EZH2 Inhibition Sensitizes IDH1R132H-Mutant Gliomas to Histone Deacetylase Inhibitor.

Isocitrate Dehydrogenase-1 (IDH1) is commonly mutated in lower-grade diffuse gliomas. The IDH1R132H mutation is an important diagnostic tool for tumor diagnosis and prognosis; however, its role in glioma development, and its impact on response to therapy, is not fully understood. We developed a murine model of proneural IDH1R132H-mutated glioma that shows elevated production of 2-hydroxyglutarate (2-HG) and increased trimethylation of lysine residue K27 on histone H3 (H3K27me3) compared to IDH1 wild-type tumors. We found that using Tazemetostat to inhibit the methyltransferase for H3K27, Enhancer of Zeste 2 (EZH2), reduced H3K27me3 levels and increased acetylation on H3K27. We also found that, although the histone deacetylase inhibitor (HDACi) Panobinostat was less cytotoxic in IDH1R132H-mutated cells (either isolated from murine glioma or oligodendrocyte progenitor cells infected in vitro with a retrovirus expressing IDH1R132H) compared to IDH1-wild-type cells, combination treatment with Tazemetostat is synergistic in both mutant and wild-type models. These findings indicate a novel therapeutic strategy for IDH1-mutated gliomas that targets the specific epigenetic alteration in these tumors.

Preparation and Characterization of Polypropylene/Sepiolite Nanocomposites for Potential Application in Automotive Lightweight Materials.

Polypropylene (PP)/sepiolite nanocomposites were prepared using the melt blending technique. The effects of nano-sepiolite content on the mechanical property, thermal property, crystallinity, morphology and rheological property of PP/sepiolite nanocomposites were investigated. The organic modified sepiolites (OSep) were dispersed evenly in PP matrix after surface treatment. The addition of OSep improved the storage modulus and thermal stability, showing a strong interaction between OSep and PP matrix. With the increase of OSep content, the fluidity of PP/OSep composites first increased due to the lubrication of surface modifiers and then decreased due to the interaction between OSep and PP. The size of the toughening agent elastomer first increased and then decreased, and the impact notched strength of PP/Osep composites first decreased and then increased. The loading of OSep also reduced the crystallinity and shrinkage rate of PP. PP/OSep nanocomposites have potential applications in high-performance automotive lightweight materials.

Economic Burden Conferred by Population-Level Cancer Screening on Resource-Limited Communities: Lessons From the ESECC Trial.

Objectives: Upper gastrointestinal (G.I.) cancer screening has been conducted in China for decades. However, the economic burden for treatment "intensively" occurred in advance due to screening in resource-limited communities remain unclear. Methods: We compared the treatment costs for upper G.I. cancers from the screening and control arms of a population-based randomized trial in a high-risk area for esophageal cancer (EC) in China based on claims data from the health insurance system in the local area which included whole population coverage. Results: The average out-of-pocket cost per treatment of EC in the screening arm was lower than that in the control arm ($5,972 vs. $7,557). This difference was a consequence of down-staging from screening which resulted in lower cost therapy for earlier stage cancers. Moreover, this result is similar for cardial and non-cardial gastric cancer in the two study arms ($7,933 vs. $10,605). However, three times as many (103 vs. 36) families in the screening arm suffered catastrophic health expenditure for all cancer types. The overall treatment cost for all EC patients in the screening arm ($1,045,119) was 2.44 times that in the control arm ($428,292), and the ratio for cardial and non-cardial gastric cancer was 1.12 ($393,261 vs. $351,557). Conclusion: Cancer treatment secondary to screening may triple the likelihood of catastrophic patient medical expenditure, and sharply increase the economic pressure on the local community, particularly for cancer types which are of high prevalence. Financial support for patients and the health insurance system should be taken into consideration when planning budgets for cancer screening programs in communities which are resource-limited.

Estimating cancer survival and prevalence with the Medical-Insurance-System-based Cancer Surveillance System (MIS-CASS): An empirical study in China.

