Page URL:

Probe developed to view human quadruple-stranded DNA

18 January 2021
Appeared in BioNews 1079

A new method for visualising quadruple-stranded DNA within living cells has been developed, shedding light on its potential functions and interactions.

DNA, which normally exists in its famous double-stranded helix formation, was first observed in living cells in its four-stranded state, known as a G-quadruplex, last year (see BioNews 1057). However, these new probes reveal molecules that interact with G-quadruplexes inside living cells, potentially alluding to drug targets that disrupt their activity.

'Evidence has been mounting that G-quadruplexes play an important role in a wide variety of processes vital for life, and in a range of diseases, but the missing link has been imaging this structure directly in living cells' said Ben Lewis, who was lead author of the study. He also described the problem as 'like finding a needle in a haystack, but the needle is also made of hay'.

As G-quadruplexes are found in higher concentrations in cancer cells, they are thought to be involved in the progression of the disease, providing a potential target for novel cancer therapies.

To explore this, the researchers at Imperial College London developed a chemical probe called DAOTA-M2, which fluoresces when G-quadruplexes are present. Then, by analysing how the length of fluorescence, and therefore the amount of G-quadruplex, changes depending on the other molecules present, they could shed light on their potential roles and interactions within the cell.

Dr Marina Kuimova, one of the leads of the study, said that 'by applying this more sophisticated approach we can remove the difficulties which have prevented the development of reliable probes for this DNA structure.'

The researchers showed that G-quadruplexes interact with proteins called helicases, which are responsible for 'unwinding' DNA and beginning their breakdown. They also tested how other molecules interacted with G-quadruplexes, which may aid in the design of drugs for cancer treatment.

'Many researchers have been interested in the potential of G-quadruplex binding molecules as potential drugs for diseases such as cancers' said Professor Roman Vilar, who also co-led the study. 'Our method will help to progress our understanding of these potential new drugs.'

Rare four stranded DNA has been observed in action for the first time
Science Alert |  12 January 2021
Rare quadruple-helix DNA found in living human cells with glowing probes
Imperial College London |  8 January 2021
Scientists found a rare quadruple-helix DNA in living human cells
Tech Explorist |  8 January 2021
Visualising G-quadruplex DNA dynamics in live cells by fluorescence lifetime imaging microscopy
Nature Communications |  8 January 2021
13 December 2021 - by Paige Mumford 
A protein that is known to be affected in people with the rare ageing disease Cockayne syndrome, has been shown to interact with four-stranded DNA...
5 July 2021 - by Dr George Janes 
Quadruple-stranded DNA structures appear to be evolutionarily conserved in some regions of the genome, indicating they serve an important purpose...
10 May 2021 - by Martha Roberts 
A 'chemical nose' can detect the quadruple-stranded DNA associated with diseases such as cancer...
22 February 2021 - by Joseph Hamilton 
'Dancing' DNA, imaged at the highest ever resolution, offers new genetic insight for the development of cancer therapies...
27 July 2020 - by Daniel Jacobson 
Quadruple-stranded DNA has been observed in healthy human cells for the first time, shedding light on its possible role in cancer...
19 August 2019 - by Eleanor Taylor 
If you asked me to describe how DNA was discovered, I would probably begin by recounting how Francis Crick and James Watson successfully identified the three-dimensional structure of DNA at the University of Cambridge, in 1953, and end my explanation by discussing the role that Rosalind Franklin played in this momentous scientific breakthrough...
12 August 2019 - by Eleanor Mackle 
So, you think Watson and Crick discovered DNA? I did too, until I attended a talk by Professor Gareth Williams at the Royal Institution, called 'Unravelling the Double Helix'...
30 April 2018 - by Dr Rachel Huddart 
A 'twisted knot' of DNA, known as an i-motif, has been found in living cells for the first time, raising questions about its function...
to add a Comment.

By posting a comment you agree to abide by the BioNews terms and conditions

Syndicate this story - click here to enquire about using this story.