H3K27M-mutant diffuse midline gliomas should be further molecularly stratified: an integrated analysis of 669 patients

Activin receptors in human cancer: Functions, mechanisms, and potential clinical applications

Activins are members of the transforming growth factor-β (TGF-β) superfamily and act as key regulators in various physiological processes, such as follicle and embryonic development, as well as in multiple human diseases, including cancer. They have been established to signal through three type I and two type II serine/threonine kinase receptors, which, upon ligand binding, form a final signal-transducing receptor complex that activates downstream signaling and governs gene expression. Recent research highlighted the dysregulation of the expression or activity of activin receptors in multiple human cancers and their critical involvement in cancer progression. Furthermore, expression levels of activin receptors have been associated with clinicopathological features and patient outcomes across different cancers. However, there is currently a paucity of comprehensive systematic reviews of activin receptors in cancer. Thus, this review aimed to consolidate existing knowledge concerning activin receptors, with a primary emphasis on their signaling cascade and emerging biological functions, regulatory mechanisms, and potential clinical applications in human cancers in order to provide novel perspectives on cancer prognosis and targeted therapy.

Insights from a Multicenter Study on Adult H3 K27M-Mutated Glioma: Surgical Resection's Limited Influence on Overall Survival, ATRX as Molecular Prognosticator

BACKGROUND

H3 K27M-mutated gliomas were first described as a new grade 4 entity in the 2016 WHO classification. Current studies have focused on its typical appearance in children and young adults, increasing the need to better understand the prognostic factors and impact of surgery on adults. Here, we report a multicentric study of this entity in adults.

METHODS

We included molecularly confirmed H3 K27M-mutated glioma cases in patients >18 years diagnosed between 2016 and 2022. Clinical, radiological, and surgical features were analyzed. Univariate and multivariate analyses were performed to identify prognostic factors.

RESULTS

Among 70 patients with a mean age of 36.1 years, the median overall survival (OS) was 13.6 + 14 months. Gross-total resection was achieved in 14.3% of patients, whereas 30% had a subtotal resection and 54.3% a biopsy.Tumors located in telencephalon/diencephalon/myelencephalon were associated with a poorer OS, while a location in the mesencephalon/metencephalon showed a significantly longer OS (8.7 vs. 25.0 months, p=0.007). Preoperative Karnofsky Performance Score (KPS) < 80 showed a reduced OS (4.2 vs. 18 months, p=0.02). Furthermore, ATRX loss, found in 25.7%, was independently associated with an increased OS (31 vs. 8.3 months, p=0.0029). Notably, patients undergoing resection showed no survival benefit over biopsy (12 vs. 11 months, p=0.4006).

CONCLUSION

The present study describes surgical features of H3 K27M-mutated glioma in adulthood in a large multicentric study. Our data reveal that ATRX status, location and KPS significantly impact OS in H3 K27M-mutated glioma. Importantly, our dataset indicates that resection does not offer a survival advantage over biopsy.

H3K27-altered diffuse midline gliomas with MAPK pathway alterations: Prognostic and therapeutic implications

Large-scale sequencing led to the identification of driver molecular alterations such as FGFR1 and BRAF in occasional diffuse midline gliomas (DMGs) H3K27-mutant but their significance has not been completely explored. We evaluated these associations in our institutional cohorts. We searched our archives for H3K2M7-mutant gliomas and analyzed the co-occurring genetic alterations. The demographics, clinical information, and pathology were reviewed. Oncoplots and Kaplan-Meier survival curves were generated with the maftools R package. We identified 81 patients (age range 2-68, median 26), of which 79 (97%) were DMGs, and 2 were glioneuronal tumors. The 2 glioneuronal tumors (1 with BRAF fusion and 1 BRAF-V600E-mutant) were removed from the outcome analysis. Four cases had BRAF V600E mutation, 12 had FGFR1 hotspot mutations, and one each had KRAS and NRAS pathogenic mutations. The most common correlating anatomic location was the brainstem for the BRAF group and thalamus for the FGFR1group. Follow-up ranged from 0 to 78 months, average 20.4 months. The overall survival in FGFR1- and BRAF V600E-mutant DMGs was not statistically improved when compared with those that were wildtype. However, the possibility of targeted therapy argues for comprehensive sequencing of H3K27-altered gliomas.

