An arrayed genome-wide perturbation screen identifies the ribonucleoprotein Hnrnpk as rate-limiting for prion propagation.

A defining characteristic of mammalian prions is their capacity for self-sustained propagation. Theoretical considerations and experimental evidence suggest that prion propagation is modulated by cell-autonomous and non-autonomous modifiers. Using a novel quantitative phospholipase protection assay (QUIPPER) for high-throughput prion measurements, we performed an arrayed genome-wide RNA interference (RNAi) screen aimed at detecting cellular host-factors that can modify prion propagation. We exposed prion-infected cells in high-density microplates to 35,364 ternary pools of 52,746 siRNAs targeting 17,582 genes representing the majority of the mouse protein-coding transcriptome. We identified 1,191 modulators of prion propagation. While 1,151 modified the expression of both the pathological prion protein, PrPSc , and its cellular counterpart, PrPC , 40 genes selectively affected PrPSc . Of the latter 40 genes, 20 augmented prion production when suppressed. A prominent limiter of prion propagation was the heterogeneous nuclear ribonucleoprotein Hnrnpk. Psammaplysene A (PSA), which binds Hnrnpk, reduced prion levels in cultured cells and protected them from cytotoxicity. PSA also reduced prion levels in infected cerebellar organotypic slices and alleviated locomotor deficits in prion-infected Drosophila melanogaster expressing ovine PrPC . Hence, genome-wide QUIPPER-based perturbations can discover actionable cellular pathways involved in prion propagation. Further, the unexpected identification of a prion-controlling ribonucleoprotein suggests a role for RNA in the generation of infectious prions.

YTGT: A new high-prevalence antigen in the Yt blood group system in two unrelated Native Americans and transfusion management.

BACKGROUND: The Yt system consists of five antigens: antithetical Yta /Ytb and the high-prevalence antigens YTEG, YTLI, and YTOT. We investigated a sample from a Native American (NA) female with post-operative anemia and an unidentified antibody who developed rigors, tachycardia, and hypotension on transfusion of incompatible RBCs. METHODS AND MATERIALS: Serologic testing methods included LISS, PEG, and IgG gel. Test RBCs were treated with papain, trypsin, alpha-chymotrypsin, 2-amino-ethylisothiouronium, and dithiothreitol. Rare RBCs were tested, and inhibition studies were performed. DNA extracted from WBCs was used for Sanger sequencing. RESULTS: Initial testing showed strong 3-4+ plasma reactivity with all panel cells at LISS IAT; auto control was negative. Positive reactions were observed with numerous rare RBCs except for PNH-III, which lack GPI-linked DO, Yt, CROM, JMH, and Emm. Enzyme sensitivity patterns suggest Yt specificity, and soluble recombinant srYt neutralized reactivity. ACHE sequencing revealed YT*A/A genotype but with a homozygous change in exon 2, c.290A>G (p.Gln97Arg). Antibody reactivity was reminiscent of that seen in an unrelated NA male investigated previously. His RBCs were nonreactive with her plasma. ACHE carried the same c.290G/G change. CONCLUSION: Two unrelated NA patients were found to have an antibody to a new high-prevalence Yt antigen, designated YTGT (YT6), associated with a clinically significant transfusion reaction. Identification of the specificity relied on enzyme sensitivity, use of PNH-III RBCs, neutralization using soluble recombinant Yt, and the finding of a novel change in ACHE, c.290A>G (p.Gln97Arg), designated YT*01.-06. IVIG and steroids were used to mitigate further reactions to transfusion.

Novel regulators of PrPC biosynthesis revealed by genome-wide RNA interference.

The cellular prion protein PrPC is necessary for prion replication, and its reduction greatly increases life expectancy in animal models of prion infection. Hence the factors controlling the levels of PrPC may represent therapeutic targets against human prion diseases. Here we performed an arrayed whole-transcriptome RNA interference screen to identify modulators of PrPC expression. We cultured human U251-MG glioblastoma cells in the presence of 64'752 unique siRNAs targeting 21'584 annotated human genes, and measured PrPC using a one-pot fluorescence-resonance energy transfer immunoassay in 51'128 individual microplate wells. This screen yielded 743 candidate regulators of PrPC. When downregulated, 563 of these candidates reduced and 180 enhanced PrPC expression. Recursive candidate attrition through multiple secondary screens yielded 54 novel regulators of PrPC, 9 of which were confirmed by CRISPR interference as robust regulators of PrPC biosynthesis and degradation. The phenotypes of 6 of the 9 candidates were inverted in response to transcriptional activation using CRISPRa. The RNA-binding post-transcriptional repressor Pumilio-1 was identified as a potent limiter of PrPC expression through the degradation of PRNP mRNA. Because of its hypothesis-free design, this comprehensive genetic-perturbation screen delivers an unbiased landscape of the genes regulating PrPC levels in cells, most of which were unanticipated, and some of which may be amenable to pharmacological targeting in the context of antiprion therapies.

