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Thin, T. H.

Publications and source records attributed to Thin, T. H..

5 recordsLinked to original sources

ATM functions as a rheostat of metabolic stress in small-cell lung cancer

ATM is best known as a guardian of genomic stability, yet its contributions to oncogenic signaling in aggressive malignancies like small-cell lung cancer (SCLC) remain poorly understood. Despite ATM being an established clinical vulnerability in SCLC, its influence on dysregulated tumorigenic circuits remains unclear. We demonstrate that inhibition of ATM disrupts the AKT-mTORC1-4EBP1 signaling axis, leading to attenuation of the master regulator of stress, ATF4. ATF4 and MYC appear to co-regulate one another in a feedback loop critical for redox homeostasis. ATM inhibition perturbs both the expression and function of MYC and ATF4, leading to increased intracellular reactive oxygen species, impaired glutathione recycling, and ferroptotic cell death, thereby exposing a crucial dependency of SCLC on stress-adaptive signaling. We uncover previously unrecognized metabolic vulnerability in SCLC, nominating ATM as a regulator of adaptive stress, expanding its role beyond canonical DNA damage repair (DDR) and highlighting therapeutically exploitable opportunities in aggressive tumors. Statement of SignificanceThe metabolic landscape of SCLC remains poorly characterized, particularly its interaction with dysregulated signaling networks, limiting the development of effective strategies to overcome therapeutic resistance. Our work reveals an expanded role for ATM beyond DNA repair, positioning it as a key regulator of metabolic rewiring and highlighting new therapeutic opportunities for SCLC.

cancer biology↗

GM-CSF regulates ILC states and myeloid cell signaling during ulceration in Crohns disease

Macrophage (M-), granulocyte (G-), and granulocyte-macrophage (GM-) colony-stimulating factors (CSFs) regulate myeloid cell function, yet their relative roles during inflammation remain poorly defined. To uncover how CSFs shape spatial immune niches in Crohns disease, we performed Xenium single-cell spatial transcriptomics on ileal tissues, revealing cell-type-specific expression and source-target interactions for each CSF. GM-CSF, unlike M-CSF or G-CSF, was locally enriched in ulcerated regions where lymphocytes adjacent to macrophage aggregates signaled through STAT5 phosphorylation. To study functional consequences, we developed a csf2rb-/- zebrafish model of intestinal injury. Using this model, we found that loss of GM-CSF signaling exacerbated epithelial damage and inflammation, whereas recombinant human GM-CSF limited injury by restraining ILC1 expansion, sustaining ILC3 maintenance, and promoting IL-22 production. Cross-species single-cell analysis revealed conserved ILC gene modules and GM-CSF-dependent transcriptional networks linking lymphoid and myeloid populations. These findings establish GM-CSF as a critical spatial regulator of myeloid- lymphoid crosstalk and intestinal immune homeostasis in Crohns disease.

immunology↗

HLA-E and NKG2A Mediate Resistance to M. bovis BCG Immunotherapy in Non-Muscle-Invasive Bladder Cancer

BackgroundBacillus Calmette-Guerin (BCG) is the standard of care treatment for high-risk non-muscle-invasive bladder cancer (NMIBC), yet many patients develop recurrent disease despite evidence of ongoing immune activation. We investigated mechanisms of immune escape in BCG-unresponsive tumors and evaluated the therapeutic potential of targeting the HLA-E/NKG2A axis. MethodsSingle-cell RNA sequencing, spatial immunophenotyping, proteomic profiling, and functional ex vivo assays were performed using tumors and urine samples from patients with BCG-naive and BCG-unresponsive NMIBC. ResultsBCG-unresponsive tumors were enriched for HLA-E-expressing malignant cells compared with BCG-naive tumors. Increased HLA-E expression was associated with enhanced IFN-{gamma} signaling and was induced by IFN-{gamma} stimulation in primary tumor cells and bladder cancer tumor lines. Spatial analyses demonstrated accumulation of NKG2A+ NK and CD8 T cells in proximity to HLA-Ehigh tumor cells, with increased NKG2A:HLA-E interactions in BCG-unresponsive tumors. Despite high expression of cytotoxic mediators, NKG2A+ effector cells displayed impaired degranulation. Blockade of NKG2A with monalizumab restored degranulation of and cytotoxicity by tumor-infiltrating lymphocytes in autologous tumor co-cultures. ConclusionsBCG-unresponsive NMIBC tumors are enriched for HLA-E-expressing tumor cells and NKG2A+ effector lymphocytes, with increased engagement of the HLA-E/NKG2A axis within the tumor microenvironment. These findings identify the HLA-E/NKG2A axis as a therapeutic vulnerability and provide a rationale for clinical evaluation of NKG2A blockade as a bladder-sparing strategy for patients with BCG-unresponsive disease.

cancer biology↗

Elevated HLA-E and NKG2A as a consequence of chronic immune activation defines resistance to M. bovis BCG immunotherapy in Non-Muscle-Invasive Bladder Cancer

Mycobacterium bovis Bacillus Calmette-Guerin (BCG), the first-line treatment for non-muscle invasive bladder cancer (NMIBC), promotes the production of inflammatory cytokines, particularly interferon (IFN)-{gamma}. Prolonged inflammation and IFN-{gamma} exposure are known to cause an adaptive immune response, enabling immune escape and proliferation by tumor cells. We investigated HLA-E and NKG2A, a novel T and NK cell checkpoint pathway, as a driver of adaptive resistance in BCG unresponsive NMIBC. We observed ubiquitous inflammation in all patients after BCG immunotherapy, regardless of recurrence status. IFN-{gamma} was shown to drive tumor expression of HLA-E and PD-L1. Further, NKG2A-expressing NK and CD8 T cells were enriched in BCG unresponsive tumors and with enhanced capacity for cytolytic functions. Strikingly, in situ spatial analyses revealed that HLA-EHIGH tumors are activated to recruit NK and T cells via chemokine production, potentially sparing HLA-ELOW tumors that would otherwise be susceptible to lysis. Finally, blood-derived NK cells retained anti-tumor functions at the time of tumor recurrence. These data support combined NKG2A and PD-L1 blockade for BCG unresponsive disease.

immunology↗

NKG2A and HLA-E define a novel alternative immune checkpoint axis in bladder cancer

PD-1/PD-L1-blockade immunotherapies have limited efficacy in the treatment of muscle-invasive bladder cancer (MIBC) and metastatic urothelial carcinoma. Here, we show that KLRC1 (NKG2A) expression associates with improved survival and responsiveness to PD-L1 blockade immunotherapy in CD8Ahigh bladder tumors. The loss of antigen presentation is a common mechanism for tumor escape in bladder cancer. NKG2A+ CD8 T cells are able to circumvent HLA-ABC loss through TCR-independent cytotoxicity, which is partly mediated by DNAM-1. In bladder tumors, NKG2A is acquired on a subset of PD-1+ CD8 T cells, alongside stronger tissue-residency memory features, TCR-independent cytotoxicity and evidence of recent proliferation. HLA-E is low but variably expressed on bladder tumors. When expressed, NKG2A+ CD8 T cell anti-tumor responses to HLA-ABC-deficient tumors are inhibited and partly restored upon NKG2A blockade. Overall, our study identifies an alternative path for CD8 T cell exhaustion, that is mediated by NKG2A upregulation and TCR-independent cytotoxicity.

immunology↗