A National Cancer Institute-designated Comprehensive Cancer Center

Make an appointment: 800-826-HOPE

Kong, Mei, Ph.D.

Laboratory of Mei Kong, Ph.D.
Signal transduction and Cancer Metabolism
Tumor cells often display fundamental changes in metabolism and increase their uptake of nutrients to meet the increased bioenergetic demands of proliferation.  Glucose and glutamine are two main nutrients whose uptake is directly controlled by signal transduction and are essential for tumor cell survival and proliferation.  Altered glucose metabolism in cancer cells is termed the Warburg effect, which describes the propensity of most cancer cells to take up glucose avidly and convert it primarily to lactate, despite available oxygen.   In addition to glucose, glutamine is another essential nutrient whose uptake is directly controlled by oncogenes, and it is critical for cancer cell survival and proliferation.  During tumor growth, increased uptake of nutrients and rapid accumulation of cells can outstrip the supply of essential nutrients, including glucose and glutamine.  How tumor cells survive these temporary periods of nutrient deprivation is unclear, but is necessary for tumorigenesis to persist.  The major goal of our laboratory is to delineate the strategies used by tumor cells to survive periods of nutrient deprivation and then to develop novel therapies targeting nutrient-sensing pathways of neoplastic cells.  Exciting progress has been made over the past 20 years in elucidating how cancer cells survive glucose deprivation via mTOR, AMPK and p53 pathway.  In contrast, less is known about the signal transduction pathways that regulate tumor cells’ survival during glutamine deprivation, in spite of the evidence that has been noticed for many years, that glutamine fell from a high level in normal tissue to a level not detectable in different solid tumors.  Thus, identifying the critical regulators that control tumor cell survival during glutamine deprivation may lead to the development of novel and safer cancer therapies.  We recently discovered that protein phosphatase 2A (PP2A)-associated protein, α4, plays a conserved role in glutamine sensing. α4 promotes assembly of an adaptive PP2A complex containing the B55α regulatory subunit via providing the catalytic subunit upon glutamine deprivation. Moreover, B55α is specifically induced upon glutamine deprivation in a ROS-dependent manner to activate p53 and promote cell survival. B55α activates p53 through direct interaction and dephosphorylation of EDD, a negative regulator of p53. Importantly, the B55α-EDD-p53 pathway is essential for cancer cell survival and tumor growth under low glutamine conditions in vitro and in vivo. In future work, we will focus on understanding how p53 activation regulates tumor cell survival under glutamine deprivation, and identify critical p53 targets that contribute to cancer cell survival under glutamine limitation.  Our long-term goal is to identify the signals that allow communication between oncogenic pathways and tumor cell metabolism and develop novel therapeutics targeting metabolic differences between rapidly-proliferating cancer cells and normal cells.
Regulation of Protein Phosphatase 2A Complexes
Reversible protein phosphorylation is the major regulatory mechanism used by cells to respond to environmental and nutritional stresses.  Aberrant regulation of this activity leads to dysregulated cellular behavior and disease phenotypes, including many forms of cancer. Although we know much about how protein kinases function in specific signaling governed by phosphorylation, whether protein phosphatases are also regulated and actively function in the process to counteract kinase function has not been established. Protein phosphatase 2A (PP2A) is a major serine/threonine phosphatase that regulates many signaling pathways. Unlike kinases, serine/threonine phosphatases are promiscuously active and their specificity is governed largely by associated proteins. Thus, the specificity of PP2A is conferred by assembly of a trimeric complex including a catalytic C subunit, a scaffolding A subunit, and one of the sixteen regulatory B subunits. In addition to interacting with conventional A and B subunits, the C subunit reportedly forms two other distinct complexes with proteins designated α4 (Tap42 in yeast) and Tiprl (Tip41 in yeast).  Our laboratory also interested in characterizing molecular mechanisms underlying the response of PP2A complexes to stress signals.
For more information on Dr. Kong, please click here.

Laboratory Members

Lab Members
Jenny Davies, Ph.D
Postdoctoral Fellow
626-256-4673, ext.30158
Min Pan, Ph.D.
Postdoctoral Fellow
626-256-4673 ext.  30158

Michael Reid, B.S.
Graduate Student
626-256-4673, ext. 30158
Kimberly Rosales, Ph.D.
Postdoctoral Fellow
626-256-4673, ext. 30158
Xazmin Lowman, Ph.D
Postdoctoral Fellow
626-256-4673, ext. 64450
Our Scientists

Our research laboratories are led by the best and brightest minds in scientific research.

