Genome-wide profiling of rice Double-stranded RNA-Binding Protein 1-associated RNAs by targeted RNA editing.

RNA-binding proteins (RBPs) play essential roles in regulating gene expression. However, the RNA ligands of RBPs are poorly understood in plants, not least due to the lack of efficient tools for genome-wide identification of RBP-bound RNAs. An RBP-fused adenosine deaminase acting on RNA (ADAR) can edit RBP-bound RNAs, which allows efficient identification of RNA ligands of RBPs in vivo. Here, we report the RNA editing activities of the ADAR deaminase domain (ADARdd) in plants. Protoplast experiments indicated that RBP-ADARdd fusions efficiently edited adenosines within 41 nucleotides (nt) of their binding sites. We then engineered ADARdd to profile the RNA ligands of rice (Oryza sativa) Double-stranded RNA-Binding Protein 1 (OsDRB1). Overexpressing the OsDRB1-ADARdd fusion protein in rice introduced thousands of A-to-G and T-to-C RNA‒DNA variants (RDVs). We developed a stringent bioinformatic approach to identify A-to-I RNA edits from RDVs, which removed 99.7% to 100% of background single-nucleotide variants in RNA-seq data. This pipeline identified a total of 1,798 high-confidence RNA editing (HiCE) sites, which marked 799 transcripts as OsDRB1-binding RNAs, from the leaf and root samples of OsDRB1-ADARdd-overexpressing plants. These HiCE sites were predominantly located in repetitive elements, 3'-UTRs, and introns. Small RNA sequencing also identified 191 A-to-I RNA edits in miRNAs and other sRNAs, confirming that OsDRB1 is involved in sRNA biogenesis or function. Our study presents a valuable tool for genome-wide profiling of RNA ligands of RBPs in plants and provides a global view of OsDRB1-binding RNAs.

Fine-tuning OsCPK18/OsCPK4 activity via genome editing of phosphorylation motif improves rice yield and immunity.

Plants have evolved complex signalling networks to regulate growth and defence responses under an ever-changing environment. However, the molecular mechanisms underlying the growth-defence tradeoff are largely unclear. We previously reported that rice CALCIUM-DEPENDENT PROTEIN KINASE 18 (OsCPK18) and MITOGEN-ACTIVATED PROTEIN KINASE 5 (OsMPK5) mutually phosphorylate each other and that OsCPK18 phosphorylates and positively regulates OsMPK5 to suppress rice immunity. In this study, we found that OsCPK18 and its paralog OsCPK4 positively regulate plant height and yield-related traits. Further analysis reveals that OsCPK18 and OsMPK5 synergistically regulate defence-related genes but differentially regulate development-related genes. In vitro and in vivo kinase assays demonstrated that OsMPK5 phosphorylates C-terminal threonine (T505) and serine (S512) residues of OsCPK18 and OsCPK4, respectively. The kinase activity of OsCPK18T505D , in which T505 was replaced by aspartic acid to mimic T505 phosphorylation, displayed less calcium sensitivity than that of wild-type OsCPK18. Interestingly, editing the MAPK phosphorylation motif in OsCPK18 and its paralog OsCPK4, which deprives OsMPK5-mediated phosphorylation but retains calcium-dependent activation of kinase activity, simultaneously increases rice yields and immunity. This editing event also changed the last seven amino acid residues of OsCPK18 and attenuated its binding with OsMPK5. This study presents a new regulatory circuit that fine tunes the growth-defence tradeoff by modulating OsCPK18/4 activity and suggests that CRISPR/Cas9-mediated engineering phosphorylation pathways could simultaneously improve crop yield and immunity.

Tumor-intrinsic PRC2 inactivation drives a context-dependent immune-desert microenvironment and is sensitized by immunogenic viruses.

