Dexamethasone-mediated oncogenicity in vitro and in an animal model of glioblastoma.

OBJECTIVEDexamethasone, a known regulator of mesenchymal programming in glioblastoma (GBM), is routinely used to manage edema in GBM patients. Dexamethasone also activates the expression of genes, such as CEBPB, in GBM stem cells (GSCs). However, the drug's impact on invasion, proliferation, and angiogenesis in GBM remains unclear. To determine whether dexamethasone induces invasion, proliferation, and angiogenesis in GBM, the authors investigated the drug's impact in vitro, in vivo, and in clinical information derived from The Cancer Genome Atlas (TCGA) cohort.METHODSExpression profiles of patients from the TCGA cohort with mesenchymal GBM (n = 155) were compared with patients with proneural GBM by comparative marker selection. To obtain robust data, GSCs with IDH1 wild-type (GSC3) and with IDH1 mutant (GSC6) status were exposed to dexamethasone in vitro and in vivo and analyzed for invasion (Boyden chamber, human-specific nucleolin), proliferation (Ki-67), and angiogenesis (CD31). Ex vivo tumor cells from dexamethasone-treated and control mice were isolated by fluorescence activated cell sorting and profiled using Affymetrix chips for mRNA (HTA 2.0) and microRNAs (miRNA 4.0). A pathway analysis was performed to identify a dexamethasone-regulated gene signature, and its relationship with overall survival (OS) was assessed using Kaplan-Meier analysis in the entire GBM TCGA cohort (n = 520).RESULTSThe mesenchymal subgroup, when compared with the proneural subgroup, had significant upregulation of a dexamethasone-regulated gene network, as well as canonical pathways of proliferation, invasion, and angiogenesis. Dexamethasone-treated GSC3 demonstrated a significant increase in invasion, both in vitro and in vivo, whereas GSC6 demonstrated a modest increase. Furthermore, dexamethasone treatment of both GSC3 and GSC6 lines resulted in significantly elevated cell proliferation and angiogenesis in vivo. Patients with mesenchymal GBM had significant upregulation of dexamethasone-regulated pathways when compared with patients with proneural GBM. A prognostic (p = 0.0007) 33-gene signature was derived from the ex vivo expression profile analyses and used to dichotomize the entire TCGA cohort by high (median OS 12.65 months) or low (median OS 14.91 months) dexamethasone signature.CONCLUSIONSThe authors present evidence that furthers the understanding of the complex effects of dexamethasone on biological characteristics of GBM. The results suggest that the drug increases invasion, proliferation, and angiogenesis in human GSC-derived orthotopic tumors, potentially worsening GBM patients' prognoses. The authors believe that careful investigation is needed to determine how to minimize these deleterious dexamethasone-associated side effects in GBM.

CD90 Expression Controls Migration and Predicts Dasatinib Response in Glioblastoma.

Purpose: CD90 (Thy-1) is a glycophosphatidylinositol-anchored glycoprotein considered as a surrogate marker for a variety of stem cells, including glioblastoma (GBM) stem cells (GSC). However, the molecular and cellular functions of CD90 remain unclear.Experimental Design: The function of CD90 in GBM was addressed using cellular models from immortalized and primary GBM lines, in vivo orthotopic mouse models, and GBM specimens' transcriptome associated with MRI features from GBM patients. CD90 expression was silenced in U251 and GBM primary cells and complemented in CD90-negative U87 cells.Results: We showed that CD90 is not only expressed on GSCs but also on more differentiated GBM cancer cells. In GBM patients, CD90 expression was associated with an adhesion/migration gene signature and with invasive tumor features. Modulation of CD90 expression in GBM cells dramatically affected their adhesion and migration properties. Moreover, orthotopic xenografts revealed that CD90 expression induced invasive phenotypes in vivo Indeed, CD90 expression led to enhanced SRC and FAK signaling in our GBM cellular models and GBM patients' specimens. Pharmacologic inhibition of these signaling nodes blunted adhesion and migration in CD90-positive cells. Remarkably, dasatinib blunted CD90-dependent GBM cell invasion in vivo and killed CD90high primary GSC lines.Conclusions: Our data demonstrate that CD90 is an actor of GBM invasiveness through SRC-dependent mechanisms and could be used as a predictive factor for dasatinib response in CD90high GBM patients. Clin Cancer Res; 23(23); 7360-74. ©2017 AACR.

