Hepatocellular carcinoma (HCC) is a major cause of cancer-related mortality in part due to its high resistance to chemotherapeutic drugs. The anti-apoptotic Mcl-1 expression has been reported as a resistance factor in various types of tumors. Here, we investigated the expression of Mcl-1 in hepatoma cells and HCC tissues and its relationship with p53, and analyzed the possibility of the gene as a molecular target for HCC therapy. HCC specimens of 30 patients were examined by immunohistochemistry for Mcl-1 and p53 expression. Mcl-1 expression in hepatoma cell lines was measured by RT-PCR and Western blotting. The suppression of Mcl-1 by RNA interference or specific phosphatidylinositol-3 kinase (PI3K) inhibitor, LY294002, was evaluated as monotherapy, and it was combined with mitomycin C (MMC) in treating hepatoma cell line HepG2. Cell viability and apoptosis were assessed by MTT and FACS analysis. Finally, changes of Mcl-1 or p53 expression in various hepatoma cell lines were examined after transfection with Mcl-1 siRNA, the Mcl-1 expression plasmid, or the wide-type p53 expression plasmid, respectively. Mcl-1 protein was remarkably enhanced in HCC tissues as compared with adjacent non-tumor liver tissues. In addition, Mcl-1 was prominently expressed in HepG2 and Hep3B cells, weakly in SMMC7721 cells, and not in L02 cells. P53 protein was also overexpressed in HCC tissues and there was a significant correlation between the expression of p53 and Mcl-1. Silencing Mcl-1 by RNAi or LY294002 downregulated Mcl-1 expression and led to decreased cell viability and increased apoptosis. Combination of MMC and Mcl-1 RNAi or LY294002 exhibited a significant chemosensitizing effect. The expression of p53 was not influenced by Mcl-1 siRNA in HepG2 cells or transfection with the Mcl-1 expression plasmid in L02 cells. Furthermore, the expression of Mcl-1 in Hep3B cells was also not significantly changed after transfection with the wild-type p53 expression plasmid. It is concluded that Mcl-1 is overexpressed in HCC tissues. The mechanisms by which silencing Mcl-1 sensitizes hepatoma cells towards chemotherapy may be not attributed to the upregulated expression of p53 but the dysfunction of p53 through Mcl-1/p53 interaction. Mcl-1 may be a potential target of gene therapy for HCC.
Adenoma, Liver Cell ; drug therapy ; genetics ; pathology ; Apoptosis ; drug effects ; Biomarkers, Tumor ; biosynthesis ; genetics ; Chromones ; administration & dosage ; Gene Expression Regulation, Neoplastic ; drug effects ; Hep G2 Cells ; Humans ; Liver Neoplasms ; drug therapy ; genetics ; pathology ; Morpholines ; administration & dosage ; Myeloid Cell Leukemia Sequence 1 Protein ; biosynthesis ; genetics ; RNA, Small Interfering ; genetics ; Transfection ; Tumor Suppressor Protein p53 ; biosynthesis ; genetics

OBJECTIVETo re-analyze the data published in order to explore plausible biological pathways that can be used to explain the anti-aging effect of curcumin.

METHODSMicroarray data generated from other study aiming to investigate effect of curcumin on extending lifespan of Drosophila melanogaster were further used for pathway prediction analysis. The differentially expressed genes were identified by using GeneSpring GX with a criterion of 3.0-fold change. Two Cytoscape plugins including BisoGenet and molecular complex detection (MCODE) were used to establish the protein-protein interaction (PPI) network based upon differential genes in order to detect highly connected regions. The function annotation clustering tool of Database for Annotation, Visualization and Integrated Discovery (DAVID) was used for pathway analysis.

RESULTSA total of 87 genes expressed differentially in D. melanogaster melanogaster treated with curcumin were identified, among which 50 were up-regulated significantly and 37 were remarkably down-regulated in D. melanogaster melanogaster treated with curcumin. Based upon these differential genes, PPI network was constructed with 1,082 nodes and 2,412 edges. Five highly connected regions in PPI networks were detected by MCODE algorithm, suggesting anti-aging effect of curcumin may be underlined through five different pathways including Notch signaling pathway, basal transcription factors, cell cycle regulation, ribosome, Wnt signaling pathway, and p53 pathway.

