OBJECTIVETo investigate the effect of trans-acting factor(s) on rat glutathione S-transferase P1 gene (rGSTP1) transcription regulation in tumor cells.

METHODSThe binding of trans-acting factor(s) to two enhancers of the rGSTP1 gene, glutathione S-transferase P enhancer I (GPEI) and glutathione S-transferase P enhancer II-1 (GPE II-1), was identified by an electrophoretic mobility shift assay (EMSA). The molecular weight of trans-acting factor was measured in a UV cross-linking experiment.

RESULTSTrans-acting factor interacting with the core sequence of GPEI (cGPEI) were found in human cervical adenocarcinoma cell line (HeLa) and rat hepatoma cell line (CBRH7919). These proteins were not expressed in normal rat liver. Although specific binding proteins that bound to GPE II-1 were detected in all three cell types, a 64 kDa binding protein that exists in HeLa and CBRH7919 cells was absent in normal rat liver.

CONCLUSIONcGPEI, GPEII specific binding proteins expressed in HeLa and CBRH7919 cells may play an important role in the high transcriptional level of the rGSTP1 gene in tumor cells.

Animals ; Carrier Proteins ; metabolism ; Enhancer Elements, Genetic ; physiology ; Gene Expression Regulation, Enzymologic ; Glutathione S-Transferase pi ; Glutathione Transferase ; genetics ; Isoenzymes ; genetics ; Nuclear Proteins ; metabolism ; Rats ; Transcription, Genetic

AIMTo investigate the relationship between glutathione S-transferases gene polymorphism and susceptibility response to hypoxia.

METHODSIn the case-control study, the gene polymorphisms of glutathione S-transferases were tested in Tibetan mountaineers and sea-level Han Chinese by multiple-PCR and PCR-RELP.

RESULTSThe frequency of GSTT1 null genotype was significant different between Tibetan mountaineers and sea-level Han Chinese (P < 0.05), OR = 1.86 (95% CI = 1.01-3.39), and also for GSTP(1-105) mutant genotype in two groups (P < 0.01), OR = 2.19 (95% CI = 1.16-4.13). There was significant difference between A allele and G allele of GSTP(1-105) groups (P < 0.01). There was no difference for GSTM1 null genotype between two groups (P > 0.05), OR = 0.78 (95% CI = 0.43 - 1.42).

CONCLUSIONGSTT1 and GSTP(1-105) genotype may be associated with susceptibility response to altitude hypoxia.

Adult ; Alleles ; China ; Genotype ; Glutathione S-Transferase pi ; genetics ; Glutathione Transferase ; genetics ; Humans ; Hypoxia ; genetics ; Male ; Mountaineering ; Polymorphism, Genetic ; Reactive Oxygen Species ; metabolism ; Young Adult

Carcinoma, Hepatocellular ; genetics ; metabolism ; DNA Methylation ; DNA Restriction Enzymes ; metabolism ; DNA, Neoplasm ; genetics ; Glutathione S-Transferase pi ; genetics ; metabolism ; Humans ; Liver Neoplasms ; genetics ; metabolism ; Polymerase Chain Reaction ; methods

OBJECTIVETo investigate the effect of hairpin small interference RNA (shRNA) on mdr1 and GSTpi protein expression in multidrug resistance human leukemia cell line K562/A02.

METHODThe shRNAs were synthesized targeting the coding region sequences of mdr1 (79 - 99 nt) and GSTpi (308 - 327 nt) respectively, and cloned to plasmid pSilencer2.1-U6 neo. The cloned products pSilence mdr1 and pSilence GSTpi were transfected into K562/A02 cells. Western blot and immunofluorescence analysis were used to detect the effectiveness and the specificity of the gene silence. 50% inhibition concentration (IC(50)) of doxorubicin (ADM) on K562/A02 cells was determined by MTT method.

