A small group of immune-regulating molecules could trigger lymphoma, according to a study published in the The Embo Journal.
Lymphoma is a type of cancer that affects immune system cells called lymphocytes. Like other cancers, lymphoma occurs when lymphocytes are in a state of uncontrolled cell growth and multiplication. The lymphatic system is responsible for fighting infections or anything else that threatens the body.
Researchers from The Scripps Research Institute (TSRI) in California have discovered that six microRNA molecules – short molecules which are found in nearly all animal and plant cells, may trigger lymphoma when overproduced.
According to the researchers, six microRNA work by binding to the genes and prevent them from being changed into proteins.
The six microRNAs, called miR-17~92, are encoded by a single gene on chromosome 13. The researchers say that previous studies show that immune-related and developmental processes are controlled by miR-17~92, dependent upon the type of cell it is expressed in.
Earlier researches have already established that microRNAs can be overproduced in different lymphomas. The recent research shows that overproduced clusters of microRNAs can be a main cause of the cancers.
The researchers analyzed a colony of genetically engineered mice for the study. The mice contained an artificial gene segment that could be activated to overproduce MiR-17~92 in any chosen cell type.
Overproduction occurred in anti-body producing immune cells in the mice, called B cells. These are the cells that Burkitt lymphoma originates from – a fast growing form of non-Hodgkins lymphoma. Results of the study showed that 80% of the mice developed various types of lymphomas within one year of overproduction of miR-17~92. The researchers then looked at how microRNA clusters work in mouse models whose B cells are engineered to over-express a cancer-inducing “oncogene” called myc. This is a gene whose hyperactivity is a characteristic of Burkitt lymphoma cases in humans, and triggers the overproduction of miR-17~92. Results showed that the overproduction of miR-17~92 in the mice appeared to significantly trigger the development of lymphoma.