For the first time, a treatment in mice has shown promise against the final, metastatic stages of terminal cancer. Unusually, the antibody targets healthy tissue, not tumour cells, suggesting normal cells play an unwitting role in terminal cancers.
The mouse treatment uses an antibody that binds exclusively to a receptor found on healthy epithelial cells lining organs and blood vessels, called platelet endothelial cell adhesion molecule 1 (PECAM-1).
鈥淚t is both unexpected and counter-intuitive that a receptor expressed on normal epithelial cells plays a significant role in orchestrating the fatal progression of advanced metastases,鈥� says of the California Pacific Medical Center Research Institute in San Francisco, head of the research team.
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By blocking access to the receptor on healthy cells, the antibody halted further growth of tumour cells in mice; some tumours even got smaller. Experiments are now under way in Debs鈥檚 lab to try to establish how masking the receptor disrupts tumour growth signals.
The antibody also stopped the weight loss, muscle atrophy and fatigue that characterises terminal cancer.
Debs and his colleagues found that the antibody stopped the growth of secondary tumours from breast, lung, colon and melanoma cancers in mice. But the antibody didn鈥檛 work against earlier, less-aggressive stages of cancer, suggesting it disrupts a process common only to the final stages of major cancers.
鈥淕iven its dramatic activity against pre-terminal metastases,鈥� Debs says. 鈥淲e suspect the antibody will be effective in significantly prolonging life.鈥�
This study suggests that we could potentially target and destroy cancer even after it has spread, says Margaret Frame of Cancer Research UK. 鈥淔urther testing and refinement is needed to establish the value of this as a potential treatment, but it is very encouraging.鈥�
Journal reference: , DOI: 10.1073/pnas.1004654107
