Diagnosis of cancer localization by blood analysis
American scientists create a test "for cancer"
Molecular biologists from the University of California at San Diego have developed a genetic test that can be used to diagnose cancer by pinpointing its localization, reports Infox.
The authors report on the results of their work in the latest issue of the journal Nature Genetics (Guo et al., Identification of methylation haplotype blocks aids in deconvolution of heterogenic tissue samples and tumor tissue-of-origin mapping from plasma DNA – VM).
As you know, there are currently no simple tests "for cancer". To diagnose cancer, complex diagnostic procedures are usually required. For example, the analysis of cells obtained as a result of a biopsy. It is a big misconception that by taking a blood test for cancer markers, you can detect cancer. In fact, cancer markers are used in complex diagnostics and do not mean anything by themselves.
Scientists have been searching for minimally invasive and convenient tests "for cancer" for a long time. It seems that in the current study, a group led by Dr. Kun Zhang managed to get closer to solving this problem.
As the authors explain (in the press release New blood test could help detect and locate cancer early on – VM), the test they developed is based on the detection in the blood of pieces of DNA of body cells that cancer cells have already destroyed, and which then got into the bloodstream. "When cancer cells begin to spread throughout the body, they compete for nutrients and for space with normal healthy cells. Often healthy cells die under the influence of cancer cells, and then their destroyed DNA gets into the blood," says Dr. Zhang.
In order to detect the DNA remnants of healthy cells and the places where the cells were destroyed, the scientists applied the method of analysis of CpG-methylation for different types of cancer and compared these data with CpG methylation in healthy people. As a result, they created a database for different types of cancer localization.
Methylation refers to the epigenetic mechanisms of DNA changes that often occur under the influence of certain environmental factors. This is a chemical change in DNA, which consists in "hanging" methyl groups on nitrogenous bases (methyl group (-CH3) to the nucleotide cytosine, C). Moreover, it is necessary that C be followed by the nucleotide guanine, G. The sequence of nucleotides -CG- is called the CpG dinucleotide, or CpG site.
DNA methylation is one of the important mechanisms for regulating gene expression. It is known that different types of cancer, diabetes of the first and second kind, schizophrenia, etc. are associated with changes in the methylation profile.
Of course, the authors add, they are only taking the first steps in developing a method for diagnosing cancer and its localization by blood, but, nevertheless, they really hope that this idea has a great future.
Portal "Eternal youth" http://vechnayamolodost.ru 07.03.2017