Wogonin is a plant flavonoid compound extracted from Scutellaria baicalensis (Huang-Qin or Chinese skullcap) and has been studied thoroughly by many researchers till date for its anti-viral, anti-oxidant, anti-cancerous and neuro-protective properties. Numerous experiments conducted in vitro and in vivo have demonstrated wogonin's excellent tumor inhibitory properties. The anti-cancer mechanism of wogonin has been ascribed to modulation of various cell signaling pathways, including serine-threonine kinase Akt (also known as protein kinase B) and AMP-activated protein kinase (AMPK) pathways, p53-dependent/independent apoptosis, and inhibition of telomerase activity. Furthermore, wogonin also decreases DNA adduct formation with a carcinogenic compound 2-Aminofluorene and inhibits growth of drug resistant malignant cells and their migration and metastasis, without any side effects. Recently, newly synthesized wogonin derivatives have been developed with impressive anti-tumor activity. This review is the succinct appraisal of the pertinent articles on the mechanisms of anti-tumor properties of wogonin. We also summarize the potential of wogonin and its derivatives used alone or as an adjunct therapy for cancer treatment. Furthermore, pharmacokinetics and side effects of wogonin and its analogues have also been discussed.
Animals ; Antineoplastic Agents, Phytogenic ; pharmacology ; therapeutic use ; DNA Adducts ; metabolism ; Drug Resistance, Neoplasm ; drug effects ; Drugs, Chinese Herbal ; pharmacology ; therapeutic use ; Flavanones ; pharmacology ; therapeutic use ; Humans ; Neoplasms ; drug therapy ; metabolism ; Phytotherapy ; Scutellaria baicalensis ; chemistry ; Signal Transduction ; drug effects

The occurrence and development of acute myeloid leukemia (AML) is not only related to gene mutations, but also influenced by abnormal epigenetic regulation, in which DNA methylation is one of the most important mechanisms. Abnormal DNA methylation may lead to the activation of oncogene and the inactivation of tumor suppressor gene, resulting in the occurrence of leukemia. The mutations of DNA methylation enzymes associated with AML may have certain characteristics. The AML with recurrent cytogenetic abnormalities is also related to abnormal methylation. Some fusion genes can alter DNA methylation status to participate in the pathogenesis of leukemia. In addition, chemotherapy drug resistance in patients with AML is associated with the change of gene methylation status. Considering the reversibility of the epigenetic modification, targeted methylation therapy has become a hotspot of AML research.
DNA Methylation ; drug effects ; genetics ; physiology ; DNA Modification Methylases ; genetics ; physiology ; Drug Resistance, Neoplasm ; genetics ; Epigenesis, Genetic ; genetics ; physiology ; Humans ; Leukemia, Myeloid, Acute ; etiology ; genetics ; pathology ; Mutation ; genetics

To investigate the effect of RAD18-siRNA on cell proliferation and chemotherapy sensitivity of esophageal squamous cell carcinoma (ESCC) ECA-109 cells.RAD18-siRNA was transfected into human ECA-109 cells by Lipofectamine 3000. Quantitative PCR and Western blot were performed to detect RAD18 and CyclinD1 expression; CCK-8 assay was used to determine cell proliferation and chemotherapy drug sensitivity; flow cytometry was used to determine cell cycle. Correlation between RAD18 and CyclinD1 mRNA expression was analyzed by Pearson's correlation.Compared with non-transfected cells, the expression of RAD18 in RAD18-siRNA group was significantly decreased (<0.05). The cell proliferation was inhibited (<0.05) and the cell number of G1 phase was increased, G2/M phase cells decreased (<0.05) in RAD18-siRNA group. After treatment with different concentrations of cisplatin or 5-FU, the survival rate of the two cell groups was reduced (all<0.05), and the IC50 of RAD18-siRNA group was significantly lower than that of non-transfected group (<0.05). The mRNA expression of RAD18 was positively correlated with CyclinD1 expression in ESCC tissues(=0.478,<0.01).Down-regulated expression of RAD18 can decrease the cell proliferation and increase chemo-sensitivity of ESCC cells, and CyclinD1 may participate in the process.
Adjuvants, Pharmaceutic ; pharmacology ; Carcinoma, Squamous Cell ; drug therapy ; physiopathology ; Cell Cycle ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Cisplatin ; pharmacology ; Cyclin D1 ; drug effects ; genetics ; DNA-Binding Proteins ; administration & dosage ; pharmacology ; Down-Regulation ; drug effects ; genetics ; Drug Resistance, Neoplasm ; drug effects ; Drug Screening Assays, Antitumor ; methods ; Drug Synergism ; Esophageal Neoplasms ; drug therapy ; physiopathology ; Fluorouracil ; pharmacology ; G1 Phase ; drug effects ; G2 Phase ; drug effects ; Humans ; Metaphase ; drug effects ; RNA, Small Interfering ; administration & dosage ; pharmacology ; Transfection ; Ubiquitin-Protein Ligases ; administration & dosage ; pharmacology

