The National Institutes of Health Lasker Clinical Research Scholars Program: A Decade of Launching Clinician-Scientist Careers.

PURPOSE: In response to the decades-long decrease in U.S. clinician-scientists, the National Institutes of Health (NIH) and the Albert and Mary Lasker Foundation launched the Lasker Clinical Research Scholars Program in academic year 2011 to 2012. The investigators examined the early outcomes of this program. METHOD: Thirty-nine scholars have matriculated into the program as of May 2023. Productivity was assessed for all scholars who joined the program before October 2020 (n = 31). Extramural early-stage investigators (ESIs) were used as a control group, and coarsened exact matching was used to compare the groups. The scholars were compared with the matched ESIs on 4 productivity metrics: publication count, weighted relative citation ratio, clinical impact, and approximate potential to translate. Publication records for both groups were compiled using the NIH Office of Portfolio Analysis' name disambiguation method and manually curated to ensure integrity of the data set. RESULTS: Of the 39 scholars, 29 were compared with 121 matched extramural ESIs. Five years before matriculation, the 2 groups had comparable numbers of publications, but scholars had a higher median weighted relative citation ratio, clinical impact, and approximate potential to translate score. Five years after matriculation, the scholars had a higher median number of publications than the ESIs, and the gap between scholars and ESIs, with scholars having higher scores, had widened for all metrics except approximate potential to translate scores. Of 10 of the 39 scholars at or approaching tenure eligibility, 6 have attained tenure (3 at NIH and 3 in academic institutions), and 4 are on track to attain tenure at NIH. CONCLUSIONS: All the Lasker clinical research scholars are substantially involved in clinical and translational research. Their productivity matches or exceeds that of a matched cohort of ESIs at U.S. academic institutions.

Prognostic, therapeutic, and mechanistic implications of a mouse model of leukemia evoked by Shp2 (PTPN11) mutations.

The SH2-containing tyrosine phosphatase Shp2 (PTPN11) is required for growth factor and cytokine signaling. Germline Shp2 mutations cause Noonan Syndrome (NS), which is associated with increased risk of juvenile myelomonocytic leukemia (JMML). Somatic Shp2 mutations occur in sporadic JMML and other leukemias. We found that Shp2 mutants associated with sporadic leukemias transform murine bone marrow cells, whereas NS mutants are less potent in this assay. Transformation requires multiple domains within Shp2 and the Shp2 binding protein Gab2, and is associated with hyperactivation of the Erk, Akt, and Stat5 pathways. Mutant Shp2-transduced BM causes a fatal JMML-like disorder or, less commonly, lymphoproliferation. Shp2 mutants also cause myeloproliferation in Drosophila. Mek or Tor inhibitors potently inhibit transformation, suggesting new approaches to JMML therapy.

Analysis of Ras-induced overproliferation in Drosophila hemocytes.

We use the Drosophila melanogaster larval hematopoietic system as an in vivo model for the genetic and functional genomic analysis of oncogenic cell overproliferation. Ras regulates cell proliferation and differentiation in multicellular eukaryotes. To further elucidate the role of activated Ras in cell overproliferation, we generated a collagen promoter-Gal4 strain to overexpress Ras(V12) in Drosophila hemocytes. Activated Ras causes a dramatic increase in the number of circulating larval hemocytes (blood cells), which is caused by cellular overproliferation. This phenotype is mediated by the Raf/MAPK pathway. The mutant hemocytes retain the ability to phagocytose bacteria as well as to differentiate into lamellocytes. Microarray analysis of hemocytes overexpressing Ras(V12) vs. Ras(+) identified 279 transcripts that are differentially expressed threefold or more in hemocytes expressing activated Ras. This work demonstrates that it will be feasible to combine genetic and functional genomic approaches in the Drosophila hematopoietic system to systematically identify oncogene-specific downstream targets.

The Drosophila STAT protein, stat92E, regulates follicle cell differentiation during oogenesis.

Signal transducer and activator of transcription (STAT) proteins are transcription factors that play a critical role in the response of a variety of eukaryotic cells to cytokine and growth factor signaling. In Drosophila, the STAT homolog encoded by the stat92E gene is required for the normal development of multiple tissues, including embryonic segmentation, imaginal discs, blood cells, male germ cells, and sex determination. We used multiple approaches to study the role of stat92E in oogenesis. Stat92E RNA expression is strongest in the differentiating follicle cells in the germarium, as determined by in situ hybridization. We generated an ethylmethane sulfonate-induced, temperature-sensitive allele, stat92E(F), in which the mutant protein contains a P506S substitution, located in the DNA binding domain. At the restrictive temperature, mutant females are sterile. Mutant ovaries have multiple defects, including fused egg chambers and an absence of interfollicular stalks cells and functional polar follicle cells. An analysis of mosaic clones, using an apparent null stat92E allele, indicates that Stat92E is required in the polar/stalk follicle cell lineage. We conclude that stat92E is necessary for the early differentiation of follicle cells and for proper germ line cell encapsulation during Drosophila oogenesis.