BACKGROUND: Temozolomide (TMZ) resistance is a significant challenge in treating glioblastoma (GBM). Collagen remodeling has been shown to be a critical factor for therapy resistance in other cancers. This study aimed to investigate the mechanism of TMZ chemoresistance by GBM cells reprogramming collagens. METHODS: Key extracellular matrix components, including collagens, were examined in paired primary and recurrent GBM samples as well as in TMZ-treated spontaneous and grafted GBM murine models. Human GBM cell lines (U251, TS667) and mouse primary GBM cells were used for in vitro studies. RNA-sequencing analysis, chromatin immunoprecipitation, immunoprecipitation-mass spectrometry, and co-immunoprecipitation assays were conducted to explore the mechanisms involved in collagen accumulation. A series of in vitro and in vivo experiments were designed to assess the role of the collagen regulators prolyl 4-hydroxylase subunit alpha 1 (P4HA1) and yes-associated protein (YAP) in sensitizing GBM cells to TMZ. RESULTS: This study revealed that TMZ exposure significantly elevated collagen type I (COL I) expression in both GBM patients and murine models. Collagen accumulation sustained GBM cell survival under TMZ-induced stress, contributing to enhanced TMZ resistance. Mechanistically, P4HA1 directly binded to and hydroxylated YAP, preventing ubiquitination-mediated YAP degradation. Stabilized YAP robustly drove collagen type I alpha 1 ( COL1A1) transcription, leading to increased collagen deposition. Disruption of the P4HA1-YAP axis effectively reduced COL I deposition, sensitized GBM cells to TMZ, and significantly improved mouse survival. CONCLUSION P4HA1 maintained YAP-mediated COL1A1 transcription, leading to collagen accumulation and promoting chemoresistance in GBM.
Temozolomide ; Humans ; Glioblastoma/drug therapy* ; Animals ; Mice ; Cell Line, Tumor ; Drug Resistance, Neoplasm/genetics* ; YAP-Signaling Proteins ; Hydroxylation ; Dacarbazine/pharmacology* ; Adaptor Proteins, Signal Transducing/metabolism* ; Transcription Factors/metabolism* ; Collagen/biosynthesis* ; Collagen Type I/metabolism* ; Prolyl Hydroxylases/metabolism* ; Antineoplastic Agents, Alkylating/therapeutic use*

OBJECTIVES: To investigate the mechanism by which circ_EPHB4 regulates temozolomide (TMZ) sensitivity of glioma cells through the miR-424-5p/Wnt3 signal axis. METHODS: We detected the expression levels of circ_EPHB4, miR-424-5p and Wnt3 mRNA in glioma specimens from 25 patients with primary glioma and 25 patients experiencing relapse following temozolomide-based chemotherapy and in TMZ-sensitive and -resistant glioma A172 and SHG44 cells with circ_EPHB4 knockdown using qRT-PCR, and Wnt3 protein expression level was detected with Western blotting. Cell viability, colony-forming ability, and apoptosis of the cells with circ_EPHB4 knockdown were assessed, and the targeted regulation relationship between circ_EPHB4, miR-424-5p, and Wnt3 was verified by dual luciferase reporter assay and RNA immunoprecipitation (RIP) experiments. The effect of circ_EPHB4 knockdown on tumorigenesis of glioma cells was evaluated in subcutaneous tumor-bearing nude mouse models. RESULTS: The expression of circ_EPHB4 was significantly increased in glioma tissues and cells as compared with normal neural tissues and astrocytes (P=0.014). In TMZ-resistant glioma cells, circ_EPHB4 knockdown resulted in an obvious reduction of IC50 value of TMZ, inhibited cell colony formation, and promoted cell apoptosis, and these effects were reversed by miR-424-5p knockdown. The expressions of miR-424-5p and circ_EPHB4 were negatively correlated in glioma tissues (P=0.011). MiR-424-5p knockdown also attenuated the effect of circ_EPHB4 knockdown on expressions of PCNA, P-gp, MRP1 and bax. CONCLUSIONS Circ_EPHB4 regulates Wnt3 expression through "sponge adsorption" of miR-424-5p, thereby modulating TMZ-resistant glioblastoma cell clonogenesis, apoptosis, and TMZ sensitivity, suggesting the potential of circ_EPHB4 as a therapeutic target for reversing drug resistance of gliomas.
MicroRNAs/genetics* ; Humans ; Temozolomide ; Glioma/genetics* ; Animals ; Mice, Nude ; Cell Line, Tumor ; Wnt3 Protein/metabolism* ; Mice ; Apoptosis ; RNA, Circular ; Drug Resistance, Neoplasm ; Brain Neoplasms/pathology* ; Signal Transduction

