Acta Biochimica et Biophysica Sinica•2025•DOI: 10.3724/abbs.2025042
This study elucidates the mechanisms by which cancer-associated fibroblast (CAF)-derived platelet-derived growth factor C (PDGFC) promotes the progression of lung adenocarcinoma (LUAD) and explores the impact of PDGFC on immune regulation within the tumor microenvironment (TME). Our results show that there is higher expression of PDGFC in CAFs than in nontumor tissue fibroblasts (NFs) and that higher expression of PDGFC is correlated with poor prognosis in LUAD patients. Furthermore, CAF-derived PDGFC promotes epithelial-mesenchymal transition (EMT) in cancer cells as well as matrix metalloproteinase 2 (MMP2) expression through the PDGF receptor A (PDGFRA)-mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK) pathway. Moreover, our study demonstrates that CAF-derived PDGFC is essential for the activation and infiltration of fibroblasts in the TME, as well as the inflammatory infiltration of different immune cell types and the immunosuppressive conditions within the TME. In particular, PDGFC induces increased PDGFRA expression in both tumor cells and fibroblasts, which can lead to reciprocally positive feedback to accelerate malignant tumor progression. This discovery provides a novel TME-targeted strategy for LUAD treatment.
Acta Biochimica et Biophysica Sinica•2025•DOI: 10.3724/abbs.2025017
Studies of cell-to-cell activities in the tumor microenvironment (TME) have identified multiple potential targets for oncotherapy. The interplay between tumor cells and neighboring cancer-associated fibroblasts (CAFs) persists in all stages of tumor progression. In this study, we reveal that exosomes from breast cancer cells can be endocytosed into fibroblasts and transform normal fibroblasts (NFs) into CAFs and that the ability of exosomes from highly metastatic breast cancer cells is greater than that of those from poorly metastatic breast cancer cells. Further investigation reveals that exosomes from highly metastatic breast cancer cells contain much more miR-105-5p than those from poorly metastatic breast cells do and that exosomal miR-105-5p facilitates the transformation of NFs to CAFs. A detailed study reveals that RBMY1A1-dependent sorting of miR-105-5p into fibroblasts and subsequent internalization of miR-105-5p promote the transformation of NFs to CAFs by downregulating LATS2 expression and activating NF-κB signaling, which concurrently facilitates the EMT of breast cancer cells. Thus, our results indicate that exosomal miR-105-5p may be a potential target for novel therapeutic strategies to prevent the coevolution of breast cancer cells and CAFs.
Acta Biochimica et Biophysica Sinica•2025•DOI: 10.3724/abbs.2024168
Uncoupling protein-2 (UCP2) controls the antioxidant response and redox homeostasis in cancer and is considered a potent molecular target for cancer treatment. However, the specific mechanism of UCP2 inhibition and its role in glioblastoma (GBM) have not yet been elucidated. Here, we attempt to identify a UCP2 inhibitor and study the underlying molecular mechanism in GBM. Bioinformatics analysis and immunohistochemistry are used to validate the high expression of UCP2 in GBM and its prognostic significance. Drug intervention and tumor xenograft experiments are conducted to determine the inhibitory effect of genipin, a UCP2 inhibitor, on UCP2. The mitochondrial membrane potential and key ferroptosis genes are examined to determine the occurrence of ferroptosis. High expression of UCP2 in GBM is associated with poor prognosis, and inhibiting UCP2 can alleviate the malignant behavior of GBM tumors. Genipin can downregulate the expression of GPX4 and upregulate the expression of ACSL4 by inhibiting UCP2, leading to ferroptosis and alleviating the malignant behavior of tumors. In summary, UCP2 is a potential therapeutic target for GBM. Genipin, which targets UCP2, effectively inhibits GBM development by inducing ferroptosis in vivo and in vitro. These findings indicate that genipin treatment based on UCP2 targeting has potential therapeutic applications with a clinical perspective for the treatment of GBM patients.
Acta Biochimica et Biophysica Sinica•2025•DOI: 10.3724/abbs.2025042
Lung adenocarcinoma (LUAD) remains a leading cause of cancer-related mortality, with late-stage 5-year survival rates below 50%. Cancer-associated fibroblasts (CAFs) within the tumor microenvironment (TME) drive progression, yet the molecular mediators of CAF-tumor crosstalk are incompletely defined. This study identifies platelet-derived growth factor C (PDGFC) as a critical CAF-secreted factor that promotes epithelial-mesenchymal transition (EMT) and immunosuppression in LUAD. Analysis of patient specimens revealed elevated PDGFC expression in CAFs relative to nontumor tissue fibroblasts (NFs), and high PDGFC levels correlated with poor prognosis. Mechanistically, CAF-derived PDGFC activates the PDGF receptor A (PDGFRA)-mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK) pathway in cancer cells, inducing EMT and matrix metalloproteinase 2 (MMP2) expression. PDGFC also stimulates PDGFRA expression in both tumor cells and fibroblasts, establishing a reciprocal positive feedback loop that accelerates fibrotic TME remodeling and malignant progression. Immunologically, PDGFC promotes infiltration and polarization of immunosuppressive cell populations, including CD4+ Treg cells, M2 macrophages, and N2 neutrophils, while restraining immunocompetent NK cells. Immunoinhibitors TGFB1, CSF1R, PD-L1, PD-L2, KDR, IL10RB, and HAVCR2 may synergize with PDGFC in modulating immunosuppression. These findings position PDGFC as a diagnostic indicator and potential immunotherapy target for LUAD, offering a novel TME-targeted therapeutic strategy.