Give and Take

[Tom]

I thought this was fascinating. Then again, I find almost all medical research fascinating, so you might not be as easily impressed...lol. Now I need to find out what chemotherapy agents are vascular disrupting agents. It also reminds me that there is seldom a free lunch when treating cancers, but sometimes there is a hidden dessert in the bag after all.
Tom


Drug therapy induces recruitment of endothelial progenitor cells to tumors

Reuters Health
Posting Date: September 21, 2006

Last Updated: 2006-09-21 14:00:18 -0400 (Reuters Health)

NEW YORK (Reuters Health) - Treatment of tumors with vascular disrupting agents causes circulating endothelial progenitor cells (CEPs) to home in on and promote the survival of the targeted tumor, findings from an animal study indicate.

The good news is that treatment with antiangiogenic agents can disrupt CEP recruitment, thereby improving the efficacy of the vascular disrupting agent, according to the report in the September 22nd issue of Science.

"These results reinforce our hypothesis that CEPs mobilized from the bone marrow are a major contributor to the growth of the viable tumor rim after treatment with vascular disrupting agents," senior author Dr. Robert S. Kerbel, from Sunnybrook Health Sciences Centre in Toronto, and colleagues note.

Whether bone marrow-derived CEPs play a role in tumor angiogenesis is controversial, the authors note, primarily because so few of these cells are typically present in the blood vessels of untreated tumors. The findings of Dr. Kerbel's group, however, indicate that treatment changes this, as CEPs mobilize and travel to the tumor.

The viable tumor rim and tumor blood flow could be markedly reduced by disrupting the CEP spike through the use of antiangiogenic agents or by genetic manipulation, the report indicates.

The results "provide a mechanistic rationale for the enhanced efficacy of vascular disrupting agents when combined with antiangiogenic drugs," the researchers conclude.

Science 2006;313:1785-1787.