Immune checkpoint blockade (ICB) has demonstrated clinical success in "inflamed" tumors with substantial T cell infiltrates, but tumors with an immune-desert tumor microenvironment (TME) fail to benefit. The tumor cell-intrinsic molecular mechanisms of the immune-desert phenotype remain poorly understood. Here, we demonstrated that inactivation of the polycomb-repressive complex 2 (PRC2) core components embryonic ectoderm development (EED) or suppressor of zeste 12 homolog (SUZ12), a prevalent genetic event in malignant peripheral nerve sheath tumors (MPNSTs) and sporadically in other cancers, drove a context-dependent immune-desert TME. PRC2 inactivation reprogramed the chromatin landscape that led to a cell-autonomous shift from primed baseline signaling-dependent cellular responses (e.g., IFN-γ signaling) to PRC2-regulated developmental and cellular differentiation transcriptional programs. Further, PRC2 inactivation led to diminished tumor immune infiltrates through reduced chemokine production and impaired antigen presentation and T cell priming, resulting in primary resistance to ICB. Intratumoral delivery of inactivated modified vaccinia virus Ankara (MVA) enhanced tumor immune infiltrates and sensitized PRC2-loss tumors to ICB. Our results identify molecular mechanisms of PRC2 inactivation-mediated, context-dependent epigenetic reprogramming that underline the immune-desert phenotype in cancer. Our studies also point to intratumoral delivery of immunogenic viruses as an initial therapeutic strategy to modulate the immune-desert TME and capitalize on the clinical benefit of ICB.

Non-Myeloablative Chemotherapy as Consolidation Strategy After High-Dose Methotrexate-Based Chemoimmunotherapy in Patients With Primary CNS Lymphoma: A Retrospective Single Center Study in China.

Primary central nervous system lymphoma (PCNSL) remains a disease with poor outcome and high recurrence rate. We retrospectively analyzed the clinical data of 243 immunocompetent patients with PCNSL in Beijing Tiantan Hospital. The median age of PCNSL patients was 57 years (range 10-95 years). For induction therapy, 94.7% of patients received high-dose methotrexate (HD-MTX) containing regimens, and 59.3% received rituximab, which increased over time. The overall response rate was 72.8%, with 58.8% achieving complete response. With a median follow-up of 27.0 months (95% confidence interval 23.6-30.4), the median progression-free survival (PFS) time was 14.0 months (95% CI 9.45-18.55), and the 2-year PFS rate was 33.2%. The median overall survival (OS) was not reached (NR), with an estimated overall survival rate at 4 years of 61.6%. Among 95 patients who completed sequential consolidation chemotherapy with either pemetrexed or etoposide plus cytarabine, the median PFS was 28 months (95% CI 17.11-38.89), and the estimated overall survival at 4 years was 78.7%. In conclusion, HD-MTX based induction chemotherapy with non-myeloablative sequential consolidation chemotherapy is an alternative feasible treatment option.

Efficacy and Safety of Ibrutinib in Central Nervous System Lymphoma: A PRISMA-Compliant Single-Arm Meta-Analysis.

BACKGROUND: Central nervous system lymphoma (CNSL) is an aggressive lymphoma. Studies investigating primary CNSL determined that the Bruton tyrosine kinase (BTK) played an important role in pathogenesis. Ibrutinib, an oral BTK inhibitor, is a new treatment strategy for CNSL. The purpose of this meta-analysis was to clarify the effectiveness and safety of ibrutinib in the treatment of CNSL. METHODS: A systematic search of PubMed, Embase, Cochrane library, Wanfang Data Knowledge Service Platform, and China National Knowledge Infrastructure databases was conducted through to 31 October 2019. Studies involving patients with CNSL who received ibrutinib that reported the overall response (OR), complete remission (CR), and partial response (PR) were included. The random-effects or fixed-effects model with double arcsine transformation was used for the pooled rates and 95% confidence intervals (CI) were determined for all outcomes. RESULTS: Eight studies including 162 patients were identified and included in the meta-analysis. The pooled OR rate after treatment with ibrutinib was 69% (95% CI, 61-79%, I2 = 47.57%, p = 0.06), while the pooled CR and PR was 52% (95% CI, 35-68%, I2 = 74.95%, p = 0.00) and 17% (95% CI, 7-30%, I2 = 67.85%, p = 0.00), respectively. Among PCNSL patients, including new diagnoses PCNSL and R/R PCNSL, the pooled OR rate was 72% (95% CI, 63-80%, I2 = 49.20%, p = 0.06) while the pooled CR and PR rates were 53% (95% CI, 33-73%, I2 = 75.04%, p = 0.00) and 22% (95% CI, 14-30%, I2 = 46.30%, p = 0.07), respectively. Common adverse events above grade 3 included cytopenia and infections. CONCLUSIONS: The ibrutinib-containing therapy was well tolerated and offered incremental benefit to patients with CNSL. However, randomized-controlled studies that directly compare efficacy and adverse events of ibrutinib are still needed. SYSTEMATIC REVIEW REGISTRATION: https://www.crd.york.ac.uk/prospero/, identifier CRD42020218974.

