Genomic Screening Research Articles

Preferences of parents from diverse backgrounds on genomic screening of apparently healthy newborns.

Genomic sequencing has been proposed as a strategy to expand newborn screening. Perspectives on genomic newborn screening from parents of diverse racial, ethnic, and socioeconomic backgrounds are needed to shape equitable implementation of this modality. We conducted 20 semi-structured interviews (15 English, 5 Spanish) and seven focus groups (4 English, 3 Spanish) with parents from diverse backgrounds to assess their perspectives regarding which disorders and variants might be screened, data privacy, and barriers to pursuing specialized care. Parents felt that genomic newborn screening would provide them with improved understanding of their children's health and had the potential to yield health and personal benefits. Themes that became evident included: interest in childhood and family health risks, the value of emotional preparation and personal planning, understanding of uncertain and low-risk results, concerns regarding data privacy, and concerns about support following the receipt of a positive newborn screening result. The expected benefits and concerns expressed by parents of diverse backgrounds regarding genomic newborn screening should guide future policy decisions. Their preferences should be considered prior to the implementation of large-scale genomic newborn screening programs.

Universal newborn screening using genome sequencing: early experience from the GUARDIAN study.

For more than 20 years there has been speculation about a future in which newborns are routinely screened at birth for genetic disorders using genome sequencing, but prospective large-scale studies assessing this vision have only recently begun. Genome sequencing may provide a means of expanding the scope of conditions included in newborn screening programs and improving the positive predictive value of traditional newborn screening. However, the use of genome sequencing for newborn screening has also raised concerns including acceptability, equity, and scalability. By reviewing the initial results of the GUARDIAN study and contrasting them with other pilot studies investigating the use of genome sequencing for large-scale newborn screening, we highlight how the lessons learned from these studies are shaping the future for the implementation of truly universal and equitable newborn genomic screening.

A systematic approach for identifying unique genomic sequences for Fusarium oxysporum f. sp. lactucae race 1 and development of molecular diagnostic tools

Fusarium oxysporum f. sp. lactucae (FOLac) is a soil- and seedborne fungal pathogen that causes Fusarium wilt of lettuce, an important disease threatening global lettuce production. Based on pathogenicity on differential lettuce cultivars, four races (1-4) have been identified, with race 1 the only race detected in the United States, and the closely related, emerging race 4 known only in Europe. The development of race-specific diagnostic tools is hindered by insufficient genomic data to distinguish between the two races and FOLac from other F. oxysporum formae speciales and nonpathogenic isolates. Here, we describe a systematic approach for developing diagnostic markers for FOLac race 1 that utilized a comprehensive sequence database of F. oxysporum to identify 15 unique genomic sequences. Marker specificity was validated through an exhaustive screening process against genomic data from 797 F. oxysporum isolates representing 64 formae speciales and various plants and non-plant substrates. One of the unique sequences was used to develop a TaqMan quantitative polymerase chain reaction assay and a recombinase polymerase amplification assay, both exhibiting 100% sensitivity and specificity when tested against purified DNA from 171 F. oxysporum isolates and 69 lettuce samples. The relationship between qPCR Ct values and colony forming units (CFU)/g values was also determined. This study not only introduces a new marker for FOLac race 1 diagnostics and soil quantitation, but also underscores the value of an extensive genomic database and screening software pipeline for developing molecular diagnostics for F. oxysporum formae speciales and other fungal taxa.

Expanded Newborn Screening Using Genome Sequencing for Early Actionable Conditions

The feasibility of implementing genome sequencing as an adjunct to traditional newborn screening (NBS) in newborns of different racial and ethnic groups is not well understood. To report interim results of acceptability, feasibility, and outcomes of an ongoing genomic NBS study in a diverse population in New York City within the context of the New York State Department of Health Newborn Screening Program. The Genomic Uniform-screening Against Rare Disease in All Newborns (GUARDIAN) study was a multisite, single-group, prospective, observational investigation of supplemental newborn genome screening with a planned enrollment of 100 000 participants. Parent-reported race and ethnicity were recorded at the time of recruitment. Results of the first 4000 newborns enrolled in 6 New York City hospitals between September 2022 and July 2023 are reported here as part of a prespecified interim analysis. Sequencing of 156 early-onset genetic conditions with established interventions selected by the investigators were screened in all participants and 99 neurodevelopmental disorders associated with seizures were optional. The primary outcome was screen-positive rate. Additional outcomes included enrollment rate and successful completion of sequencing. Over 11 months, 5555 families were approached and 4000 (72.0%) consented to participate. Enrolled participants reflected a diverse group by parent-reported race (American Indian or Alaska Native, 0.5%; Asian, 16.5%; Black, 25.1%; Native Hawaiian or Other Pacific Islander, 0.1%; White, 44.7%; 2 or more races, 13.0%) and ethnicity (Hispanic, 44.0%; not Hispanic, 56.0%). The majority of families consented to screening of both groups of conditions (both groups, 90.6%; disorders with established interventions only, 9.4%). Testing was successfully completed for 99.6% of cases. The screen-positive rate was 3.7%, including treatable conditions that are not currently included in NBS. These interim findings demonstrate the feasibility of targeted interpretation of a predefined set of genes from genome sequencing in a population of different racial and ethnic groups. DNA sequencing offers an additional method to improve screening for conditions already included in NBS and to add those that cannot be readily screened because there is no biomarker currently detectable in dried blood spots. Additional studies are required to understand if these findings are generalizable to populations of different racial and ethnic groups and whether introduction of sequencing leads to changes in management and improved health outcomes. ClinicalTrials.gov Identifier: NCT05990179.

The Path to Genomic Screening—Far From Simple, but the Journey Has Begun

The Path to Genomic Screening—Far From Simple, but the Journey Has Begun

Gene Sequencing Study of Mitochondrial Cytochrome Oxidase Subunit I (COI) in Aedes aegypti Mosquito

Aedes aegypti is an important vector from the public health point of view. It transmits pathogens of Dengue and various other diseases. Controlling vector populations is key to reducing disease transmission and it is possible by understanding the taxonomic characteristics of the vectors and their genetic analysis helps in the identification of the genetic variations in species of different geographical areas. The main aim of the present study is the screening of the Aedes mosquito genome of local species as genetic studies give some insights into the vaccine for the treatment of the diseases caused by mosquito species. In the present study, the adult Ae. aegypti collected from Suryapet town where Dengue fever is endemic, used for the mitochondrial Cytochrome Oxidase subunit I (COI) gene sequencing using the techniques of polymerase chain reaction, Electrophoretic separation, spectrophotometric analysis, and BLAST. The mitochondrial COI sequence of 583 bps is published in the National Centre for Biotechnology Information (NCBI) with accession number ON413769. The sequence data was matched with the database available in the NCBI to identify variation in the gene as this gene keeps changing in the organisms and may contribute to the species establishing itself in a particular region due to congenial environmental conditions. One match with the protein called haem copper oxidase subunit I. The transmission of different pathogens in different areas can be ascertained by comparing similar sequence studies documented. Genomic studies involving genetic markers are of immense help in developing the vaccine. The mitochondrial COI gene is the marker often used for evolutionary research. The single nucleotide polymorphisms (SNP) or Restricted fragment length polymorphisms (RFLPs) that occur in DNA also contribute to the vector's adaptability to the different geographical areas and also the survival benefit which are the basis for understanding the vectors thoroughly and their role in disease transmission.

AMG 193, a Clinical Stage MTA-Cooperative PRMT5 Inhibitor, Drives Antitumor Activity Preclinically and in Patients With MTAP-Deleted Cancers.

One of the most robust synthetic lethal interactions observed in multiple functional genomic screens has been dependency on PRMT5 in cancer cells with MTAP deletion. We report the discovery of the clinical stage MTA-cooperative PRMT5 inhibitor AMG 193, which preferentially binds PRMT5 in the presence of MTA and has potent biochemical and cellular activity in MTAP-deleted cells across multiple cancer lineages. In vitro, PRMT5 inhibition induces DNA damage, cell cycle arrest, and aberrant alternative mRNA splicing in MTAP-deleted cells. In human cell line and patient-derived xenograft models, AMG 193 induces robust antitumor activity and is well tolerated with no impact on normal hematopoietic cell lineages. AMG 193 synergizes with chemotherapies or the KRAS G12C inhibitor sotorasib in vitro, and combination treatment in vivo significantly inhibits tumor growth. AMG 193 is demonstrating promising clinical activity, including confirmed partial responses in patients with MTAP-deleted solid tumors from an ongoing phase 1/2 study.

Genotype from Phenotype: Using CRISPR Screens to Dissect Lymphoma Biology.

Genome-wide screens are a powerful technique to dissect the complex network of genes regulating diverse cellular phenotypes. The recent adaptation of the CRISPR-Cas9 system for genome engineering has revolutionized functional genomic screening. Here, we present protocols used to introduce Cas9 into human lymphoma cell lines, produce high-titer lentivirus of a genome-wide sgRNA library, transduce and culture cells during the screen, select cells with a specified phenotype, isolate genomic DNA, and prepare a custom library for next-generation sequencing. These protocols were tailored for loss-of-function CRISPR screens in human B-cell lymphoma cell lines but are highly amenable for other experimental purposes.

CK20-negative Merkel Cell Carcinoma with Concomitant Squamous Cell Carcinoma In-Situ and Metastasis to the Parotid Gland

Abstract Introduction/Objective This report presents a patient with an aggressive CK20-negative neuroendocrine tumor of the dermis with metastasis to the parotid gland and a concomitant squamous cell carcinoma in-situ (SCCIS) and highlights diagnostic challenges of CK20-negative tumors. Methods/Case Report A centennial female with a history of non-melanoma skin cancer and leukemia presented to the dermatology clinic with a one-year history of an enlarging skin lesion on her right cheek and a subcutaneous mass on the right central lateral neck. On examination, the lesion appeared as a rough and raised red papule with a central crust. On CT, a large heterogeneously enhancing right parotid mass with surrounding satellite nodules, adjacent necrotic adenopathy, and an ulcerating subcutaneous mass in the adjacent right face. An incidental 3 mm right upper lobe nodule was identified. The pathology report noted two distinct malignant neoplasms within the specimen. Microscopy revealed ulceration with acanthosis and full thickness keratinocyte atypia, suggesting Bowen’s disease. On microscopic examination of the separate dermal tumor, there were sheets of uniform small cells with a high nuclear to cytoplasmic ratio and scant cytoplasm. IHC staining was positive for the neuroendocrine markers AE1/AE3, CAM5.2, synaptophysin, and CD56. CK20, CK7, and TTF-1 were negative. As some MCC may be negative for CK20, CK20 was performed twice. Differential diagnoses included SCCIS with CK20-negative MCC versus a metastatic neuroendocrine carcinoma of parotid gland to the skin. The patient transitioned to hospice care soon after the diagnosis. Results (if a Case Study enter NA) NA. Conclusion Our patient presents with an interesting case of a CK20-negative MCC with metastasis to the parotid gland. Since CK20 was stained negative twice, it complicated the diagnosis of MCC vs. small cell carcinoma. We suspected a more likely diagnosis of MCC metastasis to the parotid gland due to multiple reported cases (Day et al. 2016). Our patient also had an identifiable Bowen’s disease borderline to the neuroendocrine carcinoma. It is well known of the coexistence of MCC and squamous cell carcinoma in a cutaneous lesion (Suaiti et al. 2019). Thus, a metastatic MCC to the parotid gland is more likely in this case. As MCC is an aggressive cancer that metastasizes quickly, accurate diagnosis is crucial. With recent literature reporting the association of CK20-negativity with VN-MCC, and the presence of UV signature mutations in CK20- negative MCC, genomic screening would be a useful diagnostic tool.

Identification of Novel Genetic Risk Variants Associated with Hidradenitis Suppurativa in an Exome Sequencing Cohort of 92,455 Individuals

Introduction: Hidradenitis suppurativa (HS) is a prevalent and persistent inflammatory skin disorder, lacking a known cure or effective biomarkers for early diagnosis at present. The genetic determinants of HS have not been fully documented, but it is believed to result from a combination of genetic and environmental factors. Methods: To identify relevant HS gene variants in sporadic HS patients, this study utilized longitudinal electronic health records (EHRs) and whole-exome sequencing. DNA exome sequencing data from 92,455 participant samples in the MyCode biobank, linked to Geisinger’s EHR, were analyzed. This cohort included 1,092 HS cases and 91,363 healthy controls. The MyCode EHR has a median longitudinal follow-up of 15 years per participant, with an average of 87 clinical encounters, 687 laboratory tests, and 7 procedures. Results: There were 1,092 (901 females and 191 males) participants aged 14–89 years (median 47 years) with HS (L73.2), indicating a 1.18% prevalence and accounting for a 4.7:1 female-to-male ratio among the individuals presenting for clinical care. γ-secretase complex, syndromic, and autoinflammatory gene variants were assessed. Potential pathogenic variants were identified among 66 individuals in the HS genes studied. Molecularly, the estimated HS variant prevalence was 1:1,400 in the cohort, 12.3% of variant carriers had HS diagnosis in EHR. Conclusions: Using longitudinal EHR data, genomic screening identified HS-associated gene variants in a defined group of sporadic HS patients to augment the clinical diagnosis, particularly in cases of ambiguity. Based on this study, the field of skin disorders can benefit from a personalized approach to HS diagnosis using large-scale sequencing.

Functional genomics screens reveal a role for TBC1D24 and SV2B in antibody-dependent enhancement of dengue virus infection.

Under some conditions, dengue virus (DENV) can hijack IgG antibodies to facilitate its uptake into target cells expressing Fc gamma receptors (FcgR)-a process known as antibody-dependent enhancement (ADE) of infection. Beyond a requirement for FcgR, host dependency factors for this unusual IgG-mediated infection route remain unknown. To identify cellular factors exclusively required for ADE, here, we performed CRISPR knockout (KO) screens in an in vitro system poorly permissive to infection in the absence of IgG antibodies. Validating our approach, a top hit was FcgRIIa, which facilitates the binding and internalization of IgG-bound DENV but is not required for canonical infection. Additionally, we identified host factors with no previously described role in DENV infection, including TBC1D24 and SV2B, which have known functions in regulated secretion. Using genetic knockout and trans-complemented cells, we validated a functional requirement for these host factors in ADE assays performed with monoclonal antibodies and polyclonal sera in multiple cell lines and using all four DENV serotypes. We show that knockout of TBC1D24 or SV2B impaired the binding of IgG-DENV complexes to cells without affecting FcgRIIa expression levels. Thus, we identify cellular factors beyond FcgR that promote efficient ADE of DENV infection. Our findings represent a first step toward advancing fundamental knowledge behind the biology of a non-canonical infection route implicated in disease.IMPORTANCEAntibodies can paradoxically enhance rather than inhibit dengue virus (DENV) infection in some cases. To advance knowledge of the functional requirements of antibody-dependent enhancement (ADE) of infection beyond existing descriptive studies, we performed a genome-scale CRISPR knockout (KO) screen in an optimized in vitro system permissive to efficient DENV infection only in the presence of IgG. In addition to FcgRIIa, a known receptor that facilitates IgG-mediated uptake of IgG-bound, but not naked DENV particles, our screens identified TBC1D24 and SV2B, cellular factors with no known role in DENV infection. We validated a functional role for TBC1D24 and SV2B in mediating ADE of all four DENV serotypes in different cell lines and using various antibodies. Thus, we identify cellular factors beyond Fc gamma receptors that promote ADE mechanisms. This study represents a first step toward advancing fundamental knowledge beyond a poorly understood non-canonical viral entry mechanism.

Dissecting the Reduced Penetrance of Putative Loss-of-Function Variants in Population-Scale Biobanks.

Loss-of-function variants (LoFs) disrupt the activity of their impacted gene. They are often associated with clinical phenotypes, including autosomal dominant diseases driven by haploinsufficiency. Recent analyses using biobanks have suggested that LoF penetrance for some haploinsufficient disorders may be low, an observation that has important implications for population genomic screening. However, biobanks are also rife with missing data, and the reliability of these findings remains uncertain. Here, we examine the penetrance of putative LoFs (pLoFs) using a cohort of ≈24,000 carriers derived from two population-scale biobanks: the UK Biobank and the All of Us Research Program. We investigate several possible etiologies for reduced pLoF penetrance, including biobank recruitment biases, annotation artifacts, missed diagnoses, and incomplete clinical records. Systematically accounting for these factors increased penetrance, but widespread reduced penetrance remained. Therefore, we hypothesized that other factors must be driving this phenomenon. To test this, we trained machine learning models to identify pLoFs with high penetrance using the genomic features specific to each variant. These models were predictive of penetrance across a range of diseases and ploF types, including those with prior evidence for pathogenicity. This suggests that reduced ploF penetrance is in fact common, and care should be taken when counseling asymptomatic carriers.

Innovative Approaches to Strengthening Preventative Care in Contemporary Healthcare: A Systematic Review

Preventative care plays a critical role in reducing disease burden, improving patient outcomes, and lowering healthcare costs in contemporary medicine. However, the effective implementation of preventative care strategies faces numerous challenges, including technological, financial, and social barriers. This systematic review explores innovative approaches aimed at strengthening preventative care in modern healthcare systems. Key innovations include the use of telemedicine, artificial intelligence (AI), personalized medicine, and community-based public health initiatives. Telemedicine and AI have revolutionized early detection and risk assessment, while personalized medicine and genomic screening allow for tailored preventative interventions. Additionally, behavioral economics and health education programs have proven effective in promoting healthier lifestyles and improving adherence to preventative measures. The review evaluates the impact of these innovations on patient outcomes and highlights both the benefits and challenges of implementing these approaches. While the advancements offer promising results, further research is needed to address issues related to equity, ethical concerns, and global applicability. This review provides valuable insights for healthcare providers, policymakers, and researchers looking to enhance the effectiveness of preventative care strategies in contemporary healthcare systems.

Effective Newborn Screening for Type 1 and 3 Primary Hyperoxaluria

IntroductionNewborn Screening programs for a defined set of eligible diseases have been enormously successful, but genomic newborn screening allowing for detection of additional treatable disorders has not been broadly implemented. All three types of primary hyperoxaluria (PH1-3) are rare autosomal recessive diseases caused by distinct defects of glyoxylate metabolism that are diagnosed genetically with certainty. Early diagnosis and treatment are mandatory to avoid renal failure or sequalae associated with persistent hyperoxaluria. MethodsThe prospective pilot study was undertaken within the framework of the German Newborn Screening. DNA samples extracted from dried blood spot cards were screened by multiplex PCR for the two most prevalent mutations: AGXT c.508G>A (PH1) and HOGA1 c.700+5G>T (PH3). Heterozygous AGXT/HOGA1 carriers received repeated spot urine analyses and, in case of persistent hyperoxaluria, complete Sanger sequencing of AGXT and HOGA1 gene, respectively. ResultsBetween March 15th 2022 and June 30th 2023 additional screening for PH1 and PH3 was performed in 77199 out of 222638 newborns included in the regular newborn screening program. No homozygous individuals, but 274 potential carriers for the AGXT mistargeting and 287 potential carriers for the HOGA1 splice variant were identified. Further work up revealed two already symptomatic compound heterozygous infants, one with PH1 (genotype c.508G>A; c.33delC) and one with PH3 (genotype: c.700+5G>T;c.134C>G). A second symptomatic PH1 patient (father of an identified carrier; genotype: c.508G>A;c.508G>A) was uncovered via family history. ConclusionThis pilot study demonstrated the efficacy of a genomic neonatal screening program for primary hyperoxaluria even in relatively small cohorts.

Clinical Significance of a Prospective Large Genomic Screening for SCLC: The Genetic Classification and a Biomarker-Driven Phase 2 Trial of Gedatolisib

IntroductionSCLC has been treated as a single entity resulting in limited survival improvement. Developing effective tools for guiding appropriate therapeutic strategies is crucial. MethodsA total of 1035 SCLCs were prospectively analyzed by a genomic screening platform: LC-SCRUM-Asia. Fresh frozen tumor samples were subjected to a next-generation sequencing system enabling the integrative analysis of cancer-related genes. A phase 2 trial of gedatolisib for SCLC with PI3K/AKT/mTOR pathway mutations was conducted based on this screening. ResultsOn the basis of the treatment outcomes and therapeutic targets, the following five distinct genetic subgroups were identified in SCLC: NSCLC-subgroup (genetic alterations associated with NSCLC, 8.5%); Hotspot-subgroup (targetable hotspot mutations common in tumors, 3.0%); PI3K-subgroup (PI3K/AKT/mTOR pathway mutations, 7.4%); MYC-subgroup (MYC family amplifications, 13.0%); and HME-subgroup (mutations in the histone-modifying enzymes, 17.6%). The NSCLC-subgroup (hazard ratio = 1.57; 95% confidence interval: 1.22–2.03) and MYC-subgroup (hazard ratio = 1.56; 95% confidence interval: 1.26–1.93) had significantly shorter progression-free survivals after first-line platinum-based treatment. The Hotspot-subgroup and MYC-subgroup were candidates for novel targeted therapies. The HME-subgroup had a favorable survival in patients who received programmed cell death protein-1/programmed death-ligand 1 inhibitor-based therapies (p = 0.005, log-rank test) regardless of some overlap with other subgroups. There were 15 patients enrolled into the phase 2 trial of gedatolisib in the PI3K-subgroup, and the overall response rate and the disease control rate were 6.7% and 20%, respectively. The MYC-subgroup or NSCLC-subgroup was associated with unfavorable clinical outcomes in this trial. ConclusionsMolecular classification of SCLC by genetic approach is beneficial for predicting the treatment outcomes and effectively guiding the clinical choices.

Single-cell multi-modal integrative analyses highlight functional dynamic gene regulatory networks directing human cardiac development.

Illuminating the precise stepwise genetic programs directing cardiac development provides insights into the mechanisms of congenital heart disease and strategies for cardiac regenerative therapies. Here, we integrate invitro and invivo human single-cell multi-omic studies with high-throughput functional genomic screening to reveal dynamic, cardiac-specific gene regulatory networks (GRNs) and transcriptional regulators during human cardiomyocyte development. Interrogating developmental trajectories reconstructed from single-cell data unexpectedly reveal divergent cardiomyocyte lineages with distinct gene programs based on developmental signaling pathways. High-throughput functional genomic screens identify key transcription factors from inferred GRNs that are functionally relevant for cardiomyocyte lineages derived from each pathway. Notably, we discover a critical heat shock transcription factor 1 (HSF1)-mediated cardiometabolic GRN controlling cardiac mitochondrial/metabolic function and cell survival, also observed in fetal human cardiomyocytes. Overall, these multi-modal genomic studies enable the systematic discovery and validation of coordinated GRNs and transcriptional regulators controlling the development of distinct human cardiomyocyte populations.

Secondary metabolites with antimicrobial activity produced by thermophilic bacteria from a high-altitude hydrothermal system.

Thermophilic microorganisms possess several adaptations to thrive in high temperature, which is reflected as biosynthesis of proteins and thermostable molecules, isolation and culture represent a great methodological challenge, therefore High throughput sequencing enables screening of the whole bacterial genome for functional potential, providing rapid and cost-effective information to guide targeted cultures for the identification and characterization of novel natural products. In this study, we isolated two thermophilic bacterial strains corresponding to Bacillus LB7 and Streptomyces LB8, from the microbial mats in the Atacama Desert. By combining genome mining, targeted cultures and biochemical characterization, we aimed to identify their capacity to synthesize bioactive compounds with antimicrobial properties. Additionally, we determined the capability to produce bioactive compounds under controlled in vitro assays and detected by determining their masses by Thin-Layer Chromatography/Mass Spectrometry (TLC/MS). Overall, both isolates can produce antimicrobial (e.g., Myxalamide C by-product) and antioxidants (e.g. Dihydroxymandelic Acid, Amide biotine and Flavone by-products) compounds. Bacillus LB7 strain possesses a more diverse repertoire with 51.95% of total metabolites unmatched, while Streptomyces LB8 favors mainly antioxidants, but has over 70% of unclassified compounds, highlighting the necessity to study and elucidate the structure of novel compounds. Based on these results, we postulate that the uncultured or rare cultured thermophiles inhabiting high-altitude hydrothermal ecosystems in the Atacama Desert offer a promising opportunity to the study of novel microbial bioactive compounds.

Correction of a widespread bias in pooled chemical genomics screens improves their interpretability.

Chemical genomics is a powerful and increasingly accessible technique to probe gene function, gene-gene interactions, and antibiotic synergies and antagonisms. Indeed, multiple large-scale pooled datasets in diverse organisms have been published. Here, we identify an artifact arising from uncorrected differences in the number of cell doublings between experiments within such datasets. We demonstrate that this artifact is widespread, show how it causes spurious gene-gene and drug-drug correlations, and present a simple but effective post hoc method for removing its effects. Using several published datasets, we demonstrate that this correction removes spurious correlations between genes and conditions, improving data interpretability and revealing new biological insights. Finally, we determine experimental factors that predispose a dataset for this artifact and suggest a set of experimental and computational guidelines for performing pooled chemical genomics experiments that will maximize the potential of this powerful technique.

Tailoring a CRISPR/Cas-based Epigenome Editor for Programmable Chromatin Acylation and Decreased Cytotoxicity.

Engineering histone acylation states can inform mechanistic epigenetics and catalyze therapeutic epigenome editing opportunities. Here, we developed engineered lysine acyltransferases that enable the programmable deposition of acetylation and longer-chain acylations. We show that targeting an engineered lysine crotonyltransferase results in weak levels of endogenous enhancer activation yet retains potency when targeted to promoters. We further identify a single mutation within the catalytic core of human p300 that preserves enzymatic activity while substantially reducing cytotoxicity, enabling improved viral delivery. We leveraged these capabilities to perform single-cell CRISPR activation screening and map enhancers to the genes they regulate in situ. We also discover acylation-specific interactions and find that recruitment of p300, regardless of catalytic activity, to prime editing sites can improve editing efficiency. These new programmable epigenome editing tools and insights expand our ability to understand the mechanistic role of lysine acylation in epigenetic and cellular processes and perform functional genomic screens.

Abstract C091: Uncovering genetic regulators of metabolic plasticity in renal cell carcinoma

Abstract We aim to offer new insights on the regulation of metabolic plasticity in renal cell carcinoma (RCC) and identify novel metabolic regulatory targets that can be used for potential treatment therapies of the disease. RCC affects an estimated 400,000 people worldwide each year with over 100,00 deaths annually that disproportionately affects racial/ethnic minorities in the United States. RCC is a term that covers an array of kidney cancer subtypes differing in incidence, histopathology, genetic and molecular alterations, as well as in clinical outcomes and prognoses. However, a common characteristic of many RCCs is that they are driven by metabolic rewiring, due to a high frequency of mutations in genes that regulate major metabolic processes in the cell. It was recently discovered that patient overall survival and prognosis has been linked to the expression of certain metabolic signatures in RCC tumor cells. Metabolic plasticity allows cancer cells to survive and adapt to different environments and metabolic stress conditions, such as nutrient deprivation. Therefore, exploring and exploiting metabolic rewiring in these cells may reveal genetic vulnerabilities and dependencies. This could lead to discovery of novel biomarkers and molecular targets that can be implicated as future therapeutic interventions for this disease. To this end, we applied functional genomic screening to expose genetic dependencies and vulnerabilities under different physiologic and metabolic conditions in patient derived medullary (PDM) RCC cells. The medullary RCC is a rare and aggressive RCC subtype that disproportionately affects the African American/Black population. We applied a CRISPR- based combinatorial screening platform that is based on co-expression of Cas9 and Cas12a nucleases and libraries of hybrid guide RNAs (hgRNA) to achieve ultra-efficient gene knockout (Aregger et al., 2021; Gonatopoulos-Pournatzis et al., 2020) in PDM RCC cells. Additionally, cells were screened under different media conditions that mimic human physiological nutrient conditions and a media deprived of lipids, one of the major metabolic substrates of the cell. By utilizing a genome-wide pooled CRISPR gene knockout screen we were able to systematically uncover genes required for cell survival and proliferation in a panel of patient-derived RCCs. We have begun to uncover genetic dependencies and major metabolic pathways that can be elucidated and exploited for future studies, such as those involving ferroptosis which is a targetable pathway for the development of cancer treatment therapies. Our findings demonstrate some of the key genetic drivers underlying cellular adaptations to different physiological environments and nutrient deprivation. In future studies we will further explore the relationship between different key metabolic regulatory genes in RCC and map for genetic interactions in major metabolic pathways. Citation Format: Chelsee Holloway, Josef Horak, Youngkyu Jeon, Michael Aregger. Uncovering genetic regulators of metabolic plasticity in renal cell carcinoma [abstract]. In: Proceedings of the 17th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2024 Sep 21-24; Los Angeles, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2024;33(9 Suppl):Abstract nr C091.