Prioritization of Randomized Clinical Trial Questions for Children Hospitalized With Common Conditions: A Consensus Statement.

Importance: There is a lack of randomized clinical trial (RCT) data to guide many routine decisions in the care of children hospitalized for common conditions. A first step in addressing the shortage of RCTs for this population is to identify the most pressing RCT questions for children hospitalized with common conditions. Objective: To identify the most important and feasible RCT questions for children hospitalized with common conditions. Design, Setting, and Participants: For this consensus statement, a 3-stage modified Delphi process was used in a virtual conference series spanning January 1 to September 29, 2022. Forty-six individuals from 30 different institutions participated in the process. Stage 1 involved construction of RCT questions for the 10 most common pediatric conditions leading to hospitalization. Participants used condition-specific guidelines and reviews from a structured literature search to inform their development of RCT questions. During stage 2, RCT questions were refined and scored according to importance. Stage 3 incorporated public comment and feasibility with the prioritization of RCT questions. Main Outcomes and Measures: The main outcome was RCT questions framed in a PICO (population, intervention, control, and outcome) format and ranked according to importance and feasibility; score choices ranged from 1 to 9, with higher scores indicating greater importance and feasibility. Results: Forty-six individuals (38 who shared demographic data; 24 women [63%]) from 30 different institutions participated in our modified Delphi process. Participants included children's hospital (n = 14) and community hospital (n = 13) pediatricians, parents of hospitalized children (n = 4), other clinicians (n = 2), biostatisticians (n = 2), and other researchers (n = 11). The process yielded 62 unique RCT questions, most of which are pragmatic, comparing interventions in widespread use for which definitive effectiveness data are lacking. Overall scores for importance and feasibility of the RCT questions ranged from 1 to 9, with a median of 5 (IQR, 4-7). Six of the top 10 selected questions focused on determining optimal antibiotic regimens for 3 common infections (pneumonia, urinary tract infection, and cellulitis). Conclusions and Relevance: This consensus statementhas identified the most important and feasible RCT questions for children hospitalized with common conditions. This list of RCT questions can guide investigators and funders in conducting impactful trials to improve care and outcomes for hospitalized children.

Cultivating compassion in medicine: a toolkit for medical students to improve self-kindness and enhance clinical care.

BACKGROUND: Compassionate care lies at the foundation of good patient care and is a quality that patients and providers continue to value in the fast-paced setting of contemporary medicine. Compassion is often discussed superficially in medical school curricula, but the practical aspect of learning this skill is often not taught using a formal framework. In the present work, the authors present an 8-session curriculum with a mindfulness-based approach to compassion that addresses this need. It is hypothesized that students in this curriculum will improve in their levels of compassion based on validated scales. METHODS: The curriculum was delivered to fourth-year medical students at Renaissance School of Medicine at Stony Brook University who had just completed their clerkship year. It was developed as a customizable set of modules that could be delivered in various ways. The students were taught with evidence-based cognitive exercises followed by group discussions and written reflections based on compassion-focused thematic questions. All students completed a pre- and post-Self-Compassion Scale, Compassion Scale, and Toronto Mindfulness Scale. Students in this course were compared with students in different courses about non-clinical topics delivered at the same time. Wilcoxon Signed Rank tests and Mann Whitney U tests were used to assess potential associations between pre- and post-survey responses for the validated scales and subscales. RESULTS: 17 fourth-year medical students completed pre- and post-course tests, 11 participated in the compassion curriculum while 6 participated from the other courses. Before any of the courses began, all students performed similarly on the pre-test across all scales. The students in the compassion curriculum demonstrated a significant increase in their total Self-Compassion score by 8.7 [95% CI 4.3 to 13.2] points (p = 0.008), total Compassion score by 6.0 [95% CI 1.4 to 10.6] points (p = 0.012), and the curiosity component of the Toronto Mindfulness Scale by 4.4 [95% CI 1.0 to 7.7] points (p = 0.012). There was no statistically significant difference between pre- and post-tests among the non-compassion curriculum students in the aforementioned scales (p = 0.461, p = 0.144, p = 0.785, respectively). CONCLUSIONS: Our results indicate that the students in our course developed an enhanced ability to engage in self-compassion, to understand the shared human experience, and to be motivated to act to alleviate suffering. Regardless of a program's existing compassion education, this customizable model allows for easy integration into a medical student's crowded curriculum. Furthermore, although teaching compassion early and often in a clinician's training is desirable, our study that targeted fourth-year medical students suggests an additional benefit of rekindling the loss of compassion well described in a medical student's clinical years.

