Pachymaran regulates pyroptosis of liver cancer cells via SQLE/NLRP3/GSDMD signaling pathway / 中国病理生理杂志

AIM:Using bioinformatics analysis and experiment validation to explore the differential expres-sion genes related to abnormal lipid metabolism in hepatocellular carcinoma(HCC)and the molecular mechanism of pachymaran affecting pyroptosis through squalene epoxidase(SQLE)/nucleotide-binding oligomerization domain-like re-ceptor protein 3(NLRP3)/gasdermin D(GSDMD)signaling pathway.METHODS:(1)The GEO,GSEA,DAVID,STRING and GEPIA databases were employed to screen abnormal lipid metabolism-related differentially expressed genes in HCC.(2)The tumor tissues from HCC patients(n=9)were collected to verify the differential expression of SQLE.(3)The inhibitory effect of pachymaran on the viability of human HCC cell line HepG2 was measured by CCK-8 assay.(4)The HepG2 cells were divided into control group and pachymaran(800 mg/L)group.The cell migration was analyzed by wound-healing assay,and RT-qPCR was used to measure SQLE mRNA expression.(5)The HepG2 cells with overexpres-sion of SQLE(OE-SQLE)were divided into 5 groups as follows:control group,overexpression negative control(OE-NC)group,OE-SQLE group,OE-NC+pachymaran group,and OE-SQLE+pachymaran group.The mRNA and protein expres-sion levels of SQLE and pyroptosis-related factors were determined by RT-qPCR and Western blot.Colorimetric method and ELISA were used to measure lactate dehydrogenase(LDH),interleukin-1β(IL-1β)and IL-18 levels.The necrosis of HepG2 cells was analyzed by flow cytometry.RESULTS:The SQLE gene was screened through bioinformatics analysis,and its mRNA expression was significantly increased in tumor tissues from HCC patients(P＜0.01).In cell experiments,treatment with 800 mg/L pachymaran for 48 h had a significant inhibitory effect on HepG2 cell viability,and the expres-sion of SQLE mRNA was reduced(P＜0.01).After overexpression of SQLE,the mRNA and protein levels of pyroptosis-re-lated factors,necrotic rate,and LDH,IL-1β and IL-18 levels were significantly decreased(P＜0.05).After treatment with pachymaran,the above indicators were significantly increased(P＜0.05).CONCLUSION:The SQLE is abnormal-ly highly expressed in HCC,and pachymaran can affect the growth of HCC cells by activating the NLRP3/GSDMD pyropto-sis pathway through SQLE.

The interaction between polyphyllin I and SQLE protein induces hepatotoxicity through SREBP-2/HMGCR/SQLE/LSS pathway / 药物分析学报

Polyphyllin Ⅰ(PPⅠ)and polyphyllin Ⅱ(PⅡ)are the main active substances in the Paris polyphylla.However,liver toxicity of these compounds has impeded their clinical application and the potential hepatotoxicity mechanisms remain to be elucidated.In this work,we found that PPⅠ and PⅡ exposure could induce significant hepatotoxicity in human liver cell line L-02 and zebrafish in a dose-dependent manner.The results of the proteomic analysis in L-02 cells and transcriptome in zebrafish indicated that the hepa-totoxicity of PPⅡ and PⅡwas associated with the cholesterol biosynthetic pathway disorders,which were alleviated by the cholesterol biosynthesis inhibitor lovastatin.Additionally,3-hydroxy-3-methy-lglutaryl CoA reductase(HMGCR)and squalene epoxidase(SQLE),the two rate-limiting enzymes in the choles-terol synthesis,selected as the potential targets,were confirmed by the molecular docking,the over-expression,and knockdown of HMGCR or SQLE with siRNA.Finally,the pull-down and surface plasmon resonance technology revealed that PPⅠ could directly bind with SQLE but not with HMGCR.Collectively,these data demonstrated that PPⅠ-induced hepatotoxicity resulted from the direct binding with SQLE protein and impaired the sterol-regulatory element binding protein 2/HMGCR/SQLE/lanosterol synthase pathways,thus disturbing the cholesterol biosynthesis pathway.The findings of this research can contribute to a better understanding of the key role of SQLE as a potential target in drug-induced hepatotoxicity and provide a therapeutic strategy for the prevention of drug toxic effects with similar structures in the future.

