这个在国外已经有了报道:
Kamihira and his team connected a few genes to this promoter. One codes for tumor necrosis factor-α (TNF-α), a protein that induces cell death. Another gene codes for a protein that activates a second element in the circuit. This element keeps transcription of TNF-α going long after the heat开发者_如何学JAVA stimulus is gone. So after a pulse of external heat, a positive feedback loop turns on to continuously produce the cell-killing protein.http://cen.acs.org/articles/91 ... .html
To test the nanoparticle-gene circuit combination, the researchers inserted the promoter and genes into human lung cancer cells. They encased the DNA inside liposomes that fuse with the cells’ membranes and release the genetic information into the cell, where it can find the cell’s transcription machinery. Then they added magnetite nanoparticles coated in lipids, which also slipped inside the cells. When the researchers applied an alternating magnetic field for 30 minutes, the cells warmed to 43 °C, and 90% of them died. Heat from the nanoparticles alone also killed the cells, but not as effectively as when they were combined with the heat-triggered gene circuit. In fact, when the team examined cells containing the nanoparticles and a plasmid without any of the therapeutic genes four days later, only 60% of the cells exposed to the magnetic field were dead.
The researchers also tested their method in mice with tumors grown from injected human lung cancer cells. They also injected the gene-containing liposomes and magnetic particles into the tumor site. Some animals were exposed to an alternating magnetic field for 30 minutes; other mice were not. After 30 days, mice placed in the magnetic field had tumors that were just 8% of the volume of those in unexposed mice.
精彩评论