Washington, July 07: Make sure that your daily diet contains breads, beans, potatoes, rice and cereals, for a new study says that these foods that are high in carbohydrates act as tumour suppressors in breast and prostate cancers.
A team at Burnham Institute for Medical Research has discovered that specialised complex sugar molecules (glycans) which anchor cells into place suppressors tumours in breast and prostate cancers.
These glycans play a critical role in cell adhesion in normal cells, and their decrease or loss leads to increased cell migration by invasive cancer cells and metastasis.
An increase in expression of the enzyme that produces these glycans, Beta-3GnT1, resulted in a significant reduction in tumour activity, found the study published in latest issue of the Proceedings of the National Academy of Sciences journal.
The specialised glycans are capable of binding to laminin and attached to the ?-DG cell surface protein. This binding facilitates adhesion between epithelial and basement membrane cells and prevents cells from migrating.
“These results indicate that certain carbohydrates on normal cells and enzymes that synthesise those glycans, such as Beta-3GnT1, function as tumor suppressors. And, upregulation of Beta-3GnT1 may become a novel way to treat cancer,” Prof. Minoru Fukuda, who led the team, said.
In fact, in their study, the researchers showed that Beta-3GnT1 controls the synthesis of laminin-binding glycans in concert with the genes LARGE/LARGE2. Down-regulation of Beta-3GnT1 reduces the number of glycans, leading to greater movement by invasive cancer cells.
However, when they forced aggressive cancer cells to express Beta-3GnT1, the laminin-binding glycans were restored and tumour formation decreased.
Using antibodies, the team investigated the expression of both Alpha-DG and its associated glycans in both normal and cancerous cells. They found that the quantity of Alpha-DG was similar in both cell types, but the level of attached glycans was reduced in the cancer cells.
Further study showed that prostate cancer cells that highly expressed the Alpha-DG glycans produced smaller tumours.
The team found that when they knocked down Beta-3GnT1 expression by RNA interference, which reduces protein expression, the amount of glycans decreased even when LARGE was overexpressed.
The scientists demonstrated that Beta-3GnT1 plays a key role in forming laminin-binding glycans attached to Alpha-DG, which in turn reduces cancer cell movement.
–PTI