2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) can induce drug transporter genes such as the ATP-binding cassette G member 2 (ABCG2), which contributes to multidrug resistance. We investigated the effect of TCDD pretreatment on drug transporters induction from cancer cells of various origins. Cell viabilities after treatment of cisplatin were measured to evaluate acquiring cisplatin resistance by TCDD. Acquring cisplatin resistance was found only in cisplatin senstivie cancer cells including gastric SNU601, colon LS180, brain CRT-MG and lymphoma Jurkat cells which showed a significant increase in cell viability after combined treatment with TCDD and cisplatin. High increase of ABCG2 gene expression was found in SNU601 and LS180 cells with a mild increase in the expression of the ABCC3, ABCC5,and SLC29A2 genes in SNU601 cells, and of major vault protein (MVP) in LS180 cells. The AhR inhibitor kaempferol suppressed the upregulation of ABCG2 expression and reversed the TCDD-induced increase in cell viability in LS180 cells. However, in CRT-MG cells, other transporter genes including ABCC1, ABCC5, ABCA3, ABCA2, ABCB4, ABCG1, and SLC29A1 were up-regulated. These findings suggested the acquiring cisplatin resistance by TCDD associated with cancer cell-type-specific induction of drug transporters.
ATP-Binding Cassette Transporters/genetics/*metabolism ; Cell Line, Tumor ; Cell Survival/drug effects ; Cisplatin/*pharmacology ; Drug Resistance, Neoplasm/drug effects ; Equilibrative-Nucleoside Transporter 2/genetics/metabolism ; Humans ; Jurkat Cells ; K562 Cells ; Kaempferols/pharmacology ; Multidrug Resistance-Associated Proteins/genetics/metabolism ; Neoplasm Proteins/genetics/*metabolism ; RNA, Messenger/metabolism ; Receptors, Aryl Hydrocarbon/metabolism ; Tetrachlorodibenzodioxin/*pharmacology ; Up-Regulation/*drug effects ; Vault Ribonucleoprotein Particles/genetics/metabolism

2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) can induce drug transporter genes such as the ATP-binding cassette G member 2 (ABCG2), which contributes to multidrug resistance. We investigated the effect of TCDD pretreatment on drug transporters induction from cancer cells of various origins. Cell viabilities after treatment of cisplatin were measured to evaluate acquiring cisplatin resistance by TCDD. Acquring cisplatin resistance was found only in cisplatin senstivie cancer cells including gastric SNU601, colon LS180, brain CRT-MG and lymphoma Jurkat cells which showed a significant increase in cell viability after combined treatment with TCDD and cisplatin. High increase of ABCG2 gene expression was found in SNU601 and LS180 cells with a mild increase in the expression of the ABCC3, ABCC5,and SLC29A2 genes in SNU601 cells, and of major vault protein (MVP) in LS180 cells. The AhR inhibitor kaempferol suppressed the upregulation of ABCG2 expression and reversed the TCDD-induced increase in cell viability in LS180 cells. However, in CRT-MG cells, other transporter genes including ABCC1, ABCC5, ABCA3, ABCA2, ABCB4, ABCG1, and SLC29A1 were up-regulated. These findings suggested the acquiring cisplatin resistance by TCDD associated with cancer cell-type-specific induction of drug transporters.
ATP-Binding Cassette Transporters/genetics/*metabolism ; Cell Line, Tumor ; Cell Survival/drug effects ; Cisplatin/*pharmacology ; Drug Resistance, Neoplasm/drug effects ; Equilibrative-Nucleoside Transporter 2/genetics/metabolism ; Humans ; Jurkat Cells ; K562 Cells ; Kaempferols/pharmacology ; Multidrug Resistance-Associated Proteins/genetics/metabolism ; Neoplasm Proteins/genetics/*metabolism ; RNA, Messenger/metabolism ; Receptors, Aryl Hydrocarbon/metabolism ; Tetrachlorodibenzodioxin/*pharmacology ; Up-Regulation/*drug effects ; Vault Ribonucleoprotein Particles/genetics/metabolism

BACKGROUNDBoth survivin and lung resistance related protein (LRP) are related to the chemoresistances in hepatocellular carcinoma (HCC). But the relationship between survivin and LRP is indefinite. The aim of this study was to investigate the effects of down-regulation of survivin on LRP expressions and the reversal of chemoresistances in HCC both in vitro and in vivo.

