Pathway level subtyping identifies a slow-cycling biological phenotype associated with poor clinical outcomes in colorectal cancer

Molecular stratification using gene-level transcriptional data has identified subtypes with distinctive genotypic and phenotypic traits, as exemplified by the consensus molecular subtypes (CMS) in colorectal cancer (CRC). Here, rather than gene-level data, we make use of gene ontology and biological activation state information for initial molecular class discovery. In doing so, we defined three pathway-derived subtypes (PDS) in CRC: PDS1 tumors, which are canonical/LGR5+ stem-rich, highly proliferative and display good prognosis; PDS2 tumors, which are regenerative/ANXA1+ stem-rich, with elevated stromal and immune tumor microenvironmental lineages; and PDS3 tumors, which represent a previously overlooked slow-cycling subset of tumors within CMS2 with reduced stem populations and increased differentiated lineages, particularly enterocytes and enteroendocrine cells, yet display the worst prognosis in locally advanced disease. These PDS3 phenotypic traits are evident across numerous bulk and single-cell datasets, and demark a series of subtle biological states that are currently under-represented in pre-clinical models and are not identified using existing subtyping classifiers.

Characterizing Neutrophil Subtypes in Cancer Using scRNA Sequencing Demonstrates the Importance of IL1β/CXCR2 Axis in Generation of Metastasis-specific Neutrophils

Neutrophils are a highly heterogeneous cellular population. However, a thorough examination of the different transcriptional neutrophil states between health and malignancy has not been performed. We utilized single-cell RNA sequencing of human and murine datasets, both publicly available and independently generated, to identify neutrophil transcriptomic subtypes and developmental lineages in health and malignancy. Datasets of lung, breast, and colorectal cancer were integrated to establish and validate neutrophil gene signatures. Pseudotime analysis was used to identify genes driving neutrophil development from health to cancer. Finally, ligand-receptor interactions and signaling pathways between neutrophils and other immune cell populations in primary colorectal cancer and metastatic colorectal cancer were investigated. We define two main neutrophil subtypes in primary tumors: an activated subtype sharing the transcriptomic signatures of healthy neutrophils; and a tumor-specific subtype. This signature is conserved in murine and human cancer, across different tumor types. In colorectal cancer metastases, neutrophils are more heterogeneous, exhibiting additional transcriptomic subtypes. Pseudotime analysis implicates IL1β/CXCL8/CXCR2 axis in the progression of neutrophils from health to cancer and metastasis, with effects on T-cell effector function. Functional analysis of neutrophil-tumoroid cocultures and T-cell proliferation assays using orthotopic metastatic mouse models lacking Cxcr2 in neutrophils support our transcriptional analysis. We propose that the emergence of metastatic-specific neutrophil subtypes is driven by the IL1β/CXCL8/CXCR2 axis, with the evolution of different transcriptomic signals that impair T-cell function at the metastatic site. Thus, a better understanding of neutrophil transcriptomic programming could optimize immunotherapeutic interventions into early and late interventions, targeting different neutrophil states.

SIGNIFICANCE

We identify two recurring neutrophil populations and demonstrate their staged evolution from health to malignancy through the IL1β/CXCL8/CXCR2 axis, allowing for immunotherapeutic neutrophil-targeting approaches to counteract immunosuppressive subtypes that emerge in metastasis.

KRAS allelic imbalance drives tumour initiation yet suppresses metastasis in colorectal cancer in vivo

Oncogenic KRAS mutations are well-described functionally and are known to drive tumorigenesis. Recent reports describe a significant prevalence of KRAS allelic imbalances or gene dosage changes in human cancers, including loss of the wild-type allele in KRAS mutant cancers. However, the role of wild-type KRAS in tumorigenesis and therapeutic response remains elusive. We report an in vivo murine model of colorectal cancer featuring deletion of wild-type Kras in the context of oncogenic Kras. Deletion of wild-type Kras exacerbates oncogenic KRAS signalling through MAPK and thus drives tumour initiation. Absence of wild-type Kras potentiates the oncogenic effect of KRASG12D, while incidentally inducing sensitivity to inhibition of MEK1/2. Importantly, loss of the wild-type allele in aggressive models of KRASG12D-driven CRC significantly alters tumour progression, and suppresses metastasis through modulation of the immune microenvironment. This study highlights the critical role for wild-type Kras upon tumour initiation, progression and therapeutic response in Kras mutant CRC.

Pain Frequency and Health Care Utilization Patterns in Women with Sickle Cell Disease Experiencing Menstruation-Associated Pain Crises

Background: Pain crises in sickle cell disease (SCD) lead to high rates of health care utilization. Historically, women have reported higher pain burdens than men, with recent studies showing a temporal association between pain crisis and menstruation. However, health care utilization patterns of SCD women with menstruation-associated pain crises have not been reported. We studied the frequency, severity, and health care utilization of menstruation-associated pain crises in SCD women. Materials and Methods: A multinational, cross-sectional cohort study of the SCD phenotype was executed using a validated questionnaire and medical chart review from the Consortium for the Advancement of Sickle Cell Research (CASiRe) cohort. Total number of pain crises, emergency room/day hospital visits, and hospitalizations were collected from a subcohort of 178 SCD women within the past 6 months and previous year. Results: Thirty-nine percent of women reported menstruation-associated pain crises in their lifetime. These women were significantly more likely to be hospitalized compared with those who did not (mean 1.70 vs. 0.67, p = 0.0005). Women reporting menstruation-associated pain crises in the past 6 months also experienced increased hospitalizations compared with those who did not (mean 1.71 vs. 0.75, p = 0.0016). Forty percent of women reported at least four menstruation-associated pain crises in the past 6 months. Conclusions: Nearly 40% of SCD women have menstruation-associated pain crises. Menstruation-associated pain crises are associated with high pain burden and increased rates of hospitalization. Strategies are needed to address health care disparities within gynecologic care in SCD.

Return visit rates after an emergency department discharge for children with sickle cell pain episodes

BACKGROUND

High return visit rates after hospitalization for people with sickle cell disease (SCD) have been previously established. Due to a lack of multicenter emergency department (ED) return visit rate data, the return visit rate following ED discharge for pediatric SCD pain treatment is currently unknown.

PROCEDURE

A seven-site retrospective cohort study of discharged ED visits for pain by children with SCD was conducted using the Pediatric Emergency Care Applied Research Network Registry. Visits between January 2017 and November 2021 were identified using previously validated criteria. The primary outcome was the 14-day return visit rate, with 3- and 7-day rates also calculated. Modified Poisson regression was used to analyze associations for age, sex, initial hospitalization rate, and a visit during the COVID-19 pandemic with return visit rates.

