Ranhui Duan

Biography

Dr.Duan is interested in determining of molecular and cellular basis of Fragile X, Fragile X-associated tremor/ataxia (FXTAS) and Fragile X-associated premature ovarian insufficiency (POI) all caused by a CGG expansion in the disease gene-- FMR1. Fragile X syndrome is the most common causes of inherited mental retardation. Premuation carriers, especially male can present with a late-onset neurodegenerative disorder---FXTAS. The clinical features and molecular pathogenesis of FXS and FXTAS are completely distinct, moreover the unstable CGG repeats always expand upon maternal transmission. We are trying to understand why FXTAS and FXPOI are selectively affected among permutation carriers and how unstable CGG repeats via replication or other cellular process expand to the full mutation, causing mental retardation. Another research focus in her lab is miRNA and cancer. miRNAs, an average of 22 nucleotides, are post-transcriptional regulators that bind to complementary sequences on target mRNAs resulting in translational repression. Studies have focused on breast cancer and brain tumors. Our hypothesis is that aberrant expressed miRNAs with their gene targets which are tumor suppressor genes or oncogenes integrate into a network initiating the cancer process. We collaborate with numerous clinicians to perform these experiments. Tumor and adjacent tissues are being used to determine which miRNAs and target genes are misregulated. Further functional analysis studies of these genes may provide valuable information on the etiology of the diseases. Trainees in Dr. Duan’s laboratory have the opportunity to investigate the mechanisms of fragile-X associated disorders and to identify specific miRNAs and their targets involved in the cancer. To address these issues, we will use a variety of approaches, including molecular and cell biological analysis, genetic manipulation of mouse and drosophila models to identify key targets involved in the significant complex phenotype consequences, to develop new diagnostic and therapeutic approaches, to provide educational support for affected individuals and their families.

Research Interest

molecular ,neurodegenerative disorder