Funding Scientific & Medical Research

Improvements in treatment and diagnostic methods have only happened due to vital ongoing research programs.

Read more - about projects we have funded in the past.

PhD Scholarship to study the role of the cell surface protein CDCP1 in cancer

More than 90% of cancer patients die because their tumour has spread to other parts of the body. Our project will investigate how a cell surface protein called CDCP1 helps cancer cells to spread. We will also work out how an antibody against CDCP1 causes cancer cells to die. This information is necessary if CDCP1 is to be used to block cancer..

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While organ confined cancer can be treated effectively by surgical removal of the tumour, the same is not true for cancer that has spread (metastasised). For these patients, prognosis is poorer and drops significantly the later diagnosis occurs. In fact, greater than 90% of cancer deaths result from metastasis. Due to its complex molecular nature, it has been difficult to identify proteins critical in metastasis.

Our group and other laboratories have shown that a cell surface protein known as CUB domain containing protein 1 (CDCP1) can assist cancer cells to spread. We have shown that CDCP1 does this by helping cells to evade cell death (apoptosis) during a key stage of metastasis as the cancer cells escape from blood vessels. Importantly, very recently using two animal models, we have shown that an antibody that specifically recognises CDCP1 can inhibit the spread of cells. Our data indicate that an antibody binding to CDCP1 prevents cells from evading cell death as they exit from blood vessels.

Significance: We propose that CDCP1 may be a suitable target for inhibiting the spread of cancers in which this protein is dysregulated, including bowel cancer. In particular, CDCP1 may be a useful target for inhibiting the spread of cancer cells that are in the blood system after a patient has undergone surgery to remove a primary tumour. Our current work needs to be extended to cells from other cancers and more information is needed on how CDCP1 helps in evasion of apoptosis and how targeting of CDCP1 induces cell death.

We hypothesise that CDCP1 helps cells from a range of cancers to evade apoptosis by relaying pro-survival signals from the outside to the inside of cells. We propose that antibody binding to CDCP1 prevents the relay of pro-survival signals and results in death.

The aims to test these hypotheses are to:

1. Examine the ability of CDCP1 to facilitate evasion of apoptosis in cells from a range of cancers.
2. Characterise the pro-survival signals relayed by CDCP1 and blocked by antibody binding.

Click here to view the Interim Project Report.

EphB2/ephrinB interaction as a growth regulator of colon cancer

One reason why cancers invade the surrounding tissues and spread to distant organs (metastasis) is because they can evade or have lost the ability to respond to normal control mechanisms. EphB2 is a protein which is part of a normal growth control mechanism in the colon and most colon cancers lose the EphB2 protein as they progress to an invasive/metastatic type. Restoring EphB2 expression to colon cancer cell lines retards their ability to grow as tumours. This study investigates the mechanism by which EphB2 inhibits tumour growth by studying the effects restoring EphB2 expression to colon cancer cells in culture and will also determine the cause of EphB2 induced growth retardation in tumours.

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One reason why cancers invade the surrounding tissues and spread to distant organs (metastasis) is because they can evade or have lost the ability to respond to normal control mechanisms. EphB2 is a protein which is part of a normal growth control mechanism in the colon and most colon cancers lose the EphB2 protein as they progress to an invasive/metastatic type. Restoring EphB2 expression to colon cancer cell lines retards their ability to grow as tumours. This study investigates the mechanism by which EphB2 inhibits tumour growth by studying the effects restoring EphB2 expression to colon cancer cells in culture and will also determine the cause of EphB2 induced growth retardation in tumours.

UPDATED REPORT - 1 JULY 2008
EPHB2/EPHRINB INTERACTION AS A GROWTH REGULATOR OF COLON CANCER
Dr P.V.Senior & Prof S. T. F. Chan

LAY TITLE

Investigation of how Eph B2 inhibits the growth of Colon Cancer

INTRODUCTION

Colon cancer arises in the epithelial lining of the colon. Whilst surgical removal can be curative once the tumour has spread (metastasised) to other organs mortality is high.
One factor in the progression of cancer is the loss of response to normal control systems.

EphB2 is a receptor is expressed on dividing normal colonic epithelium but is lost when they stop dividing. Interaction of EphB2 with ephrins expressed on other cells ensure these dividing cells are contained in their correct location. EphB2 expression is turned off in a high proportion of colon cancers and this correlates with poorer prognosis. The loss of EphB2 appears to remove a restraint on growth and is important in the progression of colon cancer.

