The study on DNA methylation of p53-Bax mitochondrial apoptosis pathway in cholangiocarcinoma

Objective： To study the methylation status of several genes on p53-Bax mitochondrial apoptosis pathway and clinical significance in cholangiocarcinoma. Methods： Promoter hypermethylation of DAPK, p14 and ASC genes were detected by methylation-specific PCR. p53 gene status （exon 5-8） were examined by automated sequencing, combined with the clinical documents of patients by statistics analysis. Results： （1） We found 66.7% of 36 cases cholangiocarcinoma had methylation of at least one tumor suppressor gene. The frequency of tumor suppressor gene methylation in cholangiocarcinoma was： p14 （24%）, DAPK （30.6%）, TMSI/ASC （36.1%）. The frequency of tumor suppressor gene methylation in tissues near cancer was： DAPK （5.6%）, TMS1/ASC （8.3%）. （2） p53 gene mutations were found in 22 of 36 patients （61.1%）. （3） There were no statistically relationship among the methylation of DAPK, p14 and ASC genes. There were negative relationship differences between the methylation of p14 and p53 gene mutation （P 〈 0.05）. （4） p53 gene mutation combined with the methylation of tumor suppressor were 14 cases （38.9%）. There were statistically differences on extent of pathologic biology, differentiation and invasion （P 〈 0.05）. Conclusion： Our study indicated that methylation of p53-Bax mitochondrial apoptosis pathway in cholangiocarcinoma was a common epigenetic event. Although the methylation of ASC, DAPK genes was low, it might be significance for early diagnosis, p53 gene mutation combined with the methylation of tumor suppressor might be relationship with pathologic biology, it trended to more malignancy.

Pien Tze Huang Inhibits Proliferation of Colorectal Cancer Cells through Suppressing PNO1 Expression and Activating p53/p21 Signaling Pathway

ObjectiveTo explore the regulatory effect of Pien Tze Huang (PZH) on targeting partner of NOB1 (PNO1) and it’s down-stream mediators in colorectal cancer (CRC) cells.MethodsQuantitative polymerase chain reaction was performed to determine mRNA levels of PNO1, TP53, and CDKN1A. Western blotting was performed to determine protein levels of PNO1, p53, and p21. HCT-8 cells were transduced with a lentivirus over-expressing PNO1. Colony formation assay was used to detect cell survival in PNO1 overexpression of HCT-8 cells after PZH treatment. Cell-cycle distribution, cell viability and cell apoptosis were performed to identify the effect of PNO1 overexpression on cell proliferation and apoptosis of HCT-8 cells after PZH treatment. Xenograft BALB/c nude mice bearing HCT116 cells transduced with sh-PNO1 or sh-Ctrl lentivirus were evaluated. Western blot assay was performed to detect PNO1, p53, p21 and PCNA expression in tumor sections. Terminal deoxynucleotidyl transferase dUTP nick end labling (TUNEL) assay was used to determine the apoptotic cells in tissues.ResultsPZH treatment decreased cell viability, down-regulated PNO1 expression, and up-regulated p53 and p21 expressions in HCT-8 cells (P<0.05). PNO1 overexpression attenuated the effects of PZH treatment, including the expression of p53 and p21, cell growth, cell viability, cell cycle arrest and cell apoptosis in vitro (P<0.05). PNO1 knockdown eliminated the effects of PZH treatment on tumor growth, inhibiting cell proliferation inhibition and apoptosis induction in vivo (P<0.05). Similarly, PNO1 knockdown attenuated the effects of PZH treatment on the down-regulation of PNO1 and up-regulation of p53 and p21 in vivo (P<0.05).ConclusionThe mechanism by which PZH induces its CRC anti-proliferative effect is at least in part by regulating the expression of PNO1 and its downstream targets p53 and p21.

