Han-jie Liu

Glioma is a fatal brain tumor characterized by rapid proliferation and treatment resistance. Ferroptosis is a newly discovered programmed cell death and plays a crucial role in the occurrence and progression of tumors. In this study, we identified ferroptosis specific markers to reveal the relationship between ferroptosis-related genes and glioma by analyzing whole transcriptome data from Chinese Glioma Genome Atlas, The Cancer Genome Atlas dataset, GSE16011 dataset, and the Repository of Molecular Brain Neoplasia Data dataset. Nineteen ferroptosis-related genes with clinical and pathological features of glioma were identified as highly correlated. Functional assays in glioma cell lines indicated the association of ferroptosis with temozolomide resistance, autophagy, and glioma cell migration. Therefore, the identified ferroptosis-related genes were significantly correlated with glioma progression.

PURPOSE: Autophagy plays a vital role in cancer initiation, malignant progression, and resistance to treatment; however, autophagy-related gene sets have rarely been analyzed in glioblastoma. The purpose of this study was to evaluate the prognostic significance of autophagy-related genes in patients with glioblastoma. PATIENTS AND METHODS: Here, we collected whole transcriptome expression data from the Chinese Glioma Genome Atlas (CGGA) and The Cancer Genome Atlas (TCGA) datasets to explore the relationship between autophagy-related gene expression and glioblastoma prognosis. R language was the primary analysis and drawing tool. RESULTS: We screened 531 autophagy-related genes and identified 14 associated with overall survival in data from 986 patients with glioblastoma. Patients could be clustered into two groups (high and low risk) using expression data from the 14 associated genes, based on significant differences in clinicopathology and prognosis. Next, we constructed a signature based on the 14 genes and found that most patients designated high risk using our gene signature were IDH wild-type, MGMT promoter non-methylated, and likely to have more malignant tumor subtypes (including classical and mesenchymal subtypes). Survival analysis indicated that patients in the high-risk group had dramatically shorter overall survival compared with their low-risk counterparts. Cox regression analysis further confirmed the independent prognostic value of our 14 gene signature. Moreover, functional and ESTIMATE analyses revealed enrichment of immune and inflammatory responses in the high-risk group. CONCLUSION: In this study, we identified a novel autophagy-related signature for the prediction of prognosis in patients with glioblastoma.

BACKGROUND/AIMS: Sulforaphane-N-acetyl-cysteine (SFN-NAC) is a sulforaphane (SFN) metabolite with a longer half-life and better blood-brain barrier permeability than those of SFN. Previous studies have found that SFN-NAC can act via ERK to destroy microtubules and inhibit cell growth in lung cancer cells. However, the underlying mechanisms are unclear, and it is unknown whether SFN-NAC can inhibit the growth of glioma. Here, we have demonstrated for the first time that SFN-NAC activates autophagy-mediated downregulation of α-tubulin expression via the ERK pathway. METHODS: U87MG and U373MG cells, two widely used glioma cell lines, were utilized in this study. Apoptosis assay, western blot analysis, co-immunoprecipitation, immunostaining, and electron microscopy were used to analyze the effect of SFN-NAC on α-tubulin and its interaction with microtube-associated protein 1 light-chain 3 (LC3). RESULTS: SFN-NAC induced cell-cycle arrest in the G2/M phase and dose-dependently induced intracellular ERK activation, autophagy, and α-tubulin downregulation. These SFN-NAC-induced effects were reversed by inhibiting the ERK pathway with its inhibitor PD98059. U87MG and U373MG cells were transfected with LC3 small interfering RNA, and the subsequent inhibition of autophagy reversed the downregulation of α-tubulin by SFN-NAC. Furthermore, co-immunoprecipitation experiments and confocal microscopy confirmed that SFN-NAC promotes the binding of LC3 with α-tubulin in the cytoplasm. Cell viability experiments demonstrate that SFN-NAC inhibits the growth of U87MG and U373MG cell colonies. CONCLUSION: These findings suggest that SFN-NAC is a novel potential anti-glioma agent.

Objective Astrocytes constitute approximately 30% of cells in gliomas and play important roles in synapse construction and survival. Recently, JAK/STAT pathway activation associated with a new type of astrocyte was reported. However, the implications of these tumor-associated reactive astrocytes (TARAs) in glioma are not known. Methods We comprehensively assessed TARAs in gliomas, both in single cells and at the bulk tumor level, by analyzing five independent datasets. First, we analyzed two single-cell RNA sequencing datasets of 35,563 cells from 23 patients to estimate the infiltration level of TARAs in gliomas. Second, we collected clinical information and genomic and transcriptomic data of 1,379 diffuse astrocytoma and glioblastoma samples from the Chinese Glioma Genome Atlas (CGGA) and The Cancer Genome Atlas datasets to evaluate the genomic, transcriptomic and clinical characteristics of TARA infiltration. Third, we downloaded expression profiles of recurrent glioblastoma samples from patients receiving PD-1 inhibitors to analyze the predictive value of TARAs for immune checkpoint inhibition. Results Single-cell RNA sequencing data showed TARAs were abundant in the glioma micro-environment (15.7% in the CGGA dataset and 9.1% in the Gene Expression Omnibus GSE141383 dataset, respectively). Bulk tumor sequencing data showed that the extent of TARA infiltration was highly associated with major clinical and molecular features of astrocytic gliomas. Patients with more TARA infiltration were more likely to have MUC16 , FLG , and PICK3A mutations, chromosome 9p21.3, 10q23.3, and 13q14.2 deletions and 7p11.2 amplification. Gene Ontology analysis revealed that the high level of astrocyte infiltration was characterized by immune and oncogenic pathways, such as the inflammatory response, positive regulation of the JAK–STAT cascade, positive regulation of NIK/NF-kappa B signaling and the tumor necrosis factor biosynthetic process. Patients with greater TARA infiltration showed inferior prognosis. Meanwhile, the extent of reactive astrocyte infiltration exhibited a predictive value for recurrent glioblastoma patients undergoing anti-PD-1 immune therapy. Conclusion TARA infiltration might promote glioma tumor progression and can be used as a diagnostic, predictive and prognostic marker in gliomas. Prevention of TARA infiltration might be a new therapeutic strategy for glioma.