Integrative Proteomic Analysis Implicates Inhibition of Intracellular Protein Trafficking in Therapy-Induced Migrastasis in Prostate Cancer

NTMT1 (METTL11A) promotes MYC-dependent proliferation and downstream HLA-A suppression in cervical cancer

Background Identifying upstream molecular regulators linking tumor proliferation with immune-related alterations remains an important challenge in cancer therapy. NTMT1 (METTL11A), a protein N-terminal methyltransferase, has been implicated in tumorigenesis; however, its role in coordinating tumor–immune interaction is poorly understood. Methods We performed integrative single-cell RNA sequencing (GSE208653) and spatial transcriptomics (GSE208654) analyses to characterize NTMT1 expression and function in cervical cancer. Spatial deconvolution and microenvironmental co-localization analyses were used to define context-specific effects. Functional validation was conducted using RT–qPCR, Western blotting, multiplex immunofluorescence, and flow cytometry-based assays. Results NTMT1 exhibited heterogeneous expression across epithelial and immune cell populations, with enrichment in squamous cell carcinoma. Spatial transcriptomics revealed that NTMT1-positive regions were associated with altered immune composition, including reduced macrophage and increased NK/T cell infiltration. In epithelial-enriched regions, NTMT1 expression correlated with activation of cell cycle pathways, including MYC, E2F1, CDK1, and CCNB1. Functional experiments demonstrated that NTMT1 promotes cell cycle progression via MYC upregulation. In epithelial–NK/T co-localization niches, NTMT1 was associated with modulation of antigen presentation pathways and suppression of HLA-A expression. Functionally, NTMT1 overexpression reduced IFN-γ production by CD8+ T cells under the co-culture conditions used in this study, which was partially restored by HLA-A re-expression. Conclusion NTMT1 was identified as a candidate regulator associated with MYC activation and HLA-A suppression. Although the precise molecular mechanism remains to be elucidated, functional experiments demonstrated that NTMT1 overexpression was accompanied by increased MYC expression, reduced HLA-A expression, enhanced cell-cycle progression, and impaired CD8+ T-cell function. These findings identify NTMT1 as a candidate regulatory node associated with MYC activation and downstream HLA-A suppression, warranting further mechanistic and in-vivo investigation, highlighting NTMT1 as a promising candidate for future therapeutic investigation. Further in vivo studies will be required to determine its suitability as a target for combination immunotherapy.

FBXW7 suppresses gastric cancer development and progression via ubiquitination-mediated degradation of MMP2

Background Gastric cancer (GC) remains a major cause of cancer-related mortality, highlighting the need to clarify the stromal and post-translational mechanisms underlying its progression. Methods We integrated single-cell RNA sequencing, independent transcriptomic cohorts, clinical tissue analyses, functional assays, co-immunoprecipitation (Co-IP), multiple immunofluorescence labeling, and a xenograft model to investigate the cellular distribution, biological function, and mechanisms of regulation for matrix metalloproteinase 2 (MMP2) in GC. Results Single-cell analysis of paired tumor and adjacent normal tissues suggested an increased relative abundance of fibroblast populations and higher extracellular matrix-associated activity in GC tissues. MMP2 was preferentially expressed in cancer-associated fibroblasts, particularly in transcriptionally defined universal fibroblast-like and myofibroblastic CAF states. Trajectory analysis further suggested that the MMP2-high universal fibroblast-like population occupies an early and potentially transitional position along the fibroblast-state continuum. These findings were supported by an independent single-cell dataset, TCGA-STAD analysis, and tissue staining. In CAF–gastric cancer cell co-culture assays, CAFs enhanced tumor-cell migration and invasion, while modulation of the FBXW7–MMP2 axis altered these phenotypes. MMP2 overexpression promoted GC cell proliferation, migration, and invasion, whereas MMP2 silencing had the opposite effects. Mechanistically, FBXW7 interacted with the intracellular pool of MMP2, enhanced its K48-linked polyubiquitination, and reduced MMP2 protein stability through a proteasome-dependent process. FBXW7 overexpression attenuated MMP2-associated malignant phenotypes in vitro and restrained MMP2-driven tumor growth in vivo. Clinical tissue analyses further showed an inverse association between FBXW7 and MMP2 expression, while elevated MMP2 was associated with unfavorable survival. Conclusion Our findings identify MMP2-high fibroblast states as an important stromal feature of GC and reveal FBXW7-associated regulation of intracellular MMP2 stability as a potential therapeutic vulnerability.

