Monosomy 7 and del(7q) are associated with adverse features in myeloid malignancies. A 2.5-Mb commonly deleted segment (CDS) of chromosome band 7q22 is implicated as harboring a myeloid tumor suppressor gene (TSG); however, molecular analysis of candidate TSGs has not uncovered loss of function. To determine whether haploinsufficiency for the 7q22 CDS contributes to myeloid leukemogenesis, we performed sequential gene targeting to flank a region of orthologous synteny on mouse chromosome band 5A3 with loxP sites. We then generated Mx1-Cre, 5A3 fl mutant mice and deleted the targeted interval in vivo. Although excision was inefficient, we confirmed somatic deletion of the 5A3 CDS in the hematopoietic stem cell compartment. Mx1-Cre, 5A3 fl mice show normal hematologic parameters and do not spontaneously develop myeloid malignancies. The 5A3 fl deletion does not cooperate with oncogenic Kras G12D expression, Nf1 inactivation, or retroviral mutagenesis to accelerate leukemia development and did not modulate responsiveness to antileukemia drugs. These studies demonstrate that it is feasible to somatically delete a large chromosomal segment implicated in tumor suppression in hematopoietic cell populations in vivo; however, our data do not support the hypothesis that the 7q22/5A3 CDS interval contains a myeloid TSG. IntroductionLoss of chromosome 7 and deletion of a segment of the long arm (monosomy 7 and del(7q)) are recurring cytogenetic abnormalities in de novo and therapy-induced myeloid malignancies that are associated with advanced age, antecedent myelodysplastic syndrome (MDS), and resistance to current treatments. 1 Based on precedents in other cancers, it is likely that loss of one or more 7q tumor suppressor genes (TSGs) contributes to leukemogenesis. To facilitate the identification of candidate myeloid TSGs, Le Beau et al delineated 2 commonly deleted segments (CDSs) in patients with myeloid disorders characterized by a del(7q), a proximal interval within band q22 that accounts for most cases, and a second CDS in bands q32-34. 2 Using an ordered set of yeast artificial chromosome clones as probes, these investigators then performed fluorescence in situ hybridization (FISH) experiments to further characterize leukemias with deletion breakpoints within 7q22 and implicated an approximately 2.5-Mb CDS as harboring a myeloid TSG. We and others have extensively characterized this CDS, identified and cloned multiple genes from the interval, analyzed leukemia samples for mutations in these candidate TSGs, and performed Taqman real-time quantitative reverse-transcriptase polymerase chain reaction (RT-PCR) assays to measure expression levels in normal and leukemic human bone marrows. [3][4][5][6] These studies did not uncover biallelic inactivation or epigenetic silencing of any candidate TSGs located within this CDS. [3][4][5] Thus, it was hypothesized that inactivation of a single allele (haploinsufficiency) of one or more TSGs located within the 2.5-Mb CDS might contribute to leukemogenesis. 4,5 Recent technical ...
Neuromyelitis optica is an autoimmune disease characterized by acute episodes of transverse myelitis and optic neuritis. Several small, open-label studies suggest rituximab, a monoclonal antibody against CD20, prevents relapses in neuromyelitis optica; however, there is little consensus on timing or duration of treatment. Here we report four patients with severe relapsing neuromyelitis optica who were stabilized on rituximab and, after discontinuing treatment, continued to experience prolonged remission of their disease. Remission ranged from 4.5 to 10.5 years total, including 3 to 9 years off all therapies. The patients had sustained clinical responses despite normal B-lymphocyte levels and, in at least 2 patients, continued seropositivity for aquaporin-4 antibodies. These cases suggest that rituximab may induce prolonged remission in certain neuromyelitis optica patients, and they highlight the need for further elucidation of rituximab's mechanism in neuromyelitis optica.
