microRNA
controls gene expression mainly by binding with messenger RNA (mRNA) in the cell cytoplasm
. Instead of being translated quickly into a protein, the marked mRNA will be either destroyed and its components recycled, or it will be preserved and translated later.
Why is miRNA important?
miRNAs have
key roles in the regulation of distinct processes in mammals
. They provide a key and powerful tool in gene regulation and thus a potential novel class of therapeutic targets. miRNAs play an evolutionarily conserved developmental role and diverse physiological functions in animal.
What is the function of microRNA?
MicroRNAs (miRNAs) are a class of non-coding RNAs that play important roles
in regulating gene expression
. The majority of miRNAs are transcribed from DNA sequences into primary miRNAs and processed into precursor miRNAs, and finally mature miRNAs.
How does microRNA therapy work?
MicroRNAs: Tiny master regulators
They
regulate gene expression by either degrading or making the targeted mRNAs “silence” rendering their translation into proteins
. The miRNAs regulate gene expressions, which affect various biological processes such as cell proliferation, differentiation, survival, and motility.
How does miRNA cause cancer?
MiRNAs may function as either oncogenes or tumor suppressors under certain conditions. The dysregulated miRNAs have been shown to affect the hallmarks of cancer, including
sustaining proliferative signaling, evading growth suppressors, resisting cell death, activating invasion and metastasis, and inducing angiogenesis
.
How is gene silencing done?
That is, a gene which would be expressed (turned on) under normal circumstances is switched off by machinery in the cell. Gene silencing is done by
incorporating the DNA to be silenced into a form of DNA called heterochromatin that is already silent
.
Do bacteria have miRNA?
As masters of genome-wide regulation, miRNAs represent a key component in the complex architecture of cellular processes. … Currently,
only a limited number of miRNA and miRNA-like
RNAs have been found in bacteria and viruses, a number that is sure to increase rapidly in the future.
What causes miRNA?
These alterations can be caused by a variety of mechanisms, including deletions, amplifications or
mutations involving microRNA loci
, by epigenetic silencing or by dysregulation of transcription factors targeting specific microRNAs.
How many miRNA do humans have?
There are now
over 2000 miRNAs
that have been discovered in humans and it is believed that they collectively regulate one third of the genes in the genome. miRNAs have been linked to many human diseases and are being pursued as clinical diagnostics and as therapeutic targets.
Are miRNA stable?
While RNA molecules are known to be highly unstable, previous studies have indicated that miRNAs
are remarkably stable in plasma and serum
, and resistant to RNase activity, as well as extreme pH and multiple numbers of freeze-thaw cycles [2,16,17].
Is microRNA gene therapy?
Combining miRNA regulation with gene therapy allows targeted and potent expression of transgenes. Such ‘de-targeting’ strategies incorporate miRNA target sites in the 3′ UTR of the therapeutic transgene, preventing its expression in cells that express the corresponding miRNA.
What is microRNA therapy?
MicroRNA (miRNA)-based therapeutics can be divided into miRNA
mimics and inhibitors of miRNAs
(also known as antimiRs). miRNA mimics are synthetic double-stranded small RNA molecules that match the corresponding miRNA sequence and therefore functionally aim to replenish the lost miRNA expression in diseases.
Is miRNA an oligonucleotide?
miRNAs belong to the
heterogenous family
of small endogenous non coding RNAs that also include small nucleolar RNA (snoRNA) and small interfering RNA (siRNA). The coding regions for miRNAs lie usually in the regions historically called “junk DNA”.
How does miRNA silence gene expression?
miRNAs (microRNAs) are short non-coding RNAs that regulate gene expression post-transcriptionally. They generally bind to the 3′-UTR (untranslated region) of their target mRNAs and repress protein production
by destabilizing the mRNA and translational silencing
.
How is miRNA regulated?
miRNA biogenesis is regulated at multiple levels, including at the level of
miRNA transcription
; its processing by Drosha and Dicer in the nucleus and cytoplasm, respectively; its modification by RNA editing, RNA methylation, uridylation and adenylation; Argonaute loading; and RNA decay.
Where does the name miRNA come from?
Mirna (Croatian/Mirna Serbian/Мирна) is a female name common among Croats and Serbs.
Derived from the Slavic element mir
, Mirna means “peaceful.” It is often confused with the name ‘Myrna’ (/myrrhna/), which is not Slavic in origin, but Celtic and means “beloved”, also “tender”.