Network pharmacology analysis combined with experimental verification of the molecular mechanism of Xihuang pill in treating liver cancer

Background:Xihuang pill is a kind of traditional Chinese medicine,which has been widely used in the treatment of kinds of cancer.However,there is still a lack of systematic understanding of the molecular mechanism of Xihuang pill in the treatment of liver cancer.In this work,we aim to explore the molecular mechanism of Xihuang pill in treating liver cancer.Methods:The functional components in Xihuang pill were collected from Traditional Chinese Medicine Database and Analysis Platform.The target genes of these components were also collected using Traditional Chinese Medicine Database and Analysis Platform.The target genes of liver cancer were predicted using GeneCards database.The intersecting genes were then analyzed with Venn diagrams.Kyoto Encyclopedia of Genes and Genomes and Database for Annotation,Visualization,and Integrated Discovery were used to analyze the pathway.Then,cell counting kit-8 was used to measure the half-maximal inhibitory concentration of Xihuang pills.The living dead cell staining method was used to observe the survival of cells.HepG2 cell apoptosis was tested by flow cytometry with fluorescein isothiocyanate/propidium iodide double staining method,and then the mitochondrial damage was also detected by flow cytometry.The expression of target genes was detected by quantitative real-time polymerase chain reaction.Results:A total of 130 compounds and 198 genes were identified as potential active ingredients and putative liver cancer‑related targets.We obtained 1,899 disease targets and 297 transcriptome targets from the database.Six drug-disease intersecting genes,CCNB1,BIRC5,TOP2A,ESR1,IGF2 and IGFBP3 were obtained.They are enrichment in apoptosis,PI3K-AKT signaling pathway,MAPK signaling pathway,pathways in cancer and p53 signaling pathway.Besides,it was found that the apoptosis rate of the HepG2 cells in Xihuang pill treated group was significantly higher than that of the control group.And the apoptosis rate gradually increased in a dose dependent manner of Xihuang pill treatment.Xihuang pill also induced the mitochondrial membrane potential damage.Compared with the control group,the expression level of CCNB1 and BIRC5 was induced,while the expression level of IGF2 was reduced after Xihuang pill treatment.Conclusion:Xihuang pill may act on six proteins(CCNB1,BIRC5,TOP2A,ESR1,IGF2 and IGFBP3)and cover multiple pathways to form a therapeutic network to treat liver cancer.

Real-time in situ observation of P53-mediated cascade activation of apoptotic pathways with nucleic acid multicolor fluorescent probes based on symmetrical gold nanostars

T-2 toxin,one of the most dangerous natural pollutants,induces apoptosis through multiple pathways.Amongst,P53 mediated apoptosis pathway,an important collection of molecules,plays a key role in cell vital activity.Real-time monitoring of upstream and downstream activation relationships of P53 mRNA,Bax mRNA,and cytochrome c(Cyt c)in signaling pathways is of great significance for understanding the apoptotic machinery in human physiology.In this work,a novel nucleic acid multicolor fluorescent probe,based on silica-coated symmetric gold nanostars(S-AuNSs@SiO_(2)),was developed for highly sensitive in situ real-time imaging of P53 mRNA,Bax mRNA,and Cyt c during T-2 toxin-induced apoptosis.The nucleic acid chains modified with carboxyl groups were modified on the surface of S-AuNSs@SiO_(2)by amide reaction.The complementary chains of targeted mRNA and the aptamer of targeted Cyt c were modified with different fluorophores,respectively,and successfully hybridized on S-AuNSs@SiO_(2)surface.When targets were present,the fluorescent chains bound to the targets and detached from the material,resulting in the quenched fluorescence being revived.The probes based on S-AuNSs showed excellent performance is partly ascribed to the presence of 20 symmetric“hot spots”.Notably,the amide-bonded probe exhibited excellent anti-interference capability against biological agents(nucleases and biothiols).During the real-time fluorescence imaging of T-2 toxin-induced apoptosis,the corresponding fluorescence signals of P53 mRNA,Bax mRNA,and Cyt c were observed sequentially.Therefore,S-AuNSs@SiO_(2)probe not only provides a novel tool for real-time monitoring of apoptosis pathways cascade but also has considerable potential in disease diagnosis and pharmaceutical medical.

