image: Guillermina Lozano, Ph.D., is a professor and chair of the department of genetics. Mien-Chie Hung, Ph.D., is vice president for basic research, professor and chair of MD Anderson's Department of Molecular and Cellular Oncology. view more
Credit: MD Anderson
HOUSTON - Innovative insights into a vital tumor-suppressing mechanism that is often broken in malignant cells and a type of receptor protein that frequently goes haywire to stimulate cancer growth have earned two scientists at The University of Texas MD Anderson Cancer Center membership in a distinguished association of scholars.
Mien-Chie Hung, Ph.D., vice president for basic research, professor and chair of MD Anderson's Department of Molecular and Cellular Oncology, and Guillermina Lozano, Ph.D., professor and chair of the Department of Genetics, have been elected fellows in the American Association for the Advancement of Science.
"Outstanding basic science research provides the foundation for improving cancer treatment and prevention," said Raymond DuBois, M.D., Ph.D., executive vice president and provost at MD Anderson. "Election as AAAS Fellows recognizes Mien-Chie Hung and Guillermina Lozano for their leadership in uncovering the molecular details that reveal how cancer develops, grows and might be eliminated."
Both scientists, DuBois noted, also work closely with clinicians to translate their findings to clinical applications.
New fellows will be inducted in a ceremony on Feb. 19 at the AAAS annual meeting in Washington, D.C. Founded in 1848, the AAAS is the world's largest general scientific society. Nominations are offered by at least three existing fellows in one of the association's 24 sections, or by the section's steering group, or by the AAAS chief executive officer. The steering groups review nominations and send a final list to the AAAS Council for a vote.
After Hung and Lozano are inducted, MD Anderson will have 11 AAAS members on its faculty.
In its announcement, the AAAS cited Hung for "distinguished contributions to novel findings about how receptor tyrosine kinases operate, which have generated a paradigm-shift on receptor biology with important clinical implications."
Lozano is recognized "for distinguished contributions to the field of cancer genetics and molecular biology increasing the understanding of the p53 tumor suppressor pathway and its physiologic significance."
Discovering secrets of receptor tyrosine kinases
Tyrosine kinases are enzymes that regulate many cell functions by attaching phosphate groups to other proteins. They carry signals from growth factors outside of the cell that connect with these receptors on the cell surface. Cancer cells are often overloaded with receptor tyrosine kinases.
Hung was one of a trio of scientists who cloned the functional human epidermal growth factor receptor 2 (HER2/neu) oncogene, which is now known as a marker for poor prognosis for many human cancers and as a successful therapeutic target. The drug Herceptin targets the receptor in HER2-positive breast cancer.
Hung also showed that the receptor tyrosine kinase EGFR also makes its way from the cell surface to inside its nucleus, where it promotes cancer growth in an entirely different way, a discovery that opened a new avenue for receptor biology and cancer drug development. Additionally, Hung and colleagues found that EGFR on the cell surface helps another surface protein channel glucose to cancer cells.
Understanding p53, the protector
The p53 protein is central to regulation of the cell division cycle. It can halt the process, initiate repair of defective DNA and if repair fails, order the cell to kill itself, a process called apoptosis. This frontline defense against cancer is mutated, deleted or otherwise inactivated in more than half of human cancers.
Lozano was first to establish p53 as a transcriptional activator of other genes. Transcription is the first step in a gene's expression of its protein. She also showed that common p53 mutants fail to launch transcription. Lozano also discovered that another protein, Mdm2, plays a critical role in regulating p53 activity.
She also demonstrated that p53's ability to halt the cell cycle and protect chromosomal stability through DNA repair are as important as its ability to initiate apoptosis in preventing tumor development.
Other AAAS fellows at MD Anderson are DuBois, Marvin Meistrich, Ph.D., professor in the Department of Experimental Radiation Oncology, Jack Roth, M.D., professor in the Department of Thoracic and Cardiovascular Surgery; Isaiah J. Fidler, D.V.M., Ph.D., professor in the Department of Cancer Biology; Waun Ki Hong, M.D. professor in the Department of Head and Neck Medical Oncology and head of M. D. Anderson's Division of Cancer Medicine; Margaret Kripke, Ph.D., emeritis professor of immunology; Robert C. Bast Jr., M.D., vice president for translational research; Louise Strong, Ph.D., professor in the Department of Genetics; and Emil J Freireich, M.D.
The American Association for the Advancement of Science (AAAS) is the world's largest general scientific society, and publisher of the journal, Science (www.sciencemag.org) as well as Science Translational Medicine (www.sciencetranslationalmedicine.org) and Science Signaling (www.sciencesignaling.org). AAAS was founded in 1848, and includes some 262 affiliated societies and academies of science, serving 10 million individuals. Science has the largest paid circulation of any peer-reviewed general science journal in the world, with an estimated total readership of 1 million. The non-profit AAAS is open to all and fulfills its mission to "advance science and serve society" through initiatives in science policy; international programs; science education; and more.
About MD Anderson
The University of Texas MD Anderson Cancer Center in Houston ranks as one of the world's most respected centers focused on cancer patient care, research, education and prevention. MD Anderson is one of only 40 comprehensive cancer centers designated by the National Cancer Institute. For seven of the past nine years, including 2010, MD Anderson has ranked No. 1 in cancer care in "America's Best Hospitals," a survey published annually in U.S. News & World Report.