Glioma stem cells reconstruct similar immunoinflammatory microenvironment in different transplant sites and induce malignant transformation of tumor microenvironment cells

Cordycepin Enhanced Therapeutic Potential of Gemcitabine against Cholangiocarcinoma via Downregulating Cancer Stem-Like Properties

Cordycepin, a valuable bioactive component isolated from Cordyceps militaris, has been reported to possess anti-cancer potential and the property to enhance the effects of chemotherapeutic agents in various types of cancers. However, the ability of cordycepin to chemosensitize cholangiocarcinoma (CCA) cells to gemcitabine has not yet been evaluated. The current study was performed to evaluate the above, and the mechanisms associated with it. The study analyzed the effects of cordycepin in combination with gemcitabine on the cancer stem-like properties of the CCA SNU478 cell line, including its anti-apoptotic, migratory, and antioxidant effects. In addition, the combination of cordycepin and gemcitabine was evaluated in the CCA xenograft model. The cordycepin treatment significantly decreased SNU478 cell viability and, in combination with gemcitabine, additively reduced cell viability. The cordycepin and gemcitabine co-treatment significantly increased the Annexin V+ population and downregulated B-cell lymphoma 2 (Bcl-2) expression, suggesting that the decreased cell viability in the cordycepin+gemcitabine group may result from an increase in apoptotic death. In addition, the cordycepin and gemcitabine co-treatment significantly reduced the migratory ability of SNU478 cells in the wound healing and trans-well migration assays. It was observed that the cordycepin and gemcitabine cotreatment reduced the CD44highCD133high population in SNU478 cells and the expression level of sex determining region Y-box 2 (Sox-2), indicating the downregulation of the cancer stem-like population. Cordycepin also enhanced oxidative damage mediated by gemcitabine in MitoSOX staining associated with the upregulated Kelch like ECH Associated Protein 1 (Keap1)/nuclear factor erythroid 2-related factor 2 (Nrf2) expression ratio. In the SNU478 xenograft model, co-administration of cordycepin and gemcitabine additively delayed tumor growth. These results indicate that cordycepin potentiates the chemotherapeutic property of gemcitabine against CCA, which results from the downregulation of its cancer-stem-like properties. Hence, the combination therapy of cordycepin and gemcitabine may be a promising therapeutic strategy in the treatment of CCA.

Machine learning unveils immune-related signature in multicenter glioma studies

In glioma molecular subtyping, existing biomarkers are limited, prompting the development of new ones. We present a multicenter study-derived consensus immune-related and prognostic gene signature (CIPS) using an optimal risk score model and 101 algorithms. CIPS, an independent risk factor, showed stable and powerful predictive performance for overall and progression-free survival, surpassing traditional clinical variables. The risk score correlated significantly with the immune microenvironment, indicating potential sensitivity to immunotherapy. High-risk groups exhibited distinct chemotherapy drug sensitivity. Seven signature genes, including IGFBP2 and TNFRSF12A, were validated by qRT-PCR, with higher expression in tumors and prognostic relevance. TNFRSF12A, upregulated in GBM, demonstrated inhibitory effects on glioma cell proliferation, migration, and invasion. CIPS emerges as a robust tool for enhancing individual glioma patient outcomes, while IGFBP2 and TNFRSF12A pose as promising tumor markers and therapeutic targets.

Long noncoding RNA HOXC-AS3 remodels lipid metabolism and promotes the proliferation of transformed macrophages in the glioma stem cell microenvironment by regulating the hnRNPA1/CaM axis

Metabolism remodelling of macrophages in the glioblastoma microenvironment contributes to immunotherapeutic resistance. However, glioma stem cell (GSC)-initiated lipid metabolism remodelling of transformed macrophages (tMΦs) and its effect on the glioblastoma microenvironment have not been fully elucidated. Total cholesterol (TC) levels and lipid metabolism enzyme expression in macrophages in the GSC microenvironment were evaluated and found that the TC levels of tMΦs were increased, and the expression of the lipid metabolism enzymes calmodulin (CaM), apolipoprotein E (ApoE), and liver X receptor (LXR) was upregulated. Knockdown of HOXC-AS3 led to a decrease in the proliferation, colony formation, invasiveness, and tumorigenicity of tMΦs. Downregulation of CaM resulted in a decline in TC levels. HOXC-AS3 overexpression led to increases in both CaM expression levels and TC levels in tMΦs. RNA pull down and mass spectrometry experiments were conducted and heterogeneous nuclear ribonucleoprotein A1 (hnRNPA1) was screened as the HOXC-AS3 binding proteins related to lipid metabolism. RIP and RNA pull down assays verified that HOXC-AS3 can form a complex with hnRNPA1. Knockdown of hnRNPA1 downregulated CaM expression; however, downregulation of HOXC-AS3 did not affect hnRNPA1 expression.TMΦs underwent lipid metabolism remodelling induced by GSC via the HOXC-AS3/hnRNPA1/CaM pathway, which enhanced the protumor activities of tMΦs, and may serve as a potential metabolic intervening target to improve glioblastoma immunotherapy.

