The Caspase Laboratory is a research group led by Dr Howard Fearnhead and is a part of the Apoptosis Cluster. The Laboratory investigates the role of caspase activation in cancer cell apoptosis.
Programmed cell death or apoptosis is of fundamental importance to cancer as it both limits tumorigenesis and is also triggered by many cancer chemotherapeutics. Importantly, cancer cells often acquire mutations that compromise the apoptotic process, allowing these cells both to escape normal growth constraints and to become resistant to many anti-cancer drugs, resulting in the emergence of drug-resistant malignancies. Thus discovering how apoptosis is regulated and why it fails in cancer is central both to understanding cancer progression and developing new therapies to counter chemo-resistant cancers.
Much cancer research is focussed on a molecular understanding of cancer cell biology with the aim of developing tailored therapies that are designed to target tumours displaying specific molecular lesions. The power of this approach for treating breast cancer is demonstrated by Trastuzumab and anti-estrogen therapies, designed to target tumours that are HER2 or ER positive respectively. Despite the success of these targeted treatments for a subset of patients, many other patients do not benefit and efforts to identify new therapies to either complement or replace existing chemotherapy continue. The difficulty is that the estimated time and cost of discovering and developing a new drug is ~15 years and hundreds of millions of dollars. The time involved means many will die before a therapy becomes available whilst the high development cost increases the cost of the therapy and can render it unaffordable for many.Repurposing existing drugs for new uses provides an approach that can address both problems. Repurposing is attractive as a wealth of preclinical and clinical data are already available, greatly reducing the time and money required to bring a candidate to clinical trial. This accelerated development translates into better, cheaper patient care, faster. We have therefore been screening the Johns Hopkins Clinical Compound Library of ~1,400 approved compounds using drug-resistant breast cancer cells and the Core Screening Laboratory at NUI Galway.
Not all caspases are involved in apoptosis; caspases-1, -4 and -5 are involved in inflammatory responses where they are important for the proteolytic maturation of cytokines. The specificity of caspases for a particular process is defined by the selective cleavage of substrate; inflammatory caspases preferentially bind and cleave cytokines, while apoptotic caspases cleave a different set of proteins. It is therefore remarkable that the apoptotic effector caspase, caspase-3 is not only required for the differentiation of muscle progenitor cells into myofibers but apparently is sufficient for this differentiation.
TPCK-induced apoptosis and labelling of the largest subunit of RNA polymerase II in Jurkat cells. Fabian Z, O'Brien P, Pajęcka K, Fearnhead HO. Apoptosis 2009 Oct;14(10):1154-64.
TPCK targets elements of mitotic spindle and induces cell cycle arrest in prometaphase. Fabian Z, Fearnhead HO. Biochem Biophys Res Commun. 2010 May 14;395(4):458-64.
Genomic approaches have been employed to compare gene expression profiles in normal and cancer cells, but these expression patterns do not allow good discrimination between the two cell types. More recently, the patterns of microRNA expression in normal and cancer cells have been compared and observed to differentiate between non-tumour cell and tumour cell. Subsequently, specific miRNAs were found to correlate with the stage of breast cancer. Moreover, some of these miRNAs regulate genes that control cancer cell proliferation and survival, providing a mechanistic underpinning for the correlative studies.
The strategy is to use clinical cancer samples in a genomics-based approach to identify miRNAs associated with aspects of cancer biology. More specifically to identify miRNAs associated with tumour stage and grade, with sensitivity or resistance to particular treatments or with a particular prognosis. The identification of these miRNAs will drive both basic research through collaborations inside and outside of NUIG and also translational research aimed at developing diagnostic tools for cancer. The Breast Cancer Research group headed by Professor of Surgery, Michael Kerins, maintains The Breast Cancer Tissue Bank. This consists of matched non-tumour and tumour frozen tissue specimens from 200 patients and the associated detailed clinical histories. This tissue bank and the accompanying clinical histories is an enormously valuable, and so far untapped, resource for Breast cancer research.
Intracellular Nucleotides Act as Critical Prosurvival Factors by Binding to Cytochrome C and Inhibiting Apoptosome (2006) Dhyan Chandra, Shawn B. Bratton, Maria D. Person, Yanan Tian, Angel G. Martin, Mary Ayres, Howard O.Fearnhead, Varsha Gandhi, and Dean G. Tang Cell, Vol 125, 1333-1346.
Small molecule inhibitors of Apaf-1-related caspase- 3/-9 activation that control mitochondrial-dependent apoptosis. (2005) Malet G, Martin AG, Orzaez M, Vicent MJ, Masip I, Sanclimens G, Ferrer-Montiel A, Mingarro I, Messeguer A, Fearnhead HO, Perez-Paya E. Cell Death Differ. Dec 9.