Differences in survival prognosticators between children and adults with H3K27M-mutant diffuse midline glioma

AIMS

H3K27M-mutant diffuse midline glioma (DMG) is a rare and aggressive central nervous system tumor. The biological behavior, clinicopathological characteristics, and prognostic factors of DMG have not yet been completely uncovered, especially in adult patients. This study aims to investigate the clinicopathological characteristics and identify prognostic factors of H3K27M-mutant DMG in pediatric and adult patients, respectively.

METHODS

A total of 171 patients with H3K27M-mutant DMG were included in the study. The clinicopathological characteristics of the patients were analyzed and stratified based on age. The Cox proportional hazard model was used to determine the independent prognostic factors in pediatric and adult subgroups.

RESULTS

The median overall survival (OS) for the entire cohort was 9.0 months. Significant differences were found in some clinicopathological characteristics between children and adults. The median OS was also significantly different between the pediatric and adult subgroups, with 7.1 months for children and 12.3 months for adults (p < 0.001). In the overall population, the multivariate analysis identified adult patients, single lesion, concurrent chemoradiotherapy/radiotherapy, and intact ATRX expression as independent favorable prognostic factors. In the age-stratified subgroups, the prognostic factors varied between children and adults, with intact ATRX expression and single lesion being independent favorable prognostic factors in adults, while infratentorial localization was significantly associated with worse prognosis in children.

CONCLUSIONS

The differences in clinicopathological features and prognostic factors between pediatric and adult patients with H3K27M-mutant DMG suggest the need for further clinical and molecular stratification based on age.

A novel intronic circular RNA circFGFR1int2 up-regulates FGFR1 by recruiting transcriptional activators P65/FUS and suppressing miR-4687-5p to promote prostate cancer progression

Fibroblast growth factor receptor 1 (FGFR1) is a core component of the FGFs/FGFR pathway that activates multiple signalling pathways, including ERK1/2, PI3K/AKT, PLCγ, and NF-κB. Aberrant expression of FGFR1 due to gene amplification, chromosome rearrangement, point mutation, and epigenetic deregulations, have been reported in various cancers. FGFR1 overexpression has also been reported in prostate cancer (PCa), but the underlining mechanisms are not clear. Here we report a novel circular RNA, circFGFR1int2, derived from intron 2 of FGFR1 gene, which is overexpressed in PCa and associated with tumor progression. Importantly, we show that circFGFR1int2 facilitates FGFR1 transcription by recruiting transcription activators P65/FUS and by interacting with FGFR1 promoter. Moreover, we show that circFGFR1int2 suppresses post-transcriptional inhibitory effects of miR-4687-5p on FGFR1 mRNA. These mechanisms synergistically promote PCa cell growth, migration, and invasion. Overexpression of circFGFR1int2 is significantly correlated with higher tumor grade, Gleason score, and PSA level, and is a significant unfavorable prognosticator for CRPC-free survival (CFS) (RR = 3.277, 95% confidence interval: 1.192-9.009; P = 0.021). These findings unravelled novel mechanisms controlling FGFR1 gene expression by intronic circRNA and its potential clinicopathological utility as a diagnostic or therapeutic target.

