Cross-Modal Training Using Xenium Spatial Transcriptomics Enables DINO-DETR Based Detection of Vascular Niches in H&E Whole-Slide Images

BACKGROUND: Infiltrating WHO grade II and III gliomas are devastating and difficult to treat neoplasms classified as astrocytoma (A2), oligodendroglioma (O2), oligoastrocytoma (OA2), or anaplastic astrocytoma (A3), oligodendroglioma (O3), and oligoastrocytoma (OA3). Anaplastic grade is critically dependent on the presence of mitoses (astrocytomas) or high mitotic activity (oligodendroglial tumors), with CDKN2A deletion considered the most common mechanism for associated cell cycle dysregulation. We therefore sought to determine if p16 loss by immunohistochemistry (IHC) or CDKN2A gene by fluorescence in situ hybridization (FISH) are associated with patient survival across histologic groupings after controlling for age, grade, and other molecular markers. METHODS: Adults (18 years of age) with infiltrating gliomas (grades II or III) were selected from the UCSF Adult Glioma Study (N = 157). The population consisted of 90 males (average age = 43.2) and 67 females (average age = 40.7). Isocitrate dehydrogenase (IDH) status (IDH1 and IDH2) was known for all cases. Histology and grade were as follows: 53 O2, 33 A2, 29 OA2, 20 O3, 15 A3, 7 OA3. CDKN2A FISH was performed using commercial probes and immunostains for p16 and MIB1 (Ki-67) were similarly performed using commercial antibodies. The end point for the analysis was overall survival, analyzed using Cox proportional hazards, stratified by tumor histology and with adjustment for sex, age, grade, and various tumor markers. A total of 61 events (deaths) were observed, and median follow-up time across all subjects was 6.4 years. RESULTS: After controlling for age, sex, and grade, CDKN2A deletion was associated with decreased survival in astrocytoma patients (P = 0.045; HR = 3.1; 95%CI = 1.03-9.2) but not in oligodendroglioma or oligoastrocytoma patients (P = 0.57 and P = 0.67, respectively). A strong inverse association between IDH mutation and CDKN2A deletion was observed in astrocytomas, and the association of CDKN2A deletion with survival was attenuated after controlling for IDH status (P = 0.34). Interestingly, CDKN2A loss was observed in 83% of IDH wild-type versus 33% of IDH-mutant astrocytomas (P = 0.029). CDKN2A loss was only weakly associated with decreased p16 expression (p = 0.09), and the p16 labeling index (LI) was not associated with outcome. There was also no clear association between CDKN2A deletion and MIB1 LI (P = 0.92). CONCLUSIONS: CDKN2A deletion by FISH is associated with shortened survival in astrocytoma patients, but not in patients with oligodendroglial tumors. The strong inverse association between IDH mutation and CDKN2A deletion suggests that CDKN2A status may have prognostic value in the clinical work-up of grade II and III astrocytoma patients. SECONDARY CATEGORY: n/a.

Pancreatic Cancer Ductal Adenocarcinoma (PDAC) is one of the deadliest cancers with 5-year survival of 11%. Understanding the intratumor heterogeneity is a pivotal piece to unravel the complexity of PDAC. While single cell RNASeq identifies the heterogeneous cell populations within the tumor tissue, spatially characterizing the transcriptomic profile of neoplastic and pre-neoplastic populations within the tissue remains a challenge, as the spatial dimension is usually lost upon tissue dissociation. We identified an approach to integrate spatial transcriptomics data with single cell RNASeq data. To characterize the cell populations within the tissue we performed single cell RNASeq on disease pathology-free pancreas tissue and primary PDAC samples. We profiled the transcriptomic profile of Acinar, Ductal, Acinar-to-Ductal (ADM), and Pancreatic Intraepithelial Neoplasia (PanINs) regions of interest (ROIs) across the tissue using the Nanostring GeoMx platform. Differential gene expression analysis using linear mixed-effect models of the cell-type specific ROIs defined pan-marker gene sets for each cell type, which were mapped to UMAP projections of single cell RNA sequencing data using AUCell scoring. As expected, the acinar pan-markers gene set derived from the spatial transcriptomics mapped to the manually annotated acinar population in the single cell data. On the other hand, Ductal, ADM, and PanIN pan-marker gene sets were mapped to distinct clusters that previously were not well-defined by single cell sequencing. The analysis coupled with orthogonal validation using RNAScope revealed gene signatures uniquely specific to ADM lesions and PanINs, respectively. Interestingly, our list included known markers as well as novel findings, supporting the validity of the findings. Furthermore, RNA velocity analysis using scVelo revealed a trajectory of cell evolution originating from acinar cells passing through the newly-defined ADM population and ending towards the ductal population derived from tumor samples. Overall, this integration approach of spatial and single cell transcriptomics can further define the characteristics that differentiate neoplastic and pre-neoplastic populations, as well as the potential drivers for tumorigenesis that could be therapeutically targeted. Citation Format: Ahmed M. Elhossiny, Eileen Carpenter, Padma Kadiyala, Yaqing Zhang, Filip Bednar, Arvind Rao, Timothy Frankel, Marina Pasca Di Magliano. Integrating single cell and spatial transcriptomics define gene signature for pancreatic ductal adenocarcinoma pre-neoplastic lesion [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer; 2022 Sep 13-16; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2022;82(22 Suppl):Abstract nr A006.