METHODSThe expressions of survivin were detected by RT-PCR and Western blotting in HCC cell line SMMC-7721 and SMMC-7721/ADM. The sensitivities of these two cell lines to ADM were evaluated by MTT assays. SiRNA which targeted survivin was transfected into SMMC-7721/ADM cells, then the sensitivity of SMMC-7721/ADM cells to ADM and the expressions of survivin and LRP were detected respectively. SMMC-7721/ADM cells were transplanted subcutaneously into nude mice to establish xenograft tumors. Antitumor activities of RNA interference (RNAi) targeting survivin, various doses of ADM and combination therapies were observed respectively. Possible toxicities were evaluated. LRP expression changes were tested. Student's t test was used for evaluating statistical significance.

RESULTSThe expressions of survivin in SMMC-7721/ADM cell line showed significant elevation compared to those in SMMC-7721 cell line (P < 0.05). Positive siRNA down-regulated the expressions of survivin significantly (P < 0.05). SiRNA targeting survivin could sensitize SMMC-7721/ADM cells to ADM and down-regulate the expressions of LRP significantly (P < 0.05). Growths of the tumors were significantly inhibited in positive siRNA group as compared with those in the control group from the 8th day (P < 0.05). Combination therapies caused significant tumor inhibitions compared with tumors of nude mice in the other three groups respectively (P < 0.05). No toxicities were found in nude mice treated by siRNA and combination therapies. The expressions of LRP were markedly reduced in tumors treated with siRNA targeting survivin (P < 0.05).

CONCLUSIONSDown regulation of survivin gene by RNAi can increase chemosensitivity of HCC both in vitro and in vivo. The reversal of drug resistance may be reduced through the inhibitions of LRP.

Animals ; Antineoplastic Combined Chemotherapy Protocols ; therapeutic use ; Blotting, Western ; Carcinoma, Hepatocellular ; drug therapy ; genetics ; metabolism ; Cell Line, Tumor ; Doxorubicin ; therapeutic use ; Drug Resistance, Neoplasm ; Humans ; Inhibitor of Apoptosis Proteins ; Mice ; Mice, Inbred BALB C ; Mice, Nude ; Microtubule-Associated Proteins ; genetics ; metabolism ; Mitolactol ; therapeutic use ; Mitomycins ; therapeutic use ; RNA Interference ; physiology ; RNA, Small Interfering ; genetics ; physiology ; Reverse Transcriptase Polymerase Chain Reaction ; Vault Ribonucleoprotein Particles ; genetics ; metabolism ; Xenograft Model Antitumor Assays

OBJECTIVETo explore the expression and clinical significance of P-glycoprotein (P-gp)/mdr1mRNA, multidrug resistance-associated protein (MRP) and lung resistance protein (LRP) in newly diagnosed non-Hodgkin's lymphoma.

METHODSmdr1 mRNA of in 41 patients with non-Hodgkin's lymphoma was assayed by semi-quantitative RT-PCR. The expressions of P-gp, MRP and LRP proteins in lymph node viable blasts were identified by flow cytometry. The results were compared with those obtained from control cases, and the correlation of the changes with clinical outcomes was analyzed.

RESULTS(1) Among the 41 cases, the positive expression of P-gp protein was detected in 8 cases, MRP in 7 cases, LRP in 15 cases, and mdr 1 mRNA in 11 cases. (2) The P-gp and LRP levels in NHL were significantly higher than those in control group, but MRP wasn't. The P-gp over-expression was significantly associated with mdr1mRNA (r = 0.396, P = 0.01). No correlation was showed among the expressions of P-gp, MRP and LRP. (3) Patients with P-gp expression had a poorer outcome of chemotherapy than those with P-gp-negative (P = 0.005). P-gp expression was significantly associated with higher clinical stage (P = 0.046) and elevated serum lactate dehydrogenase level (P = 0.032), but not associated with malignant degree (P = 0.298). MRP had no impact on the outcome of chemotherapy (P = 0.212), and wasn't significantly associated with higher clinical stage (P = 0.369), elevated LDH (P = 0.762) and higher malignant degree (P = 0.451). Patients with LRP expression had a poorer outcome of chemotherapy than those LRP-negative (P = 0.012). LRP expression was significantly associated with higher clinical stage (P = 0.0019), elevated LDH (P = 0.02) and higher malignant degree (P = 0.01).

CONCLUSIONThe data of this study indicate that P-gp and LRP expressions but not MRP expression are important in the mechanism of drug resistance associated with a poor clinical outcome in previously untreated NHL.

ATP Binding Cassette Transporter, Sub-Family B ; ATP-Binding Cassette, Sub-Family B, Member 1 ; genetics ; metabolism ; Adolescent ; Adult ; Aged ; Antineoplastic Combined Chemotherapy Protocols ; therapeutic use ; Cell Line, Tumor ; Child ; Drug Resistance, Multiple ; Drug Resistance, Neoplasm ; Female ; Humans ; Lactate Dehydrogenases ; blood ; Lymph Nodes ; metabolism ; Lymphoma, Non-Hodgkin ; drug therapy ; metabolism ; pathology ; Male ; Middle Aged ; Multidrug Resistance-Associated Proteins ; metabolism ; Neoplasm Staging ; RNA, Messenger ; metabolism ; Remission Induction ; Vault Ribonucleoprotein Particles ; metabolism ; Young Adult

OBJECTIVETo explore the pharmacologic effects of Chinese medicine Bushen Huayu Jiedu Compound Recipe (BSHYJDR) in drug-resistance cells of lung cancer.

METHODSHuman lung adenocarcinoma A549/DDP cell strain was selected, serum pharmacology and flow cytometer (FCM) method were adopted, S180 tumor-bearing mice and normal mice were given, through gastrogavage, different doses of a decocted concentration of BSHYJDR. Serum from the abdominal aorta was taken to observe the effect of drug-serum on cisplatin (DDP) concentration, free Ca2+ concentration and the expression of lung drug-resistance protein LRP-56 in A549/DDP cells.

RESULTSCompared with the drug-resistance group, the intracellular DDP concentration in the group taking a high dose and the normal group of Chinese medicine showed significant difference (P<0.05), while no significant difference was found in the low-dose group (P>0.05). Compared with the drug-resistance group, the Ca2+ concentration in cells and the expression of LRP in lung cancer drug-resistance cells A549/DDP of the high-dose group, the low-dose group and the normal group of Chinese medicine were significantly different (all P<0.01), the LRP expression of the normal group was obviously higher than that of the drug-resistance group (P<0.05).

CONCLUSIONIt was indicated that serum containing Chinese medicine BSHYJDR in the tumor-bearing mice and the normal mice had certainly different, tumor-bearing mice serum containing could improve drug concentration in lung cancer drug-resistance cells, prevent the inflow and release of Ca2+, and inhibit the expression of the drug-resistance gene in the lung cancer drug-resistance cells, which might be the mechanism of BSHYJDR in enhancing the efficacy in reversing and inhibiting tumor.