MAGED4B belongs to the melanoma-associated antigen family; originally found in melanoma, it is expressed in various types of cancer, and is especially enriched in glioblastoma. However, the functional role and molecular mechanisms of MAGED4B in glioma are still unclear. In this study, we found that the MAGED4B level was higher in glioma tissue than that in non-cancer tissue, and the level was positively correlated with glioma grade, tumor diameter, Ki-67 level, and patient age. The patients with higher levels had a worse prognosis than those with lower MAGED4B levels. In glioma cells, MAGED4B overexpression promoted proliferation, invasion, and migration, as well as decreasing apoptosis and the chemosensitivity to cisplatin and temozolomide. On the contrary, MAGED4B knockdown in glioma cells inhibited proliferation, invasion, and migration, as well as increasing apoptosis and the chemosensitivity to cisplatin and temozolomide. MAGED4B knockdown also inhibited the growth of gliomas implanted into the rat brain. The interaction between MAGED4B and tripartite motif-containing 27 (TRIM27) in glioma cells was detected by co-immunoprecipitation assay, which showed that MAGED4B was co-localized with TRIM27. In addition, MAGED4B overexpression down-regulated the TRIM27 protein level, and this was blocked by carbobenzoxyl-L-leucyl-L-leucyl-L-leucine (MG132), an inhibitor of the proteasome. On the contrary, MAGED4B knockdown up-regulated the TRIM27 level. Furthermore, MAGED4B overexpression increased TRIM27 ubiquitination in the presence of MG132. Accordingly, MAGED4B down-regulated the protein levels of genes downstream of ubiquitin-specific protease 7 (USP7) involved in the tumor necrosis factor-alpha (TNF-α)-induced apoptotic pathway. These findings indicate that MAGED4B promotes glioma growth via a TRIM27/USP7/receptor-interacting serine/threonine-protein kinase 1 (RIP1)-dependent TNF-α-induced apoptotic pathway, which suggests that MAGED4B is a potential target for glioma diagnosis and treatment.
Humans ; Tumor Necrosis Factor-alpha ; DNA-Binding Proteins/metabolism* ; Ubiquitin-Specific Peptidase 7 ; Cisplatin ; Temozolomide ; Transcription Factors ; Glioma ; Cell Proliferation ; Melanoma ; Cell Line, Tumor ; Apoptosis ; Nuclear Proteins/genetics*

OBJECTIVE: To explore the short-term efficacy and adverse reactions of orelabrutinib combined with high-dose methotrexate (HD-MTX) in the first-line treatment of elderly high-risk primary central nervous system lymphoma (PCNSL), as well as the survival of patients. METHODS: Twenty-five elderly patients with high-risk primary central nervous system diffuse large B-cell lymphoma admitted to Fujian Provincial Hospital from June 2016 to June 2022 were enrolled in this study, and complete clinical data from all patients were collected retrospectively, and the cut-off for follow-up was December 2022. 15 patients had received temmozolomide combined with HD-MTX regimen for at least four cycles, sequential lenalidomide maintenance therapy, while 10 patients had received orelabrutinib combined with HD-MTX regimen for at least four cycles, sequential orelabrutinib maintenance therapy. The short-term efficacy and adverse reactions of the two groups of patients after treatment were observed. Kaplan-Meier was used to analyze the progression-free survival (PFS) and time to progression (TTP). RESULTS: The objective response rate (ORR) and 2-year median FPS of orelabrutinib combined with HD-MTX regimen group were similar to the temozolomide combined with HD-MTX regimen group (ORR: 100% vs 66.7%; 2-year median PFS: 16 months vs 15 months, P>0.05). The 2-year median TTP of the orelabrutinib+HD-MTX regimen group was better than that of the temozolomide+HD-MTX regimen group (not reached vs 12 months, P<0.05). There were no significant differences in adverse reactions such as gastrointestinal reactions, bone marrow suppression, liver and kidney damage, cardiotoxicity, pneumonia and bleeding between these two groups (P>0.05). CONCLUSION For elderly patients with high-risk PCNSL, orelabrutinib combined with HD-MTX has reliable short-term efficacy, good safety, and tolerable adverse reactions, which is worthy of clinical promotion.
Humans ; Aged ; Methotrexate/adverse effects* ; Retrospective Studies ; Temozolomide/therapeutic use* ; Central Nervous System Neoplasms/drug therapy* ; Antineoplastic Combined Chemotherapy Protocols ; Lymphoma, Large B-Cell, Diffuse/drug therapy* ; Central Nervous System

