Researchers at Trinity College Dublin have identified, for the first time in oesophageal cancer, the cancer killing capability of a lesser-known type of immune cell, presenting a new potential therapeutic target.
This study has been published in the journal Frontiers in Immunology.
Oesophageal cancer is a very aggressive type of cancer with poor prognosis, and the 5-year survival rate is typically less than 15 percent.
Linked with obesity, oesophageal cancer is one of the fastest growing cancers in the Western world and incidence is due to double in Ireland within the next few decades.
Current treatment strategies work well but only for a minority (approx. 25 percent) of patients so new treatment options are urgently needed.
New treatment strategies targeting the immune system have had revolutionary effects in other cancer types, but the latest clinical trials show that, disappointingly, immunotherapy offers no real benefit for the majority of patients with oesophageal cancer.
The Cancer Immunopathology research team from the Trinity Translational Medicine Institute (TTMI) based in St James's Hospital, are studying unconventional types of immune cells with lesser known functions.
T cells (a type of white blood cell) are very important in fighting cancer; preventing tumours arising and killing off established tumours if activated in the correct way.
Up until now, the majority of immune-based studies have largely focused on conventional CD8 (cytotoxic) T cells, but unconventional T cells, although less abundant, can also have potent cancer killing ability.
The team investigated a particular type of T cell, known as a MAIT cell (mucosal-associated invariant cell) in oesophageal cancer.
MAIT cells are known to protect against bacterial infections but little is known about what they do in cancer.
The team at Trinity are the first to report the characterisation of MAIT cells in the oesophageal cancer setting.
They looked at MAIT cells blood and tumours from patients with oesophageal cancer or a pre-cancerous disorder called Barrett's Oesophagus, and found that:
Overall, these results reveal an anti-tumour function for a new potential therapeutic target cell in this aggressive cancer type, which is being inhibited by the tumour itself.
Finding new ways to reverse the inhibition of MAIT cell tumour-killing ability may offer a new therapeutic strategy in the fight against cancer.
Research Assistant Professor at TTMI and Principal Investigator, Dr Margaret Dunne said: "Oesophageal cancer rates are rising in Ireland, and improved treatment strategies are urgently needed. By revealing how lesser studied immune cells work in cancer, we can better understand the shortcomings of current immunotherapies and investigate new ways to boost the anti-cancer immune response."
"Immunotherapies have revolutionised cancer treatment but still only work for a minority of people. A more in-depth understanding of underlying biology will be critical to unravel why this is - and to allow more patients to benefit" she added.
Source: Trinity College Dublin