Causal relationship between inflammatory proteins and glioblastoma: a two-sample bi­directional mendelian randomization study.

Background: Observational studies have indicated a potential correlation between glioblastoma and circulating inflammatory proteins. Further investigation is required to establish a causal relationship between these two factors. Methods: We performed a Mendelian randomization (MR) analysis using genome-wide association study (GWAS) summary of 91 circulating inflammation-related proteins (N = 14,824) to assess their causal impact on glioblastoma. The GWAS summary data for glioblastoma included 243 cases and 287,137 controls. The inverse variance weighted (IVW) method was used as the primary analytical method to assess causality. Four additional MR methods [simple mode, MR-Egger, weighted median, and weighted mode] were used to supplement the IVW results. Furthermore, several sensitivity analyses were performed to assess heterogeneity, horizontal pleiotropy, and stability. Reverse MR analysis was also performed. glioblastoma transcriptomic data from The Cancer Genome Atlas (TCGA) were analyzed to validate the findings obtained through MR, while pathway and functional enrichment analyses were conducted to predict the potential underlying mechanisms. Results: Our findings from employing the inverse variance weighted method in our forward MR analysis provide robust evidence supporting a potential association between glioblastoma and elevated levels of Cystatin D, as well as decreased levels of fibroblast growth factor 21 (FGF21) in the circulation. Moreover, our reverse MR analysis revealed that glioblastoma may contribute to increased concentrations of C-X-C motif chemokine 9 (CXCL9) and Interleukin-33 (IL-33) in the bloodstream. Transcriptomic analysis showed that FGF21 expression was inversely associated with the risk of developing glioblastoma, whereas an increased risk was linked to elevated levels of CXCL9 and IL-33. Pathway and functional enrichment analyses suggested that Cystatin D might exert its effects on glioblastoma through intracellular protein transport, whereas FGF21 might affect glioblastoma via glucose response mechanisms. Conclusion: These results indicate that FGF21 is a significant factor in glioblastoma susceptibility. Glioblastoma also affects the expression of inflammatory proteins such as C-X-C motif chemokine 9 and Interleukin-33, providing new insights into the mechanisms of glioblastoma genesis and clinical research.

ScRNA-seq reveals novel immune-suppressive T cells and investigates CMV-TCR-T cells cytotoxicity against GBM.

BACKGROUND: Glioblastoma (GBM) is a fatal primary brain malignancy in adults. Previous studies have shown that cytomegalovirus (CMV) is a risk factor for tumorigenesis and aggressiveness for glioblastoma. However, little is known about how CMV infection affects immune cells in the tumor microenvironment of GBM. Furthermore, there has been almost no engineered T-cell receptor (TCR)-T targeting CMV for GBM research to date. METHODS: We evaluated the CMV infection status of patients with GBM's tumor tissue by immune electron microscopy, immunofluorescence, and droplet digital PCR. We performed single-cell RNA sequencing for CMV-infected GBM to investigate the effects of CMV on the GBM immune microenvironment. CellChat was applied to analyze the interaction between cells in the GBM tumor microenvironment. Additionally, we conducted single-cell TCR/B cell receptor (BCR) sequencing and Grouping of Lymphocyte Interactions with Paratope Hotspots 2 algorithms to acquire specific CMV-TCR sequences. Genetic engineering was used to introduce CMV-TCR into primary T cells derived from patients with CMV-infected GBM. Flow cytometry was used to measure the proportion and cytotoxicity status of T cells in vitro. RESULTS: We identified two novel immune cell subpopulations in CMV-infected GBM, which were bipositive CD68+SOX2+ tumor-associated macrophages and FXYD6+ T cells. We highlighted that the interaction between bipositive TAMs or cancer cells and T cells was predominantly focused on FXYD6+ T cells rather than regulatory T cells (Tregs), whereas, FXYD6+ T cells were further identified as a group of novel immunosuppressive T cells. CMV-TCR-T cells showed significant therapeutic effects on the human-derived orthotopic GBM mice model. CONCLUSIONS: These findings provided an insight into the underlying mechanism of CMV infection promoting the GBM immunosuppression, and provided a novel potential immunotherapy strategy for patients with GBM.

