Publications by authors named "Charles H Yoon"

Background: Serum antibodies to the Merkel oncoprotein (AMERK) are detectable in approximately 50% of patients with Merkel cell carcinoma (MCC) and can be used to monitor for recurrence. The objective of this study was to characterize AMERK levels in patients receiving curative-intent radiation therapy (RT) for MCC and identify associations between AMERK and recurrence.

Methods: This was a retrospective study of patients with MCC who had baseline AMERK measurements before they received curative-intent RT from 2010 to 2020.

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  • CEACAM1 is a cell surface protein that affects immune responses, but its role in tumors is not well understood.
  • The study used specialized antibodies to analyze the presence of CEACAM1 alongside PD1 and PD-L1 in various immune cells from melanoma patients and healthy controls.
  • Results showed high levels of CEACAM1 on immune cells in melanoma patients, particularly in those resistant to treatment, indicating potential pathways for targeted therapies.
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Recent technological innovations have enabled the high-throughput quantification of gene expression and epigenetic regulation within individual cells, transforming our understanding of how complex tissues are constructed. However, missing from these measurements is the ability to routinely and easily spatially localize these profiled cells. We developed a strategy, Slide-tags, in which single nuclei within an intact tissue section are tagged with spatial barcode oligonucleotides derived from DNA-barcoded beads with known positions.

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  • Immune checkpoint blockade (ICB) combined with antiangiogenic agents, like ipilimumab and bevacizumab, shows promise in treating solid tumors, and researchers are investigating how these treatment methods can work better together.
  • In a study involving long-term responding patients, a strong antibody response to EDIL3, a protein linked to poor cancer prognosis, was found to correlate with positive treatment outcomes, highlighting its role in immune responses.
  • Analysis suggests that cancer-associated fibroblasts (CAFs) may produce EDIL3, which impedes immune cell infiltration and contributes to immune exclusion, making EDIL3 a potential target for enhancing the effectiveness of cancer therapies.
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Recent technological innovations have enabled the high-throughput quantification of gene expression and epigenetic regulation within individual cells, transforming our understanding of how complex tissues are constructed. Missing from these measurements, however, is the ability to routinely and easily spatially localise these profiled cells. We developed a strategy, Slide-tags, in which single nuclei within an intact tissue section are 'tagged' with spatial barcode oligonucleotides derived from DNA-barcoded beads with known positions.

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  • Patients with stage IIB or IIC melanoma had a higher chance of their cancer coming back after surgery, but using a drug called pembrolizumab helped them stay cancer-free longer than a placebo.
  • The KEYNOTE-716 trial tested this drug on patients in many hospitals around the world, focusing on those aged 12 and older with specific types of melanoma.
  • After several treatments with pembrolizumab or placebo, researchers looked at how well the drug worked and how safe it was for the patients involved.
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T cells mediate antigen-specific immune responses to disease through the specificity and diversity of their clonotypic T cell receptors (TCRs). Determining the spatial distributions of T cell clonotypes in tissues is essential to understanding T cell behavior, but spatial sequencing methods remain unable to profile the TCR repertoire. Here, we developed Slide-TCR-seq, a 10-μm-resolution method, to sequence whole transcriptomes and TCRs within intact tissues.

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Aims: Blue naevi are benign melanocytic lesions that typically occur in the dermis. Melanoma arising in blue naevus is rare, and shows a molecular profile distinct from conventional forms of cutaneous melanoma and more similar to uveal melanoma and central nervous system (CNS) melanocytomas. In contrast to conventional cutaneous melanoma, these tumour types typically show activating driver mutations in GNAQ or GNA11, a low mutational burden without evidence of a UV signature and a reproducible pattern of chromosomal copy number changes.

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Background: Limited data exists regarding the efficacy of curative hypofractionated radiotherapy (hypo-RT) regimens compared to conventionally-fractionated radiotherapy (conv-RT) for Merkel cell carcinoma (MCC).

Methods: A retrospective analysis of 241 patients diagnosed with non-metastatic MCC from 2005-2021 and who received RT at Dana-Farber/Brigham & Women's Cancer Center. The primary outcome was cumulative incidence of in-field locoregional relapse using Gray's test with competing risks of death and isolated out-of-field recurrence.

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There is a need for better classification and understanding of tumor-infiltrating lymphocytes (TILs). Here, we applied advanced functional genomics to interrogate 9,000 human tumors and multiple single-cell sequencing sets using benchmarked T cell states, comprehensive T cell differentiation trajectories, human and mouse vaccine responses, and other human TILs. Compared with other T cell states, enrichment of T memory/resident memory programs was observed across solid tumors.

