Copper-transporting P-Type Adenosine Triphosphatase (ATP7B) Is Expressed in Human Breast Carcinoma

This is the first report to show that a copper-transporting P-type adenosine triphosphatase, ATP7B, is expressed in certain breast carcinomas, and a priori knowledge of its expression is important for the choice of therapy. We investigated the hypothesis that ATP7B, which was shown to be associated with cisplatin resistance in vitro , is expressed in certain breast carcinomas. To test this hypothesis, ATP7B expression and protein level were examined in 41 breast carcinomas using RT-PCR and immunohistochemistry. ATP7B gene/protein could be detected in 22.0% (9/41) of breast carcinomas and ATP7B gene expression was correlated well with the protein expression. In nine ATP7B-positive tumors, adjacent normal breast tissue was similarly analyzed, revealing that ATP7B is upregulated in breast carcinoma. ATP7B gene expression in poorly differentiated carcinoma was significantly higher than that in well-/moderately differentiated carcinoma ( P =0.012). Furthermore, we found no association between the ATP7B gene/protein expression and that of MDR1, MRP1, LRP and BCRP. These findings suggested that ATP7B gene expression might be a chemoresistance marker for cisplatin in patients with poorly differentiated breast carcinoma.     

Copper-transporting P-type adenosine triphosphatase (ATP7B) is expressed in human breast carcinoma.

This is the first report to show that a copper-transporting P-type adenosine triphosphatase, ATP7B, is expressed in certain breast carcinomas, and a priori knowledge of its expression is important for the choice of therapy. We investigated the hypothesis that ATP7B, which was shown to be associated with cisplatin resistance in vitro, is expressed in certain breast carcinomas. To test this hypothesis, ATP7B expression and protein level were examined in 41 breast carcinomas using RT-PCR and immunohistochemistry. ATP7B gene / protein could be detected in 22.0% (9 / 41) of breast carcinomas and ATP7B gene expression was correlated well with the protein expression. In nine ATP7B-positive tumors, adjacent normal breast tissue was similarly analyzed, revealing that ATP7B is upregulated in breast carcinoma. ATP7B gene expression in poorly differentiated carcinoma was significantly higher than that in well- / moderately differentiated carcinoma (P = 0.012). Furthermore, we found no association between the ATP7B gene / protein expression and that of MDR1, MRP1, LRP and BCRP. These findings suggested that ATP7B gene expression might be a chemoresistance marker for cisplatin in patients with poorly differentiated breast carcinoma.     

LRP,MRP,MDR1基因在非小细胞肺癌中的表达及其临床意义

目的 探讨肺耐药蛋白（ｌｕｎｇ ｒｅｓｉｓｔａｎｃｅ ｐｒｏｔｅｉｎ,ＬＲＰ）,多药耐药蛋白（ｍｕｌｔｉｄｒｕｇ ｒｅｓｉｓｔａｎｃｅａｓｓｏｃｉａｔｅｄ ｐｒｏｔｅｉｎ,ＭＲＰ）,和多药耐药基因（ｍｕｌｔｉｄｒｕｇ ｒｅｓｉｓｔａｎｅ,ＭＤＲ１）ｍＲＮＡ在非小细胞肺癌（ｎｏｎ－ｓｍａｌｌ ｃｅｌｌ ｃａｎｃｅｒ,ＮＳＣＬＣ）中的共表达及临床意义。方法 ＲＴ－ＰＣＲ检测ＮＳＣＬＣ冰冻组织中上述耐药     

Expression of LRP Gene in Breast Cancer Patients Correlated with MRP1 as Two Independent Predictive Biomarkers in Breast Cancer

Background: Breast cancer is the most common malignancy in women. Multidrug resistance (MDR) is still a greatobstacle of breast cancer chemotherapy. We have previously shown that multidrug resistance-associated protein 1 (MRP1)is associated with response to neoadjuvant chemotherapy. The lung resistance-related protein (LRP) is identified asa prognostic marker and response to treatment factor which has been studied mainly in hematological malignancy andleukemia. In this study, we aimed to analyze LRP expression and possible correlation between the expression level ofthis gene with MRP1 as a candidate marker for chemotherapy resistance. Materials and Methods: We collected 54breast tumors and adjacent normal tissues from Iranian breast cancer patients and Real time RT-PCR was employed tomeasure the gene expression level in our samples. Results: MRP1 and LRP expression level were significantly lowerin tumor tissues of the patients responding to chemotherapy compared to non-responding patients. No relation betweenthe expression level of either of these genes and clinicopathology markers was found. Conclusion: Our results suggestthat LRP gene expression is correlated to MRP1 in human breast cancer cells and may affect the clinical response totreatment.     