Incidence, characteristics, risk factors and outcomes of diabetic ketoacidosis in COVID-19 patients: Comparison with influenza and pre-pandemic data.

AIMS: This study characterized incidence, patient profiles, risk factors and outcomes of in-hospital diabetic ketoacidosis (DKA) in patients with COVID-19 compared with influenza and pre-pandemic data. METHODS: This study consisted of 13 383 hospitalized patients with COVID-19 (March 2020-July 2022), 19 165 hospitalized patients with influenza (January 2018-July 2022) and 35 000 randomly sampled hospitalized pre-pandemic patients (January 2017-December 2019) in Montefiore Health System, Bronx, NY, USA. Primary outcomes were incidence of in-hospital DKA, in-hospital mortality, and insulin use at 3 and 6 months post-infection. Risk factors for developing DKA were identified. RESULTS: The overall incidence of DKA in patients with COVID-19 and influenza, and pre-pandemic were 2.1%, 1.4% and 0.5%, respectively (p < .05 pairwise). Patients with COVID-19 with DKA had worse acute outcomes (p < .05) and higher incidence of new insulin treatment 3 and 6 months post-infection compared with patients with influenza with DKA (p < .05). The incidence of DKA in patients with COVID-19 was highest among patients with type 1 diabetes (12.8%), followed by patients with insulin-dependent type 2 diabetes (T2D; 5.2%), non-insulin dependent T2D (2.3%) and, lastly, patients without T2D (1.3%). Patients with COVID-19 with DKA had worse disease severity and higher mortality [odds ratio = 6.178 (4.428-8.590), p < .0001] compared with those without DKA. Type 1 diabetes, steroid therapy for COVID-19, COVID-19 status, black race and male gender were associated with increased risk of DKA. CONCLUSIONS: The incidence of DKA was higher in COVID-19 cohort compared to the influenza and pre-pandemic cohort. Patients with COVID-19 with DKA had worse outcomes compared with those without. Many COVID-19 survivors who developed DKA during hospitalization became insulin dependent. Identification of risk factors for DKA and new insulin-dependency could enable careful monitoring and timely intervention.

COVID-19 associated ketosis and diabetic ketoacidosis: A rapid review.

SARS-CoV-2 infection could disrupt the endocrine system directly or indirectly, which could result in endocrine dysfunction and glycaemic dysregulation, triggering transient or persistent diabetes mellitus. The literature on the complex relationship between COVID-19 and endocrine dysfunctions is still evolving and remains incompletely understood. Thus, we conducted a review on all literature to date involving COVID-19 associated ketosis or diabetic ketoacidosis (DKA). In total, 27 publications were included and analysed quantitatively and qualitatively. Studies included patients with DKA with existing or new onset diabetes. While the number of case and cohort studies was limited, DKA in the setting of COVID-19 seemed to increase risk of death, particularly in patients with new onset diabetes. Future studies with more specific variables and larger sample sizes are needed to draw better conclusions.

Characterisation of eight cattle with Swyer syndrome by whole-genome sequencing.

Swyer syndrome is where an individual has the karyotype of a typical male yet is phenotypically a female. The lack of a (functional) SRY gene located on the Y-chromosome is implicated in some cases of the Swyer syndrome, although many Swyer individuals with an apparently fully functional SRY gene have also been documented. The present study undertook whole genome sequence analyses of eight cattle with suspected Swyer syndrome and compared their genome to that of both a control male and female. Sequence analyses coupled with female phenotypes confirmed that all eight individuals had the 60,XY sex reversal Swyer syndrome. Seven of the eight Swyer syndrome individuals had a deletion on the Y chromosome encompassing the SRY gene (i.e., SRY-). The eighth individual had no obvious mutation in the SRY gene (SRY+) or indeed in any reported gene associated with sex reversal in mammals; a necropsy was performed on this individual. No testicles were detected during the necropsy. Histological examination of the reproductive tract revealed an immature uterine body and horns with inactive glandular tissue of normal histological appearance; both gonads were elongated, a characteristic of most reported cases of Swyer in mammals. The flanking sequence of 11 single nucleotide polymorphisms within 10 kb of the SRY gene are provided to help diagnose some cases of Swyer syndrome. These single nucleotide polymorphisms will not, however, detect all cases of Swyer syndrome since, as evidenced from the present study (and other studies), some individuals with the Swyer condition still contain the SRY gene (i.e., SRY+).

