Dataset Information

Tetraspanin CD9 interacts with ?-secretase to enhance its oncogenic function in pancreatic cancer.

ABSTRACT: Pancreatic cancer is one of the most lethal cancers and its prognosis remains poor. ADAM family proteins like ADAM10, ADAM9 and ADAM17 function as ?-secretase to cleavage cell surface proteins like Notch to facilitate oncogenesis in various tumors. The oncogenic roles of ?-secretase in PDAC have been demonstrated but it remains unknown that whether and how ?-secretase is regulated in PDAC. Here, we report that the expression of tetraspanin CD9 was increased and strongly associated with poor prognosis in PDAC. CD9 expression was positively associated with ?-secretase activity in PDAC tissues and CD9 knock-down inhibited ?-secretase activity in PDAC cell lines. Co-immunoprecipitation and GST pull down demonstrates that CD9 directly interacted with ADAM10, ADAM9 and ADAM17, respectively. Cell surface biotin labeling and immunostaining of tagged ADAM proteins show that CD9 promoted cell surface trafficking of ADAM family proteins. In addition, the antibody targeting extracellular domain of CD9 disrupted the interactions between CD9 and ADAM family proteins, reduced cell surface trafficking of ADAM proteins and inhibited ?-secretase activity. Notch signaling was inhibited by CD9 knockdown or CD9 antibody in cell lines. Finally, CD9 antibody showed anti-tumor effects in cell proliferation MTT assay, transwell migration assay and colony formation assay. Our study reveals a novel CD9/ADAM/Notch signaling network in PDAC and it supports that targeting CD9-ADAM interaction with antibody may be a potential therapeutic intervention for PDAC.

SUBMITTER: Lu W

PROVIDER: S-EPMC7540085 | biostudies-literature | 2020

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Tetraspanin CD9 interacts with α-secretase to enhance its oncogenic function in pancreatic cancer.

Lu Weiwei W Fei Aihua A Jiang Ying Y Chen Liang L Wang Yunkun Y

American journal of translational research 20200915 9

Pancreatic cancer is one of the most lethal cancers and its prognosis remains poor. ADAM family proteins like ADAM10, ADAM9 and ADAM17 function as α-secretase to cleavage cell surface proteins like Notch to facilitate oncogenesis in various tumors. The oncogenic roles of α-secretase in PDAC have been demonstrated but it remains unknown that whether and how α-secretase is regulated in PDAC. Here, we report that the expression of tetraspanin CD9 was increased and strongly associated with poor prog ...[more]

PMID: 33042435

Similar Datasets

Project description:Tetraspanins are a family of proteins with four transmembrane domains that associate between themselves and cluster with other partner proteins, conforming a distinct class of membrane domains, the tetraspanin-enriched microdomains (TEMs). These TEMs constitute macromolecular signaling platforms that regulate key processes in several cellular settings controlling signaling thresholds and avidity of receptors. In this study, we investigated the role of CD9, a tetraspanin that regulates major biological processes such as cell migration and immunological responses, in two mouse models of colitis that have been used to study the pathogenesis of inflammatory bowel disease (IBD). Previous in vitro studies revealed an important role in the interaction of leukocytes with inflamed endothelium, but in vivo evidence of the involvement of CD9 in inflammatory diseases is scarce. Here, we studied the role of CD9 in the pathogenesis of colitis in vivo. Colitis was induced by administration of dextran sodium sulfate (DSS), a chemical colitogen that causes epithelial disruption and intestinal inflammation. CD9-/- mice showed less severe colitis than wild-type counterparts upon exposure to DSS (2% solution) and enhanced survival in response to a lethal DSS dose (4%). Decreased neutrophil and macrophage cell infiltration was observed in colonic tissue from CD9-/- animals, in accordance with their lower serum levels of TNF-?, IL-6, and other proinflammatory cytokines in the colon. The specific role of CD9 in IBD was further dissected by transfer of CD4+ CD45RBhi naive T cells into the Rag1-/- mouse colitis model. However, no significant differences were observed in these settings between both groups, ruling out a role for CD9 in IBD in the lymphoid compartment. Experiments with bone marrow chimeras revealed that CD9 in the non-hematopoietic compartment is involved in colon injury and limits the proliferation of epithelial cells. Our data indicate that CD9 in non-hematopoietic cells plays an important role in colitis by limiting epithelial cell proliferation. Future strategies to repress CD9 expression may be of therapeutic benefit in the treatment of IBD.

Project description:Tetraspanin protein CD9 supports sperm-egg fusion, and regulates cell adhesion, motility, metastasis, proliferation and signaling. The large extracellular loop and transmembrane domains of CD9 engage in functionally important interactions with partner proteins. However, neither functional nor biochemical roles have been shown for the CD9 C-terminal tail, despite it being highly conserved throughout vertebrate species. To gain new insight into the CD9 tail, three C-terminal amino acids (Glu-Met-Val) were replaced with residues corresponding to C-terminal amino acids from tetraspanin protein CD82 (Pro-Lys-Tyr). Wild-type and mutant CD9 were then stably expressed in MOLT-4, K562, U937, RD and HT1080 cells. Whereas wild-type CD9 inhibited cell adhesion and spreading on fibronectin, mutant CD9 did not. Wild-type CD9 also promoted homotypic cell-cell aggregation and microvilli formation, whereas mutant CD9 did not. Protein interactions of wild-type and mutant CD9 were compared quantitatively using stable isotope labeling with amino acids in cell culture (SILAC) in conjunction with liquid-chromatography-tandem mass spectrometry (LC-MS/MS) technology. SILAC results showed that, despite wild-type and mutant CD9 having identical expression levels, mutant CD9 and its major transmembrane interacting partners were recovered in substantially reduced amounts from 1% Brij 96 lysates. Immunoprecipitation experiments confirmed that mutant CD9 recovery was decreased in Brij 96, but not in more stringent Triton X-100 detergent. Additionally, compared with wild-type CD9 complexes, mutant CD9 complexes were larger and more oligomerized in Brij 96 detergent, consistent with decreased Brij 96 solubility, perhaps due to more membrane domains packing more tightly together. In conclusion, multiple CD9 functions depend on its C-terminal tail, which affects the molecular organization of CD9 complexes, as manifested by their altered solubilization in Brij 96 and organization on the cell surface.

Dataset Information

Tetraspanin CD9 interacts with ?-secretase to enhance its oncogenic function in pancreatic cancer.

Publications

Tetraspanin CD9 interacts with α-secretase to enhance its oncogenic function in pancreatic cancer.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets