LUM (Lumican) Gene
A Small Leucine-Rich Proteoglycan Involved in Extracellular Matrix Organization and Corneal Transparency
Gene Information Card
| Symbol | LUM |
|---|---|
| Full Name | Lumican |
| Gene Type | Protein coding |
| Chromosomal Location | 12q21.33 |
| NCBI Gene ID | 4060 ncbi.nlm.nih.gov/gene/4060 |
| Ensembl ID | ENSG00000139329 |
| UniProt ID | P51884 |
| OMIM ID | 600616 |
| HGNC ID | 6724 |
| Aliases | LDC, SLRR2D, KSPG, LUMICAN |
Description
The LUM gene encodes lumican, a member of the small leucine-rich proteoglycan (SLRP) family. Lumican is a major component of the extracellular matrix, particularly in the cornea, where it regulates collagen fibril assembly and maintains transparency. It also modulates cell migration, proliferation, and inflammation. Mutations in LUM are associated with corneal dystrophies, and altered expression is observed in various cancers and fibrotic diseases.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Corneal dystrophy, congenital stromal | Missense mutations (e.g., p.Asp299Asn) disrupt lumican structure, impairing collagen fibrillogenesis and leading to corneal opacification. | OMIM #610048; ClinVar |
| High myopia | Polymorphisms in LUM are associated with increased risk of high myopia, possibly through altered scleral extracellular matrix remodeling. | NCBI Gene; PubMed |
| Cancer (breast, colorectal, pancreatic) | Lumican overexpression in stroma promotes tumor progression via integrin signaling and ECM remodeling; also acts as a tumor suppressor in some contexts. | COSMIC; PubMed |
| Fibrosis (liver, kidney, lung) | Upregulation of lumican in fibrotic tissues correlates with collagen deposition and disease severity. | UniProt; PubMed |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Cornea | High | High |
| Skin | Moderate | Medium |
| Artery | Moderate | Medium |
| Lung | Low | Low |
| Liver | Low | Low |
| Kidney | Low | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| Corneal fibroblasts | High | Primary cells |
| HepG2 | Low | Hepatocellular carcinoma |
| MCF7 | Low | Breast cancer |
| A549 | Low | Lung cancer |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.895G>A (p.Asp299Asn) | Missense | Rare | Dominant negative; causes congenital stromal corneal dystrophy |
| c.1073C>T (p.Thr358Met) | Missense | Rare | Uncertain significance; reported in corneal dystrophy |
| c.501C>A (p.Asn167Lys) | Missense | Rare | Likely benign; population frequency low |
Mutation functional classification
Loss of Function (LOF)
Not well established; no clear loss-of-function mutations reported.
Gain of Function (GOF)
Not documented.
Dominant Negative (DN)
p.Asp299Asn acts as dominant negative, disrupting collagen fibril assembly in cornea.
View complete mutation data：
Gene Ontology (GO)
| • proteinaceous extracellular matrix (GO:0005578) | • extracellular matrix structural constituent (GO:0030020) |
| • collagen binding (GO:0005518) | • extracellular matrix organization (GO:0030198) |
| • cell adhesion (GO:0007155) | • extracellular structure organization (GO:0043062) |
Pathways
• ECM-receptor interaction (KEGG: hsa04512)
• Proteoglycans in cancer (KEGG: hsa05205)
• Focal adhesion (KEGG: hsa04510)
Protein Summary
Lumican is a 338-amino acid proteoglycan with a core protein containing leucine-rich repeats and keratan sulfate chains. It is secreted into the extracellular matrix, where it binds collagen fibrils and regulates their diameter and spacing. Lumican also interacts with integrins, growth factors, and matrix metalloproteinases, influencing cell behavior. Its expression is highest in the cornea, but it is also found in skin, blood vessels, and connective tissues.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| LUM Knockout HEK293 Cell Line | EDJ-KQ2675 | Human | 4060 | Details Get a Quote |
| LUM Knockout A-549 Cell Line | EDJ-KQ23466 | Human | 4060 | Details Get a Quote |
| LUM Knockout HeLa Cell Line | EDJ-KQ23467 | Human | 4060 | Details Get a Quote |
| LUM Knockout HCT 116 Cell Line | EDJ-KQ70775 | Human | 4060 | Details Get a Quote |
