Senescent cancer cells often evade immune clearance to exert profound effects on cancer progression and therapy resistance. Improving immunosurveillance to eliminate senescent cancer cells is a crucial measure to enhance anti-cancer therapy. Bazi Bushen (BZBS) is a traditional medicine with the function of relieving fatigue and delaying ageing, but its role in tumor treatment remains poorly understood. Herein, we find that BZBS promotes immunosurveillance of both chemotherapy- and oncogene-induced senescent liver cancer cells, further leading to enhanced chemotherapy efficacy and dramatic tumor repression in mice. Mechanistically, BZBS induces mitochondrial DNA leakage by mitochondrial damage to further activate cGAS-STING signaling in macrophages. Subsequently, cGAS-STING signaling activation in macrophages recruits CD8+ T cells into tumor and promotes the anti-tumor activity of CD8+ T cells to eradicate senescent cancer cells. Furthermore, host STING is responsible for BZBS-mediated immunosurveillance of senescent liver cancer cells in mice. Therefore, our findings unveil the role of traditional medicine BZBS in activating cGAS-STING signaling and potentiating senescence immunosurveillance to enhance anti-cancer therapy.
Esophageal squamous cell carcinoma (ESCC) is one of the most prevalent cancers worldwide, characterized by a dismal prognosis and elusive therapeutic targets. Dysregulated cholesterol metabolism is a critical hallmark of cancer cells, facilitating tumor progression. Here, using whole genome sequencing data from several ESCC cohorts, we identified the important role of squalene epoxidase (SQLE) in promoting ESCC tumorigenesis and metastasis. Specifically, our findings highlight the significance of 2,3-oxidosqualene, an intermediate metabolite of cholesterol biosynthesis, synthesized by SQLE and metabolized by lanosterol synthase (LSS), as a key regulator of ESCC progression. Mechanistically, the interaction between 2,3-oxidosqualene and vinculin enhances the nuclear accumulation of Yes-associated protein 1 (YAP), thereby increasing YAP/TEAD-dependent gene expression, and accelerating both tumor growth and metastasis. In a 4-nitroquinoline 1-oxide (4-NQO)-induced ESCC mouse model, overexpression of Sqle resulted in accelerated tumorigenesis compared to wild-type controls, highlighting the pivotal role of SQLE in vivo. Furthermore, elevated SQLE expression in ESCC patients correlates with poorer prognoses, suggesting potential therapeutic avenues for ESCC treatment. In conclusion, our study elucidates the oncogenic function of 2,3-oxidosqualene as a naturally occurring metabolite and proposes modulation of its levels as a promising therapeutic strategy for ESCC.
Pyruvate Dehydrogenase Kinase 1 (PDK1) regulates glycolysis and oxidative phosphorylation pathways and is linked to prostate cancer metastasis and poor prognosis. The therapeutic application of 2,2-dichloroacetophenone (DAP), a PDK1 inhibitor, remains underexplored in prostate cancer. In this study we demonstrated that DAP exhibited a superior ability to inhibit prostate cancer cell proliferation, migration and colony formation at a lower concentration (20 μM) compared to a previously established inhibitor, dichloroacetate (DCA), which required concentrations of 30 mM or higher. However, poor aqueous solubility and lower stability of DAP limits its therapeutic application. Nano formulation of DAP with natural lactoferrin enhanced its dispersion and stability by increasing polydispersity index and intensity, and reduced zeta potential values upon conjugation that overcame the solubility limitations of DAP. The lactoferrin-DAP nanoparticles exhibited enhanced therapeutic efficacy by precisely targeting prostate cancer cells that express high lactoferrin receptors and high anti-tumor activity in vitro (at 1 μM) and in mouse prostate tumor xenografts (20 mg/kg). Mechanistically, these nanoparticles induce apoptosis in cancer cells by inducing caspase3/7 activity and disrupting the glycolytic and oxidative phosphorylation pathways. Moreover, lactoferrin-conjugated DAP nanoparticles suppressed the viability of docetaxel-resistant cells exhibiting a higher inhibitory efficacy compared to free DAP and DCA. Targeting PDK1 through lactoferrin-conjugated DAP nanoparticles represents a potent targeted therapeutic strategy for disrupting prostate tumor metabolism and offers promising implications for overcoming drug resistance.