Blood and Marrow Transplant Clinical Trials Network Study 1102 heralds a new era in hematopoietic cell transplantation in high-risk myelodysplastic syndromes: Challenges and opportunities in implementation.

LAY SUMMARY: People who have advanced myelodysplastic syndromes (MDS) may live longer if they get a bone marrow transplant (BMT) instead of other therapies. However, only 15% of people with MDS actually get BMT. Experts say community physicians and transplant physicians should team up with insurance companies and patient advocacy groups to 1) spread this news about lifesaving advances in BMT, 2) ensure that everyone can afford health care, 3) provide emotional support for patients and families, 4) help patients and families get transportation and housing if they need to travel for transplant, and 5) improve care for people of under-represented racial and ethnic backgrounds.

Real-World Outcomes and Clinical Predictors of Immune Checkpoint Inhibitor Monotherapy in Advanced Lung Cancer.

BACKGROUND: Immune checkpoint inhibitors (ICIs) have changed the treatment paradigm of advanced-stage non-small-cell lung cancer (NSCLC) and small-cell lung cancer (SCLC). The aim of this study was to evaluate the effectiveness and tolerance of ICIs in a real-world patient population and to investigate the predictive factors associated with survival outcomes. METHODS: Medical records of patients with advanced lung cancer who started ICI monotherapy were reviewed for data collection. Treatment outcomes included objective response rate, progression-free survival (PFS), and overall survival (OS). Immune-related adverse events (irAEs) were assessed. Multiple Cox regression models were fit to investigate the predictive factors for survival outcomes. RESULTS: We included 220 patients (median 66.5 years). Seventy-nine (35.9%) patients had Eastern Cooperative Oncology Group (ECOG) performance-status (PS) score ⩾2. Median follow-up was 11.4 months. In NSCLC, median PFS was 3.8 months (4.7 months for first line and 3.7 months for subsequent line). Median OS was 12.4 months (15.6 months for first line therapy and 11.5 months for subsequent line). In SCLC, median PFS was 1.8 months, and median OS was 4.6 months. A quarter of patients developed irAEs. There was 1 disease flare among 17 patients with pre-existing autoimmune diseases. ECOG PS of 0 to 1 and body mass index (BMI) ⩾ 25 kg/m2 (but not occurrence of irAE) were independently associated with improved OS in NSCLC, with a hazard ratio of 0.41 (95% confidence interval [CI], 0.29-0.59) and 0.62 (95% CI, 0.44-0.87), respectively. CONCLUSIONS: The clinical benefit of ICIs appears to persist in a real-world population of relatively older age, including those with poor PS and pre-existing autoimmune diseases. ECOG PS of 0 to 1 and BMI ⩾ 25 kg/m2 were independently associated with improved OS.

An integrated genomic approach to dissect the genetic landscape regulating the cell-to-cell transfer of α-synuclein.

Neuropathological and experimental evidence suggests that the cell-to-cell transfer of α-synuclein has an important role in the pathogenesis of Parkinson's disease (PD). However, the mechanism underlying this phenomenon is not fully understood. We undertook a small interfering RNA (siRNA), genome-wide screen to identify genes regulating the cell-to-cell transfer of α-synuclein. A genetically encoded reporter, GFP-2A-αSynuclein-RFP, suitable for separating donor and recipient cells, was transiently transfected into HEK cells stably overexpressing α-synuclein. We find that 38 genes regulate the transfer of α-synuclein-RFP, one of which is ITGA8, a candidate gene identified through a recent PD genome-wide association study (GWAS). Weighted gene co-expression network analysis (WGCNA) and weighted protein-protein network interaction analysis (WPPNIA) show that those hits cluster in networks that include known PD genes more frequently than expected by random chance. The findings expand our understanding of the mechanism of α-synuclein spread.

A medicare database analysis of practice patterns in patients with mantle cell lymphoma.