2058 Background: Prognosis for mutant isocitrate dehydrogenase (mIDH) gliomas is influenced by tumor type, size, neurologic deficits, and age. Traditionally, patients over 45 are considered high-risk, prompting consideration of early chemoradiation. Recent promising results with the mIDH inhibitor vorasidenib challenge traditional age-based risk stratification, sparking debate over its role in treatment decisions. We evaluated survival relative to age and molecular data obtained from next-generation sequencing (NGS). Methods: Tumor specimens from 598 mIDH gliomas were analyzed using NGS and WTS at Caris Life Sciences (Phoenix, AZ). Samples were stratified by age at diagnosis into four groups: 12-26y, 27-40y, 41-60y, and > 60y. Real-world overall survival (calculated from initial diagnosis to last contact) was obtained from insurance claims data and analyzed using Kaplan-Meier and Cox proportional hazards models. Covariates in the multivariate regression analysis included radiation treatment, temozolomide treatment, and mutation status of different biomarkers. Results: In mIDH astrocytoma group, age distribution was 12-26y, n = 74 (12.4%); 27-40y, n = 271 (45.3%); 41-60y, n = 205 (34.3%); and > 60y, n = 48 (8.0%). In mIDH oligodendroglioma group, age distribution was 12-26y, n = 18 (5.5%); 27-40y, n = 76 (23.2%); 41-60y, n = 137 (41.8%); and > 60y, n = 57 (17.4%). For each subtype, comparisons in survival were made between patients 27-40y vs. 41-60y given larger sample size, and patients with temozolomide treatment before biopsy were excluded (about 10%). Univariate analysis showed that 27-40y patients had shorter survival in astrocytoma (HR = 1.63, 95% CI: 1.07 – 2.50, p = 0.022). However, after adjusting for confounding factors in multivariate analysis, age was not associated with survival. In contrast, TP53 (HR = 4.0, 95% CI: 1.43-11.24, p = 0.008 – mutation rate = 95.4%) and TERT-promoter (HR = 10.36, 95% CI: 4.05-26.45, p < 0.0001 – mutation rate = 9.0%) mutations were independently associated with poorer survival in astrocytoma patients. Univariate analysis showed that age was not associated with survival in oligodendroglioma (HR = 1.07, 95% CI: 0.79-3.65, p = 0.168). KRAS mutations were independently associated with poorer survival in oligodendroglioma patients (HR = 4.36, 95% CI: 1.12-16.92, p = 0.033 - mutation rate = 3%). Conclusions: In this enriched dataset of mIDH low grade glioma patients, which included NGS, age did not contribute to survival differences when comparing patients between 27-40 years with those aged 41-60 years. Rather, selected genetic alterations such as KRAS for oligodendroglioma and TP53 and TERT mutations for astrocytoma were associated with poorer survival. The results suggest that NGS, rather than age, may drive prognosis for mIDH glioma patients.