An Investigation of the Immune Microenvironment and Genome during Lung Adenocarcinoma Development.

Background: Adenocarcinoma in situ (AIS) and minimally invasive adenocarcinoma (MIA) are two consecutive pathological processes that occur before invasive lung adenocarcinoma (LUAD). However, our understanding of the immune editing patterns during the progression of LUAD remains limited. Furthermore, we know very little about whether alterations in driver genes are involved in forming the tumor microenvironment (TME). Therefore, it is necessary to elucidate the regulatory role of TME in LUAD development from multiple dimensions, including immune cell infiltration, molecular mutation events, and oncogenic signaling pathways. Methods: We collected 145 surgically resected pulmonary nodule specimens, including 28 cases of AIS, 52 cases of MIA, and 65 cases of LUAD. Immunohistochemistry (IHC) was used to detect the expression of immune markers CD3, CD4, CD8, CD68 and programmed death ligand 1 (PD-L1). Genomic data and TMB generated by targeted next-generation sequencing (NGS). Results: LUAD exhibited higher levels of immune cell infiltration, tumor mutation burden (TMB), and activation of oncogenic pathways compared to AIS and MIA. In LUAD, compared to epidermal growth factor receptor (EGFR) single mutation and wild-type (WT) samples, cases with EGFR co-mutations showed a more pronounced rise in the CD4/CD8 ratio and CD68 infiltration. Patients with low-density lipoprotein (LDL) receptor-related protein 1B (LRP1B) mutation have higher TMB and PD-L1 expression. The transition from AIS to LUAD tends to shift the TME towards the PD-L1+CD8+ subtype (adaptive resistance). Progression-associated mutations (PAMs) were enriched in the lymphocyte differentiation pathway and related to exhausted cells' phenotype. Conclusion: Tumor-infiltrating immune cells tend to accumulate as the depth of LUAD invasion increases, but subsequently develop into an immune exhaustion and immune escape state. Mutations in EGFR and LRP1B could potentially establish an immune niche that fosters tumor growth. PAMs in LUAD may accelerate disease progression by promoting T cell differentiation into an exhausted state.

Chronic stress as an emerging risk factor for the development and progression of glioma.

ABSTRACT: Gliomas tend to have a poor prognosis and are the most common primary malignant tumors of the central nervous system. Compared with patients with other cancers, glioma patients often suffer from increased levels of psychological stress, such as anxiety and fear. Chronic stress (CS) is thought to impact glioma profoundly. However, because of the complex mechanisms underlying CS and variability in individual tolerance, the role of CS in glioma remains unclear. This review suggests a new proposal to redivide the stress system into two parts. Neuronal activity is dominant upstream. Stress-signaling molecules produced by the neuroendocrine system are dominant downstream. We discuss the underlying molecular mechanisms by which CS impacts glioma. Potential pharmacological treatments are also summarized from the therapeutic perspective of CS.

Lung microbiome alterations in NSCLC patients.

Lung is colonized by a diverse array of microbes and the lung microbiota is profoundly involved in the development of respiratory diseases. There is little knowledge about the role of lung microbiota dysbiosis in lung cancer. In this study, we performed metagenomic sequencing on bronchoalveolar lavage (BAL) from two different sampling methods in non-small cell lung cancer (NSCLC) patients and non-cancer controls. We found the obvious variation between bronchoscopy samples and lobectomy samples. Oral taxa can be found in both bronchoscopy and lobectomy samples and higher abundance of oral taxa can be found in bronchoscopy samples. Although the NSCLC patients had similar microbial communities with non-cancer controls, rare species such as Lactobacillus rossiae, Bacteroides pyogenes, Paenibacillus odorifer, Pseudomonas entomophila, Magnetospirillum gryphiswaldense, fungus Chaetomium globosum et al. showed obvious difference between NSCLC patients and non-cancer controls. Age-, gender-, and smoking-specific species and EGFR expression-related species in NSCLC patients were detected. There results implicated that different lung segments have differential lung microbiome composition. The oral taxa are found in the lobectomy samples suggesting that oral microbiota are the true members of lung microbiota, rather than contamination during bronchoscopy. Lung cancer does not obviously alter the global microbial composition, while rare species are altered more than common species. Certain microbes may be associated with lung cancer progression.

