Concomitance of P-gp/LRP Expression with EGFR Mutations in Exons 19 and 21 in Non-Small Cell Lung Cancers

PURPOSE: Traditional chemotherapy is the main adjuvant therapy for the treatment of non-small cell lung cancer (NSCLC). However, the emergence of multi-drug resistance (MDR) has greatly restricted the curative effect of chemotherapy. Therefore, it is necessary to find a method to treat MDR NSCLC clinically. It is worth investigating whether NSCLCs that are resistant to traditional chemotherapy can be effectively treated with tyrosine kinase inhibitors targeting epidermal growth factor receptor (EGFR). MATERIALS AND METHODS: The expression of P-glycoprotein (P-gp) and lung resistance-related protein (LRP) was detected by immunohistochemistry, and mutations in EGFR (exons 19 and 21) and Kirsten rat sarcoma viral oncogene homolog (KRAS) (exon 2) were detected by high-resolution melting analysis (HRMA) of surgical NSCLC specimens from 127 patients who did not undergo traditional chemotherapy or radiotherapy. A Pearson chi-square test was performed to analyze the correlations between the expression of P-gp and LRP and mutations in EGFR and KRAS. RESULTS: The expression frequencies of P-gp and LRP were significantly higher in adenocarcinomas from non-smoking patients; the expression frequency of LRP was significantly higher in cancer tissue from female patients. The frequency of EGFR mutations was significantly higher in well to moderately differentiated adenocarcinomas from non-smoking female patients. The frequency of EGFR mutations in the cancers that expressed P-gp, LRP, or both P-gp and LRP was significantly higher than that in cancers that did not express P-gp or LRP. CONCLUSION: NSCLCs expressing P-gp/LRP bear the EGFR mutation in exon 19 or 21 easily.

Effects of cyclooxygenase-2 selective inhibitor celecoxib on the expression of major vault protein in rats with status epilepticus / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To 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.</p><p><b>METHODS</b>Sixty 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.</p><p><b>RESULTS</b>The 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).</p><p><b>CONCLUSIONS</b>Celecoxib 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.</p>

2,3,7,8-Tetrachlorodibenzo-P-Dioxin Induced Cell-Specific Drug Transporters With Acquired Cisplatin Resistance in Cisplatin Sensitive Cancer Cells

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.

2,3,7,8-Tetrachlorodibenzo-P-Dioxin Induced Cell-Specific Drug Transporters With Acquired Cisplatin Resistance in Cisplatin Sensitive Cancer Cells

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.

RQ-PCR detection of GST-π and LRP genes in adult acute leukemia and its clinical significance / 中国实验血液学杂志

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.

Inhibition of survivin expression and mechanisms of reversing drug-resistance of human lung adenocarcinoma cells by siRNA / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Survivin, a member of the inhibitor of apoptosis protein (IAP) family, overexpresses in tumor cells and not expresses in terminally differentiated adult tissues. This study aimed to investigate the effects of survivin-specific siRNA on cell proliferation, apoptosis and chemosensitivity to cisplatin in vitro and in vivo and explore the mechanisms about decreasing expression of survivin in reversing cancer cells resistance to chemotherapeutic drug.</p><p><b>METHODS</b>Survivin-specific siRNA was transfected into A549/DDP cells. The expression of survivin and lung resistance-related protein (LRP) mRNA levels were determined by RT-PCR, chemosensitivity of A549/DDP (cisplatin) cells to cisplatin was determined by MTT assay, and apoptosis and cell cycle were determined by flow cytometry (FCM). The protein expression levels of survivin, LRP, cyclin-D(1), caspase-3 and bcl-2 were determined by Western blotting analyses. The effect of survivin siRNA inhibition on tumor growth was studied in athymic nude mice in vivo.</p><p><b>RESULTS</b>Survivin-specific siRNA efficiently down-regulated survivin expression. The cell cycle was arrested at G2/M phase, and apoptosis was obviously found. Inhibition of survivin expression could make the IC50 and drug-resistant index of cisplatin decrease, and enhance the cancer cells sensitivity to cisplatin. After transfection by survivin-specific siRNA, expression of LRP and cyclin-D1 were downregulated, caspase-3 expression was upregulated, bcl-2 expression had no obvious change. The animal experiment confirmed knockdown of survivin could inhibit the tumor growth.</p><p><b>CONCLUSIONS</b>Survivin-specific siRNA can efficiently suppress the expression of survivin, increase apoptosis, inhibit cells proliferation and enhance the chemosensitivity to cisplatin in vitro and in vivo. Suppression of survivin expression helping to reverse drug-resistance may have relationship with downregulation of LRP and upregulation of caspase-3. Anti-tumor strategies based on the inhibition of survivin may be useful in targeting lung adenocarcinomas.</p>