Malignant diffuse gliomas (MG) of the brain (WHO grade 3-4) are highly aggressive primary tumors of central nervous system (CNS), spreading rapidly by infiltrating healthy brain tissue. In the majority of cases, tumor relapse occurs. The prognostic significance of pre-surgery factors, such as inflammatory markers, particularly, the peripheral blood counts in patients with MG is discussed and remains controversial. The aim of this study was to assess the relationship between the blood cell ratios and overall survival (OS) and relapse-free survival (RFS) in MG patients. The data on 59 MG patients were analyzed: 41 cases of primary (newly diagnosed) MG (astrocytoma (A-III, WHO grade 3, n = 8) and glioblastoma (GB, WHO grade 4, n = 33)) and 18 cases of recurrent MG (recurrent A-III (WHO grade 3, n = 7) and recurrent GB (WHO grade 4, n = 11)). Blood cell counts (peripheral blood leukocytes (PBL), platelets (Pt), neutrophils (Neu), lymphocytes (Ly), monocytes (Mo)) and NLR (Neu/Ly ratio), PLR (Pt/Ly ratio), MLR (Mo/Ly ratio), and systemic immune-inflammation index (SII)) in the preoperative period (prior to re-resection in cases of recurrent MG) were evaluated. The Kaplan - Meier and Cox regression analyses of OS/RFS were performed. The potential association between the blood counts and ratios PLR (≤146 vs. >146), NLR (≤4 vs. >4), MLR (≤0.27 vs. >0.27), SII (≤906 vs. >906), as well as sex (female vs. male) and age (≤60 vs. >61) with OS and RFS were analyzed. PBL and Neu counts, as well as NLR and SII indices, in patients with primary and recurrent GB in the pre-operative period significantly exceeded the reference values (p < 0.02). PBL, Neu, and SII significantly correlated with tumor grade. In patients with primary A-III and GB, longer OS tended to be associated with high PLR, NLR, MLR, and SII values, while in patients with recurrent GB, longer OS tended to be associated with low values of these ratios. Patients with recurrent A-III and GB showed a significant association between low pre-surgery NLR, SII and better RFS while patients with recurrent GB - significant association between low pre-surgery MLR and better RFS. Significant association between OS and sex of patients with both primary and recurrent GB was shown. The results obtained suggest the possible prognostic significance of PLR, NLR, MLR, and SII values in the treatment outcomes of MG patients.

We propose a method to leverage spatial transcriptomics and bioinformatic analysis to identify sub-clonal loss of heterozygosity that could otherwise be missed by standard bulk sequencing in glioblastoma tumors. Glioblastomas are highly invasive and aggressive brain tumors with a low five-year survival rate of less than 10%. Current treatment strategies are not sufficient for long term disease outcome, and innovative approaches to analyze glioblastoma are imperative for future improved options. Many factors contribute to difficulty of treatment, though one critical consideration is the diffuse nature and known intratumoral heterogeneity of this cancer. It is important to determine LOH heterogeneity, as this genomic alteration is associated with copy number variation and specific classifications of gliomas. Loss of heterozygosity is an irreversible deletion of DNA that is a common alteration in cancer. Application of spatial transcriptomics can increase our understanding of genomic complexity across a tissue, and unsupervised graph clustering can computationally separate spatial regions with similar gene expression patterns. Our method investigates spatial clusters individually at known heterozygous SNP sites to identify evidence for LOH with Bayesian inference and a hidden Markov model. Our analysis centers on the balance of reference (A) and non-reference (B) spatial transcriptomics read counts at SNPs of interest. B allele frequency is the number of reads aligned to the alternative allele divided by the total number of reads counted at the SNP. At a normal two-copy state at a heterozygous site, B allele frequency is ideally 50 percent. LOH can be identified as this value deviates toward 0 or 100, and copy number alterations impact this frequency. Our method utilizes Bayes factor values, or likelihood ratios between two models, using allele counts to provide support for either LOH or a heterozygous event. For our analysis, spatial transcriptomics BAMs are processed with a graph clustering algorithm and split into cluster-specific BAMs. We calculate allele count coverage for each cluster at pre-selected heterozygous SNP positions identified through germline exome sequencing. Bayes factor values are then calculated at each SNP, resulting in evidence for LOH or a heterozygous event. Chromosomal regions are segmented by a hidden Markov approach. Cumulative metrics for each segment are evaluated to determine a “state” label of heterozygous, LOH, or undefined. We tested our method on three WHO grade 4 IDH wild-type EGFRvIII positive fresh frozen glioblastoma tissue samples. Sub-clonal heterogeneity was identified in two samples and confirmed by bulk exome sequencing, bulk RNA sequencing, and analysis of initial clinical reports. Citation Format: Michelle G. Webb, Frances Chow, Carmel McCullough, Bohan Zhang, Kyle Hurth, John Carpten, Gabriel Zada, David W. Craig. Identification of sub-clonal loss of heterozygosity (LOH) in glioblastomas analyzed with spatial transcriptomics [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3124.

