Individual Patient-Level Meta-Analysis of the Performance of the Decipher Genomic Classifier in High-Risk Men After Prostatectomy to Predict Development of Metastatic Disease.

Purpose To perform the first meta-analysis of the performance of the genomic classifier test, Decipher, in men with prostate cancer postprostatectomy. Methods MEDLINE, EMBASE, and the Decipher genomic resource information database were searched for published reports between 2011 and 2016 of men treated by prostatectomy that assessed the benefit of the Decipher test. Multivariable Cox proportional hazards models fit to individual patient data were performed; meta-analyses were conducted by pooling the study-specific hazard ratios (HRs) using random-effects modeling. Extent of heterogeneity between studies was determined with the I(2) test. Results Five studies (975 total patients, and 855 patients with individual patient-level data) were eligible for analysis, with a median follow-up of 8 years. Of the total cohort, 60.9%, 22.6%, and 16.5% of patients were classified by Decipher as low, intermediate, and high risk, respectively. The 10-year cumulative incidence metastases rates were 5.5%, 15.0%, and 26.7% ( P \u3c .001), respectively, for the three risk classifications. Pooling the study-specific Decipher HRs across the five studies resulted in an HR of 1.52 (95% CI, 1.39 to 1.67; I(2) = 0%) per 0.1 unit. In multivariable analysis of individual patient data, adjusting for clinicopathologic variables, Decipher remained a statistically significant predictor of metastasis (HR, 1.30; 95% CI, 1.14 to 1.47; P \u3c .001) per 0.1 unit. The C-index for 10-year distant metastasis of the clinical model alone was 0.76; this increased to 0.81 with inclusion of Decipher. Conclusion The genomic classifier test, Decipher, can independently improve prognostication of patients postprostatectomy, as well as within nearly all clinicopathologic, demographic, and treatment subgroups. Future study of how to best incorporate genomic testing in clinical decision-making and subsequent treatment recommendations is warranted

Mitochondrial form and function: an investigation of the mechanism and significance of mitochondrial remodelling in rat cortical astrocytes

Elucidations of the mechanisms that regulate mitochondrial morphology have contributed to a greater understanding of mitochondrial function in eukaryotic cells. To date, mitochondrial morphological changes have mostly been attributed to fission and fusion. Mitochondrial fission is a calcium (Ca2+)/calcineurin mediated process that activates the dynamin related mechanoenzyme DRP1 to cleave the mitochondrial membranes. This thesis explores new evidence that elevations in intracellular calcium produces some mitochondrial fission but the change in morphology is predominately caused by mitochondrial “remodelling”. Mitochondrial remodelling results from a structural change (rounding or elongating) in the membrane of a single mitochondrion without fission or fusion. Due to the nature of tools utilized to assess mitochondrial morphology, remodelling has been largely overlooked in the literature. Using real-time live cell fluorescence microscopy I show that remodelling can occur concomitantly with fission and have provided evidence that the mechanism of remodelling is distinct from fission. Throughout these studies, I used mitochondrially targeted yellow fluorescent protein (mt-eYFP), ratiometric ROS-sensitive GFPs, the mitochondrial membrane potential dye TMRM as well as Ca2+ and ATP FRET probes in rat cortical astrocytes to measure mitochondrial morphological and functional changes in real time. In the first objective chapter, I blocked mitochondrial fission using FK506 and Cyclosporine A and showed that Ca2+ induced mitochondrial remodelling was unaffected. In the second objective, I induced fission and remodelling by applying ROS generating agents such as rotenone and Ca2+ and demonstrated that remodelling was blocked using antioxidants but fission was not attenuated, indicating that remodelling is regulated by ROS. In the final objective chapter, I further investigated the mechanism of remodelling as well as the functional significance of remodelling. I provided evidence that inhibition of glycogen synthase kinase 3β (GSK3β), an enzyme previously associated with fission, induced only mitochondrial remodelling. Furthermore, I showed that remodelling protects cells against some staurosporine induced cell death and that the mechanism of protection may occur through reduced Ca2+ uptake into the mitochondrial matrix. Through exploration of the mechanism and function of mitochondrial remodelling this thesis provides a greater understanding of the role of mitochondria in cellular maintenance and survival

The C. elegans CDK8 Mediator module regulates axon guidance decisions in the ventral nerve cord and during dorsal axon navigation

