Clostridium sordellii is an emerging pathogen associated with highly lethal female reproductive tract infections following childbirth, abortion, or cervical instrumentation. Gaps in our understanding ...of the pathogenesis of C. sordellii infections present major challenges to the development of better preventive and therapeutic strategies against this problem. We sought to determine the mechanisms whereby uterine decidual macrophages phagocytose this bacterium and tested the hypothesis that human decidual macrophages use class A scavenger receptors to internalize unopsonized C. sordellii. In vitro phagocytosis assays with human decidual macrophages incubated with pharmacological inhibitors of class A scavenger receptors (fucoidan, polyinosinic acid, and dextran sulfate) revealed a role for these receptors in C. sordellii phagocytosis. Soluble macrophage receptor with collagenous structure (MARCO) receptor prevented C. sordellii internalization, suggesting that MARCO is an important class A scavenger receptor in decidual macrophage phagocytosis of this microbe. Peritoneal macrophages from MARCO-deficient mice, but not wild-type or scavenger receptor AI/II-deficient mice, showed impaired C. sordellii phagocytosis. MARCO-null mice were more susceptible to death from C. sordellii uterine infection than wild-type mice and exhibited impaired clearance of this bacterium from the infected uterus. Thus, MARCO is an important phagocytic receptor used by human and mouse macrophages to clear C. sordellii from the infected uterus.
Objectives
Although commonly associated with high‐grade myelodysplastic syndrome (MDS) and MDS with a complex karyotype, TP53 mutations also occur in low‐grade MDS and MDS with a non‐complex ...karyotype. In latter cases, their clinicopathological features and the characteristics of TP53 mutations remain poorly characterized.
Methods
176 MDS cases with TP53 mutations were stratified and characterized based on their karyotype and histologic subtype.
Results
Among 176 cases, 17% had a non‐complex karyotype and 24% were low‐grade MDS. TP53 mutations often occurred in DNA‐binding domains and the majority of cases had only one mutation, irrespective of their karyotype and MDS subtype. The variant allele frequency (VAF), however, was associated with karyotype complexity and the types of MDS with a lower VAF found in cases with a non‐complex karyotype and low‐grade MDS. A low (<20%) VAF was associated with a better survival, as well as low‐grade subtype.
Conclusions
In low‐grade MDS and MDS with a non‐complex karyotype, TP53 mutations showed a lower VAF. Patients with a lower VAF had a better survival. TP53 mutations are not the only prognostic factor in MDS patients with TP53 mutations as the VAF, blast counts and history of prior therapy also play important roles in prognosis.
Fluorescence in situ hybridization (FISH) is a confirmatory test to establish a diagnosis of inv(16)/t(16;16) AML. However, incidental findings and their clinical diagnostic implication have not been ...systemically studied. We studied 1629 CBFB FISH cases performed in our institution, 262 (16.1%), 1234 (75.7%), and 133 (8.2%) were reported as positive, normal, and abnormal, respectively. The last included
copy number changes (
= 120) and atypical findings such as 3'CBFB deletion (
= 11), 5'CBFB deletion (
= 1), and 5'
gain (
= 1). Correlating with
RT-PCR results, totally 271
rearrangement cases were identified, including five with discrepancies between FISH and RT-PCR due to new partner genes (
= 3), insertion (
= 1), or rare
variant (
= 1) and eight with
deletion. All cases with atypical findings and/or discrepancies presented clinical diagnostic challenges. Correlating FISH signal patterns and karyotypes, additional chromosome 16 aberrations (AC16As) show impacts on the re-definition of a complex karyotype and prognostic prediction. The
rearrangement but not all AC16As will be detected by NGS-based methods. Therefore, FISH testing is currently still needed to provide a quick and straightforward confirmatory inv(16)/t(16;16) AML diagnosis and additional information related to clinical management.
Dysregulated NF-κB signaling is critical for lymphomagenesis. The regulation, function, and clinical relevance of c-Rel/NF-κB activation in diffuse large B-cell lymphoma (DLBCL) have not been well ...studied. In this study we analyzed the prognostic significance and gene-expression signature of c-Rel nuclear expression as surrogate of c-Rel activation in 460 patients with de novo DLBCL. Nuclear c-Rel expression, observed in 137 (26.3%) DLBCL patients frequently associated with extranoal origin, did not show significantly prognostic impact in the overall- or germinal center B-like-DLBCL cohort, likely due to decreased pAKT and Myc levels, up-regulation of FOXP3, FOXO3, MEG3 and other tumor suppressors coincided with c-Rel nuclear expression, as well as the complicated relationships between NF-κB members and their overlapping function. However, c-Rel nuclear expression correlated with significantly poorer survival in p63+ and BCL-2- activated B-cell-like-DLBCL, and in DLBCL patients with TP53 mutations. Multivariate analysis indicated that after adjusting clinical parameters, c-Rel positivity was a significantly adverse prognostic factor in DLBCL patients with wild type TP53. Gene expression profiling suggested dysregulations of cell cycle, metabolism, adhesion, and migration associated with c-Rel activation. In contrast, REL amplification did not correlate with c-Rel nuclear expression and patient survival, likely due to co-amplification of genes that negatively regulate NF-κB activation. These insights into the expression, prognostic impact, regulation and function of c-Rel as well as its crosstalk with the p53 pathway underscore the importance of c-Rel and have significant therapeutic implications.