RESULTS

Of 2548 eligible ED visits, approximately 52% were patients less than 12 years old, 50% were female, and over 95% were non-Hispanic Black. The overall 14-day return visit rate was 29.1% (95% confidence interval [CI]: 27.4%-30.9%; site range 22.7%-31.7%); the 7- and 3-day return visit rates were 23.0% (95% CI: 21.3%-24.6%) and 16.7% (95% CI: 15.3%-18.2%), respectively. Younger children had slightly lower 14-day return visit rates (27.3% vs. 31.1%); there were no associations for site hospitalization rate, sex, and a visit occurring during the pandemic with 14-day returns.

CONCLUSION

Nearly 30% of ED discharged visits after SCD pain treatment had a return visit within 14 days. Increased efforts are needed to identify causes for high ED return visit rates and ensure optimal ED and post-ED care.

Driver gene combinations dictate cutaneous squamous cell carcinoma disease continuum progression

The molecular basis of disease progression from UV-induced precancerous actinic keratosis (AK) to malignant invasive cutaneous squamous cell carcinoma (cSCC) and potentially lethal metastatic disease remains unclear. DNA sequencing studies have revealed a massive mutational burden but have yet to illuminate mechanisms of disease progression. Here we perform RNAseq transcriptomic profiling of 110 patient samples representing normal sun-exposed skin, AK, primary and metastatic cSCC and reveal a disease continuum from a differentiated to a progenitor-like state. This is accompanied by the orchestrated suppression of master regulators of epidermal differentiation, dynamic modulation of the epidermal differentiation complex, remodelling of the immune landscape and an increase in the preponderance of tumour specific keratinocytes. Comparative systems analysis of human cSCC coupled with the generation of genetically engineered murine models reveal that combinatorial sequential inactivation of the tumour suppressor genes Tgfbr2, Trp53, and Notch1 coupled with activation of Ras signalling progressively drives cSCC progression along a differentiated to progenitor axis. Taken together we provide a comprehensive map of the cSCC disease continuum and reveal potentially actionable events that promote and accompany disease progression.

The evolution of the COVID-19 pandemic in paediatric patients with sickle cell disease: From Alpha to Omicron

We compare the impact of SARS-CoV-2 variants on healthcare utilization and clinical presentation in paediatric patients with sickle cell disease (SCD). One hundred and ninety-one unique patients with SCD and positive SARS-CoV-2 polymerase chain reactions were identified between March 2020 and January 2022. Hospitalizations, which accounted for 42% (N = 81) of cases, were highest during the Delta dominant era (48%) and lowest during Omicron (36%) (p = 0.285). The most common SCD-related complication was vaso-occlusive pain (37%, N = 71), which accounted for 51% of all hospital admissions (N = 41), and acute chest was highest in the Alpha variant era (N = 15). Overall, COVID-19 remained mild in clinical severity within most paediatric SCD patients.

Metabolic profiling stratifies colorectal cancer and reveals adenosylhomocysteinase as a therapeutic target

The genomic landscape of colorectal cancer (CRC) is shaped by inactivating mutations in tumour suppressors such as APC, and oncogenic mutations such as mutant KRAS. Here we used genetically engineered mouse models, and multimodal mass spectrometry-based metabolomics to study the impact of common genetic drivers of CRC on the metabolic landscape of the intestine. We show that untargeted metabolic profiling can be applied to stratify intestinal tissues according to underlying genetic alterations, and use mass spectrometry imaging to identify tumour, stromal and normal adjacent tissues. By identifying ions that drive variation between normal and transformed tissues, we found dysregulation of the methionine cycle to be a hallmark of APC-deficient CRC. Loss of Apc in the mouse intestine was found to be sufficient to drive expression of one of its enzymes, adenosylhomocysteinase (AHCY), which was also found to be transcriptionally upregulated in human CRC. Targeting of AHCY function impaired growth of APC-deficient organoids in vitro, and prevented the characteristic hyperproliferative/crypt progenitor phenotype driven by acute deletion of Apc in vivo, even in the context of mutant Kras. Finally, pharmacological inhibition of AHCY reduced intestinal tumour burden in ApcMin/+ mice indicating its potential as a metabolic drug target in CRC.

Therapeutic targeting of tumour myeloid cells

Myeloid cells are pivotal within the immunosuppressive tumour microenvironment. The accumulation of tumour-modified myeloid cells derived from monocytes or neutrophils - termed 'myeloid-derived suppressor cells' - and tumour-associated macrophages is associated with poor outcome and resistance to treatments such as chemotherapy and immune checkpoint inhibitors. Unfortunately, there has been little success in large-scale clinical trials of myeloid cell modulators, and only a few distinct strategies have been used to target suppressive myeloid cells clinically so far. Preclinical and translational studies have now elucidated specific functions for different myeloid cell subpopulations within the tumour microenvironment, revealing context-specific roles of different myeloid cell populations in disease progression and influencing response to therapy. To improve the success of myeloid cell-targeted therapies, it will be important to target tumour types and patient subsets in which myeloid cells represent the dominant driver of therapy resistance, as well as to determine the most efficacious treatment regimens and combination partners. This Review discusses what we can learn from work with the first generation of myeloid modulators and highlights recent developments in modelling context-specific roles for different myeloid cell subtypes, which can ultimately inform how to drive more successful clinical trials.

MmCMS: mouse models' consensus molecular subtypes of colorectal cancer

BACKGROUND

Colorectal cancer (CRC) primary tumours are molecularly classified into four consensus molecular subtypes (CMS1-4). Genetically engineered mouse models aim to faithfully mimic the complexity of human cancers and, when appropriately aligned, represent ideal pre-clinical systems to test new drug treatments. Despite its importance, dual-species classification has been limited by the lack of a reliable approach. Here we utilise, develop and test a set of options for human-to-mouse CMS classifications of CRC tissue.

METHODS

Using transcriptional data from established collections of CRC tumours, including human (TCGA cohort; n = 577) and mouse (n = 57 across n = 8 genotypes) tumours with combinations of random forest and nearest template prediction algorithms, alongside gene ontology collections, we comprehensively assess the performance of a suite of new dual-species classifiers.

RESULTS

We developed three approaches: MmCMS-A; a gene-level classifier, MmCMS-B; an ontology-level approach and MmCMS-C; a combined pathway system encompassing multiple biological and histological signalling cascades. Although all options could identify tumours associated with stromal-rich CMS4-like biology, MmCMS-A was unable to accurately classify the biology underpinning epithelial-like subtypes (CMS2/3) in mouse tumours.

