Now a blood test for brain tumour
Brain tumours of the kind that are cancerous can now be easily detected through a simple blood test, much before it is too late for the doctors to do anything about them.
At the Indian Institute of Science, a clutch of scientists have discovered an easier and cost-effective way to determine the presence of the tumour, known as glioblastoma in medical parlance.
Glioblastoma (GBM) is the most malignant type of tumour and also highly prevalent in men typically aged above 50. Its detection usually happens at a late stage, through diagnostic tests like a CT scan or MRI, and from then the chances of survival extend only upto 15 months or so.
The newly found blood test can not just help diagnose the disease in an easier way, but also targets the treatment in such a way that it improves survival chances.
In this test, blood is allowed to clot to derive serum, a transparent liquid portion. Presence of three kinds of proteins is then assessed, as they have different levels in glioblastoma patients.
One of the proteins, called the C-reactive protein (CRP), is higher in brain tumour patients than in normal samples; the two other proteins - LYAM1 and BHE40 - are at a much lower level, according to a research paper that appeared in the Journal of Proteomics last month.
“Looking at the levels of these three proteins in the serum, we can predict with 90% accuracy whether the individuall has the tumour or not,” said Mamatha Nijaguna, who is a part of the team which conducted this study. The protein (CRP) is chemically made by the liver cells and not brains cell. “This finding intrigued us to know more,” she said.
The team of researchers then found that the cells in the brain tumor were secreting a molecule in the blood, which reaches the liver, demanding that it secrete higher levels of CRP.
“Our results also show that this protein is not promoting cell division, migration, or drug resistance in tumour cells back in the brain. These traits are the ‘hallmarks’ of cancer. After reaching the brain via circulation it asks the brain cells, the ones responsible for instructing the immune defence of the nervous system, to produce another protein which promotes the survival of GBM,” said Prof Kumar Somasundaram who led the study and is a professor at the Department of Microbiology and Cell Biology, IISc.
Researchers were also surprised to learn through the study that tumours can communicate with normal cells, instructing them to behave in a fashion that encourages their growth.
“Cancer is a bundle of uncontrollably fast-dividing cells; such fast division requires nutrients and oxygen, and therefore cancer needs more blood vessels directly feeding into it all the time. That might explain why GBM patients have higher CRP levels,” Somasundaram said. Higher CRP levels also are associated with a shorter survival period after diagnosis.
Understanding how the protein is present in the serum can be cost-effective and minimally invasive, as serum can be made easily available by drawing small amount of blood. “Future progress in this pipeline can help early diagnosis, better targeted therapies, and eventually longer survival and lower mortality rates,” Nijaguna said.