CONCLUSIONGenes and their associated pathways in D. melanogaster melanogaster treated with anti-aging agent curcumin were identified using PPI network and MCODE algorithm, suggesting that curcumin may be developed as an alternative therapeutic medicine for treating aging-associated diseases.

Aging ; drug effects ; genetics ; Animals ; Cell Cycle ; drug effects ; genetics ; Curcumin ; pharmacology ; Drosophila Proteins ; genetics ; metabolism ; Drosophila melanogaster ; drug effects ; genetics ; Gene Expression Regulation ; drug effects ; Gene Regulatory Networks ; drug effects ; Genes, Insect ; Protein Biosynthesis ; drug effects ; genetics ; Protein Interaction Maps ; drug effects ; genetics ; Receptors, Notch ; genetics ; metabolism ; Ribosomes ; drug effects ; metabolism ; Signal Transduction ; drug effects ; genetics ; Tumor Suppressor Protein p53 ; metabolism ; Wnt Signaling Pathway ; drug effects ; genetics

As an essential metal for sustaining life, iron is involved in a number of metabolic processes, including DNA synthesis, electron transport, oxygen delivery, and so on. Iron metabolism involves the absorption, transport, and use of iron and is strictly regulated. Numerous studies have found a positive correlation between iron storage and the risk of tumors, such as colorectal carcinoma, hepatic cancer, renal carcinoma, lung cancer, and gastric cancer. In tumor cells, iron metabolism changes by several mechanisms, such as regulating the growth of tumor cells by transferrin, accelerating the uptake of iron by the overexpressions of transferrin receptors 1 and 2 (TfR1 and TfR2), synthesizing or secreting ferritin by some malignant tumor cells, and upregulating the level of hepcidin in patients with cancer. Some advances on diagnosis and treatment based on iron metabolism have been achieved, such as increasing the transfection and target efficiency of transferrin-polyethylenimine (PEI), inducing cell apoptosis by beta-guttiferin through interacting with TfR1.
Animals ; Antibiotics, Antineoplastic ; pharmacology ; Antigens, CD ; genetics ; metabolism ; Antimicrobial Cationic Peptides ; biosynthesis ; genetics ; Apoptosis ; Cell Proliferation ; Doxorubicin ; pharmacology ; Ferritins ; metabolism ; physiology ; Hepcidins ; Humans ; Interleukin-18 ; pharmacology ; Iron ; metabolism ; physiology ; Neoplasms ; metabolism ; pathology ; RNA, Messenger ; metabolism ; Receptors, Transferrin ; genetics ; metabolism ; Transferrin ; metabolism ; physiology ; Tumor Suppressor Protein p53 ; pharmacology

Animals ; Cell Culture Techniques ; methods ; Cell Line ; Cell Proliferation ; Hepatocytes ; cytology ; metabolism ; Humans ; Liver ; cytology ; Liver Diseases ; therapy ; Liver, Artificial ; Mice ; Recombination, Genetic ; Simian virus 40 ; genetics ; Telomerase ; genetics ; metabolism ; Transfection ; Tumor Suppressor Protein p53 ; biosynthesis