INTRODUCTION: Although treatment approaches to younger fit patients with mantle cell lymphoma (MCL) are well-described, the optimal treatment of older or less fit patients with varying comorbidities is less clear. The objectives of this study were to examine first-line treatment patterns, and the impact of comorbidities and age on treatment choices and overall survival (OS) in a large, predominantly older, Medicare population. PATIENTS AND METHODS: In Medicare data from 1/1/2007-8/31/2015, 3,008 patients with MCL were identified. Data on age, gender, race, Charlson comorbidities, Charlson comorbidity index (CCI), timing of injectable MCL therapies, and OS were collected and analyzed. RESULTS: Median age of the study population was 75.5 (range, 33-107; 25th, 75th: 69.9, 81.5) years. Over half of the individuals had ≥two comorbidities. The CCI was 1-2 in 45%, and 3-4 in 26.6% of patients. Rituximab was the most commonly used agent, regardless of age or comorbidity, in the first 60 days following diagnosis, being administered to 40.2% of patients. In contrast, administration of cyclophosphamide, doxorubicin, vincristine, or bendamustine in the first 60 days after diagnosis was less common (17.9%, 13.1%, 17.2%, and 12%, respectively). Overall survival was 3.23 (range, 0.003-7.668) years, and decreased with increasing number of comorbidities. DISCUSSION: Our analysis of a real-world patient population with MCL found that older patients have a high rate of comorbidities which impact administered treatment and subsequent OS. Our findings can be used to prospectively guide treatment decisions in these older, frailer, non-transplant-eligible patients, considering the impact of age and comorbidities on such choices.

Development of cutaneous squamous cell carcinoma after prolonged exposure to pegylated liposomal doxorubicin and hand-foot syndrome: a newly recognized toxicity.

Pegylated liposomal doxorubicin (PLD) can be administered for prolonged periods with minimal toxicity. The risk of cutaneous squamous cell carcinoma (SCC) with this therapy has not been reported. We describe cutaneous SCC of the plantar foot in two patients exposed to high doses of PLD. A 50-year-old man with angiosarcoma received a total PLD dose of 1350 mg/m2 and developed cutaneous SCC of bilateral plantar feet. A 45-year-old woman with cutaneous T-cell lymphoma was treated with a total PLD dose of 1142 mg/m2 with subsequent diagnosis of cutaneous SCC of the right plantar foot. No risk factors for SCC of the plantar foot were identified in either patient. Cutaneous SCC is likely an unreported side effect of prolonged exposure to PLD. An extended duration of hand-foot syndrome from other anti-cancer drugs may also share this risk. Regular complete skin examination with early intervention for suspicious lesions is indicated in this patient population.

Genome-wide identification of microRNAs regulating the human prion protein.

The cellular prion protein (PrPC ) is best known for its misfolded disease-causing conformer, PrPSc . Because the availability of PrPC is often limiting for prion propagation, understanding its regulation may point to possible therapeutic targets. We sought to determine to what extent the human microRNAome is involved in modulating PrPC levels through direct or indirect pathways. We probed PrPC protein levels in cells subjected to a genome-wide library encompassing 2019 miRNA mimics using a robust time-resolved fluorescence-resonance screening assay. Screening was performed in three human neuroectodermal cell lines: U-251 MG, CHP-212 and SH-SY5Y. The three screens yielded 17 overlapping high-confidence miRNA mimic hits, 13 of which were found to regulate PrPC biosynthesis directly via binding to the PRNP 3'UTR, thereby inducing transcript degradation. The four remaining hits (miR-124-3p, 192-3p, 299-5p and 376b-3p) did not bind either the 3'UTR or CDS of PRNP, and were therefore deemed indirect regulators of PrPC . Our results show that multiple miRNAs regulate PrPC levels both directly and indirectly. These findings may have profound implications for prion disease pathogenesis and potentially also for their therapy. Furthermore, the possible role of PrPC as a mediator of Aß toxicity suggests that its regulation by miRNAs may also impinge on Alzheimer's disease.

Somatic copy number gains of α-synuclein (SNCA) in Parkinson's disease and multiple system atrophy brains.

The α-synuclein protein, encoded by SNCA, has a key role in the pathogenesis of Parkinson's disease and other synucleinopathies. Although usually sporadic, Parkinson's disease can result from inherited copy number variants in SNCA and other genes. We have hypothesized a role of somatic SNCA mutations, leading to mosaicism, in sporadic synucleinopathies. The evidence for mosaicism in healthy and diseased brain is increasing rapidly, with somatic copy number gains of APP reported in Alzheimer's brain. Here we demonstrate somatic SNCA copy number gains in synucleinopathies (Parkinson's disease and multiple system atrophy), focusing on substantia nigra. We selected sporadic cases with relatively young onset or short disease duration, and first excluded high level copy number variant mosaicism by DNA analysis using digital PCR for SNCA, and/or customized array comparative genomic hybridization. To detect low level SNCA copy number variant mosaicism, we used fluorescent in situ hybridization with oligonucleotide custom-designed probes for SNCA, validated on brain and fibroblasts with known copy number variants. We determined SNCA copy number in nigral dopaminergic neurons and other cells in frozen nigra sections from 40 cases with Parkinson's disease and five with multiple system atrophy, and 25 controls, in a blinded fashion. Parkinson's disease cases were significantly more likely than controls to have any SNCA gains in dopaminergic neurons (P = 0.0036), and overall (P = 0.0052). The average proportion of dopaminergic neurons with gains in each nigra was significantly higher in Parkinson's disease than controls (0.78% versus 0.45%; P = 0.017). There was a negative correlation between the proportion of dopaminergic neurons with gains and onset age in Parkinson's disease (P = 0.013), but not with disease duration, or age of death in cases or controls. Cases with tremor at onset were less likely to have gains (P = 0.035). All multiple system atrophy cases had gains, and the highest levels in dopaminergic neurons were in two of these cases (2.76%, 2.48%). We performed selective validation with different probes after dye swapping. All three control probes used showed minimal or no gains (≤0.1% in dopaminergic neurons). We also found occasional SNCA gains in frontal neurons of cases with Parkinson's disease, and the putamen of one multiple system atrophy case. We present evidence of somatic SNCA gains in brain, more commonly in nigral dopaminergic neurons of Parkinson's disease than controls, negatively correlated with onset age, and possibly commonest in some multiple system atrophy cases. Somatic SNCA gains may be a risk factor for sporadic synucleinopathies, or a result of the disease process.10.1093/brain/awy157_video1awy157media15813519976001.

