Mapping of DDX11 genetic interactions defines sister chromatid cohesion as the major dependency.

DDX11/Chl1R is a conserved DNA helicase with roles in genome maintenance, DNA replication, and chromatid cohesion. Loss of DDX11 in humans leads to the rare cohesinopathy Warsaw breakage syndrome. DDX11 has also been implicated in human cancer where it has been proposed to have an oncogenic role and possibly to constitute a therapeutic target. Given the multiple roles of DDX11 in genome stability and its potential as an anticancer target, we set out to define a complete genetic interaction profile of DDX11 loss in human cell lines. Screening the human genome with clustered regularly interspaced short palindromic repeats (CRISPR) guide RNA drop out screens in DDX11-wildtype (WT) or DDX11-deficient cells revealed a strong enrichment of genes with functions related to sister chromatid cohesion. We confirm synthetic lethal relationships between DDX11 and the tumor suppressor cohesin subunit STAG2, which is frequently mutated in several cancer types and the kinase HASPIN. This screen highlights the importance of cohesion in cells lacking DDX11 and suggests DDX11 may be a therapeutic target for tumors with mutations in STAG2.

Novel Methionine Aminopeptidase 2 Inhibitor M8891 Synergizes with VEGF Receptor Inhibitors to Inhibit Tumor Growth of Renal Cell Carcinoma Models.

N-terminal processing by methionine aminopeptidases (MetAP) is a crucial step in the maturation of proteins during protein biosynthesis. Small-molecule inhibitors of MetAP2 have antiangiogenic and antitumoral activity. Herein, we characterize the structurally novel MetAP2 inhibitor M8891. M8891 is a potent, selective, reversible small-molecule inhibitor blocking the growth of human endothelial cells and differentially inhibiting cancer cell growth. A CRISPR genome-wide screen identified the tumor suppressor p53 and MetAP1/MetAP2 as determinants of resistance and sensitivity to pharmacologic MetAP2 inhibition. A newly identified substrate of MetAP2, translation elongation factor 1-alpha-1 (EF1a-1), served as a pharmacodynamic biomarker to follow target inhibition in cell and mouse studies. Robust angiogenesis and tumor growth inhibition was observed with M8891 monotherapy. In combination with VEGF receptor inhibitors, tumor stasis and regression occurred in patient-derived xenograft renal cell carcinoma models, particularly those that were p53 wild-type, had Von Hippel-Landau gene (VHL) loss-of-function mutations, and a mid/high MetAP1/2 expression score.

Topoisomerase 1 Inhibition in MYC-Driven Cancer Promotes Aberrant R-Loop Accumulation to Induce Synthetic Lethality.

MYC is a central regulator of gene transcription and is frequently dysregulated in human cancers. As targeting MYC directly is challenging, an alternative strategy is to identify specific proteins or processes required for MYC to function as a potent cancer driver that can be targeted to result in synthetic lethality. To identify potential targets in MYC-driven cancers, we performed a genome-wide CRISPR knockout screen using an isogenic pair of breast cancer cell lines in which MYC dysregulation is the switch from benign to transformed tumor growth. Proteins that regulate R-loops were identified as a potential class of synthetic lethal targets. Dysregulated MYC elevated global transcription and coincident R-loop accumulation. Topoisomerase 1 (TOP1), a regulator of R-loops by DNA topology, was validated to be a vulnerability in cells with high MYC activity. Genetic knockdown of TOP1 in MYC-transformed cells resulted in reduced colony formation compared with control cells, demonstrating synthetic lethality. Overexpression of RNaseH1, a riboendonuclease that specifically degrades R-loops, rescued the reduction in clonogenicity induced by TOP1 deficiency, demonstrating that this vulnerability is driven by aberrant R-loop accumulation. Genetic and pharmacologic TOP1 inhibition selectively reduced the fitness of MYC-transformed tumors in vivo. Finally, drug response to TOP1 inhibitors (i.e., topotecan) significantly correlated with MYC levels and activity across panels of breast cancer cell lines and patient-derived organoids. Together, these results highlight TOP1 as a promising target for MYC-driven cancers. SIGNIFICANCE: CRISPR screening reveals topoisomerase 1 as an immediately actionable vulnerability in cancers harboring MYC as a driver oncoprotein that can be targeted with clinically approved inhibitors.