The 18-kDa translocator protein (TSPO) is overexpressed in brain tumours and represents an interesting target for glioma imaging. 18F-GE-180, a novel TSPO ligand, has shown improved binding affinity and a high target-to-background contrast in patients with glioblastoma. However, the association of uptake characteristics on TSPO PET using 18F-GE-180 with the histological WHO grade and molecular genetic features so far remains unknown and was evaluated in the current study. Fifty-eight patients with histologically validated glioma at initial diagnosis or recurrence were included. All patients underwent 18F-GE-180 PET, and the maximal and mean tumour-to-background ratios (TBRmax, TBRmean) as well as the PET volume were assessed. On MRI, presence/absence of contrast enhancement was evaluated. Imaging characteristics were correlated with neuropathological parameters (i.e. WHO grade, isocitrate dehydrogenase (IDH) mutation, O-6-methylguanine-DNA methyltransferase (MGMT) promoter methylation and telomerase reverse transcriptase (TERT) promoter mutation). Six of 58 patients presented with WHO grade II, 16/58 grade III and 36/58 grade IV gliomas. An (IDH) mutation was found in 19/58 cases, and 39/58 were classified as IDH-wild type. High 18F-GE-180-uptake was observed in all but 4 cases (being WHO grade II glioma, IDH-mutant). A high association of 18F-GE-180-uptake and WHO grades was seen: WHO grade IV gliomas showed the highest uptake intensity compared with grades III and II gliomas (median TBRmax 5.15 (2.59-8.95) vs. 3.63 (1.85-7.64) vs. 1.63 (1.50-3.43), p < 0.001); this association with WHO grades persisted within the IDH-wild-type and IDH-mutant subgroup analyses (p < 0.05). Uptake intensity was also associated with the IDH mutational status with a trend towards higher 18F-GE-180-uptake in IDH-wild-type gliomas in the overall group (median TBRmax 4.67 (1.56-8.95) vs. 3.60 (1.50-7.64), p = 0.083); however, within each WHO grade, no differences were found (e.g. median TBRmax in WHO grade III glioma 4.05 (1.85-5.39) vs. 3.36 (2.32-7.64), p = 1.000). No association was found between uptake intensity and MGMT or TERT (p > 0.05 each). Uptake characteristics on 18F-GE-180 PET are highly associated with the histological WHO grades, with the highest 18F-GE-180 uptake in WHO grade IV glioblastomas and a PET-positive rate of 100% among the investigated high-grade gliomas. Conversely, all TSPO-negative cases were WHO grade II gliomas. The observed association of 18F-GE-180 uptake and the IDH mutational status seems to be related to the high inter-correlation of the IDH mutational status and the WHO grades.

Growing evidence suggests that the induction of cellular senescence in vascular cells is causally linked to the etiology of cardiovascular diseases. To investigate systematically the heterogeneity of senescent vascular cells in atherosclerosis, we used a high-fat diet and PCSK9 overexpression to induce atherosclerosis in a senescence reporter mouse model (p16-tdTomato+/-) and performed single-cell RNA sequencing on whole aortas. Using the SenMayo and CellAge gene sets, we identified four clusters of vascular smooth muscle cells (VSMCs), fibroblasts and T cells enriched in features of senescence, which were reduced upon treatment with the senolytic agent ABT-737. We then derived a global senescence signature of atherosclerosis including Spp1, Ctsb and Tnfrsf11b mRNAs. We validated the enrichment of these mRNAs in senescence by using spatial transcriptomics in a second mouse model of atherosclerosis and senolysis (Ldlr-/-; p16-3MR), as well as by analyzing in vitro models of human VSMC senescence. Our results uncover a vascular-specific transcriptomic signature of senescence that may be exploited for tracking and treating age-related vascular diseases.

