OBJECTIVETo investigate inhibitory effect of short interfering RNA (siRNA) on the expression of lung resistance-related protein (LRP) in leukemia cells.

METHODSThe eukaryotic vectors of LRP, pcDNA3.0/LRP, were constructed. The transfection protocol of K562 cells grown in standard conditions consisted of different combinations of pcDNA3.0/LRP, pEGFP-C1 expressing mammalian enhanced green fluorescent protein (GFP), and their gene-specific siRNAs. RT-PCR and flow cytometry were employed to evaluate the mRNA and protein expression of LRP and fluoroscopy was performed for assay of GFP expression in the transfected cells.

RESULTSCompared with untreated K562 cells, pcDNA3.0/LRP-transfected cells showed increased LRP mRNA and protein expression and the positive cell percentage reached 30%. In the cells co-transfected with LRP gene-specific siRNA and pcDNA3.0/LRP, both LRP mRNA and protein expression decreased significantly to a level defined as negative results; the GFP expression showed no significant difference between the cells transfected with pEGFP-C1 and those co-transfected with LRP gene-specific siRNA and pEGFP-C1. LRP mRNA and protein expressions were also similar between the cells transfected with pcDNA3.0/LRP and those co-transfected with GFP gene-specific siRNA and pcDNA3.0/LRP.

CONCLUSIONSThe LRP gene-specific siRNA we designed is capable of degrading LRP mRNA and inhibiting the protein expression effectively and specifically, which shed light on the potential application of siRNA for gene-specific therapy to reverse LRP-induced multidrug resistance of leukemia cells.

Drug Resistance, Multiple ; genetics ; Genetic Therapy ; Green Fluorescent Proteins ; biosynthesis ; genetics ; Humans ; K562 Cells ; RNA, Messenger ; biosynthesis ; genetics ; RNA, Small Interfering ; genetics ; Transfection ; Vault Ribonucleoprotein Particles ; biosynthesis ; genetics

OBJECTIVETo study the effect of cyclooxygenase -2 selective inhibitor celecoxib on the expression of major vault protein ( MVP) in the brain of rats with status epilepticus and its possible roles in the treatment of refractory epilepsy.

METHODSSixty adult male Sprague-Dawley rats were randomly assigned to blank control (n=16), epilepsy model (n=22) and celecoxib treatment groups (n=22). After the status epilepticus was induced in rats by injecting lithium and pilocarpine, each group had 16 rats enrolled as subjects. Immunohistochemical method and Western blot method were used to detect the expression of MVP in the frontal cortex and hippocampus.

RESULTSThe expression of MVP was significantly higher in the epilepsy model group than in the control group (P<0.01). The expression of MVP in the celecoxib treatment group was significantly decreased compared with the epilepsy model group, but it was still higher than in the control group (P<0.01).

CONCLUSIONSCelecoxib could decrease the expression of MVP in brain tissue of rats with status epilepticus, suggesting that it is promising for the treatment of intractable epilepsy.

Animals ; Blotting, Western ; Brain ; metabolism ; Celecoxib ; pharmacology ; therapeutic use ; Cyclooxygenase 2 Inhibitors ; pharmacology ; Immunohistochemistry ; Male ; Rats ; Rats, Sprague-Dawley ; Status Epilepticus ; drug therapy ; metabolism ; Vault Ribonucleoprotein Particles ; analysis

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

Acute Disease ; Adolescent ; Child ; Child, Preschool ; Drug Resistance, Multiple ; genetics ; Drug Resistance, Neoplasm ; genetics ; Female ; Gene Expression Regulation, Neoplastic ; Humans ; Leukemia ; physiopathology ; Male ; Neoplasm Proteins ; genetics ; RNA, Messenger ; genetics ; metabolism ; Reverse Transcriptase Polymerase Chain Reaction ; Vault Ribonucleoprotein Particles ; genetics