Microfluidically-generated Encapsulated Spheroids (µ-GELS): An All-Aqueous Droplet Microfluidics Platform for Multicellular Spheroids Generation.

Spheroids are three-dimensional clusters of cells that serve as in vitro tumor models to recapitulate in vivo morphology. A limitation of many existing on-chip platforms for spheroid formation is the use of cytotoxic organic solvents as the continuous phase in droplet generation processes. All-aqueous methods do not contain cytotoxic organic solvents but have so far been unable to achieve complete hydrogel gelation on chip. Here, we describe an enhanced droplet microfluidic platform that achieves on-chip gelation of all-aqueous hydrogel multicellular spheroids (MCSs). Specifically, we generate dextran-alginate droplets containing MCF-7 breast cancer cells, surrounded by polyethylene glycol, at a flow-focusing junction. Droplets then travel to a second flow-focusing junction where they interact with calcium chloride and gel on chip to form hydrogel MCSs. On-chip gelation of the MCSs is possible here because of an embedded capillary at the second junction that delays the droplet gelation, which prevents channel clogging problems that would otherwise exist. In drug-free experiments, we demonstrate that MCSs remain viable for 6 days. We also confirm the applicability of this system for cancer drug testing by observing that dose-dependent cell death is achievable using doxorubicin.

Real-world utilization and outcomes of docetaxel among older men with metastatic prostate cancer: a retrospective population-based cohort study in Canada.

BACKGROUND: The adoption of docetaxel for systemic treatment of metastatic prostate cancer (PCa), in both castration-sensitive (mCSPC) and castration-resistant (mCRPC) settings, is poorly understood. This study examined the real-world utilization of docetaxel in these patients and their outcomes. METHODS: A retrospective population-based study used administrative data from Ontario, Canada, to identify men aged ≥66 years who were diagnosed with de novo mCSPC or mCRPC between 2014 and 2019 and received docetaxel. The study assessed treatment tolerability and toxicity, and survival in both cohorts. Descriptive and comparative statistical analysis were conducted. RESULTS: The study identified 11.2% (399/3556) and 13.2% (203/1534) patients diagnosed with de novo mCSPC and with mCRPC who received docetaxel respectively. The median age in both cohorts was 72 years (IQR: 68-76). Overall, 43.9% (n = 175) patients with de novo mCSPC and 52.1% (n = 85) with mCRPC completed ≥6 cycles of docetaxel. Over two-fifth also needed dose adjustments in both cohorts. Hospitalization or emergency department visit for febrile neutropenia were noted in 15.8% (n = 63) of de novo mCSPC patients and similarly in 19% (n = 31) of mCRPC cohort. The median survival of PCa patients who completed ≥6 cycles of docetaxel was significantly longer relative to those who completed <4 cycles: 32.7 vs. 23.5 months (p < 0.001) for mCSPC and 20.5 vs. 10.7 (p = 0.012) for mCRPC respectively. CONCLUSIONS: In this population-based study of elderly patients with metastatic PCa, treatment with docetaxel was associated with poor tolerability and higher toxicity compared with clinical trials. Receipt of limited cycles and reduced overall dose of docetaxel were associated with inferior overall survival.

Patterns of care for non-metastatic castration-resistant prostate cancer: A population-based study.

