B7‐H1 and CD8+ Treg: The enigmatic role of B7‐H1 in peripheral tolerance

The interaction between B7‐H1 (PD‐L1) expressed on APC with PD‐1 expressed by T cells was shown previously to result in inhibition of T‐cell activation and autoimmune diseases. A paper in this issue of the European Journal of Immunology demonstrates that DC B7‐H1 expression can in fact enhance autoimmunity, rather than suppress it. Using a model of direct injection of self antigen‐loaded DC into the CNS, the authors demonstrate that DC with intact B7‐H1 expression exacerbate CNS autoimmune disease. Importantly, the improved disease outcome in animals treated with B7‐H1^?/? DC is a result of a population of CD8⁺ Treg cells that expand at the site of autoimmune inflammation.     

Colonic low‐grade endometrial stromal sarcoma and orthotopic endometrial stromal tumor with limited infiltration sharing the JAZF1‐SUZ12 gene fusion

Endometrial stromal tumors (ESTs) are composed of cells resembling endometrial stroma, and are divided into benign and malignant types based on morphology. Endometrial stromal nodule (ESN) is a benign localized tumor, and endometrial stromal sarcoma (ESS) is an infiltrative and potentially metastatic neoplasm. A series of genetic aberrations contribute to pathological diagnosis of ESTs. At present, subsets of ESN and ESS‐low grade (ESS‐LG) are characterized as JAZF1‐SUZ12/JJAZ1 gene fusion. The ESTs that show higher grade atypia but lack nuclear pleomorphism include YWHAE‐FAM22 ESS. Here we report an unusual case of ESTs. Sudden colonic perforation occurred to the patient, and emergency surgery was performed. Pathological findings suggested metastatic ESS. Thorough medical examination of the genital organs detected a 1 cm‐sized well‐demarcated uterine tumor. Microscopically, the tumor lacked infiltrative features, conforming to the definition of ESN. Both lesions demonstrated identical cytology and shared JAZF1‐SUZ12 gene fusion. Endometriosis was not found in any areas of the resected organs, strongly suggesting that the uterine orthotopic tumor metastasized. The current case uncovered the problems of differential diagnosis between ESN and ESS‐LG. We demonstrate detailed pathological features of the two lesions, and discuss the possibility of orthotopic EST with limited infiltration to develop into ESS‐LG.     

Cytogenetic, molecular and testicular tissue studies in an infertile 45,X male carrying an unbalanced (Y;22) translocation: case report

(Y;autosome) translocations have been reported in association with male infertility. Different mechanisms have been suggested to explain the male infertility, such as deletion of the azoospermic factor (AZF) on the long arm of the Y chromosome, or meiosis impairment. We describe a new case with a de novo unbalanced translocation t(Y;22) and discuss the genotype-phenotype correlation. A 36 year old male with azoospermia was found to have a mosaic 45,X/46,X, + mar karyotype. Fluorescence in situ hybridization (FISH) showed the presence of a derivative Y chromosome containing the short arm, the centromere and a small proximal part of the long-arm euchromatin of the Y chromosome and the long arm of chromosome 22. The unstable small marker chromosome included the short arm and the centromere of chromosome 22. This unbalanced translocation t(Y;22)(q11.2;q11.1) generated the loss of the long arm of the Y chromosome involving a large part of AZFb, AZFc and Yq heterochromatin regions. Testicular tissue analyses showed sperm in the wet preparation. Our case shows the importance of documenting (Y;autosome) translocations with molecular and testicular tissue analyses.     

CD80 (B7‐1) and CD86 (B7‐2) genes and genetic susceptibility to coeliac disease

The role of the costimulatory molecules B7‐1 (CD80) and B7‐2 (CD86) in T‐cell activation makes them good candidates for coeliac disease susceptibility genes. We conducted a genetic linkage study of the CD80/86 gene region in the general Finnish population and in a local subisolate. No linkage was found in either population.     

Features of Turner''s and DiGeorge''s syndromes in a child with an X;22 translocation.

We describe the clinical and cytogenetic findings in an infant who presented with the features of both Turner's and DiGeorge's syndromes associated with a unique translocation between chromosomes X and 22.     

Establishment and characterization of a MALT lymphoma cell line carrying an API2‐MALT1 translocation

MALT lymphomas with API2(BIRC3)‐MALT1 translocation usually have an indolent clinical course and rarely transform into aggressive lymphoma, and there have been no lymphoma cell lines carrying API2‐MALT1 translocation reported to date. We established a novel lymphoma cell line named BMA19, carrying the API2‐MALT1 translocation from a patient with histologic transformation of intestinal MALT lymphoma. The cells were suggested to carry API2‐MALT1 and MYC‐IGH translocations by chromosomal analysis, and these translocations were confirmed by polymerase chain reaction analysis. The expression of MYC was shown to be enhanced as a result of the MYC‐IGH translocation, and it is considered to have played a role in the histologic transformation of MALT lymphoma. Whole exome sequencing of BMA19 identified several nucleotide variations in genes reported to be mutated in previous studies of marginal zone lymphomas. The MALT1 inhibitor MI‐2 specifically decreased cell growth, and the BMA19 cell line was suggested to be still dependent on the API2‐MALT1 signal. Subtractive microarray analysis showed that one of the earliest events resulting from MALT1 inhibition is increased susceptibility to endoplasmic reticulum stress‐induced apoptosis. The BMA19 cell line is considered to conserve the biological properties of MALT lymphoma and is expected to be a valuable tool for research into the pathogenesis of MALT lymphoma with an API2‐MALT1 translocation.     