BACKGROUND: We aimed to establish a new approach for surveillance of cancer prevalence and survival in China, based on the Medical-Insurance-System-based Cancer Surveillance System (MIS-CASS). METHODS: We constructed a standard procedure for data collection, cleaning, processing, linkage, verification, analysis, and estimation of cancer prevalence and survival (including both actual observations and model estimates) by conjoint use of medical insurance claims data and all-cause death surveillance data. As a proof-of-principle study, we evaluated the performance of this surveillance approach by estimating the latest prevalence and survival for upper gastrointestinal cancers in Hua County, a high-risk region for oesophageal cancer in China. FINDINGS: In Hua County, the age-standardised relative 5-year survival was 39·2% (male: 36·8%; female: 43·6%) for oesophageal cancer and 33·3% (male: 29·6%; female: 43·4%) for stomach cancer. For oesophageal cancer, better survival was observed in patients of 45-64 years compared with national average estimates, and women of <75 years had better survival than men. The 5-year prevalence rate in Hua County was 99·8/100,000 (male: 105·9/100,000; female: 93·3/100,000) for oesophageal cancer and 41·5/100,000 (male: 57·4/100,000; female: 24·5/100,000) for stomach cancer. For both of these cancers, the prevalence burden peaked at 65-79 years. The model estimates for survival and prevalence were close to the observations in real investigation, with a relative difference of less than 4·5%. INTERPRETATION: This novel approach allows accurate estimation of cancer prevalence and survival with a short delay, which has great potential for regular use in general Chinese populations, especially those not covered by cancer registries. FUNDING: The National Key R&D Program of China (2016YFC0901404), the National Science & Technology Fundamental Resources Investigation Program of China (2019FY101102), the National Natural Science Foundation of China (82073626), the Taikang Yicai Public Health and Epidemic Control Fund (TKYC-GW-2020), the Beijing-Tianjin-Hebei Basic Research Cooperation Project (J200016), and the Digestive Medical Coordinated Development Center of Beijing Hospitals Authority (XXZ0204).

Estimating cancer incidence based on claims data from medical insurance systems in two areas lacking cancer registries in China.

BACKGROUND: We aimed to establish a Medical-Insurance-System-based Cancer Surveillance System (MIS-CASS) in China and evaluate the completeness and timeliness of this system through reporting cancer incidence rates using claims data in two regions in northern and southern China. METHODS: We extracted claims data from medical insurance systems in Hua County of Henan Province, and Shantou City in Guangdong Province in China from Jan 1, 2012 to Jun 30, 2019. These two regions have been considered to be high risk regions for oesophageal cancer. We developed a rigorous procedure to establish the MIS-CASS, which includes data extraction, cleaning, processing, case ascertainment, privacy protection, etc. Text-based diagnosis in conjunction with ICD-10 codes were used to determine cancer diagnosis. FINDINGS: In 2018, the overall age-standardised (Segi population) incidence rates (ASR World) of cancer in Hua County and Shantou City were 167·39/100,000 and 159·78/100,000 respectively. In both of these areas, lung cancer and breast cancer were the most common cancers in males and females respectively. Hua County is a high-risk region for oesophageal cancer (ASR World: 25·95/100,000), whereas Shantou City is not a high-risk region for oesophageal cancer (ASR World: 11·43/100,000). However, Nanao island had the highest incidence of oesophageal cancer among all districts and counties in Shantou (ASR World: 36·39/100,000). The age-standardised male-to-female ratio for oesophageal cancer was lower in Hua County than in Shantou (1·69 vs. 4·02). A six-month lag time was needed to report these cancer incidences for the MIS-CASS. INTERPRETATION: MIS-CASS efficiently reflects cancer burden in real-time, and has the potential to provide insight for improvement of cancer surveillance in China. FUNDING: The National Key R&D Program of China (2016YFC0901404), the Digestive Medical Coordinated Development Center of Beijing Municipal Administration of Hospitals (XXZ0204), the Sanming Project of Shenzhen (SZSM201612061), and the Shantou Science and Technology Bureau (190829105556145, 180918114960704).