Treatment of secondary central nervous system involvement in systemic aggressive B cell lymphoma using R-MIADD chemotherapy: a single-center study.

BACKGROUND: Secondary central nervous system lymphoma (SCNSL) is defined as lymphoma involvement within the central nervous system (CNS) that originated elsewhere, or a CNS relapse of systemic lymphoma. Prognosis of SCNSL is poor and the most appropriate treatment is still undetermined. METHODS: We conducted a retrospective study to assess the feasibility of an R-MIADD (rituximab, high-dose methotrexate, ifosfamide, cytarabine, liposomal formulation of doxorubicin, and dexamethasone) regimen for SCNSL patients. RESULTS: Nineteen patients with newly diagnosed CNS lesions were selected, with a median age of 58 (range 20 to 72) years. Out of 19 patients, 11 (57.9%) achieved complete remission (CR) and 2 (10.5%) achieved partial remission (PR); the overall response rate was 68.4%. The median progression-free survival after CNS involvement was 28.0 months (95% confidence interval 11.0-44.9), and the median overall survival after CNS involvement was 34.5 months. Treatment-related death occurred in one patient (5.3%). CONCLUSIONS: These single-centered data underscore the feasibility of an R-MIADD regimen as the induction therapy of SCNSL, further investigation is warranted.

Expression of hypoxia-inducible factor 1α, glucose transporter 1, and hexokinase 2 in primary central nervous system lymphoma and the correlation with the biological behaviors.

BACKGROUND: It has been indicated that abnormal glucose metabolism mediated by hypoxia-inducible factor 1α (HIF-1α) played an essential role in the development of solid tumor. However, there were rare studies about the role of them in primary central nervous system lymphoma (PCNSL). OBJECTIVE: To investigate the protein levels of HIF-1α, glucose transporter 1 (GLUT1), and hexokinase 2 (HK2) in PCNSL and whether their levels are associated with prognostic factors. METHODS: Expression of HIF-1α, GLUT1, and HK2 in 39 tumor tissues was evaluated by immunohistochemical stainning. The correlation of the expression of HIF-1α with the protein level of GLUT1 and HK2 was investigated. In addition, the association between these protein expression levels and clinical parameters and prognosis was analyzed. RESULTS: In the tumor specimens of PCNSL, positive stainings of HIF-1α, GLUT1, and HK2 were in 23 patients (58.97%), 25 patients (64.1%), and 26 patients (66.67%), respectively, which were associated with the expression level of lactic dehydrogenase (LDH), but not with age, gender, number of lesion, ECOG score, or deep structure. The expression of HIF-1α was positively correlated with the expression of GLUT1 (p < .01, r = .749) and HK2 (p < .01, r = .787). Univariate analysis showed that upregulated GLUT1 was unfavorable predictors of progression-free survival (PFS) in PCNSL. The results of Cox proportional hazards model showed GLUT1 was significantly associated with shorter PFS (hazard ration: 5.65; 95% confidence interval: 1.23-25.84; p = .026). CONCLUSIONS: This study indicated that there was a hypoxic microenvironment and HIF-1α was involved in the regulation of glycolysis pathway in PCNSL. GLUT1 might be a potential marker for shorter PFS in PCNSL.

