Mir-129 microRNA precursor family

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mir-129 microRNA precursor family
RF00486.jpg
Predicted secondary structure and sequence conservation of mir-129
Identifiers
Symbolmir-129
Rfam RF00486
miRBase MI0000252
miRBase family MIPF0000073
Other data
RNA type Gene; miRNA
Domain(s) Eukaryota
GO GO:0035195 GO:0035068
SO SO:0001244
PDB structures PDBe

The miR-129 microRNA precursor is a small non-coding RNA molecule that regulates gene expression. This microRNA was first experimentally characterised in mouse [1] and homologues have since been discovered in several other species, such as humans, [2] rats [3] and zebrafish. [4] The mature sequence is excised by the Dicer enzyme from the 5' arm of the hairpin. It was elucidated by Calin et al. that miR-129-1 is located in a fragile site region of the human genome near a specific site, FRA7H in chromosome 7q32, which is a site commonly deleted in many cancers. miR-129-2 is located in 11p11.2. [5]

Contents

Expression Patterns

miR-129 seems to have a tissue specific expression pattern localised to the brain in normal humans. This finding was identified initially by microarray experimentation with mouse tissue (and more specifically to the cerebellum) [1] which was subsequently validated by the expression profiling in human tissue. However, expression in normal brain tissue was found to be relatively low and different profiling experimentation methodologies produced differing results. These differences and the low levels of detection may be attributed to the size and complexity of the human brain and the fact that specific regions of the brain were not individually tested. [6]

Targets of miR-129

Cdk6

As with many other microRNAs, the expression profile of miR-129 changes with the onset of cancer. In many different tumour cell lines, such as gastric cancer, medulloblastoma and endometrial cancer, lung andeocarcinoma and colorectal carcinoma, there are lower levels of miR-129 indicating that it may play a role in the suppression of cell growth. There is evidence to suggest that miR-129 directly targets Cdk6, cyclin dependant kinase 6- a cell proliferation regulator. This is due to the effects of the down regulation of miR-129 in cancer cells resulting in their proliferation. Conversely in the over expression of miR-129, proliferation of endometrial tumour cells is significantly reduced via the down regulation of Cdk6. [7]

SOX4

SOX4, SRY-related HMG box 4 gene – an oncogene that is known to be deregulated in a number of cancers, is another target of miR-129 in which the aberrant regulation of miR-129 contributes to the proliferation of cancer cell lines. SOX4 is involved in the mediation of transcription response to Wnt signalling. In endometrial cancers and gastric cancers, there has been a clear link established between the epigenetic repression, or loss, of miR-129 and the over-expression of SOX4. In experiments where miR-129 levels were returned to normal in cancer cells, SOX4 expression was down regulated. Further, it has been suggested that promoter hypermethylation of miR-129-2 is the main contributor of SOX4 over expression in some types of cancer. [8] [9]

GALNT1

GALNT1, N-acetylgalactosaminyltransferase 1 – involved in TGF-β signalling, is another target of miR-129 that was identified by luciferase assay. It was observed that when cancer cells were subjected to transfection with the precursor of miR-129, GALNT1 was subsequently down regulated by the direct targeting of miR-129. The SOX4 target observation was also validated in this study. These results correlate with the notion that high levels of miR-129 and low SOX4 and GALNT1 levels correlate to cancer cell progression. [10]

APC and Rab11

Adenomatous polyposis coli (APC), a tumour suppressor gene controlled by Wnt signalling and involved in proliferation, and Rab11 have also been identified as miR-129 targets from a RT-PCR experiment of the expression profiles of human esophageal squamous cell carcinoma (ESCC) . This study shows the over expression of miR-129 may play a part in the development of ESCC. This may be due to the possible suppression of signal transduction pathways via APC and Rab11. [11]

EIF2C3 and CAMTA1

miR-129 may also play a role in hematopoietic stem cell development. It has been shown that miR-129 may participate in a stem cell developmental network with EIF2C3 (eukaryotic translation initiation factor 2C, 3) and CAMTA1 (calmodulin binding transcription activator 1) with the induction of cell differentiation. It is postulated that miR-129 may affect differentiation and the cell cycle regulation [12] by inhibiting CAMTA1 translation. [13]

Clinical Relevance of miR-129

Biomarkers for Diagnostics

MicroRNAs have given cancer researchers a new perspective to understand and combat cancer. This is due to them being produced in a tissue-specific manner and their roles in many aspects of cellular process, such as proliferation and apoptosis. The vast amount of experimental data has enabled the specific microRNA signatures and profiles to be recognised and thus used as potential biomarkers in cancer diagnosis, therapy prediction and prognosis.

miR-129 has been identified as a potential candidate for development into a diagnostic biomarker. This is because of its integral role it plays in the proliferation of cells and its many recognisable, statistically significant and independent interactions with its targets as observed by the expression profiles in the study carried out by Ogawa et al.. [11]

Related Research Articles

Malignant transformation is the process by which cells acquire the properties of cancer. This may occur as a primary process in normal tissue, or secondarily as malignant degeneration of a previously existing benign tumor.