Radiographic patterns of progression with associated outcomes after bevacizumab therapy in glioblastoma patients.

Treatment response and survival after bevacizumab failure remains poor in patients with glioblastoma. Several recent publications examining glioblastoma patients treated with bevacizumab have described specific radiographic patterns of disease progression as correlating with outcome. This study aims to scrutinize these previously reported radiographic prognostic models in an independent data set to inspect their reproducibility and potential for clinical utility. Sixty four patients treated at MD Anderson matched predetermined inclusion criteria. Patients were categorized based on previously published data by: (1) Nowosielski et al. into: T2-diffuse, cT1 Flare-up, non-responders and T2 circumscribed groups (2) Modified Pope et al. criteria into: local, diffuse and distant groups and (3) Bahr et al. into groups with or without new diffusion-restricted and/or pre-contrast T1-hyperintense lesions. When classified according to Nowosielski et al. criteria, the cT1 Flare-up group had the longest overall survival (OS) from bevacizumab initiation, with non-responders having the worst outcomes. The T2 diffuse group had the longest progression free survival (PFS) from start of bevacizumab. When classified by modified Pope at al. criteria, most patients did not experience a shift in tumor pattern from the pattern at baseline, while the PFS and OS in patients with local-to-local and local-to-diffuse/distant patterns of progression were similar. Patients developing restricted diffusion on bevacizumab had worse OS. Diffuse patterns of progression in patients treated with bevacizumab are rare and not associated with worse outcomes compared to other radiographic subgroups. Emergence of restricted diffusion during bevacizumab treatment was a radiographic marker of worse OS.

A Dexamethasone-regulated Gene Signature Is Prognostic for Poor Survival in Glioblastoma Patients.

BACKGROUND: Dexamethasone is reported to induce both tumor-suppressive and tumor-promoting effects. The purpose of this study was to identify the genomic impact of dexamethasone in glioblastoma stem cell (GSC) lines and its prognostic value; furthermore, to identify drugs that can counter these side effects of dexamethasone exposure. METHODS: We utilized 3 independent GSC lines with tumorigenic potential for this study. Whole-genome expression profiling and pathway analyses were done with dexamethasone-exposed and control cells. GSCs were also co-exposed to dexamethasone and temozolomide. Risk scores were calculated for most affected genes, and their associations with survival in The Cancer Genome Atlas and Repository of Molecular Brain Neoplasia Data databases. In silico Connectivity Map analysis identified camptothecin as antagonist to dexamethasone-induced negative effects. RESULTS: Pathway analyses predicted an activation of dexamethasone network (z-score: 2.908). Top activated canonical pathways included "role of breast cancer 1 in DNA damage response" (P=1.07E-04). GSCs were protected against temozolomide-induced apoptosis when coincubated with dexamethasone. Altered cellular functions included cell movement, cell survival, and apoptosis with z-scores of 2.815, 5.137, and -3.122, respectively. CCAAT/enhancer binding protein beta (CEBPB) was activated in a dose dependent manner specifically in slow-dividing "stem-like" cells. CEBPB was activated in dexamethasone-treated orthotopic tumors. Patients with high risk scores had significantly shorter survival. Camptothecin was validated as potential partial neutralizer of dexamethasone-induced oncogenic effects. CONCLUSIONS: Dexamethasone exposure induces a genetic program and CEBPB expression in GSCs that adversely affects key cellular functions and response to therapeutics. High risk scores associated with these genes have negative prognostic value in patients. Our findings further suggest camptothecin as a potential neutralizer of adverse dexamethasone-mediated effects.

Multicenter imaging outcomes study of The Cancer Genome Atlas glioblastoma patient cohort: imaging predictors of overall and progression-free survival.