CONCLUSIONS

When applying human-based transcriptional classifiers to mouse tumour data, a pathway-level classifier, rather than an individual gene-level system, is optimal. Our R package enables researchers to select suitable mouse models of human CRC subtype for their experimental testing.

Consensus definition of essential, optimal, and suggested components of a pediatric sickle cell disease center

Sickle cell disease (SCD) requires coordinated, specialized medical care for optimal outcomes. There are no United States (US) guidelines that define a pediatric comprehensive SCD program. We report a modified Delphi consensus-seeking process to determine essential, optimal, and suggested elements of a comprehensive pediatric SCD center. Nineteen pediatric SCD specialists participated from the US. Consensus was predefined as 2/3 agreement on each element's categorization. Twenty-six elements were considered essential (required for guideline-based SCD care), 10 were optimal (recommended but not required), and five were suggested. This work lays the foundation for a formal recognition process of pediatric comprehensive SCD centers.

Clinical outcomes of children and adolescents with sickle cell disease and COVID-19 infection: A year in review at a metropolitan tertiary pediatric hospital

Background

COVID-19 was declared a global pandemic in March 2020. Early reports were primarily in adults, and sickle cell disease (SCD) was classified as a risk factor for severe COVID-19 disease. However, there are a limited number of primarily multi-center studies reporting on the clinical course of pediatric patients with SCD and COVID-19.

Methods

We conducted an observational study of all patients with SCD diagnosed with COVID-19 at our institution between March 31, 2020, and February 12, 2021. Demographic and clinical characteristics of this group were collected by retrospective chart review.

Results

A total of 55 patients were studied, including 38 children and 17 adolescents. Demographics, acute COVID-19 clinical presentation, respiratory support, laboratory findings, healthcare utilization, and SCD modifying therapies were comparable between the children and adolescents. Seventy-three percent (N = 40) of all patients required emergency department care or hospitalization. While 47% (N = 26) were hospitalized, only 5% (N = 3) of all patients required intensive care unit admission. Patients frequently had concurrent vaso-occlusive pain crisis (VOC) (N = 17, 43%) and acute chest syndrome (ACS) (N = 14, 35%). Those with ACS or an oxygen requirement had significantly higher white blood cell count, lower nadir hemoglobin, and higher D-dimers, supporting a pro-inflammatory and coagulopathic picture. Non-hospitalized patients were more likely to be on hydroxyurea than hospitalized patients (79 vs. 50%, p = 0.023).

Conclusion

Children and adolescent patients with SCD and acute COVID-19 often present with ACS and VOC pain requiring hospital-level care. Hydroxyurea treatment appears to be protective. We observed no mortality despite variable morbidity.

Epithelial TGFβ engages growth-factor signalling to circumvent apoptosis and drive intestinal tumourigenesis with aggressive features

The pro-tumourigenic role of epithelial TGFβ signalling in colorectal cancer (CRC) is controversial. Here, we identify a cohort of born to be bad early-stage (T1) colorectal tumours, with aggressive features and a propensity to disseminate early, that are characterised by high epithelial cell-intrinsic TGFβ signalling. In the presence of concurrent Apc and Kras mutations, activation of epithelial TGFβ signalling rampantly accelerates tumourigenesis and share transcriptional signatures with those of the born to be bad T1 human tumours and predicts recurrence in stage II CRC. Mechanistically, epithelial TGFβ signalling induces a growth-promoting EGFR-signalling module that synergises with mutant APC and KRAS to drive MAPK signalling that re-sensitise tumour cells to MEK and/or EGFR inhibitors. Together, we identify epithelial TGFβ signalling both as a determinant of early dissemination and a potential therapeutic vulnerability of CRC's with born to be bad traits.

Activation of innate-adaptive immune machinery by poly(I:C) exposes a therapeutic vulnerability to prevent relapse in stroma-rich colon cancer

OBJECTIVE

Stroma-rich tumours represent a poor prognostic subtype in stage II/III colon cancer (CC), with high relapse rates and limited response to standard adjuvant chemotherapy.

DESIGN

To address the lack of efficacious therapeutic options for patients with stroma-rich CC, we stratified our human tumour cohorts according to stromal content, enabling identification of the biology underpinning relapse and potential therapeutic vulnerabilities specifically within stroma-rich tumours that could be exploited clinically. Following human tumour-based discovery and independent clinical validation, we use a series of in vitro and stroma-rich in vivo models to test and validate the therapeutic potential of elevating the biology associated with reduced relapse in human tumours.

RESULTS

By performing our analyses specifically within the stroma-rich/high-fibroblast (HiFi) subtype of CC, we identify and validate the clinical value of a HiFi-specific prognostic signature (HPS), which stratifies tumours based on STAT1-related signalling (High-HPS v Low-HPS=HR 0.093, CI 0.019 to 0.466). Using in silico, in vitro and in vivo models, we demonstrate that the HPS is associated with antigen processing and presentation within discrete immune lineages in stroma-rich CC, downstream of double-stranded RNA and viral response signalling. Treatment with the TLR3 agonist poly(I:C) elevated the HPS signalling and antigen processing phenotype across in vitro and in vivo models. In an in vivo model of stroma-rich CC, poly(I:C) treatment significantly increased systemic cytotoxic T cell activity (p<0.05) and reduced liver metastases (p<0.0002).

CONCLUSION

This study reveals new biological insight that offers a novel therapeutic option to reduce relapse rates in patients with the worst prognosis CC.

Dynamic and adaptive cancer stem cell population admixture in colorectal neoplasia

Intestinal homeostasis is underpinned by LGR5+ve crypt-base columnar stem cells (CBCs), but following injury, dedifferentiation results in the emergence of LGR5-ve regenerative stem cell populations (RSCs), characterized by fetal transcriptional profiles. Neoplasia hijacks regenerative signaling, so we assessed the distribution of CBCs and RSCs in mouse and human intestinal tumors. Using combined molecular-morphological analysis, we demonstrate variable expression of stem cell markers across a range of lesions. The degree of CBC-RSC admixture was associated with both epithelial mutation and microenvironmental signaling disruption and could be mapped across disease molecular subtypes. The CBC-RSC equilibrium was adaptive, with a dynamic response to acute selective pressure, and adaptability was associated with chemoresistance. We propose a fitness landscape model where individual tumors have equilibrated stem cell population distributions along a CBC-RSC phenotypic axis. Cellular plasticity is represented by position shift along this axis and is influenced by cell-intrinsic, extrinsic, and therapeutic selective pressures.

