Poster No. 32 Title: MicroRNA Expression Profiling: Connecting Lung Development and Lung Cancer Authors: Sana Mujahid, MaryAnn Volpe, Heber Nielsen Presented by: Sana Mujahid Departments: Department of Cell, Molecular and Developmental Biology, Tufts University School of Medicine; Department of Pediatrics, Tufts Medical Center Abstract: MicroRNAs are a class of small RNAs that regulate gene expression by imperfectly pairing with the 3’UTR sequence of their target mRNAs, resulting in translational repression. Previous studies report a correlation between those genes up regulated during lung cancer and those involved in controlling normal fetal lung development. Our lab has been studying mechanisms necessary for normal fetal lung development. We recently have begun to study how miRNA mechanisms contribute to the regulated expression of genes involved in lung development. We have begun by using a miRNA qRT-PCR based screen of fetal mouse lungs during the critical period of development from a pseudoglandular to a saccular lung in preparation for survival at birth. One goal of this study is to find specific miRNA species which actively regulate gene expression for normal development and which also become reactivated during the progression of lung cancer. 34