At Drexel, watching stem cells pick their fate — in 3D

On the fifth floor of Drexel University’s Bossone Research Center is a lab about the size of the home movie theaters rich people gloated about on “MTV Cribs.”

On a Friday afternoon in November, Drexel computer and electrical engineering professor Andrew Cohen takes a seat inside. In front of him is a giant projection screen; to its side, an Alienware laptop. He boots up a computer program, uses his mouse cursor to toggle on a few settings, and then hands this reporter a pair of 3D gaming glasses.

Oblong red and green objects jump off the screen.

Cohen, who’s also wearing a pair of gaming glasses, gestures toward the screen and says the software making these lumps of red and green seemingly float in mid-air is helping to answer the “Holy Grail” of questions in microbiology: How a stem cell, the building block of regenerative medicine, determines its own fate just before dividing into smaller, daughter cells.

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In terms of movies of live cells in 3D with multiple channels, there’s virtually nothing out there.

Along with Ph.D. candidate Eric Wait and a team of researchers, Cohen is developing a one-of-a-kind software tool to let biologists look at cell division up close and in three dimensions. It’s called LEVER, shorthand for Lineage Editing and Validation program.

The applications are potentially transformative, as the key to ascertaining the power of regenerative stem cells as well as rapidly proliferating cells that cause cancer lies in the ability of biologists to precisely track how and why cells divide in the way they do. The images of cells Cohen displays on the projection screen on that November afternoon come from the Neural Stem Cell Institute in Rensselaer, New York, which has been using Cohen’s software through the course of its decade-long development.

“There’s no software to look at what biologists capture, let alone measure,” said Cohen, who moved to Philadelphia to take a position within Drexel University’s engineering department three years ago. “In terms of movies of live cells in 3D with multiple channels, there’s virtually nothing out there.”

Biologists track cell division by examining time-lapse images of cells and then plotting, by hand, when cells multiply. It’s a long, oftentimes tedious, but important process: knowing when cells divide over time helps biologists when they study cancer-cell proliferation and the viability of regenerative stem cells.

LEVER instead lets a biologist work with a computer to differentiate and color-code cells — green for stem cells, red for blood vessels — and track the exact moment of their division. Add a pair of 3D gaming glasses, and biologists can view an animated, 3D rendering of the cells they’re studying, almost like they’re watching a film inside an IMAX theater.

“Stem cells in the body live in these micro-environment niches. The environment around them really controls what they do,” said Sally Temple, a cell biologist who has been using LEVER at the Neural Stem Cell Institute. “Studying this very delicate microscopic environment — we have really not had the ability to study that in depth and to quantify it, and LEVER helps us do that.”

LEVER’s marquee feature is the measurement tool, a white, planar grid that inserts itself between blood vessels and stem cells and can be toggled on while in 3D view. If the grid is parallel to the blood vessel, the adjoining stem cell will divide into one daughter cell close by and another farther away. If the grid is perpendicular to the blood vessel, the two daughter cells will be equidistant to the blood vessel. Biologists think that the orientation of blood vessels to stem cells plays a role in the fate of the cells.

Cohen hopes to make the LEVER software open-source so any biologist can use the program.

A stem cell dividing. (Photo by Andrew Zaleski)