The aim of this project is to study the mechanism by which EphB2 inhibits cancer growth. To this end we have used an EphB2 negative colon cancer cell line and introduced an inducible EphB2 construct which allows us to regulate the expression of EphB2.

OBJECTIVES AND PROGRESS TO DATE

Objective

Observe the effects of interaction of EphB2 expressing tumour cells with its ligands (Ephrin B1, B2 & B3) on their growth and behaviour in vitro.

Progress

1. We have demonstrated that EphB2 expression has a profound effect on the tumour cells ability to degrade extracellular matrix and also to migrate in response to chemical attractant. Even low amounts of EphB2 expression can reduce migration 5-10 fold.
2. A number of experiments have been completed showing that expression of EphB2 has little direct effect on cell growth rate in culture. Treatment of EphB2 expressing cells with ephrin B1 similarly has no effect on growth rate. This is consistent with most other studies which suggest the Eph/Ephrin system does not directly regulate cell proliferation.
3. We have also shown in preliminary experiments that EphB2 expression with or without ephrin stimulation has no effect on the response to apoptosis inducers such as the drug etoposide.
4. We have created cells with inducible EphB2 expression using another colon cancer cell line (SW480) to repeat the above studies.
5. We have created a cell line which constitutively express ephrinB1 on the cell membrane for use in co-culture experiments to determine the effect of EphB2/ephrin interaction. These cells are also tagged with a LacZ gene which means they can be stained blue to distinguish them from the EphB2 expressing cells.

Objective

Determine the reason for the retarded growth of in vivo tumours derived from EphB2 expressing cells.

Progress

Analysis of experimental tumours with low, moderate and high levels of EphB2 suggest that growth is retarded in high EphB2 expressing tumours due to a reduction in the proportion of dividing cells. Conversely the level of cell loss due to apoptosis is similar in all three groups.
Using immunocytochemistry we have detected the presence of ephrins on stromal cells surrounding areas of tumour suggesting the potential for EphB2/ephrin interaction.

ONGOING AND FUTURE STUDIES

The negative effect of EphB2 expression on invasion and migration is an important finding. We are interested in determining the effect of EphB2 expression on the levels of genes known to be important in migration and invasion.
EphB2 stimulation in vivo occurs when a cell bearing an ephrin (such as ephrinB1) on its surface interacts with a EphB2 receptor expressing cell. Using a soluble form of ephrin is much less effective in activating EphB2. To overcome this we are:

1. Attempting to create a cell line which has inducible expression of a form of EphB2 which has been mutated to be constitutively active (i.e. permanently switched on). Thus we can study the effect of EphB2 activation in the absence of ephrin stimulation.
2. Use cells which express ephrins on their surface in co-culture experiments to study the effect of cell-cell interaction.

In culture EphB2/ephrin interaction does not have an effect on cell growth but in vivo we see reduced growth of EphB2 expressing tumours. This suggests an indirect mechanism is at work. One possibility is reduced vascularisation, this would constrain tumour growth. We will use immunocytochemistry to assess the vascular status of tumours.

Serrated polyps as precursors of colorectal cancer

Cancer & Bowel Research Trust supports projects conducted by the Gastroenterology Research Laboratory at the IMVS which investigates gene expression, molecular changes and clinico-pathological features of serrated colorectal polyps. These polyps have only recently been recognized as precursors of colorectal cancer and still await their detailed characterization and establishing optimal clinical management.

Dissemination & Metastasis of Colonic Cancer Cells

There is a gene called C-Met which is involved in cell migration. This is particularly dangerous in cancer patients as it means that cancer cells can spread more quickly and easily. In colon cancer patients, death occurs after the tumour has spread, causing metastasis. C-Met isn't a gene that is normally active in colon cells, but it can be activated by the cancer. This research program is going to examine how much impact the C-Met gene has on cancer spreading, and therefore how important it is in the control and treatment of cancer.

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There is a gene called C-Met which is involved in cell migration. This is particularly dangerous in cancer patients as it means that cancer cells can spread more quickly and easily. In colon cancer patients, death occurs after the tumour has spread, causing metastasis. C-Met isn't a gene that is normally active in colon cells, but it can be activated by the cancer. This research program is going to examine how much impact the C-Met gene has on cancer spreading, and therefore how important it is in the control and treatment of cancer.