Multiple gene expression analysis reveals distinct differences between G2 and G3 stage breast cancers, and correlations of PKC eta with MDR1, MRP and LRP gene expression.

A possible link between protein kinase C (PKC) and P-glycoprotein (P-gp)-mediated-multidrug resistance (MDR) was assumed from studies on MDR cell lines selected in vitro. The functional relevance of PKC for the MDR phenotype remains unclear, and the involvement of a particular PKC isozyme in clinically occurring drug resistance is not known. Recently, we have demonstrated significant correlations between the expression levels of the PKC eta isozyme and the MDR1 or MRP (multidrug resistance-associated protein) genes in blasts from patients with acute myelogenous leukaemia (AML) and in ascites cell aspirates from ovarian cancer patients. To extend these findings to further types of human tumours we analysed specimens from 64 patients with primary breast cancer for their individual expression levels of several MDR-associated genes (MDR1, MRP, LRP (lung cancer resistance-related protein), topoisomerase (Topo) II alpha/IIbeta, cyclin A and the PKC isozyme genes (alpha, beta1, beta2, eta, theta, and mu) by a cDNA-PCR approach. We found significantly enhanced mean values for MRP, LRP and PKC eta gene expression, but significantly decreased Topo II alpha and cyclin A gene expression levels in G2 tumours compared with G3. Remarkably, significant positive correlations between the MDR1, MRP or LRP gene expression levels and PKC eta were determined: MDR1/PKC eta (rs = +0.6451, P < 0.0001) n = 62; MRP/PKC eta (rs = +0.5454, P < 0.0001) n = 63; LRP/PKC eta (rs = +0.5436, P < 0.0001) n = 62; MRP/LRP (rs = +0.7703, P < 0.0001) and n = 62, MDR1/MRP (rs = +0.5042, P < 0.0001) n = 62. Our findings point to the occurrence of a multifactorial MDR in the clinics and to PKC eta as a possible key regulatory factor for up-regulation of a series of MDR-associated genes in different types of tumours.     

Increased expression of the breast cancer resistance protein (BCRP) in relapsed or refractory acute myeloid leukemia (AML).

Expression of the multidrug resistance proteins P-glycoprotein, encoded by the MDR1 gene, multidrug resistance-associated protein (MRP1) and the lung resistance-related protein or major vault protein (LRP/MVP) is associated with clinical resistance to chemotherapy in acute myeloid leukemia (AML). Recently, the breast cancer-resistant protein (BCRP), the equivalent of mitoxantrone-resistant protein (MXR) or placental ABC transporter (ABCP), was described in AML. We investigated MDR1, MRP1, LRP/MVP and BCRP mRNA expression simultaneously in 20 paired clinical AML samples from diagnosis and relapse or refractory disease, using quantitative Taqman analysis. In addition, standard assays for P-glycoprotein expression and function were performed. BCRP was the only resistance protein that was expressed at a significantly higher RNA level (median 1.7-fold, P = 0.04) at relapsed/refractory state as compared to diagnosis. In contrast, LRP/MVP mRNA expression decreased as disease evolved (P = 0.02), whereas MDR1 and MRP1 mRNA levels were not different at relapse as compared to diagnosis. Also, at the protein level no difference of MDR1 between diagnosis and relapse was found. A significant co-expression of BCRP and MDR1 was found at diagnosis (r = 0.47, P = 0.04). The present results suggest that BCRP, but not MDR1, MRP1 or LRP/MVP is associated with clinical resistant disease in AML.     

