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Large-scale human genetic data1-3 have shown that cancer mutations display strong tissue-selectivity, but how this selectivity arises remains unclear. Here, using experimental models, functional genomics and analyses of patient samples, we demonstrate that the lineage transcription factor paired box 8 (PAX8) is required for oncogenic signalling by two common genetic alterations that cause clear cell renal cell carcinoma (ccRCC) in humans: the germline variant rs7948643 at 11q13.3 and somatic inactivation of the von Hippel-Lindau tumour suppressor (VHL)4-6. VHL loss, which is observed in about 90% of ccRCCs, can lead to hypoxia-inducible factor 2α (HIF2A) stabilization6,7. We show that HIF2A is preferentially recruited to PAX8-bound transcriptional enhancers, including a pro-tumorigenic cyclin D1 (CCND1) enhancer that is controlled by PAX8 and HIF2A. The ccRCC-protective allele C at rs7948643 inhibits PAX8 binding at this enhancer and downstream activation of CCND1 expression. Co-option of a PAX8-dependent physiological programme that supports the proliferation of normal renal epithelial cells is also required for MYC expression from the ccRCC metastasis-associated amplicons at 8q21.3-q24.3 (ref. 8). These results demonstrate that transcriptional lineage factors are essential for oncogenic signalling and that they mediate tissue-specific cancer risk associated with somatic and inherited genetic variants., Medical Research Council (MC_UU_12022/7 and MC_UU_12022/10) and Kidney Research UK (RP_033_20170303).

BackgroundThe Golgi–Cox stain is an established method for characterising neuron cell morphology. The method highlights neurite processes of stained cells allowing the complexity of dendritic branching to be measured.New methodsConventional rapid Golgi and Golgi–Cox methods all require fresh impregnation in unfixed brain blocks. Here, we describe a modified method that gives high quality staining on brain tissue blocks perfusion-fixed with 4% paraformaldehyde (PFA) and post-fixed by immersion for 24h.ResultsTissue perfused with 4% PFA and post fixed for 24h remained viable for the modified Golgi–Cox silver impregnation staining of mouse striatum from perfused wild type and zQ175. It was not found necessary to impregnate tissue blocks with Golgi solutions prior to sectioning, as post-sectioned tissues yielded equally good impregnation. Impregnation for 14 days resulted in optimal visualisation of striatal neuron and dendritic morphology. Although no modifications applied to the rapid Golgi method were reliable, the modified Golgi–Cox method yielded consistently reliable high-quality staining.Comparison with existing methodsThe current method used fixed tissues to reduce damage and preserve cell morphology. The revised method was found to be fast, reliable and cost effective without the need for expensive staining kits and could be performed in any neuroscience lab with limited specialist equipment.ConclusionsThe present study introduces a robust reproducible and inexpensive staining method for identifying neuronal morphological changes in the post fixed mouse brain, and is suitable for assessing changes in cell morphology in models of neurodegeneration and in response to experimental treatment.

Wegener's Granulomatosis, classically, comprises a triad of granulomatous vasculitis in the upper and lower respiratory tracts, and a focal and segmental, necrotising glomerulonephritis in the kidney. In practice disease presentation and organ involvement is widespread and variable. The aetiology is unknown but an infectious aetiology has been proposed, based on the especial involvement of the respiratory tract in the disease process. The pathogenesis is also unclear but immune complex deposition leading to neutrophil chemotaxis and activation causing endothelial injury has been suggested. Recently antibodies against a component of neutrophil cytoplasm have been described in Wegener's Granulomatosis. This thesis records studies of the diagnosis and pathogenesis of Wegener's Granulomatosis. The first part of the study examined the problem of diagnosis using renal biopsy material. Renal biopsy is important because renal functional status is the major factor determining outcome, yet renal biopsy appearances are not specific for the condition and may be found in other vasculitides such as microscopic polyarteritis. Review of the histology, immunofluorescence studies and ultrastructure of renal biopsies from patients with Wegener's Granulomatosis and microscopic polyarteritis revealed no diagnostically useful differences. In Wegener's Granulomatosis renal mast cells were frequently present unassociated with areas of active inflammation, whereas in microscopic polyarteritis they were predominantly present as part of an inflammatory infiltrate. In both conditions the number of mast cells was increased. The functional significance of this difference is unclear. The second part of the study examined the presence of autoantibodies against neutrophils. IgG antibodies giving coarse, granular, cytoplasmic fluorescence when incubated with cytospin preparations of normal neutrophils were found to be highly specific for Wegener's Granulomatosis. Diffuse cytoplasmic fluorescence was present in a wide variety of other diseases including some other forms of systemic vasculitis. By differential protein extraction of neutrophils and Western Blot analysis IgG antibodies which gave coarse fluorescence were found to react with 4 5 kDa and 27-31 kDa proteins in the membrane-bound protein extract. This is consistent with the autoantibodies being directed against a component of neutrophil granules. An hypothesis is proposed. Wegener's Granulomatosis is the product of an immunological response to an antigen, possibly to an inhaled, exogenous pathogen. A predominantly cell-mediated response results in the typical lesions identified pathologically within the respiratory tract including granulomata. A humoral response also may ii occur, reflected by the presence of specific autoantibodies and this can lead to systemic injury primarily by the formation and deposition of immune complexes. In other systemic vasculitides, such as microscopic polyarteritis, a variety of exogenous antigens result in humoral responses and immune complex formation and deposition leading to the same pattern of renal injury.