Death from colon cancer is due to spread of tumour to the liver (metastasis). Genetic changes during the development of cancer leads to over- expression of normal genes not usually expressed in colonic cancer cells. One of these, C- Met, is associated with cell migration and may be an important contributor to metastasis. By manipulating the levels of C- Met in colon cancer cells we can access the contribution of this gene to the process of metastasis using the vivo models.

Aims and Objectives

1. Create human and mouse colon cancer cell lines with either over expression of C- Met or under expression of C- Met (by expression of antisense or dominant negative allele).
2. Determine the effects of modulating C- Met levels on the invasive and metastatic potential of colon tumour cells using both in vitro and the following in vivo models:

a) The effect of C- Met on primary tumour growth following subcutaneous inoculation of tumour cells.
b) Effect of C- Met on the establishment and growth of hepatic metastasis following splenic subcapsular inoculation of tumour cells (cells enter the circulation from the spleen and are trapped in the capillary bed of the liver).
c) Effect of C- Met on lung colony formation following IV injection of tumour cells (cells are trapped in the capillary bed of the lung).

Colorectal Carcinoma

Molecular detection of micro-metastic dissemination in colorectal carcinoma using novel tumour specific markers.

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Molecular detection of micro-metastic dissemination in colorectal carcinoma using novel tumour specific markers.

Principal Investigators: Dr Jenny Hardingham

Colorectal cancer (CRC) is a leading cause of morbidity and mortality in developed countries. In Australia, there are about 11,000 new cases diagnosed annually. The development of disseminated (metastatic) disease accounts for the majority of deaths in CRC. Presently, patients with early stage (A or B) disease are considered 'cured' by removal of the primary colon tumour, while patients with stage C (spread to the local lymph nodes) are offered additional chemotherapy, or radiotherapy in the case of rectal cancer. However, up to 30% of patients who have been diagnosed as stage A or B primary tumours, relapse and die within 5 years of surgery as a result of the metastatic spread of cells from the primary tumour to other organs. This suggests that tumour cells with metastatic potential had been shed from the primary tumour prior to surgery. Alternatively, tumour cells had been dispersed during surgery, either into the peritoneal cavity causing local recurrences, or into the blood circulation or lymph nodes causing metastases in distant organs, particularly the liver.

The ability to detect rare disseminated tumour cells may lead to the reclassification of the tumour stage and therefore identify additional patients at risk of developing metastatic disease. These patients would then be offered adjuvant chemotherapy or radiotherapy. A novel method has been established in this laboratory (immunobead RT-PCR) that uses magnetic beads, coated with an epithelial-specific monoclonal antibody to isolate epithelial (colon) cells. The isolated cells are identified as tumour cells using a molecular technique, RT-PCR for specific gene expression markers. A minimum 3-year post surgery follow-up of the clinical outcome for 42 patients (all stages) showed that the patients who were positive for disseminated tumour cells have a significantly shorter disease-free survival. In A and B stage patients, there was a trend for a poorer outcome in patients who were positive compared to patients who were negative, but further patients need to be included in the analysis to obtain statistically significant results. We have shown that the presence of marker-positive cells in blood samples or intra-abdominal wash samples means that these patients are 5 times more likely to suffer disease recurrence than patients who were negative.

Detection of disseminated tumour cells at presentation may have important prognostic implications, altering the staging of the disease and resulting in the early identification of patients at high risk of disease recurrence. It is now recognised that undetected micro-metastatic disease can contribute to the failure of primary treatment. Establishment of a panel of molecular expression markers specific for tumour cells will enable specific and sensitive detection of rare disseminated tumour cells amongst a population of other cells. Long-term follow-up of patients post surgery will determine if detection of positive cells either in the peritoneal cavity, blood samples or lymph nodes is an independent prognostic marker of disease-free and overall survival. If so, then such 'high risk' patients identified at the time of surgery may be offered adjuvant therapy, which at present is only offered to more advanced stage patients.