RESULTpSilence mdr1 and pSilence GSTpi reduced the expression of P-gp and GSTpi protein from 0.75 +/- 0.02 and 0.54 +/- 0.02 to 0.48 +/- 0.05 and 0.39 +/- 0.02 (P < 0.01) respectively, with no effect on alpha-tubulin expression in comparison with the mock treatment. Transfection of pSilence lamin A/C into K562/A02 decreased lamin A/C expression but had no effect on the expression of P-gp and GSTpi. Immunofluorescence assay also showed that shRNAs significantly reduced the P-gp and GSTpi positive cells from (71.25 +/- 9.65)% and (81.25 +/- 6.49)% to (35.25 +/- 5.97)% and (41.25 +/- 4.43)% (P < 0.01), respectively, compared with the mock treatment. The resistance indexes after transfection were decreased to 8 (pSilence mdr1) and 10 (pSilence GSTpi) respectively from 23 (mock transfection) (P < 0.01).

CONCLUSIONThe shRNA could effectively and specifically reverse the multidrug resistance on K562/A02 cell line.

ATP-Binding Cassette, Sub-Family B, Member 1 ; genetics ; metabolism ; Drug Resistance, Multiple ; genetics ; Drug Resistance, Neoplasm ; genetics ; Glutathione S-Transferase pi ; genetics ; metabolism ; Humans ; K562 Cells ; RNA Interference ; RNA, Messenger ; genetics ; RNA, Small Interfering ; genetics ; Transfection

We have investigated the susceptibility of rat lung's GSTP1 gene to hypobaric hypoxia and explored its role in the body's possible adaptation mechanism at the moleuclar lever. Thirty male SD rats were randomly divided into five groups(0,1,3,5 and 7 d) and were exposed for 12 h per day at a simulating altitude of 7000 +/- 50 m in a hypobaric hypoxia chamber with 1 h's rest after 6 h's exposure. Then the expression of GSTP1 mRNA in the lung tissue of SD rats was examined using fluorescence quantitative RT-PCR. Meanwhile the activity of glutathione S-transferases (GSTs) enzyme and the change of maleic dialdehyde (MDA) in the lung tissue of SD rats were determined using spectrophotometer. In comparison with the non-exposure group,the expression of GSTP1 gene showed statistically significant differnce from the first to the seventh day (P<0.05). The level of GSTs decreased and MDA increased from the first to the seventh day (P<0.05). In conclusion, GSTP1 gene is susceptible to hypobaric hypoxia and may be a new marker of gene screening for the body's adaptation to special environment.
Animals ; Biomarkers ; analysis ; Glutathione S-Transferase pi ; analysis ; biosynthesis ; genetics ; Hypoxia ; genetics ; metabolism ; Lung ; metabolism ; Male ; RNA, Messenger ; analysis ; biosynthesis ; genetics ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Reverse Transcriptase Polymerase Chain Reaction