Aberrant Expression and Subcellular Localization of ECT2 Drives Colorectal Cancer Progression and Growth

ECT2 is an activator of RHO GTPases that is essential for cytokinesis. In addition, ECT2 was identified as an oncoprotein when expressed ectopically in NIH/3T3 fibroblasts. However, oncogenic activation of ECT2 resulted from N-terminal truncation, and such truncated ECT2 proteins have not been found in patients with cancer. In this study, we observed elevated expression of full-length ECT2 protein in preneoplastic colon adenomas, driven by increased ECT2 mRNA abundance and associated with APC tumor-suppressor loss. Elevated ECT2 levels were detected in the cytoplasm and nucleus of colorectal cancer tissue, suggesting cytoplasmic mislocalization as one mechanism of early oncogenic ECT2 activation. Importantly, elevated nuclear ECT2 correlated with poorly differentiated tumors, and a low cytoplasmic:nuclear ratio of ECT2 protein correlated with poor patient survival, suggesting that nuclear and cytoplasmic ECT2 play distinct roles in colorectal cancer. Depletion of ECT2 reduced anchorage-independent cancer cell growth and invasion independent of its function in cytokinesis, and loss of Ect2 extended survival in a Kras G12D Apc-null colon cancer mouse model. Expression of ECT2 variants with impaired nuclear localization or guanine nucleotide exchange catalytic activity failed to restore cancer cell growth or invasion, indicating that active, nuclear ECT2 is required to support tumor progression. Nuclear ECT2 promoted ribosomal DNA transcription and ribosome biogenesis in colorectal cancer. These results support a driver role for both cytoplasmic and nuclear ECT2 overexpression in colorectal cancer and emphasize the critical role of precise subcellular localization in dictating ECT2 function in neoplastic cells. SIGNIFICANCE: ECT2 overexpression and mislocalization support its role as a driver in colon cancer that is independent from its function in normal cell cytokinesis.

Global geographic differences in healthcare utilization for sickle cell disease pain crises in the CASiRe cohort

BACKGROUND

Sickle cell disease (SCD) is characterized by frequent, unpredictable pain episodes and other vaso-occlusive crises (VOCs) leading to significant healthcare utilization. VOC frequency is often an endpoint in clinical trials investigating novel therapies for this devastating disease.

PROCEDURE

The Consortium for the Advancement of Sickle Cell Research (CASiRe) is an international collaboration investigating clinical severity in SCD using a validated questionnaire and medical chart review standardized across four countries (United States, United Kingdom, Italy and Ghana).

RESULTS

This study, focused on pain crisis incidence and healthcare utilization, included 868 patients, equally represented according to age and gender. HgbSS was the most common genotype. Patients from Ghana used the Emergency Room/Day Hospital for pain more frequently (annualized mean 2.01) than patients from other regions (annualized mean 1.56 U.S.; 1.09 U.K.; 0.02 Italy), while U.K. patients were hospitalized for pain more often (annualized mean: U.K. 2.98) than patients in other regions (annualized mean 1.98 U.S.; 1.18 Ghana; Italy 0.54). Italy's hospitalization rate for pain (annualized mean: 0.57) was nearly 20 times greater than its emergency room/day hospital only visits for pain (annualized mean: 0.03). When categorized by genotype and age, similar results were seen.

CONCLUSIONS

Geographic differences in pain crisis frequency and healthcare utilization may correlate with variable organization of healthcare systems among countries and should be considered regarding trial design, endpoints, and analysis of results when investigating novel agents for clinical benefit.

Effect of Zuranolone vs Placebo in Postpartum Depression: A Randomized Clinical Trial

Importance

Postpartum depression (PPD) is one of the most common medical complications during and after pregnancy, negatively affecting both mother and child.

Objective

To demonstrate the efficacy and safety of zuranolone, a neuroactive steroid γ-aminobutyric acid receptor-positive allosteric modulator, in PPD.

Design, Setting, and Participants

This phase 3, double-blind, randomized, outpatient, placebo-controlled clinical trial was conducted between January 2017 and December 2018 in 27 enrolling US sites. Participant were women aged 18 to 45 years, 6 months or fewer post partum, with PPD (major depressive episode beginning third trimester or ≤4 weeks postdelivery), and baseline 17-item Hamilton Rating Scale for Depression (HAMD-17) score of 26 or higher. Analysis was intention to treat and began December 2018 and ended March 2019.

Interventions

Randomization 1:1 to placebo:zuranolone, 30 mg, administered orally each evening for 2 weeks.

Main Outcomes and Measures

Primary end point was change from baseline in HAMD-17 score for zuranolone vs placebo at day 15. Secondary end points included changes from baseline in HAMD-17 total score at other time points, HAMD-17 response (≥50% score reduction) and remission (score ≤7) rates, Montgomery-Åsberg Depression Rating Scale score, and Hamilton Rating Scale for Anxiety score. Safety was assessed by adverse events and clinical assessments.

Results

Of 153 randomized patients, the efficacy set comprised 150 patients (mean [SD] age, 28.3 [5.4] years), and 148 (98.7%) completed treatment. A total of 76 patients were randomized to placebo, and 77 were randomized to zuranolone, 30 mg. Zuranolone demonstrated significant day 15 HAMD-17 score improvements from baseline vs placebo (-17.8 vs -13.6; difference, -4.2; 95% CI, -6.9 to -1.5; P = .003). Sustained differences in HAMD-17 scores favoring zuranolone were observed from day 3 (difference, -2.7; 95% CI, -5.1 to -0.3; P = .03) through day 45 (difference, -4.1; 95% CI, -6.7 to -1.4; P = .003). Sustained differences at day 15 favoring zuranolone were observed in HAMD-17 response (odds ratio, 2.63; 95% CI, 1.34-5.16; P = .005), HAMD-17 score remission (odds ratio, 2.53; 95% CI, 1.24-5.17; P = .01), change from baseline for Montgomery-Åsberg Depression Rating Scale score (difference, -4.6; 95% CI, -8.3 to -0.8; P = .02), and Hamilton Rating Scale for Anxiety score (difference, -3.9; 95% CI, -6.7 to -1.1; P = .006). One patient per group experienced a serious adverse event (confusional state in the zuranolone group and pancreatitis in the placebo group). One patient in the zuranolone group discontinued because of an adverse event vs none for placebo.

Conclusions and Relevance

In this randomized clinical trial, zuranolone improved the core symptoms of depression as measured by HAMD-17 scores in women with PPD and was generally well tolerated, supporting further development of zuranolone in the treatment of PPD.

Trial Registration

ClinicalTrials.gov Identifier: NCT02978326.