STAT3 Activation Is Associated with Interleukin-10 Expression and Survival in Primary Central Nervous System Lymphoma.

BACKGROUND: The findings from several studies have confirmed that signal transducer and activator of transcription 3 (STAT3) is constitutively phosphorylated in primary central nervous system lymphoma (PCNSL). However, the underlying mechanism and prognostic significance of STAT3 activation have not yet been clarified. METHODS: The expression of STAT3, phosphorylated STAT3 (p-STAT3), and interleukin (IL)-10 was examined in 32 PCNSL samples using immunohistochemistry. The relationship between IL-10 expression and STAT3 phosphorylation was determined. In addition, the associations of the expression of these proteins with the clinical factors and survival were analyzed. RESULTS: Expression of STAT3, p-STAT3, and IL-10 was detected in 28 (87.5%), 17 (53.1%), and 25 (78.1%) samples, respectively. IL-10 expression was significantly associated with STAT3 phosphorylation in PCNSL (P = 0.033). STAT3 phosphorylation and IL-10 expression were associated with the presence of multiple brain lesions (P = 0.004 and P = 0.027, respectively), suggesting that STAT3 activation might enhance the intracranial spread of tumors in PCNSL. The 2-year overall survival and progression-free survival (PFS) rates were 67.8% and 35.5%, respectively. Kaplan-Meier survival analysis demonstrated that STAT3 phosphorylation, IL-10 expression, and multiple brain lesions were significantly associated with PFS in those with PCNSL (P = 0.009, P = 0.030, and P = 0.040, respectively). However, Cox regression analysis indicated that only STAT3 phosphorylation was significantly associated with shorter PFS (hazard ratio, 3.22; 95% confidence interval, 1.24-8.37; P = 0.016). CONCLUSION: Our results have indicated that STAT3 activation is closely related to IL-10 expression and that p-STAT3 might be a novel biomarker predictive of poor survival in those with PCNSL.

Parenchymal central nervous system involvement in aggressive B-cell lymphoma: retrospective analysis of clinical and MRI features in a Chinese population.

BACKGROUND: Secondary central nervous system lymphoma (SCNSL) is defined as secondary central nervous system (CNS) involvement in patients with systemic lymphoma. It is considered a profoundly adverse complication with inferior clinical outcome. Parenchymal involvement in the CNS in aggressive B-cell lymphoma is not frequently seen and remains a diagnostic dilemma. METHODS: In our study, we retrospectively analyzed the clinical and magnetic resonance imaging (MRI) features of 26 parenchymal SCNSL patients. In addition, we compared MRI features of SCNSL and primary CNS lymphoma (PCNSL) patients after 1:1 propensity score matching. Also we presented two SCNSL cases with atypical MRI appearance. RESULTS: Among SCNSL patients, the median CNS relapse time was 3 months, and multiple lesions were found in 76.9% of the cases. In PCNSL, this percentage was 42.3% (p = 0.011). None of the SCNSL patients and 23.1% of the PCNSL patients had solitary infratentorial lesions (p = 0.003). CONCLUSIONS: The majority of parenchymal involvement occurred within the first year of systemic lymphoma, in which mostly cases presenting with multiple and supratentorial locations, unlike what was found in PCNSL.

Engineering Introns to Express RNA Guides for Cas9- and Cpf1-Mediated Multiplex Genome Editing.

