Osteosarcoma is the most common form of primary bone cancer affecting teenagers and young adults; as well as the second most common form affecting older adults. This form of cancer often does not respond well to current treatment options and the survival rates for patients have not improved for three decades. Hence, there is great requirement for the development of new therapies.
Although there are now many new potential therapies in development for osteosarcoma, one important limitation has been adequate delivery of the therapeutic drug into the tumour itself. Many drugs are administered by injection and so rely on the blood supply to get to their target. However, tumours are known to have a poor blood supply and so the effectiveness of such treatment is reduced.
What is this research project investigating?
Dr Teresa Coughlan and her research team received funding from the Bone Cancer Research Trust in order to produce a direct way of targeting tumours. They have been working with a ‘friendly’ form of bacteria called Salmonella typhimurium, which prefers to live inside tumours than outside them in normal tissue. This poses an advantage and possible use for this bacteria strain in delivering therapies that kill or alter tumour cells directly while avoiding normal, healthy, tissues; thus reducing side-effects of treatment. Similar techniques using friendly bacteria are considered safe and have already been used in patient clinical trials for other diseases.
How will this project take place?
The team will modify the Salmonella typhimurium bacteria strain to produce ‘RNA interference’ molecules which prevent the production of IGF1R; a protein receptor that is well known in the progression of osteosarcoma. The friendly bacteria will act as a vehicle for transporting these RNA interference agents which reduce the levels of IGFR1 in the tumour and thus destroy cancer-causing molecules in osteosarcoma.
It is hoped that this research will eventually lead to a treatment for bone cancer that is better targeted at tumours and doesn’t affect normal, healthy, tissue. This study showed that further investigation into the modification of this strain of bacteria to ensure direct entry into the tumour cells was required to confirm the technique and its optimum use.