Madrid, 2 APR ( EFE).- Researchers at the National Center for Cancer research ( CNIO) have created transgenic mice in which, thanks to a few genes luminescent, it can be seen as progress vessels accompanying tumors, which is essential to observe their growth and how to generate the metastasis lymph.

One of the main roads which used the cancer cells spread by the body and create metastasis is the lymphatic system, but this is still little understood process.

The mice created by researchers at the CNIO, led by Sagrario Ortega, will help to study this process and find out what tumors more use the lymphatic system to expand.

Technique, appearing tomorrow in the journal Proceedings, is so accurate that it even allows to see which lymph nodes are about to be invaded by tumor cells.

Although simple seen mice created by the Ortega group they appear normal, they have several additional luminescent genes that are expressed in the walls of lymphatic vessels.

One of these genes is a protein called luciferasa, responsible for the fireflies emit light.

When a substance which acts on the luciferasa is injected in mice, the lymph vessels of mice emanate a light that is captured in the dark by special cameras.

Another gene, the green fluorescent protein (GFP), allows to visualize the lymphatic vessels to any cellular level.

These mice are very useful to study cancer and metastasis because its lymphatic vessels emit much more light when they are proliferating, something occurring in the presence of tumors.

When a tumour grows into a tissue grows also the lymphatic network surrounding it and the cancer cells rely on these new ways to move and form metastases.

“Today provides several techniques to visualize the blood vessels, but not of lymph proliferation”, explains Sagrario Ortega.

Is the first time “that we see this process in a living animal and with accuracy such that detects the activation of lymph nodes before getting the first tumor cells,” added the researcher.

Therefore, these mice “provide a valuable tool for the study of metastasis and the development and testing of new therapies antimetastásicas”, says Ortega.

The new transgenic mice are already being used by teams of the CNIO to find markers that identify tumors that generate more metastasis by lymphatic route, and also to investigate how to block the process pharmacologically.