Although methyltransferase has been recognized as a major element that governs the epigenetic regulation of the genome during temozolomide (TMZ) chemotherapy in glioblastoma multiforme (GBM) patients, its regulatory effect on glioblastoma chemoresistance has not been well defined. This study investigated whether DNA methyltransferase (DNMT) expression was associated with TMZ sensitivity in glioma cells and elucidated the underlying mechanism. DNMT expression was analyzed by western blotting. miR-20a promoter methylation was evaluated by methylation-specific PCR. Cell viability and apoptosis were assessed using the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) and TdT-mediated dUTP-biotin nick end labeling assays, respectively. The results showed that compared with parental U251 cells, DNMT1 expression was downregulated, miR-20a promoter methylation was attenuated and miR-20a levels were elevated in TMZ-resistant U251 cells. Methyltransferase inhibition by 5-aza-2\'-deoxycytidine treatment reduced TMZ sensitivity in U251 cells. In U251/TM cells, DNMT1 expression was negatively correlated with miR-20a expression and positively correlated with TMZ sensitivity and leucine-rich repeats and immunoglobulin-like domains 1 expression; these effects were reversed by changes in miR-20a expression. DNMT1 overexpression induced an increase in U251/TM cell apoptosis that was inhibited by the miR-20a mimic, whereas DNMT1 silencing attenuated U251/TM cell apoptosis in a manner that was abrogated by miR-20a inhibitor treatment. Tumor growth of the U251/TM xenograft was inhibited by pcDNA-DNMT1 pretreatment and boosted by DNMT1-small hairpin RNA pretreatment. In summary, DNMT1 mediated chemosensitivity by reducing methylation of the microRNA-20a promoter in glioma cells.
Animals ; Antineoplastic Agents, Alkylating/*pharmacology/therapeutic use ; Apoptosis/drug effects ; Brain/drug effects/metabolism/pathology ; Brain Neoplasms/drug therapy/*genetics/pathology ; DNA (Cytosine-5-)-Methyltransferase/antagonists & inhibitors/*genetics/metabolism ; DNA Methylation ; Dacarbazine/*analogs & derivatives/pharmacology/therapeutic use ; Drug Resistance, Neoplasm ; Female ; Gene Expression Regulation, Neoplastic ; Glioma/drug therapy/*genetics/pathology ; Humans ; Mice, Inbred C57BL ; MicroRNAs/*genetics ; Promoter Regions, Genetic

OBJECTIVETo investigate the promoter methylation of p16, FHIT and RASSF1A gene and telomere damage in the workers exposed to coal tar pitch, and to explore the effective biomarker of occupational exposure to coal tar pitch.

METHODS180 cases of workers exposed to coal tar pitch in a certain carbon plant named as exposure group, and 145 healthy cases with a medical examination in the first affiliated hospital of Zhengzhou University were selected as control group. Relative telomere length in peripheral blood DNA was detected using real-time quantitative PCR, and the promoter methylation rate of p16, RASSF1A and FHIT gene in peripheral blood DNA were determined by real-time quantitative methylation specific PCR. The relative telomere length and gene promoter methylation in two groups were compared, and influencing factors were analyzed.

RESULTSRelative telomere length in exposed group was lower than that in the control group, and the difference was statistically significant (Z = -5.395, P < 0.001). There was no significant difference in the promoter methylation rate of p16, FHIT and RASSF1A gene between the two groups (P > 0.05). Stratification analysis by gender, age, and smoking, we found that when the age was less than or equal to 40, the promoter methylation rate of p16 in exposed group was more than that in control group, and the difference was statistically significant (Z = -1.914, P = 0.011).

CONCLUSIONOccupational exposure to coal tar pitch may induce leukocyte DNA telomere length of human peripheral blood shortened, and may not change the promoter methylation rates of p16, FHIT and RASSF1A gene.

