Current progress of anti­PD­1/PDL1 immunotherapy for glioblastoma (Review).

Glioblastoma (GBM) is the most common central nervous system malignancy in adults. GBM may be classified as grade IV diffuse astrocytoma according to the 2021 World Health Organization revised classification of central nervous system tumors, which means it is the most aggressive, invasive, undifferentiated type of tumor. Immune checkpoint blockade (ICB), particularly anti­programmed cell death protein­1 (PD­1)/PD­1 ligand­1 immunotherapy, has been confirmed to be successful across several tumor types. However, in GBM, this treatment is still uncommon and the efficacy is unpredictable, and <10% of patients show long­term responses. Recently, numerous studies have been conducted to explore what factors may indicate or affect the ICB response rate in GBM, including molecular alterations, immune expression signatures and immune infiltration. The present review aimed to summarize the current progress to improve the understanding of immunotherapy for GBM.

Analysis of DWI in the classification of glioma pathology and its therapeutic application in clinical surgery: a case-control study.

Background: Glioma is a common primary craniocerebral malignant tumor, due to the lack of specificity of imaging examination and clinical manifestations, its diagnostic accuracy is relatively low, which may result in misdiagnosis and missed diagnosis. The apparent diffusion coefficient (ADC) in magnetic resonance diffusion weighted imaging (DWI) can reflect the histological characteristics of gliomas, which can be widely applied to classify gliomas and evaluate the extent of metastasis of glioma. The present study aimed to assess the clinical value of magnetic resonance DWI in the pathological grading of glioma and its therapeutic application in clinical surgery. Methods: This article retrospectively analyzed the clinical data of 41 patients with glioma confirmed by surgical pathology results from January 1, 2019 to March 31, 2020 in the People's Hospital of Gaozhou. Among them, 16 patients had low-grade gliomas [World Health Organization (WHO) grade I-II] and 25 patients had high-grade gliomas (WHO grade III-IV). They were subjected to conventional T1WI and T2WI plain scans, along with DWI and enhanced scans before surgery. The ADC values of the glioma parenchyma, the peritumoral edema area, the surrounding white matter, and the contralateral normal white matter were measured. We selected some tumor tissues for pathological analysis as well, and conducted pathological grading according to WHO grading standards. Results: We compared and evaluated the ADC values of the observed areas for low-grade gliomas and high-grade gliomas. The ADC values of low-grade gliomas in the tumor parenchyma, peritumoral edema, and white matter around the edema area were significantly lower than those of high-grade gliomas, and the differences were statistically significant (P<0.05). The difference in ADC values of normal white matter between the two groups of patients was not statistically significant (P=0.125). Conclusions: DWI has prognostic predictive value in the preoperative differential diagnosis and pathological classification of gliomas. This advanced technology can verify the extent of glioma infiltration in the surrounding brain tissue. It can help clinicians formulate a safer and more effective therapeutic strategy by providing accurate information on prognostic evaluation before the successful surgical intervention of gliomas.

Kinesin Family Member C1 Increases Temozolomide Resistance of Glioblastoma Through Promoting DNA Damage Repair.

Glioblastoma (GBM) is one of the most frequent primary malignant brain tumors with a poor prognosis. Unfortunately, due to the intrinsic or acquired chemoresistance of GBM cells, it easily becomes refractory disease and tumors are easy to recur. Therefore, it is critical to elucidate the molecular mechanisms underlying the chemoresistance of GBM cells to discover more efficient therapeutic treatments. Kinesin family member C1 (KIFC1) is a normal nonessential kinesin motor that affects the progression of multiple types of cancers. However, whether KIFC1 have a function in GBM is still unexplored. Here we found that KIFC1 was upregulated in human temozolomide (TMZ)-resistant GBM tissues. KIFC1 silencing is sufficient to inhibit GBM cell proliferation and amplify TMZ-induced repression of cell proliferation. Mechanistically, KIFC1 silencing contributed to DNA damage, cell cycle arrest, and apoptosis through regulating Rad51, Akt, and DNA-PKcs phosphorylation. We also noticed that KIFC1 silencing also inhibited tumor formation and increased TMZ sensitivity through regulating Ki67, Rad51, γ-H2AX, and phosphorylation of AKT in vivo. Our findings therefore confirm the involvement of KIFC1 in GBM progression and provide a novel understanding of KIFC1-Akt axis in the sensitivity of GBM to chemotherapy.

LINC01152 upregulates MAML2 expression to modulate the progression of glioblastoma multiforme via Notch signaling pathway.