A four-factor immune risk score signature predicts the clinical outcome of patients with spinal chordoma.

BACKGROUND: Currently, the measurement of immune cells in previous studies is usually subjective, and no immune-based prognostic model has been established for chordoma. In this study, we sought to simultaneously measure tumor-infiltrating lymphocyte (TIL) subtypes in chordoma samples using an objective method and develop an immune risk score (IRS) model for survival prediction. METHODS: Multiplexed quantitative immunofluorescence staining was used to determine the TIL levels in the tumoral and stromal subareas of 114 spinal chordoma specimens (54 in the training and 60 in the validation cohort) for programmed death-1 (PD-1), CD3, CD8, CD20 (where CD is cluster of differentiation), and FOXP3. Flow cytometry was performed to validate the immunofluorescence assay for lymphocyte measurement on an additional five fresh chordoma specimens. Subsequently, the IRS model was built using the least absolute shrinkage and selection operator (LASSO) Cox regression method. RESULTS: Flow cytometry and quantitative immunofluorescence showed similar lymphocytic percentages and TIL subpopulation proportions in the fresh tumor specimens. With the training data, the LASSO model identified four immune features for IRS construction: tumoral FOXP3, tumoral PD-1, stromal FOXP3, and stromal CD8. In both cohorts, a high IRS was significantly associated with tumoral programmed cell death-1 ligand 1 expression, Enneking inappropriate tumor resection, and surrounding muscle invasion by tumor. Multivariate Cox regression and stratified analysis in the two cohorts revealed that the IRS was an independent predictor and could effectively separate patients with similar Enneking staging into different risk subgroups, with significantly different survival rates. Further receiver operating characteristic analysis found that the IRS classifier had a better prognostic value than the traditional clinicopathological factors and compensated for the deficiency of Enneking staging for outcome prediction. More importantly, a nomogram based on the IRS and clinical predictors showed adequate performance in estimating disease recurrence and survival of patients. CONCLUSIONS: These data support the use of the IRS signature as a reliable prognostic tool in spinal chordoma and may facilitate individualized therapy decision making for patients.

Corrigendum: Coagulation Factor X Regulated by CASC2c Recruited Macrophages and Induced M2 Polarization in Glioblastoma Multiforme.

[This corrects the article DOI: 10.3389/fimmu.2018.01557.].

LRRC4 Suppresses E-Cadherin-Dependent Collective Cell Invasion and Metastasis in Epithelial Ovarian Cancer.

Epithelial ovarian cancer (EOC) is the most malignant gynecological carcinoma and is of a high incidence of death due to detection at late stages when metastasis already occurs. However, the mechanism underlying metastasis of EOC remains unclear. Analysis of the open database and experiments with immunochemistry showed that LRRC4 is lowly expressed in high-grade serous ovarian cancer (HGSC) cells and during EOC metastasis. The 3D cell culture system and the orthotopic ovarian xenograft model infected with LRRC4-containing adeno-associated virus serotype 9 (AAV9) were used to confirm collective invasion and metastasis of cells in vitro and in vivo. Phos-tag SDS-PAGE was used to detect the phosphorylation of LRRC4 and PIK3R1. A number of experiments with methods such as co-immunoprecipitation and immunoblotting were performed to explore the mechanism for the actions of LRRC4 and PIK3R1 in EOC metastasis. An inverse correlation between LRRC4 and E-cadherin expression was detected in the regions of invasion in primary EOC tissues and metastatic ascites. LRRC4 binds to the cSH2 domain of PIK3R1 and inhibits the activity of PIK3R1, without disrupting the physical interactions between PIK3R1 and PIK3CA. LRRC4 inhibits EOC metastasis by targeting E-cadherin-dependent collective cell invasion and does so by inhibiting the PIK3R1-mediated AKT/GSK3ß/ß-catenin signaling pathway. LRRC4 functions as a tumor suppressor gene to inhibit EOC collective invasion and metastasis in vitro and in vivo and does so by directly binding to the cSH2 domain of PIK3R1 to exert its regulatory function. Our findings provide a potential novel approach for metastasis prognosis and a new strategy for the treatment of EOC.