Targeting Tumor-Associated Antigen: A Promising CAR-T Therapeutic Strategy for Glioblastoma Treatment

Chimeric antigen receptor T cells (CAR-T) therapy is a prospective therapeutic strategy for blood cancers tumor, especially leukemia, but it is not effective for solid tumors. Glioblastoma (GBM) is a highly immunosuppressive and deadly malignant tumor with poor responses to immunotherapies. Although CAR-T therapeutic strategies were used for glioma in preclinical trials, the current proliferation activity of CAR-T is not sufficient, and malignant glioma usually recruit immunosuppressive cells to form a tumor microenvironment that hinders CAR-T infiltration, depletes CAR-T, and impairs their efficacy. Moreover, specific environments such as hypoxia and nutritional deficiency can hinder the killing effect of CAR-T, limiting their therapeutic effect. The normal brain lack lymphocytes, but CAR-T usually can recognize specific antigens and regulate the tumor immune microenvironment to increase and decrease pro- and anti-inflammatory factors, respectively. This increases the number of T cells and ultimately enhances anti-tumor effects. CAR-T therapy has become an indispensable modality for glioma due to the specific tumor-associated antigens (TAAs). This review describes the characteristics of CAR-T specific antigen recognition and changing tumor immune microenvironment, as well as ongoing research into CAR-T therapy targeting TAAs in GBM and their potential clinical application.

Comprehensive analysis of inhibitory checkpoint ligand expression by glioblastoma cells

Glioblastoma is a highly aggressive brain malignancy commonly refractory to classical and novel chemo-, radio- and immunotherapies, with median survival times of ~15 months following diagnosis. Poor immunological responses exemplified by the downregulation of T-cell activity, and upregulation of immunosuppressive cells within the tumor microenvironment have limited the effectiveness of immunotherapy in glioblastoma to date. Here we show that glioblastoma cells express a large repertoire of inhibitory checkpoint ligands known to control effector T cell responses. Furthermore, flow cytometry analysis reveals that glioblastoma cells with an enhanced stem cell-like phenotype express several investigated ligands at significant levels on their cell surface. This reveals that glioblastoma stem-like cells express suppressive ligands with the potential of suppressing major T cell checkpoint receptors. With this information, it is now essential that we understand the relevance of this extensive repertoire of immune checkpoint ligands and their functional consequence on immune evasion in glioblastoma. This is necessary to develop effective immunotherapeutics and to be able to match treatment to patient, especially in the light of CheckMate 143.

Immune-Related lncRNA Correlated with Transcription Factors Provide Strong Prognostic Prediction in Gliomas

Glioma is the most common and deadly tumor in central nervous system. According to previous studies, long noncoding RNAs (lncRNA) and transcription factors were significant factors of gliomas progression by regulating gliomas immune microenvironment. In our study, we built two independent cohorts from CGGA and TCGA. And we extracted 253 immune-related lncRNA correlated with prognosis. After LASSO analysis and multivariate Cox regression analysis, 8 immune-related lncRNA were used to construct classifier. The effectiveness of classifier was confirmed in both CGGA (AUC = 0.869) and TCGA (AUC = 0.902) cohorts. The correlation between transcription factors and immune-related lncRNA was calculated by WCGNA. Eventually, we built a network between 8 lncRNA and transcription factors. The function of core immune-related lncRNA in gliomas immune microenvironment was also investigated by CIBERTSORT. Our research provided a strong classifier of immune-related lncRNA to predict gliomas patient outcome. We also found the correlation between core immune-related lncRNA and transcription factors. These results may stimulate new strategy of immunotherapy in gliomas patients.

Novel enhanced GFP-positive congenic inbred strain establishment and application of tumor-bearing nude mouse model

Transgenic GFP gene mice are widely used. Given the unique advantages of immunodeficient animals in the field of oncology research, we aim to establish a nude mouse inbred strain that stably expresses enhanced GFP (EGFP) for use in transplanted tumor microenvironment (TME) research. Female C57BL/6-Tg(CAG-EGFP) mice were backcrossed with male BALB/c nude mice for 11 generations. The genotype and phenotype of novel inbred strain Foxn1nu .B6-Tg(CAG-EGFP) were identified by biochemical loci detection, skin transplantation and flow cytometry. PCR and fluorescence spectrophotometry were performed to evaluate the relative expression of EGFP in different parts of the brain. Red fluorescence protein (RFP) gene was stably transfected into human glioma stem cells (GSC), SU3, which were then transplanted intracerebrally or ectopically into Foxn1nu .B6-Tg(CAG-EGFP) mice. Cell co-expression of EGFP and RFP in transplanted tissues was further analyzed with the Live Cell Imaging System (Cell'R, Olympus) and FISH. The inbred strain Foxn1nu .B6-Tg(CAG-EGFP) shows different levels of EGFP expression in brain tissue. The hematological and immune cells of the inbred strain mice were close to those of nude mice. EGFP was stably expressed in multiple sites of Foxn1nu .B6-Tg(CAG-EGFP) mice, including brain tissue. With the dual-fluorescence tracing transplanted tumor model, we found that SU3 induced host cell malignant transformation in TME, and tumor/host cell fusion. In conclusion, EGFP is differentially and widely expressed in brain tissue of Foxn1nu .B6-Tg(CAG-EGFP), which is an ideal model for TME investigation. With Foxn1nu .B6-Tg(CAG-EGFP) mice, our research demonstrated that host cell malignant transformation and tumor/host cell fusion play an important role in tumor progression.