Animals ; Calcium ; metabolism ; Cell Line, Tumor ; Cisplatin ; pharmacology ; Drug Resistance, Neoplasm ; Humans ; Lung Neoplasms ; drug therapy ; pathology ; Medicine, Chinese Traditional ; Mice ; Vault Ribonucleoprotein Particles ; genetics

This study was purposed to investigate the relationship of expressions of gluthatione-S-transferase-pi (GST-pi), multidrug resistance protein-1 (MRP-1), lung resistance protein (LRP) with multidrug resistance of acute leukemia (AL), the correlation between 3 kinds protein expressions and the correlation of their protein expression with clinical features of AL patients. The S-P immunohistochemical staining method was used to determine the expressions of GST-pi, MRP1 and LRP proteins in 80 AL patients and 30 normal subjects. The results showed that there was the correlation between GST-pi, MRP1, LRP protein expression and chemotherapy resistance, meanwhile CR rates of patients with positive expression of those proteins were lower than that of patients with negative expression (P<0.05), so those protein expressions may be accounted for poor prognosis. There was the positive relationship between expression of GST-pi and MRP1 in refractory group (r=0.851, P<0.01). It is concluded that co-examination of GST-pi and MRP1 has greater significance than examination of one kind of protein in evaluating poor prognosis of leukemia patients. LRP protein expression increase obviously when WBC counts >or= 10 x 10(9)/L (63.6%, P<0.05), therefore LRP protein has great judging value for evaluating drug resistance and prognosis of acute leukemia patients whose peripheral blood WBC counts were high.
ATP-Binding Cassette, Sub-Family B, Member 1 ; biosynthesis ; genetics ; Adolescent ; Adult ; Aged ; Drug Resistance, Multiple ; genetics ; Drug Resistance, Neoplasm ; genetics ; Female ; Glutathione S-Transferase pi ; biosynthesis ; genetics ; Humans ; Leukemia, Myeloid, Acute ; drug therapy ; metabolism ; Male ; Middle Aged ; Precursor Cell Lymphoblastic Leukemia-Lymphoma ; drug therapy ; metabolism ; Vault Ribonucleoprotein Particles ; biosynthesis ; genetics

OBJECTIVETo investigate synergistic effect of bromocriptine (BCT) combining tumor necrosis factor-alpha (TNF-alpha) on reversing multidrug resistance in a nude mouse model of liver neoplasm.

METHODSHuman hepatocarcinoma cell line HepG(2) (HepG(2) group), drug resistant hepatocarcinoma cell line HepG(2)/adriamycin (HepG(2)/ADM group) and hepatocarcinoma cell line transfected with TNF-alpha gene HepG(2)/ADM/TNF (TNF group and BCT group) were injected into the liver of nude mice via orthotopic implantation to establish multidrug resistance model of liver neoplasm in vivo. All the mice were injected with 5-fluouracil + adriamycin + mitomycin in abdominal cavity for 7 d. The mice in BCT group was simultaneously given bromocriptine through gastric canal. Size and weight of the tumor were measured. Furthermore tumor histological character and growth of the nude mice was observed and its chemosensitivity was tested. MDR associated genes and proteins (MRP, LRP) of implanted tumors were detected by immunohistochemical staining and reverse transcriptive polymerase chain reaction (RT-PCR), and apoptosis rate of hepatocarcinoma cells was detected by TUNEL assay.

RESULTSThe nude mouse model of each cell line was all inoculated successfully. The tumor growth rate and weight were significantly different among groups (P < 0.05). After chemotherapy tumor growth inhibition rate was higher in BCT group (67%) compared to ADM and TNF groups (P < 0.01), and similar to HepG(2) group (54%). MDR1 and LRP mRNA could be detected in all groups, but TNF-alpha was detected only in TNF-alpha and BCT groups. Furthermore, MDR1 and LRP protein expression of tumors in TNF-alpha and BCT groups was low similar to HepG(2) group. The apoptosis rate of hepatocarcinoma cells was much higher in BCT group than in other groups (P < 0.05) with TUNEL assay.

