Project description:Glioma stem cells (GSCs) drive propagation and therapeutic resistance of glioblastomas, the most aggressive diffuse brain tumor. However, the molecular mechanisms that maintain the stemness and promote therapy resistance remain poorly understood. Here we study CD109 – STAT3 axis as crucial for the maintenance of stemness and tumorigenicity of GSCs and as a mediator of chemoresistance. Mechanistically, CD109 physically interacts with glycoprotein 130 (GP130) to promote activation of the IL-6/STAT3 pathway in GSCs. Genetic depletion of CD109 abolished the stemness and self-renewal of GSCs and impaired tumorigenicity. Loss of stemness was accompanied with a phenotypic shift of GSCs to more differentiated astrocytic-like cells. Importantly, genetic or pharmacologic targeting of CD109 – STAT3 axis sensitized the GSCs to chemotherapy suggesting that targeting CD109 – STAT3 axis has potential to overcome therapy resistance in glioblastoma.
Project description:In nasopharyngeal carcinoma (NPC), the TGF-β/SMAD pathway genes are altered with inactive TGF-β signal, but the mechanisms remain unclear. Flotillin 2 (FLOT2) is a highly expressed protein in NPC, and is crucial for NPC progression. We show that FLOT2 negatively regulated TGF-β signaling pathway via up-regulating CD109 expression. FLOT2 increased CD109 transcription by stabilizing STAT3, which is identified as the activating transcription factor of CD109. FLOT2 interacted with STAT3 directly and increased the stability of STAT3 by inhibiting K48-linked polyubiquitination. CD109 could rescue the functional changes of NPC cells resulted from FLOT2 alteration. Expression of FLOT2 and CD109 was positively correlated, and was significantly higher in NPC tissues than in the normal nasopharyngeal epithelial tissues. Patients with high expression of both FLOT2 and CD109 presented poorer overall survival and disease-free survival compared those with high expression of one protein alone. In conclusion, FLOT2 promotes the development of NPC by inhibiting TGF-β signaling pathway via stimulating the expression of CD109 by stabilizing STAT3, which provides novel potential therapeutic strategy for NPC treatment.
Project description:CD109 is a glycosylphosphatidylinositol-anchored glycoprotein that is highly expressed in several types of human cancers, particularly squamous cell carcinomas. We previously reported that CD109-deficient mice exhibit epidermal hyperplasia and chronic skin inflammation. Although we found that CD109 regulates differentiation of keratinocytes in vivo, the function of CD109 in tumorigenesis remains unknown. In this study, we investigated the role of CD109 in skin tumorigenesis using a two-stage carcinogenesis model in CD109-deficient mice with chronic skin inflammation.
Project description:CD109 is a glycosylphosphatidylinositol-anchored glycoprotein highly expressed in several types of human malignant tumors including lung cancers. We investigated the in vivo functions of CD109 protein in malignant lung tumors. CD109+/+ and CD109-/- K-ras[LSL-G12D/+];p53[fl/fl] (KP) mice were sacrificed at 20 to 23 weeks of age and total RNA was extracted from the lung tumors. SurePrint G3 Mouse GE Microarray 8×60K Ver.2.0 were performed.
Project description:The primary aim of this project was to identify novel factors, in particular the cell-surface protein CD109, which regulate osteoclastogenesis. Microarray analysis was performed comparing two pre-osteoclast cell lines generated from the RAW 264.7 osteoclast cell line: one that has the capacity to fuse forming large multinucleated cells and one that does not fuse. It was found that CD109 was up-regulated by > 17-fold in the osteoclast forming cell line when compared to the cell line that does not fuse.
Project description:The primary aim of this project was to identify novel factors, in particular the cell-surface protein CD109, which regulate osteoclastogenesis. Microarray analysis was performed comparing two pre-osteoclast cell lines generated from the RAW 264.7 osteoclast cell line: one that has the capacity to fuse forming large multinucleated cells and one that does not fuse. It was found that CD109 was up-regulated by > 17-fold in the osteoclast forming cell line when compared to the cell line that does not fuse. H10 (osteoclastogenic cell line) and C8 (non osteoclastogenic cell line) cells were plated for two days in 60 mm tissue culture dishes at a density of 0.5 x 10^6 in a culture medium consisting of 8 ml of Dulbecco's Modified Eagle Medium (DMEM, Life Technologies, Grand Island, NY, USA) supplemented with 10% Fetal Bovine Serum (FBS) and 10% antibiotics (164 IU/mL of penicillin G, 50 mg/ml of gentamicin, and 0.25 mg/ml of fungizone) as well as purified recombinant RANKL (60ng/ml). Following two days of culture, total RNA was extracted from the H10 and C8 cells (Qiagen RNeasy Minikit, Germantown, MD, USA) and the concentration of extracted RNA was measured (using a nanodrop method). Experiment was done in triplicates
Project description:In order to determine the role of Cd109 in regulating metastatic ability and identify Cd109-dependent transcriptonal targets in metastatic lung adenocarcinoma, we sequenced the mRNA from 3 mouse metastasis cell lines. Each of these cell lines (889PF-shGFP, 889PF-shCd109#1, and 889PF-shCd109#2) were derived from the same parental cell line 889PF. 889PF was derived from the pleural fluid of a Kras LSL G12D, p53 flox/flox 129S1/SvlmJ mouse model of metastatic lung adenocarcinoma. A comparison of shGFP and shCd109 cell lines reveals Cd109-dependent changes in the metastatic transcriptome.
Project description:Perineural invasion (PNI) represents a unique biological feature causing the poor prognosis of pancreatic ductal adenocarcinoma (PDAC), especially with KRAS mutation. Extracellular vesicle (EVs)-packaged circRNAs function as essential mediator for tumor microenviroment communication to trigger PDAC cells invading into the surrounding regions and lead to distant metastasis. However, the regulatory mechanism of exosomal circRNA in PNI of KRAS-mutated PDAC has not been elucidated. Herein, we identified an KRASG12D-mutation responsive exosomal circRNA-circPNIT, which was positively correlated with PNI of PDAC. Functionally, KRASG12D PDAC-derived EV-packaged circPNIT promotes axonogenesis and PNI both in vitro and in vivo. Mechanistically, circPNIT-mediated Rab5B-CD109 interplay bypassed traditional endosomal trafficking to anchor Rab5B in the lipid rafts of multivescular body and fostered the secretion of circPNIT as a cargo of CD109+EVs. Subsequently, CD109+EVs achieved the targeted delivery of circPNIT to neurons by recognizing their surface receptor TRPV1 and facilitated DSCAML1 transcription-induced axonogenesis, which in turn enhanced the PNI by activating GFRα1/RET pathway. Importantly, we established an engineered si-cirPNIT-loaded CD109+EVs to dramatically inhibit PNI of PDAC in a KRASG12D/+ Trp53R172H/+ Pdx-1-Cre mice model. Collectively, Our findings highlight the mechanism underlying EV-packaed circRNA mediating PNI of KRAS mutated-PDAC dependent of a Rab5B endosomal bypass, supporting circPINT as an effective target for the treatment of neuro-metastatic PDAC