Chromosome 7 deletions are highly prevalent in myelodysplastic syndrome (MDS) and likely contribute to aberrant growth through haploinsufficiency. We generated mice with a heterozygous germ line deletion of a 2-Mb interval of chromosome band 5A3 syntenic to a commonly deleted segment of human 7q22 and show that mutant hematopoietic cells exhibit cardinal features of MDS. Specifically, the long-term hematopoietic stem cell (HSC) compartment is expanded in 5A3+/del mice, and the distribution of myeloid progenitors is altered. 5A3+/del HSCs are defective for lymphoid repopulating potential and show a myeloid lineage output bias. These cell autonomous abnormalities are exacerbated by physiologic aging and upon serial transplantation. The 5A3 deletion partially rescues defective repopulation in Gata2 mutant mice. 5A3+/del hematopoietic cells exhibit decreased expression of oxidative phosphorylation genes, increased levels of reactive oxygen species, and perturbed oxygen consumption. These studies provide the first functional data linking 7q22 deletions to MDS pathogenesis.DOI: http://dx.doi.org/10.7554/eLife.07839.001
Exposure to other young children may be an early protective factor against the development of NMO, as previously reported for MS, consistent with the hypothesis that infections contribute to disease risk modification. Unlike MS, pediatric NMO does not appear to be associated with exposures to common herpes viruses.
In the era of precision medicine, biopsies are playing an increasingly central role in cancer research and treatment paradigms; however, patient outcomes and analyses of biopsy quality, as well as impact on downstream clinical and research applications, remain underreported. Herein, we report biopsy safety and quality outcomes for percutaneous core biopsies of hepatocellular carcinoma (HCC) performed as part of a prospective clinical trial. Patients with a clinical diagnosis of HCC were enrolled in a prospective cohort study for the genetic, proteomic, and metabolomic profiling of HCC at two academic medical centers from April 2016 to July 2020. Under image guidance, 18G core biopsies were obtained using coaxial technique at the time of locoregional therapy. The primary outcome was biopsy quality, defined as tumor fraction in the core biopsy. 56 HCC lesions from 50 patients underwent 60 biopsy events with a median of 8 core biopsies per procedure (interquartile range, IQR, 7–10). Malignancy was identified in 45/56 (80.4%, 4 without pathology) biopsy events, including HCC (40/56, 71.4%) and cholangiocarcinoma (CCA) or combined HCC-CCA (5/56, 8.9%). Biopsy quality was highly variable with a median of 40% tumor in each biopsy core (IQR 10–75). Only 43/56 (76.8%) and 23/56 (41.1%) samples met quality thresholds for genomic or metabolomic/proteomic profiling, respectively, requiring expansion of the clinical trial. Overall and major complication rates were 5/60 (8.3%) and 3/60 (5.0%), respectively. Despite uniform biopsy protocol, biopsy quality varied widely with up to 59% of samples to be inadequate for intended purpose. This finding has important consequences for clinical trial design and highlights the need for quality control prior to applications in which the presence of benign cell types may substantially alter findings.
Background. Nonalcoholic fatty liver disease (NAFLD) is a leading cause of hepatocellular carcinoma (HCC) in the United States. Prior data suggest that NAFLD-HCC patients are less likely to receive liver transplantation (LT) and have worse overall survival; however, the reason for this discrepancy is unknown. Methods. We conducted a retrospective study of 631 HCC patients listed for LT at a large academic center from 2004 to 2013. Waitlist dropout and LT were analyzed using competing risk regression. Results. Compared with other-HCC patients (n = 589), NAFLD-HCC patients (n = 42, 6.7%) were older (65 versus 58, P < 0.001) with more women (50.0 versus 23.6%, P < 0.001), Hispanic ethnicity (40.5 versus 17.7%, P = 0.001), obesity (69.0 versus 29.9%, P < 0.001), diabetes mellitus (59.5 versus 27.8%, P < 0.01), insulin-dependence (23.8 versus 10.2%, P = 0.007), hyperlipidemia (40.5 versus 10.5, P < 0.001), and statin use (33.3 versus 5.3%, P < 0.001). Cumulative incidence of waitlist dropout at 2 y was 17.4% (95% confidence intervals, 7.7-30.4) for NAFLD HCC and 25.4% (95% confidence intervals, 21.9-29.0) for other HCC (P = 0.28). No difference in waitlist dropout or receipt of LT between NAFLD HCC and other HCC was found on regression analysis. Similarly, NAFLD and obesity, obesity alone, diabetes mellitus, insulin-dependence, hyperlipidemia, and statin use were not associated with waitlist outcomes. Finally, we observed no statistically significant difference in 5-y survival from HCC diagnosis between NAFLD HCC and other HCC (78.5% versus 66.9%, P = 0.9). Conclusions. In our single-center cohort, we observed no difference in waitlist outcomes or survival in NAFLD HCC, although conclusions are limited by the small number of NAFLD-HCC patients. Notably, the inclusion of patients with obesity in the NAFLD-HCC group and stratification by individual metabolic factors also showed no difference in waitlist outcomes.
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