Cell signalling


Student project opportunities

 

Signalling networks in the regulation of red blood cell integrity and survival

Research area:  Blood cell signalling
Chief supervisor:  Associate Professor Evan Ingley
Other supervisors:  Professor Wendy Erber
Project suitable for:  PhD
Essential qualifications:  BSc Hons

Project outline

Red blood cells (RBCs, erythrocytes) are essential for transport and exchange of O2/CO2 around the body. Aberrant erythropoiesis may be a result of reduced production, which manifests as anaemia (insufficient RBCs), excess production leading to polycythaemia (excess RBCs), or ineffective production (dyserythropoiesis) leading to structurally and functionally abnormal red cells and anaemia. In situations of symptomatic anaemia, be it due to reduced or ineffective production, or following uncontrolled blood loss (e.g. secondary to trauma, surgery, bone marrow failure), RBC transfusion is required1. Stored blood for transfusion is not the same as that in the circulation. Blood may be stored for up to 42 days at 4oC which results in a “storage lesion” that impacts on the RBC function and lifespan following transfusion. This can lead to failure to alleviate the symptoms of anaemia and untoward clinical effects from iron and pro-inflammatory mediators released by compromised RBCs. The precise mechanisms for this are poorly understood. The cost and complications from the RBC storage lesion place a considerable health and economic burden on society. The CIs, who were the first to establish the importance of the signalling molecule Lyn (a Src family tyrosine kinase) in erythroid cells and mature RBCs, postulate that abnormalities in Lyn may occur during red cell storage. Lyn is a key kinase that phosphorylates the major membrane-cytoskeleton anchor Band3 that regulates metabolism, membrane transport and shape, which are essential for RBC integrity.

Hypotheses

(i) Signalling pathways involving Lyn play critical kinase-dependent and independent roles in RBCs, regulating integrity, response to stress (physical, osmotic, oxidative), and survival.
(ii) Targeting and perturbing essential signalling pathways will have clinical applications for RBC abnormalities and disorders, and the critical issue surrounding RBC storage and transfusion.

Aims

1. Fully characterise the contribution of signalling networks involving Lyn to RBC longevity, deformability, responses to stress (in vitro and in vivo), during RBC storage and transfusion in mice, as well as its importance for human RBCs (in vitro) for the RBC storage lesion.
2. Delineate central RBC biochemical/signalling networks and cellular biological consequences of manipulation of Lyn levels and kinase activity.
3. Assess the capacity of agents targeting Lyn and Src family kinases as therapies for ameliorating RBC pathologies associated with altered Lyn levels and activity.

Contact
Associate Professor Evan Ingley - Evan.ingley@perkins.uwa.edu.au

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Control of bone cancer cell migration and invasion by the scaffold protein AFAP1L1

Research area:  cancer cell signalling
Chief supervisor:  Associate Professor Evan Ingley
Project suitable for:  PhD
Essential qualifications:  BSc Hons

Project outline

Osteosarcoma (OS) is the most prevalent primary bone tumour. It is prominent in adolescents and young adults, being the 5th leading cause of cancer death in this age group. OS also has an incidence peak in people over 50 years of age. The current optimal therapy for OS involves high dose cytotoxic drugs and surgical resection. This has led to improved prognosis over the last 40 years with sustained overall survival rates approaching 70% for patients with localised (non-metastatic) cancer at diagnosis. However, up to 20% of patients present with metastatic disease and the majority of recurrences after therapy for local disease are also metastatic. Recently we identified a new and important regulator of OS cell migration and invasion AFAP1L1 (Actin Filament Associating Protein-1-Like-1) that shows strong association with metastatic disease. We detailed the molecular pathway that AFAP1L1 mediates at the cellular level3 to promote OS cell migration and invasion, critical aspects of metastatic disease, through specialized subcellular protrusions called invadopodia. These are actin-rich structures facilitate delivery of metalloproteases to mediate extracellular matrix (ECM) degradation, thereby promoting cancer cell migration and invasion, processes intrinsic to metastatic spread. AFAP1L1 is a scaffold protein that both provides direct links between the multiple critical pathways that govern invadopodia function, and receives inputs from growth factors and integrins, to regulate cytoskeletal components of the invadopodia.

Hypotheses

1. AFAP1L1 plays a critical, direct role in OS metastasis by acting as a scaffold facilitating invadopodia-driven cell migration, invasion and dissemination.
2. AFAP1L1 expression and/or phosphorylation status is a marker of OS metastasis and can potentially be used as a diagnostic indicator of malignant OS development.
3. Inhibition of AFAP1L1 expression in OS cells and in animal models of OS will reduce metastatic disease, thus cement AFAP1L1 as an important potential therapeutic target
4. Critical regions of AFAP1L1 can be used as dominant negative moieties to reduce the metastatic potential of OS cells and thus uncover potential avenues to guide the development of targeted therapies for metastatic OS.

Aims

1. To knockout AFAP1L1 gene expression in cell and animal models of OS and ascertain its importance for tumour development and metastasis through controlling cell migration and invasion in vitro and in vivo.
2. To correlate the expression level and activity status of AFAP1L1 (phosphorylation) with OS development and metastasis; providing strong evidence for its potential as a diagnostic and/or predictive marker of disease development.
3. To identify minimal critical regions of AFAP1L1 that regulate OS migration, invasion and metastasis in vitro and in vivo, and can act as dominant negative moieties, potentially identifying targetable motifs for the purpose of therapeutic development.

Contact
Associate Professor Evan Ingley  - Evan.ingley@perkins.uwa.edu.au

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