KDM6A Loss Triggers an Epigenetic Switch That Disrupts Urothelial Differentiation and Drives Cell Proliferation in Bladder Cancer.

Disruption of KDM6A, a histone lysine demethylase, is one of the most common somatic alternations in bladder cancer. Insights into how KDM6A mutations affect the epigenetic landscape to promote carcinogenesis could help reveal potential new treatment approaches. Here, we demonstrated that KDM6A loss triggers an epigenetic switch that disrupts urothelial differentiation and induces a neoplastic state characterized by increased cell proliferation. In bladder cancer cells with intact KDM6A, FOXA1 interacted with KDM6A to activate genes instructing urothelial differentiation. KDM6A-deficient cells displayed simultaneous loss of FOXA1 target binding and genome-wide redistribution of the bZIP transcription factor ATF3, which in turn repressed FOXA1-target genes and activated cell-cycle progression genes. Importantly, ATF3 depletion reversed the cell proliferation phenotype induced by KDM6A deficiency. These data establish that KDM6A loss engenders an epigenetic state that drives tumor growth in an ATF3-dependent manner, creating a potentially targetable molecular vulnerability. SIGNIFICANCE: A gain-of-function epigenetic switch that disrupts differentiation is triggered by inactivating KDM6A mutations in bladder cancer and can serve as a potential target for novel therapies.

Antibiotic consumption and time to recovery from uncomplicated urinary tract infection: secondary analysis of observational data from a point-of-care test trial.

BACKGROUND: Randomised trials provide high-quality evidence on the effects of prescribing antibiotics for urinary tract infection (UTI) but may not reflect the effects in those who consume antibiotics. Moreover, they mostly compare different antibiotic types or regimens but rarely include a 'no antibiotic' group. AIM: To estimate the effect of antibiotic consumption, rather than prescription, on time to recovery in females with uncomplicated UTI. DESIGN AND SETTING: Secondary analysis of 14-day observational data from a point-of-care test trial for UTI in primary care in England, the Netherlands, Spain, and Wales, which ran from 2012 to 2014. Clinicians treated patients using their own judgement, providing immediate, delayed, or no antibiotic. METHOD: UTI-symptomatic females who either consumed or did not consume antibiotics during a 14-day follow-up were included. Antibiotic consumption was standardised across participants and grouped into either ≤3 or >3 standardised antibiotic days. To account for confounders, a robust propensity score matching analysis was conducted. Adjusted Kaplan-Meier and Cox proportional hazard models were employed to estimate time to recovery and hazard ratios, respectively. RESULTS: A total of n = 333 females who consumed antibiotics and n = 80 females who did not consume antibiotics were identified and included in the study. The adjusted median time to recovery was 2 days longer among patients who did not consume antibiotics (9 days, 95% confidence interval [CI] = 7 to 12) compared with those who did (7 days, 95% CI = 7 to 8). No difference was found between those who consumed ≤3 (7 days, 95% CI = 7 to 8) compared with >3 standardised antibiotic days (7 days, 95% CI = 6 to 9). CONCLUSION: Consuming antibiotics was associated with a reduction in self-reported time to recovery, but more antibiotics exposure was not associated with faster recovery in this study.

Genomic heterogeneity as a barrier to precision oncology in urothelial cancer.

Precision oncology relies on the accurate molecular characterization of individual patients with cancer at the time of treatment initiation. However, tumor molecular profiles are not static, and cancers continually evolve because of ongoing mutagenesis and clonal selection. Here, we performed genomic analyses of primary tumors, metastases, and plasma collected from individual patients to define the concordance of actionable genomic alterations and to identify drivers of metastatic disease progression. We observed a high degree of discordance of actionable genomic alterations, with 23% discordant between primary and metastatic disease sites. Among chromatin-modifying genes, ARID1A mutations, when discordant, were exclusive to the metastatic tumor samples. Our findings indicate that the high degree of lesion-to-lesion genomic heterogeneity may be a barrier to precision oncology approaches for bladder cancer and that circulating tumor DNA profiling may be preferred to tumor sequencing for a subset of patients.

AKT1 E17K Inhibits Cancer Cell Migration by Abrogating ß-Catenin Signaling.

Mutational activation of the PI3K/AKT pathway is among the most common pro-oncogenic events in human cancers. The clinical utility of PI3K and AKT inhibitors has, however, been modest to date. Here, we used CRISPR-mediated gene editing to study the biological consequences of AKT1 E17K mutation by developing an AKT1 E17K-mutant isogenic system in a TP53-null background. AKT1 E17K expression under the control of its endogenous promoter enhanced cell growth and colony formation, but had a paradoxical inhibitory effect on cell migration and invasion. The mechanistic basis by which activated AKT1 inhibited cell migration and invasion was increased E-cadherin expression mediated by suppression of ZEB1 transcription via altered ß-catenin subcellular localization. This phenotypic effect was AKT1-specific, as AKT2 activation had the opposite effect, a reduction in E-cadherin expression. Consistent with the opposing effects of AKT1 and AKT2 activation on E-cadherin expression, a pro-migratory effect of AKT1 activation was not observed in breast cancer cells with PTEN loss or expression of an activating PIK3CA mutation, alterations which induce the activation of both AKT isoforms. The results suggest that the use of AKT inhibitors in patients with breast cancer could paradoxically accelerate metastatic progression in some genetic contexts and may explain the frequent coselection for CDH1 mutations in AKT1-mutated breast tumors. IMPLICATIONS: AKT1 E17K mutation in breast cancer impairs migration/invasiveness via sequestration of ß-catenin to the cell membrane leading to decreased ZEB1 transcription, resulting in increased E-cadherin expression and a reversal of epithelial-mesenchymal transition.