Glioblastoma multiforme (GBM) brings serious physical and psychological pain to GBM patients, whose survival rate remains not optimistic. Long noncoding RNAs (lncRNAs) have been reported to participate in the progression of many cancers, including GBM. However, the mechanism and function of long intergenic non-protein coding RNA 1152 (LINC01152) in GBM are still unclear. In our study, we aimed to explore the function and mechanism of LINC01152 in GBM. Then qRT-PCR analysis was implemented to search the expression of RNAs in GBM tissues and cells. Functional assays such as EdU assay, colony formation assay, TUNEL assay and flow cytometry analysis were conducted to estimate GBM cell proliferation and apoptosis. RNA pull down assay, luciferase reporter assay, RIP and ChIP assays were implemented to search the binding between molecules. As a result, we discovered that LINC01152 was upregulated in GBM tissues and cells. LINC01152 and mastermind like transcriptional coactivator 2 (MAML2) could both play the oncogenic part in GBM. Moreover, LINC01152 positively regulated MAML2 in GBM by sponging miR-466 and recruiting SRSF1. In turn, RBPJ/MAML2 transcription complex was found to activate the transcription of LINC01152 in GBM cells. In conclusion, LINC01152 could upregulate the expression of MAML2 to promote tumorigenesis in GBM via Notch signaling pathway.

NCAPG2 facilitates glioblastoma cells' malignancy and xenograft tumor growth via HBO1 activation by phosphorylation.

NCAPG2 (non-SMC condensin II complex subunit G2), as an important factor in cell mitosis, has been the focus in the study of different cancers. However, the role of NCAPG2 in the malignancy of glioblastoma cells remains unknown. The findings from the present study demonstrated that NCAPG2 was significantly increased in human glioblastoma tissues and was associated with poor clinical outcome. Moreover, NCAPG2 could promote proliferation, migration, and invasion and regulate cell cycle in glioblastoma cells. Investigation of the molecular mechanism indicated that NCAPG2 regulated HBO1 phosphorylation and H4 histone acetylase activation, modulated the activation of Wnt/ß-catenin pathway, and the binding of MCM protein to chromatin to exert its role. Furthermore, knockdown of HBO1 was found to reverse the effect of NCAPG2 overexpression on cell proliferation, migration, invasion, and cell cycle. In addition, knockdown of NCAPG2 attenuated glioblastoma tumorigenesis in vivo. Taken together, the findings demonstrated that NCAPG2 facilitates the malignancy of glioblastoma cells and xenograft tumor growth via HBO1 activation by phosphorylation. These results improve our understanding of the mechanism underlying glioblastoma progression and may contribute to the identification of novel biomarkers and therapeutic targets for glioblastoma.

MYC-activated lncRNA HNF1A-AS1 overexpression facilitates glioma progression via cooperating with miR-32-5p/SOX4 axis.

Mounting literatures have revealed the crucial effects of long noncoding RNA (lncRNA) in various cancers, including glioma. HNF1A-AS1, a novel lncRNA, is reported to modulate tumorigenesis and development of multiple cancers. However, the tumorigenic function of lncRNA HNF1A-AS1 in glioma remains largely unknown. quantitative reverse transcription and polymerase chain reaction and western blot assays were applied to evaluate the expression of relevant mRNAs and proteins. 5-Ethynyl-2'- deoxyuridine, terminal deoxynucleotidyl transferase dUTP nick-end labeling, flow cytometry, and transwell assays were conducted for examining the influence of HNF1A-AS1 on glioma cell functions. The relationship among RNAs was investigated by mechanical experiments. The results demonstrated that HNF1A-AS1 was predominantly highly expressed in glioma cell lines compared with nontumor glial epithelial cell, which was associated with the stimulation of transcription factor myelocytomatosis oncogene. Knockdown of HNF1A-AS1 remarkably inhibited glioma cells proliferation, migration, and invasion, while accelerating cell apoptosis in vitro. Mechanically, HNF1A-AS1 served as a miR-32-5p sponge. Moreover, SOX4 was discovered as a target of miR-32-5p. Inhibited miR-32-5p or upregulated SOX4 could markedly counteract the inhibitory effects of silencing HNF1A-AS1 on glioma malignant biological behaviors. HNF1A-AS1 exerted oncogenic property in glioma progression via upregulating miR-32-5p-mediated SOX4 expression, suggesting potential novel therapeutic target for future glioma treatment.

Suppression of Angiotensin-(1-7) on the Disruption of Blood-Brain Barrier in Rat of Brain Glioma.