To explore the role of forkhead box protein O1 (FOXO1) in the progression of glioblastoma multiforme (GBM) and related drug resistance, we deciphered the roles of FOXO1 and miR-506 in proliferation, apoptosis, migration, invasion, autophagy, and temozolomide (TMZ) sensitivity in the U251 cell line using in vitro and in vivo experiments. Cell viability was tested by a cell counting kit-8 (CCK8) kit; migration and invasion were checked by the scratching assay; apoptosis was evaluated by terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) staining and flow cytometry. The construction of plasmids and dual-luciferase reporter experiment were carried out to find the interaction site between FOXO1 and miR-506. Immunohistochemistry was done to check the protein level in tumors after the in vivo experiment. We found that the FOXO1-miR-506 axis suppresses GBM cell invasion and migration and promotes GBM chemosensitivity to TMZ, which was mediated by autophagy. FOXO1 upregulates miR-506 by binding to its promoter to enhance transcriptional activation. MiR-506 could downregulate E26 transformation-specific 1 (ETS1) expression by targeting its 3'-untranslated region (UTR). Interestingly, ETS1 promoted FOXO1 translocation from the nucleus to the cytosol and further suppressed the FOXO1-miR-506 axis in GBM cells. Consistently, both miR-506 inhibition and ETS1 overexpression could rescue FOXO1 overactivation-mediated TMZ chemosensitivity in mouse models. Our study demonstrated a negative feedback loop of FOXO1/miR-506/ETS1/FOXO1 in GBM in regulating invasiveness and chemosensitivity. Thus, the above axis might be a promising therapeutic target for GBM.
Animals ; Mice ; Brain Neoplasms/genetics* ; Cell Line, Tumor ; Cell Proliferation ; Drug Resistance, Neoplasm ; Feedback ; Gene Expression Regulation, Neoplastic ; Glioblastoma/metabolism* ; MicroRNAs/metabolism* ; Temozolomide/therapeutic use* ; Humans ; Forkhead Box Protein O1/metabolism*

Objective: To investigate the function of primary cilia in regulating the cellular response to temozolomide (TMZ) and ionizing radiation (IR) in glioblastoma (GBM). Methods: GBM cells were treated with TMZ or X-ray/carbon ion. The primary cilia were examined by immunostaining with Arl13b and γ-tubulin, and the cellular resistance ability was measured by cell viability assay or survival fraction assay. Combining with cilia ablation by IFT88 depletion or chloral hydrate and induction by lithium chloride, the autophagy was measured by acridine orange staining assay. The DNA damage repair ability was estimated by the kinetic curve of γH2AX foci, and the DNA-dependent protein kinase (DNA-PK) activation was detected by immunostaining assay. Results: Primary cilia were frequently preserved in GBM, and the induction of ciliogenesis decreased cell proliferation. TMZ and IR promoted ciliogenesis in dose- and time-dependent manners, and the suppression of ciliogenesis significantly enhanced the cellular sensitivity to TMZ and IR. The inhibition of ciliogenesis elevated the lethal effects of TMZ and IR via the impairment of autophagy and DNA damage repair. The interference of ciliogenesis reduced DNA-PK activation, and the knockdown of DNA-PK led to cilium formation and elongation. Conclusion Primary cilia play a vital role in regulating the cellular sensitivity to TMZ and IR in GBM cells through mediating autophagy and DNA damage repair.
Antineoplastic Agents, Alkylating/therapeutic use* ; Brain Neoplasms/metabolism* ; Cell Line, Tumor ; DNA/therapeutic use* ; Glioblastoma/metabolism* ; Humans ; Radiation, Ionizing ; Temozolomide/therapeutic use*