Cancer-Associated Fibroblasts in Pancreatic Ductal Adenocarcinoma Determine Response to SLC7A11 Inhibition

Cancer-associated fibroblasts (CAF) are major contributors to pancreatic ductal adenocarcinoma (PDAC) progression through protumor signaling and the generation of fibrosis, the latter of which creates a physical barrier to drugs. CAF inhibition is thus an ideal component of any therapeutic approach for PDAC. SLC7A11 is a cystine transporter that has been identified as a potential therapeutic target in PDAC cells. However, no prior study has evaluated the role of SLC7A11 in PDAC tumor stroma and its prognostic significance. Here we show that high expression of SLC7A11 in human PDAC tumor stroma, but not tumor cells, is independently prognostic of poorer overall survival. Orthogonal approaches showed that PDAC-derived CAFs are highly dependent on SLC7A11 for cystine uptake and glutathione synthesis and that SLC7A11 inhibition significantly decreases CAF proliferation, reduces their resistance to oxidative stress, and inhibits their ability to remodel collagen and support PDAC cell growth. Importantly, specific ablation of SLC7A11 from the tumor compartment of transgenic mouse PDAC tumors did not affect tumor growth, suggesting the stroma can substantially influence PDAC tumor response to SLC7A11 inhibition. In a mouse orthotopic PDAC model utilizing human PDAC cells and CAFs, stable knockdown of SLC7A11 was required in both cell types to reduce tumor growth, metastatic spread, and intratumoral fibrosis, demonstrating the importance of targeting SLC7A11 in both compartments. Finally, treatment with a nanoparticle gene-silencing drug against SLC7A11, developed by our laboratory, reduced PDAC tumor growth, incidence of metastases, CAF activation, and fibrosis in orthotopic PDAC tumors. Overall, these findings identify an important role of SLC7A11 in PDAC-derived CAFs in supporting tumor growth. SIGNIFICANCE: This study demonstrates that SLC7A11 in PDAC stromal cells is important for the tumor-promoting activity of CAFs and validates a clinically translatable nanomedicine for therapeutic SLC7A11 inhibition in PDAC.

Oncogenic BRAF, unrestrained by TGFβ-receptor signalling, drives right-sided colonic tumorigenesis

Right-sided (proximal) colorectal cancer (CRC) has a poor prognosis and a distinct mutational profile, characterized by oncogenic BRAF mutations and aberrations in mismatch repair and TGFβ signalling. Here, we describe a mouse model of right-sided colon cancer driven by oncogenic BRAF and loss of epithelial TGFβ-receptor signalling. The proximal colonic tumours that develop in this model exhibit a foetal-like progenitor phenotype (Ly6a/Sca1⁺) and, importantly, lack expression of Lgr5 and its associated intestinal stem cell signature. These features are recapitulated in human BRAF-mutant, right-sided CRCs and represent fundamental differences between left- and right-sided disease. Microbial-driven inflammation supports the initiation and progression of these tumours with foetal-like characteristics, consistent with their predilection for the microbe-rich right colon and their antibiotic sensitivity. While MAPK-pathway activating mutations drive this foetal-like signature via ERK-dependent activation of the transcriptional coactivator YAP, the same foetal-like transcriptional programs are also initiated by inflammation in a MAPK-independent manner. Importantly, in both contexts, epithelial TGFβ-receptor signalling is instrumental in suppressing the tumorigenic potential of these foetal-like progenitor cells.

Oncogenic BRAF, unrestrained by TGFβ-receptor signalling, drives right-sided colonic tumorigenesis

Right-sided (proximal) colorectal cancer (CRC) has a poor prognosis and a distinct mutational profile, characterized by oncogenic BRAF mutations and aberrations in mismatch repair and TGFβ signalling. Here, we describe a mouse model of right-sided colon cancer driven by oncogenic BRAF and loss of epithelial TGFβ-receptor signalling. The proximal colonic tumours that develop in this model exhibit a foetal-like progenitor phenotype (Ly6a/Sca1+) and, importantly, lack expression of Lgr5 and its associated intestinal stem cell signature. These features are recapitulated in human BRAF-mutant, right-sided CRCs and represent fundamental differences between left- and right-sided disease. Microbial-driven inflammation supports the initiation and progression of these tumours with foetal-like characteristics, consistent with their predilection for the microbe-rich right colon and their antibiotic sensitivity. While MAPK-pathway activating mutations drive this foetal-like signature via ERK-dependent activation of the transcriptional coactivator YAP, the same foetal-like transcriptional programs are also initiated by inflammation in a MAPK-independent manner. Importantly, in both contexts, epithelial TGFβ-receptor signalling is instrumental in suppressing the tumorigenic potential of these foetal-like progenitor cells.

RAL GTPases mediate EGFR-driven intestinal stem cell proliferation and tumourigenesis

RAS-like (RAL) GTPases function in Wnt signalling-dependent intestinal stem cell proliferation and regeneration. Whether RAL proteins work as canonical RAS effectors in the intestine and the mechanisms of how they contribute to tumourigenesis remain unclear. Here, we show that RAL GTPases are necessary and sufficient to activate EGFR/MAPK signalling in the intestine, via induction of EGFR internalisation. Knocking down Drosophila RalA from intestinal stem and progenitor cells leads to increased levels of plasma membrane-associated EGFR and decreased MAPK pathway activation. Importantly, in addition to influencing stem cell proliferation during damage-induced intestinal regeneration, this role of RAL GTPases impacts on EGFR-dependent tumourigenic growth in the intestine and in human mammary epithelium. However, the effect of oncogenic RAS in the intestine is independent from RAL function. Altogether, our results reveal previously unrecognised cellular and molecular contexts where RAL GTPases become essential mediators of adult tissue homeostasis and malignant transformation.

MNK Inhibition Sensitizes KRAS-Mutant Colorectal Cancer to mTORC1 Inhibition by Reducing eIF4E Phosphorylation and c-MYC Expression

KRAS-mutant colorectal cancers are resistant to therapeutics, presenting a significant problem for ∼40% of cases. Rapalogs, which inhibit mTORC1 and thus protein synthesis, are significantly less potent in KRAS-mutant colorectal cancer. Using Kras-mutant mouse models and mouse- and patient-derived organoids, we demonstrate that KRAS with G12D mutation fundamentally rewires translation to increase both bulk and mRNA-specific translation initiation. This occurs via the MNK/eIF4E pathway culminating in sustained expression of c-MYC. By genetic and small-molecule targeting of this pathway, we acutely sensitize KRASG12D models to rapamycin via suppression of c-MYC. We show that 45% of colorectal cancers have high signaling through mTORC1 and the MNKs, with this signature correlating with a 3.5-year shorter cancer-specific survival in a subset of patients. This work provides a c-MYC-dependent cotargeting strategy with remarkable potency in multiple Kras-mutant mouse models and metastatic human organoids and identifies a patient population that may benefit from its clinical application. SIGNIFICANCE: KRAS mutation and elevated c-MYC are widespread in many tumors but remain predominantly untargetable. We find that mutant KRAS modulates translation, culminating in increased expression of c-MYC. We describe an effective strategy targeting mTORC1 and MNK in KRAS-mutant mouse and human models, pathways that are also commonly co-upregulated in colorectal cancer.This article is highlighted in the In This Issue feature, p. 995.