Down-regulation of lung resistance related protein by RNA interference targeting survivin induces the reversal of chemoresistances in hepatocellular carcinoma / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Both 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.</p><p><b>METHODS</b>The 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.</p><p><b>RESULTS</b>The 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).</p><p><b>CONCLUSIONS</b>Down 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.</p>

Association of EGFR expression with angiogenesis and chemoresistance in ovarian carcinoma / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To clarify the association of EGFR expression with angiogenesis and chemoresistance in ovarian cancer.</p><p><b>METHODS</b>Immunohistochemical PV-6000 staining was used to detect the expression of EGFR, LRP protein and MVD in 102 ovarian tumor specimens.</p><p><b>RESULTS</b>EGFR, LRP positive rates and MVD in borderline and malignant ovarian specimens were significantly higher than those in the normal and benign ones (P < 0.01). EGFR positive expression rate in stage III-IV carcinoma tissues, poor differentiation and with ascites was higher than that in stage I-II carcinomas of well differentiation and without ascites (P < 0.05). MVD was related to histological grade, residual tumor and ascites, LRP positive expression had no correlation with the clinicopathologic parameters (P > 0.05). The effective rate of chemotherapy in patients with EGFR and LRP-positive expression were 57.1% and 53.7%, respectively, significantly lower than that in cases with EGFR and LRP-negative expression (85.0% and 90.9%, P < 0.05). In the 64 cases with complete data, the three-year survival rate was 53.0%. The survival time was shorter in the cases with EGFR and LRP-positive expression, poor differentiation, ascites and chemoresistance (P < 0.01), and only LRP-positive expression and chemotherapeutic effect were independently related to survival time (P < 0.05). There was a correlation between EGFR and MVD (r = 0.548, P < 0.01), EGFR and LRP positive expression (P = 0.020).</p><p><b>CONCLUSION</b>The expression of EGFR in ovarian cancer is related to angiogenesis and chemoresistance. EGFR and LRP-positive expression are related to chemoresistance, and detection of the two proteins may be helpful in guiding chemotherapy choice for ovarian cancer. LRP-positive expression and chemotherapeutic effect may be independent prognostic factors.</p>

Expression and significance of P-gp/mdr1 mRNA, MRP and LRP in non-Hodgkin's lymphoma / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To 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.</p><p><b>METHODS</b>mdr1 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.</p><p><b>RESULTS</b>(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).</p><p><b>CONCLUSION</b>The 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.</p>

Pharmacological effects of serum containing chinese medicine Bushen Huayu Jiedu Compound Recipe in lung cancer drug-resistance cells / 中国结合医学杂志

<p><b>OBJECTIVE</b>To explore the pharmacologic effects of Chinese medicine Bushen Huayu Jiedu Compound Recipe (BSHYJDR) in drug-resistance cells of lung cancer.</p><p><b>METHODS</b>Human 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.</p><p><b>RESULTS</b>Compared 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).</p><p><b>CONCLUSION</b>It 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.</p>

Effect on mouse S180 MDR tumour cell expression correlated factorial matter by 70% ethanol with Huanglian Jiedu Tang / 中国中药杂志