Objectives: To describe patterns of practice of PSA testing and imaging for Ontario men receiving continuous ADT for the treatment of non-metastatic castration-resistant prostate cancer (nmCRPC). Patients and Methods: This was a retrospective, longitudinal, population-based study of administrative health data from 2008 to 2019. Men 65 years and older receiving continuous androgen deprivation therapy (ADT) with documented CRPC were included. An administrative proxy definition was applied to capture patients with nmCRPC and excluded those with metastatic disease. Patients were indexed upon progression to CRPC and were followed until death or end of study period to assess frequency of monitoring with PSA tests and conventional imaging. A 2-year look-back window was used to assess patterns of care leading up to CRPC as well as baseline covariates. Results: At a median follow-up of 40.1 months, 944 patients with nmCRPC were identified. Their median time from initiation of continuous ADT to CRPC was 26.0 months. 60.7% of patients had their PSA measured twice or fewer in the year prior to index, and 70.7% patients did not receive any imaging in the year following progression to CRPC. Throughout the study period, 921/944 (97.6%) patients with CRPC progressed to high-risk (HR-CRPC) with PSA doubling time ≤ 10 months, of which more than half received fewer than three PSA tests in the year prior to developing HR-CRPC, and 30.9% received no imaging in the subsequent year. Conclusion: PSA testing and imaging studies are underutilized in a real-world setting for the management of nmCRPC, including those at high risk of developing metastatic disease. Infrequent monitoring impedes proper risk stratification, disease staging and detection of treatment failure and/or metastases, thereby delaying the necessary treatment intensification with life-prolonging therapies. Adherence to guideline recommendations and the importance of timely staging should be reinforced to optimize patient outcomes.

Context-dependent regulation of ferroptosis sensitivity.

Ferroptosis is an important mediator of pathophysiological cell death and an emerging target for cancer therapy. Whether ferroptosis sensitivity is governed by a single regulatory mechanism is unclear. Here, based on the integration of 24 published chemical genetic screens combined with targeted follow-up experimentation, we find that the genetic regulation of ferroptosis sensitivity is highly variable and context-dependent. For example, the lipid metabolic gene acyl-coenzyme A (CoA) synthetase long chain family member 4 (ACSL4) appears far more essential for ferroptosis triggered by direct inhibition of the lipid hydroperoxidase glutathione peroxidase 4 (GPX4) than by cystine deprivation. Despite this, distinct pro-ferroptotic stimuli converge upon a common lethal effector mechanism: accumulation of lipid peroxides at the plasma membrane. These results indicate that distinct genetic mechanisms regulate ferroptosis sensitivity, with implications for the initiation and analysis of this process in vivo.

Phase transition modulation and biophysical characterization of biomolecular condensates using microfluidics.

Membraneless organelles (MLOs) formed through liquid-liquid phase separation (LLPS) are becoming increasingly relevant to understanding viral-host interactions, neurodegenerative disease, and cancer. The modulation of LLPS involves many parameters and components. To describe these modulators, typical in vitro studies require laborious, manual sample preparation of different concentrations and costly biological reagents. Here, we introduce a minimal reagent, microfluidic platform to systematically generate samples of different concentrations and trigger phase separation. We demonstrate the platform's utility by constructing phase diagrams describing the modulation of LLPS using an aqueous two-phase system (ATPS) and an MLO-based phase separating system. We also show on-chip biophysical characterization typical of in vitro studies. We expect that this platform will be utilized by scientists to study the growing number of MLOs and inform clinical treatments for pathology related to LLPS.

Real-world use of systemic therapies in men with metastatic castration resistant prostate cancer (mCRPC) in Canada.

BACKGROUND: Management of advanced prostate cancer has evolved rapidly with the availability of multiple systemic treatments such as androgen-receptor axis-targeted therapies (ARATs), taxane-based chemotherapy, radium-223, and other approaches. However, limited data exists on real-world treatment selection and clinical outcomes. This study examines the utilization and survival impact of these therapies in men with metastatic castration-resistant prostate cancer (mCRPC) in the real-world setting of Ontario, Canada. METHODS: This study was a retrospective, longitudinal, population-based study of administrative claims data between January 2016 and April 2020. Men ≥ 66 years with mCRPC receiving advanced treatment were included. Patients were indexed on the day they initiated mCRPC treatment and followed up until death or end of study period to assess treatment and survival. Multinomial regression was used to model the association between baseline covariates, treatment and survival. RESULTS: Median age was 75 years among the 944 mCRPC patients who received life-prolonging therapies during this time period. Over 90% of patients used an ARAT as a first-line therapy, and 71.5% received only first-line therapy before death or censoring. Of patients that received two or more lines, over 80% received subsequent therapy with a different mechanism of action. Median overall survival was 18.9 months. CONCLUSIONS: ARATs have become the predominant first-line systemic treatment option for mCRPC patients in recent years. Notably, the majority of patients received only a single line of life-prolonging therapy after developing mCRPC. In keeping with the recognized efficacy-effectiveness gap, real-world outcomes in this cohort appear poorer than in clinical trials.