<span class="mw-page-title-main">MSH6</span> Protein-coding gene in the species Homo sapiens

MSH6 or mutS homolog 6 is a gene that codes for DNA mismatch repair protein Msh6 in the budding yeast Saccharomyces cerevisiae. It is the homologue of the human "G/T binding protein," (GTBP) also called p160 or hMSH6. The MSH6 protein is a member of the Mutator S (MutS) family of proteins that are involved in DNA damage repair.

mir-17 microRNA precursor family

The miR-17 microRNA precursor family are a group of related small non-coding RNA genes called microRNAs that regulate gene expression. The microRNA precursor miR-17 family, includes miR-20a/b, miR-93, and miR-106a/b. With the exception of miR-93, these microRNAs are produced from several microRNA gene clusters, which apparently arose from a series of ancient evolutionary genetic duplication events, and also include members of the miR-19, and miR-25 families. These clusters are transcribed as long non-coding RNA transcripts that are processed to form ~70 nucleotide microRNA precursors, that are subsequently processed by the Dicer enzyme to give a ~22 nucleotide products. The mature microRNA products are thought to regulate expression levels of other genes through complementarity to the 3' UTR of specific target messenger RNA.

mir-19 microRNA precursor family

There are 89 known sequences today in the microRNA 19 (miR-19) family but it will change quickly. They are found in a large number of vertebrate species. The miR-19 microRNA precursor is a small non-coding RNA molecule that regulates gene expression. Within the human and mouse genome there are three copies of this microRNA that are processed from multiple predicted precursor hairpins:

mir-1 microRNA precursor family

The miR-1 microRNA precursor is a small micro RNA that regulates its target protein's expression in the cell. microRNAs are transcribed as ~70 nucleotide precursors and subsequently processed by the Dicer enzyme to give products at ~22 nucleotides. In this case the mature sequence comes from the 3' arm of the precursor. The mature products are thought to have regulatory roles through complementarity to mRNA. In humans there are two distinct microRNAs that share an identical mature sequence, and these are called miR-1-1 and miR-1-2.

mIRN21 Non-coding RNA in the species Homo sapiens

microRNA 21 also known as hsa-mir-21 or miRNA21 is a mammalian microRNA that is encoded by the MIR21 gene.

An oncomir is a microRNA (miRNA) that is associated with cancer. MicroRNAs are short RNA molecules about 22 nucleotides in length. Essentially, miRNAs specifically target certain messenger RNAs (mRNAs) to prevent them from coding for a specific protein. The dysregulation of certain microRNAs (oncomirs) has been associated with specific cancer forming (oncogenic) events. Many different oncomirs have been identified in numerous types of human cancers.

mir-126

In molecular biology mir-126 is a short non-coding RNA molecule. MicroRNAs function to regulate the expression levels of other genes by several pre- and post-transcription mechanisms.

mir-127

mir-127 microRNA is a short non-coding RNA molecule with interesting overlapping gene structure. miR-127 functions to regulate the expression levels of genes involved in lung development, placental formation and apoptosis. Aberrant expression of miR-127 has been linked to different cancers.

miR-137

In molecular biology, miR-137 is a short non-coding RNA molecule that functions to regulate the expression levels of other genes by various mechanisms. miR-137 is located on human chromosome 1p22 and has been implicated to act as a tumor suppressor in several cancer types including colorectal cancer, squamous cell carcinoma and melanoma via cell cycle control.

mir-184 Non-coding microRNA molecule

In molecular biology, miR-184 microRNA is a short non-coding RNA molecule. MicroRNAs (miRNAs) function as posttranscriptional regulators of expression levels of other genes by several mechanisms. Several targets for miR-184 have been described, including that of mediators of neurological development, apoptosis and it has been suggested that miR-184 plays an essential role in development.