A comprehensive genomic study of 390 H3F3A-mutant pediatric and adult diffuse high-grade gliomas, CNS WHO grade 4

Malignant brain tumors, known as H3K27-altered diffuse midline glioma (DMG) and H3G34-mutant diffuse hemispheric glioma (DHG), can affect individuals of all ages and are classified as CNS WHO grade 4. We comprehensively characterized 390 H3F3A-mutant diffuse gliomas (201 females, 189 males) arising in pediatric patients (under 20 years old) and adults (20 years and older) evaluated by the CGP program at Foundation Medicine between 2013 and 2020. We assessed information from pathology reports, histopathology review, and clinical data. The cohort included 304 H3K27M-mutant DMG (156 females, 148 males) and 86 H3G34-mutant DHG (45 females, 41 males). Median patient age was 20 years (1-74 years). The frequency of H3K27M-mutant DMG was similar in both pediatric and adult patients in our cohort-48.6% of the patients were over 20 years old, 31.5% over 30, and 18% over 40 at initial diagnosis. FGFR1 hotspot point mutations (N546K and K656E) were exclusively identified in H3K27M-mutant DMG tumors (64/304, 21%; p = 0.0001); these tend to occur in older patients (median age: 32.5 years) and mainly arose in the diencephalon. H3K27M-mutant DMG had higher rates of mutations in NF1 (31.0 vs 8.1%; p = 0.0001) and PIK3CA/PIK3R1 (27.9% vs 15.1%; p = 0.016) compared to H3G34-mutant DHG. However, H3G34-mutant DHG had higher rates of targetable alterations in cell-cycle pathway genes (CDK4 and CDK6 amplification; CDKN2A/B deletion) (27.0 vs 9.0%). Potentially targetable PDGFRA alterations were identified in ~ 20% of both H3G34-mutant DHG and H3K27M-mutant DMG. Overall, in the present study H3K27M-mutant DMG occurred at similar rates in both adult and patient patients. Through our analysis, we were able to identify molecular features characteristic of DMG and DHG. By identifying the recurrent co-mutations including actionable FGFR1 point mutations found in nearly one-third of H3K27M-mutant DMG in young adults, our findings can inform clinical translational studies, patient diagnosis, and clinical trial design.

OpenPBTA: The Open Pediatric Brain Tumor Atlas

Pediatric brain and spinal cancers are collectively the leading disease-related cause of death in children; thus, we urgently need curative therapeutic strategies for these tumors. To accelerate such discoveries, the Children's Brain Tumor Network (CBTN) and Pacific Pediatric Neuro-Oncology Consortium (PNOC) created a systematic process for tumor biobanking, model generation, and sequencing with immediate access to harmonized data. We leverage these data to establish OpenPBTA, an open collaborative project with over 40 scalable analysis modules that genomically characterize 1,074 pediatric brain tumors. Transcriptomic classification reveals universal TP53 dysregulation in mismatch repair-deficient hypermutant high-grade gliomas and TP53 loss as a significant marker for poor overall survival in ependymomas and H3 K28-mutant diffuse midline gliomas. Already being actively applied to other pediatric cancers and PNOC molecular tumor board decision-making, OpenPBTA is an invaluable resource to the pediatric oncology community.

A validated prognostic nomogram for patients with H3 K27M-mutant diffuse midline glioma

H3 K27M-mutant diffuse midline glioma (H3 K27M-mt DMG) is a rare, highly invasive tumor with a poor prognosis. The prognostic factors of H3 K27M-mt DMG have not been fully identified, and there is no clinical prediction model for it. This study aimed to develop and validate a prognostic model for predicting the probability of survival in patients with H3 K27M-mt DMG. Patients diagnosed with H3 K27M-mt DMG in the West China Hospital from January 2016 to August 2021 were included. Cox proportional hazard regression was used for survival assessment, with adjustment for known prognostic factors. The final model was established using the patient data of our center as the training cohort and data from other centers for external independent verification. One hundred and five patients were ultimately included in the training cohort, and 43 cases from another institution were used as the validation cohort. The factors influencing survival probability in the prediction model included age, preoperative KPS score, radiotherapy and Ki-67 expression level. The adjusted consistency indices of the Cox regression model in internal bootstrap validation at 6, 12, and 18 months were 0.776, 0.766, and 0.764, respectively. The calibration chart showed high consistency between the predicted and observed results. The discrimination in external verification was 0.785, and the calibration curve showed good calibration ability. We identified the risk factors that affect the prognosis of H3 K27M-mt DMG patients and then established and validated a diagnostic model for predicting the survival probability of these patients.

