CBX7: Chromobox Protein 7 – A Key Regulator in Cancer and Stem Cell Biology
Comprehensive genomic and functional overview of CBX7, a Polycomb group protein involved in transcriptional repression, cellular senescence, and tumor suppression.
Gene Information Card
| Symbol | CBX7 |
|---|---|
| Full Name | Chromobox 7 |
| Gene Type | Protein coding |
| Chromosomal Location | 22q13.1 |
| NCBI Gene ID | 23492 ncbi.nlm.nih.gov/gene/23492 |
| Ensembl ID | ENSG00000100330 |
| UniProt ID | O95931 |
| OMIM ID | 606452 |
| HGNC ID | 1557 |
| Aliases | PC2, MGC1387 |
Description
CBX7 (Chromobox 7) encodes a component of the Polycomb repressive complex 1 (PRC1). It binds histone H3 trimethylated at lysine 27 (H3K27me3) via its chromodomain and contributes to transcriptional repression of target genes involved in development, differentiation, and senescence. CBX7 is frequently downregulated in various cancers and acts as a tumor suppressor by promoting cellular senescence and inhibiting epithelial-mesenchymal transition.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Prostate cancer | Loss of CBX7 expression leads to derepression of oncogenic pathways and increased proliferation. | PMID: 19029980 |
| Lung cancer | Reduced CBX7 levels correlate with poor prognosis and enhanced metastatic potential. | PMID: 23382210 |
| Breast cancer | CBX7 silencing promotes invasion and stemness via PRC1-mediated chromatin changes. | PMID: 25609812 |
| Gastric cancer | CBX7 downregulation is associated with advanced tumor stage and lymph node metastasis. | PMID: 27058793 |
| Colorectal cancer | CBX7 loss contributes to Wnt/β-catenin pathway activation and tumor progression. | PMID: 27562873 |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Testis | 12.5 | Medium |
| Thyroid | 10.2 | Medium |
| Prostate | 8.9 | Medium |
| Lung | 6.3 | Low |
| Breast | 5.1 | Low |
| Colon | 4.8 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| MCF7 (breast cancer) | 7.2 | Moderate expression |
| A549 (lung cancer) | 5.8 | Low expression |
| PC3 (prostate cancer) | 4.1 | Low expression |
| HEK293 (embryonic kidney) | 9.5 | High expression |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.1A>G (p.Met1?) | Missense | <0.1% | Likely loss of start codon; predicted loss of function |
| c.325C>T (p.Arg109Trp) | Missense | 0.2% | Located in chromodomain; may impair H3K27me3 binding |
| c.487G>A (p.Gly163Arg) | Missense | 0.1% | Unknown significance; rare in population databases |
Mutation functional classification
Loss of Function (LOF)
Frameshift or nonsense mutations leading to truncated protein or nonsense-mediated decay; also missense mutations in the chromodomain that disrupt histone binding.
Gain of Function (GOF)
Not well documented; no recurrent activating mutations reported in COSMIC or ClinVar.
Dominant Negative (DN)
Hypothesized for certain missense variants that retain dimerization but lose chromatin binding, though not experimentally validated.
View complete mutation data：
Gene Ontology (GO)
Pathways
• Polycomb repressive complex (PRC1) – hsa:04110
• Transcriptional misregulation in cancer – hsa:05202
• Cellular senescence – hsa:04218
Protein Summary
CBX7 is a 251-amino acid protein containing an N-terminal chromodomain that recognizes H3K27me3 and a C-terminal Polycomb box (PC box) mediating interaction with other PRC1 components. It is predominantly nuclear and functions in transcriptional repression of genes such as INK4a/ARF, thereby regulating senescence and stem cell self-renewal. CBX7 is also implicated in RNA splicing and DNA damage response.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| CBX7 Knockout HEK293 Cell Line | EDJ-KQ2997 | Human | 23492 | Details Get a Quote |
| CBX7 Knockout A-549 Cell Line | EDJ-KQ24190 | Human | 23492 | Details Get a Quote |
| CBX7 Knockout HCT 116 Cell Line | EDJ-KQ24191 | Human | 23492 | Details Get a Quote |
| CBX7 Knockout HeLa Cell Line | EDJ-KQ24192 | Human | 23492 | Details Get a Quote |
