The candidate, Anupama Narla, presents a 5-year career development plan that seeks to identify novel therapeutic agents for Diamond Blackfan anemia (DBA) and other disorders of ribosome dysfunction, using three different approaches, while establishing an academic career in translational pediatric hematology.
The specific aims of this proposal are to: (1) determine the mechanism of action of lenalidomide on erythroid differentiation and study its potential role in the treatment of Diamond Blackfan anemia; (2) generate and characterize iPS cells derived from patients with Diamond Blackfan anemia and the 5q- syndrome; and (3) perform an RNAi screen in cells with ribosomal haploinsufficiency in order to identify novel therapeutic agents. Her primary mentor, Dr. Benjamin Ebert, identified RPS14 as the candidate gene for the erythroid phenotype of the 5q- syndrome, and has quickly established himself as a leader in the emerging field of ribosomopathies. Ribosomopathies, which have only very recently been identified in humans, comprise a collection of disorders in which genetic abnormalities cause impaired ribosome biogenesis and function. In addition to DBA and the 5q- syndrome, mutations in other genes required for normal ribosome biogenesis have been implicated in several rare congenital syndromes including Shwachman-Diamond Syndrome, Dyskeratosis Congenita, Cartilage Hair Hypoplasia, and Treacher Collins Syndrome. In a relatively short period of time, the candidate, under the direct supervision of Dr. Ebert, has gained proficiency in all of the technical and methodological skills needed to successfully carry out the objectives of her proposal. She has characterized the effects of dexamethasone and lenalidomide, individually and in combination, on the differentiation of primary human bone marrow progenitor cells in vitro. She found that both agents promote erythropoiesis in normal CD34+ cells and in CD34+ cells with the types of ribosome dysfunction found in DBA and del(5q) myelodysplastic syndrome. She has also identified CBR1 as a target of lenalidomide using stable isotope labeling with amino acids in cell culture (SILAC) in collaboration with the Broad Institute. And she has been instrumental in the generation of an iPS cell line with defective erythropoiesis, derived from a patient with DBA. Her first author paper on the effects of dexamethasone and lenalidomide on erythropoiesis is being re-submitted to Blood in March 2011 after an initial round of positive reviews. She is the first author on three review papers in the field of ribosomopathies which have been or are being published in Blood, International Journal of Hematology, and Seminars in Hematology. She is the second author on a paper that described the erythroid specific effects of p53 activation in ribosomal haploinsufficiency; this paper was featured as a plenary article in the print edition of Blood. In addition, another second author paper which identified the role of a microRNA, miR-145, in the pathophysiology of the 5q- syndrome will be resubmitted to Blood in May 2011. She presented this work as an oral session at the American Society of Hematology in December 2009. Building on her scientific accomplishments in the Ebert lab and her background in pediatric hematology, the candidate has outlined both short and long-term career goals in which she would continue to devote 80% of her effort to research in translational hematology and 20% of her time to clinical practice in bone marrow failure syndromes and education. To accomplish these goals, she has assembled a highly talented team of mentors, advisors, and collaborators. In addition to her primary mentor, Dr. Ebert, the candidate will be co-mentored by Leonard Zon who has an established record of successfully mentoring physician-scientists. Her mentors will meet with the candidate at least monthly to supervise and assist in her transition to independence. David Williams and Nancy Berliner, both division heads and international leaders in hematology, are serving as the candidate's research committee which will meet, at minimum, every six months to ensure a successful scientific research program. The candidate has also recruited George Daley, a leader in the field of iPS technology; Colin Sieff, Director of the Bone Marrow Failure Clinic at Children's Hospital Boston; and Steven Carr, who led the development of SILAC-based target identification which allows for the unbiased identification of proteins that bind to a drug, as collaborators for her project. Finally, the candidate has the benefit of carrying out her proposed research in the Karp Research Building at Children's Hospital Boston which also houses the labs of David Williams, Scott Armstrong, Stuart Orkin, Leonard Zon, Nancy Berliner, and George Daley. This concentration of clinical and scientific expertise on hematopoiesis will be an additional resource to Dr. Narla. Execution of the specific aims and research career development plan outlined in this proposal will allow the candidate to successfully transition to a career as an independent investigator in translational research focused on developing new therapies for disorders of ribosome biogenesis.
The systematic use of three recently developed innovative technologies will be used to identify new and novel therapeutic agents for an emerging category of diseases known as ribosomopathies; which are human disorders of ribosome dysfunction. These technologies include: (1) SILAC-based target identification which will identify small molecule - protein interactions with quantitative proteomics; (2) iPS cell lines derived from diseases of interest which will be used as an in vitro system to test therapeutic agents; and (3) RNA interference screen in iPS cells which will identify genes that when targeted promote erythroid differentiation as well as genes that when inhibited result in cell death only in the presence of ribosomal haploinsufficiency. We anticipate that the use of these three state of the art technologies will allow the identification and testing of new treatments for patients with disorders of ribosome biogenesis.