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Within the tumour microenvironment, CD4 T cells can promote or suppress antitumour responses through the recognition of antigens presented by human leukocyte antigen (HLA) class II molecules, but how cancers co-opt these physiologic processes to achieve immune evasion remains incompletely understood. Here we performed in-depth analysis of the phenotype and tumour specificity of CD4 T cells infiltrating human melanoma specimens, finding that exhausted cytotoxic CD4 T cells could be directly induced by melanoma cells through recognition of HLA class II-restricted neoantigens, and also HLA class I-restricted tumour-associated antigens. CD4 T regulatory (T) cells could be indirectly elicited through presentation of tumour antigens via antigen-presenting cells.

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Personal neoantigen vaccines have been envisioned as an effective approach to induce, amplify and diversify antitumor T cell responses. To define the long-term effects of such a vaccine, we evaluated the clinical outcome and circulating immune responses of eight patients with surgically resected stage IIIB/C or IVM1a/b melanoma, at a median of almost 4 years after treatment with NeoVax, a long-peptide vaccine targeting up to 20 personal neoantigens per patient ( NCT01970358 ). All patients were alive and six were without evidence of active disease.

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Activating transcription factor 3 (ATF-3), a cyclic AMP-dependent transcription factor, has been shown to play a regulatory role in melanoma, although its function during tumor progression remains unclear. Here, we demonstrate that ATF-3 exhibits tumor suppressive function in melanoma. Specifically, ATF-3 nuclear expression was significantly diminished with melanoma progression from nevi to primary to metastatic patient melanomas, correlating low expression with poor prognosis.

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Single-cell genomics is essential to chart tumor ecosystems. Although single-cell RNA-Seq (scRNA-Seq) profiles RNA from cells dissociated from fresh tumors, single-nucleus RNA-Seq (snRNA-Seq) is needed to profile frozen or hard-to-dissociate tumors. Each requires customization to different tissue and tumor types, posing a barrier to adoption.

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The molecular mechanisms leading to resistance to PD-1 blockade are largely unknown. Here, we characterize tumor biopsies from a patient with melanoma who displayed heterogeneous responses to anti-PD-1 therapy. We observe that a resistant tumor exhibited a loss-of-function mutation in the tumor suppressor gene , whereas a sensitive tumor from the same patient did not.

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Resistance to cytotoxic T cells is frequently mediated by loss of MHC class I expression or IFNγ signaling in tumor cells, such as mutations of or genes. Natural killer (NK) cells could potentially target such resistant tumors, but suitable NK-cell-based strategies remain to be developed. We hypothesized that such tumors could be targeted by NK cells if sufficient activating signals were provided.

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Patients with high-risk stage II melanoma are at significant risk for recurrence after surgical resection. Adjuvant treatment options to lower the risk for distant metastases are limited. Although adjuvant IFN-α2b is associated with improved relapse-free survival in patients with high-risk melanoma, toxicity and limited overall survival benefits limit its use.

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NK cells contribute to protective antitumor immunity, but little is known about the functional states of NK cells in human solid tumors. To address this issue, we performed single-cell RNA-seq analysis of NK cells isolated from human melanoma metastases, including lesions from patients who had progressed following checkpoint blockade. This analysis identified major differences in the transcriptional programs of tumor-infiltrating compared with circulating NK cells.

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Most targeted cancer therapies fail to achieve complete tumor regressions or attain durable remissions. To understand why these treatments fail to induce robust cytotoxic responses despite appropriately targeting oncogenic drivers, here we systematically interrogated the dependence of cancer cells on the BCL-2 family of apoptotic proteins after drug treatment. We observe that multiple targeted therapies, including BRAF or EGFR inhibitors, rapidly deplete the pro-apoptotic factor NOXA, thus creating a dependence on the anti-apoptotic protein MCL-1.

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Background: The Multicenter Selective Lymphadenectomy Trial II results suggest that future radical axillary lymphadenectomy (ALND) will be performed for bulkier metastatic disease. The utility of level III lymph node (LN) dissection in melanoma patients with palpable metastatic axillary disease was assessed.

Methods: We performed a retrospective chart review of patients who underwent ALND (levels I-III) for metastatic melanoma from 2005 to 2017.

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Article Synopsis
  • * The research reveals a resistance program in malignant cells that leads to immune evasion, characterized by T cell exclusion and present before immunotherapy begins; this program can help predict which patients will respond to anti-PD-1 therapy.
  • * Combining CDK4/6 inhibitors with immunotherapy shows promise, as it can suppress the resistance program in cancer cells, induce cell senescence, and reduce tumor growth in mouse models, suggesting new treatment strategies for overcoming resistance to ICI.
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