Many of the gene mutations associated with hematologic malignancies (cancers that affect the blood and lymph system) are known to scientists. Frequently, the normal version of these genes are essential for making blood cells grow and mature, but researchers still lack a complete picture of disease-causing mutations. The study team used a genetic approach to investigate the earliest possible steps that occur in blood cells as they first bud from specific sites in the embryo called hemogenic endothelium. The scientists sought to identify key regulatory genes in blood development that if mutated could result in hematologic anomalies.

Using a genetic approach, the investigators traced back the mutations and found them in many of the previously known disease-causing genes, and also identified novel ones, like Pi4Ka, that resulted in disease. Working with several animal models and cell cultures, they learned that Pi4ka was associated with correct hematopoietic development. The gene was important for the maturation of certain blood cell types and when mutated, cells stopped maturing and further expanded leading to anemia and other blood anomalies.

The research demonstrated the contribution of Pi4Ka in normal hematopoiesis, particularly during the differentiation of red blood cells. It also showed that mutations in this gene at a hemogenic stage could result in erythroid and/or myeloid malignancies. The scientists further linked specific mutations of the Pi4ka gene in the emergence of cancer. The study identifies a new potential target for cancer and anemia therapies.

The lead author is Luisa Iruela-Arispe, a member of the UCLA Jonsson Comprehensive Cancer Center, the UCLA Molecular Biology Institute and Eli & Edythe Broad Center of Regenerative Medicine & Stem Cell Research. The first author is Dr. Safiyyah Ziyad at the David Geffen School of Medicine. Other authors are Dr. Jesse Riordan at the University of Iowa, and Drs. Ann Cavanaugh, Trent Su, Gloria Hernandez, Georg Hilfenhaus, Marco Morselli, Kristine Huynh, Kevin Wang, Jau-Nian Chen and Adam Dupuy at UCLA.

The research was supported by the National Institutes of Health and the UNCF/Merck Graduate Science Research Dissertation Fellowship.

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Journal Reference:

1. Safiyyah Ziyad, Jesse D. Riordan, Ann M. Cavanaugh, Trent Su, Gloria E. Hernandez, Georg Hilfenhaus, Marco Morselli, Kristine Huynh, Kevin Wang, Jau-Nian Chen, Adam J. Dupuy, M. Luisa Iruela-Arispe. A Forward Genetic Screen Targeting the Endothelium Reveals a Regulatory Role for the Lipid Kinase Pi4ka in Myelo- and Erythropoiesis. Cell Reports, 2018; 22 (5): 1211 DOI: 10.1016/j.celrep.2018.01.017