Massachusetts Institute of Technology
Sign in | Create Account

DNA Mutation, Repair and the Environment

06/07/2006 10:00 AM 46-3002
Leona Samson, Director, Center for Environmental Health Sciences and Professor of Toxicology, and; Biological Engineering;; Ellison American Cancer Society Professor;

Description: Forget cigarette smoking (well, not completely). The really bad news, says Leona Samson, is that by virtue of the act of living, a human body will be exposed to destructive threats from the environment, and from within itself. Charbroiled burgers, sunlight, pollution, and even how our bodies use oxygen all pose what Samson calls -insults” to the DNA of our cells. Our success in fending off these inevitable DNA-damaging agents in the environment depends a lot on inheritance, Samson tells us. For instance, victims of the rare disease Xeroderma pigmentosum don't have the capacity to repair DNA that's been corrupted by UV radiation from the sun. Children with Xeroderma pigmentosum develop skin cancers. In the larger population, such cancers tend to occur much later in life. The reason, Samson says, is that most of us have a formidable array of mechanisms within our cells for detecting and mending defective DNA. Cells with flawed DNA that goes unrepaired must either die, or go on to mutate in often dangerous ways. Samson wants to figure out how to protect cells against carcinogenic effects in the environment, and whether a tumor cell will be susceptible to treatment. She has been painstakingly studying the Saccharomyces cerevisiae yeast organism, trying to identify all the factors that determine whether or not DNA damaging agents kill or mutate cells. She interrogated each of this organism's 5,800 genes, -asking one by one, which of you is making a product that's important to helping a cell recover from damage.” In what was a -huge surprise,” Samson learned that there are more than 2,000 gene products involved in helping a yeast cell repair itself, -from areas of the cell never suspected before for being important” in this way. Now Samson must elucidate the complex cellular pathways that -talk to each other” when DNA is damaged -- and figure out -how to extend to humans, ultimately.”

About the Speaker(s): Leona Samason became Director of the MIT Center for Environmental Health Sciences in 2001. She is also an Affiliate at the MIT Center for Cancer Research and an Adjunct Professor of Toxicology at the Harvard School of Public Health.

Her research aims at understanding how cell, tissues, animals and ultimately people respond upon exposure to environmental toxicants in general, and alkylating agents in particular. A wide variety of DNA repair pathways provide protection against DNA alkylation damage and it is now clear that a multitude of other pathways are important for cellular recovery. Samson's goal is to understand how these pathways function, how they are regulated, and how they integrate to determine the ultimate biological and health consequences of environmental exposures.

Samson received a B.Sc. in Biochemistry from Aberdeen University, Scotland in 1974, and her Ph.D. in Molecular Biology from the Imperial Cancer Research Fund and University College, London University, England, in 1978.

Host(s): School of Science, School of Science

Comments (0)

It looks like no one has posted a comment yet. You can be the first!

You need to log in, in order to post comments. If you don’t have an account yet, sign up now!

MIT World — special events and lectures

MIT World — special events and lectures

Category: Events | Updated over 2 years ago

Created
December 13, 2011 12:59
Category
Tags
License
All Rights Reserved (What is this?)
Additional Files


Viewed
2260 times

More from MIT World — special events and lectures

Kofi Annan Keynote Address

Kofi Annan Keynote Address

Added over 2 years ago | 00:39:50 | 1558 views

Expand Your Mind: Getting a Grasp on Consciousness

Expand Your Mind: Getting a Grasp o...

Added over 2 years ago | 01:44:00 | 1712 views

Challenges to the Global Economy

Challenges to the Global Economy

Added over 2 years ago | 01:12:00 | 4592 views

Knowledge Based Economy and Education: Changing Roles for Universities " The MIT Perspective

Knowledge Based Economy and Educati...

Added over 2 years ago | 00:35:34 | 1828 views

Climate Change: The Economics of and Prospects for a Global Deal

Climate Change: The Economics of an...

Added over 2 years ago | 01:10:00 | 1659 views

Plays Well With Others: Leadership in Online Collaboration

Plays Well With Others: Leadership ...

Added over 2 years ago | 00:37:49 | 10901 views