Dataset Information

Epithelial deletion of CUL4B increased myeloid-derived suppressor cells-mediated immunosuppression to promote ApcMin/+ tumor formation

ABSTRACT: Cullin 4B (CUL4B) is a scaffold protein of E3 ubiquitin ligase complex and has been found frequently overexpressed in various types of cancer. By repressing tumor suppressors, CUL4B is indicated as pro-oncogenic gene in oncogenesis. Reversely, recent studies reveal that deletion of CUL4B in hematopoietic system exerts tumor suppressive effect in tumor bearing hosts. However, the role of CUL4B in tumor initiation remains unknown. Here we report that CUL4B deficiency in the intestinal epithelium accelerates ApcMin/+ tumor formation. CUL4B in cancer cells restricts the accumulation of tumor-infiltrating CD11b+Gr-1+ MDSCs to prohibit the adenoma permissive microenvironment and thus increases the number of antitumor CD8+ T cells. Addition of MDSCs to ex vivo cultured ApcMin/+; Cul4bΔIEC tumor organoids rescues their phenotypic alteration in stemness, suggesting a reciprocally strengthened immunosuppressive effect between CUL4B deficient tumor cells and MDSCs. Mechanistically, inhibiting CUL4B epigenetically activates the expression of secreted chemokines and proteins including G-CSF to enroll MDSCs. Our findings suggest that epithelial deletion of CUL4B creates a tumor-prone microenvironment during ApcMin/+ tumor formation and provide a potential strategy to overcome colon cancer initiation and progress in the Wnt-disturbed context.

ORGANISM(S): Mus musculus

PROVIDER: GSE189382 | GEO | 2024/11/20

REPOSITORIES: GEO

ACCESS DATA

Dataset's files

Source:

			Action	DRS
		Other

Items per page:

1 - 1 of 1

Similar Datasets

Project description:Cullin 4B (CUL4B), a scaffold protein that assembles CRL4B ubiquitin ligase complexes, has been reported to be overexpressed in several types of solid tumors and contributes to epigenetic silencing of tumor suppressor. However, its clinical significance and the molecular mechanisms underlying its regulation in gastric cancer (GC) remain largely unknown. Here, we showed that CUL4B was elevated in GC tissues and its overexpression was positively correlated with poor prognosis and lymph node metastasis. CUL4B knockdown in GC cells decreased proliferation, mesenchymal transition and invasion in vitro, as well as tumor growth and metastasis in nude mice, and CUL4B overexpression induced the opposite results. Further studies showed that miR-101 could inhibit CUL4B expression by directly targeting its 3’-UTR and they were inversely correlated in clinical GC specimens. Notably, a positive relationship between CUL4B and HER2 was found in GC clinical specimens, GC cells and GC xenograft tumors. Through bioinformatics analysis of miRNA-seq data and target prediction, we nominated miR-125a as a direct target of CUL4B. ChIP assays demonstrated that CUL4B directly repressed miR-125a expression by physically binding to its promoter. In addition, we confirmed miR-125a is the target of HER2. Consequently, we demonstrated that CUL4B can up-regulate HER2 expression through repressing miR-125a. Most importantly, silencing of HER2 by Herceptin or siRNA partially reversed CUL4B-induced epithelial-to-mesenchymal transition (EMT), cell invasion and metastasis in vitro and in vivo. These findings define a CUL4B-miR-125a-HER2 regulatory mechanism shed light on CUL4B oncogenic mechanisms and reveals promising therapeutic targets for progressive GC. CUL4B proteins are frequently upregulated in human cancer, yet little is known about the underlying molecular mechanisms of CUL4B induced gastric cancer(GC) carcigenesis.Here, we uncover the critical role of CUL4B in gastric cancer growth and metastasis through the regulation of HER2 expression.CUL4B contributes to GC invasion and metastasis by transcriptional repression of HER2 targeting miR-125a, which provide a new insight into how CUL4B regulates GC progression and metastasis.

Dataset Information

Epithelial deletion of CUL4B increased myeloid-derived suppressor cells-mediated immunosuppression to promote ApcMin/+ tumor formation

Dataset's files

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets