ORCID Profile
0000-0002-8523-0715
Current Organisation
University of Tasmania
Does something not look right? The information on this page has been harvested from data sources that may not be up to date. We continue to work with information providers to improve coverage and quality. To report an issue, use the Feedback Form.
Publisher: MDPI AG
Date: 05-11-2020
DOI: 10.3390/PH13110368
Abstract: Medulloblastoma (MB) is the most common malignant childhood brain cancer. High-risk MB tumours have a high incidence of metastasis and result in poor patient survival. Drug screens, commonly used to identify potential novel therapeutic agents against MB, focus on 2D cell proliferation and viability assays given that these assays are easily adaptable to high-throughput regimes. However, 2D models fail to address invasive characteristics that are crucial to MB metastasis and are thus not representative of tumour growth in vivo. In this study, we developed a 3D 384-well agar colony formation assay using MB cells of molecular subgroup 3 that is associated with the highest level of metastasis. Two fluorescence substrates, resazurin and glycyl-phenylalanyl-aminofluorocoumarin (GF-AFC) that measure cell viability via distinct mechanisms were used to assess the growth of MB cells in the agar matrix. The assay was optimised for seeding density, growth period, substrate incubation time and homogeneity of the fluorescent signals within in idual wells. Our data demonstrate the feasibility to multiplex the two fluorescent substrates without detectable signal interference. This assay was validated by assessing the concentration-dependent effect of two commonly used chemotherapeutic agents clinically used for MB treatment, vincristine and lomustine. Subsequently, a panel of plasma membrane calcium channel modulators was screened for their effect on the 3D growth of D341 MB cells, which identified modulators of T-type voltage gated and ORAI calcium channels as selective growth modulators. Overall, this 3D assay provides a reproducible, time and cost-effective assay for high-throughput screening to identify potential drugs against MB.
Publisher: Authorea, Inc.
Date: 05-10-2023
Publisher: MDPI AG
Date: 27-08-2021
Abstract: Dysregulation in calcium signalling is implicated in several cancer-associated processes, including cell proliferation, migration, invasion and therapy resistance. Modulators of specific calcium-regulating proteins have been proposed as promising future therapeutic agents for some cancers. Alterations in calcium signalling have been extensively studied in some cancers however, this area of research is highly underexplored in medulloblastoma (MB), the most common paediatric malignant brain tumour. Current MB treatment modalities are not completely effective and can result in several long-lasting mental complications. Hence, new treatment strategies are needed. In this study, we sought to probe the landscape of calcium signalling regulators to uncover those most likely to be involved in MB tumours. We investigated the expression of calcium signalling regulator genes in MB patients using publicly available datasets. We stratified the expression level of these genes with MB molecular subgroups, tumour metastasis and patient survival to uncover correlations with clinical features. Of particular interest was CACNA1 genes, in which we were able to show a developmentally-driven change in expression within the cerebellum, MB’s tissue of origin, highlighting a potential influence on tumour incidence. This study lays a platform for future investigations into molecular regulators of calcium signalling in MB formation and progression.
Publisher: MDPI AG
Date: 26-01-2019
Abstract: Calcium signaling, in addition to its numerous physiological roles, is also implicated in several pathological conditions including cancer. An increasing body of evidence suggest critical roles of calcium signaling in the promotion of different aspects of cancer, including cell proliferation, therapy resistance and metastatic-related processes. In many cases, this is associated with altered expression and/or activity of some calcium channels and pumps. Brain cancers have also been the subject of many of these studies. In addition to erse roles of calcium signals in normal brain function, a number of proteins involved in calcium transport are implicated to have specific roles in some brain cancers including gliomas, medulloblastoma, neuroblastoma and meningioma. This review discusses research that has been conducted so far to understand erse roles of Ca2+-transporting proteins in the progression of brain cancers, as well as any attempts to target these proteins towards a therapeutic approach for the control of brain cancers. Finally, some knowledge gaps in the field that may need to be further considered are also discussed.
No related grants have been discovered for Ahmed Maklad.