Objectives: Determine the prognostic significance of rapid early tumor progression before radiation and chemotherapy for glioblastoma patients. Methods: A retrospective review of glioblastoma patients was performed. Rapid early progression (REP) was defined as new enhancing tumor or >25% increase in enhancement before radiotherapy. The pre/postoperative magnetic resonance imaging was compared with the preradiation magnetic resonance imaging to determine REP. A blinded review of imaging was performed. Kaplan-Meier curves were generated to compare progression-free and overall survival (OS). Univariate analysis was performed using the log-rank test for categorical variables and Cox proportional hazards for continuous variables. Multivariable logistic regression was performed to assess factors related to early progression and Cox proportional hazards model was used for multivariate analysis of OS. Results: Eighty-seven patients met entry criteria. A total of 52% of patients developed REP. The OS in the REP group was 11.5 months (95% confidence interval [CI]: 7.4-17.6) and 20.1 months (95% CI: 17.8-26.1) without REP (P=0.013). On multivariate analysis including significant prognostic factors, presence of REP was found to increase the risk of death (hazard ratio: 2.104, 95% CI: 1.235-3.583, P=0.006). A total of 74% of patients recurred in the site of REP. Conclusions: REP was common and independently predicted for a worse OS. Integrating REP with MGMT promotor methylation improved prognostic assessment. The site of REP was a common site of tumor progression. Our findings are hypothesis generating and may indicate a particular subset of glioblastoma patients who are resistant to current standard of care therapy. Further study to determine other molecular features of this group are underway.

African Americans are disproportionately affected by early-onset, high-grade malignancies. A fraction of this cancer health disparity can be explained by genetic differences between individuals of African or European descent. Here the wild-type Pro/Pro genotype at the TP53Pro72Arg (P72R) polymorphism (SNP: rs1042522) is more frequent in African Americans with cancer than in African Americans without cancer (51% vs. 37%), and is associated with a significant increase in the rates of cancer diagnosis in African Americans. To test the hypothesis that Tp53 allele–specific gene expression may contribute to African American cancer disparities, TP53 hemizygous knockout variants were generated and characterized in the RKO colon carcinoma cell line, which is wild type for TP53 and heterozygous at the TP53Pro72Arg locus. Transcriptome profiling, using RNAseq, in response to the DNA-damaging agent etoposide revealed a large number of Tp53-regulated transcripts, but also a subset of transcripts that were TP53Pro72Arg allele specific. In addition, a shRNA-library suppressor screen for Tp53 allele–specific escape from Tp53-induced arrest was performed. Several novel RNAi suppressors of Tp53 were identified, one of which, PRDM1β (BLIMP-1), was confirmed to be an Arg-specific transcript. Prdm1β silences target genes by recruiting H3K9 trimethyl (H3K9me3) repressive chromatin marks, and is necessary for stem cell differentiation. These results reveal a novel model for African American cancer disparity, in which the TP53 codon 72 allele influences lifetime cancer risk by driving damaged cells to differentiation through an epigenetic mechanism involving gene silencing. Implications: TP53 P72R polymorphism significantly contributes to increased African American cancer disparity. Mol Cancer Res; 12(7); 1029–41. ©2014 AACR.

There is little question that precision medicine will eventually be the standard of care in treatment with algorithms designed for therapy selection and is already being used in some specialties su...

Background/Objectives: Substance use disorder is a crisis impacting many people in the United States. This review aimed to identify the effect addictive substances have on the kynurenine pathway. Tryptophan is an essential amino acid metabolized by the serotonin and kynurenine pathways. The metabolites of these pathways play a role in the biological reward system. Addictive substances have been shown to cause imbalances in the ratios of these metabolites. With current treatment and therapeutic options being suboptimal, identifying biochemical mechanisms that are impacted during the use of addictive substances can provide alternative options for treatment or drug discovery. Methods: A systematic literature search was conducted to identify studies evaluating the relationship between substance use disorder and tryptophan metabolism through the kynurenine pathway. A total of 32 articles meeting eligibility criteria were used to review the relationship between the kynurenine pathway, tryptophan breakdown, and addictive substances. Results: The use of addictive substances dysregulates tryptophan metabolism and kynurenine metabolite concentrations. This imbalance directly affects the dopamine reward system and is thought to promote continued substance use. Conclusions: Further studies are needed to fully evaluate the metabolites of the kynurenine pathway, along with other options for treatment to repair the metabolite imbalance. Several possible therapeutics have been identified; drugs that restore homeostasis, such as Ro 61-8048 and natural products like Tinospora cordifolia or Decaisnea insignis, are promising options for the treatment of substance use disorder.

To teach first-year (P1) pharmacy students to apply the principles of pharmacogenomics underlying clinical pharmacotherapeutics to cancer patients. Using polymerase chain reaction (PCR) and high-resolution melting analysis of deoxyribonucleic acid (DNA) from colorectal cancer cell lines to determine the presence of somatic mutations for an oncogenic marker, students formulated the proper course of treatment for a patient with similar tumor genomics. In a postintervention survey, students highly rated the effectiveness of the laboratory session for learning pharmacogenomics, and subsequent examination scores reflected retention of principles and understanding of clinical application. The pharmacogenomic laboratory exercise prepared students to understand how genetic markers give clinical insight into the appropriate application of drugs in oncology pharmacotherapy. Further, the session inspired their interest in learning more about pharmacogenomics and their professional roles in personalized medicine.