Background: Our previous study has demonstrated that NAD(P)H: quinone oxidoreductase 1 (NQO1) is significantly upregulated in human liver cancer where it potentiates the apoptosis evasion of liver cancer cell. However, the underlying mechanisms of the oncogenic function of NQO1 in HCC have not been fully elucidated. Methods: Expression of NQO1, SIRT6, AKT and X-linked inhibitor of apoptosis protein (XIAP) protein were measured by western blotting and immunohistochemistry. Additionally, the interaction between NQO1 and potential proteins were determined by immunoprecipitation assays. Furthermore, the effect of NQO1 and SIRT6 on tumor growth was determined in cell model and orthotopic tumor implantation model. Results: We found that NQO1 overexpression in HCC enhanced SIRT6 protein stability via inhibiting ubiquitin-mediated 26S proteasome degradation. High level of SIRT6 reduced acetylation of AKT which resulted in increased phosphorylation and activity of AKT. Activated AKT subsequently phosphorylated anti-apoptotic protein XIAP at Ser87 which determined its protein stability. Reintroduction of SIRT6 or AKT efficiently rescued NQO1 knock-out-mediated inhibition of growth and induction of apoptosis. In orthotopic mouse model, NQO1 knock-out inhibited tumor growth and induced apoptosis while this effect was effectively rescued by SIRT6 overexpression or MG132 treatment partially. Conclusions: Collectively, these results reveal an oncogenic function of NQO1 in sustaining HCC cell proliferation through SIRT6/AKT/XIAP signaling pathway.

Purpose: This study aims to evaluate the therapeutic potential of tubeimoside I (TBMS1), a monomer compound extracted from the tubers of Chinese herb Bolbostemma paniculatum (Maxim). Franquet (Cucurbitaceae), in the treatment of liver cancer. Specifically, we sought to elucidate the underlying mechanisms through which TBMS1 exerts its anticancer effects. Methods: The effects of TBMS1 on the viability, proliferation, and apoptosis of two liver cancer cell lines, MHCC97-H and SNU-449, were comprehensively assessed using Cell Counting Kit-8 (CCK-8), colony formation, 5-ethynyl-2′-deoxyuridine (EDU) assay, and flow cytometry assays. To uncover the molecular mechanisms, RNA sequencing was performed to identify the downstream targets of TBMS1. Additionally, we utilized network pharmacology to predict TBMS1 targets in liver cancer and employed Venn diagram analysis to integrate these predictions with our experimental findings. Pathway enrichment analysis was conducted using Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) databases to elucidate the biological processes involved. Furthermore, a subcutaneous xenograft tumor model was established to investigate the in vivo antitumor efficacy of TBMS1. Results: In vitro experiments demonstrated that TBMS1 significantly enhanced cell apoptosis and inhibited the growth of liver cancer cells. Both network pharmacology predictions and RNA-seq analyses revealed that the downstream target genes of TBMS1 were highly enriched in the NF-κB signaling pathway. Notably, we observed a significant upregulation of TNFα-induced protein 3 (TNFAIP3) expression with increasing concentrations of TBMS1. In vivo studies further confirmed that TBMS1 treatment dramatically reduced the volume and weight of liver cancer tumors compared to controls. Conclusion: Our study provides compelling evidence that TBMS1 suppresses liver cancer progression by inactivating the NF-κB pathway and regulating TNFAIP3 expression. These findings offer novel insights and a theoretical basis for the development of targeted therapies for liver cancer.

Background and Aims: Hepatocellular carcinoma (HCC) is a malignant tumour associated with high morbidity and mortality rates worldwide. Recently, TRPM8 was reported to play an important role in tumour progression. However, the precise role of TRPM8 in HCC remains unclear. In this study, we explored the expression levels, molecular functions and underlying mechanisms of TRPM8 in HCC.Methods: Tissue samples were used to analyse the expression of TRPM8 to assess its diagnostic value for prognosis. Cell Counting Kit‐8, EdU and colony formation assays were performed to evaluate the effects of TRPM8 on cell proliferation, whereas the Transwell assay was used to assess cell migration and invasion. The role of TRPM8 in vivo was evaluated using a mouse subcutaneous xenograft tumour model. We performed PPI network analyses to understand the possible mechanisms of TRPM8 action.Results: TRPM8 expression was decreased in HCC tissues and was correlated with histological grade and poor patient prognosis. Functionally, TRPM8 repressed the proliferation and metastasis of HCC cells both in vitro and in vivo by modulating the RTP3/STAT3 signalling pathway.Conclusion: Our findings underscore the critical role of the TRPM8‐RTP3‐STAT3 axis in maintaining the malignant progression of HCC. Moreover, our study demonstrates that AD80 is involved in anti‐tumour processes by upregulating the expression of TRPM8.