YBX1-mediated m5C modification of exosomal LGALS3 derived from M2 tumor-associated macrophages drives colorectal cancer cell malignant behaviors.

EMT activates ER-to-Golgi trafficking through upregulation of REEP2 to promote lung cancer progression

Membrane trafficking governs the transport of molecules to both intracellular and extracellular locations, thereby maintaining cell homeostasis. During cancer progression, alterations in membrane trafficking are frequently observed. However, the mechanisms underlying the dysregulation of membrane trafficking in cancer progression remain largely unresolved. Recent evidence has demonstrated that epithelial-to-mesenchymal transition (EMT) in lung adenocarcinoma (LUAD) employs a membrane trafficking program to coordinate cancer cell invasion and immunosuppression in the tumor microenvironment (TME). To further dissect the pro-tumorigenic membrane trafficking program, here we conducted a CRISPR interference (CRISPRi) in vivo screen for membrane trafficking regulators in a syngeneic mouse model with a complete immune system. This screen identified REEP2, an endoplasmic reticulum (ER) shaping protein, as a novel regulator of the EMT-dependent membrane trafficking program, which is associated with a poor prognosis in LUAD patients and is required for LUAD metastasis in a syngeneic orthotopic LUAD mouse model. Mechanistically, the EMT activator ZEB1 upregulates REEP2 expression through miR-183- and miR-193a-mediated regulation that promotes the transportation of secretory cargoes from the ER exit site (ERES) to the Golgi, thereby augmenting the secretion of pro-tumorigenic factors. The REEP2-driven secretion promotes cancer cell proliferation, migration, and the infiltration of myeloid-derived suppressor cells (MDSCs) in the TME. These findings identify REEP2 as a critical mediator of the EMT-driven pro-metastatic membrane trafficking program, revealing a specific vulnerability in mesenchymal LUAD.

Integrated bulk, single-cell and spatial transcriptomic analyses identify KIFC1 as a driver of malignant progression in lung adenocarcinoma

FREM1 promotes anlotinib resistance in non-small cell lung cancer through regulation of extracellular matrix organization.

BACKGROUND Acquired resistance to anlotinib, a multi-targeted tyrosine kinase inhibitor, severely limits its long-term efficacy in non-small cell lung cancer (NSCLC). The extracellular matrix (ECM) is a critical component of the tumor microenvironment known to mediate drug resistance, but the key regulators within the ECM driving anlotinib resistance remain elusive. METHODS We performed a preliminary, exploratory transcriptomic analysis using a publicly available dataset to identify differentially expressed genes between anlotinib-resistant and wild-type NSCLC cells. Exploratory enrichment analysis suggested ECM organization as a potentially altered process, from which FREM1 was selected as a top candidate for further validation. Functional roles of FREM1 were investigated using siRNA knockdown in resistant cell lines, followed by CCK-8, EdU, flow cytometry, wound healing, and Transwell assays. Underlying mechanisms were probed via Western blot and immunofluorescence. RESULTS FREM1 was significantly upregulated in anlotinib-resistant cells. Its knockdown enhanced the anti-tumor effect of anlotinib in resistant cells, leading to reduced proliferation, migration, and invasion while promoting apoptosis. Mechanistically, silencing FREM1 potently reversed the anlotinib-induced suppression of key ECM components, including Collagen I, Collagen IV, Fibronectin, and Laminin α5. CONCLUSION Our study identifies FREM1 as a candidate mediator of anlotinib resistance in NSCLC via regulation of ECM remodeling. Targeting the FREM1-ECM axis subject to independent validation represents a promising strategy to overcome resistance.