To study the inhibitory effect of a recombinant adenoviral vector carrying human IL-24 gene on SGC-7901 human gastric cancer cell. We infected the SGC-7901 gastric cancer cells with Ad blank adenovirus at various multiplicity of infection (MOIs) to find the optimal infective dose. The SGC-7901 tumor cells were infected with Ad-IL-24 at the optimal MOI in the following experiments. Adenovirus-mediated IL-24 transcription expression in SGC-7901 cells was examined by RT-PCR. The growth-suppressing effect of Ad-IL-24 on SGC-7901 tumor cells was assessed by MTT assay. Apoptosis and cell cycle of SGC-7901 tumor cells infected with Ad-IL-24 was evaluated by flow cytometer (FCM), respectively. The karyomorphology of apoptotic SGC-7901 tumor cells was examined using Hoechst33258 staining under fluorescence microscopy. The expression of apoptosis-related genes was future determined by semi-quantification RT-PCR; We demonstrated that the MOI of 100 was the optimal infective dose in the study on adenovirus-mediated IL-24 gene transfer into SGC-7901 gastric cancer cell; IL-24 gene mediated by adenovirus could successfully transcribe in SGC-7901 tumor cells; Ad-IL-24 could significantly inhibit SGC-7901 tumor cell growth and induce apoptosis, it also can up-regulate the express of bax, caspase-3 and p53 whilst down-regulate the bcl-2 expression. Thus, adenovirus-mediated IL-24 expression had marked anti-tumor effect in suppressing SGC-7901 human gastric cancer cell growth and inducing apoptosis, which may be closely associated with its up-regulation of bax/bcl-2, caspase-3 and p53.
Adenoviridae ; genetics ; metabolism ; Apoptosis ; genetics ; Caspase 3 ; genetics ; metabolism ; Cell Line, Tumor ; Cell Proliferation ; Humans ; Interleukins ; biosynthesis ; genetics ; Proto-Oncogene Proteins c-bcl-2 ; genetics ; metabolism ; Recombinant Proteins ; biosynthesis ; genetics ; Stomach Neoplasms ; genetics ; pathology ; Transfection ; Tumor Suppressor Protein p53 ; genetics ; metabolism ; Up-Regulation ; bcl-2-Associated X Protein ; genetics ; metabolism

OBJECTIVE: To investigate the effect of human papillomavirus types 16E6 on the sensitivity of chemotherapy for cervical carcinoma in different p53 genotype cell lines. METHODS: The apoptosis rates of each group were detected by AO/EB, immunofluorescence and Annexin V/PI stained methods. The expressions of protein HPV16E6 and p53(mt) after the treatments of different concentration of DDP were detected by Western blot. HPV16E6 mRNA in C33A, C33A-E6, C33A-P, and CaSki cell lines under different DDP treatments were detected by RT-PCR. RESULTS: AO/EB and Annexin V/PI stained tests showed that the apoptosis rates of C33A, C33A-E6, C33A-P, and CaSki cells were significantly increased when DDP concentration increased. Western blot showed that the HPV16E6 protein could be detected only in C33A-E6 and CaSki cell lines. The expression of HPV16E6 protein in C33A-E6 and CaSki cell lines gradually decreased and was hardly detected with increased dosage of DDP and the prolonged treatment time (P<0.01), and slightly increased in C33A-E6 and Caski cell lines without the treatment, but there was no significant difference between them (P>0.05). Protein p53(mt) persistently expressed in C33A-E6, C33A, and C33A-P cell lines following the increased dosage of DDP and the prolonged treatment time(P>0.05), while it couldn't be found in CaSki cell line. RT-PCR showed that without DDP intervention, there was no significant difference of HPV16E6 mRNA in C33A-E6 and CaSki cell lines within 24 h.The HPV16E6 mRNA in C33A-E6 cell line expressed much higher than that in CaSki (P<0.05), and HPV16E6 mRNA of 2 cell lines expressed much higher at 48 h than at 24 h (P<0.05).The expression of HPV16E6 mRNA in C33A-E6 and CaSki cell lines gradually decreased with the increased DDP and prolonged treatment time (P<0.01), while there was no significant difference between C33A-E6 and CaSki cell lines under the same DDP concentration (P>0.05). CONCLUSION Effect of HPV16E6 on the sensitivity of chemotherapy for cervical carcinoma cell lines is not markedly related with the different p53 genotype forms(p53(mt)/p53wt ). HPV16E6 may affect the proliferation and sensitivity of chemotherapy in C33A cell line through other mechanism.
Antineoplastic Agents ; pharmacology ; Apoptosis ; genetics ; Cell Line, Tumor ; Cisplatin ; pharmacology ; Female ; Genotype ; Human papillomavirus 16 ; genetics ; Humans ; Oncogene Proteins, Viral ; biosynthesis ; genetics ; Papillomavirus Infections ; virology ; Repressor Proteins ; biosynthesis ; genetics ; Tumor Suppressor Protein p53 ; biosynthesis ; genetics ; Uterine Cervical Neoplasms ; pathology ; virology

