The results of the study will help to develop new therapies.
Researchers from the University of Wisconsin in Madison have discovered a protein Munc13-4, which helps cancer cells to distinguish exosomes that stimulate the growth of malignant tumors.
The results of a study published in the journal of Cell Biology, will help to develop new treatments for cancer and to prevent the development of metastasis.
Exosomes represent a microscopic vesicles consisting of lipid membranes and the contained protein molecules and RNA. It is shown that actsoma secreted by cancer cells are substances that stimulate tumor growth. For example, vesicles can transport oncogenes in neighboring cells, enhancing proliferation of the latter, or proteins (e.g., MT1-MMP,) that make the tissue surrounding the tumor vulnerable to the penetration of malignant cells. In addition, actsoma may contain signaling factors that suppress activation of the immune system.
Scientists have found that calcium, which in excess is in aggressive tumors, stimulates the secretion of exosomes from cells of an aggressive form of breast cancer. This is due to the activity of the calcium binding protein called Munc13-4. He and other protein — Rab11 is involved in the formation of multivesicular Taurus, which contain exosomes. The suppression activity of this compound or the replacement of the encoding gene defective copy makes the cell unable to bind calcium. This, as shown by researchers, prevents the secretion of the vesicles, contributing to the formation of metastases in response to calcium.