circRNA basic information
circBase ID: hsa_circ_0001819
Name: hsa_circ_UBR5
Synonym: circUBR5
Host Gene: UBR5
Genomic location(hg19): chr8:103372298-103373854:-
Genomic location(hg38): chr8:102360070-102361626:-
Subcellular localization: cytoplasm; exosome
 
 
 
 
 
 
 
Disease basic information
MONDO ID:
 0006409
MONDO name: signet ring cell gastric adenocarcinoma
Disease details: gastric signet-ring cell carcinoma
Disease DO ID:
 8025
Disease MeSH ID:
 -
Disease NCIt ID:
 C5250
Disease ICD11 ID:
 -
Disease OMIM ID:
 -
Species: Human
Species details: Homo sapiens
Tissue specimen:

gastric cancer tissues; GSRCC tissues; GAC tissues; matched adjacent nontumor tissues; tumor tissues; plasma; plasma-derived exosomes; tissue microarrays
Cell lines:

MKN-45; KATO-III; AGS; NUGC-3; HEK293T
In vivo animal model:

cell line-derived xenograft
circRNA-disease information
Expression pattern:
UP
Associated gene: CYP19A1, ACAT1, PSMD14, Ago2, ESR1, GREB1
Associated microRNA: hsa-miR-1208
Biological function: Promotes proliferation, migration, invasion, metastasis, tumor growth, lipid droplet accumulation, cisplatin resistance, chemoresistance transfer, cholesterol metabolic reprogramming, and estrogen signaling in gastric cancer/GSRCC.
Molecular mechanism: Cytoplasmic circUBR5 acts as a ceRNA sponge for hsa-miR-1208 to derepress CYP19A1 and activate estrogen signaling; it also acts as a protein scaffold that binds ACAT1 and recruits PSMD14 to reduce ACAT1 ubiquitination and stabilize ACAT1, thereby promoting cholesterol esterification and lipid droplet accumulation; exosomal circUBR5 transfers cisplatin resistance.
Biological pathway or process:

proliferation (promotes); migration (promotes); invasion (promotes); metastasis (promotes); chemoresistance (promotes); drug resistance (promotes); lipid metabolism (promotes); ceRNA regulation (promotes); ubiquitination (inhibits); other pathway/process (promotes)
Detected method:
Q
H
S
Validation methods:

Back-Splice Junction PCR / divergent primers PCR; RNase R Treatment; Sanger Sequencing; Actinomycin D / DRB Stability Assay; RT-qPCR; RNA-seq; FISH / smFISH; IF (Immunofluorescence); Nuclear-Cytoplasmic Fractionation; Clinical Sample Validation; RIP (RNA Immunoprecipitation); RNA Pull-Down; Co-IP; Luciferase Reporter Assay; Transfection; CCK8; Colony Formation Assay; Transwell Assay; In Vivo Animal Model; H&E Staining; IHC (Immunohistochemistry); Western Blot; ELISA; Cohort Study; Survival Analysis; ROC Analysis; Bioinformatics Analysis
Clinical significance:

CircUBR5 is associated with advanced TNM stage, lymph node metastasis, metastasis, poor overall survival, diagnostic biomarker potential in plasma exosomes, prognostic biomarker potential, and therapeutic target potential for cisplatin-resistant GSRCC.
Description:

CircUBR5/hsa_circ_0001819 is an upregulated human circRNA in GSRCC and broader GC contexts that promotes tumor proliferation, metastasis, and cisplatin resistance. It acts through dual mechanisms: a hsa-miR-1208/CYP19A1 ceRNA axis that activates estrogen signaling and a protein-scaffold mechanism recruiting PSMD14 to stabilize ACAT1 and reprogram cholesterol metabolism. CircUBR5 is also packaged into exosomes, enabling transfer of chemoresistance, and high expression predicts advanced disease and poor survival.
Confidence score:

0.9036
Other information
Title:

Exosomal circUBR5 drives metastasis and chemoresistance in gastric signet-ring cell carcinoma by reprogramming cholesterol metabolism through the hsa-miR-1208/CYP19A1 axis and ACAT1 upregulation.

Journal: Cancer letters
Published: 2026
PubMed ID: 41580013
Study type:

combined biological and clinical study
Data availability: Data available from the corresponding author upon reasonable request; Supplementary data: https://doi.org/10.1016/j.canlet.2026.218279; TCGA stomach adenocarcinoma dataset
Code availability: -