Publications by authors named "Udayan Guha"

Small-cell lung cancer (SCLC) is the most fatal form of lung cancer. Intratumoral heterogeneity, marked by neuroendocrine (NE) and non-neuroendocrine (non-NE) cell states, defines SCLC, but the cell-extrinsic drivers of SCLC plasticity are poorly understood. To map the landscape of SCLC tumor microenvironment (TME), we apply spatially resolved transcriptomics and quantitative mass spectrometry-based proteomics to metastatic SCLC tumors obtained via rapid autopsy.

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Unlabelled: MET pathway activation is one of the most common mechanisms of resistance to osimertinib in EGFR-mutant non-small cell lung cancer (NSCLC). We previously demonstrated spatial and temporal heterogeneity in MET pathway activation upon osimertinib resistance in EGFR-mutant NSCLC; however, the functional relevance of these findings is unclear. Here, we generated 19 patient-derived xenografts (PDX) from 9 patients with multi-region and temporal sampling of osimertinib-resistant tumor tissue from patients with EGFR-mutant NSCLC.

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Article Synopsis
  • The study investigates the role of the APOBEC3B (A3B) enzyme in lung cancer, specifically in non-small-cell lung cancer (NSCLC) driven by the epidermal growth factor receptor (EGFR).
  • It was found that A3B expression can limit tumor growth in mouse models but is linked to resistance against EGFR-targeted therapies in tumors.
  • The research suggests that A3B could be targeted to improve the effectiveness of cancer treatments, as its upregulation was observed in both preclinical models and patients undergoing EGFR-targeted therapy.
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Background: Tumor-specific mutated proteins can create immunogenic non-self, mutation-containing 'neoepitopes' that are attractive targets for adoptive T-cell therapies. To avoid the complexity of defining patient-specific, private neoepitopes, there has been major interest in targeting common shared mutations in driver genes using off-the-shelf T-cell receptors (TCRs) engineered into autologous lymphocytes. However, identifying the precise naturally processed neoepitopes to pursue is a complex and challenging process.

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A gradual decline in renal function occurs even in healthy aging individuals. In addition to aging, per se, concurrent metabolic syndrome and hypertension, which are common in the aging population, can induce mitochondrial dysfunction and inflammation, which collectively contribute to age-related kidney dysfunction and disease. This study examined the role of the nuclear hormone receptors, the estrogen-related receptors (ERRs), in regulation of age-related mitochondrial dysfunction and inflammation.

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Diabetes mellitus is the leading cause of cardiovascular and renal disease in the United -States. Despite the beneficial interventions available for patients with diabetes, there remains a need for additional therapeutic targets and therapies in diabetic kidney disease (DKD). Inflammation and oxidative stress are increasingly recognized as important causes of renal diseases.

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Upon viral entry, components of ND10 nuclear bodies converge with incoming DNA to repress viral expression. The infected cell protein 0 (ICP0) of herpes simplex virus 1 (HSV-1) contains a RING-type E3 ubiquitin ligase that targets the ND10 organizer, PML, for proteasomal degradation. Consequently, ND10 components are dispersed and viral genes are activated.

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Osimertinib is a third-generation epidermal growth factor receptor and tyrosine kinase inhibitor (EGFR-TKI) approved for the treatment of lung adenocarcinoma patients harboring EGFR mutations. However, acquired resistance to this targeted therapy is inevitable, leading to disease relapse within a few years. Therefore, understanding the molecular mechanisms of osimertinib resistance and identifying novel targets to overcome such resistance are unmet needs of cancer patients.

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Epidermal growth factor receptor (EGFR) signaling is frequently dysregulated in various cancers. The ubiquitin ligase Casitas B-lineage lymphoma proto-oncogene (Cbl) regulates degradation of activated EGFR through ubiquitination and acts as an adaptor to recruit proteins required for trafficking. Here, we used stable isotope labeling with amino acids in cell culture mass spectrometry to compare Cbl complexes with or without epidermal growth factor (EGF) stimulation.

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Molecular subtypes of small cell lung cancer (SCLC) defined by the expression of key transcription regulators have recently been proposed in cell lines and limited number of primary tumors. The clinical and biological implications of neuroendocrine (NE) subtypes in metastatic SCLC, and the extent to which they vary within and between patient tumors and in patient-derived models is not known. We integrate histology, transcriptome, exome, and treatment outcomes of SCLC from a range of metastatic sites, revealing complex intra- and intertumoral heterogeneity of NE differentiation.

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Phenotype-based screening can identify small molecules that elicit a desired cellular response, but additional approaches are required to characterize their targets and mechanisms of action. Here, we show that a compound termed LCS3, which selectively impairs the growth of human lung adenocarcinoma (LUAD) cells, induces oxidative stress. To identify the target that mediates this effect, we use thermal proteome profiling (TPP) and uncover the disulfide reductases GSR and TXNRD1 as targets.

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Article Synopsis
  • * Our findings reveal significant variations in tumor-infiltrating lymphocytes and T cell receptor (TCR) counts that correlate with survival rates, particularly in osteosarcoma patients.
  • * We identified key immunotherapeutic targets for cancer treatments and validated multiple potential targets, including PRAME, contributing to a framework for immune-targeting strategies in pediatric extracranial solid tumors.
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Immune checkpoint inhibitor (ICI) therapy has been a paradigm shift in the treatment of cancer. ICI therapy results in durable responses and survival benefit for a large number of tumor types. Osimertinib, a third-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) has shown great efficacy treating EGFR mutant lung cancers; however, all patients eventually develop resistance.

