In molecular biology, mir-145 microRNA is a short
RNA
Ribonucleic acid (RNA) is a polymeric molecule that is essential for most biological functions, either by performing the function itself (non-coding RNA) or by forming a template for the production of proteins (messenger RNA). RNA and deoxyrib ...
molecule that in humans is encoded by the MIR145
gene
In biology, the word gene has two meanings. The Mendelian gene is a basic unit of heredity. The molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protei ...
.
MicroRNA
Micro ribonucleic acid (microRNA, miRNA, μRNA) are small, single-stranded, non-coding RNA molecules containing 21–23 nucleotides. Found in plants, animals, and even some viruses, miRNAs are involved in RNA silencing and post-transcr ...
s function to regulate the expression levels of other genes by several mechanisms.
[
]
Targets
MicroRNAs are involved in down-regulation of a variety of target genes. Götte ''et al''. have shown that experimental over-expression of mir-145 down-regulates the junctional cell adhesion molecule
JAM-A as well as the actin bundling protein fascin in
breast cancer
Breast cancer is a cancer that develops from breast tissue. Signs of breast cancer may include a Breast lump, lump in the breast, a change in breast shape, dimpling of the skin, Milk-rejection sign, milk rejection, fluid coming from the nipp ...
and
endometriosis
Endometriosis is a disease in which Tissue (biology), tissue similar to the endometrium, the lining of the uterus, grows in other places in the body, outside the uterus. It occurs in women and a limited number of other female mammals. Endomet ...
cells, resulting in a reduction of
cell motility
Motility is the ability of an organism to move independently using metabolism, metabolic energy. This biological concept encompasses movement at various levels, from whole organisms to cells and subcellular components.
Motility is observed in ...
.
Larsson ''et al''.
showed that miR-145 targets the 3' UTR of the
FLI1
Friend leukemia integration 1 transcription factor (FLI1), also known as transcription factor ERGB, is a protein that in humans is encoded by the ''FLI1'' gene, which is a proto-oncogene.
Function
Fli-1 is a member of the ETS transcription fa ...
gene, a finding that was later supported by Zhang ''et al''.
Role in cancer
miR-145 is hypothesised to be a
tumor suppressor
A tumor suppressor gene (TSG), or anti-oncogene, is a gene that regulates a cell (biology), cell during cell division and replication. If the cell grows uncontrollably, it will result in cancer. When a tumor suppressor gene is mutated, it results ...
.
miR-145 has been shown to be down-regulated in
breast cancer
Breast cancer is a cancer that develops from breast tissue. Signs of breast cancer may include a Breast lump, lump in the breast, a change in breast shape, dimpling of the skin, Milk-rejection sign, milk rejection, fluid coming from the nipp ...
.
miR-145 is also involved in colon cancer
and
acute myeloid leukemia
Acute myeloid leukemia (AML) is a cancer of the myeloid line of blood cells, characterized by the rapid growth of abnormal cells that build up in the bone marrow and blood and interfere with haematopoiesis, normal blood cell production. Sympt ...
.
References
Further reading
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External links
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{{miRNA precursor families
MicroRNA
Tumor suppressor genes