OBJECTIVETo investigate effects of Sargassum confusum polysaccharide (SP) on the expressions of p53 and Rb genes.

METHODSThe mice bearing S180 sarcoma were treated with abdominal SP injection at the daily dose of 50, 100 or 200 mg/kg for 10 consecutive days, The mice injected with 0.85% saline served as the negative control group and those with 5-fluorouracil (5-FU) injection as the positive control group. The tumor weight was measured to calculate the tumor inhibition rate. RT-PCR and Western blotting were used to detect the expression levels of p53 and Rb genes at the mRNA and protein levels, respectively.

RESULTSThe 10-day SP treatment at 50, 100 and 200 mg/kg resulted in tumor growth inhibition rates of 30.5%, 47.6% and 63.5%, respectively. SP treatment upregulated the mRNA expressions and increased the protein levels of p53 and Rb in the tumors.

CONCLUSIONSP has inhibitory effect against S180 sarcoma in vivo and can increase the expression levels of p53 and Rb genes at both the mRNA and protein levels.

Animals ; Blotting, Western ; Cell Line, Tumor ; Female ; Gene Expression Regulation, Neoplastic ; drug effects ; Male ; Mice ; Polysaccharides ; isolation & purification ; pharmacology ; RNA, Messenger ; biosynthesis ; genetics ; Random Allocation ; Retinoblastoma Protein ; genetics ; metabolism ; Reverse Transcriptase Polymerase Chain Reaction ; Sarcoma 180 ; genetics ; metabolism ; pathology ; Sargassum ; chemistry ; Tumor Suppressor Protein p53 ; genetics ; metabolism

OBJECTIVETo evaluate the association between p53 codon 72 polymorphism (R72P) and the risk of colorectal liver metastases.

METHODSThe p53 R72P genotype was identified by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method in 78 consecutive colorectal cancer patients with liver metastases and 214 age- and sex-matched cases with nonmetastatic colorectal cancer.

RESULTSThe R allele of the p53 R72P polymorphism was more frequently found in metastatic cases than in nonmetastatic cases (P=0.075). Carriers of the 72R allele had a 2.25-fold (95% CI (confidence interval)=1.05 to approximately 4.83) increased risk of liver metastases. On the stratification analysis, 72R-carrying genotype conferred a 3.46-fold (95% CI=1.02 to approximately 11.72) and a 1.05-fold (95% CI=0.36 to approximately 3.08) increased risk of liver metastases for p53 overexpression-positive and negative colorectal cancers, respectively.

CONCLUSIONThese results demonstrate for the first time that the 72R allele of the p53 polymorphism has an increased risk for liver metastases in colorectal cancers positive for p53 overexpression.

Adenocarcinoma ; genetics ; metabolism ; pathology ; secondary ; Case-Control Studies ; Colorectal Neoplasms ; genetics ; metabolism ; pathology ; DNA, Neoplasm ; blood ; genetics ; Female ; Genes, p53 ; Genetic Predisposition to Disease ; Genotype ; Humans ; Liver Neoplasms ; genetics ; metabolism ; secondary ; Logistic Models ; Male ; Middle Aged ; Multivariate Analysis ; Polymerase Chain Reaction ; Polymorphism, Restriction Fragment Length ; Polymorphism, Single Nucleotide ; Tumor Suppressor Protein p53 ; biosynthesis ; genetics

OBJECTIVETo investigate the roles of p53 in cell cycle changes on human embryo lung fibroblasts (HELF) induced by benzo(a) pyrene[ B(a) P], and relationships between p53 and p21, E2F-1.

