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Biology subjects

Owen, D. H.

Publications and source records attributed to Owen, D. H..

3 recordsLinked to original sources

Targeting alpha-ketoglutarate starvation within the tumor-immune microenvironment rescues T cell effector function in cancer immunotherapy

Given its status as the leading cause of global cancer mortality, there is a critical need to enhance immunotherapy strategies for lung cancer to overcome widespread resistance to current treatments. Immunotherapy recruits the patient's immune system to attack and destroy cancer cells. While highly effective in a subset of patients, chronic exposure of immune cells to cancer cells leads to a progressive loss of effector T cell function and progression of T cell exhaustion; now considered two well-established hallmarks of immunotherapy resistance. The tumor-immune microenvironment (TIME)-driven differentiation into the exhausted T cell phenotype is marked by a loss of metabolic plasticity and epigenome-wide changes in distribution of repressive histone marks such as histone H3 subunit methylation at lysine 27 (H3K27me3). Here, we studied how these processes are connected to metabolite availability within the TIME. In vitro, chronic antigen stimulation and hypoxia led to rapid loss of effector function, associated with a suppression of alpha-ketoglutarate (aKG) intracellular concentrations in T cells. Supplementation of cell-permeable aKG led to a rescue of effector cytokine production and to improved cytotoxic capacity despite chronic antigen stimulation and hypoxia. Increased intracellular aKG levels restored the activity of H3K27 demethylases UTX and JMJD3, consistent with epigenome-wide decreased H3K27me3. In vivo, dietary supplementation with commercially available calcium-aKG (Ca-aKG) supplements led to an elevation of serum and intratumoral aKG levels associated with a significant increase of immunotherapy effectiveness in mouse models of NSCLC. Clinical samples from patients with NSCLC contained significantly decreased serum aKG levels in older NSCLC patients (>65 years of age). Analysis identified a novel association between serum aKG levels and poor immunotherapy response. Thus, our work demonstrates that intratumoral metabolite starvation can be therapeutically exploited to improve immunotherapy outcomes in non-small cell lung cancer (NSCLC).

cancer biology↗

Hepatobiliary Progenitor-like Reprogramming in Liver Metastases

Metastatic progression requires cancer cells to adapt to the unique constraints of distant organ microenvironments, yet the mechanisms that drive organ-specific adaptations remain poorly understood. Here, we show that the liver actively rewrites metastatic cancer cell identity, driving tumor cells toward a hepatobiliary progenitor-like state. Through integrated transcriptomic, proteomic, metabolomic, and epigenomic analyses of patient-derived rapid-autopsy samples and experimental models, we identify this state as selectively enriched in liver metastases. It is characterized by co-activation of hepatic and biliary/progenitor regulators HNF4A and SOX9 and is observed across multiple epithelial cancers, indicating a conserved response to the hepatic niche. Mechanistically, hepatocyte-derived TGF-{beta} and hypoxia converge to activate a HIF-1-ACLY axis, increasing nuclear acetyl-coenzyme A availability and histone acetylation at hepatic lineage regulatory elements to drive hepatobiliary reprogramming. This coordinated niche-response program can be captured transcriptionally and is associated with inferior overall survival. Disruption of this pathway suppresses hepatic reprogramming and impairs liver metastatic fitness. These findings identify the liver as an active determinant of metastatic cell fate, linking microenvironmental signaling to metabolic and chromatin remodeling programs that enable lineage plasticity. More broadly, they reveal organ-specific reprogramming as a fundamental principle of metastasis and a therapeutic vulnerability in liver metastases.

cancer biology↗

Replicative Instability Drives Cancer Progression

In the past decade, defective DNA repair has been increasingly linked with cancer progression. Human tumors with markers of defective DNA repair and increased replication stress have been shown to exhibit genomic instability and poor survival rates across tumor types. Here we utilize-omics data from two independent consortia to identify the genetic underpinnings of replication stress, therapy resistance, and primary carcinoma to brain metastasis in BRCA wildtype tumors. In doing so, we have defined a new pan-cancer class of tumors characterized by replicative instability (RIN). RIN is defined by genomic evolution secondary to replicative challenge. Our data supports a model whereby defective single-strand break repair, translesion synthesis, and non-homologous end joining effectors drive RIN. Collectively, we find that RIN accelerates cancer progression by driving copy number alterations and transcriptional program rewiring that promote tumor evolution. Statement of SignificanceDefining the genetic basis of genomic instability with wildtype BRCA repair effectors is a significant unmet need in cancer research. Here we identify and characterize a pan-cancer cohort of tumors driven by replicative instability (RIN). We find that RIN drives therapy resistance and distant metastases across multiple tumor types.

cancer biology↗