16, August 2014

Salt can kill cancer cells

The next weapon to effectively fight cancer could be salt as researchers have found that an influx of salt into a cell triggers its death.

The finding could lead to new anti-cancer drugs, said the researchers who created a molecule that can cause cancer cells to self-destruct by carrying sodium and chloride ions into the cells.

"This work shows how chloride transporters can work with sodium channels in cell membranes to cause an influx of salt into a cell," said study co-author professor Philip Gale from the University of Southampton in Britain.

"We found we can trigger cell death with salt," Gale added.

Cells in the human body work hard to maintain a stable concentration of ions inside their cell membranes.

Disruption of this delicate balance can trigger cells to go through apoptosis, known as programmed cell death, a mechanism the body uses to rid itself of damaged or dangerous cells.

Unfortunately, when a cell becomes cancerous, it changes the way it transports ions across its cell membrane in a way that blocks apoptosis.

The new synthetic ion transporter works by essentially surrounding the chloride ion in an organic blanket, allowing the ion to dissolve in the cell's membrane, which is composed largely of lipids, or fats.

The researchers found that the chloride transporter tends to use the sodium channels that naturally occur in the cell's membrane, bringing sodium ions along for the ride.

"We have shown that this mechanism of chloride influx into the cell by a synthetic transporter does indeed trigger apoptosis," said co-author of the study Jonathan Sessler from the University of Texas at Austin.

The study appeared in the journal Nature Chemistry.

Source: www.timesofindia.com

16.08.2014

HIV vaccine a step closer

Researchers have uncovered new properties of special HIV antibodies called "broadly neutralising antibodies" or BNAbs, a discovery that could shed light on the pathway the BNAbs take to develop and speed up development of HIV vaccine. 

Only a small subset of HIV-infected individuals produce BNAbs. 

A vaccine that works by eliciting BNAbs is, therefore, a major goal, and this work suggests that strategies for such a vaccine should focus on speeding up the antibody evolution that occurs after every immunisation. 

"This result suggests that a BNAb-eliciting vaccine is possible after all," said lead author Thomas Kepler, a professor of microbiology at Boston University School of Medicine in the US. 

Antibodies develop from immune cells known as B cells. When B cells are confronted with foreign elements (known as antigens), some of them experience a high rate of mutations resulting in the substitution of an amino acid within the antibody for another. 

When whole strings of amino acids are inserted or deleted, this is known as an indel. 

Less than four percent of human antibodies contain indels; in BNAbs this figure is more than 50 percent. 

The researchers studied one particular BNAb called CH31, which has a very large indel, to see what role these indels might have played in the acquisition of broad neutralising activity. 

They found that the indel was the key event in the development of CH31. 

Just putting the indel into antibodies that did not originally have it, increased its effectiveness eight-fold; taking it away from ones that did have it initially, made them much worse, the researchers said. 

"When tested on their ability to broadly neutralise HIV, only those CH31 antibodies with indels were able to accomplish the task," Kepler said. 

The study appeared in the journal Cell Host and Microbe.

Source: www.timesofindia.com

16.08.2014

We are judged by what we finish, not what we start