CRISPR activation screen in mice identifies novel membrane proteins enhancing pulmonary metastatic colonisation

Melanoma represents ~5% of all cutaneous malignancies, yet accounts for the majority of skin cancer deaths due to its propensity to metastasise. To develop new therapies, novel target molecules must to be identified and the accessibility of cell surface proteins makes them attractive targets. Using CRISPR activation technology, we screened a library of guide RNAs targeting membrane protein-encoding genes to identify cell surface molecules whose upregulation enhances the metastatic pulmonary colonisation capabilities of tumour cells in vivo. We show that upregulated expression of the cell surface protein LRRN4CL led to increased pulmonary metastases in mice. Critically, LRRN4CL expression was elevated in melanoma patient samples, with high expression levels correlating with decreased survival. Collectively, our findings uncover an unappreciated role for LRRN4CL in the outcome of melanoma patients and identifies a potential therapeutic target and biomarker.

Implications of Peak Selection in the Interpretation of Unsupervised Mass Spectrometry Imaging Data Analyses

Mass spectrometry imaging can produce large amounts of complex spectral and spatial data. Such data sets are often analyzed with unsupervised machine learning approaches, which aim at reducing their complexity and facilitating their interpretation. However, choices made during data processing can impact the overall interpretation of these analyses. This work investigates the impact of the choices made at the peak selection step, which often occurs early in the data processing pipeline. The discussion is done in terms of visualization and interpretation of the results of two commonly used unsupervised approaches: t-distributed stochastic neighbor embedding and k-means clustering, which differ in nature and complexity. Criteria considered for peak selection include those based on hypotheses (exemplified herein in the analysis of metabolic alterations in genetically engineered mouse models of human colorectal cancer), particular molecular classes, and ion intensity. The results suggest that the choices made at the peak selection step have a significant impact in the visual interpretation of the results of either dimensionality reduction or clustering techniques and consequently in any downstream analysis that relies on these. Of particular significance, the results of this work show that while using the most abundant ions can result in interesting structure-related segmentation patterns that correlate well with histological features, using a smaller number of ions specifically selected based on prior knowledge about the biochemistry of the tissues under investigation can result in an easier-to-interpret, potentially more valuable, hypothesis-confirming result. Findings presented will help researchers understand and better utilize unsupervised machine learning approaches to mine high-dimensionality data.

An Analysis of Racial and Ethnic Backgrounds Within the CASiRe International Cohort of Sickle Cell Disease Patients: Implications for Disease Phenotype and Clinical Research

Millions are affected by sickle cell disease (SCD) worldwide with the greatest burden in sub-Saharan Africa. While its origin lies historically within the malaria belt, ongoing changes in migration patterns have shifted the burden of disease resulting in a global public health concern. We created the Consortium for the Advancement of Sickle Cell Research (CASiRe) to understand the different phenotypes of SCD across 4 countries (USA, UK, Italy, and Ghana). Here, we report the multi-generational ethnic and racial background of 877 SCD patients recruited in Ghana (n = 365, 41.6%), the USA (n = 254, 29%), Italy (n = 81, 9.2%), and the UK (n = 177, 20.2%). West Africa (including Benin Gulf) (N = 556, 63.4%) was the most common geographic region of origin, followed by North America (N = 184, 21%), Caribbean (N = 51, 5.8%), Europe (N = 27, 3.1%), Central Africa (N = 24, 2.7%), and West Africa (excluding Benin Gulf) (N = 21, 2.4%). SCD patients in Europe were primarily West African (73%), European (10%), Caribbean (8%), and Central African (8%). In the USA, patients were largely African American (71%), Caribbean (13%), or West African (10%). Most subjects identified themselves as Black or African American; the European cohort had the largest group of Caucasian SCD patients (8%), including 21% of the Italian patients. This is the first report of a comprehensive analysis of ethnicity within an international, transcontinental group of SCD patients. The diverse ethnic backgrounds observed in our cohort raises the possibility that genetic and environmental heterogeneity within each SCD population subgroup can affect the clinical phenotype and research outcomes.

A RAC-GEF network critical for early intestinal tumourigenesis

RAC1 activity is critical for intestinal homeostasis, and is required for hyperproliferation driven by loss of the tumour suppressor gene Apc in the murine intestine. To avoid the impact of direct targeting upon homeostasis, we reasoned that indirect targeting of RAC1 via RAC-GEFs might be effective. Transcriptional profiling of Apc deficient intestinal tissue identified Vav3 and Tiam1 as key targets. Deletion of these indicated that while TIAM1 deficiency could suppress Apc-driven hyperproliferation, it had no impact upon tumourigenesis, while VAV3 deficiency had no effect. Intriguingly, deletion of either gene resulted in upregulation of Vav2, with subsequent targeting of all three (Vav2-/- Vav3-/- Tiam1-/-), profoundly suppressing hyperproliferation, tumourigenesis and RAC1 activity, without impacting normal homeostasis. Critically, the observed RAC-GEF dependency was negated by oncogenic KRAS mutation. Together, these data demonstrate that while targeting RAC-GEF molecules may have therapeutic impact at early stages, this benefit may be lost in late stage disease.

Age of first pain crisis and associated complications in the CASiRe international sickle cell disease cohort

Pain is a hallmark of Sickle Cell Disease (SCD) affecting patients throughout their life; the first pain crisis may occur at any age and is often the first presentation of the disease. Universal newborn screening identifies children with SCD at birth, significantly improving morbidity and mortality. Without early screening, diagnosis is generally made after disease manifestations appear. The Consortium for the Advancement of Sickle Cell Research (CASiRe) is an international collaborative group evaluating the clinical severity of subjects with SCD using a validated questionnaire and medical chart review, standardized across 4 countries (United States, United Kingdom, Italy and Ghana). We investigated the age of first pain crisis in 555 sickle cell subjects, 344 adults and 211 children. Median age of the first crisis in the whole group was 4 years old, 5 years old among adults and 2 years old among children. Patients from the United States generally reported the first crisis earlier than Ghanaians. Experiencing the first pain crisis early in life correlated with the genotype and disease severity. Early recognition of the first pain crisis could be useful to guide counseling and management of the disease.

