DNA nanomachines against cancer
ITMO offered to treat cancer with nanomachines
Ivan Ortega, "The Attic"
An international group of scientists with the participation of researchers from ITMO proposed to treat cancer with DNA nanomachines. Previously, all attempts to treat this disease with gene therapy methods did not bring practical success.
From the very beginning of the very possibility of manipulating human genes, this method seemed to be a very attractive option for fighting cancer. Since a cancer cell is just a mutated human cell whose DNA has deviated from the norm, it seems logical to try to bring them back to normal. If not even complete, then at least relative, when a cell with "errors" in the DNA will have apoptosis, cell death. Alas, all attempts at direct gene therapy of tumor cells have not yielded practical results. There were three types of reasons: firstly, all available gene therapy tools have low selectivity (that is, they often try to manipulate the genes of healthy cells), secondly, they show little effectiveness in manipulating the genes themselves in a cancer cell, and thirdly, the folded DNA of cancer cells is often too complex an object for existing ones, there are still enough primitive means of genetic manipulation.
The authors of the new work (article Kolpashchikov et al. Towards DNA Nanomachines for Cancer Treatment: Achieving Selective and Efficient Cleavage of Folded RNA published in Angewandte Chemie) proposed and tried to experimentally test a fundamentally different approach – to create nanomachines working with cell DNA, implementing them based on enzymatic RNA as an active "corrective" nanomachine parts. In their concept, the nanomachine must first recognize a sequence of nucleotides that is a biomarker of cancer cells, and then contact this sequence with the help of microRNA and almost immediately cut it out with high efficiency (that is, in the vast majority of cases).
Illustration: IFMO/SCAMT
Then they assembled and tested such a nanomachine in practice, using several types of oligonucleotides in an aqueous salt solution, first heated to 95 ° C, and then cooled to room temperature in 12 hours. During this time, oligonucleotides by self-assembly created the basis for DNA nanomachines. The cutting part of the nanomachine was assembled on the basis of RNA-20 or RNA-46 sequences, often used for cutting out certain genes in the laboratory. The researchers also tested the toxicity of such compounds for ordinary cells and received encouraging results – it turned out to be extremely low.
It should be noted that the authors did not conduct a full cycle of experiments on cutting out the gene sequence from cancer cells – it was only shown that their nanomachine can cut out certain gene sequences in more than 50% of cases for a separate laboratory culture of cancer cells. Experiments on living beings were also not carried out. However, for the first work with a new nanomachine, the results look quite encouraging – the principle itself is shown, which allows editing cancer cell genes in the right way, as well as the practical methodology for implementing this principle.
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