This study was aimed to detect the glutathione S-transferase-π (GST-π) and lung resistance-related protein (LRP) genes and to investigate their relationship with multidrug resistance (MDR) of patients with acute leukemia (AL). Real-time fluorescent quantitative reverse transcription polymerase chain reaction (RQ-PCR) was used to detect the expression of GST-π and LRP genes in peripheral blood mononuclear cells from 44 AL patients and 27 normal subjects. The results showed that the significant difference in GST-π expression level was found between newly diagnosed patients and complete remission patients and between refractory patients and complete remission patients (P < 0.01), while expression level of LRP genes showed obvious difference (P ≤ 0.01) between newly diagnosed patients and refractory patients and between complete remission patients and refractory patients. Statistical analysis indicated that there was no correlation between GST-π gene and LRP gene. The expression of GST-π and LRP genes was not significantly different in different white blood cell (WBC) count groups and different clinical typing groups (ALL and ANLL). It is concluded that the mechanism of MDR resulting from GST-π and LRP genes is different, thereby combination detection of GST-π and LRP genes demonstrates a larger role for evaluating prognosis of AL patients, as compared with detection of GST-π or LRP gene alone. The WBC count and leukemia typing have no relationship with expression of GST-π and LRP genes.
Acute Disease ; Adolescent ; Adult ; Case-Control Studies ; Drug Resistance, Multiple ; genetics ; Drug Resistance, Neoplasm ; genetics ; Female ; Glutathione S-Transferase pi ; genetics ; Humans ; Leukemia ; genetics ; Male ; Middle Aged ; Polymerase Chain Reaction ; Vault Ribonucleoprotein Particles ; genetics ; Young Adult

BACKGROUNDMultidrug resistance is associated with a poor prognosis in various human cancers. However, the clinical significance of the expression of multidrug resistance-related markers in neuroblastoma is still on debate. In this study, the effect of the expression of p-glycoprotein (P-gp), multidrug resistance-associated protein (MRP), and lung resistance protein (LRP) in neuroblastoma was evaluated.

METHODSThe streptavidin-biotin immunoperoxidase (SP) technique was used to evaluate the expression of P-gp, MRP, and LRP in 70 cases of untreated primary neuroblastoma.

RESULTSThe frequencies of the expression of P-gp, MRP, and LRP were 61.4%, 38.6%, and 24.3%, respectively. A significant positive correlation was observed between P-gp and MRP expression (P=0.001), as well as between LRP and MRP expression (P=0.01). The rates of expression of P-gp and MRP were higher in tumors from patients aged greater than one year old than in tumors from patients aged less than 1 year old at time of diagnosis (P=0.01 and 0.018, respectively). MRP expression in tumors that had metastasized was significantly more frequent than in tumors that had not metastasized (P=0.015). The expression of all tested proteins showed a significant relationship with whether or not the tumor had differentiated (P=0.006, 0.000 or 0.001, respectively). MRP expression was significantly associated with a reduction in both median survival time and 2-year cumulative survival (P=0.02). By contrast, P-gp and MRP expression did not correlate with survival. According to Cox regression analysis, only the co-expression of P-gp and MRP had significant prognostic value (relative hazard, 3.513, P=0.033).

CONCLUSIONSThe intrinsic, multidrug resistance of neuroblastoma involves the combined effects of P-gp, MRP, and LRP. MRP expression may be an important factor determining prognosis in neuroblastoma.

ATP-Binding Cassette, Sub-Family B, Member 1 ; analysis ; Adolescent ; Child ; Child, Preschool ; Drug Resistance, Neoplasm ; Female ; Humans ; Immunohistochemistry ; Infant ; Male ; Multidrug Resistance-Associated Proteins ; analysis ; Neoplasm Proteins ; analysis ; Neuroblastoma ; chemistry ; drug therapy ; pathology ; Prognosis ; Vault Ribonucleoprotein Particles