<p><b>OBJECTIVE</b>To observe the effect on P170, LRP, TOPO II of S180 tumour MDR mice for matter by 70% ethanol with Huanglian Jiedu Tang, and then discuss the molecular biology base for clinic.</p><p><b>METHOD</b>18-22 gramme mice were divided into four groups for normal S180 tumour cell group, matter by 70% ethanol with Huanglian Jiede Tang 100 mg x kg(-1) and 50 mg x kg(-1) in random. Each mouse was given S180 cell 0.2 mL by celiac, and after 24 hours give cisplatin for Injective 3 mg x kg(-1), ip, once a week. And give cyclophosphamide and 5-FU 3 mg x kg(-1), ig, once every day. After 15 days, collect lively mice ascites and give it for onefold normal mice. And then repeat before process. At the same time, every group was given corresponding medicine for 0.2 mL x 10 g(-1). The normal group and the model group were given the same cubage water, all together fore weeks. At last observd the P170, LRP, TOPO II by flow cytometry.</p><p><b>RESULT</b>Matter by 70% ethanol with Huanglian Jiedu Tang could obviously reduce the express of P170 and LRP, and the activiation of TOPO II.</p><p><b>CONCLUSION</b>Matter by 70% ethanol with Huanglian Jiedu Tang can intervene the ocurrence of the multi-drug resistance of tumour cells by regulating the biology gene.</p>

Expressions of LRP, GST-pi and MRP1 in acute leukemia patients and its clinical significance / 中国实验血液学杂志

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.

Prognostic Significance of Multidrug Resistance Gene 1 (MDR1), Multidrug Resistance-related Protein (MRP) and Lung Resistance Protein (LRP) mRNA Expression in Acute Leukemia

The prognostic significance of multidrug resistance (MDR) gene expression is controversial. We investigated whether multidrug resistance gene 1 (MDR1), multidrug resistance-related protein (MRP) and lung resistance protein (LRP) mRNA expression are associated with outcomes in acute leukemia patients. At diagnosis we examined MDR1, MRP and LRP mRNA expression in bone marrow samples from 71 acute leukemia patients (39 myeloid, 32 lymphoblastic) using nested RT-PCR. The expression of each of these genes was then expressed as a ratio in relation to beta-actin gene expression, and the three genes were categorized as being either 0, 1+, 2+ or 3+. MDR1, MRP and LRP mRNA expression was detected in 23.9%, 83.1% and 45.1 %, respectively. LRP mRNA expression was significantly associated with resistance to induction chemotherapy in acute leukemia patients, and in the AML proportion (p=0.02 and p=0.03, respectively). MRP and high MDR1 mRNA expression was associated with poorer 2-yr survival (p=0.049 and p=0.04, respectively). Patients expressing both MRP and LRP mRNA had poorer outcomes and had worse 2-yr survival. The present data suggest that MDR expression affects complete remission and survival rates in acute leukemia patients. Thus, determination of MDR gene expression at diagnosis appears likely to provide useful prognostic information for acute leukemia patients.

Specific inhibition of gene expression of lung resistance-related protein by short interfering RNA / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate inhibitory effect of short interfering RNA (siRNA) on the expression of lung resistance-related protein (LRP) in leukemia cells.</p><p><b>METHODS</b>The 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.</p><p><b>RESULTS</b>Compared 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.</p><p><b>CONCLUSIONS</b>The 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.</p>

Expression of lung resistance-related protein gene in transitional cell carcinoma of the bladder / 中华外科杂志

<p><b>OBJECTIVE</b>To 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.</p><p><b>METHODS</b>66 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.</p><p><b>RESULTS</b>LRP 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).</p><p><b>CONCLUSIONS</b>The 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.</p>

Synergistic effect of bromocriptine combining tumor necrosis factor-alpha on reversing multidrug resistance in a nude mouse model of liver neoplasm / 中华外科杂志

<p><b>OBJECTIVE</b>To 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.</p><p><b>METHODS</b>Human 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.</p><p><b>RESULTS</b>The 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.</p><p><b>CONCLUSIONS</b>TNF-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.</p>