Liver Dialysis

Evaluation of ex-vivo liver perfusion system as a liver support device in a porcine model of liver regeneration

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Evaluation of ex-vivo liver perfusion system as a liver support device in a porcine model of liver regeneration

Principal Investigators: Prof Guy Maddern & Dr Emma Mullin

Background

The concept of an "artificial liver" has been in development for over 40 years. Such devices aim to temporarily assume metabolic and excretory functions of the liver, with removal of potentially hepatotoxic substances. Patients that may benefit from such devices are those with fulminant hepatic failure, acute-on-chronic liver failure, primary liver allograft non-function and post-hepatectomy liver failure.

The most common reason for hepatic resection in Australia is the excision of colorectal liver metastases. However, one limitation of this type of surgery is the inability to excise all diseased tissue, while at the same time preserving enough hepatic parenchyma to sustain life. Liver support devices may play a future role in extending the current limits on hepatic resection by supporting the remnant through regeneration.

The aim of this project is to monitor the effect of liver support using an ex-vivo liver perfusion system:

1. On biochemical and clinical parameters reflecting liver function.
2. On liver regeneration and factors known to promote this.

Project Progress

To date we have successfully established the techniques of harvesting a porcine liver and establishing perfusion on an extracorporeal circuit. We have achieved success in maintaining adequate oxygenation via use of a hollow fibre oxygenator. Initial work highlighted the need to overcome peripheral blood shunting and ischaemia of the liver periphery most likely secondary to microvascular spasm and microemboli. Following trials using different agents we are now using an infusion of Glyceryl Trinitrate (GTN), which has improved peripheral perfusion and improved the health of the liver. Individual perfusion of the hepatic artery and portal vein has been successful with appropriate perfusion pressures maintained by use of GTN. We have achieved stability of liver function tests and have demonstrated bile production by the perfused liver. Glucose homeostasis is also satisfactory, with infusion of a combination of insulin, glucose and amino acids in order to provide the liver with nutritional and energy substrate.

To date we have achieved success in perfusing a liver for up to 20 hours.

Future Work

Further work still need to be undertaken to perfect the extracorporeal liver perfusion, mainly in reduction of haemolysis and accurate assessment of blood flows. Once we have reproducibly attained viability we will begin the process of applying this technique to pigs that have undergone a 70% hepatectomy to assess the regenerative response both in terms of physical, biochemical and cytokine parameters.

Chemotherapy Following Surgery For Colorectal Cancer

This project aims to determine if certain groups of the population will benefit from chemotherapy after removal of colon cancer with intention to cure.

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This project aims to determine if certain groups of the population will benefit from chemotherapy after removal of colon cancer with intention to cure.

Aim 1

To perform a cohort study to compare the overall survival rates of patients with Dukes' C colorectal cancer who received curative resection surgery treated with or without adjuvant 5-FU-based chemotherapy.

Hypothesis to be tested: Patients with hypermethylated MGMT gene promoter region benefit from adjuvant 5-FU-based chemotherapy and have a lower risk of recurrence of cancer.

Aims 2

To compare the overall survival rates of patients with Dukes' C colorectal cancer treated with curative surgery alone.

Hypothesis to be tested: Is immunohistochemistry (widely available and reliable) an alternative to MSP method of assessing status of MGMT gene in tumour tissue.

Research Plan

The impact of methylation of MGMT gene in survival rate from sporadic CRC will be investigated in a relatively large, population based cohort of patients from the Royal Adelaide Hospital (RAH) who were treated by surgery alone or by surgery and chemotherapy. Minimum data collection for each patient will be sex, age, site of cancer, stage of tumour, microsatellite instability status, methylation of MGMT, immunohistochemistry of MGMT, use of 5-FU-based chemotherapy and overall survival. Molecular analysis for MSI will be carried out using the BAT26 and BAT40 mononucleotide repeat and using PCR-fluorescent technique.

CRC patients will be divided into subgroups according to methylation of MGMT status. Survival rates for 5-FU-treated and non-treated (surgery alone) patients will be compared within each of these groups. Survival analysis will include crude survival, actual survival using the standard Kaplan-Meier procedure and relative survival with the use of computer program.

Potential significance of the overall project

By comparing population-based data on the survival of CRC patients treated with or without standard 5-FU chemotherapy, this project aims to validate results from recent study 1.

Confirmation of these findings would:

1. Question the use of 5-FU chemotheraphy in all Dukes' C stage cancers prompting consideration of giving adjuvant chemotherapy to patients who would benefit from this treatment.
2. Stimulate research into molecular basis of response to 5-FU-based chemotherapy and role of MGMT status on outcome of treatment in colon cancer.