Serum C-peptide concentration and prostate cancer: A meta-analysis of observational studies.

BACKGROUND: The association between serum C-peptide concentration and prostate cancer remains unexplored. Therefore, we conducted a meta-analysis to assess whether C-peptide serum concentrations are associated with increased prostate cancer risk. METHODS: Several databases were searched to identify relevant original research articles published before November 2017. Random-effects models were used to summarize the overall estimate of the multivariable-adjusted odds ratios (ORs) with 95% confidence intervals (CIs). RESULTS: Nine observational studies involving 11,796 participants were identified. The findings of the meta-analysis indicated that the association between serum C-peptide concentration and prostate cancer was not significant (OR: 1.15, 95% CI: 0.85-1.54; for highest versus lowest category C-peptide concentrations, P = .376). The associations were inconsistent, as indicated by subgroup analyses. CONCLUSION: Although our findings provided no support for the hypothesis that serum C-peptide concentration is associated with excess risk of prostate cancer, people must pay attention to this aspect and increase physical activity or modify dietary habits to constrain insulin secretion, which possibly lead to decreased incidence of prostate cancer. Hence, well-designed observational studies involving different ethnic populations are still needed.

Abnormal activation of the sonic hedgehog signaling pathway in endometriosis and its diagnostic potency.

OBJECTIVE: To investigate the abnormal expression of sonic hedgehog (SHH) signaling molecules in 52 eutopic endometrial tissues and its diagnostic potency in endometriosis. DESIGN: Retrospective study. SETTING: University hospital. PATIENT(S): Twenty-six women with histologically confirmed endometriosis and 26 women with histologically normal endometria who were undergoing curettage or hysterectomy were selected. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): The mRNA and protein levels of molecules in the SHH signaling pathway. RESULT(S): The levels of SHH, smoothened, GLI family zinc finger 3, and its downstream signaling transcription factor (GLI1) not only were upregulated in the eutopic endometrium of endometriosis compared with the control endometrium, but also independently predicted the onset and severity of the disease. CONCLUSION(S): This study is the first to reveal differences in the activation of the SHH signaling pathway between women with and without endometriosis and suggests that the SHH signaling pathway has potential in the diagnosis of endometriosis.

Association between cadmium exposure and urolithiasis risk: A systematic review and meta-analysis.

BACKGROUND: We performed a meta-analysis to determine whether a consistent relationship exists between cadmium exposure and urolithiasis in humans. Accordingly, we summarized and reviewed previously published quantitative studies. METHODS: Eligible studies with reference lists published before June 1, 2017 were obtained from searching several databases. Random effects models were used to summary the overall estimate of the multivariate adjusted odds ratios (ORs) with 95% confidence intervals (CIs). RESULTS: Six observational studies involving 88,045 participants were identified and stratified into the following categories according to cadmium assessment results: occupational (n = 4) and dietary (n = 2). The findings of the meta-analysis suggested that the risk of urolithiasis increases significantly by 1.32 times at higher cadmium exposure (OR = 1.32; 95% CI = 1.08-1.62; for highest vs lowest category urinary cadmium values). The summary OR in occupational exposure (OR = 1.56; 95% CI = 1.13-2.14) increased at the same condition. Meanwhile, no association was observed between cadmium exposure and urolithiasis risk in dietary exposure (OR = 1.13; 95% CI = 0.87-1.47). A significant association remained consistent, as indicated by subgroup analyses and sensitivity analyses. CONCLUSIONS: The meta-analysis indicated that increased risk of urolithiasis is associated with high cadmium exposure, and this association is higher in occupational exposure than in dietary exposure. Nevertheless, well-designed observational studies with different ethnic populations are still needed.

Magnetic immunoassay using CdSe/ZnS quantum dots as fluorescent probes to detect the level of DNA methyltransferase 1 in human serum sample.