Motivation to Impact: Medical Student Volunteerism in the COVID 19 Pandemic.

Objective: Volunteerism represents an important mechanism to promote resilience, empathy, and general well-being in medical students, a group that stands to benefit. Medical students report feelings of fatigue, burnout, exhaustion, and stress that correlates with poor academic performance, and significant decline in empathy over the 3rd year of both MD and DO programs. Volunteer motivations have been shown to mediate participant well-being. The relationship between medical student volunteer motivations and specific outcomes during the COVID-19 pandemic has not been addressed. Methods: We characterized features of medical student volunteers during the COVID-19 pandemic in 2020, including volunteering motivation using the Volunteer Functions Inventory, the types of activities in which they participated, and the physical, psychosocial, and emotional outcomes they experienced following volunteering. Results: Altruistic and humanitarian values-centric motivation predicts positive volunteering outcomes including increased resilience, ability to deal with disappointment and loss, and ability to cope with the COVID-19 pandemic. Values-centric motivation also increases volunteer empathy independent of educational stage. Values-centric participants were more likely to select volunteering activities with patient contact, which promotes student empathy and resilience. Conversely, career-centric motivation does not predict positive outcomes. These students are more likely to engage in research-oriented activities. Conclusions: The efficacy of integrating volunteerism into medical school curricula may be limited by professional pressure that manifests as career-oriented motivation. We propose that practical integration should promote altruistic and humanitarian values-centric participant orientation to the volunteering process, which is associated with enhanced recruitment, preservation of empathy, and additional positive volunteering outcomes of interest.

De novo pyrimidine synthesis is a targetable vulnerability in IDH mutant glioma.

Mutations affecting isocitrate dehydrogenase (IDH) enzymes are prevalent in glioma, leukemia, and other cancers. Although mutant IDH inhibitors are effective against leukemia, they seem to be less active in aggressive glioma, underscoring the need for alternative treatment strategies. Through a chemical synthetic lethality screen, we discovered that IDH1-mutant glioma cells are hypersensitive to drugs targeting enzymes in the de novo pyrimidine nucleotide synthesis pathway, including dihydroorotate dehydrogenase (DHODH). We developed a genetically engineered mouse model of mutant IDH1-driven astrocytoma and used it and multiple patient-derived models to show that the brain-penetrant DHODH inhibitor BAY 2402234 displays monotherapy efficacy against IDH-mutant gliomas. Mechanistically, this reflects an obligate dependence of glioma cells on the de novo pyrimidine synthesis pathway and mutant IDH's ability to sensitize to DNA damage upon nucleotide pool imbalance. Our work outlines a tumor-selective, biomarker-guided therapeutic strategy that is poised for clinical translation.

The Economic Burden of Chromosome Translocations and the Benefits of Enhanced Screening for Cattle Breeding.

The cattle breeding industry, through both of its derivatives (dairy and beef), provides 81% of milk and 22% of meat required globally. If a breeding bull is sub-fertile, this impacts herd conception and birth rates, and it is generally accepted that having a proactive genetic screening programme can prevent further losses. Chromosome translocations are the leading genetic cause of infertility in livestock and, in cattle, this extends beyond the classical 1:29 to other Robertsonian translocations (RobTs) and to reciprocal translocations (RECTs). The incidence of both (collectively termed RTs) varies between breeds and herds; however, we estimate that RECTs are, most likely, at least twice as common as RobTs. The purpose of this study was to develop an industry economic model to estimate the financial impact of an RT event at the herd level. If we assume a conservative incidence rate of 0.4% for Rob1:29 with each one impacting the conception rate by 5%, we calculate that actively screening for and removing a Rob1:29 bull could benefit an impacted herd by GBP 2.3 million (approx. USD 2.8 million) over six years. A recently updated screening protocol developed in our lab for all RTs, however (with a projected combined incidence of 1.2%, impacting conception rates by 10%), could benefit an impacted herd by GBP 7.2 million (nearly USD 9 million) for each RT found. For an industry worth USD 827.4 billion (dairy) and USD 467.7 billion (beef), expanding knowledge on incidence and further dissection of the potential costs (financial and environmental) from RTs is essential to prevent further losses.

