Abstract
Background
Gliomas are the most common primary malignant brain tumor. Diffuse low-grade and intermediate-grade gliomas, which together compose the lower-grade gliomas (LGGs; World Health ...Organization WHO grades II and III), present a therapeutic challenge to physicians due to the heterogeneity of their clinical behavior. Nomograms are useful tools for individualized estimation of survival. This study aimed to develop and independently validate a survival nomogram for patients with newly diagnosed LGG.
Methods
Data were obtained for newly diagnosed LGG patients from The Cancer Genome Atlas (TCGA) and the Ohio Brain Tumor Study (OBTS) with the following variables: tumor grade (II or III), age at diagnosis, sex, Karnofsky performance status (KPS), and molecular subtype (IDH mutant with 1p/19q codeletion IDHmut-codel, IDH mutant without 1p/19q codeletion, and IDH wild-type). Survival was assessed using Cox proportional hazards regression, random survival forests, and recursive partitioning analysis, with adjustment for known prognostic factors. The models were developed using TCGA data and independently validated using the OBTS data. Models were internally validated using 10-fold cross-validation and externally validated with calibration curves.
Results
A final nomogram was validated for newly diagnosed LGG. Factors that increased the probability of survival included grade II tumor, younger age at diagnosis, having a high KPS, and the IDHmut-codel molecular subtype.
Conclusions
A nomogram that calculates individualized survival probabilities for patients with newly diagnosed LGG could be useful to health care providers for counseling patients regarding treatment decisions and optimizing therapeutic approaches. Free online software for implementing this nomogram is provided: https://hgittleman.shinyapps.io/LGG_Nomogram_H_Gittleman/.
Key Points
1. A survival nomogram for lower-grade glioma patients has been developed and externally validated.
2. Free online software for implementing this nomogram is provided allowing for ease of use by practicing health care providers.
Glioblastomas (GBMs) are highly vascular and lethal brain tumors that display cellular hierarchies containing self-renewing tumorigenic glioma stem cells (GSCs). Because GSCs often reside in ...perivascular niches and may undergo mesenchymal differentiation, we interrogated GSC potential to generate vascular pericytes. Here, we show that GSCs give rise to pericytes to support vessel function and tumor growth. In vivo cell lineage tracing with constitutive and lineage-specific fluorescent reporters demonstrated that GSCs generate the majority of vascular pericytes. Selective elimination of GSC-derived pericytes disrupts the neovasculature and potently inhibits tumor growth. Analysis of human GBM specimens showed that most pericytes are derived from neoplastic cells. GSCs are recruited toward endothelial cells via the SDF-1/CXCR4 axis and are induced to become pericytes predominantly by transforming growth factor β. Thus, GSCs contribute to vascular pericytes that may actively remodel perivascular niches. Therapeutic targeting of GSC-derived pericytes may effectively block tumor progression and improve antiangiogenic therapy.
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► Glioblastoma stem cells (GSCs) generate vascular pericytes to maintain tumor vessels ► Targeting GSC-derived pericytes disrupts vessel function and inhibits tumor growth ► GSCs are recruited to the perivascular niche via SDF-1-CXCR4 signaling ► Transforming growth factor β predominantly promotes GSCs to assume a pericyte lineage
In vivo lineage tracing shows that glioblastoma stem cells (GSCs) give rise to vascular pericytes—cells that support vessel function and hence promote tumor growth—and that targeting of GSC-derived pericytes inhibits the growth of these highly vascular and lethal brain tumors.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Malignant gliomas are aggressive brain tumors with limited therapeutic options, and improvements in treatment require a deeper molecular understanding of this disease. As in other cancers, recent ...studies have identified highly tumorigenic subpopulations within malignant gliomas, known generally as cancer stem cells. Here, we demonstrate that glioma stem cells (GSCs) produce nitric oxide via elevated nitric oxide synthase-2 (NOS2) expression. GSCs depend on NOS2 activity for growth and tumorigenicity, distinguishing them from non-GSCs and normal neural progenitors. Gene expression profiling identified many
NOS2-regulated genes, including the cell-cycle inhibitor cell division autoantigen-1 (
CDA1). Further, high
NOS2 expression correlates with decreased survival in human glioma patients, and NOS2 inhibition slows glioma growth in a murine intracranial model. These data provide insight into how GSCs are mechanistically distinct from their less tumorigenic counterparts and suggest that NOS2 inhibition may be an efficacious approach to treating this devastating disease.
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► Glioma stem cell proliferation is supported by nitric oxide synthase-2 (NOS2) ► Nonstem glioma cells and normal neural stem cells are not dependent on NOS2 ► NOS2 affects glioma stem cell gene expression, including cell-cycle inhibitor CDA1 ► Pharmacological inhibition of NOS2 attenuates glioma growth in vivo
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Glioblastoma (GBM) is a prototypical heterogeneous brain tumor refractory to conventional therapy. A small residual population of cells escapes surgery and chemoradiation, resulting in a typically ...fatal tumor recurrence ∼ 7 mo after diagnosis. Understanding the molecular architecture of this residual population is critical for the development of successful therapies. We used whole-genome sequencing and whole-exome sequencing of multiple sectors from primary and paired recurrent GBM tumors to reconstruct the genomic profile of residual, therapy resistant tumor initiating cells. We found that genetic alteration of the p53 pathway is a primary molecular event predictive of a high number of subclonal mutations in glioblastoma. The genomic road leading to recurrence is highly idiosyncratic but can be broadly classified into linear recurrences that share extensive genetic similarity with the primary tumor and can be directly traced to one of its specific sectors, and divergent recurrences that share few genetic alterations with the primary tumor and originate from cells that branched off early during tumorigenesis. Our study provides mechanistic insights into how genetic alterations in primary tumors impact the ensuing evolution of tumor cells and the emergence of subclonal heterogeneity.
