# Mir-10 microRNA precursor family
The **mir-10 microRNA precursor family** is a group of evolutionarily ancient genes that encode short non-coding RNAs involved in post-transcriptional gene regulation. The family is highly conserved across animals and has drawn sustained research interest because its members are embedded in or near the [Hox gene](https://www.edgepedia.org/hox-gene) clusters, the conserved transcription-factor genes that pattern the anterior-posterior body axis of bilaterian animals, and because they regulate and are coexpressed with those Hox genes.[1](https://pmc.ncbi.nlm.nih.gov/articles/PMC3256350/)
| Key fact | Detail |
|---|---|
| What it encodes | Short non-coding RNAs (microRNAs) that repress target mRNAs; the family is highly conserved across the bilaterian clade[1](https://pmc.ncbi.nlm.nih.gov/articles/PMC3256350/) |
| Evolutionary origin | miR-100, the ancestral family member, is believed to be the most ancient animal miRNA, arising in a common ancestor of eumetazoa around 650 million years ago; miR-10 and miR-125 derive from duplications of miR-100 before the divergence of protostomes and deuterostomes[1](https://pmc.ncbi.nlm.nih.gov/articles/PMC3256350/) • [2](https://pmc.ncbi.nlm.nih.gov/articles/PMC3049427/) |
| Genomic position | Located in a conserved position within the Hox complex of animals, close to Hox group 4 paralogues[2](https://pmc.ncbi.nlm.nih.gov/articles/PMC3049427/) • [4](https://pmc.ncbi.nlm.nih.gov/articles/PMC3185001/) |
| Developmental role | Zebrafish miR-10 members repress the Hox transcripts HoxB1a and HoxB3a; Hox-cluster-embedded miRNAs preferentially target Hox mRNAs[5](https://pmc.ncbi.nlm.nih.gov/articles/PMC2148072/) • [8](https://www.nature.com/articles/nrg2400) |
| Cancer relevance | miR-10a and miR-10b act as both tumor suppressors and oncogenes in different cancers; miR-10b promotes metastasis in breast and other cancers[9](https://pmc.ncbi.nlm.nih.gov/articles/PMC11720153/) • [10](https://pmc.ncbi.nlm.nih.gov/articles/PMC12099151/) |
| Database scope | MirGeneDB 3.0 assigns 664 MIR-10 family genes across 110 species, with family origin at Eumetazoa[11](https://awi.cuhk.edu.cn/miRTarBase/records/MIRT053210/family/mirgenedb/?mirna_id=hsa-mir-125b-2&transcript=NM_001202513.2) |
## Evolutionary history
The miR-10/100 family is one of the oldest known microRNA lineages. miR-100 is believed to be the most ancient animal microRNA, thought to have arisen in a common ancestor of eumetazoa around 650 million years ago. At the root of the bilaterian lineage, duplications of miR-100 gave rise to miR-10 and miR-125, and a later duplication of miR-10 produced miR-993, found in protostomes. Separate whole-genome duplication events in the vertebrate clade further expanded the family, though some paralogues were subsequently lost.[1](https://pmc.ncbi.nlm.nih.gov/articles/PMC3256350/)
A study using covariance model approaches, alignment inspection, and synteny to exhaustively identify miR-100/10 family homologues in sequenced genomes dated the three duplication events that gave rise to the miR-100/10 subfamilies to before the expansion of the [Eumetazoa](https://www.edgepedia.org/eumetazoa). The most parsimonious reading of the conservation patterns is that miR-10 and miR-125 derive from independent duplications of the ancestral miR-100 before protostome-deuterostome diversification, while miR-993 arose soon after the protostome divergence.[2](https://pmc.ncbi.nlm.nih.gov/articles/PMC3049427/)
**Arm switching.** The family is also a textbook case of arm switching, the phenomenon in which the dominant mature microRNA produced from a hairpin precursor changes over evolutionary time. In *Drosophila melanogaster*, both the 3′ arm miR-10 and the less abundant 5′ arm miR-10 are expressed from the single miR-10 gene in the Antennapedia Hox cluster, and both are predicted to target Hox genes.[1](https://pmc.ncbi.nlm.nih.gov/articles/PMC3256350/) Northern blots in the fly showed that while both arms increase in expression throughout embryogenesis, miR-10-3p is more abundant than miR-10-5p.[12](https://flybase.org/reports/FBgn0262424)
## Location within the Hox clusters
Hox genes are highly conserved transcription factors crucial for correct anterior-posterior patterning of bilaterian animals, and the Hox complex originated before the divergence of protostomes and deuterostomes. Because miR-10 family members sit in close proximity to Hox group 4 paralogues, the family was initially suggested to play a role in determining body plans.[1](https://pmc.ncbi.nlm.nih.gov/articles/PMC3256350/) • [2](https://pmc.ncbi.nlm.nih.gov/articles/PMC3049427/)