Effects of SQLE gene on proliferation, apoptosis, migration and invasion of squamous cervical cancer cells / 中国药理学通报

Aim To explore the effect of squalene ep-oxidase ( SQLE) in cervical squamous cell carcinoma and the molecular mechanism. Methods Firstly, the gene expression profiling interactive analysis (GEPIA) database was used to analyze the mRNA expression of SQLE in cervical squamous cell carcinoma and normal cervical tissues, and the human protein atlas ( HPA) database was used to obtain the expression of SQLE protein in cervical squamous cell carcinoma and normal cervical tissues. We researched the correlation between SQLE gene and the clinicopathological characteristics of cervical squamous cell carcinoma through UALCAN database. Then GEPIA database was utilized to evaluate the overall survival (OS) and disease free survival (DFS) of cervical squamous cell carcinoma patients with high expression of SQLE mRNA. Finally, Siha cells were taken as the research object, and the effects of SQLE gene on proliferation, apoptosis, migration and invasion of Siha cells were observed by using small interfering RNA ( siRNA) to inhibit the expression of SQLE gene and transfecting recombinant plasmid to promote the expression of SQLE gene. The mRNA expression of SQLE was assessed by qPT-PCR. Bax, Bcl-2, Vimentin, E-cadherin, PI3K, Akt, p-PI3K and p-Akt protein expression levels were examined by Western blot. Results The mRNA expression and protein expression of SQLE in cervical squamous cell carcinoma was higher than that in normal tissues (P < 0. 05 ), and the OS of patients with high expression of SQLE mRNA was significantly shortened in cervical squamous cell carcinoma ( P < 0. 05 ). The expression of SQLE in stage IV of cervical squamous cell carcinoma was significantly higher than that in stage I, II and III (P < 0. 01). And the expression of SQLE in lymph node metastasis Nl group was markedly higher than that in NO group ( P < 0. 01 ). Cell experiments showed that interference with SQLE could significantly inhibit the proliferation, migration and invasion of Siha cells, and promote their apoptosis (P < 0. 01 ). The trend was opposite when SQLE was overexpressed. SQLE knockdown decreased the protein expression levels of Bcl-2, Vimentin, p-PI3K and p-Akt, increased the protein expression levels of Bax and E-cadherin, and the ratio of Bcl-2/Bax decreased significantly (P < 0. 05, P < 0. 01 ) . The trend was opposite when SQLE was overexpressed. Conclusions SQLE is highly expressed in human cervical squamous cell carcinoma. SQLE may induce Siha cell proliferation, migration, invasion, and inhibit their apoptosis by regulating PDK/Akt signaling pathway.

Research Progress of Squalene Monooxygenase and Cancer / 肿瘤防治研究

Squalene monooxygenase (SQLE) is the rate-limiting enzyme of cholesterol biosynthesis. It plays a crucial role in regulating cholesterol homeostasis. Increasing evidence shows that SQLE is closely related to the occurrence, development, metastasis, and poor prognosis of various cancers. SQLE can not only promote the proliferation of cancer cells and epithelial-mesenchymal transformation but also play an important role in maintaining the stemness of cancer stem cells and regulating cholesterol homeostasis. SQLE may be a potential molecular target for cancer therapy. In this review, the role of SQLE in regulating cholesterol homeostasis in vivo; its function in the occurrence, development, and metastasis of various cancers; and its molecular mechanism were summarized. Screening new SQLE inhibitors may provide new ideas for targeted cancer therapy.