A potential new therapeutic target has been identified in two types of aggressive blood cancers.
A team at the Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC) in Spain made the discovery whilst investigating the growth of B cell lymphomas – blood cancers which originate in a specific type of immune cell called a B cell.
The two B cell lymphomas of interest in this study were Burkitt’s lymphoma – a type of lymphoma particularly prevalent in African countries – and diffuse large B cell lymphoma – the most common type of high-grade non-Hodgkin Lymphoma.
Approximately 60% of those diagnosed with these types of lymphoma have an aggressive form of the disease meaning many patients do not respond to chemotherapy or experience disease relapse at some point in their lives.
The target discovered by the CNIC team is called miR-28 which exists as a very short sequence of RNA called microRNA. RNA acts as a messaging molecule from DNA sequences that dictate the function of specific molecules within the cell.
The team found that miR-28 regulates the multiplication of B cells by inhibiting a process called ‘terminal differentiation’. This is a pivotal stage of the cell cycle that dictates whether a B cell will multiply or not.
In lymphomas, researchers realised miR-28 was often lost in lymphomas and re-establishing its expression slowed tumour growth.
“The presence of miR-28 reduces the proliferative capacity and survival of mature B lymphocytes,” said Dr Almudena Ramiro, research coordinator at the CNIC. The team discovered that miR-28 is often lost in lymphomas and that introducing a synthetic copycat molecule of miR-28 into tumours could slow tumour growth.
The findings suggest that a synthetic copy – or ‘analogue’ – of miR-28 could potentially have anti-cancer effects if used therapeutically.
The study authors conclude that by emphasising the need for drugs that can improve the effectiveness and reduce the toxicity of current lymphoma therapies, particularly with respect to the low level of chemotherapy response and high level of relapse seen in both Burkitt’s and diffuse large B cell lymphoma.
“We need to find alternative therapies to replace or complement those that are already available,” said Dr Ramiro.