Principal Investigator David Bartel
Co-investigator Michael Hemann
By disrupting the regulation of particular targets, several groups, including ours, have demonstrated the importance of miRNA-directed regulation during each stage of plant development. Efforts, often in collaboration with Bonnie Bartel's lab, have focused on the repression of the messages of NAC-domain transcription factors, auxin-response transcription factors, HD-Zip transcription factors, and ARGONAUTE1, a protein crucial for plant miRNA function. With regard to miRNA function in mammals, we showed that miR-196 directs the cleavage of HoxB8 mRNA during mouse embryonic development and also appears to repress paralogous Hox genes. More recently, we worked with Michael Hemann to show that disrupting the miRNA regulation of the Hmga2 oncogene enhances oncogenic transformation. Because many human tumors possess defective Hmga2 genes that lack the miRNA complementary sites, our work indicates that losing miRNA regulation of this oncogene contributes to human cancers.