The relationship is strikingly well conserved. The zebrafish genome contains three miR-10 genes, miR-10b-1, miR-10b-2, and miR-10c, each of which lies upstream of its corresponding Hox group 4 paralogue: hoxd4a, hoxc4a, and hoxb4a, respectively. Beginning past the zebrafish hoxb5a gene, a lengthy primary transcript covers miR-10c, hoxb4a, and hoxb3a, and its expression occurs in a region lying behind hoxb4a.[4](https://pmc.ncbi.nlm.nih.gov/articles/PMC3185001/) A fifth copy, miR-10d, is located in a region corresponding to the degenerated zebrafish HoxDb cluster, which has lost all Hox-related sequences except the miR-10d gene itself.[1](https://pmc.ncbi.nlm.nih.gov/articles/PMC3256350/)
Not all animals retain this arrangement. The majority of the ancient Hox cluster has been lost in nematodes, and the miR-10 orthologue miR-57 is now encoded outside the remaining Hox genes.[1](https://pmc.ncbi.nlm.nih.gov/articles/PMC3256350/)
## Developmental function
Several lines of evidence connect Hox-gene regulation with the regulation of miR-10 family members. In zebrafish, miR-10 family members repress the two Hox transcripts HoxB1a and HoxB3a. In the case of a long-range HoxB3a transcript that includes miR-10c within its primary transcript, the microRNA acts in an essentially autoregulatory fashion.[5](https://pmc.ncbi.nlm.nih.gov/articles/PMC2148072/) An analysis of predicted microRNA targets found that Hox cluster-embedded miRNAs, which include miR-10 (found throughout [Bilateria](https://www.edgepedia.org/bilateria)), miR-196 (vertebrates), and miR-iab4 (insects), preferentially target Hox mRNAs.[8](https://www.nature.com/articles/nrg2400)
The family's expression is tied to retinoic acid signaling, a morphogen involved in neuronal differentiation. In pluripotent stem cell-derived midbrain progenitors, constitutive induction of HOX cluster genes and miR-10 family members was confirmed along retinoic acid-induced neuronal differentiation, and ectopic miR-10 expression recapitulated a hypothesized caudalization effect, shifting progenitors toward a more posterior identity.[6](https://research.cuhk.edu.hk/en/publications/dynamic-epigenetic-regulation-of-mir-10-family-governs-the-caudal-3/) During in vitro megakaryocytic differentiation, levels of both miR-10a and miR-10b were markedly decreased, implying specific roles in retinoic acid-induced differentiation of various tissues.[7](https://www.tandfonline.com/doi/pdf/10.4161/rna.8.5.16324)
## Roles in cancer
**Dual roles.** miR-10a-5p and miR-10b-5p act as both tumor suppressors and oncogenes in diverse cancers, with different target genes in different tissue contexts.[9](https://pmc.ncbi.nlm.nih.gov/articles/PMC11720153/) In the majority of cancers investigated for miR-10 family expression, there is a tendency toward increased levels, suggesting oncogenic potential in most cell types; head and neck squamous cell carcinoma is one of the few cancers with decreased miR-10a expression.[7](https://www.tandfonline.com/doi/pdf/10.4161/rna.8.5.16324)
**miR-10b and metastasis.** miR-10b plays a pro-tumorigenic, pro-metastatic role in several malignancies, including endometrial cancer, osteosarcoma, esophageal cancer, laryngeal cancer, retinoic acid-induced neuroblastoma, and thyroid cancer. In clear cell renal carcinoma, a four-miRNA tumor-tissue signature including miR-10b was associated with metastasis (odds ratio 5.5, 95% CI 1.23–24.51) and with survival (relative risk 12.68, 95% CI 2.97–54.13, P < 0.0001) for high-risk versus low-risk classifications.[13](https://pmc.ncbi.nlm.nih.gov/articles/PMC6176190/) These features have made miR-10b a candidate clinical marker and therapeutic target for metastatic disease, which comprises up to 90% of cancer-related deaths.[10](https://pmc.ncbi.nlm.nih.gov/articles/PMC12099151/)
**Hematologic cancers.** miR-10a expression was decreased in a panel of hematological cancer cell lines, in acute myeloid leukemia, and in chronic myeloid leukemia relative to CD34⁺ cells, while miR-10b was overexpressed in B-cell chronic lymphocytic leukemia compared to normal CD5⁺ cells. Among some acute myeloid leukemia cases carrying nucleophosmin (NPM1) gene mutations, the three miRNAs showing the greatest overexpression were found to be miR-10a, miR-10b, and miR-100.[7](https://www.tandfonline.com/doi/pdf/10.4161/rna.8.5.16324)
Although miR-10b is thought to play a key role in development, mice lacking the miR-10b gene survive, showing no meaningful differences in body weight, lifespan, fertility, or complete blood count.[10](https://pmc.ncbi.nlm.nih.gov/articles/PMC12099151/)
