CCBIO Seminar - Ian Mackenzie

Welcome to the CCBIO Seminar series!

Time: Thursday April 26th 2018, at 14.30.

Place: Auditorium 4, BB-building, Jonas Lies vei 91, Bergen.

Speaker: Professor Ian Mackenzie from the Centre for Cell Biology and Cutaneous Research, the Blizard Institute, Queen Mary University of London.

Title: "Stem cell plasticity in head and neck cancers”

Chairperson: Anne Christine Johannessen

Professor Ian Mackenzie: Professor Ian Mackenzie trained at the London Hospital and at the Royal College of Surgeons, initially in Dentistry, then in Oral Surgery, and subsequently in Oral Pathology. He then moved to the USA for over twenty years, directing research institutes at the Universities of Iowa and Texas. Before returning to London, he was Vice Dean for Research at the University of Wales School of Medicine and Dentistry in Cardiff. During studies for his PhD he developed interests in the cellular mechanisms involved in the maintenance of skin and oral mucosa and these remain the basis of his continuing interests in stem cells, tissue renewal, and cancer. Prof. Ian Mackenzie has published a series of papers reporting the properties of cancer stem cells in head and neck cancers, including the roles of epithelial-mesenchymal transition in metastasis and therapy resistance, the roles of stromal cytokines and hypoxia in inducing EMT, changes of cell drug resistance associated with phenotypic plasticity, and the roles of CD44 in controlling cancer stem cell phenotypes.

email contact: i.c.mackenzie@qmul.ac.uk

Abstract:

The presence of stem cells in malignancies has several implications for diagnosis and therapy. Typically, malignant change originates in stem cells,, they are the drivers of tumour growth and, being more resistant resistant to chemo- and radio-therapies, they are responsible for tumour recurrence after therapy. As  "tumour initiating cells” they generate secondary growth but the mechanisms of their their translocation to distant metastatic sites are unclear. An "epithelial to mesenchymal transition” (EMT) has been widely proposed but, despite EMT-like changes at tumour margins, individual migrating EMT cells are difficult to identify in human tissues. A further reversible transition to an “amoeboid” cell type has now been studied. isolation and analysis of amoeboid cells indicates that they lack expression of markers typically used to identify EMT cells (e.g., keratins, ESA, e-cadherin, CD24) and this probably renders them “invisible”. However, some genes are found to be selectively expressed in amoeboid cells and staining for such gene products identifies cells in the stroma adjacent to human tumours. It appears that  stem cells  are present in at least three different forms  in HNSCC and that the plasticity of these cells markedly influences tumour properties and therapeutic responses.