Several studies have demonstrated that sphingosine kinase 1 (SphK1) translocates to the plasma membrane (PM) upon its activation and further suggested the plasma membrane lipid raft microdomain (PMLRM) as a target for SphK1 relocalization. To date, however, direct evidence of SphK1 localization to the PMLRM has been lacking. In this report, using multiple biochemical and subcellular fractionation techniques we demonstrate that endogenous SphK1 protein and its substrate, D-erythro sphingosine, are present within the PMLRM. Additionally, we demonstrate that the PMA stimulation of SphK1 localized to the PMLRM results in production of sphingosine-1-phosphate as well as induction of cell growth under serum-deprivation conditions. We further report that Ser225Ala and Thr54Cys mutations, reported to abrogate phosphatidylserine binding, block SphK1 targeting to the PMLRM and SphK1 induced cell growth. Together these findings provide direct evidence that the PMLRM is the major site-of-action for SphK1 to overcome serum-deprived cell growth inhibition.

Sphingosine kinase 1 (SphK1) is an oncoprotein capable of directly transforming cells and is associated with resistance to chemotherapy and radiotherapy. SphK1 is increased in various human cancers; whereas, blockade restores sensitivity to therapeutic killing in chemotherapy resistant cancer cell lines. We investigated SphK1 expression in clinical tissue samples from patients with non-Hodgkin lymphomas (NHL). Tissues from 69 patients with either NHL (n = 44) or reactive lymphoid hyperplasias (RH) (n = 25) were examined for expression of SphK1 protein by Western blot and immunohistochemistry (IHC), and SphK1 and SphK2 mRNA by quantitative real-time reverse transcriptase polymerase chain reaction. SphK1 protein (p = 0.008) and mRNA (p = 0.035) levels were higher in NHL than RH, with a clear trend toward increasing levels with increasing clinical grade (p = 0.005 for SphK1 protein, p = 0.035 for IHC score and p = 0.002 for SphK1 mRNA). IHC generally confirmed protein signal in neoplastic cells, but some lymphomas exhibited staining in non-neoplastic cells. SphK1 is overexpressed in NHL and increases with increasing clinical grade. These results, combined with prior mechanistic studies suggest that SphK1 is an attractive novel target for pharmacological interventions for NHL.

IntroductionThe introduction of biological and synthetic meshes has revolutionised the practice of implant-based breast reconstruction (IBBR) but evidence for effectiveness is lacking. The iBRA (implant Breast Reconstruction evAluation) study is a national trainee-led project that aims to explore the practice and outcomes of IBBR to inform the design of a future trial. We report the results of the iBRA National Practice Questionnaire (NPQ) which aimed to comprehensively describe the provision and practice of IBBR across the UK.MethodsA questionnaire investigating local practice and service provision of IBBR developed by the iBRA Steering Group was completed by trainee and consultant leads at breast and plastic surgical units across the UK. Summary data for each survey item were calculated and variation between centres and overall provision of care examined.Results81 units within 79 NHS-hospitals completed the questionnaire. Units offered a range of reconstructive techniques, with IBBR accounting for 70% (IQR:50–80%) of participating units' immediate procedures. Units on average were staffed by 2.5 breast surgeons (IQR:2.0–3.0) and 2.0 plastic surgeons (IQR:1.0–3.0) performing 35 IBBR cases per year (IQR:20-50). Variation was demonstrated in the provision of novel different techniques for IBBR especially the use of biological (n = 62) and synthetic (n = 25) meshes and in patient selection for these procedures.ConclusionsThe iBRA-NPQ has demonstrated marked variation in the provision and practice of IBBR in the UK. The prospective audit phase of the iBRA study will determine the safety and effectiveness of different approaches to IBBR and allow evidence-based best practice to be explored.

Background Biological and synthetic meshes may improve the outcomes of immediate implant-based breast reconstruction (IBBR) by facilitating single-stage procedures and improving cosmesis. Supporting evidence is, however, limited. The aim of this study was to explore the impact of biological and synthetic mesh on patient-reported outcomes (PROs) of IBBR 18 months after surgery. Methods Consecutive women undergoing immediate IBBR between February 2014 and June 2016 were recruited to the study. Demographic, operative, oncological and 3-month complication data were collected, and patients received validated BREAST-Q questionnaires at 18 months. The impact of different IBBR techniques on PROs were explored using mixed-effects regression models adjusted for clinically relevant confounders, and including a random effect to account for clustering by centre. Results A total of 1470 participants consented to receive the questionnaire and 891 completed it. Of these, 67 women underwent two-stage submuscular reconstructions. Some 764 patients had a submuscular reconstruction with biological mesh (495 women), synthetic mesh (95) or dermal sling (174). Fourteen patients had a prepectoral reconstruction. Compared with two-stage submuscular reconstructions, no significant differences in PROs were seen in biological or synthetic mesh-assisted or dermal sling procedures. However, patients undergoing prepectoral IBBR reported better satisfaction with breasts (adjusted mean difference +6.63, 95 per cent c.i. 1.65 to11.61; P = 0.009). PROs were similar to those in the National Mastectomy and Breast Reconstruction Audit 2008–2009 cohort, which included two-stage submuscular procedures only. Conclusion This study found no difference in PROs of subpectoral IBBR with or without biological or synthetic mesh, but provides early data to suggest improved satisfaction with breasts following prepectoral reconstruction. Robust evaluation is required before this approach can be adopted as standard practice.