In this task, you are given an abstract of article. Your task is to generate title for this article. Preferred titles are under thirty words.

Q: In many eukaryotes, RNA-dependent RNA polymerases (RdRPs) play key roles in the RNAi pathway. They have been implicated in the recognition and processing of aberrant transcripts triggering the process, and in amplification of the silencing response. We have tested the functions of RdRP genes from the ciliate Paramecium tetraurelia in experimentally induced and endogenous mechanisms of gene silencing. In this organism, RNAi can be triggered either by high-copy, truncated transgenes or by directly feeding cells with double-stranded RNA (dsRNA). Surprisingly, dsRNA-induced silencing depends on the putatively functional RDR1 and RDR2 genes, which are required for the accumulation of both primary siRNAs and a distinct class of small RNAs suggestive of secondary siRNAs. In contrast, a third gene with a highly divergent catalytic domain, RDR3, is required for siRNA accumulation when RNAi is triggered by truncated transgenes. Our data further implicate RDR3 in the accumulation of previously described endogenous siRNAs and in the regulation of the surface antigen gene family. While only one of these genes is normally expressed in any clonal cell line, the knockdown of RDR3 leads to co-expression of multiple antigens. These results provide evidence for a functional specialization of Paramecium RdRP genes in distinct RNAi pathways operating during vegetative growth.

A: Distinct RNA-dependent RNA polymerases are required for RNAi triggered by double-stranded RNA versus truncated transgenes in Paramecium tetraurelia
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Q: Although susceptibility of neurons in the brain to microbial infection is a major determinant of clinical outcome, little is known about the molecular factors governing this vulnerability. Here we show that two types of neurons from distinct brain regions showed differential permissivity to replication of several positive-stranded RNA viruses. Granule cell neurons of the cerebellum and cortical neurons from the cerebral cortex have unique innate immune programs that confer differential susceptibility to viral infection ex vivo and in vivo. By transducing cortical neurons with genes that were expressed more highly in granule cell neurons, we identified three interferon-stimulated genes (ISGs; Ifi27, Irg1 and Rsad2 (also known as Viperin)) that mediated the antiviral effects against different neurotropic viruses. Moreover, we found that the epigenetic state and microRNA (miRNA)-mediated regulation of ISGs correlates with enhanced antiviral response in granule cell neurons. Thus, neurons from evolutionarily distinct brain regions have unique innate immune signatures, which probably contribute to their relative permissiveness to infection.

A: Differential innate immune response programs in neuronal subtypes determine susceptibility to infection in the brain by positive stranded RNA viruses
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Q: PURPOSE Gleason score (GS), T stage, and pathologic lymph node status have been described as major independent predictors of death due to prostate cancer in men treated with external beam radiotherapy (XRT). In this analysis we combine these three factors to define prognostic subgroups that correlate with disease-specific survival (DSS) death from prostate cancer.
METHODS AND MATERIALS Men entered on one of four Radiation Therapy Oncology Group (RTOG) Phase III randomized trials between 1975 and 1992, for clinically localized prostate cancer (CAP) (n = 1557), were selected for this analysis. Patients were included if: 1) they were evaluable, and eligible for the trial; 2) they received no hormonal therapy with their initial treatment; and 3) follow-up was available. For this study a DSS event was declared if: 1) death was certified as due to CAP; 2) death was due to complications of treatment; or 3) death was from unknown causes with active malignancy. The median follow-up for patients treated on early and late RTOG studies exceeded 11 and 6 years respectively. Subgroups were identified based on their pretreatment GS, T-stage, and lymph node such that patients with similar risk of dying from prostate cancer were combined.
RESULTS By combining patients with similar DSS, four subgroups were identified. Risk Group 1 patients had a GS = 2-6, and T1-2Nx; Group 2: GS = 2-6, T3Nx; or GS = 2-6, N+, or GS = 7, T1-2Nx; Group 3: T3Nx, GS = 7; or N+, GS = 7, or T1-2Nx, GS = 8-10; and Group 4 patients were T3Nx, GS = 8-10, or N+, GS = 8-10. The 5-, 10-, and 15-year DSS was 96%, 86%, and 72%; 94%, 75%, and 61%; 83%, 62%, and 39%; and 64%, 34%, and 27% for Groups 1 through 4, respectively.
CONCLUSIONS Recognition of these four risk groups provides a basis for estimating the long-term DSS for men treated with XRT alone and should facilitate the design of future prospective randomized trials.

A:
Four prognostic groups predict long-term survival from prostate cancer following radiotherapy alone on Radiation Therapy Oncology Group clinical trials.
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