Qiulei Wu

LEF1 confers resistance to DNA-damaging chemotherapies through upregulation of PARP1 and NUMA1 in ovarian cancer

Resistance to platinum-based drugs and PARP inhibitors (PARPi) is the leading cause of treatment failure in epithelial ovarian cancer (EOC). This study aimed to identify resistance mechanisms shared by both. Using bioinformatic analyses, EOC tissues, primary tumor cells and organoids, and chemoresistant cell lines, we identified lymphoid enhancer-binding factor 1 (LEF1) as a candidate, whose expression was increased in both platinum-resistant and PARPi-resistant tumors. Moreover, LEF1 deficiency increased EOC cell sensitivity to cisplatin and PARPi in vitro and in vivo. Mechanistically, LEF1 knockdown promoted double-strand breaks and significantly impaired both homologous recombination and nonhomologous end joining by directly downregulating the transcription of PARP1 and NUMA1. In addition, the LEF1 inhibitor niclosamide increased ovarian cancer sensitivity to Cisplatin and PARPi in patient-derived organoids and Niraparib-resistant cell lines. These findings indicate that LEF1 is a potential therapeutic target for overcoming resistance to chemotherapy based on platinum and PARPi in EOC.

Extracellular vesicles from ovarian cancer cells induce senescent lipid-laden macrophages to facilitate omental metastasis

Ovarian cancer exhibits striking metastatic tropism for the omentum, where lipid-laden macrophages are key mediators that fuel disease progression. However, the mechanisms governing their formation and pro-metastatic functions remain poorly understood. As extracellular vesicles (EVs) have as critical regulators of tumor-stroma crosstalk in metastatic niches, we sought to define how ovarian cancer-derived EVs orchestrate macrophages and adipocytes, and their impact on omental metastasis, aiming to explore potential therapeutic interventions. Single-cell transcriptomics of ovarian cancer revealed a distinct lipid-laden macrophage population in omentum, whose abundance correlated with metastatic burden and poor survival. Proteomics revealed that EVs from highly metastatic ovarian cancer cells were enriched in lipid metabolism regulators. In vivo experiments demonstrated that these tumor-derived vesicles mediated macrophage reprogramming, driving the acquisition of a pro-metastatic phenotype. Quantitative lipidomic profiling and lipid staining approaches confirmed the progressive lipid-laden in EV-treated macrophages. Using a patient-derived omentum-macrophage co-culture system, we demonstrated that tumor-derived EVs stimulate lipid release from omental adipocytes, which macrophages subsequently internalize through CD36-dependent uptake to drive lipid accumulation. This metabolic reprogramming culminated in cellular senescence, as evidenced by classical biomarkers including SA-β-galactosidase activity, elevated p16-INK4A and p53 levels, and the development of a matrix metalloproteinase-enriched senescence-associated secretory phenotype. Immunohistochemistry of clinical specimens demonstrated overexpression of CD36 correlated with omental metastasis and poor survival in ovarian cancer. In vivo experiments demonstrated that CD36 inhibition and senolytic therapy attenuated omental metastasis. This study unveils an EV-driven mechanism of adipose tropism in ovarian cancer metastasis, where EVs promote the formation of senescent lipid-laden macrophages via CD36-mediated lipid uptake, remodeling the metastatic niche. Targeting CD36 and senescent cells offers a promising therapeutic strategy against omental metastasis.

Tumour-derived exosomal piR-25783 promotes omental metastasis of ovarian carcinoma by inducing the fibroblast to myofibroblast transition

Ovarian carcinoma inherently possesses a distinct metastatic organotropism for the adipose-rich omentum, contributing to disease progression. Although the premetastatic microenvironment (PMM) has been known to often play a prometastatic role during the process, incomplete mechanistic insight into PMM formation has prevented its therapeutic targeting. Omental fibroblasts can be activated by tumour cells to differentiate into myofibroblasts, termed the fibroblast-to-myofibroblast transition (FMT), which, in turn, enhances cancer aggressiveness. Here, we report crosstalk between cancer cells and omental fibroblasts through exosomal piR-25783, which fuels tumour metastasis. Tumour cell-secreted exosomal piR-25783 activates the TGF-β/SMAD2/SMAD3 pathway in fibroblasts and promotes the FMT in the omentum along with the secretion of various cytokines and elevation of proliferative, migratory, and invasive properties, contributing to the formation of PMMs. Furthermore, piR-25783-induced myofibroblasts promote tumour implantation and growth in the omentum. In addition, the overexpression of piR-25783 in ovarian carcinoma is associated with unfavourable clinicopathological characteristics and shorter survival. In this study, we provide molecular, functional, and translational evidence suggesting that exosomal piR-25783 plays an important role in the formation of PMMs and the development of metastatic diseases in vitro and in vivo and may serve as a potential therapeutic target for ovarian carcinoma with metastasis.