Karen T. Liby, Ph.D.

Research Associate Professor of Pharmacology and Medicine

Karen Liby joined the Sporn lab in 2003 and in 2012 has been promoted to Research Associate Professor. Her major research interest is to develop and test new drugs for the prevention and treatment of cancer and to elucidate their molecular mechanisms of action. She has found that the synthetic oleanane triterpenoids (developed by Tadashi Honda and Gordon Gribble in the Department of Chemistry at Dartmouth College) and rexinoids (selective ligands for retinoid X receptors), alone and in combination, are effective agents in animal models of estrogen-receptor negative (ER-) breast cancer and lung cancer. She is now extending these studies to pancreatic cancer and studying the mechanisms of action of these multifunctional drugs.

Her publications have reported that:

  1. The anti-inflammatory and the anti-oxidative activities of triterpenoids are directly correlated (in collaboration with Paul Talalay and colleagues at Johns Hopkins)
  2. The synthetic triterpenoids are exceptionally potent inducers of the cytoprotective and anti-inflammatory enzyme, heme oxygenase-1; the regulatory regions in the human heme oxygenase promoter required for activation by the triterpenoids were also identified.
  3. The synthetic triterpenoids suppresses STAT phosphorylation and induce apoptosis in myeloma and lung cancer cells.
  4. The combination of the rexinoid, LG100268, and a selective estrogen receptor modulator (SERM), either arzoxifene or acolbifene, synergizes in the prevention and treatment of mammary tumors in an ER- model of breast cancer.
  5. New synthetic derivatives of the triterpenoid, betulinic acid, have diverse cytoprotective, anti-proliferative, and pro-apoptotic activities.
  6. The synthetic triterpenoids, CDDO-Methyl Ester and CDDO-Ethyl Amide, prevent lung cancer induced by vinyl carbamate in mice.
  7. A new rexinoid, NRX194204, prevents carcinogenesis in both the lung and mammary gland. This study was also the first description of the anti-inflammatory activities of rexinoids.
  8. The rexinoid LG100268 and the synthetic triterpenoid CDDO-methyl amide are more potent than erlotinib for prevention of mouse lung carcinogenesis.
  9. The synthetic triterpenoid CDDO-methyl ester and the rexinoid LG100268 synergize in the prevention and treatment of ER- mammary carcinogenesis by targeting different cell types and signaling pathways.

She has also written the first review on the synthetic triterpenoids for Nature Review Cancer entitled "Triterpenoids and rexinoids as multifunctional agents for prevention and treatment of cancer."

Her work has been recognized by:
M.D. Anderson Cancer Center Wilson S. Stone Memorial Award
Sidney Kimmel Foundation for Cancer Research Scholar Award