Clinicopathological characteristics of dysplastic teratomous neuroglia with anti-N-methyl-d-aspartate receptor encephalitis.

In this study, we investigated whether unique pathological characteristics exist in teratomas that can trigger autoimmune anti-N-methyl-d-aspartate receptor (NMDAR) encephalitis. We compared a case of retroperitoneal teratoma associated with anti-NMDAR encephalitis and four control cases. The encephalitis-positive case showed that (i) more dysplastic neuroglia with higher Ki-67 labeling index values than the control cases, which met the diagnostic criteria of astrocytoma, (ii) the NMDAR subunit NR1 was expressed more abundantly in neuroglial tissue where many neuroglial cells co-expressed glial fibrillary acidic protein (GFAP) and NR1 and formed abnormally large cellular masses, (iii) intense NR1 expression occurs in squamous epithelium near neuroglial tissue and lymphocyte infiltration. This study showed that dysplastic neuroglial tissue resembling central nervous system tumors, which might promote autoimmunity, distinguished the case with NMDAR encephalitis from the controls. Additionally, abnormal expression of NR1 occurs in non-neural tissues and could be triggered by inflammation and participate in autoimmunity.

The Relationship Between Tumor-Stroma Ratio, the Immune Microenvironment, and Survival in Patients With Spinal Chordoma.

BACKGROUND: Currently, little is known about the clinical relevance of tumor-stroma ratio (TSR) in chordoma and data discussing the relationship between TSR and immune status of chordoma are lacking. OBJECTIVE: To characterize TSR distribution in spinal chordoma, and investigated its correlation with clinicopathologic or immunological features of patients and outcome. METHODS: TSR was assessed visually on hematoxylin and eosin-stained sections from 54 tumor specimens by 2 independent pathologists. Multiplex immunofluorescence was used to quantify the expression levels of microvessel density, Ki-67, Brachyury, and tumor as well as stromal PD-L1. Tumor immunity status including the Immunoscore and densities of tumor-infiltrating lymphocytes (TILs) subtypes were obtained from our published data and reanalyzed. RESULTS: Bland-Altman plot showed no difference between mean TSR derived from the two observers. TSR was positively associated with stromal PD-L1 expression, the Immunoscore and CD3+ as well as CD4+ TILs density, but negatively correlated with tumor microvessel density, Ki-67 index, surrounding muscle invasion by tumor and number of Foxp3+ and PD-1+ TILs. Low TSR independently predicted poor local recurrence-free survival and overall survival. Moreover, patients with low TSR and low Immunoscore chordoma phenotype were associated with the worst survival. More importantly, combined TSR and Immunoscore accurately reflected prognosis and enhanced the ability of TSR or Immunoscore alone for outcome prediction. CONCLUSION: These data reveal the significant impact of TSR on tumor progression and immunological response of patients. Subsequent use of agents targeting the stroma compartment may be an effective strategy to treat chordoma especially in combination with immune-based drugs.

Clinicopathological and Prognostic Characteristics in Extra-Axial Chordomas: An Integrative Analysis of 86 Cases and Comparison With Axial Chordomas.