BACKGROUND: Despite an aggressive therapeutic approach, the prognosis for most patients with glioblastoma (GBM) remains poor. The aim of this study was to determine the significance of preoperative MRI variables, both quantitative and qualitative, with regard to overall and progression-free survival in GBM. METHODS: We retrospectively identified 94 untreated GBM patients from the Cancer Imaging Archive who had pretreatment MRI and corresponding patient outcomes and clinical information in The Cancer Genome Atlas. Qualitative imaging assessments were based on the Visually Accessible Rembrandt Images feature-set criteria. Volumetric parameters were obtained of the specific tumor components: contrast enhancement, necrosis, and edema/invasion. Cox regression was used to assess prognostic and survival significance of each image. RESULTS: Univariable Cox regression analysis demonstrated 10 imaging features and 2 clinical variables to be significantly associated with overall survival. Multivariable Cox regression analysis showed that tumor-enhancing volume (P = .03) and eloquent brain involvement (P < .001) were independent prognostic indicators of overall survival. In the multivariable Cox analysis of the volumetric features, the edema/invasion volume of more than 85 000 mm(3) and the proportion of enhancing tumor were significantly correlated with higher mortality (Ps = .004 and .003, respectively). CONCLUSIONS: Preoperative MRI parameters have a significant prognostic role in predicting survival in patients with GBM, thus making them useful for patient stratification and endpoint biomarkers in clinical trials.

Adolescent lipoprotein classifications according to National Health and Nutrition Examination Survey (NHANES) vs. National Cholesterol Education Program (NCEP) for predicting abnormal lipid levels in adulthood in a Middle East population.

BACKGROUND: To compare the predictive ability of adolescent lipoprotein classification using the National Examination Survey (NHANES) cut points and those of the National Cholesterol Education Program (NCEP) for predicting abnormal levels in adulthood. METHOD: From 1032 adolescents, aged 14-19 years, participants of the Tehran Lipid and Glucose Study, all lipid measures were determined at baseline and again after 6 years. Multivariable Odds Ratios (ORs) were calculated for borderline and high categories of lipids to predict dyslipidemia in adulthood, considering the normal level as a reference. Area under the receiving characteristics curve (AUC) was used to assess the predictive ability of each adolescent lipid classification. RESULT: Applying the NCEP classification, the prevalences of high total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), triglycerides and low high density lipoprotein cholesterol (HDL-C) in males were 12.1%, 12.9%, 26.1% and 34.2% respectively; in females the corresponding prevalences were 15.4%, 17.9%, 21.4% and 25.0%, respectively. Using NHANES cut points, the prevalence of high TC, LDL-C and triglycerides were lower, than those defined by NCEP; the ORs of high categories of lipids (defined by NHANES) were higher than ORs based on the NECP classification, except for HDL-C. For all lipid measures, both classifications had similar predictive abilities, except for TC/HDL-C, which had higher predictive power applying the NHANES classification rather than the NCEP one (AUC 71% vs. 68%, respectively). CONCLUSION: No differences were found between NCEP and NHANES classifications for prediction of adult dyslipidemia, except for TC/HDL-C. Because of their simple application, NCEP cut points can be used in clinical settings.

Prediction of cardiovascular events with consideration of general and central obesity measures in diabetic adults: results of the 8.4-year follow-up.

BACKGROUND: Obesity is one of the most important cardiovascular disease (CVD) risk factors among diabetic populations. We evaluated the ability of different anthropometric measures for predicting CVD among type 2 diabetic patients. METHODS: The study consisted of 411 men and 599 women, aged ≥30 years, free of CVD at baseline with a median follow-up of 8.4 years. The adjusted hazard ratios (HRs) for CVD were calculated for a 1 standard deviation change in body mass index (BMI), waist circumference (WC), waist-to-hip ratio (WHR), and waist-to-height ratio (WHtR) using Cox proportional regression analysis. RESULTS: A total of 188 CVD events occurred (men, 90; women, 98). In women, in confounder-adjusted analysis [age, fasting plasma glucose (instead of glycosylated hemoglobin), and positive family history of CVD], WHR was associated with incident CVD [1.32 (1.06-1.65)], followed by WC and WHtR, which were marginally significant (P=0.06 and 0.08, respectively); after adjustment for hypertension and hypercholesterolemia, only WHR predicted CVD significantly. In men, the confounder-adjusted (age, fasting plasma glucose, and aspirin use) HR to predict CVD was significant only for WHR [HR 1.21(1.00-1.48)]. CONCLUSION: This study showed WHR was the most powerful predictor of CVD among anthropometric measures, followed by WHtR, in diabetic population.

Electrocardiography-defined silent CHD and risk of cardiovascular events among diabetic patients in a Middle Eastern population.

