Lehigh University
Lehigh University


Cassimeris receives prestigious award for research on cell mitosis

“It takes you places you never dreamed when you began.”

Lynne Cassimeris, professor of biological sciences, makes this statement about cell biology - her passion, but a field she has to work hard to sell to students. And her work has not gone unnoticed; she was recently awarded the Keith R. Porter Endowment for Cell Biology, a prestigious award given annually to two researchers.

The foundation funds the winners for three years, helping them put together a conference of their choice and to present a program to smaller colleges and universities about the relevance of cell biology.

Keith Porter, who died in 1997, was one of the first scientists to take a photograph of a cell with an electron microscope, which led to his discovery of an internal cell structure that he called the “endoplasmic reticulum.”

“This is really an honor,” says Cassimeris, who also works with microscopy and directs the Confocal Light Microscopy Facility at Lehigh. The microscope helps focus through thick specimens.

Cassimeris, who does research in mitosis, or cell division, has spoken to biology departments at schools with smaller science programs to encourage students’ interest in cell biology and to share advances in the field.

In her outreach missions, Cassimeris tells students how cell biology and an understanding of mitosis can have vital applications to human health. For instance, many cancer treatments destroy protein formations called microtubules that are involved in the separation of chromosomes during cell division. A better understanding of these proteins could help scientists develop a cancer treatment that does not harm good proteins or good cells, thus reducing serious side effects that some cancer patients now must face.

Cassimeris discussed this example several years ago when she spoke to students at San Juan College in Farmington, New Mexico. San Juan College’s programs are small, Cassimeris says. Although applications of cell biology are broad, many San Juan students are merely asked to memorize the stages of cell division without exposure to how the process really works. Cassimeris showed the students that there is more to cell biology than still diagrams in a book.

“I tried to convey that cells are very dynamic inside, that they’re not static,” Cassimeris says.

Cassimeris started her outreach work in New Mexico after mentoring an assistant professor at New Mexico State University through a program funded by the National Institutes of Health that seeks to improve biomedical research in New Mexico. She hopes to visit several other colleges in the state, including the University of New Mexico at Gallup, which has the largest Native American student population of any public university in the world.

A preference for live cells

Mitosis was not always Cassimeris’s main focus. When she started studying biology, she had an interest in pathology because she loved looking at cells under a microscope. But she realized she would rather study a cell as it divided than to analyze cells that were already dead. “I realized that cells were much more dynamic than what I saw in a textbook … things are constantly moving, changing, interacting,” she says.

Mitosis, the process cells undergo during division, comprises several phases in which chromosomes replicate and divide, eventually forming two new identical cells. Replicated chromosomes are separated by microtubules, which are strands of proteins. The microtubules shoot out toward the chromosomes and must latch on at a specific point, Cassimeris explains. The microtubules themselves are regulated by many other proteins. Cassimeris wants to understand how these proteins work together during the separation of the chromosomes.

Normal cells usually contain two groups of microtubules, one on either side of the cluster of chromosomes. In cancer cells, however, a third group of microtubules sometimes forms. There is debate over whether this is a cause or an effect of the rapid growth and division of cancerous cells, she says. Understanding how these proteins work could have many implications, one being the possible development of a new cancer drug that does not harm regular cell mitosis but only halts mitosis in cancerous cells by blocking the function of microtubules.

Cassimeris has held positions on review panels for the National Institutes of Health, the American Cancer Society, the Department of Defense Breast Cancer Research Program and the National Science Foundation. She has also written chapters of online textbooks.

--Kristen Willard ‘05

Posted on Thursday, June 02, 2005

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