BACKGROUND: Currently, clinical characteristics and prognostic factors of extra-axial chordoma (EAC) remain poorly understood. OBJECTIVE: To characterize clinicopathological characteristics in a large EAC cohort and investigate their correlation with survival. We also attempted to compare these outcomes with axial chordoma (AC). METHODS: Medline and Embase searches (from inception to February 28, 2018) were conducted to identify eligible studies as per predefined criteria. The local database at our center was also retrospectively reviewed to include additional patients. RESULTS: Forty-three studies from the literature and 86 patients from our local institute were identified, resulting in a total of 86 EAC patients and 75 AC patients for analysis. Overall, EAC had similar characteristics to AC, except for having higher CAM5.2 expression, common lobular growth pattern, and better prognosis. Whereas wide surgical resection was consistently associated with favorable survival in both EAC and AC cohorts on univariate analyses, most parameters showed differential prognostic implications between the 2 groups. Significant prognostic factors for local recurrence-free survival on multivariate analysis included type of surgery in both cohorts and tumor Brachyury expression and adjuvant radiotherapy in AC cohort. Multivariate analysis of overall survival demonstrated that type of surgery, tumor Brachyury expression, and duration of symptoms were significant predictors in the AC cohort, whereas none of the analyzed parameters were predictive of overall survival for the EAC group. CONCLUSION: These data suggest potentially distinct biological behaviors between EAC and AC and may provide useful information to better understand the prognostic characteristics and improve the outcome prediction of EAC patients.

Eutopic endometrium from patients with endometriosis modulates the expression of CD36 and SIRP-α in peritoneal macrophages.

AIM: This study aimed to investigate the in vitro alterations of the expression of signal regulatory protein-α (SIRP-α) and CD36 in macrophages in the endometriosis condition. METHODS: The expression of SIRP-α and CD36 was measured in peritoneal macrophages and peripheral blood mononuclear cells of endometriosis patients and control participants. The expressions of SIRP-α and CD36 were measured in human acute monocytic leukemia (THP-1) cell-derived macrophages that were treated with interleukin-6 (IL-6)-induced conditioned medium, eutopic versus normal endometrial homogenate, or lipopolysaccharide in the presence or absence of nuclear factor kappa-B (NF-κB) or transforming growth factor (TGF-ß) inhibitors, respectively. RESULTS: Peritoneal macrophages that were isolated from women with endometriosis exhibited an enhanced expression of SIRP-α and a decreased expression of CD36 compared to control participants. Women with endometriosis had significantly higher levels of SIRP-α and CD36 in peripheral circulating mononuclear cells than in control participants. SIRP-α expression was significantly increased, whereas the CD36 expression was decreased in THP-1 cell-derived macrophages after treatment with eutopic endometrial homogenate. Intervention with IL-6-induced conditioned medium resulted in the downregulation of SIRP-α but the upregulation of CD36 in THP-1 cells. Incubation with the NF-κBp50 inhibitor decreased the expression of CD36 and SIRP-α in macrophages that were treated with normal endometrial homogenate, whereas the TGF-ß inhibitor enhanced the CD36 expression of THP-1 cell-derived macrophages treated with eutopic endometrial homogenate. CONCLUSION: The eutopic endometrium could reduce the phagocytic ability of peritoneal macrophages in women with endometriosis through the modulation of SIRP-α and CD36 expression. Inhibition of the TGF-ß signal pathway may be a potential therapeutic target for the treatment of endometriosis.

Clinical Impact of the Immune Microenvironment in Spinal Chordoma: Immunoscore as an Independent Favorable Prognostic Factor.

BACKGROUND: Currently, clinical implications of immune system cells in chordoma remain to be elucidated. OBJECTIVE: To characterize in situ immune cell infiltrates, the Immunoscore, and investigate their correlation with clinicopathologic data of spinal chordoma patients and outcome. METHODS: Tumor-infiltrating lymphocytes (TILs) subtypes were assessed in 54 tumor specimens using immunohistochemistry for CD3, CD4, CD8, CD20, Foxp3, PD-1, and PD-L1. RESULTS: Overall, immune cell infiltrates were present in all samples and there was low or moderate correlation among several TILs subsets. PD-1+ TILs density, CD3+, and CD8+ TILs densities in the tumor interior (TI) subarea were associated with surrounding muscle invasion by tumor, whereas PD-L1+ TILs showed inverse association with tumor pathological grade and stage. The density of PD-1+ TILs, PD-L1+ TILs, CD4+ TILs, and CD3+ TILs both in the TI and combined tumor regions (TI and invasion margin) were significantly associated with local recurrence-free survival and overall survival (OS). However, Foxp3+ TILs (P = .024) and CD8+ TILs evaluated in the TI (P < .001) only correlated with OS. The Immunoscore predicted less aggressive clinical features and favorable outcomes. Patients with an Immunoscore of 4 had a median OS of 128 mo, while I0 (Immunoscore of 0) patients survived only 27 mo. Multivariate analysis demonstrated that the Immunoscore was an independent favorable prognostic factor of both local recurrence-free survival (P = .026) and OS (P = .046). CONCLUSION: Our data suggest a clinically relevant role of the immune microenvironment in spinal chordoma and identify the Immunoscore as promising prognostic marker.