mir-200

In molecular biology, the miR-200 microRNA is a short RNA molecule. MicroRNAs function to regulate the expression levels of other genes by binding and cleaving mRNAs or inhibiting translation. The miR-200 family contains miR-200a, miR-200b, miR-200c, miR-141, and miR-429. There is growing evidence to suggest that miR-200 microRNAs are involved in cancer metastasis.

miR-203

In molecular biology miR-203 is a short non-coding RNA molecule. MicroRNAs function to regulate the expression levels of other genes by several mechanisms, such as translational repression and Argonaute-catalyzed messenger RNA cleavage. miR-203 has been identified as a skin-specific microRNA, and it forms an expression gradient that defines the boundary between proliferative epidermal basal progenitors and terminally differentiating suprabasal cells. It has also been found upregulated in psoriasis and differentially expressed in some types of cancer.

mir-205 Micro RNA involved in the regulation of multiple genes

In molecular biology miR-205 microRNA is a short RNA molecule. MicroRNAs function to regulate the expression levels of other genes by several mechanisms. They are involved in numerous cellular processes, including development, proliferation, and apoptosis. Currently, it is believed that miRNAs elicit their effect by silencing the expression of target genes.

mir-31

miR-31 has been characterised as a tumour suppressor miRNA, with its levels varying in breast cancer cells according to the metastatic state of the tumour. From its typical abundance in healthy tissue is a moderate decrease in non-metastatic breast cancer cell lines, and levels are almost completely absent in mouse and human metastatic breast cancer cell lines. Mir-31-5p has also been observed upregulated in Zinc Deficient rats compared to normal in ESCC and in other types of cancers when using this animal model. There has also been observed a strong encapsulation of tumour cells expressing miR-31, as well as a reduced cell survival rate. miR-31's antimetastatic effects therefore make it a potential therapeutic target for breast cancer. However, these two papers were formally retracted by the authors in 2015.

<span class="mw-page-title-main">HOXA11-AS1</span> Long non-coding RNA from the antisense strand in the homeobox A (HOXA gene).

HOXA11-AS lncRNA is a long non-coding RNA from the antisense strand in the homeobox A. The HOX gene contains four clusters. The sense strand of the HOXA gene codes for proteins. Alternative names for HOXA11-AS lncRNA are: HOXA-AS5, HOXA11S, HOXA11-AS1, HOXA11AS, or NCRNA00076. This gene is 3,885 nucleotides long and resides at chromosome 7 (7p15.2) and is transcribed from an independent gene promoter. Being a lncRNA, it is longer than 200 nucleotides in length, in contrast to regular non-coding RNAs.

<span class="mw-page-title-main">Cancer epigenetics</span> Field of study in cancer research

Cancer epigenetics is the study of epigenetic modifications to the DNA of cancer cells that do not involve a change in the nucleotide sequence, but instead involve a change in the way the genetic code is expressed. Epigenetic mechanisms are necessary to maintain normal sequences of tissue specific gene expression and are crucial for normal development. They may be just as important, if not even more important, than genetic mutations in a cell's transformation to cancer. The disturbance of epigenetic processes in cancers, can lead to a loss of expression of genes that occurs about 10 times more frequently by transcription silencing than by mutations. As Vogelstein et al. points out, in a colorectal cancer there are usually about 3 to 6 driver mutations and 33 to 66 hitchhiker or passenger mutations. However, in colon tumors compared to adjacent normal-appearing colonic mucosa, there are about 600 to 800 heavily methylated CpG islands in the promoters of genes in the tumors while these CpG islands are not methylated in the adjacent mucosa. Manipulation of epigenetic alterations holds great promise for cancer prevention, detection, and therapy. In different types of cancer, a variety of epigenetic mechanisms can be perturbed, such as the silencing of tumor suppressor genes and activation of oncogenes by altered CpG island methylation patterns, histone modifications, and dysregulation of DNA binding proteins. There are several medications which have epigenetic impact, that are now used in a number of these diseases.

In molecular biology mir-186 microRNA is a short RNA molecule. MicroRNAs function to regulate the expression levels of other genes by several mechanisms.

DNA methylation in cancer plays a variety of roles, helping to change the healthy cells by regulation of gene expression to a cancer cells or a diseased cells disease pattern. One of the most widely studied DNA methylation dysregulation is the promoter hypermethylation where the CPGs islands in the promoter regions are methylated contributing or causing genes to be silenced.