OBJECTIVE: To investigate the clinical efficacy of high dose methotrexate (HD-MTX), temozolomide (TMZ), and rituximab (R) in the treatment of patients with primary central nervous system lymphoma (PCNSL). METHODS: Clinical data of patients with PCNSL diagnosed and treated in Guangdong Provincial People's Hospital from February 2010 to May 2017 were collected. First, patients were given 6-8 cycles of MTX (3.5 g/m RESULTS: There were 42 patients enrolled in the study, 17 cases in HD-MTX+TMZ group and 25 cases in HD-MTX+TMZ+R group. The median PFS and OS times in HD-MTX+TMZ+R group were 56.7 months and N/A, respectively, while, 7.3 months and 34.7 months in HD-MTX+TMZ group, respectively. In addition, there was no significant difference in median survival between patients who received TMZ maintenance therapy and those who were only actively monitored. During the induction period, all the patients had grade 1-2 nausea and vomiting, while in the consolidation treatment period, no grade 3/4 toxicity was observed. CONCLUSION The combination of HD-MTX+TMZ+R in the treatment of PCNSL patients shows a definite short-term effect, which can increase the survival rate of the patients. The side effects are mild, and the patients can generally tolerate.
Antineoplastic Combined Chemotherapy Protocols ; Central Nervous System ; Central Nervous System Neoplasms/drug therapy* ; Humans ; Lymphoma, Non-Hodgkin/drug therapy* ; Methotrexate/therapeutic use* ; Retrospective Studies ; Rituximab/therapeutic use* ; Temozolomide/therapeutic use* ; Treatment Outcome

OBJECTIVE: To establish a mouse model bearing orthotopic temozolomide (TMZ)-resistant glioma that mimics the development of drug resistance in gliomas METHODS: Seventy-eight adult C57BL/6 mice were randomly divided into 6 groups ( RESULTS: The mouse models bearing TMZresistant glioma was successfully established. The cells from the high-dose induced group showed a significantly higher colony-forming rate than those from the high-dose control group ( CONCLUSIONS Progressive increase of TMZ doses in mice bearing orthotopic gliomas can effectively induce TMZ resistance of the gliomas.
Animals ; Antineoplastic Agents, Alkylating/pharmacology* ; Brain Neoplasms/drug therapy* ; Cell Line, Tumor ; Disease Models, Animal ; Drug Resistance, Neoplasm ; Glioma/drug therapy* ; Mice ; Mice, Inbred C57BL ; Temozolomide/therapeutic use*

Apoptosis ; Ascorbic Acid/pharmacology* ; Brain Neoplasms ; Cell Line, Tumor ; Glioma ; Humans ; Temozolomide/pharmacology*

In gliomas, the canonical Wingless/Int (WNT)/β-catenin pathway is increased while peroxisome proliferator-activated receptor gamma (PPAR-γ) is downregulated. The two systems act in an opposite manner. This review focuses on the interplay between WNT/β-catenin signaling and PPAR-γ and their metabolic implications as potential therapeutic target in gliomas. Activation of the WNT/β-catenin pathway stimulates the transcription of genes involved in proliferation, invasion, nucleotide synthesis, tumor growth, and angiogenesis. Activation of PPAR-γ agonists inhibits various signaling pathways such as the JAK/STAT, WNT/β-catenin, and PI3K/Akt pathways, which reduces tumor growth, cell proliferation, cell invasiveness, and angiogenesis. Nonsteroidal anti-inflammatory drugs, curcumin, antipsychotic drugs, adiponectin, and sulforaphane downregulate the WNT/β-catenin pathway through the upregulation of PPAR-γ and thus appear to provide an interesting therapeutic approach for gliomas. Temozolomide (TMZ) is an antiangiogenic agent. The downstream action of this opposite interplay may explain the TMZ-resistance often reported in gliomas.
Animals ; Brain Neoplasms ; metabolism ; therapy ; Dacarbazine ; analogs & derivatives ; pharmacology ; Down-Regulation ; drug effects ; Glioma ; metabolism ; therapy ; Humans ; PPAR gamma ; metabolism ; Temozolomide ; Wnt Signaling Pathway ; drug effects ; physiology