OBJECTIVE: To design short hairpin RNA (shRNA) interference sequence to silence glutathione S-transferase P1 (GSTP1) gene of androgen independent prostate cancer cell line DU145, and to explore its effect on proliferation and sensitivity to chemotherapeutics. METHODS: The target sequence was picked up to form the shRNA, and the 3 shRNA expression vectors were shRNA255, shRNA554 and shRNA593. The DNA template was cloned to plasmid pGPU6/GFP/Neo. The shRNA was identified by enzyme digesting and gene sequencing. The screening experiment was done to pick up the shRNA expression vector with the highest transfection ratio and best gene silencing results. DU145 cells were divided into a blank plasmid group and a shRNA transfected group. According to the chemotherapeutics the DU145 cells were divided into a fluorouracil (FU) group and a paclitaxel (PA) group, and the 2 groups were subdivided into 4 subsets according to the chemotherapeutic concentrations (FU: 30, 60, 120, and 240 μg/mL; PA: 0.2, 2, 10, and 20 μg/mL), meanwhile a blank control group was included respectively. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay was used to evaluate the proliferation after the transfection. MTT and terminal de-oxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay were used to detect the inhibition effect of different concentrations of 5-FU or PA on the proliferation and induction of apoptosis of DU145. RESULTS: The transfection ratio of the 3 shRNA expression vectors (shRNA255, shRNA554, and shRNA593) was (63.30±1.04)%, (76.20±0.68)%, and (72.70±0.33)%, and the transfection ratio of shRNA554 was the highest. there was significant difference among the above 3 shRNA expression vectors (P<0.01). After the transfection, the mRNA was 128.31±2.50, 43.24±4.30 and 85.62±6.30, the GSTP1 protein was 163.92±12.40, 65.38±9.30 and 114.25±16.70. After the transfection of shRNA554, the mRNA and protein of GSTP1 were the lowest level. there was significant difference among the above 3 shRNA expression vector (P<0.01). MTT analysis showed that before the transfection, the survival ratio of cells under different concentrations of FU (30, 60, 120, and 240 μg/mL) was (95.60±2.11)%, (90.20±0.86)%, (83.10±3.12)% and (74.60±1.32)%; however after the transfection, the survival ratio of cells was (91.30±1.43)%, (84.60±2.13)%, (73.20±1.52)%, and (65.5±0.942)%. TUNEL assay showed that before the transfection, the apoptosis ratio of cells under different concentrations of FU (30, 60, 120, and 240 μg/mL) was (5.50±0.88)%, (10.20±1.64)%, (15.20±2.39)%, and (25.10±2.59)%; however after the transfection, the apoptosis ratio of cells was (10.8±0.62)%, (15.7±1.32)%, (20.4±1.89)%, and (34.9±2.54)%. After the transfection, the cell survival ratio decreased under the same concentration of FU, and the apoptosis ratio increased, with statistical significance (both P<0.01). MTT analysis showed that before the transfection, the survival ratio of cells under different concentrations of PA (0.2, 2, 10, and 20 μg/mL) was (98.50±2.34)%, (95.20±1.32)%, (89.40±0.68)%, and (82.70±1.73)%; after the transfection the survival ratio of cells was (94.20±0.78)%, (86.50±2.13)%, (78.70±1.34)%, and (70.10±0.76)%. TUNEL assay showed that before the transfection, the apoptosis ratio of cells under different concentrations of PA (0.2, 2, 10, and 20 μg/mL) were (2.40±1.07)%, (5.20±1.33)%, (10.50±2.41)%, (20.70±1.92)%; after the transfection the apoptosis ratio of cells was (5.46±2.13)%, (13.80±1.24)%, (21.20±2.39)%, and (29.20±2.21)%. After the transfection, the cell survival ratio decreased under the same PA concentration, and the apoptosis ratio increased, with statistical significance (both P<0.01). CONCLUSION gene GSTP1 silence via shRNA transfection to androgen independent prostate cancer cell line DU145 can inhibit its proliferation in time dependent manner, and induce apoptosis and raise its sensitivity to chemotherapeutics.
Androgens ; metabolism ; Antineoplastic Agents ; pharmacology ; Apoptosis ; genetics ; Cell Line, Tumor ; Cell Proliferation ; Gene Silencing ; Glutathione S-Transferase pi ; genetics ; Humans ; Male ; Prostatic Neoplasms ; genetics ; pathology ; RNA Interference ; RNA, Small Interfering ; genetics ; Transfection

OBJECTIVETo explore the correlation of chemotherapy efficacy in tongue squamous cell carcinoma(SCC) with expression level of P-glycoprotein(Pgp), multidrug resistance-associated protein (MRP), lung resistance-related protein (LRP), glutathiones-tranferase (GST-pi), DNA topo-isomerase II alpha (Topo II alpha).

METHODSThe expression patterns of Pgp, MRP, LRP, GST-pi and Topo II alpha in 40 patients (pre and post-chemotherapy, respectively) with tongue SCC were examined by immunohistochemically labelled streptavidin bioein method (LsAB).