Ask the parents: Testing the acceptability and usability of a hypospadias decision aid.

INTRODUCTION: In previous work, we engaged key stakeholders to create a web-based decision aid (DA) prototype to facilitate shared decision making about hypospadias. OBJECTIVE: The study's objective was to use a human-centered design approach to assess the DA's acceptability and usability and revise it prior to pilot testing. METHODS: We recruited English-speaking parents (≥18 years old) of sons with hypospadias (≤5 years) for a two-phase process of semi-structured phone/video interviews to obtain feedback about our DA prototype. DA webpages included: "Hypospadias," "Surgery Basics," "No Surgery," "Family Stories," "Help Me Decide," and "FAQs." In both phases, participants viewed the DA using the "think aloud" technique and completed several validated scales to evaluate its acceptability and usability. In phase 1, we collected feedback about the "Homepage" organization, values clarification methods (VCM), and webpage content. In phase 2, participants searched the DA for answers to hypospadias-related questions, provided feedback on testimonial videos and VCM, and shared their preferences about data visualizations. All interviews were audio recorded. After each phase, transcripts were qualitatively analyzed to identify key areas for revision. Revisions were made between phase 1 and 2 to improve the DA's acceptability and usability. RESULTS: We interviewed 20 participants (10/phase): median age 33.7 years, 60% female, 80% White. Mean score on the Preparation for Decision Making Scale: 86.8 (out of 100). We revised: 1) VCM, focusing on pros/cons of surgery and question prompts, 2) "Homepage," adding webpage descriptions (Extended Summary Figure), 3) menu organization, 4) "Surgery Day" webpage, adding general anesthesia risk information, and 5) "Hypospadias" webpage, adding an icon bar graph to help participants visualize statistics. Participants thought the testimonial videos were relatable and the VCMs would prepare them for their visit with their child's urologist. DISCUSSION: Ours is the first parent-centered DA developed and pre-tested for hypospadias. Using validated usability and acceptability scales, participants highly rated the DA in helping them arrive at a decision about surgery. Study limitations include the sample's lack of diversity (i.e., educated, health literate) and participants already decided about their son's hypospadias management before enrolling. To learn more about the DA's usability and acceptability, we plan to pilot test it in a clinical setting. CONCLUSIONS: Participants found our DA informative in understanding hypospadias. There was a high perceived level of preparation for hypospadias decision making. Participatory research methods, such as "think aloud," may be helpful when testing DAs as they privilege the patient's experience.

Real-World Use of Androgen-Deprivation Therapy: Intensification Among Older Canadian Men With de Novo Metastatic Prostate Cancer.

Background: Despite the wealth of evidence demonstrating the efficacy of treatment intensification beyond androgen-deprivation therapy (ADT) among patients with de novo metastatic castration-sensitive prostate cancer (mCSPC), little is known of its real-world use. This study examined the real-world uptake of ADT treatment intensification among older men in a large Canadian province. Methods: We performed a retrospective population-based cohort study using province-wide linked administrative data in Ontario, Canada. Patients 66 years of age and older with de novo mCSPC were included and their treatment with conventional ADT-based regimens, ADT plus next-generation androgen receptor axis-targeted therapy, and ADT plus docetaxel were identified and stratified by time. Results: From 2014 to 2019, 3556 patients were identified with de novo mCSPC. Most patients (n = 2794 [78.6%]) were treated with a conventional ADT regimen, whereas 399 (11.2%) patients received ADT intensification with docetaxel and 52 (1.5%) patients received abiraterone acetate plus prednisone. In a time-stratified analysis of ADT intensification before and after the pivotal AA+P trial (LATITUDE), AA+P uptake increased from 0.5% to 3.0%, whereas docetaxel use dropped from 12.0% to 10.0%. The median survival of the study population was 18 months (interquartile range = 10-31). Conclusions: The majority of patients with de novo mCSPC are treated with ADT alone in the Canadian real-world setting, despite randomized clinical trial evidence of benefit with the use of ADT-intensified regimens. As ADT treatment intensification is substantially underused, better understanding of the barriers to treatment and targeted education to address them are needed.

