Lead authors Poonam R. Molli, Ph.D., ex-postdoctoral fellow, and Da-Qiang Li, M.D., assistant research professor, from GW's Department of Biochemistry and Molecular Biology, have identified a protein, Arpc 1b, that serves as both an activator as well as a substrate for Aurora A, an enzyme which plays a central role in cellular reproduction in normal cells but is overexpressed in several cancers. This represents perhaps the earliest step in mitosis and serves as the missing link regarding the role this protein plays in starting the cell cycle and what keeps the process in balance. The authors discovered that Arpc1b also exists as a stand alone protein and believe that it might also play an independent role outside its established contribution to actin machinery.

More than just an observation of how cells divide, this discovery also offers a potential target for pharmaceutical therapy. Both Aurora A and Arpc1b are over-expressed in breast cancers. Pharmaceutical inhibitors targeting Aurora A are currently available and thus, could be combined with other future targeting strategies. The researchers discovered that an over-expression of Arpc1b promotes tumorigenic properties of breast cancer cells. Scientists believe that if they can someday find a means of suppressing the activity of Arpc 1b in cancer cell, the balance could be restored to this dynamic yet tightly regulated biological event.

SOURCE George Washington University Medical Center