RESULTSThe expression ratios of Pgp, MRP, LRP, GST-pi and Topo II alpha in pre-chemotherapy cases were 47.5%, 50%, 35%, 45%, 82.5%, respectively. No relations between expression of Pgp, MRP, LRP, GST-pi, Topo II alpha and clinic indexes were established (P > 0.05). Expression ratios of Pgp, MRP in post-chemotherapy cases were higher than that in pre-chemotherapy cases (P < 0.05). Expression of Pgp and MRP showed relevance with drug resistance (P < 0.05). The co-expression was common, the ratios of co-expression of Pgp, MRP, GST-pi and MRP, GST-pi in chemotherapy non-responders were 40% and 50%, respectively, but 0 in responders.

CONCLUSIONThe intrinsic multidrug resistance of tongue SCC is relevant to the effects of Pgp, MRP, GST-pi.

ATP-Binding Cassette, Sub-Family B, Member 1 ; biosynthesis ; genetics ; Adult ; Antigens, Neoplasm ; Carcinoma, Squamous Cell ; metabolism ; DNA Topoisomerases, Type II ; biosynthesis ; genetics ; DNA-Binding Proteins ; Female ; Glutathione S-Transferase pi ; Glutathione Transferase ; biosynthesis ; genetics ; Humans ; Isoenzymes ; biosynthesis ; genetics ; Male ; Middle Aged ; Multidrug Resistance-Associated Proteins ; biosynthesis ; genetics ; Neoplasm Proteins ; biosynthesis ; genetics ; Random Allocation ; Tongue Neoplasms ; metabolism ; Vault Ribonucleoprotein Particles ; biosynthesis ; genetics

OBJECTIVETo study the reversal effect of nomegestrol acetate (NOM) on mutidrug resistance (MDR) in MCF7/ADR and its mechanism.

METHODSUsing tetrazolium dye assay, effects of various concentrations of NOM on sensitivity to ADR in MCF7/ADR was studied. Expression of MDR related genes MDR1, glutathoine S-transferase Pi (GSTpi), Topoisomerase II alpha (Topo II alpha) and MDR related protein (MRP) were assayed by reverse transcription-polymerase chain reaction (RT-PCR) and immunocytochemistry assay. Using flow cytometry (FCM), intracellular ADR concentration effects on cell cycle were observed.

RESULTSNOM significantly reversed MDR in MCF7/ADR. After NOM 20, 10 and 5 micromol/L treatment, the chemosensitivity to ADR increased to 21, 12 and 8 times. The reversal activity of NOM was stronger than that of the precursor compound megestrol acetate, and was comparable to that of verapamail. After treatment with NOM 5 micromol/L both MDR1 and GSTpi mRNA genes expression began to decline on D2 (P < 0.05, & P < 0.01) and reached the lowest level on D3 (both P < 0.01), but the expression levels began to rise on D6 again (both P < 0.05). The expression of MRP and Topo II alpha gave no significant change. Changes of P-gp and GSTpi protein expressions were similar to those of their mRNA expressions, showing early decline and late rise. Two hours after NOM 20, 10, and 5 micromol/L treatment, intracellular ADR concentration increased 2.7, 2.3 and 1.5 times, respectively. FCM data showed that after forty-eight hours, combined administration of NOM (20 micromol/L) and ADR (from low concentration to high concentration), MCF7/ADR cells showed gradual arrest in the G(2)M phase with the increase of ADR dose.

CONCLUSIONNOM has strong reversal effects on MDR in MCF7/ADR. The reversal takes place via different routes, i.e. down regulating mRNA and protein expression levels of MDR1 and GSTpi, increasing intracellular drug concentration, and enhancing the arrest of ADR in cells at G(2)M phase.