## Nomenclature and databases
MicroRNA naming distinguishes the precursor from the mature product: mature sequences are designated "miR" while precursor hairpins are labeled "mir". Paralogous sequences whose mature miRNAs differ at only one or two positions receive lettered suffixes, as in mouse mmu-miR-10a and mmu-miR-10b.[3](https://pmc.ncbi.nlm.nih.gov/articles/PMC1347474/)
Database curation matters for this family. MirGeneDB, a manually curated microRNA gene database, categorizes microRNAs by shared evolutionary history rather than shared seed sequences, which leads it to include miRBase's mir-100 and mir-125 entries within its MIR-10 family. In MirGeneDB 3.0 the MIR-10 family has an origin at Eumetazoa and comprises 664 genes across 110 species.[11](https://awi.cuhk.edu.cn/miRTarBase/records/MIRT053210/family/mirgenedb/?mirna_id=hsa-mir-125b-2&transcript=NM_001202513.2) • [14](https://pmc.ncbi.nlm.nih.gov/articles/PMC11701709/) In *Drosophila melanogaster*, the single mir-10 gene (FlyBase ID FBgn0262424) sits at cytological position 84A5 on chromosome 3R within the Antennapedia cluster, and its annotation represents the precursor stem loop rather than a single mature miRNA.[12](https://flybase.org/reports/FBgn0262424)
## References
1. [The miR-10 microRNA precursor family (Ørom et al., RNA Biology 2011)](https://pmc.ncbi.nlm.nih.gov/articles/PMC3256350/)
2. [MicroRNA evolution by arm switching (Tanzer et al., EMBO Reports 2010)](https://pmc.ncbi.nlm.nih.gov/articles/PMC3049427/)
3. [miRBase: microRNA sequences, targets and gene nomenclature (Griffiths-Jones et al., Nucleic Acids Research 2006)](https://pmc.ncbi.nlm.nih.gov/articles/PMC1347474/)
4. [Nuclear Accumulation of an Uncapped RNA Produced by Drosha Cleavage of a Transcript Encoding miR-10b and HOXD4](https://pmc.ncbi.nlm.nih.gov/articles/PMC3185001/)
5. [MiR-10 Represses HoxB1a and HoxB3a in Zebrafish (Woltering & Durston, PLoS ONE 2008)](https://pmc.ncbi.nlm.nih.gov/articles/PMC2148072/)
6. [Dynamic epigenetic regulation of miR-10 family governs the caudalization of floor plate neural progenitors, The Chinese University of Hong Kong](https://research.cuhk.edu.hk/en/publications/dynamic-epigenetic-regulation-of-mir-10-family-governs-the-caudal-3/)
7. [The miR-10 microRNA precursor family (Ørom et al., RNA Biology 2011, Taylor & Francis full text)](https://www.tandfonline.com/doi/pdf/10.4161/rna.8.5.16324)
8. [MicroRNAs in the Hox network: an apparent link to posterior prevalence (Nicolas et al., Nature Reviews Genetics 2008)](https://www.nature.com/articles/nrg2400)
9. [Dual Roles of miR-10a-5p and miR-10b-5p as Tumor Suppressors and Oncogenes in Diverse Cancers](https://pmc.ncbi.nlm.nih.gov/articles/PMC11720153/)
10. [miR-10b as a Clinical Marker and a Therapeutic Target for Metastatic Breast Cancer](https://pmc.ncbi.nlm.nih.gov/articles/PMC12099151/)
11. [MIR-10 Family, MirGeneDB 3.0 family annotation via miRTarBase](https://awi.cuhk.edu.cn/miRTarBase/records/MIRT053210/family/mirgenedb/?mirna_id=hsa-mir-125b-2&transcript=NM_001202513.2)
12. [FlyBase Gene Report: Dmel\mir-10](https://flybase.org/reports/FBgn0262424)
13. [The fundamental role of miR-10b in metastatic cancer](https://pmc.ncbi.nlm.nih.gov/articles/PMC6176190/)
14. [MirGeneDB 3.0: improved taxonomic sampling, uniform nomenclature of novel conserved microRNA families and updated covariance models (Nucleic Acids Research 2025)](https://pmc.ncbi.nlm.nih.gov/articles/PMC11701709/)
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*Topic: Encyclopedia › Life and health › Biological foundations › RNA and gene regulation › Small regulatory RNAs › microRNA precursor and gene families (gene records) › Hox-cluster and developmental miRNA families*
*Initially written Sep 17, 2026 · Reviewed: Oct 21, 2026 · Edited: Oct 15, 2026; Oct 21, 2026 · Last review: Oct 21, 2026*
*Copyright 2026 EdgeChat AI, a subsidiary of Biostate AI.*
License: Edgepedia Community License 1.0, https://www.edgepedia.org/edgepedia/license