A new research study has investigated how cancer cells 'hijack' blood cells known as platelets, enabling cancer to spread around the body and promoting the growth of new tumours, it was reported today at the annual Royal College of Surgeons in Ireland (RCSI) Research Day.
The findings of this significant new study will inform the development of novel anti-cancer drugs.
Platelet blood cells normally have a role in blood clotting. In patients with cancer, cancer cells moving around in their bloodstream act on the platelets causing them to behave abnormally. The cancer cells encourage the platelets to clot around the cancer cell, protecting the cancer cell from the body's immune system and enabling the cancer to spread to other parts of the body.
Furthermore, the cancer cells cause the clusters of platelets to establish new blood vessels. This new blood source promotes the growth of secondary (metastatic) cancer tumours.
Explaining the significance of the study, senior author Professor Niamh Moran, Associate Professor in Molecular and Cellular therapeutics explained 'This is the first time that the exact molecular mechanisms at play between prostate cancer cells and platelets have been understood. It was already known that cancer patients with a higher platelet count had worse outcomes but we now know what causes this negative effect. Our study paves the way for the development of new anti-cancer treatments that may potentially prevent the spread of cancer.'
The first author on the study was PhD student Annachiara Mitrugno who worked in collaboration with Professor Moran and Professor David Williams, Associate Professor in Geriatric and Stroke Medicine, RCSI and Beaumont Hospital, who has a special interest in platelet research.
The research was funded by the Health Research Board (HRB) Scholars programme in Diagnostics and Therapeutics for Human Disease.
RCSI's annual Research Day provides scientists with the opportunity to showcase their most recent research findings. As one of Ireland's premier research institutions, exposure to world-class research begins at undergraduate level for the College's medical, pharmacy and physiotherapy students, right up to the highest-calibre research-active academic staff.
Additional research presented at the RCSI Research Day:
New insights into bone disease caused by multi-resistant bacteria (MRSA)
A growing problem with huge predicted growth in hip and knee replacements
A surface molecule on bacteria that instructs bone cells to stop growing and die could be the target for new treatments for bone disease. Blocking a specific protein expressed on bacteria could be a way of treating painful bone infections that are resistant to antibiotics, such as those caused by Methicillin-resistant Staphylococcus aureus (MRSA).
Bone disease, or osteomyelitis, affects one in 5,000 people around the world. Osteomyelitis can occur at any age and can occur in any bone. It occurs due to an infection following open wound bone fractures, bone surgery or joint replacement. The cost to the Irish Exchequer of bone fractures is an estimated €12.7 million annually. In 1990, Ireland recorded 1509 hip fractures in the over 60s age group, by the year 2000, this had risen to 3821. With an aging population with an increasingly sedentary lifestyle in Ireland, these figures will continue to rise. Globally, by 2030, the demand for hip replacements and knee replacements is projected to rise by 174% and 623% respectively.
Osteomyelitis is usually caused by the bacterium Staphylococcus aureus a bacteria that typically lives in harmony on human skin and in the nose.
RCSI Researchers have discovered that the ability of S. aureus to latch onto bone cells depends on a specific protein on the bacterium's surface called 'Spa'. Once attached to the bone cell via Spa, the bacteria transmit signals prompting the bone to stop growing. The Spa protein is also responsible for causing destructive inflammation in the bone leading to further damage. The gradual loss of bone cells leads to bone destruction and weakening of the skeletal system.
Dr. Steve Kerrigan Principal Investigator on the research explained how the group's findings could lead to new therapies for osteomylelitis. 'Bacteria that do not have the Spa protein on their surface are unable to bind to bone cells, which prevents them from sending suicide messages or triggering prolonged destructive inflammation,' he said. 'Blocking bacterial attachment to cells via Spa could therefore be a way of treating osteomyelitis, or even preventing it in the first place.'
Therapies that could effectively prevent and/or treat osteomyelitis could greatly improve the quality of life of sufferers. 'The disease causes significant amounts of pain as it affects the bone which is not as exposed as muscles or skin that can be easily massaged to ease the pain,' explained Dr. Kerrigan. 'The pain caused by bone infection is permanent and the treatment is prolonged'.
New treatments for the disease that do not rely on existing antibiotics would be advantageous. 'The danger of invasive bacterial disease is compounded by the emergence of multi-drug resistant bacteria worldwide,' explained Dr. Kerrigan. 'The findings of this study will help develop better diagnostic tools and treatments for osteomyelitis that will not over-rely on antibiotics.'
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