An international team of researchers lead by the University of Granada (UGR) has proven that mesenchymal stem cells (MSC) may be used as enhancer agents of local and systemic effects of radiotherapy, that is to say, those which affect the irradiated tumour and tumour cells located at a certain distance of the irradiated ones.
This breakthrough, published in the renowned Oncotarget scientific magazine, could lead to a more effective use of radiotherapy, and points to a possible use of radiotherapy in treating systemic cancer, apart from being a local and regional treatment.
MSCs are a type of stem cell, present in a wide variety of tissues (bone marrow, blood and tissue from the umbilical cord, skin, adipose tissue, muscle tissue...) and capable of producing various specialized cells present in human body tissues. For example, they can differentiate (become specialized) into cartilage cells (dendrites), bone cells (osteoblasts) and fat cells (adipocytes).
The 'bystander effect'
The researchers, belonging to the Centre of Biomedical Research (UGR), the Institute of Parasitology and Biomedicine (CSIC), the University of Heidelberg (Germany) and the University Hospital San Cecilio (Granada), have studied the cells' sensitivity to the 'bystander effect' (effect observed in cells near the ones directly exposed to radiation). For that purpose, they used a group of lines of tumour cells and mesenchymal stem cells coming from the umbilical cord stroma, and and they activated the MSCs with radiotherapy.
As José Mariano Ruiz de Almodóvar, professor at the Deparment of Radiology and Physic Medicine (UGR) and leading author of this research, explains, "MSCs have a huge potential for the treatment of cancer, given that they are capable of bury themselves in a tumor and, when preactivated or directly activated by in vivo radiation, release cytokines and tumour suppressor proteins which significantly improve the control mechanisms the ionizing radiation exerts on tumours.
The research, lead by the UGR and carried out on tumoral models implemented in mice, has empirically proven that when radiotherapy is combined with a treatment using MSCs, both the irradiated tumour and those at a certain distance of the irradiated one experiment a reduction of the tumoral growth speed and an increase in neoplastic cells death rate.