AbstractReceptors expressed on the growth cone of outgrowing axons detect cues required for proper navigation. The pathway choices available to an axon are in part defined by the set of guidance receptors present on the growth cone. Regulated expression of receptors and genes controlling the localization and activity of receptors ensures that axons respond only to guidance cues relevant for reaching their targets. In genetic screens for axon guidance mutants, we isolated an allele of let-19/mdt-13, a component of the Mediator, a large ∼30 subunit protein complex essential for gene transcription by RNA polymerase II. LET-19/MDT-13 is part of the CDK8 module of the Mediator. By testing other Mediator components, we found that all subunits of the CDK8 module as well as some other Mediator components are required for specific axon navigation decisions in a subset of neurons. Expression profiling demonstrated that let-19/mdt-13 regulates the expression of a large number of genes in interneurons. A mutation in the sax-3 gene, encoding a receptor for the repulsive guidance cue SLT-1, suppresses the commissure navigation defects found in cdk-8 mutants. This suggests that the CDK8 module specifically represses the SAX-3/ROBO pathway to ensure proper commissure navigation

Symptomatic benefit of momelotinib in patients with myelofibrosis: results from the SIMPLIFY phase III studies

Abstract Background Myelofibrosis (MF)‐associated constitutional symptoms can severely impact health‐related quality of life. Clinical trials in MF traditionally measure symptom response to treatment as a landmark endpoint of total symptom score (TSS) reduction ≥50% from baseline. However, this dichotomous assessment provides a limited view of clinically relevant symptomatic changes. Herein we evaluated longitudinal change from baseline in TSS over the continuous 24‐week period and individual symptom scores to obtain a more comprehensive understanding of symptom benefits experienced by patients with MF receiving therapy. Methods Longitudinal symptom change was evaluated using mixed‐effect model repeated measure (MMRM) methodology with individual item‐level analyses to complement the interpretation of the landmark symptom results in the completed phase III SIMPLIFY studies of momelotinib in MF. MMRM compared mean change in TSS from baseline with Week 24 using data from all patient visits. Generalized estimating equations were used to estimate item‐level odds ratios using multiple predictive imputations for missing data. Results Momelotinib and ruxolitinib groups reported similar overall symptom improvements, with a TSS difference of <1.5 points between groups for each post‐baseline visit in SIMPLIFY‐1. In SIMPLIFY‐2, the improvement in TSS observed in momelotinib‐treated patients was consistent with that observed in SIMPLIFY‐1, whereas progressive TSS deterioration was observed with control. Item‐level scores were heterogeneous in both studies. A similar and greater proportion of momelotinib‐treated patients were categorized as “improved” or “stable” compared with control in SIMPLIFY‐1 and SIMPLIFY‐2, respectively. Odds ratios for between‐group comparison ranged from 0.75 to 1.21 in SIMPLIFY‐1, demonstrating similarity in likelihood of symptom improvement. In SIMPLIFY‐2, the likelihood of symptom improvement in each item was higher in the momelotinib arm. Conclusions These findings suggest that momelotinib provides clinically relevant symptom benefits in the JAK inhibitor‐naïve and JAK inhibitor‐exposed settings

Individual Patient-Level Meta-Analysis of the Performance of the Decipher Genomic Classifier in High-Risk Men After Prostatectomy to Predict Development of Metastatic Disease

Purpose To perform the first meta-analysis of the performance of the genomic classifier test, Decipher, in men with prostate cancer postprostatectomy. Methods MEDLINE, EMBASE, and the Decipher genomic resource information database were searched for published reports between 2011 and 2016 of men treated by prostatectomy that assessed the benefit of the Decipher test. Multivariable Cox proportional hazards models fit to individual patient data were performed; meta-analyses were conducted by pooling the study-specific hazard ratios (HRs) using random-effects modeling. Extent of heterogeneity between studies was determined with the I2 test. Results Five studies (975 total patients, and 855 patients with individual patient-level data) were eligible for analysis, with a median follow-up of 8 years. Of the total cohort, 60.9%, 22.6%, and 16.5% of patients were classified by Decipher as low, intermediate, and high risk, respectively. The 10-year cumulative incidence metastases rates were 5.5%, 15.0%, and 26.7% ( P &lt; .001), respectively, for the three risk classifications. Pooling the study-specific Decipher HRs across the five studies resulted in an HR of 1.52 (95% CI, 1.39 to 1.67; I2 = 0%) per 0.1 unit. In multivariable analysis of individual patient data, adjusting for clinicopathologic variables, Decipher remained a statistically significant predictor of metastasis (HR, 1.30; 95% CI, 1.14 to 1.47; P &lt; .001) per 0.1 unit. The C-index for 10-year distant metastasis of the clinical model alone was 0.76; this increased to 0.81 with inclusion of Decipher. Conclusion The genomic classifier test, Decipher, can independently improve prognostication of patients postprostatectomy, as well as within nearly all clinicopathologic, demographic, and treatment subgroups. Future study of how to best incorporate genomic testing in clinical decision-making and subsequent treatment recommendations is warranted