Glucosylceramide Synthase Inhibitors Induce Ceramide Accumulation and Sensitize H3K27 Mutant Diffuse Midline Glioma to Irradiation

H3K27M mutant (mut) diffuse midline glioma (DMG) is a lethal cancer with no effective cure. The glycosphingolipids (GSL) metabolism is altered in these tumors and could be exploited to develop new therapies. We tested the effect of the glucosylceramide synthase inhibitors (GSI) miglustat and eliglustat on cell proliferation, alone or in combination with temozolomide or ionizing radiation. Miglustat was included in the therapy protocol of two pediatric patients. The effect of H3.3K27 trimethylation on GSL composition was analyzed in ependymoma. GSI reduced the expression of the ganglioside GD2 in a concentration and time-dependent manner and increased the expression of ceramide, ceramide 1-phosphate, sphingosine, and sphingomyelin but not of sphingosine 1-phosphate. Miglustat significantly increased the efficacy of irradiation. Treatment with miglustat according to dose recommendations for patients with Niemann-Pick disease was well tolerated with manageable toxicities. One patient showed a mixed response. In ependymoma, a high concentration of GD2 was found only in the presence of the loss of H3.3K27 trimethylation. In conclusion, treatment with miglustat and, in general, targeting GSL metabolism may offer a new therapeutic opportunity and can be administered in close proximity to radiation therapy. Alterations in H3K27 could be useful to identify patients with a deregulated GSL metabolism.

Radiotherapy and radio-sensitization in H3K27M -mutated diffuse midline gliomas

BACKGROUND

H3^K27M mutated diffuse midline gliomas (DMGs) are extremely aggressive and the leading cause of cancer-related deaths in pediatric brain tumors with 5-year survival <1%. Radiotherapy is the only established adjuvant treatment of H3^K27M DMGs; however, the radio-resistance is commonly observed.

METHODS

We summarized current understandings of the molecular responses of H3^K27M DMGs to radiotherapy and provide crucial insights into current advances in radiosensitivity enhancement.

RESULTS

Ionizing radiation (IR) can mainly inhibit tumor cell growth by inducing DNA damage regulated by the cell cycle checkpoints and DNA damage repair (DDR) system. In H3K27M DMGs, the aberrant genetic and epigenetic changes, stemness genotype, and epithelial-mesenchymal transition (EMT) disrupt the cell cycle checkpoints and DDR system by altering the associated regulatory signaling pathways, which leads to the development of radio-resistance.

CONCLUSIONS

The advances in mechanisms of radio-resistance in H3^K27M  DMGs promote the potential targets to enhance the sensitivity to radiotherapy.

Clinical Features and Prognosis of Diffuse Midline Glioma: A Series of 24 Cases

BACKGROUND

Diffuse midline glioma (DMG) which occurs in midline structures and characterized by harboring K27M mutation in genes encoding the histone 3 protein is classified as World Health Organization (WHO) grade IV regardless of histological findings and has a poor prognosis. Nevertheless, because of its relatively rare incidence compared with other high-grade gliomas, a comprehensive description encompassing clinical features and genomic profiles of DMG is still lacking.

METHODS

In this study, we analyzed data of 24 patients who were diagnosed as DMG which was confirmed by surgical specimens in both pediatric and adult patients. We described the clinical outcomes of patients with DMG and their genomic profiles through a retrospective analysis of 24 patients with DMG.

