circRNA basic information
circBase ID: hsa_circ_0124008
Name: hsa_circ_PFKFB4
Synonym: circPFKFB4
Host Gene: PFKFB4
Genomic location(hg19): -
Genomic location(hg38): -
Subcellular localization: nucleus and cytoplasm
 
 
 
 
 
 
 
Disease basic information
MONDO ID:
0007254
MONDO name: breast cancer
Disease details: breast cancer / BC
Disease DO ID:
1612
Disease MeSH ID:
-
Disease NCIt ID:
C9335
Disease ICD11 ID:
1047754165
Disease OMIM ID:
-
Species: Human
Species details: Homo sapiens
Tissue specimen:

BC tissues; paracancerous tissues; adjacent normal tissues; normal breast tissues; xenograft tumors

Cell lines:

MCF-7; MDA-MB-231; BT-474; MDA-MB-453; MCF-10A; HEK293T

In vivo animal model:

cell line-derived xenograft

circRNA-disease information
Expression pattern:
UP
Associated gene: HIF1alpha, DDB1, DDB2, CRL4DDB2 E3 ubiquitin ligase, p27
Associated microRNA: -
Biological function: promotes proliferation; promotes tumorigenesis; increases cell cycle progression; inhibits apoptosis
Molecular mechanism: HIF1alpha binds to the PFKFB4 promoter to induce circPFKFB4 biogenesis under hypoxia; circPFKFB4 directly binds DDB1 and DDB2 to facilitate CRL4DDB2 E3 ligase assembly, stabilizes DDB2, and promotes p27 ubiquitination and degradation
Biological pathway or process:

ubiquitination (promotes); cell cycle (promotes); proliferation (promotes); apoptosis (inhibits); other pathway/process (promotes)

Detected method:
Q
M
Validation methods:

Microarray; RT-qPCR; Back-Splice Junction PCR / divergent primers PCR; RNase R Treatment; Actinomycin D / DRB Stability Assay; Sanger Sequencing; Nuclear-Cytoplasmic Fractionation; FISH / smFISH; ISH (In Situ Hybridization); Clinical Sample Validation; RIP (RNA Immunoprecipitation); RNA Pull-Down; Co-IP; Luciferase Reporter Assay; ChIP / ChIP-seq; Transfection; CCK8; EdU Staining; Colony Formation Assay; Annexin V/PI Flow Cytometry; Cell Cycle Assay; TUNEL; Western Blot; In Vivo Animal Model; IHC (Immunohistochemistry); Survival Analysis; ROC Analysis; Bioinformatics Analysis

Clinical significance:

Highly expressed in BC tissues/cell lines; positively correlated with advanced clinical stage; higher expression associated with poor prognosis; potential diagnostic value (ROC AUC 0.677); independent predictor of poor prognosis

Description:

circPFKFB4 (hsa_circ_0124008) is induced by hypoxia in BC and is up-regulated in tumors, where high expression predicts poor prognosis. It promotes BC cell proliferation and tumor growth by binding DDB1/DDB2 to enhance CRL4DDB2 assembly and drive p27 ubiquitination and degradation, facilitating cell-cycle progression under hypoxia.

Confidence score:

0.904

Other information
Title:

Hypoxia-inducible CircPFKFB4 Promotes Breast Cancer Progression by Facilitating the CRL4DDB2 E3 Ubiquitin Ligase-mediated p27 Degradation.

Journal: International journal of biological sciences
Published: 2022
PubMed ID: 35813480
Study type:

combined biological and clinical study

Data availability: -
Code availability: -