Second in a two-part series on mitochondria. See part 1.
Recent advances in single-cell genomics have made it possible to study individual cells and learn how they develop into specialized cells. However, we have only limited information on cells’ origins and how they’re related to the other cells around them.
Meanwhile, efforts to understand more about how cells differentiate and divide have looked at whole cell categories at a time, offering little knowledge of individual cells.
“It’s like looking at the statistics for a college — you can determine what the average student is like, but you have no idea what any one individual student is doing,” says Vijay Sankaran, MD, PhD, a hematologist at Boston Children’s Hospital. “Learning about cellular relationships is critical — it can help us understand how many stem cells give rise to any tissue in our body, what cell types cancers emerge from, or how some cells can be dysfunctional in particular diseases.”
In 1938, Louis K. Diamond, MD, and Kenneth Blackfan, MD, at Boston Children’s Hospital described a severe congenital anemia that they termed “hypoplastic” (literally, “underdeveloped”) because of the bone marrow’s inability to produce mature, functioning red blood cells. Eighty years later, the multiple genetic origins of this highly rare disease, now known as Diamond-Blackfan anemia, or DBA, are finally coming into view.
Now, 2017: Today, Orkin is associate chief of Hematology/Oncology and chairman of Pediatric Oncology at Dana-Farber/Boston Children’s Cancer and Blood Disorders Center (DF/BC). In this photo, he examines a rendering of a gene regulatory molecule’s structure. Orkin’s lab investigates gene regulation of stem cell development, genetic vulnerabilities to cancer and gene and other therapies for treating hemoglobin disorders. …
While researching a rare blood disorder called Diamond-Blackfan anemia, scientists stumbled upon an even rarer anemia caused by a previously-unknown genetic mutation. During their investigation, the team of scientists — from the Dana-Farber/Boston Children’s Cancer and Blood Disorders Center, the Broad Institute of Harvard and MIT and Yale University — had the relatively unusual opportunity to develop an “on-the-fly” therapy.
As they analyzed the genes of one boy who had died from the newly-discovered blood disorder, the team’s findings allowed them to help save the life of his infant sister, who was also born with the same genetic mutation. The results were recently reported in Cell.
“We had a unique opportunity here to do research, and turn it back to a patient right away,” says Vijay Sankaran, MD, PhD, the paper’s co-corresponding author and a principal investigator at the Dana-Farber/Boston Children’s Cancer and Blood Disorders Center. “It’s incredibly rewarding to be able to bring research full circle to impact a patient’s life.” …
Research going back to the 1980s has shown that sickle cell disease is milder in people whose red blood cells carry a fetal form of hemoglobin. The healthy fetal hemoglobin compensates for the mutated “adult” hemoglobin that makes red blood cells stiffen and assume the classic “sickle” shape.
Normally, fetal hemoglobin production tails off after birth, shut down by a gene called BCL11A. In 2008, researchers Stuart Orkin, MD, and Vijay Sankaran, MD, PhD, at the Dana-Farber/Boston Children’s Cancer and Blood Disorders Center showed that suppressing BCL11A could restart fetal hemoglobin production; in 2011, using this approach, they corrected sickle cell disease in mice.
Now, the decades-old discovery is finally nearly ready for human testing — in the form of gene therapy. Today in the Journal of Clinical Investigation, Dana-Farber/Boston Children’s researchers report that a precision-engineered gene therapy vector suppressing BCL11A production overcame a key technical hurdle. …
Genome-wide association studies are huge undertakings that compare the genomes of large populations. They can turn up thousands to tens of thousands of genetic variants associated with disease. But which GWAS variants really matter?
That question becomes exponentially harder when the variants lie in the vast stretches of DNA that don’t encode proteins, but instead have regulatory functions.
Reporting in Cell, Sankaran’s team and two other groups at the Broad Institute describe a new tool that can looks at hundreds of thousands of genetic elements at once to pinpoint variants that truly affect gene expression or function. Called the massively parallel reporter assay (MPRA), it could help reveal subtle genetic influences on diseases and traits.
In Sankaran’s case, the MPRA is helping him understand how common variants contribute to blood disorders in children. “Most of the common variation is just tuning genetic function,” he says. “Just slightly, not turning it on or off, but actually just tuning it like a dimmer switch.”
Before an audience of several hundred luncheon attendees, physician-scientist Vijay G. Sankaran, MD, PhD, received Boston Children’s Hospital’s 2015 Rising Star Award — recognizing the outstanding achievements of an up-and-coming innovator under the age of 45 in pediatric health care.
Part of the problem may be that, until now, the right tools haven’t been available to exploit GWAS data. But a few recent studies—including two out of Dana-Farber/Boston Children’s Cancer and Blood Disorders Center—have used GWAS data to identify therapeutically promising targets, and then manipulated those targets using the growing arsenal of gene editing methods.