Basic and translational research in redox-related cancer medicine, with current focus on ascorbate (vitamin C, ascorbic acid) as pro-oxidant agent in cancer treatment.
High dose of intravenous ascorbate are widely used to treat cancer and infections by complementary and alternative medical practitioners. The efficacy and underlying scientific basis are poorly understood. On the other hand, little side effects were found in these treatments and in a Phase I clinical trial in cancer patients. Early observational studies and recent case reports show positive effect of ascorbate in cancer treatment. Furthermore, we're still in lack of treatment options for a large number of cancers. Ascorbate as a low toxic and potentially effective agent may have great merits that worth investigation.
Physiologic concentrations of ascorbate are tightly controlled through oral ingestion. Intravenous or intraperitoneal administrations can by-pass the tight control mechanism and achieve pharmacologic concentrations in millimolar range. In contrast to its normal anti-oxidant role, ascorbate in pharmacologic concentrations has pro-oxidant action in extravascular spaces, by generating ascorbate radical and hydrogen peroxide (H2O2) to tissues, with minimal formation of these compounds in blood. The pro-oxidant action of ascorbate induced selective cell death to some cancer cells but not to normal cells. An intraperitoneal ascorbate treatment regimen reduced tumor growth by 40~50% in three kinds of highly aggressive tumors in mouse models.
Qi Chen, PhD
PhD, Department of Biochemistry, Sun Yet-sen University, China 2003
Postdoctoral Fellow, NIDDK / NIH, 2008
Dr. Chen accepted a position as Assistant Professor of Pharmacology at KUMC in November 2008. Before she joined KUMC, Dr. Chen completed the postdoctoral training in Laboratory of Molecular Clinical Nutrition in the National Institutes of Health (NIH). Dr. Chen's lab is conducting researches focusing on the following respects:
Another research interested in Dr. Chen's lab is the candidate tumor suppressor gene PDSS2 (prenyl diphosphate synthase subunit 2). PDSS2 gene encodes an essential enzyme involved in the coenzyme Q10 (CoQ10) biosynthesis. CoQ10 is a vital electron carrier in the mitochondrial respiratory chain, and is one of the most potent lipophilic anitoxidants in all cell membranes. CoQ10 also takes part in pyrimidine nucleoside biosynthesis and may modulate cell apoptosis and the mitochondrial uncoupling protein. Thus PDSS2 may be important to modulate mitochondrial function and cell apoptosis.