New anti-cancer antibodies
Researchers at the University of North Carolina, working under the guidance of Professor Nancy Klauber-DeMore, demonstrated the ability of monoclonal antibodies to the SFPR2 protein to suppress malignant growth in animal models of triple-negative breast cancer and aggressive vascular tumor angiosarcoma.
The role of the SFPR2 protein in the process of tumor growth was revealed by the authors in the process of searching for an alternative to the drug avastin (bevacizumab) approved by the US Food and Drug Administration, designed to suppress angiogenesis. This drug is directed against vascular endothelial growth factor, which plays an important role in the formation of new vessels. However, despite the impressive results obtained in some cases of using this drug, not all tumors respond to it, and some of the neoplasms that respond to treatment progress over time.
In search of a solution to the problem of treating avastin-resistant tumors, scientists compared gene expression in blood vessel cells of malignant breast tumors and healthy tissues. The result was the discovery of a number of genes, including SFPR2, the overexpression of which is characteristic of tumor blood vessels.
Further study of the issue showed that SFPR2 is expressed by vascular cells of tumors of various localization, including breast, lung, pancreatic, ovarian, colon, kidney, and angiosarcoma cancers. Moreover, experiments have shown that this protein is a powerful stimulator of angiogenesis. This led the authors to the idea that the suppression of SFPR2 activity may have an antitumor effect and prompted the development of monoclonal antibodies to this protein.
Experiments on laboratory models of angiosarcoma and triple-negative breast cancer have demonstrated the ability of the antibodies synthesized by the researchers to block the proliferation and migration of endothelial cells, as well as the formation of new vessels.
Administration of the antibody preparation to SFPR2 to immunodeficient mice with transplanted allogeneic angiosarcomas provided a decrease in tumors by 58%, and immunodeficient mice with transplanted human breast carcinomas – by 52% compared to the control group. At the same time, the use of avastin did not lead to a significant reduction in the size of tumors.
Treatment with monoclonal antibodies to the SFPR2 protein significantly reduces the number of angiosarcoma cells (right)
compared to the untreated control culture (left).
Pharmacokinetic studies have shown that antibodies circulate in the bloodstream for a long time and mainly accumulate in SFPR2-positive tumors.
The authors note that the developed therapeutic approach is still very far from clinical application, but it opens up new prospects in the development of therapies for tumors that do not respond well to existing drugs.
Article by Emily Fontenot et al. A Novel Monoclonal Antibody to Secret Frizzled-Related Protein 2 Inhibits Tumor Growth is published in the journal Molecular Cancer Therapeutics.
Evgeniya Ryabtseva
Portal "Eternal youth" http://vechnayamolodost.ru based on the materials of the University of North Carolina School of Medicine:
Novel Monoclonal Antibody Inhibits Tumor Growth in Breast Cancer and Angiosarcoma.
23.04.2013