The mechanism used by Notch to regulate Myc in B cells is distinct from the mechanism
used in other cell types, such as T cells, where Notch also regulates Myc.
They found that,
unlike in other cell types where Xist is associated tightly with the inactive X chromosome, female lymphocytes lacked this Xist «cloud,» even though the cell still contained expected levels of Xist.
Further examinations of the inactive X in lymphocytes found that it lacked the heterochromatic marks found on the inactive
X in other cell types.
As Notch appears to use cell type - specific machinery to regulate Myc, it may be possible to target the Notch - Myc signaling path in a way that does not disrupt this
path in other cell types.
For example, these findings can accelerate the progress of gene - editing research because DNA repair profiling in one cell type may accurately predict repair
outcomes in other cell types, including human primary cells.
4 - 1BB can furthermore promote expression of survival proteins in T cells, although its
activities in other cell types appear to vary depending on the cell and the primary function.
«The ability to direct a gene to a specific cell type and prevent
expression in other cell types is a powerful new tool that allows us to bypass one of the most troubling safety concerns facing gene therapy,» said Michael Parmacek, MD, assistant professor of medicine at the University of Chicago and director of the study.
Importantly, this mix of molecular attributes is not known to
exist in any other cell type in the body and is likely to be a critical specialization for determining fluid flow into the canal.
They are also resistant to the viruses researchers
use in other cell types to deliver DNA instructions about how to build the machinery needed for CRISPR / Cas9 gene editing.
Xist (in pink), an RNA molecule responsible for inactivating one of a female's two X chromosomes, is not tightly associated with the X chromosome in healthy human female lymphocytes, though it is
in other cell types.
«The silencing of the X chromosome doesn't seem to be as tight in them as it is
in other cell types.»
For example, heart genes needs only to be turned on in heart cells, but turned off
in other cell types.
As an illustration, let us say that the 20 marker genes are only correlated in their respective cell type, and
in the other cell type they only correspond to random noise.