Nearly all literature for predicting tumor grade in astrocytoma and oligodendroglioma pre-dates the molecular classification system. We investigated the association between contrast enhancement, ADC, and rCBV with tumor grade separately for IDH-mutant astrocytomas and molecularly-defined oligodendrogliomas. For this retrospective study, 44 patients with IDH-mutant astrocytomas (WHO grades II, III, or IV) and 39 patients with oligodendrogliomas (IDH-mutant and 1p/19q codeleted) (WHO grade II or III) were enrolled. Two readers independently assessed preoperative MRI for contrast enhancement, ADC, and rCBV. Inter-reader agreement was calculated, and statistical associations between MRI metrics and WHO grade were determined per reader. For IDH-mutant astrocytomas, both readers found a stepwise positive association between contrast enhancement and WHO grade (Reader A: OR 7.79 [1.97, 30.80], p = 0.003; Reader B: OR 6.62 [1.70, 25.82], p = 0.006); both readers found that ADC was negatively associated with WHO grade (Reader A: OR 0.74 [0.61, 0.90], p = 0.002); Reader B: OR 0.80 [0.66, 0.96], p = 0.017), and both readers found that rCBV was positively associated with WHO grade (Reader A: OR 2.33 [1.35, 4.00], p = 0.002; Reader B: OR 2.13 [1.30, 3.57], p = 0.003). For oligodendrogliomas, both readers found a positive association between contrast enhancement and WHO grade (Reader A: OR 15.33 [2.56, 91.95], p = 0.003; Reader B: OR 20.00 [2.19, 182.45], p = 0.008), but neither reader found an association between ADC or rCBV and WHO grade. Contrast enhancement predicts WHO grade for IDH-mutant astrocytomas and oligodendrogliomas. ADC and rCBV predict WHO grade for IDH-mutant astrocytomas, but not for oligodendrogliomas.

Prostate cancer is one of the most prevalent malignancies among men and remains a major clinical challenge due to the complex tumor microenvironment. Understanding gene expression dynamics at both cellular and spatial levels is essential for improving therapeutic strategies. In this study, we performed an integrated multi-omics analysis using single-cell RNA sequencing and spatial transcriptomics. scRNA-seq data from 15 prostate samples, including 8 normal and 7 tumor tissues, were analyzed to characterize distinct cellular populations. Spatial transcriptomic profiling was conducted on three FFPE prostate tissue sections, including adjacent normal tissue, acinar cell carcinoma, and invasive adenocarcinoma, using the standard 10x Genomics Visium FFPE platform (55 µm capture spots). Single-cell analysis revealed heterogeneity among epithelial, stromal, and immune cell populations, highlighting complex signaling networks in which myeloid cells may contribute to tumor progression through immune suppression and epithelial adaptability. Spatial transcriptomic analysis further identified region-specific expression patterns and spatially restricted tumor niches, including the regional establishment of TXNIP and BIRC3 as genes associated with metabolic stress and inflammatory survival pathways. The spatial colocalization of BIRC3 with tumor vasculature in invasive carcinoma tissue suggests a novel interaction. Our discoveries using an integrated single-cell and spatial transcriptomic approach reveal a high-resolution molecular map of prostate cancer with spatial features that may provide further therapeutic investigation.