Population-based estimates of the incidence of brain metastases are not generally available. The purpose of this study was to calculate population-based incidence proportions (IPs) of brain ...metastases from single primary lung, melanoma, breast, renal, or colorectal cancer.
Patients diagnosed with single primary lung, melanoma, breast, renal, or colorectal cancer (1973 to 2001) in the Metropolitan Detroit Cancer Surveillance System (MDCSS) were used for analysis. IP of brain metastases by primary site and variable of interest (race, sex, age at diagnosis of primary cancer, and Surveillance, Epidemiology, and End Results SEER stage of primary cancer) was calculated with 95% CIs.
Total IP percentage (IP%) of brain metastases was 9.6% for all primary sites combined, and highest for lung (19.9%), followed by melanoma (6.9%), renal (6.5%), breast (5.1%), and colorectal (1.8%) cancers. Racial differences were seen with African Americans demonstrating higher IP% of brain metastases compared with other racial groups for most primary sites. IP% was significantly higher for female patients with lung cancer, and significantly higher for male patients with melanoma. The highest IP% of brain metastases occurred at different ages at diagnoses: age 40 to 49 years for primary lung cancer; age 50 to 59 years for primary melanoma, renal, or colorectal cancers; and age 20 to 39 for primary breast cancer. IP% significantly increased as SEER stage of primary cancer advanced for all primary sites.
Total IP% of brain metastases was lower than previously reported, and it varied by primary site, race, sex, age at diagnosis of primary cancer, and SEER stage of primary cancer.
Glioblastomas display cellular hierarchies containing tumor-propagating glioblastoma stem cells (GSCs). STAT3 is a critical signaling node in GSC maintenance but molecular mechanisms underlying STAT3 ...activation in GSCs are poorly defined. Here we demonstrate that the bone marrow X-linked (BMX) nonreceptor tyrosine kinase activates STAT3 signaling to maintain self-renewal and tumorigenic potential of GSCs. BMX is differentially expressed in GSCs relative to nonstem cancer cells and neural progenitors. BMX knockdown potently inhibited STAT3 activation, expression of GSC transcription factors, and growth of GSC-derived intracranial tumors. Constitutively active STAT3 rescued the effects of BMX downregulation, supporting that BMX signals through STAT3 in GSCs. These data demonstrate that BMX represents a GSC therapeutic target and reinforces the importance of STAT3 signaling in stem-like cancer phenotypes.
► BMX is preferentially expressed in glioblastoma stem cells ► BMX activates STAT3 signaling specifically in glioblastoma stem cells ► BMX controls the expression of key glioblastoma stem cell transcription factors ► Targeting BMX disrupts tumorigenic potential of glioblastoma stem cells
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Magnetic resonance fingerprinting (MRF) allows rapid, simultaneous mapping of T1 and T2 relaxation times and may be an important diagnostic tool to measure tissue characteristics in pediatric brain ...tumors. We examined children and young adults with primary brain tumors to determine whether MRF can discriminate tumor from normal-appearing white matter and distinguish tumor grade.
MRF was performed in 23 patients (14 children and 9 young adults) with brain tumors (19 low-grade glioma, 4 high-grade tumors). T1 and T2 values were recorded in regions of solid tumor (ST), peritumoral white matter (PWM), and contralateral white matter (CWM). Nonparametric tests were used for comparison between groups and regions.
Median scan time for MRF and a sequence for tumor localization was 11 min. MRF-derived T1 and T2 values distinguished ST from CWM (T1: 1,444 ± 254 ms vs. 938 ± 96 ms, p = 0.0002; T2: 61 ± 22 ms vs. 38 ± 9 ms, p = 0.0003) and separated high-grade tumors from low-grade tumors (T1: 1,863 ± 70 ms vs. 1,355 ± 187 ms, p = 0.007; T2: 90 ± 13 ms vs. 56 ± 19 ms, p = 0.013). PWM was distinct from CWM (T1: 1,261 ± 359 ms vs. 933 ± 104 ms, p = 0.0008; T2: 65 ± 51 ms vs. 38 ± 8 ms, p = 0.008), as well as from tumor (T1: 1,261 ± 371 ms vs. 1,462 ± 248 ms, p = 0.047).
MRF is a fast sequence that can rapidly distinguish important tissue components in pediatric brain tumor patients. MRF-derived T1 and T2 distinguished tumor from normal-appearing white matter, differentiated tumor grade, and found abnormalities in peritumoral regions. MRF may be useful for rapid quantitative measurement of tissue characteristics and distinguish tumor grade in children and young adults with brain tumors.
Tumour-associated macrophages (TAMs) are enriched in glioblastoma multiformes (GBMs) that contain glioma stem cells (GSCs) at the apex of their cellular hierarchy. The correlation between TAM density ...and glioma grade suggests a supportive role for TAMs in tumour progression. Here we interrogated the molecular link between GSCs and TAM recruitment in GBMs and demonstrated that GSCs secrete periostin (POSTN) to recruit TAMs. TAM density correlates with POSTN levels in human GBMs. Silencing POSTN in GSCs markedly reduced TAM density, inhibited tumour growth, and increased survival of mice bearing GSC-derived xenografts. We found that TAMs in GBMs are not brain-resident microglia, but mainly monocyte-derived macrophages from peripheral blood. Disrupting POSTN specifically attenuated the tumour-supportive M2 type of TAMs in xenografts. POSTN recruits TAMs through the integrin αvβ₃ as blocking this signalling by an RGD peptide inhibited TAM recruitment. Our findings highlight the possibility of improving GBM treatment by targeting POSTN-mediated TAM recruitment.
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DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SBMB, UILJ, UKNU, UL, UM, UPUK
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