BACKGROUND: DNA methyltransferase 1 (DNMT1), a dominant enzyme responsible for the transfer of a methyl group from the universal methyl donor to the 5-position of cytosine residues in DNA, is essential for mammalian development and closely related to cancer and a variety of age-related chronic diseases. DNMT1 has become a useful biomarker in early disease diagnosis and a potential therapeutic target in cancer therapy and drug development. However, till now, most of the studies on DNA methyltransferase (MTase) detection have focused on the prokaryote MTase and its activity. METHODS: A magnetic fluorescence-linked immunosorbent assay (FLISA) using CdSe/ZnS quantum dots as fluorescent probes was proposed for the rapid and sensitive detection of the DNMT1 level in this study. Key factors that affect the precision and accuracy of the determination of DNMT1 were optimized. RESULTS: Under the optimal conditions, the limit of detection was 0.1 ng/mL, the linear range was 0.1-1,500 ng/mL, the recovery was 91.67%-106.50%, and the relative standard deviations of intra- and inter-assays were respectively 5.45%-11.29% and 7.03%-11.25%. The cross-reactivity rates with DNA methyltransferases 3a and 3b were only 4.0% and 9.4%, respectively. Furthermore, FLISA was successfully used to detect the levels of DNMT1 in human serum samples, and compared with commercial enzyme-linked immunosorbent assay (ELISA) kits. The results revealed that there was a good correlation between FLISA and commercial ELISA kits (correlation coefficient r=0.866, p=0.001). The linear scope of FLISA was broader than ELISA, and the measurement time was much shorter than ELISA kits. CONCLUSION: These indicated that the proposed FLISA method was sensitive and high throughput and can quickly screen the level of DNMT1 in serum samples.

Relationship between autophagy and perineural invasion, clinicopathological features, and prognosis in pancreatic cancer.

AIM: To investigate the relationship between autophagy and perineural invasion (PNI), clinical features, and prognosis in patients with pancreatic cancer. METHODS: Clinical and pathological data were retrospectively collected from 109 patients with pancreatic ductal adenocarcinoma who underwent radical resection at the First Affiliated Hospital of Zhengzhou University from January 2011 to August 2016. Expression levels of the autophagy-related protein microtubule-associated protein 1A/1B-light chain 3 (LC3) and PNI marker ubiquitin carboxy-terminal hydrolase (UCH) in pancreatic cancer tissues were detected by immunohistochemistry. The correlations among LC3 expression, PNI, and clinical pathological features in pancreatic cancer were analyzed. The patients were followed for further survival analysis. RESULTS: In 109 cases of pancreatic cancer, 68.8% (75/109) had evidence of PNI and 61.5% (67/109) had high LC3 expression. PNI was associated with lymph node metastasis, pancreatitis, and CA19-9 levels (P < 0.05). LC3 expression was related to lymph node metastasis (P < 0.05) and was positively correlated with neural invasion (P < 0.05, r = 0.227). Multivariate logistic regression analysis indicated that LC3 expression, lymph node metastasis, pancreatitis, and CA19-9 level were factors that influenced neural invasion, whereas only neural invasion itself was an independent factor for high LC3 expression. Univariate analysis showed that LC3 expression, neural invasion, and CA19-9 level were related to the overall survival of pancreatic cancer patients (P < 0.05). Multivariate COX regression analysis indicated that PNI and LC3 expression were independent risk factors for poor prognosis in pancreatic cancer (P < 0.05). CONCLUSION: PNI in patients with pancreatic cancer is positively related to autophagy. Neural invasion and LC3 expression are independent risk factors for pancreatic cancer with a poor prognosis.

Association between butchers and cancer mortality and incidence: A systematic review and meta-analysis.