The amino acid transporter SLC7A5 is required for efficient growth of KRAS-mutant colorectal cancer

Oncogenic KRAS mutations and inactivation of the APC tumor suppressor co-occur in colorectal cancer (CRC). Despite efforts to target mutant KRAS directly, most therapeutic approaches focus on downstream pathways, albeit with limited efficacy. Moreover, mutant KRAS alters the basal metabolism of cancer cells, increasing glutamine utilization to support proliferation. We show that concomitant mutation of Apc and Kras in the mouse intestinal epithelium profoundly rewires metabolism, increasing glutamine consumption. Furthermore, SLC7A5, a glutamine antiporter, is critical for colorectal tumorigenesis in models of both early- and late-stage metastatic disease. Mechanistically, SLC7A5 maintains intracellular amino acid levels following KRAS activation through transcriptional and metabolic reprogramming. This supports the increased demand for bulk protein synthesis that underpins the enhanced proliferation of KRAS-mutant cells. Moreover, targeting protein synthesis, via inhibition of the mTORC1 regulator, together with Slc7a5 deletion abrogates the growth of established Kras-mutant tumors. Together, these data suggest SLC7A5 as an attractive target for therapy-resistant KRAS-mutant CRC.

0535 Evaluation of Insomnia Symptoms in a Double-Blind, Randomized, Placebo-Controlled Phase 3 Trial of Sage-217 in Postpartum Depression

Introduction

Postpartum depression (PPD) is a specifier of major depressive disorder (MDD) with peripartum onset. SAGE-217, an investigational, oral neuroactive steroid GABAA receptor positive allosteric modulator, demonstrated improvements in depressive and anxiety symptoms versus placebo in a Phase 3 trial in PPD (NCT02978326; ROBIN) and a pivotal trial in MDD (NCT03000530). In PPD and MDD, insomnia symptoms are key diagnostic features, comorbid sleep disorders are frequent, and insomnia is a common residual symptom. Here we conducted post-hoc analyses to assess insomnia symptoms in the ROBIN trial.

Methods

Women (n=151) ages 18-45, ≤6 months postpartum, with PPD (major depressive episode beginning in 3rd trimester or ≤4 weeks postpartum) and a Hamilton Rating Scale for Depression (HAM-D) total score ≥26, were randomized 1:1 to receive outpatient SAGE-217 30mg or placebo for two weeks, with 4 weeks follow-up. Change from baseline (CFB) in HAM-D score at Day 15 was the primary endpoint. Secondary endpoints included CFB in HAM-D at other time points and the Montgomery-Åsberg Depression Rating Scale (MADRS). Post-hoc analyses assessed HAM-D insomnia subscale (HAM-D-Ins) and MADRS individual insomnia item (MADRS-Ins) scores. HAM-D and MADRS measures were evaluated using a mixed-effects model for repeated measures. Safety and tolerability were assessed by adverse event (AE) reporting.

Results

SAGE-217 demonstrated statistically significant Day 15 CFB versus placebo in HAM-D (primary endpoint: -17.8 vs. -13.6, p=0.0028), MADRS (-22.1 vs. -17.6, p=0.0180), and associated insomnia sub-scales/items (difference SAGE-217 vs. placebo; HAM-D-Ins: -1.003, p=0.0038; MADRS-Ins: -0.773, p=0.0116). Significant CFB in insomnia sub-scales/items favoring SAGE-217 were observed by Day 3 (HAM-D-Ins: -0.841, p=0.0142; MADRS-Ins: -0.710, p=0.017) and at Day 45 (HAM-D-Ins: -0.730, p=0.0207; MADRS-Ins: -0.636, p=0.0221). Most common (≥5%) AEs were somnolence, headache, dizziness, upper respiratory tract infection, diarrhea, and sedation.

Conclusion

SAGE-217 demonstrated improvements in depression symptoms, including insomnia symptoms, and was generally well tolerated.

Support

This study was sponsored by Sage Therapeutics, Inc.

Correlation of lipid peroxidation and nitric oxide metabolites, trace elements, and antioxidant enzymes in patients with sickle cell disease

Background

Lipid peroxidation plays a very important role in sickle cell pathophysiology. The formation of malondialdehyde (MDA) in patients with sickle cell disease (SCD) may lead to endothelial dysfunction. Nitric oxide (NO) is a known vasodilator which plays a role in endothelial function. The current study determined the association between MDA and NO metabolites (NOx), trace elements, and antioxidant enzymes (SOD and CAT) in patients with SCD. The ratio of MDA/NOx was also determined as an index of oxidative stress in the study groups.

Methods

This was a cross‐sectional study involving 90 patients with SCD and 50 “healthy” controls. Blood samples (n = 140) were collected from the study groups. The plasma, sera, and red cells were kept at −20°C for biochemical analyses. Hemoglobin (Hb) and NOx levels were determined in the plasma using Labsystem Multiskan MS and Griess reagent system, respectively. Super oxide dismutase (SOD) and catalase (CAT) levels were determined in the red cells using assay kits from Cayman chemicals. Lipid peroxidation biomarker MDA was determined in the sera using the TBARS assay. Levels of iron (Fe), copper (Cu), and zinc (Zn) were also determined in the sera using Variant 240FS. MDA and NOx ratio was computed for the study groups and compared.

Results

Levels of Hb, NOx, SOD, CAT, and Zn were significantly lower in the patients with SCD (P < .001). MDA, Fe, and MDA/ NOx ratio were, however, significantly higher in the patients with SCD (P < .001). There was no significant correlation between MDA and NOx, SOD, CAT, Fe, and Zn in the study groups. MDA, however, correlated positively and significantly with Cu in the HbSS patients with vaso‐occlusive crises (VOC). Gender did not affect the levels of oxidative stress markers.

Conclusions

Findings from this study suggest a link between lipid peroxidation and Cu in HbSS patients with VOC. Increased MDA/NOx ratio may contribute to sickle cell pathophysiology by promoting oxidative stress.

Macropinocytosis Renders a Subset of Pancreatic Tumor Cells Resistant to mTOR Inhibition

Pancreatic ductal adenocarcinoma (PDAC) features a near-universal mutation in KRAS. Additionally, the tumor suppressor PTEN is lost in ∼10% of patients, and in mouse models, this dramatically accelerates tumor progression. While oncogenic KRAS and phosphatidylinositol 3-kinase (PI3K) cause divergent metabolic phenotypes individually, how they synergize to promote tumor metabolic alterations and dependencies remains unknown. We show that in KRAS-driven murine PDAC cells, loss of Pten strongly enhances both mTOR signaling and macropinocytosis. Protein scavenging alleviates sensitivity to mTOR inhibition by rescuing AKT phosphorylation at serine 473 and consequently cell proliferation. Combined inhibition of mTOR and lysosomal processing of internalized protein eliminates the macropinocytosis-mediated resistance. Our results indicate that mTORC2, rather than mTORC1, is an important regulator of protein scavenging and that protein-mediated resistance could explain the lack of effectiveness of mTOR inhibitors in certain genetic backgrounds. Concurrent inhibition of mTOR and protein scavenging might be a valuable therapeutic approach.