Beckman Research Institute of City of Hope is internationally  recognized for its innovative biomedical research.
City of Hope is one of only 41 Comprehensive Cancer Centers in the country, the highest designation awarded by the National Cancer Institute to institutions that lead the way in cancer research, treatment, prevention and professional education.
Learn more about City of Hope's institutional distinctions, breakthrough innovations and collaborations.
Develop new therapies, diagnostics and preventions in the fight against cancer and other life-threatening diseases.
Support Our Research
By giving to City of Hope, you support breakthrough discoveries in laboratory research that translate into lifesaving treatments for patients with cancer and other serious diseases.
  • Radiology is one of the cornerstones of any hospital. It is a key diagnostic branch of medicine essential for the initial diagnosis of many diseases and has an important role in monitoring a patient’s treatment and predicting outcome. Radiology is the specialty considered to be both the “eyes” and “ears” of med...
  • Donating blood and platelets saves lives. We all know this. Yet every summer, potential blood donors become distracted by vacations and schedule changes. As a result, blood donations fall dramatically across the nation, leaving hospitals frantically trying to bring in much-needed blood for their patients. Earli...
  • To be a great cancer hospital, you need a great oncology program. Just ask City of Hope – and Becker’s Hospital Review. The health care publishing industry stalwart, described as the “leading hospital magazine for hospital business news and analysis for hospital and health system executives,” recently selected ...
  • Diagnostic errors are far from uncommon. In fact, a recent study found that they affect about 12 million people, or 1 in 20 patients,  in the U.S. each year. With cancer, those errors in diagnosis can have a profound impact. A missed or delayed diagnosis can make the disease that much harder to treat, as the Ag...
  • Eleven years ago, lymphoma patient Christine Pechera began the long road toward a cancer-free life. She had been diagnosed with non-Hodgkin lymphoma and told by doctors elsewhere that her lifespan likely would be measured in months, not years. Refusing to give up, she came to City of Hope for a second opinion. ...
  • Brain surgery is not for the faint of heart. It takes courage, as well as curiosity and compassion. The truly great surgeons also have a desire to find new, and better ways, of healing the brain. Enter Behnam Badie, M.D., chief of neurosurgery at City of Hope. Now a pioneer in brain tumor treatment, Badie enter...
  • Elizabeth Budde, M.D., Ph.D., wants to encourage infighting. She aims to turn the immune system on itself — to the benefit of patients with acute myeloid leukemia, or AML. AML arises when abnormal white blood cells grow out of control, amassing in the bone marrow and interfering with normal blood cell developme...
  • Six, to date; more soon. Outpatient bone marrow transplants, that is. Finding new ways to deliver quality care with the greatest benefit is a priority for a patient-centered institution like City of Hope. For example, not every bone marrow transplant patient needs to check into the hospital for treatment. In fa...
  • The best measure of success in the fight against cancer is in lives saved and families intact, in extra days made special simply because they exist. Yuman Fong, M.D., chair of the Department of Surgery at City of Hope, understands what precedes that special awareness. When cancer strikes, one minute a person ma...
  • In cancer, expertise matters. So do survival rates, patient safety, patient services and many other factors. City of Hope understands this, as does U.S.News & World Report. The magazine’s 2014-2015 list of best hospitals for cancer once again includes City of Hope, ranking the institution 12 out of 900 elig...
  • At 29, Kommah McDowell was a successful young professional engaged to be married to her best friend. She worked in the financial services sector and kick-boxed to keep in shape and to relax. Then came the diagnosis of triple-negative inflammatory breast cancer, a rare and very aggressive form of breast cancer. ...
  • The well-known drug tamoxifen might not always be the best choice for premenopausal women who have undergone treatment for breast cancer and face a heightened risk of recurrence. A new study suggests that the aromatase inhibitor exemestane, or Aromasin, works slightly better than tamoxifen in preventing cancer ...
  • At age 44, Bridget Hanchette, a mother of three from La Crosse, Wisconsin, was diagnosed with grade IV glioblastoma, the most aggressive type of malignant brain tumor. The cancer grows and spreads quickly, making it difficult to treat. Most patients with this diagnosis are not given much hope, but Hanchette’s i...
  • Survival rates for childhood cancer have improved tremendously over the past few decades, but postcancer care hasn’t always kept up. More children than ever are now coping with long-term complications and side effects caused by their disease and treatment — one of those being learning difficulties. A new ...
  • When Sheldon Querido, a retired manufacturer’s representative, was diagnosed with bladder cancer, his doctor told him that he’d need to have his bladder removed – and that he’d have to wear an external urine-collection bag for the rest of his life. “My first response was ‘I donR...