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Purpose: Medulloblastoma in children can be categorized into at least four molecular subgroups, offering the potential for targeted therapeutic approaches to reduce treatment-related morbidities. Little is known about the role of tumor microenvironment in medulloblastoma or its contribution to these molecular subgroups. Tumor microenvironment has been shown to be an important source for therapeutic targets in both adult and pediatric neoplasms. In this study, we investigated the hypothesis that expression of genes related to tumor-associated macrophages (TAM) correlates with the medulloblastoma molecular subgroups and contributes to a diagnostic signature.Methods: Gene-expression profiling using human exon array (n = 168) was analyzed to identify medulloblastoma molecular subgroups and expression of inflammation-related genes. Expression of 45 tumor-related and inflammation-related genes was analyzed in 83 medulloblastoma samples to build a gene signature predictive of molecular subgroups. TAMs in medulloblastomas (n = 54) comprising the four molecular subgroups were assessed by immunohistochemistry (IHC).Results: A 31-gene medulloblastoma subgroup classification score inclusive of TAM-related genes (CD163 and CSF1R) was developed with a misclassification rate of 2%. Tumors in the Sonic Hedgehog (SHH) subgroup had increased expression of inflammation-related genes and significantly higher infiltration of TAMs than tumors in the Group 3 or Group 4 subgroups (P < 0.0001 and P < 0.0001, respectively). IHC data revealed a strong association between location of TAMs and proliferating tumor cells.Conclusions: These data show that SHH tumors have a unique tumor microenvironment among medulloblastoma subgroups. The interactions of TAMs and SHH medulloblastoma cells may contribute to tumor growth revealing TAMs as a potential therapeutic target. Clin Cancer Res; 21(6); 1457–65. ©2014 AACR.

PDF file 92K, Supplemental Fig 5: Expression of PID1 protein in human brain tumors and cell lines

PDF file - 190K, Supplemental Fig 2: Proneural and Neural GBMs have higher PID1 mRNA; higher PID1 mRNA correlates with higher OS in patients with gliomas.

Supplemental Methods and Supplemental Figures 1-9 Supplemental Figure 1. Overview of samples studies and 31-gene signature development Supplemental Figure. 2. Non-negative matrix factorization (NMF) analysis of the combined cohort of medulloblastoma samples (n=168) (A) Cophenetic correlation coefficient based on 2000 clustering runs for 2-10 clusters utilizing genes obtained at varying coefficients of variation; the data demonstrate that the highest cophenetic correlation coefficient was obtained at 4 clusters with 369 genes. (B) NMF consensus heatmap of 4 subgroups using the dataset containing 369 genes with high coefficient of variation. (C) Silhouette plot for identification of outliers. Outliers (n=31) were defined as samples with a silhouette width

PDF file - 159K, Supplemental Fig 1: PID1 mRNA is lower in less favorable medulloblastomas in two additional independent datasets; PID1 mRNA correlates with rf-PFS when analyzing CHLA medulloblastomas by tertiles.

PDF file - 17K, Supplemental Fig 4: PID1 increases the proportion of cells in Sub G0/G1 in CHLA-259 medulloblastoma cells.

Purpose: We present here the first report of PID1 (Phosphotyrosine Interaction Domain containing 1; NYGGF4) in cancer. PID1 was identified in 2006 as a gene that modulates insulin signaling and mitochondrial function in adipocytes and muscle cells.Experimental Design and Results: Using four independent medulloblastoma datasets, we show that mean PID1 mRNA levels were lower in unfavorable medulloblastomas (groups 3 and 4, and anaplastic histology) compared with favorable medulloblastomas (SHH and WNT groups, and desmoplastic/nodular histology) and with fetal cerebellum. In two large independent glioma datasets, PID1 mRNA was lower in glioblastomas (GBM), the most malignant gliomas, compared with other astrocytomas, oligodendrogliomas and nontumor brains. Neural and proneural GBM subtypes had higher PID1 mRNA compared with classical and mesenchymal GBM. Importantly, overall survival and radiation-free progression-free survival were longer in medulloblastoma patients whose tumors had higher PID1 mRNA (univariate and multivariate analyses). Higher PID1 mRNA also correlated with longer overall survival in patients with glioma and GBM. In cell culture, overexpression of PID1 inhibited colony formation in medulloblastoma, atypical teratoid rhabdoid tumor (ATRT), and GBM cell lines. Increasing PID1 also increased cell death and apoptosis, inhibited proliferation, induced mitochondrial depolaization, and decreased serum-mediated phosphorylation of AKT and ERK in medulloblastoma, ATRT, and/or GBM cell lines, whereas siRNA to PID1 diminished mitochondrial depolarization.Conclusions: These data are the first to link PID1 to cancer and suggest that PID1 may have a tumor inhibitory function in these pediatric and adult brain tumors. Clin Cancer Res; 20(4); 827–36. ©2013 AACR.

PDF file - 440K, Supplemental Table 1: Characteristics of the CHLA Medulloblastoma Patients. Supplemental Table 2: Neural and Proneural GBM subgroups have higher PID1 mRNA compared to Classical and Mesenchymal.

Supplemental Tables 1-6 Supplemental Table 1. Patient and tumor characteristics Supplemental Table 2. TLDA design (45 genes) Supplemental Table 3. Information for samples evaluated using HuE Supplemental Table 4. TLDA 31-gene molecular classification of core samples Supplemental Table 5. TLDA 31-gene classification for samples without HuEx data Supplemental Table 6. TLDA 31-gene Confusion Matrix

PDF file - 42K, Supplemental Fig 3: PID1 also inhibits colony formation using two other plasmid expression vectors.