The
international race to bring human genome editing into widespread use in
clinical medicine is moving fast. On Jan 23, the National Institutes of
Health Common Fund launched its Somatic Cell Genome Editing programme,
committing approximately US$190 million of funding over the next 6
years to propel development of genome editing into medical practice. A
worthy effort, but the USA and Europe still trail behind China. As many
as 86 patients in China have already had their genes altered as part of
clinical trials to treat a range of diseases, including solid cancers.
Findings from these studies are yet to be reported in peer-reviewed
journals. Worryingly, serious criticisms have been levelled at China for forging ahead with these trials without sufficient regulatory review.
Investigators
of first in-human genome editing clinical trials in the USA and Europe
have applied to the US Food and Drug Administration and the European
Medicines Agency, respectively, to begin enrolling patients this year.
Originally planned to start in 2016, these studies have, in part, been
hampered by regulatory and safety concerns. Concerns that
are by no means unwarranted—as the technology advances, questions about
safety will undoubtedly be raised. A study
published on the bioRxiv preprint server this year showed pre-existing
adaptive immunity against bacterial-derived Cas9 in human serum, which
could result in patients having immune reactions against the
gene-editing machinery. Additionally, although all trials so far
registered modify genes ex vivo in cells that are then reintroduced into
patients, the next logical step is directly editing genes in vivo. A 2017 report
of an animal study using an in vivo CRISPR/Cas9 system showed an
unexpected number of off-target mutations, an important signal that
further research is needed before in vivo gene editing techniques can be
introduced into humans.Human genome editing is no
longer a concept confined to the pages of futuristic science fiction
novels—modifying genetic code is here now and is advancing rapidly.
Globally, regulators and investigators must work together to ensure
oversight of the development of gene editing technologies. Regulations
must not only keep up and anticipate future applications, but also
facilitate swift and safe implementation of the technology in the clinic. https://www.biorxiv.org/content/early/2018/01/05/243345
(PS. Tulee mieleen analogisesti ubikitiini, onkohan se jokin vanha eliö, olio, bakteeri, kun sillä on propeptidi 9 toistosekvenssiä 9x76, ja sellainen syöjäproteosomihahmo kuuluu sen järjestelmään jolla on kuin pää ja häntä, mutta olion hienontamat tuotteet hyödynnetään kehomiljöössä
Ubikitiinin esiproteiinista tulee 9 kpl monoubikitiiniä) Ihmiskeho on ottanut sen hyötykäyttöön ja se on hyvin monipuolinen värkki: Niitä osasia voi asettaa peräkkäin tai vierekkäin tilanteen mukaan vahventaen antivirusvastetta).
CRISPR/Cas9 comes from strep bacteria...
CRISPR is actually a naturally-occurring, ancient defense mechanism found in a wide range of bacteria. As far as back the 1980s, scientists observed a strange pattern in some bacterial genomes. One DNA sequence would be repeated over and over again, with unique sequences in between the repeats. They called this odd configuration “clustered regularly interspaced short palindromic repeats,” or CRISPR.This was all puzzling until scientists realized the unique sequences in between the repeats matched the DNA of viruses—specifically viruses that prey on bacteria. It turns out CRISPR is one part of the bacteria’s immune system, which keeps bits of dangerous viruses around so it can recognize and defend against those viruses next time they attack. The second part of the defense mechanism is a set of enzymes called Cas (CRISPR-associated proteins), which can precisely snip DNA and slice the hell out of invading viruses. Conveniently, the genes that encode for Cas are always sitting somewhere near the CRISPR sequences.
https://www.nature.com/articles/srep37895
Article
|
Open
A CRISPR-Cas9 Assisted Non-Homologous End-Joining Strategy for One-step Engineering of Bacterial Genome
- Scientific Reports volume 6, Article number: 37895 (2016)
- doi:10.1038/srep37895
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