The clustered regularly interspaced short palindromic repeat (CRISPR) system has emerged as the revolutionary platform for DNA targeting. This system uses a site-specific RNA guide to direct a CRISPR effector (e.g., Cas9 and Cpf1) to a DNA target. Here, we elaborate a general strategy to simultaneously express multiple guide RNAs (gRNA) and CRISPR RNAs (crRNA) from introns of Cas9 and Cpf1. This method utilizes the endogenous tRNA processing system or crRNA processing activity of Cpf1 to cleave the spliced intron that contains tRNA-gRNA polycistron or crRNA-crRNA array. We demonstrated that the tRNA-gRNA intron is able to fuse with Cas9 as one gene. Such a hybrid gene could be expressed using one polymerase II promoter, and exhibited high efficiency and robustness in simultaneously targeting multiple sites. We also implemented this strategy in Cpf1-mediated genome editing using intronic tRNA-crRNA and crRNA-crRNA arrays. Interestingly, hybrid genes containing Cpf1 and intronic crRNA array exhibited remarkably increased efficiency compared with the conventional Cpf1 vectors. Taken together, this study presents a method to express CRISPR reagents from one hybrid gene to increase genome-editing efficiency and capacity. Owing to its simplicity and versatility, this method could be broadly used to develop sophisticated CRISPR tools in eukaryotes.

Interstitial pneumonitis during rituximab-containing chemotherapy for primary central nervous system lymphomas: a case report and review of literature.

BACKGROUND: Primary central nervous system lymphoma(PCNSL) is a rare kind of non-Hodgkin lymphoma. Rituximab combined with high-dose methotrexate, cytarabine and dexamethasone (R-MAD regimen) were reported effective for PCNSL patients. Rituximab can cause several side effects, including fever, chills and rigors. CASE PRESENTATION: In this case report, we demonstrate rituximab-induced interstitial pneumonitis in a PCNSL patient who has been treated with R-MAD regimen. The patient recovered after treatment and she remains complete remission after following consolidation chemotherapy. CONCLUSIONS: Here is no report of potential fatal complications of Rituximab like interstitial pneumonitis nowadays in PCNSL patients. As Rituximab is widely used, physicians should raise their awareness of this rare complication and detect RTX-ILD in early stage.

FOXF1 Defines the Core-Regulatory Circuitry in Gastrointestinal Stromal Tumor.

The cellular context that integrates upstream signaling and downstream nuclear response dictates the oncogenic behavior and shapes treatment responses in distinct cancer types. Here, we uncover that in gastrointestinal stromal tumor (GIST), the forkhead family member FOXF1 directly controls the transcription of two master regulators, KIT and ETV1, both required for GIST precursor-interstitial cells of Cajal lineage specification and GIST tumorigenesis. Further, FOXF1 colocalizes with ETV1 at enhancers and functions as a pioneer factor that regulates the ETV1-dependent GIST lineage-specific transcriptome through modulation of the local chromatin context, including chromatin accessibility, enhancer maintenance, and ETV1 binding. Functionally, FOXF1 is required for human GIST cell growth in vitro and murine GIST tumor growth and maintenance in vivo The simultaneous control of the upstream signaling and nuclear response sets up a unique regulatory paradigm and highlights the critical role of FOXF1 in enforcing the GIST cellular context for highly lineage-restricted clinical behavior and treatment response.Significance: We uncover that FOXF1 defines the core-regulatory circuitry in GIST through both direct transcriptional regulation and pioneer factor function. The unique and simultaneous control of signaling and transcriptional circuitry by FOXF1 sets up an enforced transcriptional addiction to FOXF1 in GIST, which can be exploited diagnostically and therapeutically. Cancer Discov; 8(2); 234-51. ©2017 AACR.See related commentary by Lee and Duensing, p. 146This article is highlighted in the In This Issue feature, p. 127.

Aberrant Activation of a Gastrointestinal Transcriptional Circuit in Prostate Cancer Mediates Castration Resistance.