RESULTS

The clinical characteristics of the 24 patients with DMG were analyzed. Ten patients (41%) underwent tumor resection and 14 patients (59%) underwent tumor biopsy. The median overall survival was 10.4 months (95% confidence interval [CI], 8.4 to 12.5) and progression free survival was 3.9 months (95% CI, 2.6 to 5.2). Fifteen patients (62%) were accompanied by hydrocephalus. None of the patient, tumor, or treatment factors had any significant associated with survival. In both immunohistochemistry staining (n=24) and targeted next generation sequencing (n=15), TP53 mutation was the most common genetic mutation (25% and 46%, respectively) found in the patients except alterations in histone 3 protein.

CONCLUSION

Although surgical treatment of patient with DMG does not affect the overall survival prognosis, it can help improve the patient's accompanying neurological symptoms in some limited cases. Hydrocephalus is often accompanied with DMG and treatment for hydrocephalus is often also required. Multidisciplinary therapeutic approach is needed.

A systematic review of the clinicopathological features and prognostic outcomes of DICER1-mutant malignant brain neoplasms

OBJECTIVE

DICER1-mutant malignant brain neoplasms are very rare tumors, and published data have relied on case reports or small case series. In this review, the authors aimed to systematically summarize the types and distribution patterns of DICER1 mutations, clinicopathological characteristics, and prognostic outcomes of these tumors.

METHODS

The authors searched PubMed and Web of Science for relevant studies. They included studies if they provided individual patient data of primary malignant brain tumors carrying DICER1 mutations.

RESULTS

The authors found 16 studies consisting of 9 embryonal tumors with multilayered rosettes (ETMRs), 30 pineoblastomas, 52 primary intracranial sarcomas, and 27 pituitary blastomas. Pineoblastoma, ETMR, and pituitary blastoma were more likely to carry DICER1 germline mutations, while only a small subset of primary intracranial sarcomas harbored these mutations (p < 0.001). Nearly 80% of tumors with germline mutations also had another somatic mutation in DICER1. ETMR and primary intracranial sarcoma were associated with an increased risk for tumor progression and relapse compared with pituitary blastoma and pineoblastoma (p = 0.0025), but overall survival (OS) was not significantly different. Gross-total resection (GTR) and radiotherapy administration were associated with prolonged OS.

CONCLUSIONS

ETMR, pineoblastoma, primary intracranial sarcoma, and pituitary blastoma should be considered rare phenotypes of the DICER1 syndrome, and families should be counseled and screened for associated tumors. ETMR and primary intracranial sarcoma had a higher risk of relapse. GTR and radiotherapy appeared to improve the OS of patients with DICER1-mutant malignant intracranial tumors.

Risk stratification of H3 K27M-mutant diffuse midline gliomas based on anatomical locations: an integrated systematic review of individual participant data

OBJECTIVE

The prognostic significance and genetic characteristics of H3 K27M-mutant diffuse midline gliomas (DMGs) in different anatomical locations requires further clarification. In this study, the authors integrated published data to investigate the differences between brainstem, thalamic, and spinal cord tumors.

METHODS

PubMed and Web of Science databases were used to search for eligible articles. Studies were included if they provided individual patient data of H3 K27M-mutant DMGs with available tumor locations. Hazard ratios (HRs) and 95% confidence intervals (CIs) were computed to investigate the survival of each subgroup.

RESULTS

Eight hundred four tumors were identified, including 467, 228, and 109 in the brainstem, thalamus, and spine, respectively. Brainstem tumors were primarily observed in young children, while patients with thalamic and spinal cord tumors afflicted older patients. The Ki-67 labeling index was highest in brainstem tumors. Compared to patients with brainstem tumors, those with thalamic (HR 0.573, 95% CI 0.463-0.709; p < 0.001) and spinal cord lesions (HR 0.460, 95% CI 0.341-0.621; p < 0.001) had a significantly better survival. When patients were stratified by age groups, superior overall survival (OS) of thalamic tumors was observed in comparison to brainstem tumors in young children and adolescents, whereas adult tumors had uniform OS regardless of anatomical sites. Genetically, mutations in HIST1H3B/C (H3.1) and ACVR1 genes were mostly detected in brainstem tumors, whereas spinal cord tumors were characterized by a higher incidence of mutations in the TERT promoter.