Advances and potential pitfalls of oncolytic viruses expressing immunomodulatory transgene therapy for malignant gliomas

Glioblastoma (GBM) is an immunosuppressive, lethal brain tumor. Despite advances in molecular understanding and therapies, the clinical benefits have remained limited, and the life expectancy of patients with GBM has only been extended to ~15 months. Currently, genetically modified oncolytic viruses (OV) that express immunomodulatory transgenes constitute a research hot spot in the field of glioma treatment. An oncolytic virus is designed to selectively target, infect, and replicate in tumor cells while sparing normal tissues. Moreover, many studies have shown therapeutic advantages, and recent clinical trials have demonstrated the safety and efficacy of their usage. However, the therapeutic efficacy of oncolytic viruses alone is limited, while oncolytic viruses expressing immunomodulatory transgenes are more potent inducers of immunity and enhance immune cell-mediated antitumor immune responses in GBM. An increasing number of basic studies on oncolytic viruses encoding immunomodulatory transgene therapy for malignant gliomas have yielded beneficial outcomes. Oncolytic viruses that are armed with immunomodulatory transgenes remain promising as a therapy against malignant gliomas and will undoubtedly provide new insights into possible clinical uses or strategies. In this review, we summarize the research advances related to oncolytic viruses that express immunomodulatory transgenes, as well as potential treatment pitfalls in patients with malignant gliomas.

3-Bromopyruvate inhibits the malignant phenotype of malignantly transformed macrophages and dendritic cells induced by glioma stem cells in the glioma microenvironment via miR-449a/MCT1

Bromopyruvate (3-BrPA) is a glycolysis inhibitor that has been reported to have a strong anti-tumour effect in many human tumours. Several studies have reported that 3-BrPA could inhibit glioma progression; however, its role on the interstitial cells in the glioma microenvironment has not been investigated. In previous studies, we found that in the glioma microenvironment, glioma stem cells can induce the malignant transformation of macrophages and dendritic cells. In this study, we focused on the effects of 3-BrPA on malignantly transformed macrophages and dendritic cells. First, we found that 3-BrPA inhibited the proliferation of malignantly transformed macrophages and dendritic cells in a dose-dependent and time-dependent manner. Further study indicated that 3-BrPA significantly decreased extracellular lactate and inhibited the clone formation, migration and invasion of malignantly transformed macrophages and dendritic cells. Using an online database and a series of experiments, we demonstrated that 3-BrPA inhibits the malignant progression of malignantly transformed macrophages and dendritic cells via the miR-449a/MCT1 axis. These findings built experimental basis for new approach against glioma.

Prostate carcinoma cell-derived exosomal MicroRNA-26a modulates the metastasis and tumor growth of prostate carcinoma

Prostate carcinoma may develop into metastatic castration-resistant prostate carcinoma (mCRPC) after endocrine therapy. Exosomal microRNAs play an important role in the regulation of tumor microenvironment. Our study aimed to investigate the effect of exosomal miR-26a on tumor phenotype of prostate carcinoma. Low-grade prostate carcinoma cell line (LNCAP) and mCRPC cell line (PC-3) were treated as experimental subjects according to their miR-26a expressions. Wound healing, transwell and colony-forming unit assays were performed after miR-26a mimic/inhibitor transfection. Then, exosomes were isolated from LNCAP and PC-3 cells, and the levels of exosomal miR-26a were determined. After co-culture of LNCAP (PC-3) cells with PC-3 (LNCAP) exosomes, changes in malignant behaviors were measured. Moreover, LNCAP/PC-3 exosomes were injected into xenograft tumor mice to determine effects of the exosomes on tumorigenicity of LNCAP and PC-3 cells. MiR-26a showed a potently inhibitory effect on cell proliferation, migration and invasion of LNCAP and PC-3 cells. LNCAP exosomes had a higher miR-26a level, compared with PC-3 exosomes. Overexpression of miR-26a attenuated the enhanced malignant behavior of LNCAP cells induced by PC-3 exosomes, and miR-26a inhibition could reverse the inhibitory effects of LNCAP exosomes on PC-3 cells. Exosomal miR-26a could significantly alter the expressions of epithelial-mesenchymal transition (EMT)-related factors. Moreover, LNCAP exosomes suppressed the tumorigenicity of PC-3 cells, while PC-3 exosomes could promote the tumorigenicity of LNCAP cells. Our data suggest that exosomal miR-26a derived from prostate carcinoma cells had a suppressive effect on the metastasis and tumor growth of prostate carcinoma.