FAM72A antagonizes UNG2 to promote mutagenic repair during antibody maturation.

Activation-induced cytidine deaminase (AID) catalyses the deamination of deoxycytidines to deoxyuracils within immunoglobulin genes to induce somatic hypermutation and class-switch recombination1,2. AID-generated deoxyuracils are recognized and processed by subverted base-excision and mismatch repair pathways that ensure a mutagenic outcome in B cells3-6. However, why these DNA repair pathways do not accurately repair AID-induced lesions remains unknown. Here, using a genome-wide CRISPR screen, we show that FAM72A is a major determinant for the error-prone processing of deoxyuracils. Fam72a-deficient CH12F3-2 B cells and primary B cells from Fam72a-/- mice exhibit reduced class-switch recombination and somatic hypermutation frequencies at immunoglobulin and Bcl6 genes, and reduced genome-wide deoxyuracils. The somatic hypermutation spectrum in B cells from Fam72a-/- mice is opposite to that observed in mice deficient in uracil DNA glycosylase 2 (UNG2)7, which suggests that UNG2 is hyperactive in FAM72A-deficient cells. Indeed, FAM72A binds to UNG2, resulting in reduced levels of UNG2 protein in the G1 phase of the cell cycle, coinciding with peak AID activity. FAM72A therefore causes U·G mispairs to persist into S phase, leading to error-prone processing by mismatch repair. By disabling the DNA repair pathways that normally efficiently remove deoxyuracils from DNA, FAM72A enables AID to exert its full effects on antibody maturation. This work has implications in cancer, as the overexpression of FAM72A that is observed in many cancers8 could promote mutagenesis.

Paralogous synthetic lethality underlies genetic dependencies of the cancer-mutated gene STAG2.

STAG2, a component of the mitotically essential cohesin complex, is highly mutated in several different tumour types, including glioblastoma and bladder cancer. Whereas cohesin has roles in many cancer-related pathways, such as chromosome instability, DNA repair and gene expression, the complex nature of cohesin function has made it difficult to determine how STAG2 loss might either promote tumorigenesis or be leveraged therapeutically across divergent cancer types. Here, we have performed whole-genome CRISPR-Cas9 screens for STAG2-dependent genetic interactions in three distinct cellular backgrounds. Surprisingly, STAG1, the paralog of STAG2, was the only negative genetic interaction that was shared across all three backgrounds. We also uncovered a paralogous synthetic lethal mechanism behind a genetic interaction between STAG2 and the iron regulatory gene IREB2 Finally, investigation of an unusually strong context-dependent genetic interaction in HAP1 cells revealed factors that could be important for alleviating cohesin loading stress. Together, our results reveal new facets of STAG2 and cohesin function across a variety of genetic contexts.

Split appendix catheterizable urinary channels are at no higher risk of undergoing revision compared to channels made with the intact appendix.

OBJECTIVE: To assess long-term APV and split-appendix MACE durability and to compare split and intact appendix APVs in a large patient cohort. METHODS: This retrospective cohort study included consecutive patients ≤21 years old undergoing an APV at our institution (1990-2019). Main outcomes were stomal and subfascial revisions. Kaplan Meier survival and Cox proportional hazards analysis were used. RESULTS: A total of 339 patients underwent APV creation at a median 7.4 years old (41% female vs. 59% male; 37% umbilical stoma vs. 63% other). In total, 36 patients underwent a stomal revision and 19 a subfascial revision (median channel follow-up 6.3 years). On survival analysis, the risk of stomal revision of the APV was 9.1% at 5 years, 12.6% at 10 years and 16.5% at 15 years. Risk of subfascial revision of the APV was 5.1% at 5 years, 7.0% at 10 years and 8.2% at 15 years. A split-appendix APV was performed in 118 (34.8%) of 339 patients. They had a shorter follow-up compared to those with an intact APV (5.1 vs. 7.0 years, p = 0.03). After correcting for differential follow-up time, there was no significant difference between groups for stomal revisions (HR 1.11, p = 0.76) or subfascial revisions (HR 0.80, p = 0.67, Figure). Risk of APV stomal revision was independent of stomal location and age at surgery (p ≥ 0.37). Similarly, risk of subfascial APV revision was independent of stomal location and age at surgery (p ≥ 0.18). Risk of stomal revision for split-appendix MACE channels was 16.2% at 5, 10 and 15 years (similar to split-appendix APV and all APVs, p ≥ 0.26). Risk of MACE subfascial revision was 5.5% at 5 years, 5.5% at 10 years and 14.7% at 15 years (similar to split-appendix APV and all APVs, p ≥ 0.36). COMMENT: We focused on surgical complications, as these entail the highest morbidity, however, we did not assess non-surgical, percutaneous or endoscopic management which also impact long-term outcome and patient quality of life. We did not compare the outcomes of the split-appendix MACE to an intact-appendix MACE cohort, as this patient population was not captured in this review. CONCLUSIONS: The split-appendix technique has durable long-term results for both the APV and MACE channels, which are comparable to the technique utilizing the intact appendix. Channel complications occur over the channel's lifetime, as 1 in 8 APVs in the entire cohort underwent a stomal revision and 1 in 14 APVs underwent a subfascial revision at 10 years after surgery.