CONCLUSIONSTNF-alpha gene can down-regulate the MDR associated genes and proteins expression for example MDR1, LRP, and lower its tumorgenesis. Moreover, bromocriptine can enhance the susceptibility of HepG(2)/ADM cells to cytotoxic drugs.

Animals ; Bromocriptine ; pharmacology ; Cell Line, Tumor ; Drug Resistance, Multiple ; drug effects ; genetics ; Drug Resistance, Neoplasm ; drug effects ; genetics ; Drug Synergism ; Female ; Humans ; Liver Neoplasms, Experimental ; metabolism ; therapy ; Male ; Mice ; Mice, Nude ; Multidrug Resistance-Associated Proteins ; biosynthesis ; genetics ; Neoplasm Transplantation ; Transfection ; Tumor Necrosis Factor-alpha ; genetics ; pharmacology ; Vault Ribonucleoprotein Particles ; biosynthesis ; genetics

ATP Binding Cassette Transporter, Sub-Family B ; metabolism ; Apoptosis ; genetics ; Carcinoma, Non-Small-Cell Lung ; genetics ; metabolism ; pathology ; Genes, MDR ; Humans ; Lung Neoplasms ; genetics ; metabolism ; pathology ; Proto-Oncogene Proteins c-bcl-2 ; metabolism ; RNA, Messenger ; biosynthesis ; genetics ; Telomerase ; biosynthesis ; genetics ; Tumor Suppressor Protein p53 ; metabolism ; Vault Ribonucleoprotein Particles ; metabolism

OBJECTIVETo investigate the role of lung resistance-related protein (LRP) in intrinsic multidrug resistance (MDR) of bladder cancer and detect the relationship of LRP expression with the clinical pathologic parameters.

METHODS66 patients were studied with newly diagnosed primary bladder cancer (T(a) = 12, T(1) = 26, T(2) = 11, T(3) = 10, T(4) = 7; G(1) = 35, G(2) = 19, G(3) = 12). No patient was treated preoperatively with either radiation or chemotherapy. Reverse transcription-polymerase chain reaction (RT-PCR) was performed for measure of mRNA expression for LRP, multidrug-resistance gene 1 (MDR1), and multidrug resist nce-associated protein 1 (MRP1). Expressions of LRP, P53 and P63 proteins were examined by immunohistochemistry staining.

RESULTSLRP mRNA had the highest expression rate (64%, 42/66) among three MDR markers in primary bladder cancers without chemotherapy and its level was significantly higher in normal bladder tissue than in TCC of bladder (t = 2.82, P < 0.01), in low grade than in high grade cancers (t = 4.14, P < 0.01), and in superficial than in invasive cancers (t = 3.58, P < 0.05). LRP mRNA expression showed no correlation with either MDR1 or MRP1, but close correlation with LRP protein level (r = 0.89, P < 0.01). LRP was associated with low-grade (r = 0.81, P < 0.01) and low-stage (r = 0.78, P < 0.05) cancers, but not with tumor suppressor P53 or P63 (P > 0.05).

CONCLUSIONSThe grade and stage-related expression pattern of LRP indicates that it may be a predictive index for intrinsic MDR in bladder cancer. Anti-cancer drugs out of the MDR spectrum of LRP may be more effective for patients with early bladder cancer.

ATP-Binding Cassette, Sub-Family B, Member 1 ; biosynthesis ; genetics ; Adult ; Aged ; Carcinoma, Transitional Cell ; genetics ; metabolism ; pathology ; Drug Resistance, Multiple ; Drug Resistance, Neoplasm ; Female ; Humans ; Immunohistochemistry ; Male ; Middle Aged ; Multidrug Resistance-Associated Proteins ; biosynthesis ; genetics ; Neoplasm Proteins ; biosynthesis ; genetics ; RNA, Messenger ; genetics ; Reverse Transcriptase Polymerase Chain Reaction ; Urinary Bladder Neoplasms ; genetics ; metabolism ; pathology ; Vault Ribonucleoprotein Particles ; biosynthesis ; genetics

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