A key issue in the treatment of acute leukemia is the development of resistance to chemotherapeutic drugs. Several mechanisms may account for this phenomenon, including failure of the cell to undergo apoptosis in response to chemotherapy, or failure of the drug to reach and/or affect its intracellular target. This review focuses on the latter mechanisms, and on intracellular drug transport resistance mechanisms in particular. Expression of the ATP-binding cassette (ABC) transporter P-glycoprotein (P-gp) has generally been reported to correlate with prognosis in acute myeloid leukemia (AML). Additionally, of more controversial, expression of the ABC transporter multidrug resistance protein (MRP) and the vault-transporter lung resistance protein (LRP) have been correlated with the outcome in AML.
ATP Binding Cassette Transporter, Sub-Family B ; physiology ; ATP-Binding Cassette, Sub-Family B, Member 1 ; physiology ; Drug Resistance, Multiple ; genetics ; Humans ; Leukemia, Myeloid, Acute ; drug therapy ; genetics ; Neoplasm Proteins ; physiology ; Vault Ribonucleoprotein Particles ; physiology

OBJECTIVE: To explore the relationship among intracellular glutathione S-transferase activity (GST), the expression of lung resistance-related proteins (LRP) in acute leukemia, and its clinical effects. METHODS: The GST activity of bone marrow mononuclear cells and LRP expression in 57 acute leukemia patients were detected by the spectrophotometry assay and immuno-cytochemistry (SABC), respectively. RESULTS: The GST activity of bone marrow mononuclear cells in the acute leukemia group was significantly higher than that of the control group (P < 0.01). The GST activity of mononuclear cells in acute leukemia was positively correlated with the percentage of blast in the bone marrow (r = 0.30, P < 0.05). The GST activity of mononuclear cells in the untreated acute leukemia group was obviously higher than that of the complete remission group (P <0.01). The GST activity in the refractory or relapsed acute leukemia group was significantly higher than that of the complete remission group and untreated leukemia group (P <0.05). In post-chemotherapy 13 of 17 the LRP-positive patients were the non-remission, 12 of the 20 LRP-negative patients were the complete remission. The curative rate of the LRP-positive group was the significantly lower than the LRP-negative group (P < 0.05). The GST activities of non-remission patients in the LRP-positive and LRP-negative group obviously increased. CONCLUSION The increase of GST activity in the bone marrow mononuclear cells is related to the clinical curative effects and the proliferation of blast in acute leukemia. Detection of LRP and GST activities in acute leukemia may have a reference value in judging the leukemia with drug resistance and estimating the prognosis.
Adolescent ; Adult ; Aged ; Bone Marrow Cells ; metabolism ; Child ; Female ; Glutathione Transferase ; metabolism ; Humans ; Leukemia, Myeloid, Acute ; metabolism ; Male ; Middle Aged ; Multidrug Resistance-Associated Proteins ; metabolism ; Neoplasm Proteins ; biosynthesis ; Precursor Cell Lymphoblastic Leukemia-Lymphoma ; metabolism ; Vault Ribonucleoprotein Particles ; biosynthesis

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 observe the effect of tetrandrine on the P170 production expressed by multi-drug resistance gene, lung resistant protein (LRP), and topoisomeras II and elucidate the underlying molecular mechanism.

METHODCellular model of multi-drug resistance was established in S180 tumor cell by means of the scheme of PFC chemotherapy at the dosage lower than that with curative effect. P170, LRP and TOPO II were measured by flow cytometry after the mouse model was treated with tetrandrine for 4 weeks.

RESULTtetrandrine obviously reduced the enhancement of express of P170, LRP and the activity of TOPO II in the tumor cells with multi-drug resistance induced by chemotherapy.

CONCLUSIONTetrandrine significantly inhibits the multi-drug resistance of tumor cells induced by chemotherapy via diminishing both the expression of multi-drug resistance gene and the activity of topoisomeras II.

ATP-Binding Cassette, Sub-Family B, Member 1 ; metabolism ; Alkaloids ; pharmacology ; Animals ; Benzylisoquinolines ; pharmacology ; DNA Topoisomerases, Type II ; metabolism ; Drug Resistance, Multiple ; Drug Resistance, Neoplasm ; Drugs, Chinese Herbal ; pharmacology ; Gene Expression Regulation, Neoplastic ; Genes, MDR ; Mice ; Random Allocation ; Sarcoma 180 ; enzymology ; metabolism ; pathology ; Vault Ribonucleoprotein Particles ; metabolism