Huanglian decoction suppresses the growth of hepatocellular carcinoma cells by reducing CCNB1 expression

BACKGROUND Hepatocellular carcinoma(HCC)is one of the most prevalent cancers in human populations worldwide.Huanglian decoction is one of the most important Chinese medicine formulas,with the potential to treat cancer.AIM To investigate the role and mechanism of Huanglian decoction on HCC cells.METHODS To identify differentially expressed genes(DEGs),we downloaded gene expression profile data from The Cancer Genome Atlas Liver Hepatocellular Carcinoma and Gene Expression Omnibus(GSE45436)databases.We obtained phytochemicals of the four herbs of Huanglian decoction from the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform.We also established a regulatory network of DEGs and drug target genes and subsequently analyzed key genes using bioinformatics approaches.Furthermore,we conducted in vitro experiments to explore the effect of Huanglian decoction and to verify the predictions.In particular,the CCNB1 gene was knocked down to verify the primary target of this decoction.Through the identification of the expression levels of key proteins,we determined the primary mechanism of Huanglian decoction in HCC.RESULTS Based on the results of the network pharmacological analysis,we revealed 5 bioactive compounds in Huanglian decoction that act on HCC.In addition,a protein-protein interaction network analysis of the target genes of these five compounds as well as expression and prognosis analyses were performed in tumors.CCNB1 was confirmed to be the primary gene that may be highly expressed in tumors and was significantly associated with a worse prognosis.We also noted that CCNB1 may serve as an independent prognostic indicator in HCC.Moreover,in vitro experiments demonstrated that Huanglian decoction significantly inhibited the growth,migration,and invasiveness of HCC cells and induced cell apoptosis and G2/M phase arrest.Further analysis showed that the decoction may inhibit the growth of HCC cells by downregulating the CCNB1 expression level.After Huanglian decoction treatment,the expression levels of Bax,caspase 3,caspase 9,p21 and p53 in HCC cells were increased,while the expression of CDK1 and CCNB1 was significantly decreased.The p53 signaling pathway was also found to play an important role in this process.CONCLUSION Huanglian decoction has a significant inhibitory effect on HCC cells.CCNB1 is a potential therapeutic target in HCC.Further analysis showed that Huanglian decoction can inhibit HCC cell growth by downregulating the expression of CCNB1 to activate the p53 signaling pathway.

Extract from Zanthoxylum piperitum Induces Apoptosis of AGS Gastric Cancer Cells through Akt/MDM2/p53 Signaling Pathway

Objective:To determine the effect of Zanthoxylum piperitum extracet(ZPE)on apoptosis and analyze anticancer substances in ZPE,changes in proteins related to apoptosis,and pathological changes in tumors in mouse.Methods:Fifteen 4-week-old female BALB/c nu/nu mice were divided into 3 groups depending on ZPE dose,with 5 in each group.AGS gastric carcinoma cells(1 x 10^(6) cells/200 jxL)were subcutaneously injected into the flank of each mouse.One week after the injection of AGS cells,ZPE was administered to the skin tissue[10 or 50 mg/(kg-d)]in the low-and high-dose groups,respectively for 20 days.Control animals were injected with vehicle only.After 3 weeks,the tumor was extracted and carried out for immunohistochemistry,the tendency of apoptosis and p53 in the body was checked using TdT-mediated dUTP nick-end labeling(TUNEL)assay.For 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT)assay,annexin V dead cell staining,cell cycle arrest and Western blotting,AGS gastric carcinoma cells were incubated with various concentrations of ZPE for 24 h.Cell survival rates were analyzed by MTT assays.Apoptosis was analyzed using annexin V dead cell staining and cell cycle arrest and measured using Muse cell analyzer.Results:High performance liquid chromatography(HPLC)analysis showed that ZPE contained organic sulfur compounds such as alliin and S-allylcysteine.MTT assay results revealed that ZPE(10-85»xg/mL)could effectively inhibit the growth of AGS gastric cancer cells at higher concentrations(P<0.05,P<0.01).The annexin V&dead cell staining assay and cell cycle arrest assay confirmed a dose-dependent increase in the apoptosis rate and G!phase in ZPE(10-70 jig/mL)groups.ZPE decreased the expression of anti-apoptotic proteins(p-Akt,p-MDM2,Bcl-2),while increased pro-apoptotic proteins(cleaved PARP,p53,pro-Caspase 3,Bax).TUNEL assays revealed an increase in cell apoptosis.Immunohistochemistry staining confirmed the involvement of p53.Conclusion:ZPE decreases AGS cell proliferation and induces apoptosis by inhibiting Akt and MDM2 expression.