METHODSCells transfected with p53 siRNA plasmid (p53-H) and CMV vector (HELF/CMV) were cultured with serum-free R/MINI-1640 for 48 hours, then treated with 2 micromol/L B(a)P for 24 hours. Flow cytometry assay was used for detecting the cell cycle alteration after being exposed to B(a)P. Changes of p53 and p21 expressions were checked using Western blot assay, and the cytoplasmic and nuclear extraction was used to observe the subcellular localizations of p53 and p21. The immunofluorescence assay was used to check changes of E2F-1 expression and the distribution of E2F-1 in nuclear and cytoplasm after exposed to B (a)P. p53siRNA plasmid and the chemical inhibitor of p53 [pifithrin-alpha (PFT)] were used to observe effects of p53 in B(a)P induced cell cycle changes and the relationships of p53 and p21, E2F-1.

RESULTSAfter 2 micromol/L B(a)P exposure, the ratio of G1 phase cells (71 +/- 5)% was decreased to (39 +/- 4)% (P < 0.05). p53, p21 and E2F-1 expressions were increased significantly, and over expressed proteins were mostly located in nuclear after B(a)P treatment. When p53 expression was inhibited by p53 siRNA or PFT, the decreases of G1 phase in response to B(a)P treatment still existed, and over expression of p21 induced by B(a)P was attenuated, especially in nuclear, but E2F-1 over expression was not changed significantly.

CONCLUSIONB(a)P could induce cell cycle changes through p53 independent pathways. And p53 could regulate p21 expression positively, but not E2F-1.

Benzo(a)pyrene ; toxicity ; Cell Cycle ; drug effects ; Cells, Cultured ; Cyclin-Dependent Kinase Inhibitor p21 ; drug effects ; DNA Damage ; E2F1 Transcription Factor ; biosynthesis ; Fibroblasts ; Flow Cytometry ; Gene Expression ; Humans ; Lung ; cytology ; drug effects ; metabolism ; Mechanotransduction, Cellular ; drug effects ; RNA, Messenger ; genetics ; Tumor Suppressor Protein p53 ; genetics ; metabolism

In present study, we investigated the mechanism of regulating HIF-1alpha expression by hydroxysafflor yellow A (HSYA) in Eahy 926 cell line under 1% O2 hypoxia. Eahy 926 cells were incubated with HSYA (100, 10 and 1 micromol x L(-1)) under hypoxia for the indicated time after treatment. Cell proliferation rate was detected using MTT assays. VHL and p53 location and protein expression were analyzed by immunocytochemical stain. HIF-1alpha, VHL and p53 mRNA expression were detected by RT-PCR. Protein expression of HIF-1alpha, VHL and p53 were assayed by Western blotting method. HSYA at 100 micromol x L(-1) increased Eahy 926 cells proliferation rate under hypoxia. HIF-1alpha mRNA and protein expression were up-regulated in the presence of HSYA. VHL, p53 mRNA and protein expression decreased significantly after 8 hours of treatment under hypoxia. HSYA protected Eahy 926 cells from hypoxia, and up-regulated HIF-1alpha expression partially via its inhibition of VHL and p53 expression.
Carthamus tinctorius ; chemistry ; Cell Hypoxia ; Cell Line ; Cell Proliferation ; drug effects ; Chalcone ; analogs & derivatives ; isolation & purification ; pharmacology ; Endothelial Cells ; cytology ; metabolism ; Flowers ; chemistry ; Humans ; Hypoxia-Inducible Factor 1, alpha Subunit ; biosynthesis ; genetics ; Plants, Medicinal ; chemistry ; Quinones ; isolation & purification ; pharmacology ; RNA, Messenger ; metabolism ; Tumor Suppressor Protein p53 ; biosynthesis ; genetics ; Umbilical Veins ; cytology ; Up-Regulation ; Von Hippel-Lindau Tumor Suppressor Protein ; biosynthesis ; genetics