Diffuse glioma exhibit an immunosuppressive microenvironment, yet glioma subsets driven by RAF-alterations exhibit an increased immune signature. In pleomorphic xanthoastrocytoma (PXA), we identified CXCL14 as an important factor promoting a cytotoxic T cell response. The molecular and spatial relationships within this tumor type, however, are unknown. To address this, we use single nucleus RNA sequencing (snRNAseq), spatial transcriptomics, and spatial molecular imaging to construct a high-resolution molecular landscape of PXA. SnRNAseq was performed on 36,781 cells from 10 tumors, including initial and recurrent pairs, spatial transcriptomes were performed on a total of 91 FOVs comprised of 17 PXAs, and spatial molecular imaging (SMI) of 1,000 RNA probes at subcellular resolution was performed on 48,518 cells from 6 tumors, including two PXA, two pilocytic astrocytoma, and two ganglioglioma. For snRNAseq, neoplastic cells were separated from non-malignant cells based on analysis of inferred copy number alterations. CellChat was used to infer cell-cell communication. For spatial transcriptomics, data from 200-300µm FOVs were normalized and divided into CD3-high versus CD3-low groups. For SMI, cells with fewer than 20 transcripts were eliminated, data were normalized using simple total counts, cells were segmented using the Nanostring pipeline, and semi-supervised clustering was performed. Dual CXCL14 RNAscope and Iba1/CD3 immunostaining confirmed spatial relationships within the tumor. In PXA with high-CD3, differential gene expression analysis demonstrated broad immune-enrichment and identified upregulation of several ligand-receptor pairs. Integrating these data with snRNAseq and cell-cell communication analysis inferred paracrine interactions between tumor cells and T cells. One such factor, CXCL14, was expressed widely by tumor cells but spatial analysis revealed cohesive clusters of CXCL14-high expressing tumor cells. In anaplastic (CNS WHO grade 3) tumors, however, both CXCL14 expression and microglia decreased. These high-resolution molecular analyses of PXA identify dynamic tumor-immune crosstalk regulating the immune microenvironment.

Objective To investigate the clinical effectiveness of magnetic resonance spectroscopy (MRS) combined with sodium fluorescein(FL) in the treatment of high grade gliomas(HGG). Methods From August 2013 to 2015 November,the clinical data of 72 supratentorial HGG(WHO grade Ⅲ-Ⅳ) patients who had received surgical treatment in our hospital were retrospectively studied,among whom 43 cases received MRS combined with intra-perative FL navigation(observation group),and 29 cases only received conventional surgery(control group). Post-operative radiotherapy and chemotherapy were applied for more than 3 months. Routine enhanced MRI were performed 24-48 hours after the operation to investigate the extent of tumor resection. Six months after the operation,the quality of life of patients was evaluated by using the Karnofsky score,and 1-year postoperative survival rate and progression-free survival(PFS) were observed. Results Postoperative MRI showed that the rate of gross total resection(GTR) in observation group was significantly higher than that in control group(72.09%vs.51.72%;χ2=23.88,P=0.001),and the GTR rate of WHO grade Ⅳ tumors was significantly higher than that of WHO grade Ⅲ tumors in observation group(92.86% vs.62.07%;χ2=6.06,P=0.042). The postoperative Karnofsky score in the observation group was significantly higher than that in control group(μ=2.34,P=0.021). The mean time of follow-up was(16.4±2.4) months(8-21 months) and there was no statistical significant difference between observation group and control group in 1-year survival rate(74.07% vs.77.50%;χ2=4.90,P=0.165) and PFS [(13.2±1.2) months vs.(12.7±2.0) months;χ2=7.26,P=0.067]. In observation group,the PFS of WHO grade Ⅳ patients was significantly higher than that in control group [(14.2±0.3) months vs.(10.0±1.1) months;χ2=11.03,P=0.031]. There was also no statistical significant difference between WHO grade Ⅳ tumors in two groups in terms of 1-year survival rate(71.43% vs.72.54%;χ2=5.33,P=0.089),and there was no statistical significant difference between WHO grade Ⅲ tumors in two groups in 1-year survival rate(75.86% vs. 72.22%;χ2=3.78,P=0.250) and in PFS [(13.7±1.4) months vs.(12.4±0.8) months;χ2=4.85,P=0.083]. Conclusions MRS combined with intraoperative FL navigation technology can improve the resection rate and improve survival quality of patients,and there is no evidence that MRS combined with intraoperative FL navigation prolong the overall survival of patients with high-grade gliomas. Different outcome may be found with longer follow-up and increased simple size.