CONCLUSIONS

This study demonstrated that H3 K27M-mutant DMGs have distinct clinical characteristics, prognoses, and molecular profiles in different anatomical locations.

The prognostic significance of HIST1H3B/C and H3F3A K27M mutations in diffuse midline gliomas is influenced by patient age

INTRODUCTION

Diffuse midline gliomas (DMGs) are infiltrative midline gliomas harboring H3K27M mutations and are generally associated with poor outcomes. H3K27M mutations include mutations in HIST1H3B/C (H3.1), HIST2H3B/D (H3.2), or H3F3A (H3.3) genes. It is still unclear whether these mutations each portend a universally poor prognosis, or if there are any factors which modulate outcome. The main objective of this study was to study overall survival (OS) of H3.1 versus H3.3 K27M-mutant DMGs in pediatric and adult patients.

METHODS

PubMed and Web of Science were searched, and we included studies if they have individual patient data of DMGs with available H3K27M genotype. Kaplan-Meier analysis and Cox regression models were used to analyze the survival of H3.1 and H3.3 mutations in each subgroup.

RESULTS

We included 26 studies with 102 and 529 H3.1 and H3.3-mutant DMGs, respectively. The H3.1 mutation was more commonly seen in younger age. In pediatric population, H3.3 mutation conferred a shorter survival (median OS of 10.1 vs 14.2 months; p < 0.001) in comparison to H3.1-positive patients, which was further confirmed in the multivariate Cox analysis. Conversely, H3.3 was associated with a prolonged survival in adult patients as compared with H3.1 mutation (median OS of 14.4 vs 1.7 months; p = 0.019).

CONCLUSION

We demonstrated that the prognosis of H3.1 and H3.3 K27M mutation in DMG patients is modulated by patient age. Routine H3K27M mutation genotyping in newly diagnosed DMGs may further stratify patients with these difficult tumors.

The prognostic significance of further genotyping H3G34 diffuse hemispheric gliomas

BACKGROUND

H3G34-mutant diffuse hemispheric glioma (DHG) is recognized as a new, distinct entity in the latest World Health Organization classification for central nervous system tumors and is associated with a particularly aggressive course. The authors performed a systematic review and pooled analysis to investigate the frequency of genetic events in these tumors and to determine whether these events were associated with survival trends.

METHODS

Two electronic databases were accessed to search for relevant data. Included criteria were studies that had individual patient data on H3.3 G34-mutant gliomas. To analyze the impact of genetic events on overall survival, Kaplan-Meier analysis and Cox regression models were used, and corresponding hazard ratios and 95% confidence intervals were computed.

RESULTS

In total, 20 studies with 257 H3G34-mutant DHGs were included for integrated analyses. The H3 glycine-to-valine (H3G34V) mutation showed a significantly worse prognosis than the glycine-to-arginine (H3G34R) mutation (median overall survival, 9.9 vs 14.8 months; hazard ratio, 3.040; 95% confidence interval, 1.208-7.651; P = .018), and this result remained statistically significant in the multivariate Cox regression model. Among H3G34 DHGs, TP53 mutation was the most common genetic alteration (94.9%), followed by ATRX alterations (87.5%), MGMT methylation (79.5%), and PDGFRA alterations (33.2%). The presence of PDGFRA amplification or EGFR amplification conferred poor survival. After adjusting for age and sex, these alterations were still independent indicators for adverse outcomes.

CONCLUSIONS

The authors highlight the important role of molecular stratification of H3G34 DHGs, which may help refine our understanding of the natural history of this group of malignant tumors.