Acid Anhydride Hydrolases ; genetics ; Coal Tar ; adverse effects ; Cyclin-Dependent Kinase Inhibitor p16 ; genetics ; DNA Methylation ; Humans ; Leukocytes ; drug effects ; Neoplasm Proteins ; genetics ; Occupational Exposure ; adverse effects ; Promoter Regions, Genetic ; Telomere ; drug effects ; ultrastructure ; Tumor Suppressor Proteins ; genetics

OBJECTIVETo explore the effect of peimine on excision repair cross-complementation 1 (ERCC1) mRNA and lung resistant protein (LRP) expressions in A549/cisplatin (DDP) multidrug resistance (MDR) cell line.

METHODSLung cancer A549/DDP cells were cultured in vitro.Cells at logarithmic growth phase were divided into 4 groups, i.e., the blank control group, the DDP group, the ligustrazine group (DDP+ligustrazine), the peimine group (DDP + peimine). After 48-h drug action, ERCC1 mRNA expression was detected by RT-PCR and LRP expression detected by cell immunofluorescence.

RESULTSThere was no statistical difference in expression levels of ERCC1 mRNA and LRP between the DDP group and the blank control group (P > 0.05). Compared with the DDP group, expression levels of ERCC1 mRNA and LRP obviously decreased in the ligustrazine group and the peimine group (P < 0.05). They were obviously lower in the peimine group than in the ligustrazine group (P < 0.05).

CONCLUSIONSPeimine could reverse MDR of A549/DDP cell line. Its mechanism might be associated with down-regulating ERCC1 mRNA and LRP expression levels.

Cell Line, Tumor ; Cevanes ; pharmacology ; Cisplatin ; DNA-Binding Proteins ; genetics ; Down-Regulation ; Drug Resistance, Multiple ; Drug Resistance, Neoplasm ; drug effects ; Endonucleases ; genetics ; Humans ; Low Density Lipoprotein Receptor-Related Protein-1 ; genetics ; Lung Neoplasms ; RNA, Messenger ; metabolism

OBJECTIVEOleanolic acid (OA) has been reported to have anticancer effects, but the extent of its cytotoxicity, its ability to interact with nuclear DNA, its action against skin melanoma, as well as the molecular mechanism of its action against cell proliferation and in support of cell death are still unexplored. This led us to examine the efficacy of OA, a bioactive compound isolated from Phytolacca decandra, on these issues in the present investigation.

METHODSStudies related to analyses of cell viability, drug-DNA interaction, cell proliferation, cell cycle and epidermal growth factor receptor (EGFR) activity were performed. To investigate whether cells undergo apoptosis, studies like fluorescence microscopy, poly (ADP-ribose) polymerase (PARP) degradation, annexin V-fluorescein isothiocyanate/propidium iodide assay, alteration in mitochondrial membrane potential and activity of some relevant signaling proteins were performed.

RESULTSOA displayed a minimal and negligible cytotoxic effect on normal HaCaT cells (skin keratinocytes) and peripheral blood mononuclear cells but by contrast it reduced A375 cell viability significantly. OA interacted with nuclear DNA quickly after exposure. It acted as an anti-proliferative agent. It suppressed EGFR activity. OA administration led the cells to mitochondria-dependent caspase 3-mediated apoptosis.

CONCLUSIONOA interacts with cellular DNA, inhibits proliferation possibly through modulating EGFR activity and induces mitochondria-dependent caspase 3-mediated apoptosis in A375 cells which would qualify it as a potent anticancer agent.

Antineoplastic Agents ; isolation & purification ; therapeutic use ; Apoptosis ; drug effects ; Cell Line, Tumor ; DNA, Neoplasm ; drug effects ; Humans ; Melanoma ; drug therapy ; Microscopy, Fluorescence ; Oleanolic Acid ; isolation & purification ; therapeutic use ; Phytolacca ; chemistry ; Phytotherapy ; methods ; Plant Extracts ; isolation & purification ; therapeutic use ; Receptor, Epidermal Growth Factor ; drug effects ; physiology ; Signal Transduction ; drug effects ; Skin Neoplasms ; drug therapy

