Researchers think they’ve hit upon a tricky way to stunt or even stop pleural mesothelioma cell growth. They’ve got a gene that tells the cancer to shut up when it comes to the expression of mesothelin.
Mesothelin is a protein contained in the healthy mesothelial cells that make up the lining of the chest and abdomen.
But scientists have noticed that mesothelin is overexpressed when the cells turn cancerous.
That led a group of researchers in Italy, the United Kingdom and Japan to test a variant of the gene RNA against mesothelial cells overexpressing mesothelin.
The gene is called small interfering RNA — siRNA, for short. It’s also known as a silencing gene.
What silencing genes do is cause certain cells to pipe down. Or, to be more technical, they cause certain cells to be either down-regulated or entirely suppressed.
One of the ideas contained in this particular research team’s silencing concept is that healthy cells can be prevented from overexpressing mesothelin.
The researchers are of the opinion that if mesothelin is not overexpressed, the cells producing it won’t become cancerous. Or, if they already are cancerous, they’ll stop posing a deadly threat.
But that’s just theory. And it could remain a theory for some time to come because the way that RNA silencing works is not very well understood.
All anyone really knows is that there are various mechanisms involved in controlling and regulating gene expression, and that siRNAs are one of them.
They also know that induced RNA silencing allows gene functioning to be switched on or off by repressing the translation of genes into proteins.
A Promising Mesothelioma Treatment
The gene-silencing research team making a lot of noise with this study was mainly from the University of Pisa and the Laboratory of Clinical Oncology in Vercelli, both in Italy.
Joining them for the project were investigators from Imperial College in London and Kansai Medical University in Osaka, Japan.
Their work was published earlier this year in the online journal PLOS ONE. They are looking into mesothelin expression in three strains of malignant pleural mesothelioma cells – NCI-H28, Mero-14, and IstMes2.
The researchers explained that they conducted what are known as “knock-down” experiments on samples of these three cell types that were overexpressing cells mesothelin.
Manually Programming the Apoptosis Switch
The experiments involved bringing these cells into contact with siRNA genes. The research team was encouraged by what it observed.
For example, there was a decrease in rate at which the mesothelin cells multiplied. The reason for the decrease was that RNA silencing caused these cells to die off.
It made this happen by turning on their apoptosis switch. Apoptosis is the built-in program that instructs a cell to kill itself in the event its internal machinery goes haywire for whatever reason.
Ordinarily, the apoptosis switch is automatically tripped when a healthy cell is in some way damaged.
But when a cell becomes cancerous, it gains the ability to block automatic apoptosis.
If you want the cell to kill itself, you’ve got to figure out a way to start the apoptosis program manually.
The researchers are now convinced that the RNA silencing could be the way to do just that.
“Our findings confirm that mesothelin should be considered a key molecular target for novel gene-based targeted therapies of cancer,” they concluded.