BACKGROUND: In this study, we evaluated whether increased risks of mortality and cancer incidence exist among butchers worldwide. To achieve this goal, we conducted a systematic review and meta-analysis to investigate the correlations of the risks of cancer death and incidence with male and female butchers. METHODS: We obtained data by performing a comprehensive literature search in several databases for eligible studies published before March 2017. Multivariable-adjusted standardized mortality ratios (SMRs) and odds ratio (OR), as well as associated 95% confidence intervals (CIs) and those by subgroups, were extracted and pooled. RESULTS: A total of 17 observational studies comprising 397,726 participants were included in the meta-analysis. The butcher occupation was not associated with all-cancer mortality risk, with pooled overall SMRs of 1.07 (95% CI 0.96-1.20). However, the pooled ORs revealed that butchers hold an elevated risk of total cancer incidence (OR, 1.51; 95% CI, 1.33-1.73). No proof of publication bias was obtained, and the findings were consistent in the subgroup analyses. CONCLUSION: Our results suggest that working as butchers did not significantly influence all-cancer mortality risk but significantly contributed to elevated all-cancer incidence risk. Nevertheless, well-designed observational studies on this topic are necessary to confirm and update our findings.

Quantitative Phosphoproteomics Reveals Wee1 Kinase as a Therapeutic Target in a Model of Proneural Glioblastoma.

Glioblastoma (GBM) is the most common malignant primary brain cancer. With a median survival of about a year, new approaches to treating this disease are necessary. To identify signaling molecules regulating GBM progression in a genetically engineered murine model of proneural GBM, we quantified phosphotyrosine-mediated signaling using mass spectrometry. Oncogenic signals, including phosphorylated ERK MAPK, PI3K, and PDGFR, were found to be increased in the murine tumors relative to brain. Phosphorylation of CDK1 pY15, associated with the G2 arrest checkpoint, was identified as the most differentially phosphorylated site, with a 14-fold increase in phosphorylation in the tumors. To assess the role of this checkpoint as a potential therapeutic target, syngeneic primary cell lines derived from these tumors were treated with MK-1775, an inhibitor of Wee1, the kinase responsible for CDK1 Y15 phosphorylation. MK-1775 treatment led to mitotic catastrophe, as defined by increased DNA damage and cell death by apoptosis. To assess the extensibility of targeting Wee1/CDK1 in GBM, patient-derived xenograft (PDX) cell lines were also treated with MK-1775. Although the response was more heterogeneous, on-target Wee1 inhibition led to decreased CDK1 Y15 phosphorylation and increased DNA damage and apoptosis in each line. These results were also validated in vivo, where single-agent MK-1775 demonstrated an antitumor effect on a flank PDX tumor model, increasing mouse survival by 1.74-fold. This study highlights the ability of unbiased quantitative phosphoproteomics to reveal therapeutic targets in tumor models, and the potential for Wee1 inhibition as a treatment approach in preclinical models of GBM. Mol Cancer Ther; 15(6); 1332-43. ©2016 AACR.

[The role of nuclear factor-κB in endothelial cell inflammatory injury by intermittent hypoxia in rat with emphysema].