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Immune checkpoint inhibitors and adoptive lymphocyte transfer-based therapies have shown great therapeutic potential in cancers with high tumor mutational burden (TMB), such as melanoma, but not in cancers with low TMB, such as mutant epidermal growth factor receptor (EGFR)-driven lung adenocarcinoma. Precision immunotherapy is an unmet need for most cancers, particularly for cancers that respond inadequately to immune checkpoint inhibitors. Here, we employed large-scale MS-based proteogenomic profiling to identify potential immunogenic human leukocyte antigen (HLA) class I-presented peptides in melanoma and EGFR-mutant lung adenocarcinoma.

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The clinical success of EGFR inhibitors in EGFR-mutant lung cancer is limited by the eventual development of acquired resistance. We hypothesize that enhancing apoptosis through combination therapies can eradicate cancer cells and reduce the emergence of drug-tolerant persisters. Through high-throughput screening of a custom library of ∼1,000 compounds, we discover Aurora B kinase inhibitors as potent enhancers of osimertinib-induced apoptosis.

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Article Synopsis
  • - The study evaluated if monitoring circulating tumor DNA (ctDNA) in plasma and saliva can predict how well patients with EGFR-mutant lung adenocarcinoma respond to osimertinib and its resistance mechanisms.
  • - Researchers used three different ctDNA testing methods—ddPCR, NGS, and saliva-based EFIRM liquid biopsy—on samples from 25 patients enrolled in a clinical trial.
  • - Findings revealed that ctDNA progression occurred on average 118 days before traditional imaging methods detected disease progression, and specific mutations indicated resistance to treatment, highlighting the importance of ctDNA monitoring.
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Mutations in the epidermal growth factor receptor (EGFR) tyrosine kinase domain constitutively activate EGFR resulting in lung tumorigenesis. Activated EGFR modulates downstream signaling by altering phosphorylation-driven interactions that promote growth and survival. Secretory carrier membrane proteins (SCAMPs) are a family of transmembrane proteins that regulate recycling of receptor proteins, including EGFR.

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Lung cancer is the leading cause of cancer mortality worldwide. The treatment of patients with lung cancer harboring mutant EGFR with orally administered EGFR tyrosine kinase inhibitors (TKI) has been a paradigm shift. Osimertinib and rociletinib are third-generation irreversible EGFR TKIs targeting the EGFR T790M mutation.

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Because tobacco is a potent carcinogen, secondary causes of lung cancer are often diminished in perceived importance. To assess the extent of inherited susceptibility to small cell lung cancer (SCLC), the most lethal type of lung cancer, we sequenced germline exomes of 87 patients (77 SCLC and 10 extrapulmonary small cell) and considered 607 genes, discovering 42 deleterious variants in 35 cancer-predisposition genes among 43.7% of patients.

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The longitudinal monitoring of actionable oncogenes in circulating tumor DNA (ctDNA) of non-small cell lung cancer (NSCLC) is crucial for clinicians to evaluate current therapeutic response and adjust therapeutic strategies. Saliva-based electric field-induced release and measurement (EFIRM) is liquid biopsy platform to that can directly detect mutation genes with a small volume of samples. Herein, we compared the effectiveness of longitudinal monitoring for the combination of epidermal growth factor receptor ( and phosphatidylinositol-4,5-bisphosphate 3-kinase, catalytic subunit alpha ( mutations between saliva-based EFIRM and plasma-based platforms (ddPCR and NGS) in two advanced NSCLC patients undergoing the treatment with osimertinib before and after local ablative therapy (LAT).

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Genetic association studies on breast cancer on the Indian subcontinent have yielded conflicting results, and the precise effect of these variants on breast cancer pathogenesis is not known. Genomic variants, as obtained from selected studies from the Indian subcontinent, were subjected to random-effects and fixed-effect meta-analysis. Functional annotation of the relevant variants was done through a tried and tested pipeline.

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Clonal evolution of osimertinib-resistance mechanisms in EGFR mutant lung adenocarcinoma is poorly understood. Using multi-region whole-exome and RNA sequencing of prospectively collected pre- and post-osimertinib-resistant tumors, including at rapid autopsies, we identify a likely mechanism driving osimertinib resistance in all patients analyzed. The majority of patients acquire two or more resistance mechanisms either concurrently or in temporal sequence.

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Background: Small cell lung cancer (SCLC) has the strongest association with smoking among lung cancers. The characteristics of never smokers with SCLC is not known.

Research Question: Are the clinical characteristics, prognostic factors, survival, genomic alterations, and tumor mutational burdens of SCLC in patients who have never smoked different from those who have smoked?

Study Design And Methods: A retrospective multicenter cohort study of patients with clinician-confirmed SCLC was performed with the use of a longitudinal and nationally representative electronic medical records database.

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Background: Thymic epithelial tumors are PD-L1-expressing tumors of thymic epithelial origin characterized by varying degrees of lymphocytic infiltration and a predisposition towards development of paraneoplastic autoimmunity. PD-1-targeting antibodies have been evaluated, largely in patients with thymic carcinoma. We sought to evaluate the efficacy and safety of the anti-PD-L1 antibody, avelumab (MSB0010718C), in patients with relapsed, advanced thymic epithelial tumors and conduct correlative immunological studies.

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Intratumor mutational heterogeneity has been documented in primary non-small-cell lung cancer. Here, we elucidate mechanisms of tumor evolution and heterogeneity in metastatic thoracic tumors (lung adenocarcinoma and thymic carcinoma) using whole-exome and transcriptome sequencing, SNP array for copy-number alterations (CNAs), and mass-spectrometry-based quantitative proteomics of metastases obtained by rapid autopsy. APOBEC mutagenesis, promoted by increased expression of APOBEC3 region transcripts and associated with a high-risk APOBEC3 germline variant, correlated with mutational tumor heterogeneity.

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