Prognostic Association between Common Laboratory Tests and Overall Survival in Elderly Men with De Novo Metastatic Castration Sensitive Prostate Cancer: A Population-Based Study in Canada.

De novo cases of metastatic prostate cancer (mCSPC) are associated with poorer prognosis. To assist in clinical decision-making, we aimed to determine the prognostic utility of commonly available laboratory-based markers with overall survival (OS). In a retrospective population-based study, a cohort of 3556 men aged ≥66 years diagnosed with de novo mCSPC between 2014 and 2019 was identified in Ontario (Canada) administrative database. OS was assessed by using the Kaplan-Meier method. Multivariate Cox regression analysis was performed to evaluate the association between laboratory markers and OS adjusting for patient and disease characteristics. Laboratory markers that were assessed include neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), albumin, hemoglobin, serum testosterone and PSA kinetics. Among the 3556 older men with de novo mCSPC, their median age was 77 years (IQR: 71-83). The median survival was 18 months (IQR: 10-31). In multivariate analysis, a statistically significant association with OS was observed with all the markers (NLR, PLR, albumin, hemoglobin, PSA decrease, reaching PSA nadir and a 50% PSA decline), except for testosterone levels. Our findings support the use of markers of systemic inflammation (NLR, PLR and albumin), hemoglobin and PSA metrics as prognostic indicators for OS in de novo mCSPC.

User-centered development of a hypospadias decision aid prototype.

INTRODUCTION: Many parents who choose hypospadias repair for their sons experience decisional conflict (DC) and decisional regret (DR). We previously found that parental decision-making about hypospadias surgery is a complex process characterized by cyclic information-seeking to alleviate anxiety and confusion. OBJECTIVE: The objective of this study was to engage parents of hypospadias patients and pediatric providers in the co-design of a decision aid (DA) prototype to facilitate shared decision-making about hypospadias surgery and address DC and DR. METHODS: From August 2018 to January 2019, we conducted three co-design workshops with parents of hypospadias patients, pediatric urology and general pediatric providers to discuss their recommendations for a DA prototype. Activities were audio recorded and professionally transcribed. Transcripts and worksheets were analyzed by six coders using qualitative analysis to identify key aspects of a hypospadias DA desired by stakeholders. We conducted a collaborative design and prototyping session to establish key features and requirements, created a content map visualizing this work, and then developed a DA prototype. RESULTS: Parent participants included 6 mothers and 4 fathers: 8 Caucasian, 2 African-American; median age 31 years. Providers included pediatric urology (n = 7) and general pediatric providers (n = 10): median age 47.5 years, 83.3% Caucasian, 58.3% male, 58.3% MD's and 41.7% nurse practitioners. Participants created user-friendly, interactive DA prototypes with "24/7" availability that had three key functions: 1) provide accurate, customizable, educational content, 2) connect parents with each other, and 3) engage them in a decision-making activity. The prototype consisted of five modules (Extended Summary Figure). "Hypospadias Basics" includes epidemiology and a hypospadias severity scale. "Surgery Basics" includes goals, illustrated steps, and pros/cons of surgery. "Testimonials" includes videos of parents and adolescents discussing their experiences. "Help me Decide" includes a decisional conflict scale and a decision-making activity (i.e. values clarification method). "Frequently Asked Questions" covers general hypospadias information, perioperative expectations and a review of postoperative care. DISCUSSION: To our knowledge, this is the first DA prototype developed for a pediatric urology condition using a human-centered design approach to engage many key stakeholders in the development process. One limitation of this study is the small population sampled, which limits generalizability and means that our findings may not reflect the views of all parents or pediatric providers involved in hypospadias decision-making. CONCLUSIONS: We created a parent-centered hypospadias DA prototype that provides decision support in an online, interactive format. Future directions include further testing with usability experts, providers and parents.

