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https://hdl.handle.net/2440/136844
2024-03-29T10:13:09ZUltrastructural analysis of prostate cancer tissue provides insights into androgen-dependent adaptations to membrane contact site establishment
https://hdl.handle.net/2440/140063
Title: Ultrastructural analysis of prostate cancer tissue provides insights into androgen-dependent adaptations to membrane contact site establishment
Author: Butler, L.M.; Evergren, E.
Abstract: Membrane trafficking and organelle contact sites are important for regulating cell metabolism and survival; processes often deregulated in cancer. Prostate cancer is the second leading cause of cancer-related death in men in the developed world. While early-stage disease is curable by surgery or radiotherapy there is an unmet need to identify prognostic biomarkers, markers to treatment response and new therapeutic targets in intermediate-late stage disease. This study explored the morphology of organelles and membrane contact sites in tumor tissue from normal, low and intermediate histological grade groups. The morphology of organelles in secretory prostate epithelial cells; including Golgi apparatus, ER, lysosomes; was similar in prostate tissue samples across a range of Gleason scores. Mitochondrial morphology was not dramatically altered, but the number of membrane contacts with the ER notably increased with disease progression. A three-fold increase of tight mitochondria-ER membrane contact sites was observed in the intermediate Gleason score group compared to normal tissue. To investigate whether these changes were concurrent with an increased androgen signaling in the tissue, we investigated whether an anti-androgen used in the clinic to treat advanced prostate cancer (enzalutamide) could reverse the phenotype. Patient-derived explant tissues with an intermediate Gleason score were cultured ex vivo in the presence or absence of enzalutamide and the number of ER-mitochondria contacts were quantified for each matched pair of tissues. Enzalutamide treated tissue showed a significant reduction in the number and length of mitochondria-ER contact sites, suggesting a novel androgen-dependent regulation of these membrane contact sites. This study provides evidence for the first time that prostate epithelial cells undergo adaptations in membrane contact sites between mitochondria and the ER during prostate cancer progression. These adaptations are androgen-dependent and provide evidence for a novel hormone-regulated mechanism that support establishment and extension of MAMs. Future studies will determine whether these changes are required to maintain pro-proliferative signaling and metabolic changes that support prostate cancer cell viability.
Description: PUBLISHED 17 July 20232023-01-01T00:00:00ZTargeting hyaluronan-mediated motility receptor (HMMR) enhances response to androgen receptor signalling inhibitors in prostate cancer
https://hdl.handle.net/2440/140014
Title: Targeting hyaluronan-mediated motility receptor (HMMR) enhances response to androgen receptor signalling inhibitors in prostate cancer
Author: Hinneh, J.A.; Gillis, J.L.; Mah, C.Y.; Irani, S.; Shrestha, R.K.; Ryan, N.K.; Atsushi, E.; Nassar, Z.D.; Lynn, D.J.; Selth, L.A.; Kato, M.; Centenera, M.M.; Butler, L.M.
Abstract: BACKGROUND: Resistance to androgen receptor signalling inhibitors (ARSIs) represents a major clinical challenge in prostate cancer. We previously demonstrated that the ARSI enzalutamide inhibits only a subset of all AR-regulated genes, and hypothesise that the unaffected gene networks represent potential targets for therapeutic intervention. This study identified the hyaluronan-mediated motility receptor (HMMR) as a survival factor in prostate cancer and investigated its potential as a co-target for overcoming resistance to ARSIs. METHODS: RNA-seq, RT-qPCR and Western Blot were used to evaluate the regulation of HMMR by AR and ARSIs. HMMR inhibition was achieved via siRNA knockdown or pharmacological inhibition using 4-methylumbelliferone (4-MU) in prostate cancer cell lines, a mouse xenograft model and patient-derived explants (PDEs). RESULTS: HMMR was an AR-regulated factor that was unaffected by ARSIs. Genetic (siRNA) or pharmacological (4-MU) inhibition of HMMR significantly suppressed growth and induced apoptosis in hormone-sensitive and enzalutamide-resistant models of prostate cancer. Mechanistically, 4-MU inhibited AR nuclear translocation, AR protein expression and subsequent downstream AR signalling. 4-MU enhanced the growth-suppressive effects of 3 different ARSIs in vitro and, in combination with enzalutamide, restricted proliferation of prostate cancer cells in vivo and in PDEs. CONCLUSION: Co-targeting HMMR and AR represents an effective strategy for improving response to ARSIs.
