Adenovirus infection promotes the formation of glioma stem cells from glioblastoma cells through the TLR9/NEAT1/STAT3 pathway

Abstract

Background: Glioma stem cells (GSCs) are glioma cells with stemness and are responsible for a variety of malignant behaviors of glioma. Evidence has shown that signals from tumor microenvironment (TME) enhance stemness of glioma cells. However, identification of the signaling molecules and underlying mechanisms has not been completely elucidated. Methods: Human samples and glioma cell lines were cultured in vitro to determine the effects of adenovirus (ADV) infection by sphere formation, RT-qPCR, western blotting, FACS and immunofluorescence. For in vivo analysis, mouse intracranial tumor model was applied. Bioinformatics analysis, gene knockdown by siRNA, RT-qPCR and western blotting were applied for further mechanistic studies. Results: Infection of patient-derived glioma cells with ADV increases the formation of tumor spheres. ADV infection upregulated stem cell markers and in turn promoted the capacities of self-renewal and multi-lineage differentiation of the infected tumor spheres. These ADV infected tumor spheres had stronger potential to form xenograft tumors in immune-compromised mice. GSCs formation could be promoted by ADV infection via TLR9, because TLR9 was upregulated after ADV infection, and knockdown of TLR9 reduced ADV-induced GSCs. Consistently, MYD88, as well as total STAT3 and phosphorylated (p-)STAT3, were also upregulated in ADV-induced GSCs. Knockdown of MYD88 or pharmaceutical inhibition of STAT3 attenuated stemness of ADV-induced GSCs. Moreover, we found that ADV infection upregulated lncRNA NEAT1. Knockdown of NEAT1 impaired stemness of ADV-induced GSCs. Lastly, HMGB1, a damage associated molecular pattern (DAMP) that triggers TLR signaling, also upregulated stemness markers in glioma cells.

Temozolomide Treatment Induces HMGB1 to Promote the Formation of Glioma Stem Cells via the TLR2/NEAT1/Wnt Pathway in Glioblastoma

“…GSEA analysis showed that HMGB1 upregulated pluripotency-related genes in GBM cells ( Supplementary Figures 1C,D ), consistent with previously reports (Zang et al, 2020 ). We then cultured GBM cells with different concentrations of HMGB1, and determined the formation of tumor spheres under the neural sphere culture condition.…”

“…HMGB1, a well-known DAMP released by damaged cells, is reported to upregulate pluripotency-related genes in GBM cells (Zang et al, 2020 ). We then asked whether TMZ treatment could promote the expression of HMGB1.…”

“…Culture of biopsy-derived GBM cells has been described previously (Zang et al, 2020 ). Tumor tissues were collected from GBM patients accepting neurosurgery at Xijing Hospital, with signed informed consent and approved by the Ethics Committee of Xijing Hospital for use of human samples.…”

MRC2 overexpression combined with intronic hypomethylation: potential predictors for glioma

“…The relevant signal pathways include TLRs signal pathway, NK cell mediated cytotoxicity signal pathway and JAK-STAT signal pathway. TLRs signal pathway involves MYD88dependent or non-dependent mediations, former process stimulates proliferation in gliomas by inducing overexpression of proin ammatory factors 24,25 ; HLA-A existed in NK cell mediated cytotoxic signal pathway mainly encodes mammalian histocompatibility antigen, which could inhibit the antigen recognition process, reduce the immune response and cytotoxicity, and nally enhances tumor cell immune escape 26,27 ; JAK-STAT signal pathway and STAT3 were related to the release of antiin ammatory cytokines and the immunosuppressive environment in glioma, and participated in cell proliferation, differentiation, in ammation and tumorigenesis 28,29 .…”

An Overview of the Role of Long Non-Coding RNAs in Human Choriocarcinoma

“…OCT4 is a stemness-related transcription factor, which regulates the expression of both the lncRNAs NEAT1 and MALAT1 to promote the progress of lung cancer [ 28 ]. Moreover, NEAT1 leads to stem-like phenotypes in NSCLC, TNBC, and GBM cells [ 29 , 30 , 31 ]. The lncRNA B4GALT1-AS1 recruits the yes-associated protein (YAP) to the nucleus, a potent oncogene related to several oncogenic programs, including stemness.…”