Cancer research最新文献

Tumor-associated macrophages (TAM) are a heterogeneous population of myeloid cells that dictate the inflammatory tone of the tumor microenvironment. In this study, we unveiled a mechanism by which scavenger receptor cluster of differentiation 36 (CD36) suppresses TAM inflammatory states. CD36 was upregulated in TAMs and associated with immunosuppressive features, and myeloid-specific deletion of CD36 significantly reduced tumor growth. Moreover, CD36-deficient TAMs acquired inflammatory signatures including elevated type-I IFN (IFNI) production, mirroring the inverse correlation between CD36 and IFNI response observed in patients with cancer. IFNI, especially IFNβ, produced by CD36-deficient TAMs directly induced tumor cell quiescence and delayed tumor growth. Mechanistically, CD36 acted as a natural suppressor of IFNI signaling in macrophages through p38 activation downstream of oxidized lipid signaling. These findings establish CD36 as a critical regulator of TAM function and the tumor inflammatory microenvironment, providing additional rationale for pharmacologic inhibition of CD36 to rejuvenate antitumor immunity. Significance: CD36 in tumor-associated macrophages mediates immunosuppression and can be targeted as a therapeutic avenue for stimulating interferon production and increasing the efficacy of immunotherapy.

Internal tandem duplication (ITD) in the FMS-like receptor tyrosine kinase-3 (FLT3) is one of the most frequent mutations in acute myeloid leukemia (AML) and is associated with poor prognosis. FLT3-ITD mutations result in endoplasmic reticulum (ER) retention and constitutive autophosphorylation of FLT3. The PR/SET domain 16 (PRDM16) is highly expressed in patients with FLT3-ITD+ AML, suggesting it might play a role in leukemogenesis. Here, we revealed that genetic and pharmacologic suppression of PRDM16 greatly slowed the progression of FLT3-ITD-driven leukemia, sensitized leukemic cells to tyrosine kinase inhibitors, and extended the survival of leukemic mice. PRDM16 enhanced activation of oncogenic FLT3-ITD and ligand-dependent activation of wild-type FLT3 in leukemic cells. Mechanistically, PRDM16 mediated monomethylation of FLT3-ITD at lysine-614 and promoted its ER localization, resulting in enhanced FLT3 signaling in leukemia cells. Moreover, pharmacologic suppression of FLT3-ITD methylation in combination with tyrosine kinase inhibitors increased the elimination of FLT3-ITD+ AML cells. Altogether, these results suggest that PRDM16 boosts oncogenic FLT3 signaling in leukemic cells by prompting FLT3-ITD methylation. Therefore, PRDM16 may serve as a therapeutic target for AML. Significance: Monomethylation of FLT3-ITD at lysine-614 by PRDM16 induces FLT3 ER localization and enhanced signaling, which can be inhibited by targeting PRDM16 to suppress survival of FLT3-ITD+ AML cells and increase chemosensitivity.

During metastasis, cancer cells detach from the primary tumor, circulate through the bloodstream, and establish themselves at distant sites, facing increased levels of reactive oxygen species that act as significant barriers to metastatic progression. Adapting to and surviving in these high reactive oxygen species environments are thus crucial for successful metastasis. A recent study by Nease and colleagues identified FTSJ1 as the methyltransferase responsible for methylation of the U34 position wobble uridine modification of selenocysteine (Sec) tRNA. This methylation enables efficient Sec insertion, leading to increased translation of a subset of stress-responsive selenoproteins that combat the oxidative stress encountered during the metastatic process. This study establishes FTSJ1 as an essential redox regulator during metastasis through its role in enhancing Sec insertion efficiency and introduces a potential therapeutic strategy against metastasis.

Fungal dysbiosis is increasingly recognized as a key factor in cancer, influencing tumor initiation, progression, and treatment outcomes. This review explores the role of fungi in carcinogenesis, with a focus on mechanisms such as immunomodulation, inflammation induction, tumor microenvironment remodeling, and interkingdom interactions. Fungal metabolites are involved in oncogenesis, and antifungals can interact with anticancer drugs, including eliciting potential adverse effects and influencing immune responses. Furthermore, mycobiota profiles have potential as diagnostic and prognostic biomarkers, emphasizing their clinical relevance. The interplay between fungi and cancer therapies can affect drug resistance, therapeutic efficacy, and risk of invasive fungal infections associated with targeted therapies. Finally, emerging strategies for modulating mycobiota in cancer care are promising approaches to improve patient outcomes.

Three-dimensional (3D) in vitro cell culture models are invaluable tools for investigating the tumor microenvironment (TME). However, analyzing the impact of critical stromal elements, such as extracellular matrix (ECM), remains a challenge. Here, we developed a hydrogel-free self-assembly platform to establish ECM-rich 3D "MatriSpheres" to deconvolute cancer cell-ECM interactions. Mouse and human colorectal cancer (CRC) MatriSpheres actively incorporated microgram quantities of decellularized small intestine submucosa ECM, which proteomically-mimicked CRC tumor ECM compared to traditional formulations like Matrigel. Solubilized ECM, at sub-gelation concentrations, was organized by CRC cells into intercellular stroma-like regions within 5 days, displaying morphological similarity to CRC clinical pathology. MatriSpheres featured ECM-dependent transcriptional and cytokine profiles associated with malignancy, lipid metabolism, and immunoregulation. Model benchmarking with scRNA sequencing demonstrated that MatriSpheres enhanced correlation with in vivo tumor cells over traditional ECM-poor spheroids. This facile approach enables tumor-specific tissue morphogenesis, promoting cell-ECM communication to improve fidelity for disease modeling applications.