Hypermethylated gene ANKDD1A is a candidate tumor suppressor that interacts with FIH1 and decreases HIF1α stability to inhibit cell autophagy in the glioblastoma multiforme hypoxia microenvironment.

Ectopic epigenetic mechanisms play important roles in facilitating tumorigenesis. Here, we first demonstrated that ANKDD1A is a functional tumor suppressor gene, especially in the hypoxia microenvironment. ANKDD1A directly interacts with FIH1 and inhibits the transcriptional activity of HIF1α by upregulating FIH1. In addition, ANKDD1A decreases the half-life of HIF1α by upregulating FIH1, decreases glucose uptake and lactate production, inhibits glioblastoma multiforme (GBM) autophagy, and induces apoptosis in GBM cells under hypoxia. Moreover, ANKDD1A is highly frequently methylated in GBM. The tumor-specific methylation of ANKDD1A indicates that it could be used as a potential epigenetic biomarker as well as a possible therapeutic target.

Mature cardiac myocytohamartoma: a case report and review of literature.

Mature cardiac myocyte hamartoma is a kind of cardiac benign tumor which is extremely rare. Here, we reported the case of a 41-year-old male with cough and shortness of breath. The positron emission tomography computed tomography (PET-CT) showed one tumor in the right atrium, and then the patient had an operation to remove the tumor. Finally, we diagnosed this case as hamartoma of mature cardiac myocytes by histopathology and immunophenotype and also review the tumor which has been published in the literature.

Serum and Ectopic Endometrium from Women with Endometriosis Modulate Macrophage M1/M2 Polarization via the Smad2/Smad3 Pathway.

OBJECTIVE: This study investigated the alterations in macrophage polarization in patients with endometriosis as well as the underlying molecular mechanisms. METHODS: Peritoneal washings, serum samples, and endometrial tissues were collected from endometriosis patients and control subjects. Endometrial stromal cells (ESCs) were isolated from endometrial tissue, and conditioned medium was prepared by treating ESCs with or without various concentrations of interleukin- (IL-) 6, estrogen, or progestin. The frequencies of CD86+ and CD163+ cells and expression levels of these markers as well as the cytokines IL-12 and IL-10 were measured in THP-1- (human monocytic leukemia cell) derived macrophages. RESULTS: There was a decrease in the percentage of CD86+ macrophages in the peritoneal wash solution of patients with endometriosis. Ectopic endometrial homogenates could promote M1 to M2 macrophage polarization in response to lipopolysaccharide (LPS), as evidenced by the increased percentage of CD163+ macrophages and increased IL-10 expression as well as a decreased percentage of CD86+ cells and lower IL-12 expression. In contrast, addition of serum from women with endometriosis to THP-1 cells resulted in the polarization of macrophages towards both M1 and M2 phenotypes. Upregulation of Smad2/Smad3 in macrophages upon exposure to eutopic and ectopic endometrial homogenates as well as serum of women with endometriosis was observed, and blockage of Smad2/Smad3 with their inhibitor SB431542 could reverse the macrophage polarization from M1 to M2. Conditioned medium induced by IL-6, but neither estrogen nor progestin, could facilitate M2 polarization. Neutralization of IL-6 diminished macrophage M2 polarization in endometriosis. CONCLUSION: This study provides detailed evidence supporting alterations in M1 to M2 macrophage polarization that may contribute to the initiation as well as progression of endometriosis.

LINC00470 Coordinates the Epigenetic Regulation of ELFN2 to Distract GBM Cell Autophagy.

