Guo S, Bai H, Megyola CM, Halene S, Krause DS, Scadden DT, Lu J. 2012. Complex oncogene dependence in microRNA-125a-induced myeloproliferative neoplasms. Proceedings of the National Academy of Sciences of the United States of America. 109(41):16636-41. Pubmed: 23012470 DOI:10.1073/pnas.1213196109


Deregulation of microRNA (miRNA) expression can lead to cancer initiation and progression. However, limited information exists on the function of miRNAs in cancer maintenance. We examined these issues in the case of myeloproliferative diseases and neoplasms (MPN), a collection of hematopoietic neoplasms regarded as preleukemic, thereby representing early neoplastic states. We report here that microRNA-125a (miR-125a)-induced MPN display a complex manner of oncogene dependence. Following a gain-of-function genomics screen, we overexpressed candidate miR-125a in vivo, which led to phenotypes consistent with an atypical MPN characterized by leukocytosis, monocytosis, splenomegaly, and progressive anemia. The diseased MPN state could be recapitulated in a doxycycline-inducible mouse model. Upon doxycycline withdrawal, the primary MPN phenotypes rapidly resolved after the discontinuation of miR-125a overexpression. However, reinduction of miR-125a led to complex phenotypes, with some animals rapidly developing lethal anemia with extensive damages in the spleen. Forced expression of miR-125a resulted in elevated cellular tyrosine phosphorylation and hypersensitivity toward hematopoietic cytokines. Furthermore, we demonstrate that miR-125a targets multiple protein phosphatases. Our data demonstrate that miR-125a-induced MPN is addicted to its sustained overexpression, and highlight the complex nature of oncogenic miRNA dependence in an early neoplastic state.

Related Faculty

Photo of David Scadden

David Scadden’s laboratory is dedicated to discovering the principles governing blood cell production, with the ultimate goal of guiding the development of therapies for blood disorders and cancer.

Search Menu