NKX3.1, a protein that suppresses the development of prostate tumors, promotes the growth of a different type of tumor in the blood, according to an article published online on September 20 in the Journal of Experimental Medicine.

Paul-Henri Romeo and colleagues find that TAL1, a abundantly expressed in approximately 40% of patients with T cell acute lymphoblastic leukemia (T-ALL), drives expression of NKX3.1. Eliminating NKX3.1 halted the growth of TAL1-expressing T-ALL cells in culture and after injection into mice.

It's not yet clear how NKX3.1 sustains the growth of T-ALL cells, but these findings show that this protein can either halt or hasten tumor development depending on the tissue environment.

More information: Kusy, S., et al. 2010. J. Exp. Med. doi:10.1084/jem.20100745. www.jem.org/