HOME >> BIOLOGY >> NEWS
Tiny tweezers and yeast help St. Jude show how cancer drug works

The annoying bulges of an over-wound telephone cord that shorten its reach and limit a callers motion help to explain why drugs called camptothecins are so effective in killing cancer cells, according to investigators at St. Jude Children's Research Hospital and Delft University of Technology.

Using a type of nanotechnology called magnetic tweezers as well as yeast cells, investigators showed that a camptothecin drug called topotecan kills cancer cells by preventing an enzyme, called DNA topoisomerase I, from uncoiling double-stranded DNA in those cells. Instead, the DNA becomes locked in tight twists, called supercoils, which bulge out from the side of the over-wound DNA moleculemuch like the bulges in an over-wound telephone cord. If these supercoils accumulate and persist while the cell is trying to separate the two strands of DNA to make exact copies of the chromosomes during cell division, the cells will die.

Nanotechnology studies work at a scale of about 100 nanometers or less. For comparison, one nanometer is approximately 10 times the size of an atom; and 10 nanometers is one-thousandth of the diameter of a human hair.

In this first-of-its-kind study, researchers used the microscopic magnetic tweezers to monitor changes in the length of an individual DNA molecule caused by the action of a single topoisomerase I enzyme; and to study how the binding of a single topotecan molecule to this enzyme-DNA complex alters DNA uncoiling. Based on the results of those studies, scientists developed the supercoil theory to explain the drugs ability to kill cancer cells, and then tested that theory in yeast cells. Their conclusionthat accumulation of DNA supercoiling kills the cellsprovides a novel model for how topotecan works; and it provides insights into the drugs action that could help scientists in the clinical development of these agents. A report on this work appears in the advanced, online issue of Nature.

This is the fi
'"/>

Contact: Summer Freeman
summer.freeman@stjude.org
901-495-3061
St. Jude Children's Research Hospital
9-Jul-2007


Page: 1 2 3 4

Related biology news :

1. Engineers create optoelectronic tweezers to round up cells, microparticles
2. Laser tweezers reveal microscopic mechanical properties of blood clots
3. Hives ferment a yeasty brew, attract beetle pest
4. Vitamin extends life in yeast, Dartmouth Medical School researchers find
5. Protein structures for the entire yeast proteome
6. Primitive yeast yields secrets of human cholesterol and drug metabolism
7. MIT: Engineered yeast speeds ethanol production
8. Engineered yeast speeds ethanol production
9. From a lowly yeast, researchers divine a clue to human disease
10. Potassium limitation, ammonium toxicity and amino acid excretion in yeast
11. Dartmouth and GlycoFi report full humanization of therapeutic proteins from yeast

Post Your Comments:
*Name:
*Comment:
*Email:


(Date:8/12/2020)... ... August 11, 2020 , ... ... in Princeton, NJ, have entered into license agreements with Housey Pharma’s HMI subsidiary ... Both Roche and J&J have annual Research and Development spending in excess of ...
(Date:8/5/2020)... ... 05, 2020 , ... Regenative Labs has received approval from the Centers for ... them the first Wharton’s jelly allografts to be assigned a Q code and be ... the first Wharton’s jelly allograft product to be recognized as a 361 HCT/P by ...
(Date:7/22/2020)... , ... July 21, 2020 , ... ... transformation and innovation in technology and compliance, announces a new solution to manage ... must ensure every layer of their technology stack complies with FDA and global ...
Breaking Biology News(10 mins):
(Date:7/31/2020)... (PRWEB) , ... July 29, 2020 , ... ... 200 of the top radiation centers in 16 countries, has reached its 20th ... SDX® is now in routine use at top universities including University of Pennsylvania, ...
(Date:7/22/2020)... ... 22, 2020 , ... Join experts from Reed Tech , Gary Saner, ... a one hour live webinar on Thursday, August 13, 2020 at 11am ... and medical devices. Specifically, for medical devices, the NMPA has departments dealing with medical ...
(Date:7/18/2020)... ... ... “We are thrilled to deliver this new technology to the industry” said ... on the market and we were pleased that the IFT jury recognized that.” reFRESH™ ... creating a natural way to extend the shelf life and improve the safety of ...
(Date:7/18/2020)... ... July 17, 2020 , ... dicentra ... life sciences and food industries, is pleased to announce that Charles Galea has ... Business Development. , Charles is an accomplished and results-driven sales executive with over ...
Breaking Biology Technology:
Cached News: