Gad Getz

Actionable genetic landscape and dynamics in circulating DNA from 12,827 patients with metastatic breast cancer

Plasma cell-free DNA (cfDNA) is a sensitive, noninvasive tool for monitoring the genomic landscape, heterogeneity, and evolution of cancer, aggregating genetic information from multiple metastatic sites. Here, we study 15,564 cfDNA samples from 12,827 patients with metastatic breast cancer (MBC). We classify samples, deep-sequenced with Guardant360, into MBC subtypes using our trained random forest model. Most patients have variants associated with therapeutic resistance and targetability of approved and experimental therapies, including in PIK3CA, ESR1, PTEN , and AKT1 . Frequencies of multiple actionable alterations differed from primary disease, and multiple variants per gene suggest independent resistant clones. The large cohort size enables uncovering clonal co-behaviors, including co-existence and exclusivity of alleles and correlation of allele fractions. cfDNA testing is now recommended in multiple advanced malignancies, including eligibility assessment for clinical trials. We envision this large collection of MBC cfDNA data as an invaluable resource for the design and planning of future clinical trials.

Follicular Lymphoma Transformation is Characterized by Cytokine-associated Remodeling of Stromal and Macrophage Compartments

Tabular foundation model predicts alternative lengthening of telomeres (ALT) and identifies SMARCAL1 as a target in ALT-driven cancers

Alternative lengthening of telomeres (ALT) is a telomerase-independent pathway used by aggressive cancers to maintain their replicative immortality. Because ALT is absent from normal human cells, it is an appealing target for cancer therapy, but the lack of ability to determine ALT status at scale has hindered discovery. Here, we developed ALTitude, a machine learning method from a tabular foundation model that infers ALT from cell line whole genome sequencing data, without need for paired germline analysis. We deployed ALTitude across the DepMap, doubling the number of known ALT+ cancer models. Systematic integration of ALTitude with CRISPR-Cas9 screens yielded the selective dependency on SMARCAL1 in ALT+ cell lines, where we show it stabilizes the ALT phenotype. Acute depletion of SMARCAL1 leads to G2/M arrest, mitotic catastrophe, and cell death. These data provide a valuable resource for studying ALT-related genomic features and present SMARCAL1 as a therapeutic target for ALT+ malignancies.

Identification of persister cells and evolution of tumor clones during immunotherapy and at minimal residual disease timepoints decoded by single-cell whole-genome sequencing in multiple myeloma

Systematic molecular profiling to identify determinants of response to ibrutinib

Single-cell immune profiling reveals enhanced immune fitness of endogenous and engineered T cells in patients with high-risk smoldering myeloma compared to Relapsed/Refractory myeloma following bispecific antibodies or CAR-T cell therapies.

Spatial proteomics of the bone marrow reveals distinct Tumor–Immune niches in smoldering and relapsed myeloma and their remodeling in response to bispecific antibody and CAR-T therapy

Exploring penetrance of clinically relevant variants in over 800,000 humans from the Genome Aggregation Database

Incomplete penetrance, or absence of disease phenotype in an individual with a disease-associated variant, is a major challenge in variant interpretation. Studying individuals with apparent incomplete penetrance can shed light on underlying drivers of altered phenotype penetrance. Here, we investigate clinically relevant variants from ClinVar in 807,162 individuals from the Genome Aggregation Database (gnomAD), demonstrating improved representation in gnomAD version 4. We then conduct a comprehensive case-by-case assessment of 734 predicted loss of function variants in 77 genes associated with severe, early-onset, highly penetrant haploinsufficient disease. Here, we identify explanations for the presumed lack of disease manifestation in 701 of 734 variants (95%). Individuals with unexplained lack of disease manifestation in this set of disorders are rare, underscoring the need and power of deep case-by-case assessment presented here to minimize false assignments of disease risk, particularly in unaffected individuals with higher rates of secondary properties that result in rescue.

Long-term Survival and Molecular Biomarker Evaluation of a Phase II Cetuximab and Nivolumab Clinical Trial in Recurrent/Metastatic Head and Neck Cancer

Single-cell RNA-sequencing of BCG naïve and recurrent non-muscle invasive bladder cancer reveals a CD6/ALCAM-mediated immune-suppressive pathway

Bacillus Calmette-Guérin (BCG) is the mainstay of treatment for intermediate- and high-risk non-muscle invasive bladder cancer (NMIBC), yet recurrence rates remain high. To improve the efficacy of BCG, a better understanding of the immune landscape underlying BCG resistance is critical. Here, we performed single-cell RNA-sequencing (scRNA-seq) and whole-exome sequencing on tumors from NMIBC patients before and after BCG treatment. Our analysis revealed a marked increase in CD6/ALCAM interactions between T cells and urothelial cells in BCG recurrent tumors. CD6-high T cells were enriched in recurrent tumors and exhibited downregulation of activation-related genes, indicative of functional impairment. These observations were supported by analysis of an independent BCG-treated NMIBC cohort, in which CD6/ALCAM signaling was correlated with shorter recurrence-free survival (p = 0.00059). Our findings reveal a previously unrecognized association between CD6/ALCAM signaling and BCG resistance in NMIBC patients and highlight this pathway as a potential therapeutic target to enhance response to BCG.

Detection of heterogeneous resistance mechanisms to tyrosine kinase inhibitors from cell-free DNA

Though there has been substantial progress in the development of anti-human epidermal growth factor receptor 2 (HER2) therapies to treat HER2-positive metastatic breast cancer (MBC) within the past two decades, most patients still experience disease progression and cancer-related death. HER2-directed tyrosine kinase inhibitors can be highly effective therapies for patients with HER2-positive MBC; however, an understanding of resistance mechanisms is needed to better inform treatment approaches. We performed whole-exome sequencing on 111 patients with 73 tumor biopsies and 120 cell-free DNA samples to assess mechanisms of resistance. In 11 of 26 patients with acquired resistance, we identified alterations in previously characterized genes, such as PIK3CA and ERBB2, that could explain treatment resistance. Mutations in growing subclones identified potential mechanisms of resistance in 5 of 26 patients and included alterations in ESR1, FGFR2, and FGFR4. Additional studies are needed to assess the functional role and clinical utility of these alterations in driving resistance.

Data from Generation of a Biliary Tract Cancer Cell Line Atlas Identifies Molecular Subtypes and Therapeutic Targets

Supplementary Figures S1-S9 from Generation of a Biliary Tract Cancer Cell Line Atlas Identifies Molecular Subtypes and Therapeutic Targets

Tamoxifen induces PI3K activation in uterine cancer

Differential T cell clonal dynamics underlie outcomes to frontline chemoimmunotherapy in advanced gastric cancer

Numbat-multiome: inferring copy number variations by combining RNA and chromatin accessibility information from single-cell data

Aberrant alterations in genome copy number, chromatin accessibility, and transcriptional programs all play pivotal roles in cancer. The Numbat algorithm has been widely adopted to perform copy number variation (CNV) inference from single-cell RNA sequencing (scRNA-seq) data. Here, we introduce Numbat-multiome that extends the capabilities of Numbat to perform CNV inference from both scRNA-seq and accessible chromatin profiles (through single-cell Assay of Transposase [Tn5]-Accessible Chromatin sequencing [scATAC-seq] data), either separately or in an integrated manner. Our approach unifies data originating from different modalities through a binning strategy that relies on a common genomic coordinate system across modalities. We demonstrate the tool's robust performance in four running modes (RNA gene, RNA bin, ATAC bin, and Combined bin) using benchmark cohorts of tumors with dynamic changes in expression patterns and copy number heterogeneity, including early-stage multiple myeloma and Richter's syndrome arising from chronic lymphocytic leukemia, validated against whole-genome sequencing. Numbat-multiome achieves high precision and recall (median F1>0.9) across different CNV event types, with consistent performance across sample types and event lengths. The tool's ability to track clonal evolution in serial samples and identify rare subclones allows for integration of epigenomic profiles at the subclonal level, providing new insights into the stepwise genetic and epigenetic changes underlying cancer phenotypic shifts.

A Diffusion-Based Autoencoder for Learning Patient-Level Representations from Single-Cell Data

A clonally expanded nodal T-cell population diagnosed as T-cell lymphoma after CAR-T therapy

Integrative analysis of lung adenocarcinoma across diverse ethnicities and exposures

Lung adenocarcinomas (LUAD) are a pressing global health problem with enduring lethality and rapidly shifting epidemiology. Proteogenomic studies integrating proteomics and post-translational modifications with genomics can identify clinical strata and oncogenic mechanisms, but have been underpowered to examine effects of ethnicity, smoking and environmental exposures, or sex on this heterogeneous disease. This comprehensive proteogenomic analysis of LUAD tumors and matched normal adjacent tissues from 406 patients across diverse geographic and demographic backgrounds explores the impact of understudied driver mutations, prognostic role of chromosomal instability, patterns of immune signaling, differential and sex-specific effects of endogenous mutagens and environmental carcinogens, and pathobiology of early-stage tumors with "late-like" characteristics. Candidate protein biomarkers are proposed for unstable tumors with highly fragmented genomes and for carcinogen exposures, and a LUAD subtype-specific atlas of therapeutic vulnerabilities is presented. These observations and the associated data resource advance the objective of precision management strategies for this devastating disease.

Disease-specific U1 spliceosomal RNA mutations in mature B-cell neoplasms

Recurrent mutations in the third base of U1 spliceosomal RNA responsible for marked splicing and expression abnormalities have been described in chronic lymphocytic leukemia (CLL) and some solid tumors. However, the clinical significance of these mutations in large and independent CLL cohorts as well as their presence in other B-cell neoplasms is unknown. Here we characterized U1 mutations in 1670 CLL and 363 mature B-cell lymphomas. We confirmed that the g.3A>C U1 mutation is found in 3.5% of CLL, which conferred rapid disease progression independently of the main biological and clinical prognostic markers of the disease. Additionally, a recurrent g.9C>T mutation was found in 1.5% of CLL causing downstream splicing alterations and associated with adverse prognosis. We also identified a g.4C>T mutation in 10% of diffuse large B-cell lymphomas of the germinal center subtype and a g.7A>G mutation in 30% of EBV-negative Burkitt lymphomas, both of which altered the splicing pattern of multiple genes. This study reveals novel, recurrent, and tumor-specific U1 mutations in mature B-cell neoplasms with biological and prognostic implications, thus establishing U1 as a novel pan-B-cell malignancy driver gene.