SARS-CoV-2 mRNA vaccination-induced immunological memory in human nonlymphoid and lymphoid tissues.

Tissue-resident lymphocytes provide organ-adapted protection against invading pathogens. Whereas their biology has been examined in great detail in various infection models, their generation and functionality in response to vaccination have not been comprehensively analyzed in humans. We therefore studied SARS-CoV-2 mRNA vaccine-specific T cells in surgery specimens of kidney, liver, lung, bone marrow, and spleen compared with paired blood samples from largely virus-naive individuals. As opposed to lymphoid tissues, nonlymphoid organs harbored significantly elevated frequencies of spike-specific CD4+ T cells compared with blood showing hallmarks of tissue residency and an expanded memory pool. Organ-derived CD4+ T cells further exhibited increased polyfunctionality over those detected in blood. Single-cell RNA-Seq together with T cell receptor repertoire analysis indicated that the clonotype rather than organ origin is a major determinant of transcriptomic state in vaccine-specific CD4+ T cells. In summary, our data demonstrate that SARS-CoV-2 vaccination entails acquisition of tissue memory and residency features in organs distant from the inoculation site, thereby contributing to our understanding of how local tissue protection might be accomplished.

SUMOylation inhibition overcomes proteasome inhibitor resistance in multiple myeloma.

Proteasome inhibition is a highly effective treatment for multiple myeloma (MM). However, virtually all patients develop proteasome inhibitor resistance, which is associated with a poor prognosis. Hyperactive small ubiquitin-like modifier (SUMO) signaling is involved in both cancer pathogenesis and cancer progression. A state of increased SUMOylation has been associated with aggressive cancer biology. We found that relapsed/refractory MM is characterized by a SUMO-high state, and high expression of the SUMO E1-activating enzyme (SAE1/UBA2) is associated with poor overall survival. Consistently, continuous treatment of MM cell lines with carfilzomib (CFZ) enhanced SUMO pathway activity. Treatment of MM cell lines with the SUMO E1-activating enzyme inhibitor subasumstat (TAK-981) showed synergy with CFZ in both CFZ-sensitive and CFZ-resistant MM cell lines, irrespective of the TP53 state. Combination therapy was effective in primary MM cells and in 2 murine MM xenograft models. Mechanistically, combination treatment with subasumstat and CFZ enhanced genotoxic and proteotoxic stress, and induced apoptosis was associated with activity of the prolyl isomerase PIN1. In summary, our findings reveal activated SUMOylation as a therapeutic target in MM and point to combined SUMO/proteasome inhibition as a novel and potent strategy for the treatment of proteasome inhibitor-resistant MM.

Relapse of NPM1-Mutated AML with Extramedullary Manifestation 17 Years after Allogeneic Hematopoietic Stem Cell Transplantation.

The majority of patients with acute myeloid leukemia (AML) with the NPM1 mutation achieve remission with intensive chemotherapy. However, many patients subsequently relapse, which occurs frequently within the first 2-3 years after therapy, while late relapse after more than 10 years is rare and can also represent secondary/therapy-associated AML without the NPM1 mutation. Here, we present a case of NPM1-mutated AML that developed medullary and extramedullary relapse 17 years after allogeneic stem cell transplantation, maintaining the NPM1 mutation and all other genetic alterations detected at first diagnosis. This exceptionally long latency between diagnosis and relapse of a genetically highly related leukemic clone implies the existence of therapy-resistant, persisting dormant leukemic stem cells in NPM1 mutant AML.

Personalized Treatment Selection and Disease Monitoring Using Circulating Tumor DNA Profiling in Real-World Cancer Patient Management.

BACKGROUND: Circulating tumor DNA (ctDNA) in the blood plasma of cancer patients is an emerging biomarker used across oncology, facilitating noninvasive disease monitoring and genetic profiling at various disease milestones. Digital droplet PCR (ddPCR) technologies have demonstrated high sensitivity and specificity for robust ctDNA detection at relatively low costs. Yet, their value for ctDNA-based management of a broad population of cancer patients beyond clinical trials remains elusive. METHODS: We developed mutation-specific ddPCR assays that were optimized for their use in real-world cancer management, covering 12 genetic aberrations in common cancer genes, such as EGFR, BRAF, KIT, KRAS, and NRAS. We assessed the limit of detection (LOD) and the limit of blank (LOB) for each assay and validated their performance for ctDNA detection using matched tumor sequencing. RESULTS: We applied our custom ddPCR assays to 352 plasma samples from 96 patients with solid tumors. Mutation detection in plasma was highly concordant with tumor sequencing, demonstrating high sensitivity and specificity across all assays. In 20 cases, radiographic cancer progression was mirrored by an increase of ctDNA concentrations or the occurrence of novel mutations in plasma. Moreover, ctDNA profiling at diagnosis and during disease progression reflected personalized treatment selection through the identification of actionable gene targets in 20 cases. CONCLUSION: Collectively, our work highlights the potential of ctDNA assessment by sensitive ddPCR for accurate disease monitoring, robust identification of resistance mutations, and upfront treatment selection in patients with solid tumors. We envision an increasing future role for ctDNA profiling within personalized cancer management in daily clinical routine.

Circulating Tumor DNA Allows Early Treatment Monitoring in BRAF- and NRAS-Mutant Malignant Melanoma.

PURPOSE: We evaluated circulating tumor DNA (ctDNA) for detecting tumor burden in melanoma and examined whether early changes in the number of ctDNA copies predict response to treatment. PATIENTS AND METHODS: We included 12 patients with stage III and 50 patients with stage IV melanoma with BRAF exon 15 or NRAS exon 3 mutations in tumor tissue. We used droplet digital polymerase chain reaction to retrospectively analyze serial plasma samples for mutation-positive ctDNA. RESULTS: Matched plasma and serum samples were positive for ctDNA, lactate dehydrogenase, and S100 in 113 (45.8%), 108 (43.7%; not significant), and 58 (23.5%; P < .0001) of 247 samples from 50 patients with stage IV melanoma, and in 17 (63%), eight (29.6%; P = .014), and five (18.5%; P < .0001) of 27 samples from 12 patients with stage III melanoma. The number of mutant ctDNA copies correlated with concentrations of lactate dehydrogenase (r = 0.50) and S100 (r = 0.64), tumor volume (r2 = 0.58), and tumor metabolic activity (r2 = 0.83). Within 30 days before surgery, initiation of treatment, or change in treatment, ctDNA, LDH, and S100 were positive in 76.8%, 53.6% (P = .01), and 46.4% (P < .001) of patients, respectively. In patients with stage III or IV melanoma, early changes in ctDNA within 1 month after initiation of treatment correctly predicted RECIST response categories in 19 of 20 patients. Detectable ctDNA within 30 days after surgery or initiation of systemic treatment predicted inferior progression-free survival in patients with stage III disease (P = .018). In patients with stage IV disease, 10 or more copies of ctDNA per mL at first follow-up indicated shorter progression-free survival (3.8 v 9 months; hazard ratio, 4.05; 95% CI, 1.56 to 10.53). CONCLUSION: ctDNA indicated active tumor and was an adverse prognostic marker for tumor progression. Dynamic changes in ctDNA allowed prediction of response early after initiation of treatment. These data support the use of ctDNA to guide treatment in melanoma.