Prostate cancer exhibits a lineage-specific dependence on androgen signaling. Castration resistance involves reactivation of androgen signaling or activation of alternative lineage programs to bypass androgen requirement. We describe an aberrant gastrointestinal-lineage transcriptome expressed in ∼5% of primary prostate cancer that is characterized by abbreviated response to androgen-deprivation therapy and in ∼30% of castration-resistant prostate cancer. This program is governed by a transcriptional circuit consisting of HNF4G and HNF1A. Cistrome and chromatin analyses revealed that HNF4G is a pioneer factor that generates and maintains enhancer landscape at gastrointestinal-lineage genes, independent of androgen-receptor signaling. In HNF4G/HNF1A-double-negative prostate cancer, exogenous expression of HNF4G at physiologic levels recapitulates the gastrointestinal transcriptome, chromatin landscape, and leads to relative castration resistance.

Methotrexate-cytarabine-dexamethasone combination chemotherapy with or without rituximab in patients with primary central nervous system lymphoma.

PURPOSE: High-dose methotrexate based chemotherapy is the standard treatment for patients with newly diagnosed primary central nervous system lymphoma (PCNSL). The role of rituximab is controversial because of its large size, which limits its penetration of the blood-brain barrier. In this study, we investigated the efficacy and tolerability of adding rituximab to methotrexate-cytarabine-dexamethasone combination therapy (RMAD regimen). RESULTS: The patients treated with RMAD had a complete remission rate of 66.7% after induction chemotherapy; this rate was only 33.3% in patients treated with MAD alone (p = .011). The most common grade 1-3 adverse events were similar and included hematologic toxicity, increased aminotransferase levels, and gastrointestinal reactions. Multivariate analysis revealed that rituximab treatment was associated with longer progression-free survival (PFS, p = .005) but not overall survival (OS). Additionally, we observed that elevated serum lactate dehydrogenase was associated with shorter OS and PFS. MATERIALS AND METHODS: We retrospectively analyzed 60 immunocompetent patients with newly diagnosed PCNSL at Beijing Tiantan Hospital, Capital Medical University from January 2010 to June 2016. Twenty-four patients received 3-6 courses of 3.5 g/m2 methotrexate on day 1; 0.5-1 g/m2 cytarabine on day 2; and 5-10 mg dexamethasone on days 1, 2 and 3. Thirty-six patients received the same combination plus rituximab 375 mg/m2 on day 0. All patients repeated the treatment every 3 weeks. CONCLUSIONS: High-dose methotrexate based chemotherapy with rituximab yields a higher complete remission rate and does not increase serious toxicities. PFS benefits from the addition of rituximab. OS has an increasing trend in patients treated with rituximab without statistical significance.

Immunochemotherapy for primary central nervous system lymphoma with rituximab, methotrexate, cytarabine and dexamethasone: Retrospective analysis of 18 cases.

The incidence of primary central nervous system lymphoma (PCNSL) has increased in the last two decades and the clinical research regarding the treatment for PCNSL patients has also increased. However, the optimal induction chemotherapy has not been fully established. In the present retrospective study, the aim was to analyze the outcome in PCNSL patients treated with the combination of rituximab, methotrexate (MTX), cytarabine (Ara-C) and dexamethasone (R-MAD). Eighteen patients from Beijing Tiantan Hospital (Beijing, China) between January 2010 and March 2014 were newly diagnosed with PCNSL [diffuse large B-cell lymphoma (DLBCL) type] and received R-MAD as first-line treatment. The dosage was as follows: 375 mg/m2 rituximab was administered on day 0, 3.5 g/m2 MTX was administered on day 1, 1 g/m2 Ara-C was administered on day 2 and 10 mg dexamethasone was administered on days 1-3, every 3 weeks. After 6 cycles, the overall response rate was 94.5%. Ten (55.6%) patients achieved complete response (CR), 7 (38.9%) achieved partial response (PR) and 1 (5.6%) had progressive disease (PD). Patients were followed up from the start of the treatment, median 24.2 months (range 6-48). The overall survival (OS) rate was 94.5% and progression-free survival rate was 94.5%. The median OS was 22 months (95% confidence interval, 19.4-24.6). The high level of serum lactate dehydrogenase (LDH) concentration was associated with a poor outcome. Among 5 patients with an abnormally high LDH concentration, 1 achieved CR, 3 had PR and 1 had PD. None of the patients experienced any grade 4 toxicity. These results indicated that the R-MAD immunochemotherapy regimen is effective in PCNSL patients without serious toxicity. A prospective investigation with more patients should be administered in order to understand the more accurate effect of the regimen.

