MALAT 1 (metastasis associated lung adenocarcinoma transcript 1) also known as NEAT2 (noncoding nuclear-enriched abundant transcript 2) is a large, infrequently
spliced
Spliced may refer to:
*Spliced, the result of rope splicing
Rope splicing in ropework is the forming of a semi-permanent joint between two ropes or two parts of the same rope by partly untwisting and then interweaving their strands. Splices ca ...
non-coding RNA
A non-coding RNA (ncRNA) is a functional RNA molecule that is not translated into a protein. The DNA sequence from which a functional non-coding RNA is transcribed is often called an RNA gene. Abundant and functionally important types of non-c ...
, which is highly conserved amongst
mammals
Mammals () are a group of vertebrate animals constituting the class Mammalia (), characterized by the presence of mammary glands which in females produce milk for feeding (nursing) their young, a neocortex (a region of the brain), fur or ...
and highly expressed in the
nucleus
Nucleus ( : nuclei) is a Latin word for the seed inside a fruit. It most often refers to:
*Atomic nucleus, the very dense central region of an atom
*Cell nucleus, a central organelle of a eukaryotic cell, containing most of the cell's DNA
Nucle ...
.
[ ] MALAT1 was identified in multiple types of physiological processes, such as alternative splicing, nuclear organization, epigenetic modulating of gene expression, and a number of evidences indicate that MALAT1 also closely relate to various pathological processes, ranging from diabetes complications to cancers.
It regulates the
expression
Expression may refer to:
Linguistics
* Expression (linguistics), a word, phrase, or sentence
* Fixed expression, a form of words with a specific meaning
* Idiom, a type of fixed expression
* Metaphorical expression, a particular word, phrase, o ...
of
metastasis
Metastasis is a pathogenic agent's spread from an initial or primary site to a different or secondary site within the host's body; the term is typically used when referring to metastasis by a cancerous tumor. The newly pathological sites, then, ...
-associated
genes
In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a ba ...
. It also positively regulates
cell
Cell most often refers to:
* Cell (biology), the functional basic unit of life
Cell may also refer to:
Locations
* Monastic cell, a small room, hut, or cave in which a religious recluse lives, alternatively the small precursor of a monastery ...
motility via the
transcriptional
Transcription is the process of copying a segment of DNA into RNA. The segments of DNA transcribed into RNA molecules that can encode proteins are said to produce messenger RNA (mRNA). Other segments of DNA are copied into RNA molecules calle ...
and/or post-transcriptional regulation of motility-related genes.
MALAT1 may play a role in
temperature-dependent sex determination Temperature-dependent sex determination (TSD) is a type of environmental sex determination in which the temperatures experienced during embryonic/larval development determine the sex of the offspring. It is only observed in reptiles and teleost fish ...
in the Red-eared slider turtle (''
Trachemys scripta
The pond slider (''Trachemys scripta'') is a species of common, medium-sized, semiaquatic turtle. Three subspecies are described, the most recognizable of which is the red-eared slider (''T. s. elegans''), which is popular in the pet trade and ha ...
'').
Expression in alcoholic brains
Transcripts of MALAT1 are significantly increased in the
cerebellum
The cerebellum (Latin for "little brain") is a major feature of the hindbrain of all vertebrates. Although usually smaller than the cerebrum, in some animals such as the mormyrid fishes it may be as large as or even larger. In humans, the cerebel ...
of human alcoholics, as well as in similar regions of rat brains after the withdrawal of ethanol vapours. This alcohol-induced upregulation of MALAT1 may be responsible for differential expression of a number of proteins which contribute to ethanol tolerance and dependency in humans.
Prognostic potential in cancer
The implication of MALAT1 RNA in the pathology of various cancers has been documented.
Elevated MALAT1 expression is correlated with poor overall survival in various types of cancer, suggesting that this gene is a prognostic factor for different types of cancer.
As a target for the treatment of cancer
Genetic loss or systemic knockdown of Malat1 using
antisense oligonucleotides (ASO) in the mouse mammary carcinoma model results in slower tumor growth accompanied by significant differentiation into cystic tumors and a reduction in metastasis. At the molecular level, the ASO-Malat1 hybrid stimulates a naturally occurring cellular enzyme that degrades the Malat1 lncRNA. Malat1 knockdown results in alterations in gene expression and changes in splicing patterns of genes involved in differentiation and protumorigenic signaling pathways. Metastatic tumors have a dependency on Malat1—they can't thrive without it. And very importantly, only the cancer cells seem to require it. In so far as MALAT1 has been identified to be involved in tumorigenesis of various types of cancer such as lung cancer, pancreatic cancer, cervical cancer Malat1 ASOs represent a potential therapy for inhibiting such cancers progression.
See also
*
Long non-coding RNA
Long non-coding RNAs (long ncRNAs, lncRNA) are a type of RNA, generally defined as transcripts more than 200 nucleotides that are not translated into protein. This arbitrary limit distinguishes long ncRNAs from small non-coding RNAs, such as mic ...
*
MALAT1-associated small cytoplasmic RNA
MALAT1-associated small cytoplasmic RNA, also known as mascRNA, is a non-coding RNA found in the cytosol. This is a small RNA, roughly 53–61 nucleotides in length, that is processed from a much longer ncRNA called MALAT1 by an enzyme called RNas ...
References
Further reading
*
*
*
*
*
*
*
*
*
*
*
*
External links
OMIM page for MALAT1HGNC page for MALAT1* {{Rfam, id=RF01871, name=Metastasis associated lung adenocarcinoma transcript 1
Relevance of MALAT1 in single-cell RNA sequencing data
Non-coding RNA