ATP-Binding Cassette, Sub-Family B, Member 1 ; genetics ; metabolism ; Antigens, Neoplasm ; Breast Neoplasms ; genetics ; pathology ; Cell Survival ; drug effects ; DNA Topoisomerases, Type II ; genetics ; metabolism ; DNA-Binding Proteins ; Drug Resistance, Neoplasm ; genetics ; Gene Expression Regulation, Neoplastic ; drug effects ; Glutathione S-Transferase pi ; Glutathione Transferase ; genetics ; metabolism ; Humans ; Immunohistochemistry ; Inhibitory Concentration 50 ; Isoenzymes ; genetics ; metabolism ; Megestrol ; Multidrug Resistance-Associated Proteins ; genetics ; metabolism ; Norpregnadienes ; pharmacology ; Progesterone Congeners ; pharmacology ; RNA, Messenger ; drug effects ; genetics ; metabolism ; Reverse Transcriptase Polymerase Chain Reaction ; Tumor Cells, Cultured ; Verapamil ; pharmacology

BACKGROUND: Glutathion S-transferase P1 (GSTP1), the abundant isoform of glutathione S-transferase in lung epithelium, plays an important role in cellular protection against oxidative stress and toxic foreign chemicals. GSTP1 (Ile105Val) polymorphism has been reported to be associated with asthma related phenotypes such as atopy and bronchial hyperresponsiveness. Therefore we investigated whether this polymorphism may be associated with the development of aspirin-intolerant asthma (AIA). METHODS: GSTP1 Ile105Val polymorphism was determined using a single based extension method in 88 AIA subjects and compared to 154 aspirin-tolerant asthma (ATA) subjects and 119 normal healthy controls (NC) recruited from the Korean population. RESULTS: No significant differences in allele and genotype frequencies of the GSTP1 Ilel105Val polymorphism were observed in the three groups (p> 0.05). However, minor G allele frequency of the GSTP1 Ilel105Val polymorphism in AIA group (16.5%) tended to be lower than in the NC group (20.6%). CONCLUSION: These results suggest a lack of association of the GSTPI Ilel105Val gene polymorphism with AIA phenotype in the Korean population [word count: 159].
Polymorphism, Restriction Fragment Length ; Polymorphism, Genetic ; Male ; Korea ; Isoenzymes/*genetics ; Humans ; Glutathione S-Transferase pi/*genetics/*metabolism ; Glutathione/*metabolism ; Genotype ; Female ; Case-Control Studies ; Asthma/*chemically induced/enzymology/*genetics ; Aspirin/*adverse effects ; Anti-Inflammatory Agents, Non-Steroidal/*adverse effects ; Alleles ; Adult

OBJECTIVETo study the expression and clinical significance of P-gp, GST-pi and Topo II alpha in gastric and colorectal cancers.

METHODSThe expression of P-gp, GST-pi and Topo II alpha in 83 cases with gastric or colorectal cancer were examined by immunohistochemistry S-P.

RESULTSThe positive expression rates of P-gp, GST-pi, Topo II alpha in normal tissue and gastric and colorectal cancers were 69.9%, 65.1%, 50.6% and 83.1%, 85.5%, 45.8%, respectively. The positive rates of P-gp and GST-pi in gastric and colorectal cancer were significantly higher than those in normal gastric and colorectal tissue (P < 0.05). The expression of Topo II alpha in poorly differentiated cancers was significantly higher than that in well-and moderately differentiated cancers. There was no correlation between other items and clinicopathological parameters (P > 0.05).

CONCLUSIONP-gp, GST-pi and Topo II alpha play important role in multidrug resistance. Their mechanisms of drug resistance were different. The detection of expression of P-gp, GST-pi and Topo II alpha has an important guiding significance in chemotherapy for gastric and colorectal cancers.

ATP-Binding Cassette, Sub-Family B, Member 1 ; biosynthesis ; genetics ; Adenocarcinoma ; metabolism ; Adult ; Aged ; Aged, 80 and over ; Antigens, Neoplasm ; biosynthesis ; genetics ; Colorectal Neoplasms ; metabolism ; DNA Topoisomerases, Type II ; biosynthesis ; genetics ; DNA-Binding Proteins ; biosynthesis ; genetics ; Drug Resistance, Neoplasm ; Female ; Gastrointestinal Neoplasms ; metabolism ; Glutathione S-Transferase pi ; biosynthesis ; genetics ; Humans ; Immunohistochemistry ; Male ; Middle Aged ; Stomach Neoplasms ; metabolism