BRCA1/Trp53 heterozygosity and replication stress drive esophageal cancer development in a mouse model.

BRCA1 germline mutations are associated with an increased risk of breast and ovarian cancer. Recent findings of others suggest that BRCA1 mutation carriers also bear an increased risk of esophageal and gastric cancer. Here, we employ a Brca1/Trp53 mouse model to show that unresolved replication stress (RS) in BRCA1 heterozygous cells drives esophageal tumorigenesis in a model of the human equivalent. This model employs 4-nitroquinoline-1-oxide (4NQO) as an RS-inducing agent. Upon drinking 4NQO-containing water, Brca1 heterozygous mice formed squamous cell carcinomas of the distal esophagus and forestomach at a much higher frequency and speed (∼90 to 120 d) than did wild-type (WT) mice, which remained largely tumor free. Their esophageal tissue, but not that of WT control mice, revealed evidence of overt RS as reflected by intracellular CHK1 phosphorylation and 53BP1 staining. These Brca1 mutant tumors also revealed higher genome mutation rates than those of control animals; the mutational signature SBS4, which is associated with tobacco-induced tumorigenesis; and a loss of Brca1 heterozygosity (LOH). This uniquely accelerated Brca1 tumor model is also relevant to human esophageal squamous cell carcinoma, an often lethal tumor.

Procalcitonin, C-reactive protein, neutrophil gelatinase-associated lipocalin, resistin and the APTT waveform for the early diagnosis of serious bacterial infection and prediction of outcome in critically ill children.

OBJECTIVE: Bacterial Infections remains a leading cause of death in the Paediatric Intensive Care Unit (PICU). In this era of rising antimicrobial resistance, new tools are needed to guide antimicrobial use. The aim of this study was to investigate the accuracy of procalcitonin (PCT), neutrophil gelatinase-associated lipocalin (NGAL), resistin, activated partial thromboplastin time (aPTT) waveform and C-reactive protein (CRP) for the diagnosis of serious bacterial infection (SBI) in children on admission to PICU and their use as prognostic indicators. SETTING: A regional PICU in the United Kingdom. PATIENTS: Consecutive PICU admissions between October 2010 and June 2012. MEASUREMENTS: Blood samples were collected daily for biomarker measurement. The primary outcome measure was performance of study biomarkers for diagnosis of SBI on admission to PICU based on clinical, radiological and microbiological criteria. Secondary outcomes included durations of PICU stay and invasive ventilation and 28-day mortality. Patients were followed up to day 28 post-admission. MAIN RESULTS: A total of 657 patients were included in the study. 92 patients (14%) fulfilled criteria for SBI. 28-day mortality was 2.6% (17/657), but 8.7% (8/92) for patients with SBI. The combination of PCT, resistin, plasma NGAL and CRP resulted in the greatest net reclassification improvement compared to CRP alone (0.69, p<0.005) with 10.5% reduction in correct classification of patients with SBI (p 0.52) but a 78% improvement in correct classification of patients without events (p <0.005). A statistical model of prolonged duration of PICU stay found log-transformed maximum values of biomarkers performed better than first recorded biomarkers. The final model included maximum values of CRP, plasma NGAL, lymphocyte and platelet count (AUC 79%, 95% CI 73.7% to 84.2%). Longitudinal profiles of biomarkers showed PCT levels to decrease most rapidly following admission SBI. CONCLUSION: Combinations of biomarkers, including PCT, may improve accurate and timely identification of SBI on admission to PICU.

Rapid Multi-Hybridisation FISH Screening for Balanced Porcine Reciprocal Translocations Suggests a Much Higher Abnormality Rate Than Previously Appreciated.

