The idea of the CRISPR-Cas technique has been adapted from the bacterial immune
system. The CRISPR-Cas9 system has been widely adopted all over the world and
successfully applied to target essential genes in different organisms and cell lines,
including bacteria, zebrafish, monkeys, rabbits, mice, and even humans.
The first description of what would later be called CRISPR is from Osaka
University researcher Yoshizumi Ishino and his colleagues in 1987. They accidentally
cloned part of a CRISPR sequence together with the “iap” gene (isozyme conversion of
alkaline phosphatase) from the genome of Escherichia coli that was their target. The
organization of the repeats was unusual. Repeated sequences are typically arranged
consecutively, without interspersed different sequences. They did not know the function
of the interrupted clustered repeats. These intriguing discoveries motivated him to study
the phenomena further; in 2000, he named these structures short regularly spaced
repeats (SRSRs). Later, the name was changed to clustered regularly interspaced
palindromic repeats (CRISPR). 9 This vital finding helped scientists to hypothesize,
correctly, that CRISPR is an adaptive immune system.
Scientists all over the world are using the CRISPR-Cas9 system to address cancer treatment from different research perspectives
Bacterial CRISPR spacers are short, variable sequences derived from the genomes
of viruses that previously invaded the bacteria. Such sequences provide ‘genetic
memory’. During viral attacks, the CRISPR defense mechanism of bacteria shears viral
genome sequences analogous to spacer sequences.
Brain cancer is the most lethal among all cancers, regardless of gender and age. The
therapies used against brain cancers such as gliomas have been more or less the same
for the last five decades. There are also technical difficulties in the clinical
management of brain cancer. For these reasons, researchers are trying to find solutions
at the genetic level. In this context, CRISPR-Cas9 can be an efficient, convenient and
less time-consuming technique. There are four types of animal models used in the
study of gliomas and medulloblastomas of human brain cancer: patient-derived
xenograft (PDX), cell-derived xenograft (CDX), genetically engineered mouse and in
vivo mouse model.The Ptch1 gene responsible for medulloblastoma and the Trp53,
Pten and Nf1 genes accountable for glioblastoma can be knocked out in the mouse
brain using the CRISPR-Cas9 technique.
This technique can also be used in further
investigations against other regulatory genes found to be responsible for brain tumors.
Kaynakça:
https://www.britannica.com/technology/CRISPR-Cas9
Yazar:Anar Mammadov