Combined inhibition of MAP kinase and KIT signaling synergistically destabilizes ETV1 and suppresses GIST tumor growth.

UNLABELLED: Gastrointestinal stromal tumor (GIST), originating from the interstitial cells of Cajal (ICC), is characterized by frequent activating mutations of the KIT receptor tyrosine kinase. Despite the clinical success of imatinib, which targets KIT, most patients with advanced GIST develop resistance and eventually die of the disease. The ETS family transcription factor ETV1 is a master regulator of the ICC lineage. Using mouse models of Kit activation and Etv1 ablation, we demonstrate that ETV1 is required for GIST initiation and proliferation in vivo, validating it as a therapeutic target. We further uncover a positive feedback circuit where MAP kinase activation downstream of KIT stabilizes the ETV1 protein, and ETV1 positively regulates KIT expression. Combined targeting of ETV1 stability by imatinib and MEK162 resulted in increased growth suppression in vitro and complete tumor regression in vivo. The combination strategy to target ETV1 may provide an effective therapeutic strategy in GIST clinical management. SIGNIFICANCE: ETV1 is a lineage-specific oncogenic transcription factor required for the growth and survival of GIST. We describe a novel strategy of targeting ETV1 protein stability by the combination of MEK and KIT inhibitors that synergistically suppress tumor growth. This strategy has the potential to change first-line therapy in GIST clinical management.

Retargeting T cells to GD2 pentasaccharide on human tumors using Bispecific humanized antibody.

Anti-disialoganglioside GD2 IgG antibodies have shown clinical efficacy in solid tumors that lack human leukocyte antigens (e.g., neuroblastoma) by relying on Fc-dependent cytotoxicity. However, there are pain side effects secondary to complement activation. T-cell retargeting bispecific antibodies (BsAb) also have clinical potential, but it is thus far only effective against liquid tumors. In this study, a fully humanized hu3F8-BsAb was developed, in which the anti-CD3 huOKT3 single-chain Fv fragment (ScFv) was linked to the carboxyl end of the anti-GD2 hu3F8 IgG1 light chain, and was aglycosylated at N297 of Fc to prevent complement activation and cytokine storm. In vitro, hu3F8-BsAb activated T cells through classic immunologic synapses, inducing GD2-specific tumor cytotoxicity at femtomolar EC50 with >105-fold selectivity over normal tissues, releasing Th1 cytokines (TNFα, IFNγ, and IL2) when GD2⁺ tumors were present. In separate murine neuroblastoma and melanoma xenograft models, intravenous hu3F8-BsAb activated T cells in situ and recruited intravenous T cells for tumor ablation, significantly prolonging survival from local recurrence or from metastatic disease. Hu3F8-BsAb, but not control BsAb, drove T cells and monocytes to infiltrate tumor stroma. These monocytes were necessary for sustained T-cell proliferation and/or survival and contributed significantly to the antitumor effect. The in vitro and in vivo antitumor properties of hu3F8-BsAb and its safety profile support its further clinical development as a cancer therapeutic, and provide the rationale for exploring aglycosylated IgG-scFv as a structural platform for retargeting human T cells.

The variable hinge region of novel PKCs determines localization to distinct regions of the immunological synapse.