PURPOSE: Both genetic and epigenetic alterations can lead to abnormal expression of metastasis-regulating genes in tumor cells. Recent studies suggest that aberrant epigenetic alterations, followed by differential gene expression, leads to an aggressive cancer cell phenotype. We examined epigenetically regulated genes that are involved in ovarian cancer metastasis. MATERIALS AND METHODS: We developed SK-OV-3 human ovarian carcinoma cell xenografts in mice. We compared the mRNA expression and DNA methylation profiles of metastatic tissues to those of the original SK-OV-3 cell line. RESULTS: Metastatic implants showed increased mRNA expression of the carbonic anhydrase 9 (CA9) gene and hypomethylation at CpG sites in the CA9 promoter. Treatment of wild-type SK-OV-3 cells with the DNA methyltransferase inhibitor 5-aza-2'-deoxycytidine reduced methylation of the CA9 promoter and increased CA9 mRNA expression. Eight CpGs, which were located at positions -197, -74, -19, -6, +4, +13, +40, and +86, relative to the transcription start site, were hypomethylated in metastatic tumor implants, compared to that of wild-type SK-OV-3. Overexpression of CA9 induced an aggressive phenotype, including increased invasiveness and migration, in SK-OV-3 cells. CONCLUSION: Alterations in the DNA methylation profile of the CA9 promoter were correlated with a more aggressive phenotype in ovarian cancer cells.
Animals ; Azacitidine/*analogs & derivatives/pharmacology ; Carbonic Anhydrases/metabolism ; *DNA Methylation ; Female ; Gene Expression Regulation, Neoplastic/*drug effects ; Humans ; Mice ; Neoplasm Invasiveness/genetics ; Neoplasm Metastasis/genetics/*pathology ; Neoplasms, Experimental ; Neoplasms, Glandular and Epithelial/genetics/*metabolism/pathology ; Ovarian Neoplasms/genetics/*metabolism/pathology ; Phenotype ; Promoter Regions, Genetic ; RNA, Messenger/metabolism

OBJECTIVE: To investigate the effect of arsenic trioxide (As2O3) combined with cisplatin on expression of RASSF1A in nude mice with human nasopharyngeal carcinoma xenograft. METHOD: The models of human poorly differentiated nasopharyngeal carcinoma in nude mice were established and randomly divided into four groups, control group (NaCl group), As2O3 group, DDP group and As2O3 + DDP group. The expression of RASSF1A mRNA and protein were detected by Real-time RT-PCR and immunohistochemistry respectively. The methylation rate of RASSF1A promoter CpG islands was analyzed by HRM. RESULTS: Experimental groups could obviously inhibit the growth of tumor and up-regulate the expression of RASSF1A. The methylation rate of RASSF1A in transplanted tumors in experimental groups was lower than the control group. Especially As2O3 combined with DDP were superior to the single drug use. CONCLUSION As2O3 inhibits the growth of human nasopharyngeal carcinoma cell strain CNE2 xenograft in nude mice and increases mRNA expression of RASSF1A. As2O3 inhibits the malignant phenotypes of human nasopharyngeal carcinoma cells and reverses hypermethylation of RASSF1A.
Animals ; Arsenic Trioxide ; Arsenicals ; pharmacology ; Carcinoma ; Cell Line, Tumor ; Cisplatin ; pharmacology ; DNA Methylation ; drug effects ; Humans ; Mice ; Mice, Nude ; Nasopharyngeal Carcinoma ; Nasopharyngeal Neoplasms ; genetics ; pathology ; Neoplasm Transplantation ; Oxides ; pharmacology ; Tumor Suppressor Proteins ; genetics ; Xenograft Model Antitumor Assays

A series of cycloberberine derivatives were designed, synthesized and evaluated for their anti-cancer activities in vitro. Among these analogs, compounds 6c, 6e and 6g showed strong inhibition on human HepG2 cells. They afforded a potent effect against DOX-resistant MCF-7 breast cells as well. The primary mechanism showed that cell cycle was blocked at G2/M phase of HepG2 cells treated with 6g using flow cytometry assay. It significantly inhibited the activity of DNA Top I at the concentration of 0.1 mg mL-1. Our results provided a basis for the development of this kind of compounds as novel anti-cancer agents.
Antineoplastic Agents ; chemical synthesis ; chemistry ; pharmacology ; Berberine ; analogs & derivatives ; chemical synthesis ; chemistry ; pharmacology ; Cell Cycle ; drug effects ; Cell Proliferation ; drug effects ; DNA Topoisomerases, Type I ; metabolism ; Doxorubicin ; pharmacology ; Drug Resistance, Neoplasm ; Hep G2 Cells ; Humans ; MCF-7 Cells ; Molecular Structure ; Structure-Activity Relationship