Cancer research最新文献

Genomic alterations affecting components of the fibroblast growth factor (FGF) signaling axis can trigger aberrant pathway activation and tumor development. Genomic truncation of the FGF receptor 2 (FGFR2) exon 18 (E18) disrupts the FGFR2 carboxy (C)-terminal tail, acting as a potent driver alteration across multiple tumor types. In this study, we analyzed human oncogenomic datasets to reveal that E18 truncations are similarly prevalent in FGFR3, an FGFR2 paralog. FGFR3 E18 truncations primarily occur due to rearrangements (RE) that involve transforming acidic coiled-coil-containing protein 3 (TACC3), resulting in FGFR3ΔE18-TACC3 gene fusions. In contrast to E18-truncated FGFR2, functional in vitro and in vivo examination of Fgfr3 variants demonstrated that the truncation of Fgfr3 E18 is insufficient to promote oncogenic activity in cell lines or in the lungs and mammary glands of mice. Only the combination of an Fgfr3 E18 truncation with a RE partner gene that encodes a receptor-dimerizing domain resulted in the development of tumors, which were sensitive to FGFR inhibition. Overall, these findings suggest that patients with cancers that are positive for rearranged FGFR3, resulting in E18 truncation and a fusion to dimerizing partners, should be considered for FGFR-targeted therapies.

Significance: FGFR3, unlike its paralog FGFR2, requires both a C-terminal truncation and fusion to a partner gene that retains the expression of a dimerizing domain to effectively drive oncogenic signaling and tumorigenesis.

Peripheral nerve invasion (PNI) is an early and decisive step in gallbladder cancer progression that strongly predicts poor postsurgical outcome. The tumor-neuron interactions that drive PNI could represent potential targets and biomarkers to improve treatment of gallbladder cancer. In this study, we demonstrated that gallbladder cancer provoked necroptosis of neurons to enable PNI. Gallbladder cancer cells transferred extracellular vesicles (EV) containing O-GlcNAcase (OGA) to neurons, which activated RIPK1-dependent necroptosis. Mechanistically, EV-derived OGA suppressed RIPK1 glycosylation while enhancing its phosphorylation, thereby activating the RIPK1/RIPK3/MLKL axis to trigger neuronal necroptosis. Subsequent neuronal release of HMGB1 engaged RAGE on gallbladder cancer cells, establishing a loop that accelerated PNI. Moreover, the RAGE antagonist FPS-ZM1 synergized with gemcitabine to suppress tumor progression. Collectively, these findings uncover an EV-mediated cross-talk between gallbladder cancer cells and neurons in which RIPK1-dependent necroptosis and its effector HMGB1 drive PNI, positioning the HMGB1-RAGE axis as a tractable therapeutic target.

Significance: Tumor-derived extracellular vesicles trigger neuronal necroptosis that fuels peripheral nerve invasion, creating a tumor-neuron signaling loop that could be leveraged for liquid biopsy and personalized therapy strategies in neurotropic cancers.

Cancer-associated fibroblasts (CAFs) exhibit phenotypic heterogeneity with each functional state playing critical roles in tumor progression. Notably, subtypes like inflammatory CAFs (iCAFs), characterized by increased chemokine/cytokine secretion, and myofibroblast-like CAFs (myCAFs), characterized by enhanced extracellular matrix (ECM) deposition and increased actomyosin contractility, can undergo phenotypic switching in response to cues from the tumor microenvironment (TME) and therapeutic interventions. Elucidation of the signaling pathways associated with the diverse phenotypes could enable development of strategies to therapeutically reprogram CAFs. Through the analysis of single-cell RNA sequencing data from colorectal cancer (CRC) patients, we identified that the PI3K/mTOR and MAPK/ERK signaling pathways, among other pathways, are linked to the formation of myCAF and iCAF subtypes, respectively. Unbiased pharmacological interference of 12 distinct signaling pathways using three-dimensional (3D) human CRC-derived CAF cultures, ex vivo patient-derived tumor fragments, and mouse models further revealed the significance of PI3K/mTOR and MAPK/ERK signaling in CAF plasticity and functional behavior. PI3K/mTOR inhibition drove iCAF formation through compensatory FGF-2 release and FGFR1-JAK2-STAT3 activation, leading to chemokine/cytokine secretion that promoted tumor spheroid growth and neutrophil infiltration. Conversely, MEK inhibition induced a myCAF phenotype via interferon-dependent ROCK and JAK1 signaling, resulting in ECM production that enhanced tumor colony formation. In summary, these findings reveal a functional significance of PI3K/mTOR and MAPK/ERK signaling pathways in CAF plasticity and underscore how standard-of-care targeted therapies can directly influence CAF phenotypes in CRC.

The basal-like molecular subtype of pancreatic ductal adenocarcinoma (PDAC) is highly lethal and therapy resistant. A better understanding of the underlying molecular mechanisms driving this aggressive tumor subtype is necessary for the development of effective therapies. Notably, upregulation of keratin 17 (K17) in cancer is associated with poor patient outcome and the basal-like PDAC subtype. Here, we identified a critical dependency of basal-like PDACs on de novo pyrimidine biosynthesis, driven by intra-mitochondrial K17. Mechanistically, K17 translocated into the mitochondrial intermembrane space via a mitochondrial localization sequence (MLS) recognized by the translocase of the outer mitochondrial membrane 20 (TOM20). In the mitochondria, K17 bound to and stabilized dihydroorotate dehydrogenase (DHODH), the rate-limiting enzyme of de novo pyrimidine biosynthesis, by preventing its ubiquitination-mediated degradation. Blocking the entry of K17 into the mitochondria sensitized cancer cells to gemcitabine, a pyrimidine analog and standard chemotherapeutic agent. In animal studies, pharmacologic inhibition of DHODH combined with gemcitabine treatment decreased tumor growth and doubled survival in mice bearing K17⁺ but not K17⁻ PDAC. These findings define a mitochondrial role for K17 in driving pyrimidine biosynthesis and uncover a metabolic vulnerability in K17⁺ basal-like PDACs that can be therapeutically targeted.

Chimeric antigen receptor T (CAR-T) cell therapy is revolutionizing cancer treatment in hematological malignancies, but challenges related to the tumor microenvironment have hindered CAR-T success, especially in solid tumors. Myeloid cells in particular have been implicated in CAR-T efficacy. In this review, we discuss the roles of myeloid cells in CAR-T-associated toxicities including cytokine release syndrome, immune effector cell-associated neurotoxicity syndrome, and immune effector cell-associated hemophagocytic lymphohistiocytosis-like syndrome, along with strategies to treat these toxicities by modulating myeloid cells. The review also explores myeloid cell-mediated suppression or enhancement of CAR-T function. Finally, strategies employed to target myeloid cells in combination with CAR-T cell therapy will be investigated.