Treatment of mantle cell lymphoma in older adults.

Mantle cell lymphoma (MCL) predominantly affects older adults, with a median age at diagnosis of 70years. A frequently aggressive yet incurable lymphoma, the goal of therapy for MCL is to turn a potentially life-threatening illness into a chronic disease with prolonged periods of remission. Large randomized trial data supports the standard treatment in younger patients of cytarabine-based induction followed by autologous stem cell transplant. Most patients will not be eligible for this intensive approach based on older age, comorbidities, and functional status, making the geriatric assessment an essential step in choosing the appropriate strategy. For these older patients, an increasing number of chemotherapy and non-chemotherapy based therapies are available that allow oncologists to better tailor treatment to the fitness of the patient. We will review treatment options for older patients with MCL in the first line and relapsed/refractory settings, highlighting the available evidence for providing longer progression-free intervals while also minimizing the adverse effects of unduly aggressive treatment.

Oncolytic Viral Therapy for Mesothelioma.

The limited effectiveness of conventional therapy for malignant pleural mesothelioma demands innovative approaches to this difficult disease. Even with aggressive multimodality treatment of surgery, radiation, and/or chemotherapy, the median survival is only 1-2 years depending on stage and histology. Oncolytic viral therapy has emerged in the last several decades as a rapidly advancing field of immunotherapy studied in a wide spectrum of malignancies. Mesothelioma makes an ideal candidate for studying oncolysis given the frequently localized pattern of growth and pleural location providing access to direct intratumoral injection of virus. Therefore, despite being a relatively uncommon disease, the multitude of viral studies for mesothelioma can provide insight for applying such therapy to other malignancies. This article will begin with a review of the general principles of oncolytic therapy focusing on antitumor efficacy, tumor selectivity, and immune system activation. The second half of this review will detail results of preclinical models and human studies for oncolytic virotherapy in mesothelioma.

Differences in community and academic practice patterns for newly diagnosed myelodysplastic syndromes (MDS) patients.

PURPOSE: The heterogeneous nature of myelodysplastic syndromes (MDS) complicates therapeutic decision making, particularly for newly diagnosed disease. Factors impacting the treatment plan in this early period of disease course are poorly defined. This study determines whether therapeutic choices for newly diagnosed MDS are associated with location of treatment (community or academic), prognostic risk category, and patient age. METHODS: The adults in Minnesota with myelodysplastic syndromes (AIMMS) database was utilized in this statewide, prospective population-based study conducted by the University of Minnesota (UMN), Mayo Clinic, and Minnesota Department of Health. Adult (age 20+ years) cases of MDS newly diagnosed starting in April 2010 were invited to participate. This analysis includes patients enrolled during the first study year with 1-year follow-up data. Treatment choices (supportive, active, and transplant) were stratified by the international prognostic scoring system (IPSS) and the revised-IPSS (IPSS-R), then separated into groups by location of care and age (<65 or 65+ years). Academic-based care was any contact with the UMN and Mayo Clinic; community-based care was all other clinical sites. RESULTS: Stratification by IPSS and IPSS-R showed supportive care decreased and active care increased with advancing risk categories (p<0.0001). Comparing treatment setting, community-based care had 77% supportive and 23% active treatment; academic-based care was 36% supportive, 41% active, and 23% transplant (p<0.0001). By age groups, patients <65 years with intermediate, high, or very high risk disease by IPSS-R received 97% active care/transplant, compared to only 52% of patients age 65+. CONCLUSIONS: Younger patients and those treated at academic centers had a more aggressive treatment approach. Whether these treatment differences convey improved disease control and mortality, and therefore should be extended more frequently to older and community-based patients, is the subject of ongoing prospective study.