User testing of a hypospadias decision aid prototype at a pediatric medical conference.

INTRODUCTION: Based on our previous qualitative work, we created a web-based decision aid (DA) prototype to facilitate shared decision-making regarding hypospadias. OBJECTIVE: The objective of this study was to obtain rapid feedback on the prototype as part of an iterative, human-centered design process. METHODS: We conducted this study at a statewide, pediatric educational conference in May 2019, recruiting attendees by verbal/written announcements. The DA consisted of: hypospadias overview and surgery "storyboard," frequently asked questions, parent testimonials, and a values clarification exercise. Participants viewed the DA on a tablet as they participated in semi-structured, qualitative interviews covering website acceptability, usability, and preference for surgical photographs versus illustrations. Three coders used qualitative content analysis to identify themes and resolved disagreements by consensus. RESULTS: Of 295 conference attendees, all 50 who approached us agreed to participate. Responses from 49 participants were available for analysis: 67% female, ages 20-69, 65% Caucasian, 55% MDs. 96% of participants thought the website design matched its purpose; 59.1% preferred surgical illustrations, 8.2% preferred photos, 30.6% preferred both and 2.0% did not like either. Participants recommended improvements in: a) usability/accessibility (e.g. site navigation, visual layout, page length), b) content coverage (e.g. epidemiology, consequences of no/delayed surgery, lifelong risks), c) parent-centeredness (e.g. reading level/writing style) and d) implementation (provider tools, printable handouts). The Extended Summary Figure shows a revised image of the first step of a hypospadias repair based on feedback about participants' preferences for illustrations rather than photographs. DISCUSSION: The main strength of our study was the valuable feedback we obtained to inform critical revisions of the DA prototype. We also demonstrated the feasibility and efficacy of a conducting a usability evaluation of a web-based DA in a medical conference setting. One limitation of this study is that the relatively small population sampled limits generalizability and our findings may not reflect the views of all providers who care for hypospadias patients. CONCLUSIONS: The vast majority of providers thought that the design of the Hypospadias Homepage matched its purpose and most preferred surgical illustrations rather than photos to demonstrate the steps of hypospadias surgery. Based on their feedback, we plan to focus our efforts in the following areas: 1) improvement of navigation/menus, 2) reduction in the amount of text per page, 3) expansion of specific content coverage and 4) inclusion of "parent-friendly" visuals such as infographics to represent quantitative data and colorful illustrations to depict hypospadias and its surgical repair.

Functional genomic landscape of cancer-intrinsic evasion of killing by T cells.

The genetic circuits that allow cancer cells to evade destruction by the host immune system remain poorly understood1-3. Here, to identify a phenotypically robust core set of genes and pathways that enable cancer cells to evade killing mediated by cytotoxic T lymphocytes (CTLs), we performed genome-wide CRISPR screens across a panel of genetically diverse mouse cancer cell lines that were cultured in the presence of CTLs. We identify a core set of 182 genes across these mouse cancer models, the individual perturbation of which increases either the sensitivity or the resistance of cancer cells to CTL-mediated toxicity. Systematic exploration of our dataset using genetic co-similarity reveals the hierarchical and coordinated manner in which genes and pathways act in cancer cells to orchestrate their evasion of CTLs, and shows that discrete functional modules that control the interferon response and tumour necrosis factor (TNF)-induced cytotoxicity are dominant sub-phenotypes. Our data establish a central role for genes that were previously identified as negative regulators of the type-II interferon response (for example, Ptpn2, Socs1 and Adar1) in mediating CTL evasion, and show that the lipid-droplet-related gene Fitm2 is required for maintaining cell fitness after exposure to interferon-γ (IFNγ). In addition, we identify the autophagy pathway as a conserved mediator of the evasion of CTLs by cancer cells, and show that this pathway is required to resist cytotoxicity induced by the cytokines IFNγ and TNF. Through the mapping of cytokine- and CTL-based genetic interactions, together with in vivo CRISPR screens, we show how the pleiotropic effects of autophagy control cancer-cell-intrinsic evasion of killing by CTLs and we highlight the importance of these effects within the tumour microenvironment. Collectively, these data expand our knowledge of the genetic circuits that are involved in the evasion of the immune system by cancer cells, and highlight genetic interactions that contribute to phenotypes associated with escape from killing by CTLs.