Human mesenchymal stromal cells modulate T‐cell responses through TNF‐α‐mediated activation of NF‐κB

Although mesenchymal stromal cells (MSCs) possess the capacity to modulate immune responses, little is known about the mechanisms that underpin these processes. In this study, we show that immunosupression is mediated by activation of nuclear factor kappa B (NF‐κB) in human MSCs. This pathway is activated by TNF‐α that is generated following TCR stimulation of T cells. Inhibition of NF‐κB through silencing of IκB kinase β or the TNF‐α receptor abolishes the immunosuppressive capacity of MSCs. Our data also indicate that MSC‐associated NF‐κB activation primarily leads to inhibition of T‐cell proliferation with little effect on expression of the activation markers CD69 and CD25. Thus, our data support the hypothesis that the TNF‐α/NF‐κB signalling pathway is required for the initial priming of immunosuppressive function in human MSCs. Interestingly, drugs that interfere with NF‐κB activation significantly antagonise the immunoregulatory effect of MSCs, which could have important implications for immunosuppression regimens in the clinic.     

L-22 enhances the invasiveness of endometrial stromal cells of adenomyosis in an autocrine manner

It has reported that interleukin-22 (IL-22) promotes the invasion of tumor cells. IL-22 in the endometriotic milieu stimulates the proliferation of human endometrial stromal cells (ESCs). The present study aimed to elucidate whether and how IL-22 regulates the invasion of ESCs from adenomyosis. The expression of IL-22 and its receptors in normal endometrium, eutopic endometrium and ectopic lesion was analyzed by immunohistochemistry; the invasiveness of ESCs in vitro was verified by Matrigel invasion assay; and the effects of IL-22 on the correspondent functional molecules were investigated by ELISA and flow cytometry. Here we found that IL-22 and its receptors IL-22R1 and IL-10R2 in eutopic endometrium and ectopic lesion of adenomyosis were significantly higher than that of normal endometrium. Recombinant human IL-22 (rhIL-22) increased IL-22R1 and IL-10R2 levels on ESCs. Moreover, rhIL-22 promoted the invasiveness of ESCs, and inhibited the expression of metastasis suppressor gene CD82, stimulated the secretion of IL-8, RANTES, IL-6 and VEGF of ESCs. On the contrary, the neutralizing antibody for IL-22 reversed these effects. Our current study has demonstrated that IL-22 has a positive feedback on the expression of its receptors IL-22R1 and IL-10R2 on ESCs. This autocrine effect of IL-22 promotes the invasion of ESCs possibly through regulating invasion-related molecules, suggesting that the abnormal high expression of IL-22 may play an important role in ESCs invasion and finally contribute to the origin and development of adenomyosis.     

MiR‐1253 exerts tumor‐suppressive effects in medulloblastoma via inhibition of CDK6 and CD276 (B7‐H3)

Of the four primary subgroups of medulloblastoma, the most frequent cytogenetic abnormality, i17q, distinguishes Groups 3 and 4 which carry the highest mortality; haploinsufficiency of 17p13.3 is a marker for particularly poor prognosis. At the terminal end of this locus lies miR‐1253, a brain‐enriched microRNA that regulates bone morphogenic proteins during cerebellar development. We hypothesized miR‐1253 confers novel tumor‐suppressive properties in medulloblastoma. Using two different cohorts of medulloblastoma samples, we first studied the expression and methylation profiles of miR‐1253. We then explored the anti‐tumorigenic properties of miR‐1253, in parallel with a biochemical analysis of apoptosis and proliferation, and isolated oncogenic targets using high‐throughput screening. Deregulation of miR‐1253 expression was noted, both in medulloblastoma clinical samples and cell lines, by epigenetic silencing via hypermethylation; specific de‐methylation of miR‐1253 not only resulted in rapid recovery of expression but also a sharp decline in tumor cell proliferation and target gene expression. Expression restoration also led to a reduction in tumor cell virulence, concomitant with activation of apoptotic pathways, cell cycle arrest and reduction of markers of proliferation. We identified two oncogenic targets of miR‐1253, CDK6 and CD276, whose silencing replicated the negative trophic effects of miR‐1253. These data reveal novel tumor‐suppressive properties for miR‐1253, i.e., (i) loss of expression via epigenetic silencing; (ii) negative trophic effects on tumor aggressiveness; and (iii) downregulation of oncogenic targets.     

Chitin induces upregulation of B7‐H1 on macrophages and inhibits T‐cell proliferation

Chitin is a highly abundant glycopolymer, which serves as structural component in fungi, arthropods and crustaceans but is not synthesized by vertebrates. However, vertebrates express chitinases and chitinase‐like proteins, some of which are induced by infection with helminths suggesting that chitinous structures may be targets of the immune system. The chitin‐induced modulations of the innate and adaptive immune responses are not well understood. Here, we demonstrate that intranasal administration of OVA and chitin resulted in diminished T‐cell expansion and Th2 polarization as compared with OVA administration alone. Chitin did not promote nor attenuate Th2 polarization in vitro. Chitin‐exposed macrophages inhibited proliferation of CD4⁺ T cells in a cell–cell contact‐dependent manner. Chitin induced upregulation of the inhibitory ligand B7‐H1 (PD‐L1) on macrophages independently of MyD88, TRIF, TLR2, TLR3, TLR4 and Stat6. Inhibition of T‐cell proliferation was largely dependent on B7‐H1, as the effect was not observed in cocultures with cells from B7‐H1‐deficient mice.