Artificial virus delivers genes and drugs to cancer cells
Natural viruses are very effective vectors – carriers of genes, however, when they enter the body, viral vectors are able to trigger immune reactions or cause the formation of tumors. Artificially synthesized viruses do not have such side effects, but have very limited effectiveness, due to the complexity of providing certain sizes and shapes during their synthesis, which are critical parameters of their effectiveness.
Korean scientists working under the guidance of Dr. Myongsoo Lee have developed a new strategy that allows synthesizing artificial viral vectors with strictly defined sizes and shapes.
As a template, the authors used ribbon protein structures (beta layers), which self-assemble into two-layer fibrous structures that determine the size and shape of the synthesized particle.
Protein molecules are attached to the outer surface of the synthesized particle, binding to short fragments of RNA (small interfering RNA, miRNA, siRNA) and enveloping them.
If these RNA fragments are complementary to a specific nucleotide sequence of the matrix RNA, they specifically block the synthesis of the corresponding protein. The use of miRNA is one of the most promising methods of gene therapy.
To facilitate the penetration of artificial viral particles into the cell, the researchers attached molecules to their surface that bind to glucose carriers located in the cell membrane. These transporters are found on the surface of almost all mammalian cells, and their particularly high concentration is characteristic of tumor cells.
Experiments on human cell lines have demonstrated the ability of artificial viruses to efficiently transport miRNA into cells and selectively block gene expression.
In addition, for demonstration purposes, the researchers were able to attach hydrophobic molecules to artificial viral particles. This allowed them to observe the movement of label molecules inside the nuclei of tumor cells. In the future, synthetic viruses can be used to deliver antitumor drugs to the nuclei of cancer cells.
Article by Yong-beom Lim et al. "Filamentous Artificial Virus from a Self-Assembled Discrete Nanoribbon" published in the 47th issue of the international edition of Angewandte Chemie.
Portal "Eternal youth" www.vechnayamolodost.ru based on the materials of ScienceDaily
04.06.2008