With over 1,000 scientists at Harvard and its eight affiliated hospitals, research at the Harvard Stem Cell Institute (HSCI) spans diseases and disciplines to bring treatments to patients. Our scientists innovate along all stages of discovery: investigating the biological mechanisms that drive disease, building disease models that improve the quality and speed of drug discovery, and engineering new therapies. HSCI researchers published over 250 studies in 2018. Here, we highlight just a few examples.
Exercise may help make the heart younger
Exercise is good for the heart, but scientists still do not completely understand why. Research led by Richard Lee, M.D. and Anthony Rosenzweig, M.D. uncovered one potential reason: exercise stimulates heart regeneration.
The researchers gave mice voluntary access to a running wheel, and administered a labeled chemical to measure the production of new heart muscle cells. They found that healthy mice that exercised made over four times as many new heart muscle cells as their sedentary counterparts. After experiencing a heart attack, mice that exercised showed a larger area of heart tissue where new muscle cells were made.
Because heart attacks and aging lead to a loss of heart muscle cells, figuring out how to promote heart regeneration is key to maintaining a healthy heart.
How to build a whole organism from a single cell
One of the leading scientific journals, Science, named research by HSCI scientists as the 2018 Breakthrough of the Year.
Alexander Schier, Ph.D. and Allon Klein, Ph.D. analyzed the genetics of individual cells in zebrafish and frog embryos during the earliest stages of development. As part of the studies, they created a genetic roadmap for building an entire organism from a single cell.
This technology for tracking cells in fine detail is an invaluable tool for studying what goes wrong in human cells during the progression to cancer, diabetes, and other diseases.
Turning cancer against itself
Cancer cells have a self-homing ability, moving around the body to locate tumors. Khalid Shah, M.S., Ph.D. exploited this ability, engineering self-targeting cells that deliver therapeutic molecules to tumors.
Using CRISPR gene editing, the researchers equipped cancer cells with a therapeutic protein. They also engineered the cells to have a self-destruct mechanism. The engineered cells targeted and eliminated primary and metastatic tumors in mice, and were successfully removed after doing the job.
The study demonstrates that engineered cancer cells are a potential therapeutic strategy for different types of tumors.
Heart research gets a better 3D model
Heart models used in stem cell research are typically made up of flat layers of cells in a dish. One of their major shortcomings is that they do not capture the 3D nature of the heart. An HSCI collaboration between bioengineer Kevin Kit Parker, Ph.D. and cardiovascular researcher William Pu, M.D. set out to solve the problem.
First, the researchers built a scaffold by spinning nanofibers into the shape of a heart chamber. Then, they added heart muscle cells that were either from rats or derived from human stem cells. Their new 3D heart model contracted spontaneously, pumping fluid in and out of the chamber.
By combining bioengineering with stem cell technology, this 3D model can be used to study heart disease and test potential new therapies.
A deeper understanding of cystic fibrosis
Scientists have known for decades that cystic fibrosis is caused by a defective CFTR gene. But until a new study led by Jayaraj Rajagopal, M.D., published in 2018, the specific cells responsible for making CFTR were unknown.
The researchers used single-cell sequencing technology to measure gene expression in the mouse airway. With this data, they built a detailed catalog of many different cell types. This allowed them to identify a rare new cell type, called an ‘ionocyte,’ in which CFTR gene expression was concentrated.
Armed with this new understanding of normal lung biology and lung diseases, researchers can focus their efforts and accelerate progress in fighting cystic fibrosis.
High-fat diet could drive aggressive prostate cancer
Many men who are affected by prostate cancer do not die of it: the tumors are typically slow-growing and self-contained. But when prostate tumors metastasize, or spread beyond the prostate, the disease is invariably fatal.
A study by Pier Paolo Pandolfi, M.D. linked dietary fat, an environmental factor, with aggressive prostate cancer. In mice with a genetic background that predisposed them to prostate cancer, tumors metastasized only when the animals were fed a high-fat diet.
Motivated by these results, Pandolfi is planning a clinical trial to test whether an obesity drug that blocks fat production can be used treat prostate cancer.