With demand rising, pigs are the world's leading source of meat protein; however significant economic loss and environmental damage can be incurred if boars used for artificial insemination (AI) are hypoprolific (sub-fertile). Growing evidence suggests that semen analysis is an unreliable tool for diagnosing hypoprolificacy, with litter size and farrowing rate being more applicable. Once such data are available, however, any affected boar will have been in service for some time, with significant financial and environmental losses incurred. Reciprocal translocations (RTs) are the leading cause of porcine hypoprolificacy, reportedly present in 0.47% of AI boars. Traditional standard karyotyping, however, relies on animal specific expertise and does not detect more subtle (cryptic) translocations. Previously, we reported development of a multiple hybridisation fluorescence in situ hybridisation (FISH) strategy; here, we report on its use in 1641 AI boars. A total of 15 different RTs were identified in 69 boars, with four further animals XX/XY chimeric. Therefore, 4.5% had a chromosome abnormality (4.2% with an RT), a 0.88% incidence. Revisiting cases with both karyotype and FISH information, we reanalysed captured images, asking whether the translocation was detectable by karyotyping alone. The results suggest that chromosome translocations in boars may be significantly under-reported, thereby highlighting the need for pre-emptive screening by this method before a boar enters a breeding programme.

Title NMR-based metabolic profiling provides diagnostic and prognostic information in critically ill children with suspected infection.

Sepsis, defined as life-threatening organ dysfunction caused by infection is difficult to distinguish clinically from infection or post-operative inflammation. We hypothesized that in a heterogeneous group of critically ill children, there would be different metabolic profiles between post-operative inflammation, bacterial and viral infection and infection with or without organ dysfunction. 1D 1H nuclear magnetic resonance spectra were acquired in plasma samples from critically ill children. We included children with bacterial (n = 25) and viral infection (n = 30) and controls (n = 58) (elective cardiac surgery without infection). Principal component analysis was used for data exploration and partial least squares discriminant analysis models for the differences between groups. Area under receiver operating characteristic curve (AUC) values were used to evaluate the models. Univariate analysis demonstrated differences between controls and bacterial and viral infection. There was excellent discrimination between bacterial and control (AUC = 0.94), and viral and control (AUC = 0.83), with slightly more modest discrimination between bacterial and viral (AUC = 0.78). There was modest discrimination (AUC = 0.73) between sepsis with organ dysfunction and infection with no organ dysfunction. In critically ill children, NMR metabolomics differentiates well between those with a post-operative inflammation but no infection, and those with infection (bacterial and viral), and between sepsis and infection.

Identifying critically ill children at high risk of acute kidney injury and renal replacement therapy.

Acute kidney injury (AKI), a common complication in paediatric intensive care units (PICU), is associated with increased morbidity and mortality. In this single centre, prospective, observational cohort study, neutrophil gelatinase-associated lipocalin in urine (uNGAL) and plasma (pNGAL) and renal angina index (RAI), and combinations of these markers, were assessed for their ability to predict severe (stage 2 or 3) AKI in children and young people admitted to PICU. In PICU children and young people had initial and serial uNGAL and pNGAL measurements, RAI calculation on day 1, and collection of clinical data, including serum creatinine measurements. Primary outcomes were severe AKI and renal replacement therapy (RRT). Secondary outcomes were length of stay, hospital acquired infection and mortality. The area under the Receiver Operating Characteristic (ROC) curves and Youden index was used to determine biomarker performance and identify optimum cut-off values. Of 657 children recruited, 104 met criteria for severe AKI (15∙8%) and 47 (7∙2%) required RRT. Severe AKI was associated with increased length of stay, hospital acquired infection, and mortality. The area under the curve (AUC) for severe AKI prediction for Day 1 uNGAL, Day 1 pNGAL and RAI were 0.75 (95% Confidence Interval [CI] 0∙69, 0∙81), 0∙64 (95% CI 0∙56, 0∙72), and 0.73 (95% CI 0∙65, 0∙80) respectively. The optimal combination of measures was RAI and day 1 uNGAL, giving an AUC of 0∙80 for severe AKI prediction (95% CI 0∙71, 0∙88). In this heterogenous PICU cohort, urine or plasma NGAL in isolation had poorer prediction accuracy for severe AKI than in previously reported homogeneous populations. However, when combined together with RAI, they produced good prediction for severe AKI.

Effects of polysubstance exposure on neonatal outcomes for infants with intrauterine opioid exposure.

