ORCID Profile
0000-0003-3053-8509
Current Organisations
University of South Australia
,
Centre for Cancer Biology
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Publisher: Springer Science and Business Media LLC
Date: 23-06-2016
DOI: 10.1007/S10456-016-9520-Y
Abstract: Desmogleins (DSG) are a family of cadherin adhesion proteins that were first identified in desmosomes and provide cardiomyocytes and epithelial cells with the junctional stability to tolerate mechanical stress. However, one member of this family, DSG2, is emerging as a protein with additional biological functions on a broader range of cells. Here we reveal that DSG2 is expressed by non-desmosome-forming human endothelial progenitor cells as well as their mature counterparts [endothelial cells (ECs)] in human tissue from healthy in iduals and cancer patients. Analysis of normal blood and bone marrow showed that DSG2 is also expressed by CD34(+)CD45(dim) hematopoietic progenitor cells. An inability to detect other desmosomal components, i.e., DSG1, DSG3 and desmocollin (DSC)2/3, on these cells supports a solitary role for DSG2 outside of desmosomes. Functionally, we show that CD34(+)CD45(dim)DSG2(+) progenitor cells are multi-potent and pro-angiogenic in vitro. Using a 'knockout-first' approach, we generated a Dsg2 loss-of-function strain of mice (Dsg2 (lo/lo)) and observed that, in response to reduced levels of Dsg2: (i) CD31(+) ECs in the pancreas are hypertrophic and exhibit altered morphology, (ii) bone marrow-derived endothelial colony formation is impaired, (iii) ex vivo vascular sprouting from aortic rings is reduced, and (iv) vessel formation in vitro and in vivo is attenuated. Finally, knockdown of DSG2 in a human bone marrow EC line reveals a reduction in an in vitro angiogenesis assay as well as relocalisation of actin and VE-cadherin away from the cell junctions, reduced cell-cell adhesion and increased invasive properties by these cells. In summary, we have identified DSG2 expression in distinct progenitor cell subpopulations and show that, independent from its classical function as a component of desmosomes, this cadherin also plays a critical role in the vasculature.
Publisher: The Company of Biologists
Date: 15-12-2020
DOI: 10.1242/JCS.247783
Abstract: The tissue microenvironment supports normal tissue function and regulates the behaviour of parenchymal cells. Tumour cell behaviour, on the other hand, erges significantly from that of their normal counterparts, rendering the microenvironment hostile to tumour cells. To overcome this problem, tumours can co-opt and remodel the microenvironment to facilitate their growth and spread. This involves modifying both the biochemistry and the biophysics of the normal microenvironment to produce a tumour microenvironment. In this Cell Science at a Glance article and accompanying poster, we outline the key processes by which epithelial tumours influence the establishment of the tumour microenvironment. As the microenvironment is populated by genetically normal cells, we discuss how controlling the microenvironment is both a significant challenge and a key vulnerability for tumours. Finally, we review how new insights into tumour–microenvironment interactions has led to the current consensus on how these processes may be targeted as novel anti-cancer therapies.
Publisher: Elsevier BV
Date: 04-2019
DOI: 10.1016/J.JRI.2019.01.002
Abstract: Endometriotic lesion development involves complex interactions between endometrial tissue, the peritoneum and immune cells. Macrophages are essential in this process however their precise roles are not defined. To investigate whether infiltrating macrophages acquire functionally different phenotypes during lesion development, human endometrial tissues were grafted into immunodeficient mice expressing macrophage-specific green fluorescent protein (GFP). Although the numbers of GFP-positive macrophages were similar in lesions 4, 7, 10 and 14 days after grafting, their surface markers changed over time. Inflammatory markers MHC class II (MHC II) and iNOS were present on 36% and 41% of macrophages respectively early in lesion development at day 4, whereas abundance of tissue remodelling markers peaked later, with arginase 1 most highly expressed on 57% of macrophages at day 7 and scavenger receptor A (CD204) on 66% of macrophages at day 14. This is consistent with a transition from classical M1 macrophage activity to an alternate M2 profile, which correlates to histological hallmarks of initially acute inflammation followed by tissue remodelling during lesion development. This progressive shift in phenotype is likely to be relevant to the mechanisms by which macrophages are central players in endometriosis-like lesion development.