Glioblastoma multiforme (GBM) is the most primary brain tumor, specially characterized with the damage of blood-brain barrier (BBB). The Ang-(1-7) was proven to have an inhibitory effect on glioblastoma growth. However, its role on blood-brain barrier (BBB) and the underlying molecular mechanism remains unclear. In this study, Ang-(1-7) significantly relieved the damage of blood-brain barrier in rats with intracranial U87 gliomas as evaluated by magnetic resonance imaging (MRI). Furthermore, its treatment attenuated BBB permeability, tumor growth and edema formation. Similarly, Ang-(1-7) also decreased U87 glioma cells barrier permeability in vitro. Further analysis showed that Ang-(1-7) could effectively restore tight junction protein (claudin-5 and ZO-1) expression levels both in rats and U87 glioma cells by affecting the activation of JNK pathway. SP600125, an inhibitor of JNK, significantly enhanced the expression of Claudin-5 and ZO-1, and decreased the disruption of BBB and enhanced the efficiency of Ang-(1-7) in glioma rats. Taken together, this study demonstrated a protective role of Ang-(1-7) in glioma-induced blood-brain barrier damage by regulating tight junction protein expression. Accordingly, Ang-(1-7) may become a promising therapeutic agent against glioma.

B-cell CLL/lymphoma 3 promotes glioma cell proliferation and inhibits apoptosis through the oncogenic STAT3 pathway.

Aberrant expression of oncogenes and/or tumor suppressors play fundamental roles in the pathogenesis of glioma. B-cell CLL/lymphoma 3 (BCL3) was previously found to be a putative proto-oncogene in human cancers and the decoy receptor DcR1 is induced in a p50/Bcl3-dependent manner and attenuates the efficacy of temozolomide in glioblastoma cells. However, its expression status, clinical significance and biological functions in glioma remain largely unknown. In the present study, the levels of BCL3 were overexpressed in glioma compared to normal brain tissues. Furthermore, high expression of BCL3 protein was confirmed by immunoblotting in glioma cells as compared with normal human astrocyte cell line. The positive expression of BCL3 was correlated with adverse prognostic features and reduced overall survival rate of glioma patients. BCL3 silencing resulted in prominent decreased proliferation, cell cycle arrest in G1 phase and increased apoptosis in U251 cells. In contrast, BCL3 overexpression in U87 cells remarkably facilitated proliferative ability and cell cycle progression and induced apoptosis. In vivo studies showed that BCL3 knockdown inhibited the tumor growth of U251 cells in a mouse xenograft model. Mechanistically, BCL3 positively regulated the abundance of STAT3, p-STAT3 and the downstream targets of STAT3 pathway including BCL2, MCL-1 and cyclin D1 in glioma cells. Furthermore, a positive correlation between BCL3 and STAT3 expression was observed in glioma specimens. Notably, we confirmed that STAT3 knockdown abolished the oncogenic roles of BCL3 in glioma. In conclusion, we suggest that BCL3 serves as an oncogene in glioma by modulating proliferation, cell cycle progression and apoptosis, and its oncogenic effects are mediated by the STAT3 signaling pathway.

ATPase inhibitory factor 1 is a potential prognostic marker for the migration and invasion of glioma.

Adenosine triphosphatase inhibitory factor 1 (IF1) has previously been considered to be a driving oncogene in human cancers. Several studies have revealed that IF1 overexpression is present in a variety of tumor types and promotes tumor growth and metastasis. The present study aimed to investigate the clinical significance of IF1 in glioma and the role of IF1 in cell migration and invasion. The mRNA and protein expression of IF1 in glioma tissues was found to be significantly increased compared with the expression in normal brain tissues (P<0.05). The presence of IF1 expression was significantly associated with an advanced clinical stage in glioma (P<0.05). Furthermore, the presence of IF1 expression was found to be associated with a reduced overall survival rate of glioma patients (P<0.05). Multivariate Cox regression analysis indicated that IF1 was an independent factor for predicting the overall survival rate of patients with glioma (P<0.05). IF1 knockdown also significantly reduced the number of migratory and invasive U251 and U87 cells (P<0.05). In addition, IF1 knockdown inhibited the expression of nuclear factor-κB (NF-κB) and Snai1, and led to increased E-cadherin expression and reduced vimentin expression. In conclusion, the presence of IF1 expression is associated with poor clinicopathological features in glioma. IF1 expression is an independent prognostic marker for predicting the overall survival rate of patients with glioma. Mechanistically, IF1 may promote glioma cell migration and invasion through the NF-κB/Snai1 axis.