Systematic mapping of genetic interactions for de novo fatty acid synthesis identifies C12orf49 as a regulator of lipid metabolism.

The de novo synthesis of fatty acids has emerged as a therapeutic target for various diseases, including cancer. Because cancer cells are intrinsically buffered to combat metabolic stress, it is important to understand how cells may adapt to the loss of de novo fatty acid biosynthesis. Here, we use pooled genome-wide CRISPR screens to systematically map genetic interactions (GIs) in human HAP1 cells carrying a loss-of-function mutation in fatty acid synthase (FASN), whose product catalyses the formation of long-chain fatty acids. FASN-mutant cells show a strong dependence on lipid uptake that is reflected in negative GIs with genes involved in the LDL receptor pathway, vesicle trafficking and protein glycosylation. Further support for these functional relationships is derived from additional GI screens in query cell lines deficient in other genes involved in lipid metabolism, including LDLR, SREBF1, SREBF2 and ACACA. Our GI profiles also identify a potential role for the previously uncharacterized gene C12orf49 (which we call LUR1) in regulation of exogenous lipid uptake through modulation of SREBF2 signalling in response to lipid starvation. Overall, our data highlight the genetic determinants underlying the cellular adaptation associated with loss of de novo fatty acid synthesis and demonstrate the power of systematic GI mapping for uncovering metabolic buffering mechanisms in human cells.

Real-world evidence in patient-reported outcomes (PROs) of metastatic castrate-resistant prostate cancer (mCRPC) patients treated with abiraterone acetate + prednisone (AA+P) across Canada: Final results of COSMiC.

INTRODUCTION: Abiraterone acetate plus prednisone (AA+P) has shown to significantly improve survival. COSMiC, a Canadian Observational Study in Metastatic Cancer of the Prostate, set out to prospectively amass real-world data on metastatic castration-resistant prostate cancer (mCRPC) patients managed with AA+P in Canada. Herein, we report their patient-reported outcomes (PROs). METHODS: After a median followup of 67.1 weeks, 254 patients were enrolled across 39 sites. Functional Assessment of Cancer Therapy-Prostate (FACT-P), Montreal Cognitive Assessment (MoCA), Brief Pain Inventory-Short Form (BPI-SF), Brief Fatigue Inventory (BFI), and Current Health Satisfaction in Prostate Cancer (CHS-PCa) were evaluated at baseline, as well as at weeks 12, 24, 48, and 72 after AA+P initiation. Descriptive analysis was used with continuous variables. Changes from baseline were summarized using mean (standard deviation [SD]). RESULTS: At a median age of 76.6 (8.94), baseline FACT-P total score was 111.3 (19.56) with no significant change in their functional status observed from baseline over time. The median baseline MoCA score was 25.2 (4.52), yet subsequent assessments showed an absence of cognitive decline while under treatment. Similarly, no meaningful changes were detected in BPI, BFI, and CHS-PCa during the 72-week study period, thus suggesting that patients' PROs were well-maintained throughout AA+P treatment. Prostate-specific antigen (PSA) response with >50% decline was 66.4%. Safety profile was consistent with the known side effect of AA+P. CONCLUSIONS: COSMiC represents the largest Canadian mCRPC cohort treated with AA+P with real-world, prospective evaluation of PROs. This data demonstrated the maintenance in quality of life and cognitive status over the course of the study and underscores the importance of PRO use in this complex patient population.