Publisher: Elsevier BV
Date: 03-2012
DOI: 10.1016/J.AJPATH.2011.11.013
Abstract: Transforming growth factor-β1 (TGFB1) is a multifunctional cytokine that is abundant in both endometriotic lesions and the peritoneal fluid in women with endometriosis. However, the role of TGFB1 in the development of endometriosis is as yet undefined. In the present study, we investigated the physiologic function of TGFB1 in endometriotic lesion development, using Tgfb1-null mutant mice on a background of severe combined immunodeficiency. Xenotransplantation of human eutopic endometrial tissue resulted in development of endometriosis-like lesions in 63% of ovariectomized estrogen-supplemented Tgfb1-null mutant mice and in 68% of wild-type control mice. Median lesion weight was reduced by 11-fold in Tgfb1-null mice compared with wild-type control mice, and the fraction of glandular epithelium in lesions from Tgfb1-null mice was reduced by 32% compared with that in control mice. In lesions from Tgfb1-null mice, the relative abundance of both macrophages and α-smooth muscle actin-positive myofibroblasts was reduced by 66% and 47%, respectively. Deficiency of TGFB1 neither altered the percentage of proliferating cells in the epithelial or stromal compartments of the lesions nor affected blood vessel density or vessel size. Observation of this study indicates that host-derived TGFB1 deficiency suppresses endometriotic lesion development and provides proof of principle that targeting TGFB1 signaling pathways in cells that support the survival of ectopic endometrium may be an effective therapeutic approach in women with endometriosis.
Publisher: Impact Journals, LLC
Date: 22-06-2016
Publisher: Informa UK Limited
Date: 09-03-2022
Publisher: Wiley
Date: 24-07-2021
Abstract: Multiple myeloma (MM) is the second most common haematological malignancy and is an incurable disease of neoplastic plasma cells (PC). Newly diagnosed MM patients currently undergo lengthy genetic testing to match chromosomal mutations with the most potent drug/s to decelerate disease progression. With only 17% of MM patients surviving 10‐years postdiagnosis, faster detection and earlier intervention would unequivocally improve outcomes. Here, we show that the cell surface protein desmoglein‐2 (DSG2) is overexpressed in ~ 20% of bone marrow biopsies from newly diagnosed MM patients. Importantly, DSG2 expression was strongly predictive of poor clinical outcome, with patients expressing DSG2 above the 70 th percentile exhibiting an almost 3‐fold increased risk of death. As a prognostic factor, DSG2 is independent of genetic subtype as well as the routinely measured biomarkers of MM activity (e.g. paraprotein). Functional studies revealed a nonredundant role for DSG2 in adhesion of MM PC to endothelial cells. Together, our studies suggest DSG2 to be a potential cell surface biomarker that can be readily detected by flow cytometry to rapidly predict disease trajectory at the time of diagnosis.
Publisher: Portland Press Ltd.
Date: 17-12-2018
DOI: 10.1042/BST20180334
Abstract: Reciprocal biochemical and biophysical interactions between tumor cells, stromal cells and the extracellular matrix (ECM) result in a unique tumor microenvironment that determines disease outcome. The cellular component of the tumor microenvironment contributes to tumor growth by providing nutrients, assisting in the infiltration of immune cells and regulating the production and remodeling of the ECM. The ECM is a noncellular component of the tumor microenvironment and provides both physical and biochemical support to the tumor cells. Rho–ROCK signaling is a key regulator of actomyosin contractility and regulates cell shape, cytoskeletal arrangement and thereby cellular functions such as cell proliferation, differentiation, motility and adhesion. Rho–ROCK signaling has been shown to promote cancer cell growth, migration and invasion. However, it is becoming clear that this pathway also regulates key tumor-promoting properties of the cellular and noncellular components of the tumor microenvironment. There is accumulating evidence that Rho–ROCK signaling enhances ECM stiffness, modifies ECM composition, increases the motility of tumor-associated fibroblasts and lymphocytes and promotes trans-endothelial migration of tumor-associated lymphocytes. In this review, we briefly discuss the current state of knowledge on the role of Rho–ROCK signaling in regulating the tumor microenvironment and the implications of this knowledge for therapy, potentially via the development of selective inhibitors of the components of this pathway to permit the tuning of signaling flux, including one ex le with demonstrated utility in pre-clinical models.
Publisher: Springer Science and Business Media LLC
Date: 24-07-2018
DOI: 10.1038/S41467-018-05220-6
Abstract: The cellular and molecular basis of stromal cell recruitment, activation and crosstalk in carcinomas is poorly understood, limiting the development of targeted anti-stromal therapies. In mouse models of triple negative breast cancer (TNBC), Hedgehog ligand produced by neoplastic cells reprograms cancer-associated fibroblasts (CAFs) to provide a supportive niche for the acquisition of a chemo-resistant, cancer stem cell (CSC) phenotype via FGF5 expression and production of fibrillar collagen. Stromal treatment of patient-derived xenografts with smoothened inhibitors (SMOi) downregulates CSC markers expression and sensitizes tumors to docetaxel, leading to markedly improved survival and reduced metastatic burden. In the phase I clinical trial EDALINE, 3 of 12 patients with metastatic TNBC derived clinical benefit from combination therapy with the SMOi Sonidegib and docetaxel chemotherapy, with one patient experiencing a complete response. These studies identify Hedgehog signaling to CAFs as a novel mediator of CSC plasticity and an exciting new therapeutic target in TNBC.
No related grants have been discovered for Zahied Johan.