OBJECTIVE: To investigate mechanism underlying the role of nuclear factor Kappa B (NF-κB) which induced inflammatory injury and functional lesions of aortic endothelial cells in rat with emphysema and intermittent hypoxia. METHODS: Sixty male Wistar rats were divided randomly into 4 experimental groups (n = 15 each group): control group, emphysema group, intermittent hypoxia (IH) group, emphysema with intermittent hypoxia group. The rats in control group had ad libitum access to food and water under normal circumstance. The rats in the emphysema group were exposed to cigarette smoke twice daily (30 min each time). As for IH group, the rats were exposed to intermittent hypoxia circumstance (8 h/day). Both cigarette smoke twice a day (30 min each time) and intermittent hypoxia circumstance (8 h/day) were imposed on the rats in emphysema with intermittent hypoxia group. All the rats were exposed for 8 weeks. Five rats were randomly selected from each group to measure the blood gas on the ninth week. We collected lung and endothelial tissues of thoracic aorta from the rest sacrificed rats, and observed the pathological changes of lung tissue through HE staining. The levels of ET-1, TNF-α and IL-8 in rat endothelial tissues of thoracic aorta were measured by ELISA testing. Nitrate reductase was used to measure the levels of NO, and RT-PCR to detect the levels of NF-κB mRNA, ICAM-1 mRNA, MMP-9 mRNA and eNOS mRNA. RESULTS: Lung pathology and blood gas results showed that the rat model of emphysema with intermittent hypoxia was established successfully. The levels of ET-1, TNF-α, IL-8 in emphysema with intermittent hypoxia group were (172.4 ± 1.6) ng/L, (104.1 ± 1.4) ng/L, (272.1 ± 3.6) ng/L respectively, significantly higher than the control group, emphysema group and intermittent hypoxia group (all P < 0.05). The level of NO was (27.07 ± 0.57) µmol/L, which was significant reduced; the expression of NF-κB mRNA, ICAM-1 mRNA, MMP-9 mRNA in emphysema with intermittent hypoxia group was significantly upregulated compared with the control goup, emphysema group and intermittent hypoxia group (all P < 0.05). The levels of eNOS mRNA expression were significantly lower than other three groups. The expression of NF-κB mRNA was positively correlated with MMP-9 mRNA level (r = 0.572, P < 0.001) and the expression of NF-κB mRNA was negatively correlated with eNOS mRNA level (r = 0.534, P < 0.001); there was no statistical difference in levels of NF-κB mRNA and eNOS mRNA expression between intermittent hypoxia and emphysema group (P > 0.05). CONCLUSION: Compared with only emphysema or intermittent hypoxia exposure, inflammatory injury of aortic endothelial cells of rats induced by emphysema with intermittent hypoxia was more serious, and may result in more serious cardiovascular complications. The activation of NF-κB pathway may be an important mechanism of its inflammatory response.

Gender differences in the risk factors for endothelial dysfunction in Chinese hypertensive patients: homocysteine is an independent risk factor in females.

OBJECTIVES: Endothelial dysfunction plays a key role in the pathogenesis of cardiovascular disease. However, the gender-related differences in risk factors for endothelial dysfunction are controversial. We investigated the gender differences in the risk factor profiles for endothelial dysfunction in Chinese hypertensive patients. METHODS: Vascular endothelial functions in 213 hypertensive patients were measured by digital reactive hyperemia peripheral arterial tonometry (RH-PAT). Peripheral blood samples were collected, and the self-reported smoking and alcohol consumption status, age, body mass index, heart rate, blood pressure and drug administrations were recorded. RESULTS: RH-PAT indexes were attenuated in both male and female hypertensive patients [1.60 (1.38-2.02) vs. 1.63 (1.44-1.98)]. Multivariate logistic regression analysis identified plasma creatinine (p < 0.001), total cholesterol (p = 0.001), homocysteine (p = 0.002) and smoking (p < 0.001) as the independent factors correlated with gender (male). Multivariate linear regression analysis further identified homocysteine as the factor that is significantly and independently correlated with the decrease in the RH-PAT indexes in female patients (odds ratio: -0.166, 95% confidence interval: -0.292 to -0.040, p = 0.01). However, none of these four factors were correlated with the RH-PAT indexes in male patients. CONCLUSIONS: There are gender-related differences in the risk factors for endothelial dysfunction in Chinese hypertensive patients. Homocysteine is an independent factor for endothelial dysfunction in female hypertensive patients.

Enzymatic conversion from pyridoxal to pyridoxine caused by microorganisms within tobacco phyllosphere.

Vitamin B6 (VB6) comprises six interconvertible pyridine compounds (vitamers), among which pyridoxal 5'-phosphate (PLP) is a coenzyme involved in a high diversity of biochemical reactions. In plants, PLP is de novo synthesized, and pyridoxine (PN) is usually maintained as the predominant B6 vitamer. Although the conversion from pyridoxal (PL) to PN catalyzed by PL reductase in plants has been confirmed, the enzyme itself remains largely unknown. We previously found pre-incubation at 35 °C dramatically enhanced PL reductase activity in tobacco leaf homogenate. In this study, we demonstrated that the increase in the reductase activity was a consequence of phyllosphere microbial proliferation. VB6 was detected from tobacco phyllosphere, and PL level was the highest among three non-phosphorylated B6 vitamers. When the sterile tobacco rich in PL were kept in an open, warm and humid environment to promote microorganism proliferation, a significant change from PL to PN was observed. Our results suggest that there may be a plant-microbe interaction in the conversion from PL to PN within tobacco phyllosphere.