Reduced Paired box 5 (PAX5) levels have important roles in the pathogenesis of human B-cell acute lymphoblastic leukemia. However, the role of PAX5 in human lymphoma remains unclear. We generated ...PAX5-silenced cells using mantle cell lymphoma (MCL) as a model system. These PAX5(-) MCL cells exhibited unexpected phenotypes, including increased proliferation in vitro, enhanced tumor infiltration in vivo, robust adhesion to the bone marrow stromal cells and increased retention of quiescent stem-like cells. These phenotypes were attributed to alterations in the expression of genes including p53 and Rb, and to phosphoinositide 3-kinase/mammalian target of rapamycin and phosphorylated signal transducer and activator of transcription 3 pathway hyperactivation. On PAX5 silencing, the MCL cells displayed upregulated interleukin (IL)-6 expression and increased responses to paracrine IL-6. Moreover, decreased PAX5 levels in CD19+ MCL cells correlated with their increased infiltration and progression; thus, PAX5 levels can be used as a prognostic marker independent of cyclin D1 in advanced MCL patients. Importantly, high-throughput screening of 3800 chemical compounds revealed that PAX5(-) MCL cells are highly drug-resistant compared with PAX5 wild-type MCL cells. Collectively, the results of our study support a paradigm shift regarding the functions of PAX5 in human B-cell cancer and encourage future efforts to design effective therapies against MCL.
In a subset of acute myeloid leukemia (AML) cases, the core binding factor beta subunit gene (CBFB) was rearranged via inv(16)(p13.1q22) or t(16;16)(p13.1;q22), in which the smooth muscle myosin ...heavy chain 11 gene (MYH11) was the partner (CBFB::MYH11). Rare variants of CBFB rearrangement occurring via non-classic chromosomal aberrations have been reported, such as t(1;16), t(2;16), t(3;16), t(5;16), and t(16;19), but the partners of CBFB have not been characterized. We report a case of AML with a complex karyotype, including t(2;16)(q37;q22), in which the protein phosphatase 1 regulatory subunit 7 gene (PPP1R7) at chromosome 2q37 was rearranged with CBFB (CBFB::PPP1R7). This abnormality was inconspicuous by conventional karyotype and interphase fluorescence in situ hybridization (FISH), thus leading to an initial interpretation of inv(16)(p13.1q22); however, metaphase FISH showed that the CBFB rearrangement involved chromosome 2. Using whole genome and Sanger sequencing, the breakpoints were identified as being located in intron 5 of CBFB and intron 7 of PPP1R7. A microhomology of CAG was found in the break and reconnection sites of CBFB and PPP1R7, thus supporting the formation of CBFB::PPP1R7 by microhomology-mediated end joining.
Summary A few recent studies investigated the prognostic impact of CD30 expression in diffuse large B cell lymphoma (DLBCL) patients treated with rituximab, cyclophosphamide, doxorubicin, ...vincristine, and prednisone. No study has evaluated the significance of CD30 expression in DLBCL patients treated with rituximab, etoposide, prednisone, vincristine, cyclophosphamide, and doxorubicin (R-EPOCH). In a group of 97 patients with DLBCL and high-risk features who received R-EPOCH induction therapy, we studied CD30 expression by immunohistochemistry using different cutoff values (> 0% and ≥20% of lymphoma cells, respectively) and correlated with prognosis. CD30 expression was detected in 24 (25%) cases using a cutoff of >0% and in 12 (12%) cases using a cutoff of ≥20%. The clinicopathologic features were similar between CD30+ and CD30-negative groups. A major difference was that MYC rearrangement was infrequent in the CD30+ group: 2/23 (9%) in CD30+ versus 25/72 (35%) in CD30-negative group (P = .02). CD30 expression was not associated with germinal center B-cell-like (GCB) or non-GCB type. Overall survival (OS) was not significantly different between patients with CD30+ versus CD30-negative DLBCL, either for all patients or the subset of patients without MYC rearrangement, regardless of cutoff (P > .05). CD30 expression was not associated with OS in either GCB or non-GCB subtype (P > .05, > 0% cutoff). In conclusion, CD30 expression was detected in up to 25% of cases of DLBCL and was more frequent in tumors without MYC rearrangement. CD30 expression was not associated with OS in R-EPOCH treated de novo DLBCL patients.
Lymphoblastic leukemia (ALL) following myelodysplastic syndrome (MDS) or myelodysplastic/myeloproliferative neoplasm (MDS/MPN) is very rare. We report five cases: four had ALL diagnosed after MDS or ...MDS/MPN and one had ALL and MDS diagnosed simultaneously. At the onset of ALL, all patients showed co-existing MDS or MDS/MPN. Map-back FISH was performed in four patients, showing that ALL and MDS were cytogenetically related in two patients and unrelated in the other two patients. All five patients were treated with ALL-based chemotherapies, two patients with ALL clonally related to MDS were refractory to the therapies, whereas the other three patients achieved remission. We conclude that ALL developed after MDS is extremely rare. In some patients, ALL is clonally related to MDS and these patients may be refractory to ALL-based chemotherapies. In other patients who have no evidence of clonal relation between ALL and MDS, these patients more likely respond to ALL-based treatment regimens.
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