A comprehensive view on the fisetin impact on colorectal cancer in animal models: Focusing on cellular and molecular mechanisms

Flavonoids, including fisetin, have been linked to a reduced risk of colorectal cancer(CRC) and have potential therapeutic applications for the condition. Fisetin, a natural flavonoid found in various fruits and vegetables, has shown promise in managing CRC due to its diverse biological activities. It has been found to influence key cell signaling pathways related to inflammation, angiogenesis, apoptosis, and transcription factors.The results of this study demonstrate that fisetin induces colon cancer cell apoptosis through multiple mechanisms. It impacts the p53 pathway, leading to increased levels of p53 and decreased levels of murine double minute 2, contributing to apoptosis induction. Fisetin also triggers the release of important components in the apoptotic process, such as second mitochondria-derived activator of caspase/direct inhibitor of apoptosis-binding protein with low pI and cytochrome c. Furthermore, fisetin inhibits the cyclooxygenase-2 and wingless-related integration site(Wnt)/epidermal growth factor receptor/nuclear factor kappa B signaling pathways, reducing Wnt target gene expression and hindering colony formation. It achieves this by regulating the activities of cyclin-dependent kinase 2 and cyclin-dependent kinase 4, reducing retinoblastoma protein phosphorylation, decreasing cyclin E levels, and increasing p21 levels, ultimately influencing E2 promoter binding factor 1 and cell division cycle 2(CDC2) protein levels. Additionally, fisetin exhibits various effects on CRC cells, including inhibiting the phosphorylation of Y-box binding protein 1 and ribosomal S6 kinase, promoting the phosphorylation of extracellular signal-regulated kinase 1/2, and disrupting the repair process of DNA double-strand breaks. Moreover, fisetin serves as an adjunct therapy for the prevention and treatment of phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit α(PIK3CA)-mutant CRC, resulting in a reduction in phosphatidylinositol-3 kinase(PI3K) expression, Ak strain transforming phosphorylation,m TOR activity, and downstream target proteins in CRC cells with a PIK3CA mutation.These findings highlight the multifaceted potential of fisetin in managing CRC and position it as a promising candidate for future therapy development.

Oscillatory behavior of p53-Mdm2 system driven by transcriptional and translational time delays

Biological experiments clarify that p53-Mdm2 module is the core of tumor network and p53 oscillation plays an important role in determining the tumor cell fate.In this paper,we investigate the effect of time delay on the oscillatory behavior induced by Hopf bifurcation in p53-Mdm2 system.First,the stability of the unique positive equilibriurm point and the existence of Hopf bifurcation are investigated by using the time delay as the bifurcation parameter and by applying the bifurcation theory.Second,the explicit criteria determining the direction of Hopf bifurcation and the stability of bifurcating periodic solutions are developed based on the normal form theory and the center manifold theorem.In addition,the combination of numerical simulation results and theoretical calculation results indicates that time delays in p53-Mdm2 system are critical for p53 oscillations.The results may help us to better understand the biological functions of p53 pathway and provide clues for treatment of cancer.