Description: Published online: 6 September 20232023-01-01T00:00:00ZInterplay between the EMT transcription factors ZEB1 and ZEB2 regulates hematopoietic stem and progenitor cell differentiation and hematopoietic lineage fidelity
https://hdl.handle.net/2440/138917
Title: Interplay between the EMT transcription factors ZEB1 and ZEB2 regulates hematopoietic stem and progenitor cell differentiation and hematopoietic lineage fidelity
Author: Wang, J.; Farkas, C.; Benyoucef, A.; Carmichael, C.; Haigh, K.; Wong, N.; Huylebroeck, D.; Stemmler, M.P.; Brabletz, S.; Brabletz, T.; Nefzger, C.M.; Goossens, S.; Berx, G.; Polo, J.M.; Haigh, J.J.
Editor: Eaves, C.J.
Abstract: The ZEB2 transcription factor has been demonstrated to play important roles in hematopoiesis and leukemic transformation. ZEB1 is a close family member of ZEB2 but has remained more enigmatic concerning its roles in hematopoiesis. Here, we show using conditional loss-of-function approaches and bone marrow (BM) reconstitution experiments that ZEB1 plays a cell-autonomous role in hematopoietic lineage differentiation, particularly as a positive regulator of monocyte development in addition to its previously reported important role in T-cell differentiation. Analysis of existing single-cell (sc) RNA sequencing (RNA-seq) data of early hematopoiesis has revealed distinctive expression differences between Zeb1 and Zeb2 in hematopoietic stem and progenitor cell (HSPC) differentiation, with Zeb2 being more highly and broadly expressed than Zeb1 except at a key transition point (short-term HSC [ST-HSC]➔MPP1), whereby Zeb1 appears to be the dominantly expressed family member. Inducible genetic inactivation of both Zeb1 and Zeb2 using a tamoxifen-inducible Cre-mediated approach leads to acute BM failure at this transition point with increased long-term and short-term hematopoietic stem cell numbers and an accompanying decrease in all hematopoietic lineage differentiation. Bioinformatics analysis of RNA-seq data has revealed that ZEB2 acts predominantly as a transcriptional repressor involved in restraining mature hematopoietic lineage gene expression programs from being expressed too early in HSPCs. ZEB1 appears to fine-tune this repressive role during hematopoiesis to ensure hematopoietic lineage fidelity. Analysis of Rosa26 locus-based transgenic models has revealed that Zeb1 as well as Zeb2 cDNA-based overexpression within the hematopoietic system can drive extramedullary hematopoiesis/splenomegaly and enhance monocyte development. Finally, inactivation of Zeb2 alone or Zeb1/2 together was found to enhance survival in secondary MLL-AF9 acute myeloid leukemia (AML) models attesting to the oncogenic role of ZEB1/2 in AML.
Description: Published: September 22, 20212021-01-01T00:00:00ZCytotoxicity-related gene expression and chromatin accessibility define a subset of CD4+ T cells that mark progression to type 1 diabetes.
https://hdl.handle.net/2440/137004
Title: Cytotoxicity-related gene expression and chromatin accessibility define a subset of CD4+ T cells that mark progression to type 1 diabetes.
Author: Bediaga, N.G.; Garnham, A.L.; Naselli, G.; Bandala-Sanchez, E.; Stone, N.L.; Cobb, J.; Harbison, J.E.; Wentworth, J.M.; Ziegler, A.G.; Couper, J.J.; Smyth, G.K.; Harrison, L.C.
Abstract: Type 1 diabetes in children is heralded by a preclinical phase defined by circulating autoantibodies to pancreatic islet antigens. How islet autoimmunity is initiated and then progresses to clinical diabetes remains poorly understood. Only one study has reported gene expression in specific immune cells of children at risk associated with progression to islet autoimmunity. We analyzed gene expression with RNA sequencing in CD4+ and CD8+ T cells, natural killer (NK) cells, and B cells, and chromatin accessibility by assay for transposase-accessible chromatin sequencing (ATAC-seq) in CD4+ T cells, in five genetically at risk children with islet autoantibodies who progressed to diabetes over a median of 3 years (“progressors”) compared with five children matched for sex, age, and HLA-DR who had not progressed (“nonprogressors”). In progressors, differentially expressed genes (DEGs) were largely confined to CD4+ T cells and enriched for cytotoxicity-related genes/pathways. Several top-ranked DEGs were validated in a semi-independent cohort of 13 progressors and 11 nonprogressors. Flow cytometry confirmed that progression was associated with expansion of CD4+ cells with a cytotoxic phenotype. By ATAC-seq, progression was associated with reconfiguration of regulatory chromatin regions in CD4+ cells, some linked to differentially expressed cytotoxicity-related genes. Our findings suggest that cytotoxic CD4+ T cells play a role in promoting progression to type 1 diabetes.
Description: This article contains supplementary material online at https://doi.org/10.2337/figshare.17185898.2022-01-01T00:00:00Z