The epigenetics and genomics of glioblastoma (GBM) are complicated. Previous reports indicate that ELFN2 is widely distributed in the cerebral cortex neurons, striatum, and hippocampus cone and in granular cells. However, the function and mechanism of ELFN2, particularly in GBM, have rarely been explored. In this study, we identified ELFN2 as a new hypomethylation gene that acts as an oncogene in GBM. ELFN2 promoted cell autophagy by interacting with AurkA and eIF2α and inhibiting the activation of AurkA. We also demonstrated that aberrantly high ELFN2 expression is obtained due to hypomethylation of its promoter and abnormal miR-101 and LINC00470 expression in GBM. LINC00470 not only enhanced the expression of ELFN2 through adsorption of miR-101 but also affected the methylation level of ELFN2 by decreasing H3K27me3 occupancy. In addition, LINC00470 played a dominant role in the regulation of GBM cell autophagy, even though it upregulated ELFN2 expression. The results indicate that the combination of LINC00470 and ELFN2 has important significance for evaluating the prognosis of astrocytoma patients.

Coagulation Factor X Regulated by CASC2c Recruited Macrophages and Induced M2 Polarization in Glioblastoma Multiforme.

Tumor-associated macrophages (TAMs) constitute a major component of inflammatory cells in the glioblastoma multiforme (GBM) tumor microenvironment. TAMs have been implicated in GBM angiogenesis, invasion, local tumor recurrence, and immunosuppression. Coagulation factor X (FX) is a vitamin K-dependent plasma protein that plays a role in the regulation of blood coagulation. In this study, we first found that FX was highly expressed and positively correlated with TAM density in human GBM. FX exhibited a potent chemotactic capacity to recruit macrophages and promoted macrophages toward M2 subtype polarization, accelerating GBM growth. FX bound to extracellular signal-related kinase (ERK)1/2 and inhibited p-ERK1/2 in GBM cells. FX was secreted in the tumor microenvironment and increased the phosphorylation and activation of ERK1/2 and AKT in macrophages, which may have been responsible for the M2 subtype macrophage polarization. Moreover, although the lncRNA CASC2c has been verified to function as a miR-101 competing endogenous RNA (ceRNA) to promote miR-101 target genes in GBM cells, we first confirmed that CASC2c did not function as a miR-338-3p ceRNA to promote FX expression, and that FX was a target gene of miR-338-3p. CASC2c interacted with and reciprocally repressed miR-338-3p. Both CASC2c and miR-388-3p bound to FX and commonly inhibited its expression and secretion. CASC2c repressed M2 subtype macrophage polarization. Taken together, our findings revealed a novel mechanism highlighting CASC2c and FX as potential therapeutic targets to improve GBM patients by altering the GBM microenvironment.

A cytoplasmic long noncoding RNA LINC00470 as a new AKT activator to mediate glioblastoma cell autophagy.

BACKGROUND: Despite the overwhelming number of investigations on AKT, little is known about lncRNA on AKT regulation, especially in GBM cells. METHODS: RNA-binding protein immunoprecipitation assay (RIP) and RNA pulldown were used to confirm the binding of LINC00470 and fused in sarcoma (FUS). Confocal imaging, co-immunoprecipitation (Co-IP) and GST pulldown assays were used to detect the interaction between FUS and AKT. EdU assay, CCK-8 assay, and intracranial xenograft assays were performed to demonstrate the effect of LINC00470 on the malignant phenotype of GBM cells. RT-qPCR and Western blotting were performed to test the effect of LINC00470 on AKT and pAKT. RESULTS: In this study, we demonstrated that LINC00470 was a positive regulator for AKT activation in GBM. LINC00470 bound to FUS and AKT to form a ternary complex, anchoring FUS in the cytoplasm to increase AKT activity. Higher pAKT activated by LINC00470 inhibited ubiquitination of HK1, which affected glycolysis, and inhibited cell autophagy. Furthermore, higher LINC00470 expression was associated with GBM tumorigenesis and poor patient prognosis. CONCLUSIONS: Our findings revealed a noncanonical AKT activation signaling pathway, i.e., LINC00470 directly interacts with FUS, serving as an AKT activator to promote GBM progression. LINC00470 has an important referential significance to evaluate the prognosis of patients.