Talc Mediates Angiostasis in Malignant Pleural Effusions Via Endostatin Induction

According to a report released from the University of Florida, using talc for pleurodesis procedures is the most effective agent to harden the tissue. However, it is still unclear how effective talc is in completely resolving pleural malignant mesothelioma.

The study evaluates blood flow in the pleural space in patients with malignant pleural effusions (MPE), which is malignant fluid accumulation in the chest. Researchers collected samples of the pleural fluid before and after the talc was instilled into the chest cavity. Researchers were comparing endostatin levels.

Endostatin is a naturally occurring protein in the body that prevents blood vessels from forming and feeding tumor cells. In the lab, the ability to produce endostatin was compared between pleural mesothelial cells (PMC) and malignant mesothelial cells (MMC).

Results:
Pleural fluids from patients with MPE who received a talc pleurodesis contained significantly higher levels of endostatin as compared to endostatin levels before the talc was instilled. Furthermore, talc activated PMC released significantly greater amounts of endostatin (1052.39+/-38.66 pg.ml(-1); P<0.001) when compared to a MMC line (134.73+/-8.72 pg.ml(-1)).

Conclusions:
The study concludes that talc alters the angiogenic balance in pleural space. Instead of maintaining active blood flow to the tumor cells, talc effectively inhibits blood vessel activity. In other words, functional improvement following talc poudrage in patients with malignant pleural effusions may, in part, reflect these physical alterations in the pleural space.

Dept of Medicine, College of Medicine, University of Florida, P.O. Box 100225, Gainesville, FL 32610-0225.

Authors: Najmunnisa, N.; Mohammed, K.A.; Brown, S.; Su, Y.; Sriram, P.S.; Moudgil, B.; Loddenkemper, R.; Antony, V.B.

National Center for Biotechnology Information. PubMed. http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=17251235&query_hl=1
&itool=pubmed_docsum

Jan. 24, 2007. Feb. 20, 2007.

*** POSTED FEBRUARY 20, 2007 ***