References

  1. 1 2 Lagos-Quintana, M; Rauhut R; Yalcin A; Meyer J; Lendeckel W; Tuschl T (2002). "Identification of tissue-specific microRNAs from mouse". Curr Biol. 12 (9): 735–739. doi:10.1016/S0960-9822(02)00809-6. hdl: 11858/00-001M-0000-0010-94EF-7 . PMID   12007417. S2CID   7901788.
  2. ↑ Lagos-Quintana M, Rauhut R, Meyer J, Borkhardt A, Tuschl T (2003). "New microRNAs from mouse and human". RNA. 9 (2): 175–9. doi:10.1261/rna.2146903. PMC   1370382 . PMID   12554859.
  3. ↑ He X, Zhang Q, Liu Y, Pan X (2007). "Cloning and identification of novel microRNAs from rat hippocampus". Acta Biochim Biophys Sin (Shanghai). 39 (9): 708–14. doi: 10.1111/j.1745-7270.2007.00324.x . PMID   17805466.
  4. ↑ Chen PY, Manninga H, Slanchev K, Chien M, Russo JJ, Ju J, et al. (2005). "The developmental miRNA profiles of zebrafish as determined by small RNA cloning". Genes Dev. 19 (11): 1288–93. doi:10.1101/gad.1310605. PMC   1142552 . PMID   15937218.
  5. ↑ Calin GA, Sevignani C, Dumitru CD, Hyslop T, Noch E, Yendamuri S, et al. (2004). "Human microRNA genes are frequently located at fragile sites and genomic regions involved in cancers". Proc Natl Acad Sci U S A. 101 (9): 2999–3004. Bibcode:2004PNAS..101.2999C. doi: 10.1073/pnas.0307323101 . PMC   365734 . PMID   14973191.
  6. ↑ Barad O, Meiri E, Avniel A, Aharonov R, Barzilai A, Bentwich I, et al. (2004). "MicroRNA expression detected by oligonucleotide microarrays: System establishment and expression profiling in human tissues". Genome Res. 14 (12): 2486–94. doi:10.1101/gr.2845604. PMC   534673 . PMID   15574827.
  7. ↑ Wu J, Qian J, Li C, Kwok L, Cheng F, Liu P, et al. (2010). "miR-129 regulates cell proliferation by downregulating Cdk6 expression". Cell Cycle. 9 (9): 1809–18. doi: 10.4161/cc.9.9.11535 . PMID   20404570.
  8. ↑ Shen R, Pan S, Qi S, Lin X, Cheng S (2010). "Epigenetic repression of microRNA-129-2 leads to overexpression of SOX4 in gastric cancer". Biochem Biophys Res Commun. 394 (4): 1047–52. doi:10.1016/j.bbrc.2010.03.121. PMID   20331975.
  9. ↑ Huang YW, Liu JC, Deatherage DE, Luo J, Mutch DG, Goodfellow PJ, et al. (2009). "Epigenetic Repression of microRNA-129-2 Leads to Overexpression of SOX4 Oncogene in Endometrial Cancer". Cancer Res. 69 (23): 9038–46. doi:10.1158/0008-5472.CAN-09-1499. PMC   2789184 . PMID   19887623.
  10. ↑ Dyrskjøt L, Ostenfeld MS, Bramsen JB, Silahtaroglu AN, Lamy P, Ramanathan R, et al. (2009). "Genomic profiling of microRNAs in bladder cancer: miR-129 is associated with poor outcome and promotes cell death in vitro". Cancer Res. 69 (11): 4851–60. doi: 10.1158/0008-5472.CAN-08-4043 . PMID   19487295.
  11. 1 2 Ogawa R, Ishiguro H, Kuwabara Y, Kimura M, Mitsui A, Katada T, et al. (2009). "Expression profiling of micro-RNAs in human esophageal squamous cell carcinoma using RT-PCR". Med Mol Morphol. 42 (2): 102–9. doi:10.1007/s00795-009-0443-1. PMID   19536617. S2CID   7362568.
  12. ↑ Nakatani K, Nishioka J, Itakura T, Nakanishi Y, Horinouchi J, Abe Y, et al. (2004). "Cell cycle-dependent transcriptional regulation of calmodulin-binding transcription activator 1 in neuroblastoma cells". Int J Oncol. 24 (6): 1407–12. doi:10.3892/ijo.24.6.1407 (inactive 31 January 2024). PMID   15138581.{{cite journal}}: CS1 maint: DOI inactive as of January 2024 (link)
  13. ↑ Liao R, Sun J, Zhang L, Lou G, Chen M, Zhou D, et al. (2008). "MicroRNAs play a role in the development of human hematopoietic stem cells". J Cell Biochem. 104 (3): 805–17. doi:10.1002/jcb.21668. PMID   18189265. S2CID   23455398.

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