A Multimycotoxin Detection Method for Aflatoxins, Ochratoxins, Zearalenone, Sterigmatocystin, and Patulin

In response to the need for a more comprehensive and simple procedure for multiple mycotoxin detection than had heretofore been deyised, a method has been developed for detection of aflatoxins B1, B2, G1, and G2, ochratoxins A and B and their ethyl esters, zearalenone, sterigmatocystin, and patulin. The method is based on selective extraction with acetonitrile-water, defatting with isooctane, and removal of water-soluble components by transfer of the mycotoxins to chloroform. The method has been applied to corn, barley, oats, and wheat. The detection limits achieved are not as low as can be attained with the analytical procedures for the individual mycotoxins, but are low enough to be useful in a screening procedure.

Targeting the Metabolic Response to Statin-Mediated Oxidative Stress Produces a Synergistic Antitumor Response

Statins are widely prescribed inhibitors of the mevalonate pathway, acting to lower systemic cholesterol levels. The mevalonate pathway is critical for tumorigenesis and is frequently upregulated in cancer. Nonetheless, reported effects of statins on tumor progression are ambiguous, making it unclear whether statins, alone or in combination, can be used for chemotherapy. Here, using advanced mass spectrometry and isotope tracing, we showed that statins only modestly affected cancer cholesterol homeostasis. Instead, they significantly reduced synthesis and levels of another downstream product, the mitochondrial electron carrier coenzyme Q, both in cultured cancer cells and tumors. This compromised oxidative phosphorylation, causing severe oxidative stress. To compensate, cancer cells upregulated antioxidant metabolic pathways, including reductive carboxylation, proline synthesis, and cystine import. Targeting cystine import with an xCT transporter-lowering MEK inhibitor, in combination with statins, caused profound tumor cell death. Thus, statin-induced ROS production in cancer cells can be exploited in a combinatorial regimen. SIGNIFICANCE: Cancer cells induce specific metabolic pathways to alleviate the increased oxidative stress caused by statin treatment, and targeting one of these pathways synergizes with statins to produce a robust antitumor response.See related commentary by Cordes and Metallo, p. 151.

Mevalonate Pathway Provides Ubiquinone to Maintain Pyrimidine Synthesis and Survival in p53-Deficient Cancer Cells Exposed to Metabolic Stress

Oncogene activation and loss of tumor suppressor function changes the metabolic activity of cancer cells to drive unrestricted proliferation. Moreover, cancer cells adapt their metabolism to sustain growth and survival when access to oxygen and nutrients is restricted, such as in poorly vascularized tumor areas. We show here that p53-deficient colon cancer cells exposed to tumor-like metabolic stress in spheroid culture activated the mevalonate pathway to promote the synthesis of ubiquinone. This was essential to maintain mitochondrial electron transport for respiration and pyrimidine synthesis in metabolically compromised environments. Induction of mevalonate pathway enzyme expression in the absence of p53 was mediated by accumulation and stabilization of mature SREBP2. Mevalonate pathway inhibition by statins blocked pyrimidine nucleotide biosynthesis and induced oxidative stress and apoptosis in p53-deficient cancer cells in spheroid culture. Moreover, ubiquinone produced by the mevalonate pathway was essential for the growth of p53-deficient tumor organoids. In contrast, inhibition of intestinal hyperproliferation by statins in an Apc/KrasG12D-mutant mouse model was independent of de novo pyrimidine synthesis. Our results highlight the importance of the mevalonate pathway for maintaining mitochondrial electron transfer and biosynthetic activity in cancer cells exposed to metabolic stress. They also demonstrate that the metabolic output of this pathway depends on both genetic and environmental context. SIGNIFICANCE: These findings suggest that p53-deficient cancer cells activate the mevalonate pathway via SREBP2 and promote the synthesis of ubiquinone that plays an essential role in reducing oxidative stress and supports the synthesis of pyrimidine nucleotide.

Epithelial NOTCH Signaling Rewires the Tumor Microenvironment of Colorectal Cancer to Drive Poor-Prognosis Subtypes and Metastasis

The metastatic process of colorectal cancer (CRC) is not fully understood and effective therapies are lacking. We show that activation of NOTCH1 signaling in the murine intestinal epithelium leads to highly penetrant metastasis (100% metastasis; with >80% liver metastases) in KrasG12D-driven serrated cancer. Transcriptional profiling reveals that epithelial NOTCH1 signaling creates a tumor microenvironment (TME) reminiscent of poorly prognostic human CRC subtypes (CMS4 and CRIS-B), and drives metastasis through transforming growth factor (TGF) β-dependent neutrophil recruitment. Importantly, inhibition of this recruitment with clinically relevant therapeutic agents blocks metastasis. We propose that NOTCH1 signaling is key to CRC progression and should be exploited clinically.

Identifying Clinical and Research Priorities in Sickle Cell Lung Disease. An Official American Thoracic Society Workshop Report

Background: Pulmonary complications of sickle cell disease (SCD) are diverse and encompass acute and chronic disease. The understanding of the natural history of pulmonary complications of SCD is limited, no specific therapies exist, and these complications are a primary cause of morbidity and mortality.Methods: We gathered a multidisciplinary group of pediatric and adult hematologists, pulmonologists, and emergency medicine physicians with expertise in SCD-related lung disease along with an SCD patient advocate for an American Thoracic Society-sponsored workshop to review the literature and identify key unanswered clinical and research questions. Participants were divided into four subcommittees on the basis of expertise: 1) acute chest syndrome, 2) lower airways disease and pulmonary function, 3) sleep-disordered breathing and hypoxia, and 4) pulmonary vascular complications of SCD. Before the workshop, a comprehensive literature review of each subtopic was conducted. Clinically important questions were developed after literature review and were finalized by group discussion and consensus.Results: Current knowledge is based on small, predominantly observational studies, few multicenter longitudinal studies, and even fewer high-quality interventional trials specifically targeting the pulmonary complications of SCD. Each subcommittee identified the three or four most important unanswered questions in their topic area for researchers to direct the next steps of clinical investigation.Conclusions: Important and clinically relevant questions regarding sickle cell lung disease remain unanswered. High-quality, multicenter, longitudinal studies and randomized clinical trials designed and implemented by teams of multidisciplinary clinician-investigators are needed to improve the care of individuals with SCD.