Development of a Single Vector System that Enhances Trans-Splicing of SMN2 Transcripts

RNA modalities are developing as a powerful means to re-direct pathogenic pre-mRNA splicing events. Improving the efficiency of these molecules in vivo is critical as they move towards clinical applications. Spinal muscular atrophy (SMA) is caused by loss of SMN1. A nearly identical copy gene called SMN2 produces low levels of functional protein due to alternative splicing. We previously reported a trans-splicing RNA (tsRNA) that re-directed SMN2 splicing. Now we show that reducing the competition between endogenous splices sites enhanced the efficiency of trans-splicing. A single vector system was developed that expressed the SMN tsRNA and a splice-site blocking antisense (ASO-tsRNA). The ASO-tsRNA vector significantly elevated SMN levels in primary SMA patient fibroblasts, within the central nervous system of SMA mice and increased SMN-dependent in vitro snRNP assembly. These results demonstrate that the ASO-tsRNA strategy provides insight into the trans-splicing mechanism and a means of significantly enhancing trans-splicing activity in vivo

General practice performance in referral for suspected cancer: influence of number of cases and case-mix on publicly reported data

Background:Publicly available data show variation in GPs’ use of urgent suspected cancer (USC) referral pathways. We investigated whether this could be due to small numbers of cancer cases and random case-mix, rather than due to true variation in performance. Methods:We analysed individual GP practice USC referral detection rates (proportion of the practice's cancer cases that are detected via USC) and conversion rates (proportion of the practice's USC referrals that prove to be cancer) in routinely collected data from GP practices in all of England (over 4 years) and northeast Scotland (over 7 years). We explored the effect of pooling data. We then modelled the effects of adding random case-mix to practice variation. Results:Correlations between practice detection rate and conversion rate became less positive when data were aggregated over several years. Adding random case-mix to between-practice variation indicated that the median proportion of poorly performing practices correctly identified after 25 cancer cases were examined was 20% (IQR 17 to 24) and after 100 cases was 44% (IQR 40 to 47). Conclusions:Much apparent variation in GPs’ use of suspected cancer referral pathways can be attributed to random case-mix. The methods currently used to assess the quality of GP-suspected cancer referral performance, and to compare individual practices, are misleading. These should no longer be used, and more appropriate and robust methods should be develope

The National Awareness and Early Diagnosis Initiative in England: assembling the evidence

A National Awareness and Early Diagnosis Initiative (NAEDI) has been established in England as part of the Government's strategy to improve cancer outcomes. One of the early priorities for this initiative has been to assemble the diverse evidence linking late diagnosis with poor survival and avoidable deaths. This supplement brings together new perspectives on existing research in this area together with findings from recently commissioned research. This paper describes a provisional model, the ‘NAEDI pathway', for testing hypotheses relating to late diagnosis and its impact. Key findings from other papers in this supplement are also highlighted

Knowledge or noise? Making sense of General Practitioners’ and Consultant use of two-week-wait referrals for suspected cancer

This work was funded by the National Awareness & Early Diagnosis Initiative. It was undertaken in the secure environment of the Northern Ireland Cancer Registry, which is funded by the Northern Ireland Public Health Agency. We are grateful to the staff in the Health & Social Care Board for their advice and guidance on this study.Peer reviewedPostprin