New Colon Cancer culprit found, a protein

Now, a team of researchers from the University of Pennsylvania has found evidence of a new culprit in the disease, a protein called MSI2. Their findings provide a new target for potential therapeutic intervention in colorectal cancer and enhance our understanding of the complexities of cancer initiation and progression. Further studies of MSI2 may even help explain how the disease can return after lying dormant for years.
In earlier studies, Lengner and Kharas had found that an RNA binding protein called MSI2 played a role in supporting the potency of hematopoietic stem cells. This same protein was also found to be highly active in blood cancers. Yet unlike other well-established genes that, when mutated, result in increased tumor formation, the MSI2 gene itself is not directly mutated in tumors. Rather, the normal, intact gene becomes highly activated as cancer progresses.
When MSI2 is active, the protein promotes cancer not by changing the expression of genes but by altering the ability of RNA to make proteins. Until now, the contribution of MSI2 went undetected by traditional research techniques that are largely aimed at identifying mutations in DNA sequence and alterations in gene expression patterns.
Instead, in the current work, the Penn-led team performed an analysis to look for RNA transcripts that were highly expressed in cancerous tissues but not in normal tissue. They found over-expression of MSI2 was a common characteristic of colon cancer tumors.
Next, they used colorectal cancer cell lines to experimentally block MSI2 activity and found the growth of the tumors was strongly inhibited, another sign that MSI2 promotes cancer growth.