Leveraging Systematic Functional Analysis to Benchmark an In Silico Framework Distinguishes Driver from Passenger MEK Mutants in Cancer.

Despite significant advances in cancer precision medicine, a significant hurdle to its broader adoption remains the multitude of variants of unknown significance identified by clinical tumor sequencing and the lack of biologically validated methods to distinguish between functional and benign variants. Here we used functional data on MAP2K1 and MAP2K2 mutations generated in real-time within a co-clinical trial framework to benchmark the predictive value of a three-part in silico methodology. Our computational approach to variant classification incorporated hotspot analysis, three-dimensional molecular dynamics simulation, and sequence paralogy. In silico prediction accurately distinguished functional from benign MAP2K1 and MAP2K2 mutants, yet drug sensitivity varied widely among activating mutant alleles. These results suggest that multifaceted in silico modeling can inform patient accrual to MEK/ERK inhibitor clinical trials, but computational methods need to be paired with laboratory- and clinic-based efforts designed to unravel variabilities in drug response. SIGNIFICANCE: Leveraging prospective functional characterization of MEK1/2 mutants, it was found that hotspot analysis, molecular dynamics simulation, and sequence paralogy are complementary tools that can robustly prioritize variants for biologic, therapeutic, and clinical validation.See related commentary by Whitehead and Sebolt-Leopold, p. 4042.

Precision Oncology: Three Small Steps Forward.

Only a subset of cancer patients currently benefit from personalized treatment approaches. Detection of actionable drug targets in cell-free DNA, more comprehensive molecular profiling integrating transcriptional analyses, and personalized combination regimens all hold promise in expanding the benefits of personalized oncology to larger numbers of cancer patients.

Activity of M3814, an Oral DNA-PK Inhibitor, In Combination with Topoisomerase II Inhibitors in Ovarian Cancer Models.

DNA-dependent protein kinase (DNA-PK) has been shown to play a crucial role in repair of DNA double-strand breaks, facilitating nonhomologous end-joining. DNA-PK inhibitors have the potential to block DNA repair and therefore enhance DNA-damaging agents. M3814 is a DNA-PK inhibitor that has shown preclinical activity in combination with DNA-damaging agents, including radiotherapy and topoisomerase II inhibitors. Here we evaluated the activity of M3814 in combination with multiple topoisomerase II inhibitors, doxorubicin, etoposide, and pegylated liposomal doxorubicin (PLD) in vivo, utilizing ovarian cancer xenografts. Using cell lines representative of P53 wild-type ovarian cancer (A2780), and P53 mutant ovarian cancer (SKOV3), cells were implanted in the flank of athymic nude female mice. Mice were treated with vehicle, M3814 alone, topoisomerase II inhibitor alone, and M3814 in combination with topoisomerase II inhibitor, and change in tumor volume over time was documented. The addition of M3814 was well tolerated. We demonstrated that M3814 shows limited efficacy as a single agent in ovarian cancer models. The combination of M3814 with PLD showed enhanced activity over PLD as a single agent. Further study of this combination is warranted.

Feasibility and safety of a novel electromagnetic device for small-bore feeding tube placement.

BACKGROUND: Misplacement of enteral feeding tubes (EFT) in the lungs is a serious and potentially fatal event. A recent Food and Drug Administration Patient Safety Alert emphasized the need for improved technology for the safe and effective delivery of EFTs. OBJECTIVE: We investigated the feasibility and safety of ENvue, a novel electromagnetic tracking system (EMTS) to aid qualified operators in the placement of EFT. METHODS: This is a prospective, single-arm study of patients in intensive care units at two US hospitals who required EFTs. The primary outcome was appropriate placement of EFTs without occurrence of guidance-related adverse events (AEs), as confirmed by both EMTS and radiography. Secondary outcomes were reconfirmation of the EFT tip location at a follow-up visit using the EMTS compared with radiography, tube retrograde migration from initial location and AEs. RESULTS: Sixty-five patients were included in the intent-to-treat analysis. EFTs were successfully placed in 57 patients. In eight patients, placement was unsuccessful due to anatomic abnormalities. According to both the EMTS and radiography, no lung placements occurred. No pneumothoraces were reported, nor any guidance-related AEs. Precise agreement of tube tip location was achieved between the EMTS evaluations and radiographs for 56 of the 58 (96.5%) successful placements (one patient had two placements). Tube tip location was re-confirmed 12-49 hours after EFT insertion by the EMTS and radiographs in 48 patients (84%). For 43/48 patients (89.5%), full agreement between the EMTS and radiography evaluations was observed. For the five remaining patients, the misalignment between the evaluations was within the gastrointestinal tract. Retrograde migration from the initial location was observed in 4/49 patients (8%). CONCLUSION: A novel electromagnetic system demonstrated feasibility and safety of real-time and follow-up tracking of EFT placement into the stomach and small intestine, as confirmed by radiographs. No inadvertent placements into the lungs were documented. LEVEL OF EVIDENCE: Level V (large case series).