BACKGROUND: We assessed the clinical outcomes of symptomatic and asymptomatic coronary heart disease (CHD) with type 2 diabetic patients. DESIGN: Population-based cohort study. METHODS: The study sample consisted of 380 men and 546 women, aged ≥30 years. Silent CHD was defined using Minnesota coding criteria on baseline electrocardiogram (ECG), in the absence of a history of CHD and symptoms of angina. Participants were categorized into four groups: group 1, participants with no CHD symptoms and with normal ECG; group 2, silent CHD; group 3, participants with symptomatic CHD but with normal ECG; group 4, participants with symptomatic CHD and ECG-determined CHD. Cox regression analysis was used to estimate the hazard ratios (HRs) of cardiovascular disease (CVD) and CHD events for these groups, with group 1 as the reference. RESULTS: During median follow up of 9.2 years, we ascertained 226 CVD events (202 CHD). In the multivariable-adjusted model, among men, HRs (95% CI) of CVD events were 2.32 (1.29-4.16), 2.56 (1.47-4.46), and 3.97 (2.24-7.02) for groups 2, 3, and 4, respectively; the corresponding figures among women were 1.19 (0.65-2.18), 1.90 (1.24-2.92), and 1.92 (1.02-3.62) respectively. Similar results were achieved for CHD events. CONCLUSION: In both sexes, symptomatic CHD was an independent predictor of recurrent CVD/CHD, regardless of ECG results. In diabetic men with asymptomatic CHD, ECG could be of prognostic value for incident CVD/CHD. The present study provides evidence-based support only in men for the ADA recommendation of 'further cardiac testing for diabetic patients with an abnormal resting ECG'.

Systolic and diastolic blood pressure, mean arterial pressure and pulse pressure for prediction of cardiovascular events and mortality in a Middle Eastern population.

We compared systolic (SBP) and diastolic blood pressure (DBP), mean arterial pressure (MAP) and pulse pressure (PP) as independent predictors of cardiovascular disease (CVD), total and CVD mortality among an Iranian population. The study conducted among 5991 subjects aged ≥ 30 years without baseline CVD and antihypertensive medication. The mean of two measurements of SBP and DBP, in sitting position, was considered the subject's blood pressure. During a median follow-up of 8.7 years, 346 CVD and 157 deaths, 63 attributed to CVD, occurred. Hazard ratios (HRs) of each outcome were calculated for a one standard deviation (SD) increase in each blood pressure (BP) measures. In multivariate models, all BP measures were associated with increased risk of CVD regardless of age. In those aged < 60 years, SBP, DBP, PP and MAP were associated with total mortality (p < 0.05), but in subjects aged ≥ 60 years, only SBP and PP increased risk of total mortality significantly. In multivariate analyses, a 1SD increase in SBP, PP and MAP were associated with 35%, 31% and 28% increased risk of CVD mortality (p < 0.05). In terms of fitness and discrimination of models, DBP, PP and MAP were not superior to SBP. In conclusion, our findings provided further evidence from a Middle Eastern population, in support of SBP predictability for CVD events and CVD and all-cause mortality compared with other BP measures.

Association of educational status with cardiovascular disease: Teheran Lipid and Glucose Study.

OBJECTIVE: The aim of this study was to evaluate the associations between educational level and cardiovascular disease (CVD) in an older Iranian population. METHODS: To estimate the odds ratio (OR) of educational level in a cross-sectional study, logistic regression analysis was used on 1,788 men and 2,204 women (222 men and 204 women positive based on their CVD status) aged ≥ 45 years. RESULTS: In men, educational levels of college degree and literacy level below diploma were inversely associated with CVD in the multivariate model [0.52 (0.28-0.94), 0.61 (0.40-0.92), respectively], but diploma level did not show any significant association with CVD, neither in the crude model nor in the multivariate model. In women, increase in educational level was inversely associated with risk of CVD in the crude model, but in the multivariate adjusted model, literacy level below diploma decreased risk of CVD by 39%, compared with illiteracy. CONCLUSION: Our findings support those of developed countries that, along with other CVD risk factors, educational status has an inverse association with CVD among a representative Iranian population of older men and women.

Lipid ratios and appropriate cut off values for prediction of diabetes: a cohort of Iranian men and women.