INTRODUCTION: Agonists of the ligand-activated transcription factors PPARγ and PPARα are in routine clinical use for Type 2 diabetes and lipid control. In vitro studies suggest that PPARγ and PPARα exert antiproliferative and anti-invasive effects on gliomas. PPAR may therefore have a role as a diagnostic and prognostic biomarker or drug target in human gliomas. METHODS: 52 brain tumour samples diagnosed 2011-2013 (34 WHO Grade IV, 14 WHO Grade III, 4 WHO Grade II gliomas), banked at the Brain Tumour Bank Southwest UK were analysed for PPARγ and PPARα expression using dot and western blot techniques. mRNA expression was quantified using rt-PCR. The expression of PPARγ and PPARα was compared with survival data and stratified by WHO tumour grade. RESULTS: In our study PPARγ and PPARα protein expression differs with WHO glioma grade. WHO grade III gliomas show a higher expression of both PPARγ and PPARα when compared with WHO grade IV gliomas. CONCLUSIONS: Our results show for the first time that both PPARγ and PPARα protein expression is significantly increased in WHO grade III gliomas compared to WHO grade IV gliomas. PPARγ and PPARα agonists are in current clinical use and future trials stratified by PPARγ and PPARα expression may reveal a patient cohort with optimum clinical response to these agents.

NADPH oxidases and atherosclerosis: unraveling the details

Despite multimodal treatment, patients with astrocytoma still face a poor survival, and identification of valuable prognostic factors is crucial to yield effective individual therapy strategies. The aim of this study was to investigate progranulin (PGRN) expression in astrocytomas and explore its association with tumor grade and overall patient survival by scoring the PGRN immunoreactivity of both tumor cells and blood vessels. About 210 astrocytoma samples with different WHO grades and 14 normal brain tissues were studied by immunohistochemistry for PGRN. Semi-quantitative RT-PCR and Western blot were carried out to confirm its expression in 35 tumor specimens. Serum levels of PGRN in glioblastoma were examined by enzyme immunometric assay. PGRN expression was almost undetectable in the normal brain tissues by immunohistochemistry but increased in both astrocytoma cells and tumor blood vessels with pathological grading. Sera in glioblastoma were significantly higher than in healthy control. In grade II astrocytoma, strong vascular PGRN expression was closely related to tumor recurrence. In glioblastoma, high total PGRN expression, strong vascular PGRN expression, and strong tumor cellular PGRN expression all correlated with decreased patient survival in univariate analysis. However, only total PGRN expression as well as vascular PGRN expression status was independently associated with patient's survival in the multivariate analysis. These results suggest that PGRN, involved in astrocytoma progression, may serve as a prognostic biomarker for glioblastoma.

OBJECTIVE Survival rates and prognostic factors for supratentorial hemispheric ependymomas have not been determined. The authors therefore designed a retrospective study to determine progression-free survival (PFS), overall survival (OS), and prognostic factors for hemispheric ependymomas. METHODS The study population consisted of 8 patients from our institution and 101 patients from the literature with disaggregated survival information (n = 109). Patient age, sex, tumor side, tumor location, extent of resection (EOR), tumor grade, postoperative chemotherapy, radiation, time to recurrence, and survival were recorded. Kaplan-Meier survival analyses and Cox proportional hazard models were completed to determine survival rates and prognostic factors. RESULTS Anaplastic histology/WHO Grade III tumors were identified in 62% of cases and correlated with older age. Three-, 5-, and 10-year PFS rates were 57%, 51%, and 42%, respectively. Three-, 5-, and 10-year OS rates were 77%, 71%, and 58%, respectively. EOR and tumor grade were identified on both Kaplan-Meier log-rank testing and univariate Cox proportional hazard models as prognostic for PFS and OS. Both EOR and tumor grade remained prognostic on multivariate analysis. Subtotal resection (STR) predicted a worse PFS (hazard ratio [HR] 4.764, p = 0.001) and OS (HR 4.216, p = 0.008). Subgroup survival analysis of patients with STR demonstrated a 5- and 10-year OS of 28% and 0%, respectively. WHO Grade III tumors also had worse PFS (HR 10.2, p = 0.004) and OS (HR 9.1, p = 0.035). Patients with WHO Grade III tumors demonstrated 5- and 10-year OS of 61% and 46%, respectively. Postoperative radiation was not prognostic for PFS or OS. CONCLUSIONS A high incidence of anaplastic histology was found in hemispheric ependymomas and was associated with older age. EOR and tumor grade were prognostic factors for PFS and OS on multivariate analysis. STR or WHO Grade III pathology, or both, predicted worse overall prognosis in patients with hemispheric ependymoma.