Contributions of the Department of Defense Congressionally Directed Medical Research Programs to Advances in Cancer Therapeutics.

Nearly a billion dollars is spent annually in the Military Health System (MHS) on cancer diagnosis and treatment, with a large portion of that directed toward breast, prostate, and ovarian cancers. Multiple studies have demonstrated the impact of specific cancers on MHS beneficiaries and Veterans, highlighting the fact that active duty and retired military members have a higher incidence than the general public for many chronic diseases and certain forms of cancer. The Congressionally Directed Medical Research Programs have supported research that has contributed to the development, clinical testing, and commercialization of 11 cancer drugs approved by the Food and Drug Administration to treat breast, prostate, or ovarian cancers.

Wapl antagonizes cohesin binding and promotes Polycomb-group silencing in Drosophila.

Wapl protein regulates binding of the cohesin complex to chromosomes during interphase and helps remove cohesin from chromosomes at mitosis. We isolated a dominant mutation in wapl (wapl(AG)) in a screen for mutations that counteract silencing mediated by an engrailed Polycomb-group response element. wapl(AG) hemizygotes die as pharate adults and have an extra sex combs phenotype characteristic of males with mutations in Polycomb-group (PcG) genes.

Chromatin modifiers, cognitive disorders, and imprinted genes.

In this issue of Developmental Cell, Kernohan et al. link the chromatin regulatory proteins ATRX, MeCP2, CTCF, and cohesin with silencing of H19 and other imprinted genes during critical stages of postnatal brain development, perhaps suggesting a common etiology for several human diseases that exhibit defects in brain development and function.

Characterization of the polycomb group response elements of the Drosophila melanogaster invected Locus.

The Polycomb group proteins (PcGs) play a vital role throughout development by maintaining precise gene expression patterns. In Drosophila melanogaster, PcG-mediated gene silencing is achieved through DNA elements called Polycomb response elements (PREs); however, the mechanism for establishing silencing and the requirements and composition of a working PRE are not fully understood. We have used the computer program jPREdictor to uncover PREs located within the invected (inv) locus.