BACKGROUND: Dyslipidemia is a risk factor for incident type 2 diabetes; however, no study has specifically assessed the lipid ratios (i.e. total cholesterol (TC)/high density lipoprotein cholesterol (HDL-C) and triglyceride (TG)/HDL-C) as predictors of diabetes. We aimed to compare the independent association between the different lipid measures with incident diabetes over a median follow up of 6.4 years in Iranian men and women. METHOD: The study population consisted of 5201 non diabetic (men = 2173, women = 3028) subjects, aged > or =20 years. The risk factor adjusted odds ratios (ORs) for diabetes were calculated for every 1 standard deviation (SD) change in TC, log-transformed TG, HDL-C, non-HDL-C, TC/HDL-C and log-transformed TG/HDL-C using multivariate logistic regression analysis. Receiver operator characteristic (ROC) curve analysis was used to define the points of the maximum sum of sensitivity and specificity (MAXss) of each lipid measure as a predictor of diabetes. RESULT: We found 366 (146 men and 220 women) new diabetes cases during follow-up. The risk-factor-adjusted ORs for a 1 SD increase in TG, TC/HDL-C and TG/HDL-C were 1.23, 1.27 and 1.25 in men; the corresponding risks in females were 1.36, 1.14, 1.39 respectively (all p < 0.05, except TC/HDL-C in females which was marginally significant, p = 0.07). A 1 SD increase of HDL-C only in women decreased the risk of diabetes by 25% [0.75(0.64-0.89)]. In both genders, there was no difference in the discriminatory power of different lipid measures to predict incident diabetes in the risk factor adjusted models (ROC approximately 82%). TG cutoff values of 1.98 and 1.66 mmol/l; TG/HDL-C cutoff values of 4.7 and 3.7, in men and women, respectively, TC/HDL-C cutoff value of 5.3 in both genders and HDL-C cutoff value of 1.18 mmol/l in women yielded the MAXss for defining the incidence of diabetes. CONCLUSION: TC/HDL-C and TG/HDL-C showed similar performance for diabetes prediction in men population however; among women TG/HDL-C highlighted higher risk than did TC/HDL-C, although there was no difference in discriminatory power. Importantly, HDL-C had a protective effect for incident diabetes only among women.

Lipid measures for prediction of incident cardiovascular disease in diabetic and non-diabetic adults: results of the 8.6 years follow-up of a population based cohort study.

BACKGROUND: Diabetes is a strong risk factor for cardiovascular disease (CVD).The relative role of various lipid measures in determining CVD risk in diabetic patients is still a subject of debate. We aimed to compare performance of different lipid measures as predictors of CVD using discrimination and fitting characteristics in individuals with and without diabetes mellitus from a Middle East Caucasian population. METHODS: The study population consisted of 1021 diabetic (men = 413, women = 608) and 5310 non-diabetic (men = 2317, women = 2993) subjects, aged > or = 30 years, free of CVD at baseline. The adjusted hazard ratios (HRs) for CVD were calculated for a 1 standard deviation (SD) change in total cholesterol (TC), log-transformed triglyceride (TG), high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), non-HDL-C, TC/HDL-C and log-transformed TG/HDL-C using Cox proportional regression analysis. Incident CVD was ascertained over a median of 8.6 years of follow-up. RESULTS: A total of 189 (men = 91, women = 98) and 263(men = 169, women = 94) CVD events occurred, in diabetic and non-diabetic population, respectively. The risk factor adjusted HRs to predict CVD, except for HDL-C, TG and TG/HDL-C, were significant for all lipid measures in diabetic males and were 1.39, 1.45, 1.36 and 1.16 for TC, LDL-C, non- HDL-C and TC/HDL-C respectively. In diabetic women, using multivariate analysis, only TC/HDL-C had significant risk [adjusted HR1.31(1.10-1.57)].Among non-diabetic men, all lipid measures, except for TG, were independent predictors for CVD however; a 1 SD increase in HDL-C significantly decreased the risk of CVD [adjusted HR 0.83(0.70-0.97)].In non-diabetic women, TC, LDL-C, non-HDL-C and TG were independent predictors.There was no difference in the discriminatory power of different lipid measures to predict incident CVD in the risk factor adjusted models, in either sex of diabetic and non-diabetic population. CONCLUSION: Our data according to important test performance characteristics provided evidence based support for WHO recommendation that along with other CVD risk factors serum TC vs. LDL-C, non-HDL-C and TC/HDL-C is a reasonable lipid measure to predict incident CVD among diabetic men. Importantly, HDL-C did not have a protective effect for incident CVD among diabetic population; given that the HDL-C had a protective effect only among non- diabetic men.