Merkel cell polyomavirus pan-T antigen knockdown reduces cancer cell stemness and promotes neural differentiation independent of RB1.

Merkel cell carcinoma (MCC) is a highly aggressive skin cancer associated with integration of Merkel cell polyomavirus (MCPyV). MCPyV-encoded T-antigens (TAs) are pivotal for sustaining MCC's oncogenic phenotype, i.e.

Mesenchymal-epithelial transition in lymph node metastases of oral squamous cell carcinoma is accompanied by ZEB1 expression.

Background: Oral squamous cell carcinoma (OSCC), an HPV-negative head and neck cancer, frequently metastasizes to the regional lymph nodes but only occasionally beyond. Initial phases of metastasis are associated with an epithelial-mesenchymal transition (EMT), while the consolidation phase is associated with mesenchymal-epithelial transition (MET). This dynamic is referred to as epithelial-mesenchymal plasticity (EMP).

Phenotypic plasticity of malignant T cells in blood and skin of a Sézary syndrome patient revealed by single cell transcriptomics.

Background: Sézary Syndrome (SS) is an aggressive leukemic variant of cutaneous T-cell lymphomas (CTCL). In SS patients, malignant T cells are circulating through the blood and cause erythroderma.

Objective: To compare the transcriptome of single cells in blood and skin samples from a patient with advanced SS.

Tumor-infiltrating mast cells are associated with resistance to anti-PD-1 therapy.

Anti-PD-1 therapy is used as a front-line treatment for many cancers, but mechanistic insight into this therapy resistance is still lacking. Here we generate a humanized (Hu)-mouse melanoma model by injecting fetal liver-derived CD34 cells and implanting autologous thymus in immune-deficient NOD-scid IL2Rγ (NSG) mice. Reconstituted Hu-mice are challenged with HLA-matched melanomas and treated with anti-PD-1, which results in restricted tumor growth but not complete regression.

BRAF and MEK inhibition in melanoma patients enables reprogramming of tumor infiltrating lymphocytes.

Background: Combined inhibition of BRAF/MEK is an established therapy for melanoma. In addition to its canonical mode of action, effects of BRAF/MEK inhibitors on antitumor immune responses are emerging. Thus, we investigated the effect of these on adaptive immune responses.

Predominance of Central Memory T Cells with High T-Cell Receptor Repertoire Diversity is Associated with Response to PD-1/PD-L1 Inhibition in Merkel Cell Carcinoma.

Purpose: Merkel cell carcinoma (MCC) is an aggressive neuroendocrine skin cancer, which can be effectively controlled by immunotherapy with PD-1/PD-L1 checkpoint inhibitors. However, a significant proportion of patients are characterized by primary therapy resistance. Predictive biomarkers for response to immunotherapy are lacking.

Antibiotics inhibit tumor and disease activity in cutaneous T-cell lymphoma.

It has been proposed that CD4 T-cell responses to (SA) can inadvertently enhance neoplastic progression in models of skin cancer and cutaneous T-cell lymphoma (CTCL). In this prospective study, we explored the effect of transient antibiotic treatment on tumor cells and disease activity in 8 patients with advanced-stage CTCL. All patients experienced significant decrease in clinical symptoms in response to aggressive, transient antibiotic treatment.

The Potency of Nef-Mediated SERINC5 Antagonism Correlates with the Prevalence of Primate Lentiviruses in the Wild.

The cellular factor serine incorporator 5 (SERINC5) impairs HIV-1 infectivity but is antagonized by the viral Nef protein. We analyzed the anti-SERINC5 activity of Nef proteins across primate lentiviruses and examined whether SERINC5 represents a barrier to cross-species transmissions and/or within-species viral spread. HIV-1, HIV-2, and SIV Nefs counteract human, ape, monkey, and murine SERINC5 orthologs with similar potency.

Trichostatin A effectively induces apoptosis in chronic lymphocytic leukemia cells via inhibition of Wnt signaling and histone deacetylation.

Background: The ontogenetic Wnt pathway shows almost no activity in adult tissues. In contrast, chronic lymphocytic leukemia (CLL) cells show constitutionally active Wnt signaling, which is associated with upregulated levels of pathway members such as Wnt3 and lymphoid enhancer-binding factor-1. Functionally, this results in increased resistance to apoptosis.