OBJECTIVE: Quantify the effect of prenatal polysubstance exposure on neonatal outcomes compared to methadone exposure alone. STUDY DESIGN: This retrospective cohort study compared infants with methadone-only exposure to methadone with additional psychoactive substances. Outcomes included time to maximum Finnegan scores, proportion requiring scheduled morphine, and length of stay (LOS). RESULTS: We identified 323 subjects. The median time to maximum Finnegan score was 38.0 h with 94% peaking within 96 h. Forty-five percent of methadone-only infants were started on scheduled morphine compared to 54% of polysubstance infants (p = 0.10). LOS for polysubstance-exposed infants was 1.30 times longer than infants with methadone-only exposure (95% confidence interval: 1.05, 1.60). CONCLUSIONS: Exposure to methadone with additional psychoactive substances is associated with longer LOS, but not postnatal morphine use or peak withdrawal symptoms. Most infants experience peak withdrawal symptoms within 4 days and may not benefit from longer observation.

A new Approach for Accurate Detection of Chromosome Rearrangements That Affect Fertility in Cattle.

Globally, cattle production has more than doubled since the 1960s, with widespread use of artificial insemination (AI) and an emphasis on a small pool of high genetic merit animals. Selecting AI bulls with optimal fertility is, therefore, vital, as impaired fertility reduces genetic gains and production, resulting in heavy financial and environmental losses. Chromosome translocations, particularly the 1;29 Robertsonian translocation, are a common cause of reduced fertility; however, reciprocal translocations are significantly underreported due to the difficulties inherent in analysing cattle chromosomes. Based on our porcine work, we have developed an approach for the unambiguous detection of Robertsonian and reciprocal translocations, using a multiple-hybridization probe detection strategy. We applied this method on the chromosomes of 39 bulls, detecting heterozygous and homozygous 1;29 translocations and a 12;23 reciprocal translocation in a total of seven animals. Previously, karyotype analysis was the only method of diagnosing chromosomal rearrangements in cattle, and was time-consuming and error-prone. With calving rates of only 50-60%, it is vital to reduce further fertility loss in order to maximise productivity. The approach developed here identifies abnormalities that DNA sequencing will not, and has the potential to lead to long-term gains, delivering meat and milk products in a more cost-effective and environmentally-responsible manner to a growing population.

Cost-effectiveness of Imaging Protocols for Suspected Appendicitis.

BACKGROUND: Inaccurate diagnosis of appendicitis leads to increased costs and morbidity. Ultrasound costs less than computed tomography (CT) or MRI but has lower sensitivity and may not visualize the appendix. METHODS: We conducted a cost-effectiveness analysis using a decision-analytic model of 10 imaging strategies for suspected appendicitis in a hypothetical cohort of patients: no imaging with discharge or surgery; CT only; MRI only; or staged approach with CT or MRI after 1) negative ultrasound result or ultrasound without appendix visualization, 2) ultrasound without appendix visualization, or 3) ultrasound without appendix visualization but with secondary signs of inflammation. Inputs were derived from published literature and secondary data (quality-of-life and cost data). Sensitivity analyses varied risk of appendicitis and proportion of visualized ultrasound. Outcomes were effectiveness (quality-adjusted life-years [QALYs]), total direct medical costs, and cost-effectiveness (cost per QALY gained). RESULTS: The most cost-effective strategy for patients at moderate risk for appendicitis is initial ultrasound, followed by CT if the appendix is not visualized but secondary signs are present (cost of $4815.03; effectiveness of 0.99694 QALYs). Other strategies were well above standard willingness-to-pay thresholds or were more costly and less effective. Cost-effectiveness was sensitive to patients' risk of appendicitis but not the proportion of visualized appendices. CONCLUSIONS: Tailored approaches to imaging based on patients' risk of appendicitis are the most cost-effective. Imaging is not cost-effective in patients with a probability <16% or >95%. For moderate-risk patients, ultrasound without secondary signs of inflammation is sufficient even without appendix visualization.

The KDM5A/RBP2 histone demethylase represses NOTCH signaling to sustain neuroendocrine differentiation and promote small cell lung cancer tumorigenesis.

