3-methylquercetin and Liver-Neoplasms

The immune checkpoint inhibitor (ICI) anti-PD-L1 monoclonal antibody can inhibit the progress of hepatocellular carcinoma (HCC). Epithelial-mesenchymal transformation (EMT) can promote tumor migration and the formation of immune-suppression microenvironment, which affects the therapeutic effect of ICI. Yin-yang-1 (YY1) is an important transcription factor regulating proliferation, migration and EMT of tumor cells. This work proposed a drug-development strategy that combined the regulation of YY1-mediated tumor progression with ICIs for the treatment of HCC.. We first studied the proteins that regulated YY1 expression by using pull-down, co-immunoprecipitation, and duo-link assay. The active compound regulating YY1 content was screened by virtual screening and cell-function assay. Isorhamnetin (ISO) and anti-PD-L1 antibody dual-functional mesoporous silica nanoparticles (HMSN-ISO@ProA-PD-L1 Ab) were prepared as an antitumor drug to play a synergistic anti-tumor role.. YY1 can specifically bind with the deubiquitination enzyme USP7. USP7 can prevent YY1 from ubiquitin-dependent degradation and stabilize YY1 expression, which can promote the proliferation, migration and EMT of HCC cells. Isorhamnetin (ISO) were screened out, which can target USP7 and promote YY1 ubiquitin-dependent degradation. The cell experiments revealed that the HMSN-ISO@ProA-PD-L1 Ab nanoparticles can specifically target tumor cells and play a role in the controlled release of ISO. HMSN-ISO@ProA-PD-L1 Ab nanoparticles inhibited the growth of Hepa1-6 transplanted tumors and the effect was better than that of PD-L1 Ab treatment group and ISO treatment group. HMSN-ISO@ProA-PD-L1 Ab nanoparticles also exerted a promising effect on reducing MDSC content in the tumor microenvironment and promoting T-cell infiltration in tumors.. The isorhamnetin and anti-PD-L1 antibody dual-functional nanoparticles can improve tumor immune microenvironment and inhibit YY1-mediated tumor progression. This study demonstrated the possibility of HCC treatment strategies based on inhibiting USP7-mediated YY1 deubiquitination combined with anti-PD-L1 monoclonal Ab.

Topics: Carcinoma, Hepatocellular; Cell Line, Tumor; Hereditary Sensory and Motor Neuropathy; Humans; Liver Neoplasms; Tumor Microenvironment; Ubiquitin-Specific Peptidase 7; Ubiquitins; YY1 Transcription Factor

Topics: Antineoplastic Agents, Phytogenic; Carcinoma, Hepatocellular; Cell Movement; Cell Proliferation; Cleome; Flavonoids; Glycosides; Hep G2 Cells; Humans; Liver Neoplasms; MicroRNAs; Molecular Structure; Quercetin; Tumor Suppressor Protein p53

Isorhamnetin is a 3'-O-methylated metabolite of quercetin that is found predominantly in a variety of medicinal plants. Although many previous studies have reported that this flavonol has diverse health-promoting effects, evidence for the underlying molecular mechanism of anti-cancer efficacy is still lacking. In this study, it was examined the anti-proliferative effect of isorhamnetin on human hepatocarcinoma Hep3B cells, and found that isorhamnetin induced cell cycle arrest at G2/M phase and apoptosis. Isorhamnetin-induced G2/M arrest was associated with decreased expression of proliferating cell nuclear antigen as well as cyclin A and cyclin B1. However, isorhamnetin increased expression of p21WAF1/CIP1, a cyclin-dependent kinase (Cdk) inhibitor, and increased p21 complexed with Cdk2 and Cdc2. In addition, Isorhamnetin-induced apoptosis was associated with increased expression of Fas/Fas ligand, reduced ratio of Bcl-2/Bax expression, truncation of Bid, cytosolic release of cytochrome c, and activation of caspase-8, -9 and -3. Isorhamnetin also enhanced intracellular levels of reactive oxygen species (ROS), while the addition of N-acetyl cysteine (NAC), a ROS inhibitor, significantly diminished isorhamnetin-induced mitochondrial dysfunction. Furthermore, the interruption of ROS generation using NAC significantly attenuated isorhamnetin-mediated G2/M arrest and apoptosis. Collectively, this is the first report to show that isorhamnetin inhibited the proliferation of human hepatocarcinoma cells by ROS-dependent arrest of the cell cycle at the G2/M phase and induction of apoptosis.

Topics: Apoptosis; Cell Division; Cell Line, Tumor; G2 Phase Cell Cycle Checkpoints; Humans; Liver Neoplasms; Quercetin; Reactive Oxygen Species

Isorhamnetin, a flavonol aglycone, isolated from the traditional Chinese medicine Hippophae rhamnoides L., was investigated in its cytotoxicity and its influence on human hepatocellular carcinoma cells (BEL-7402). The cytotoxic effects of isorhamnetin showed dose- and time-dependency against BEL-7402 cells, with IC(50) equal to 74.4+/-1.13 microg ml(-1) after treatment with isorhamnetin for 72 h. Cytotoxicity of the flavonols on tumor cells depends on cellular accumulation of the drugs. The amount of isorhamnetin accumulated in BEL-7402 cells was assayed by high-performance liquid chromatography (HPLC) and showed that isorhamnetin could permeate the cell membrane into the cell. Staining with Hoechst 33258 showed fragmentation and condensation of chromatin in the cell treated with 50 microg ml(-1) isorhamnetin for 48 h. Flow cytometric analysis was performed to determine hypodiploid cells. The results of flow cytometry assay indicated that the percentage of hypodiploid BEL-7402 cells were 13.77+/-1.05% after 48 h treatment with 50 microg ml(-1) isorhamnetin. The treatment resulted in the appearance of a hypodiploid peak (sub-G(0)/G(1) peak), probably due to the presence of cells in apoptosis and apoptotic bodies with DNA content less than 2n. To our knowledge, this is the first report against human hepatocellular carcinoma cells (BEL-7402) of isorhamnetin.

Topics: Antineoplastic Agents, Phytogenic; Apoptosis; Carcinoma, Hepatocellular; Cell Line, Tumor; Cell Nucleus; Chromatography, High Pressure Liquid; Flavonols; G1 Phase; Hippophae; Humans; Liver Neoplasms; Quercetin