MRI-localized biopsies reveal subtype-specific differences in molecular and cellular composition at the margins of glioblastoma.

Glioblastomas (GBMs) diffusely infiltrate the brain, making complete removal by surgical resection impossible. The mixture of neoplastic and nonneoplastic cells that remain after surgery form the biological context for adjuvant therapeutic intervention and recurrence. We performed RNA-sequencing (RNA-seq) and histological analysis on radiographically guided biopsies taken from different regions of GBM and showed that the tissue contained within the contrast-enhancing (CE) core of tumors have different cellular and molecular compositions compared with tissue from the nonenhancing (NE) margins of tumors. Comparisons with the The Cancer Genome Atlas dataset showed that the samples from CE regions resembled the proneural, classical, or mesenchymal subtypes of GBM, whereas the samples from the NE regions predominantly resembled the neural subtype. Computational deconvolution of the RNA-seq data revealed that contributions from nonneoplastic brain cells significantly influence the expression pattern in the NE samples. Gene ontology analysis showed that the cell type-specific expression patterns were functionally distinct and highly enriched in genes associated with the corresponding cell phenotypes. Comparing the RNA-seq data from the GBM samples to that of nonneoplastic brain revealed that the differentially expressed genes are distributed across multiple cell types. Notably, the patterns of cell type-specific alterations varied between the different GBM subtypes: the NE regions of proneural tumors were enriched in oligodendrocyte progenitor genes, whereas the NE regions of mesenchymal GBM were enriched in astrocytic and microglial genes. These subtype-specific patterns provide new insights into molecular and cellular composition of the infiltrative margins of GBM.

Ribosome profiling reveals a cell-type-specific translational landscape in brain tumors.

Glioma growth is driven by signaling that ultimately regulates protein synthesis. Gliomas are also complex at the cellular level and involve multiple cell types, including transformed and reactive cells in the brain tumor microenvironment. The distinct functions of the various cell types likely lead to different requirements and regulatory paradigms for protein synthesis. Proneural gliomas can arise from transformation of glial progenitors that are driven to proliferate via mitogenic signaling that affects translation. To investigate translational regulation in this system, we developed a RiboTag glioma mouse model that enables cell-type-specific, genome-wide ribosome profiling of tumor tissue. Infecting glial progenitors with Cre-recombinant retrovirus simultaneously activates expression of tagged ribosomes and delivers a tumor-initiating mutation. Remarkably, we find that although genes specific to transformed cells are highly translated, their translation efficiencies are low compared with normal brain. Ribosome positioning reveals sequence-dependent regulation of ribosomal activity in 5'-leaders upstream of annotated start codons, leading to differential translation in glioma compared with normal brain. Additionally, although transformed cells express a proneural signature, untransformed tumor-associated cells, including reactive astrocytes and microglia, express a mesenchymal signature. Finally, we observe the same phenomena in human disease by combining ribosome profiling of human proneural tumor and non-neoplastic brain tissue with computational deconvolution to assess cell-type-specific translational regulation.

Zfx facilitates tumorigenesis caused by activation of the Hedgehog pathway.