The immunological synapse (IS) formed between a T cell and its cognate antigen-presenting cell (APC) enables the directional secretion of cytolytic and inflammatory molecules. Synaptic architecture is established in part by a two-step cascade of novel protein kinase C (nPKC) isozymes. PKCε and PKCη arrive at the IS first, and occupy the entire synaptic membrane. Then, PKCθ accumulates in a smaller zone at the center of the contact. We investigated the molecular basis for this differential recruitment behavior using chimeric nPKC constructs and total internal reflection fluorescence microscopy. Our studies revealed that the V3 linker just N-terminal to the kinase domain plays a crucial role in specifying nPKC localization. Substitution of this linker switched the scope and the kinetics of PKCθ accumulation to that of PKCε and PKCη, and vice versa. Although the V3 was necessary for synaptic compartmentalization, it was not sufficient, as the tandem C1 domains were also required to mediate membrane association. Together, these results suggest a model whereby the V3 linker controls nPKC sub-compartmentalization after initial C1 domain-mediated accumulation at the IS.

[Clinical features and survival analysis in primary myelodysplastic syndromes patients with immunological abnormalities].

OBJECTIVE: To analyze the clinical features and survival time in primary myelodysplastic syndromes (MDS) patients accompanied with immunological abnormalities. METHODS: The clinical information, laboratory findings and survival time in 194 untreated primary MDS patients with complete immunological laboratory tests or a past history of autoimmune disease were analyzed retrospectively. RESULTS: There were 37/194 cases (19.07%) with autoimmune abnormalities, including 16/194 (8.25%) with autoimmune disease and 21/194 asymptomatic cases (10.82%) with serologic immunological abnormalities only. There was significant differences in the distribution of age < 60 years old, female, CD4(+)T-cell/CD8(+)T-cell ration < 1 and trisomy 8 (P < 0.05) between the cases with autoimmune disease and without autoimmune abnormalities. The former had a higher 2-year OS, but there was no significance (P = 0.065). There was no significant differences in the distribution of age, MDS-subtype, IPSS risk groups, haemoglobin, absolute neutrophil count, platelets count, the severity of anemia and neutropenia, high level of serologic TNF, chromosomal abnormalities, cytogenetic risk groups and bone marrow cellularity (P > 0.05). CONCLUSION: MDS patients with autoimmune disease are mainly female and younger than 60 years old, with high proportion of trisomy 8 and better prognosis.

[A preliminary study of prognostic value of thrombocytopenia in patients with primary myelodysplastic syndromes].

OBJECTIVE: To investigate the prognostic value of thrombocytopenia in patients with primary myelodysplastic syndromes (MDS). METHODS: Four hundred and nineteen primary MDS patients were retrospectively analyzed. Kaplan-Meier method, Log-rank test and COX regression model were used to evaluate factors that influence the prognosis. RESULTS: Two hundred and fifty-six cases (61.1%) had thrombocytopenia (PLT < 100×10(9)/L), one hundred and three cases (24.6%) had severe thrombocytopenia (PLT < 30×10(9)/L). Overall survival (OS) tended to shorten along with the decreasing of platelet count. Univariate analysis indicated that PL < 30×10(9)/L, MCV ≤ 95 fl, LDH ≥ 300 U/L, lymphocyte-like micromegakaryocyte, nucleated RBC PAS positive, IPSS cytogenetic intermediate- and poor-risk were all related with poor prognosis. Moreover, the prognosis of patients with RCMD, RAEB-Ior RAEB-IIwas poorer than that of the other subgroups. Among these parameters, PLT < 30×10(9)/L, MCV ≤ 95 fl, IPSS cytogenetic intermediate- and poor-risk group and RCMD, RAEB-I and RAEB-II had independent prognostic significance in multivariate analysis. Modified WPSS prognostic model was proposed by adopting PLT, MCV, chromosomal karyotype and WHO classification. The OS of patients with low risk, intermediate-1 risk, intermediate-2 risk and high risk were 59, 28, 14 and 4 months, respectively, and there was a statistically significant difference between the groups (P < 0.05). CONCLUSION: Severe thrombocytopenia indicated unfavorable prognosis, in combination with MCV, chromosomal karyotype and WHO classification, a modified WPSS prognostic model was proposed and worked well for prognostic indication in patients with MDS.