Relationship between expression of multidrug-resistant genes in nasopharyngeal carcinoma tissue and sensitivity to chemotherapy / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>To study the relationship between multidrug-resistant (MDR) expression in nasopharyngeal carcinoma (NPC) and its sensitivity to chemotherapy.</p><p><b>METHODS</b>The specimens of 23 NPC cases were studied by immunohistochemistry with monoclonal antibody of P-glycoprotein (P-gp), multidrug resistance relation protein (MRP), lung-resistance related protein (LRP), topoisomerase II (Topo II), thymidylate synthase (TS), glutathione-S-transferase (GST-pi). Among them, 20 specimens were taken from primary NPC lesion which were treated with two course of cisplatin (DDP) and 5-fluorouracil (5-FU), 3 specimens were taken from cervical lymph-node of recurrent NPC patients who were treated by radical dissection.</p><p><b>RESULTS</b>Various MDR parameters were expressed differently in 22 cases except for 1 clear cell carcinoma case. The difference was statistically significant (P < 0.05). However, there were no significant difference of MDR expression either among various carcinoma pathomorphology cell groups or among different clinical stage groups. Expression of LRP and TS were found in 10 and 14 cases respectively and the chemotherapy responders rates were 20% (2/10) and 28.5% (4/14) respectively. While the chemotherapy responders rates were 70% (7/10) and 5/6 in cases without expression. There was significant difference (P < 0.001, and P < 0.05).</p><p><b>CONCLUSION</b>The NPC patients with LRP and TS expression may be less sensitive to chemotherapy with DDP + 5-FU.</p>

The interference in correlated molecular mechanism obtained multi-drug resistance of mouse S180's tumour cell for different alkaloid / 中国中药杂志

<p><b>OBJECTIVE</b>To observe the base of the interference in correlated biotic active matter obtained multi-drug resistance induced by chemotherapy for different alkaloid, and to supervise the use in clinic to restrain the multi-drug resistant of chemotherapy, and thereby to improve the curative effect.</p><p><b>METHOD</b>After bestowing subter-dosage unite chemotherapeutant to ascites S180 mouse to set up the mouse models of multi-drug resistance of S180 tumour cell, and giving the mouse matrine, terandrine, oxymatrine and berberine hydrooh loride for 4 weeks, the P170, LRP, TOPOII, Fas and apoposis were determined by flow cytometry.</p><p><b>RESULT</b>Matrine and terandrine could obviously reduce the express of P170, LRP and the activation of TOPOII, and increase the ratio of the express of Fas and the apoposis of drug resistant tumour cell. And at the same time it could obviously reduce the express of intercellular adhesion molecule(CD54).</p><p><b>CONCLUSION</b>Matrine and terandrine can interfere in MDR which results from chemotherapeutics by the adjustment of correlated biotic active matter, besides, the different degree of alkaloid effect with different configuration.</p>

Hypoxia-inducible factor-1 alpha dependent expression and significance of the related multidrug resistance genes induced by hypoxia in human hepatocarcinoma cell / 中华外科杂志

<p><b>OBJECTIVE</b>To explore the mechanism of multidrug resistance of hepatocellular carcinoma induced by hypoxia and the potential role of hypoxia-inducible factor-1 alpha (HIF-1 alpha) and multidrug resistance related genes.</p><p><b>METHODS</b>Human hepatocarcinoma cell lines HepG2 cells were exposed to hypoxia and were transfected by plasmid HIF-1 alpha/PCDNA3, respectively. The expressions of multidrug resistance gene (mdr1), multidrug resistance protein (MRP1), and lung resistance protein (LRP) gene at the mRNA and the protein levels in the above two groups were respectively analyzed by real-time fluorescent quantitative PCR and Western-blot technique.</p><p><b>RESULTS</b>In the hypoxia group, the expressions of mdr1, MRP1 and LRP were stepped up correlating to the degree of hypoxia, especially the prominent increase in the expression of MRP1. Furthermore, they were synchronous with the changes of the expression of HIF-1 alpha. Also the increased expression of mdr1, MRP1, and LRP gene was observed in transfected HepG2 cells by plasmid HIF-1 alpha/PCDNA3.</p><p><b>CONCLUSIONS</b>Resistance of hepatocellular carcinoma to chemotherapeutics could be induced by hypoxia. HIF-1 alpha may be critical to the upregulation of the expression of the related multidrug resistance genes induced by hypoxia. HIF-1 alpha and these related multidrug resistance genes could be potential molecular targets for reversing multidrug resistance of hepatocellular carcinoma.</p>

Detection of glutathione S-transferase and lung resistance-related proteins in acute leukemia and its clinical significance / 中南大学学报(医学版)

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.