Apo cytochrome c inhibits caspases by preventing apoptosome formation. (2004) Angel G. Martin, Jack Nguyen, Jim Wells and Howard O. Fearnhead. Biochem. Biophys. Res. Commun. 2;319(3):944-50
Getting Back on Track, or What to Do When Apoptosis Is De-Railed: Recoupling Oncogenes to the Apoptotic Machinery. (2004) Howard O. Fearnhead. Cancer Biol Ther. Jan;3(1):21-8. Review
Molecular Cloning of ILP-2, a novel member of the Inhibitor of Apoptosis Protein family (2001) B.W.M Richter, S.S. Mir, L.J. Eiben, J. Lewis, S. Berkey Reffey, A. Frattini, L. Tian, S. Frank, R. J. Youle, D. L. Nelson, L. D. Notarangelo, P. Vezzoni, H.O. Fearnhead and C. S. Duckett. Mol. Cell Biol. 13 4292-4301.
Cell-free systems to study apoptosis (2001) H O. Fearnhead. In Methods in Cell Biology (L Schwartz and J Ashwell, Eds). Academic Press, San Diego. 66 167-185.
Oncogene-dependent caspase activation is mediated by caspase-9 (1998) H. O.Fearnhead, J. Rodriguez, E. Govek, W. Guo, R. Kobayashi, G. Hannon and Y. A. Lazebnik. Proc. Natl. Acad. Sci. USA 95 13664-13669.
Oncogene-dependent apoptosis in extracts from drug-resistant cells. (1997) H.O. Fearnhead, M.E. McCurrach, J. O'Neill, K. Zhang, S.W. Lowe and Y.A. Lazebnik. Genes and Development 11 1266-1276.
Multiple species of CPP32 and Mch2 are the major active caspases present in apoptotic cells. (1997) L. Faleiro, R. Kobayashi, H.O. Fearnhead and Y.A. Lazebnik. EMBO J. 16 2271-2281.
A pre-existing protease is a common effector of thymocyte apoptosis mediated by diverse stimuli. (1995) H.O. Fearnhead, A.J. Rivett, D. Dinsdale and G.M. Cohen FEBS Lett. 357 242-246.
DNA degradation and proteolysis in thymocyte apoptosis. (1995) H.O. Fearnhead, M. MacFarlane, D. Dinsdale and G.M. Cohen Toxicology Lett. 82-83 135-141.
An interleukin-1 beta-converting enzyme-like protease is a common mediator of apoptosis in thymocytes. (1995) H. O. Fearnhead, D. Dinsdale, G.M. Cohen. FEBS Lett 375 283-288.
An ICE-like protease is a common mediator of apoptosis induced by diverse stimuli in human monocytic THP.1 cells. (1995) H. Zhu, H.O. Fearnhead, G.M. Cohen FEBS Lett 374 303-308.
Mechanisms of Cell Death, with Particular Reference to Apoptosis. (1995) Gerald M. Cohen, Marion MacFarlane, Howard, O. Fearnhead, Xiao-ming Sun and David Dinsdale. In Molecular and Cellular Mechanisms of Toxicity ( F. deMatteis and L.L. Smith, Eds). CRC Press, Boca Raton.
Dexamethasone and etoposide induce apoptosis in rat thymocytes from different phases of the cell cycle. (1994) H.O. Fearnhead, M. Chwalinski, R.T. Snowden, M.G. Ormerod, G.M. Cohen. Biochem Pharmacol 48 1073-1079.
Formation of large molecular weight fragments of DNA is a key committed step of apoptosis in thymocytes. (1994) Cohen G.M, X.M.Sun, H. O. Fearnhead, M. MacFarlane, D.G. Brown, R.T. Snowden, D. Dinsdale J Immunol 153 507-516.
- Professor Michael Kerin, Department of Surgery, NUI, Galway
- Professor Frank Giles, Clinical Research Facility, NUI Galway
- Professor Laurence Egan, Pharmacology and Therapeutics, NUI Galway
- Dr Grace McCormack, Zoology, NUI Galway
- Dr Timothy Gant, MRC Toxicology Unit, University of Leicester, UK
In 1991 Dr Fearnhead completed a BSc. in Pharmacology and Toxicology at the London School of Pharmacy, before being awarded a PhD. in 1995 by the University of Leicester for work perfomed at the MRC-Toxicology Centre. From '95 to '99 Dr Fearnhead was a post-doctoral fellow at Cold Spring Harbor Laboratory, NY before moving to the National Cancer Institute in Maryland as a principal investigator. In 2004 Dr Fearnhead moved to the National Centre of Biomedical Engineering Science (NCBES), National University of Ireland, Galway and in 2006 was appointed a lecturer in Pharmacology and Therapeutics (http://www.nuigalway.ie/pharmacology).
|Mail:||Room 213 NCBES,
|Telephone:||(+353) 91 495240|
|Fax:||(+353) 91 494596|
- Apoptosis Assays
- Protease assays with purified recombinant caspases
- Differentiation Assays
- Stock Solutions
- Cell Culture
- Extracts for cell-free caspase activation
- Assay for XIAP E3 ligase activity
- Recombinant Apaf-1 XL production & assays
- SDS-PAGE loading buffer
- MTT Assay