More than 90% of small cell lung cancers (SCLCs) harbor loss-of-function mutations in the tumor suppressor gene RB1 The canonical function of the RB1 gene product, pRB, is to repress the E2F transcription factor family, but pRB also functions to regulate cellular differentiation in part through its binding to the histone demethylase KDM5A (also known as RBP2 or JARID1A). We show that KDM5A promotes SCLC proliferation and SCLC's neuroendocrine differentiation phenotype in part by sustaining expression of the neuroendocrine transcription factor ASCL1. Mechanistically, we found that KDM5A sustains ASCL1 levels and neuroendocrine differentiation by repressing NOTCH2 and NOTCH target genes. To test the role of KDM5A in SCLC tumorigenesis in vivo, we developed a CRISPR/Cas9-based mouse model of SCLC by delivering an adenovirus (or an adeno-associated virus [AAV]) that expresses Cre recombinase and sgRNAs targeting Rb1, Tp53, and Rbl2 into the lungs of Lox-Stop-Lox Cas9 mice. Coinclusion of a KDM5A sgRNA decreased SCLC tumorigenesis and metastasis, and the SCLCs that formed despite the absence of KDM5A had higher NOTCH activity compared to KDM5A+/+ SCLCs. This work establishes a role for KDM5A in SCLC tumorigenesis and suggests that KDM5 inhibitors should be explored as treatments for SCLC.

HIF-independent synthetic lethality between CDK4/6 inhibition and VHL loss across species.

Inactivation of the VHL tumor suppressor gene is the signature initiating event in clear cell renal cell carcinoma (ccRCC), the most common form of kidney cancer, and causes the accumulation of hypoxia-inducible factor 2α (HIF-2α). HIF-2α inhibitors are effective in some ccRCC cases, but both de novo and acquired resistance have been observed in the laboratory and in the clinic. Here, we identified synthetic lethality between decreased activity of cyclin-dependent kinases 4 and 6 (CDK4/6) and VHL inactivation in two species (human and Drosophila) and across diverse human ccRCC cell lines in culture and xenografts. Although HIF-2α transcriptionally induced the CDK4/6 partner cyclin D1, HIF-2α was not required for the increased CDK4/6 requirement of VHL-/- ccRCC cells. Accordingly, the antiproliferative effects of CDK4/6 inhibition were synergistic with HIF-2α inhibition in HIF-2α-dependent VHL-/- ccRCC cells and not antagonistic with HIF-2α inhibition in HIF-2α-independent cells. These findings support testing CDK4/6 inhibitors as treatments for ccRCC, alone and in combination with HIF-2α inhibitors.

PD-L1 Expression and Clinical Outcomes to Cabozantinib, Everolimus, and Sunitinib in Patients with Metastatic Renal Cell Carcinoma: Analysis of the Randomized Clinical Trials METEOR and CABOSUN.

PURPOSE: Programmed death-ligand 1 (PD-L1) status by IHC is prognostic in metastatic renal cell carcinoma (mRCC), and its role as a potential predictive biomarker is under investigation. Using tumor tissue from the METEOR (NCT01865747) and CABOSUN (NCT01835158) clinical trials, we explored whether PD-L1 expression and the extent of the immune cell infiltrate can serve as prognostic and/or predictive biomarkers for cabozantinib and other targeted agents. EXPERIMENTAL DESIGN: IHC double staining for PD-L1 and CD45/CD163 (immune cell markers) was performed on tumor tissue from METEOR (n = 306) and CABOSUN (n = 110) clinical trials. Immune cell density and MET expression levels were also analyzed. Our primary aim was to correlate progression-free survival (PFS) by independent central review with PD-L1 status in patients treated with cabozantinib, everolimus (METEOR), or sunitinib (CABOSUN). Overall survival (OS) was also interrogated. RESULTS: Tumor cell (TC) PD-L1 expression (≥1% cutoff) was detected in 29% and 23% of tumors from patients in the METEOR and CABOSUN trials, respectively. On univariate analysis, patients with PD-L1-positive TC had poorer PFS and OS than patients with PD-L1-negative TC on both trials, independent of therapy. On multivariable analysis and when combining the two trials, the association between TC PD-L1 expression and OS was statistically significant for all patients (P = 0.034) and for patients treated with cabozantinib only (P = 0.038). Cabozantinib was associated with improved PFS (HR < 0.70) and OS (HR < 0.85) compared with everolimus and sunitinib irrespective of PD-L1 expression. CONCLUSIONS: Higher PD-L1 expression results in worse clinical outcomes in mRCC treated with targeted therapy. Furthermore, PD-L1 expression is not predictive of response to cabozantinib therapy.