The Hedgehog (Hh) signaling pathway regulates normal development and cell proliferation in metazoan organisms, but its aberrant activation can promote tumorigenesis. Hh-induced tumors arise from various tissues and they may be indolent or aggressive, as is the case with skin basal cell carcinoma (BCC) or cerebellar medulloblastoma, respectively. Little is known about common cell-intrinsic factors that control the development of such diverse Hh-dependent tumors. Transcription factor Zfx is required for the self-renewal of hematopoietic and embryonic stem cells, as well as for the propagation of acute myeloid and T-lymphoblastic leukemias. We report here that Zfx facilitates the development of experimental BCC and medulloblastoma in mice initiated by deletion of the Hh inhibitory receptor Ptch1. Simultaneous deletion of Zfx along with Ptch1 prevented BCC formation and delayed medulloblastoma development. In contrast, Zfx was dispensable for tumorigenesis in a mouse model of glioblastoma. We used genome-wide expression and chromatin-binding analysis in a human medulloblastoma cell line to characterize direct, evolutionarily conserved targets of Zfx, identifying Dis3L and Ube2j1 as two targets required for the growth of the human medulloblastoma cells. Our results establish Zfx as a common cell-intrinsic regulator of diverse Hh-induced tumors, with implications for the definition of new therapeutic targets in these malignancies.

Convection-enhanced delivery of etoposide is effective against murine proneural glioblastoma.

BACKGROUND: Glioblastoma subtypes have been defined based on transcriptional profiling, yet personalized care based on molecular classification remains unexploited. Topoisomerase II (TOP2) contributes to the transcriptional signature of the proneural glioma subtype. Thus, we targeted TOP2 pharmacologically with etoposide in proneural glioma models. METHODS: TOP2 gene expression was evaluated in mouse platelet derived growth factor (PDGF)(+)phosphatase and tensin homolog (PTEN)(-/-)p53(-/-) and PDGF(+)PTEN(-/-) proneural gliomas and cell lines, as well as human glioblastoma from The Cancer Genome Atlas. Correlation between TOP2 transcript levels and etoposide susceptibility was investigated in 139 human cancer cell lines from the Cancer Cell Line Encyclopedia public dataset and in mouse proneural glioma cell lines. Convection-enhanced delivery (CED) of etoposide was tested on cell-based PDGF(+)PTEN(-/-)p53(-/-) and retroviral-based PDGF(+)PTEN(-/-) mouse proneural glioma models. RESULTS: TOP2 expression was significantly higher in human proneural glioblastoma and in mouse proneural tumors at early as well as late stages of development compared with normal brain. TOP2B transcript correlated with susceptibility to etoposide in mouse proneural cell lines and in 139 human cancer cell lines from the Cancer Cell Line Encyclopedia. Intracranial etoposide CED treatment (680 µM) was well tolerated by mice and led to a significant survival benefit in the PDGF(+)PTEN(-/-)p53(-/-) glioma model. Moreover, etoposide CED treatment at 80 µM but not 4 µM led to a significant survival advantage in the PDGF(+)PTEN(-/-) glioma model. CONCLUSIONS: TOP2 is highly expressed in proneural gliomas, rendering its pharmacological targeting by intratumoral administration of etoposide by CED effective on murine proneural gliomas. We provide evidence supporting clinical testing of CED of etoposide with a molecular-based patient selection approach.

E2F1 coregulates cell cycle genes and chromatin components during the transition of oligodendrocyte progenitors from proliferation to differentiation.

Cell cycle exit is an obligatory step for the differentiation of oligodendrocyte progenitor cells (OPCs) into myelinating cells. A key regulator of the transition from proliferation to quiescence is the E2F/Rb pathway, whose activity is highly regulated in physiological conditions and deregulated in tumors. In this paper we report a lineage-specific decline of nuclear E2F1 during differentiation of rodent OPC into oligodendrocytes (OLs) in developing white matter tracts and in cultured cells. Using chromatin immunoprecipitation (ChIP) and deep-sequencing in mouse and rat OPCs, we identified cell cycle genes (i.e., Cdc2) and chromatin components (i.e., Hmgn1, Hmgn2), including those modulating DNA methylation (i.e., Uhrf1), as E2F1 targets. Binding of E2F1 to chromatin on the gene targets was validated and their expression assessed in developing white matter tracts and cultured OPCs. Increased expression of E2F1 gene targets was also detected in mouse gliomas (that were induced by retroviral transformation of OPCs) compared with normal brain. Together, these data identify E2F1 as a key transcription factor modulating the expression of chromatin components in OPC during the transition from proliferation to differentiation.