耐顺铂相关基因MDR1、MRP、LRP及GST-π在非小细胞肺癌中的表达及与生存相关的Meta分析

目的:采用循证医学系统分析方法了解肿瘤耐顺铂相关基因与非小细胞肺癌的相关性,为科学制定化疗方案提供理论依据.方法:检索中国学术期刊网(CNKI)全文数据库、维普科技期刊、美国国立图书馆PUBMED;检索时间段为1979 - 2011年;获得符合纳入标准的关于非小细胞肺癌耐药相关基因MDR1、MRP、LRP及GST -π的文献研究27篇;采用Stata11.0进行统计分析.结果:非小细胞肺癌组织与正常肺组织耐药基因表达合并效应显示,非小细胞肺癌组织耐顺铂相关基因表达水平明显高于正常肺组织.4种基因合并OR值并计算95％可信区间,各基因表达结果按照OR值大小顺序,OR值及95％可信区间依次为GST -π30.86(16.03,59.40)、LRP 13.96(9.27,21.01)、MRP 12.69(8.36,19.26)、MDR1 8.03 (4.45,14.48),其中LRP及MRP基因3年死亡人数明显高于3年生存人数,OR值及95％可信区间分别为LRP 4.75(2.11,10.67)、MRP 4.61(2.28,9.32).结论:耐顺铂相关基因MRP、LRP、GST -π及MDR1在非小细胞肺癌组织中呈高表达,尤以GST -π基因为著,其余依次是LRP、MRP、MDR1基因.各基因在非小细胞肺癌组织中表达的高低直接影响化疗效果和预后,是非小细胞肺癌化疗耐药中的重要基因.     

贲门癌组织中多药耐药基因和多药耐药相关蛋白基因表达的临床研究

目的了解多药耐药基因（ＭＤＲ１）和多药耐药相关蛋白基因（ＭＲＰ）在贲门癌组织中的表达及其临床意义。方法采用反转录聚合酶链反应（ＲＴ－ＰＣＲ）技术,检测了４６例贲门癌及癌旁组织中ＭＤＲ１和ＭＲＰ６４表达。结果癌组织中ＭＤＲ１和ＭＲＰ表达的阳性率分别６３％和５０％,均高于癌旁组织（Ｐ＜０．０５）;术前化疗的ＭＤＲ１ｍＲＮＡ和ＭＲＰｍＲＮＡ表达水平高于未化疗者（Ｐ＜０．０５）;中低分化肿瘤的ＭＤＲ１ｍＲＮＡ和ＭＲＰｍＲＮＡ表达水平高于高分化肿瘤（Ｐ＜０．０５）;结论贲门癌组织中具有内源和获得性多药耐药性;ＭＤＲ１和ＭＲＰ表达与贲门癌的ＴＮＭ分期无关,其高表达状态可预示肿瘤组织的分化不良。     

Drug resistance-associated markers P-glycoprotein, multidrug resistance-associated protein 1, multidrug resistance-associated protein 2, and lung resistance protein as prognostic factors in ovarian carcinoma.

Intrinsic and/or acquired resistance to chemotherapy is the major obstacle to overcome in the treatment of patients with ovarian carcinoma. The aim of the present study was to investigate the prognostic value of drug resistance-associated proteins P-glycoprotein (P-gp), multidrug resistance-associated protein 1 (MRP1), canalicular multispecific organic anion transporter (c-MOAT/MRP2), and lung resistance protein (LRP) in ovarian carcinoma. Expression of P-gp, MRP1, MRP2, and LRP was determined by immunohistochemistry of frozen tissue sections of 115 ovarian carcinoma patients and related to clinicopathological factors, response to chemotherapy, and progression-free survival. P-gp expression was observed in 20 of 115 (17%), MRP1 in 51 (44%), MRP2 in 19 (16%), and LRP in 85 (74%) tumors. Expression of MRP1 was related to MRP2 (P<0.0001) and P-gp (P<0.001) expression, whereas LRP expression was more frequently observed in patients with early stage (P<0.01), lower grade (P<0.05), and smaller residual tumor (P<0.05). Early stage (P<0.001), smaller residual tumor (P<0.001), and lower differentiation grade (P<0.05) were related to longer (progression-free) survival. P-gp, MRP1, MRP2, and LRP expression were neither related to response to first-line chemotherapy in 59 evaluable patients nor to progression-free survival in all patients. On multivariate analysis, only stage and residual tumor were independent prognostic factors for survival. In conclusion, in ovarian carcinoma, MRP1 expression is associated with MRP2 and P-gp expression, whereas LRP expression is associated with favorable clinicopathological characteristics. Assessment of P-gp, MRP1, MRP2, or LRP does not allow prediction of response to chemotherapy or survival in ovarian carcinoma.     

Effects of neoadjuvant chemotherapy on MDR1 and MRP gene expression in primary breast cancer

Objective: To investigate the effects of neoadjuvant chemotherapy on the expression of drug resistance genes, multidrug resistance-1 (MDR1) and multidrug resistance-associated protein (MRP), in patients with primary breast cancer. Methods: MDR1 and MRP expression were detected by semi-quantitative RT-PCR in 20 patients with primary breast cancer, before and after chemotherapy. Results: Before chemotherapy, MDR1 and MRP expression can be detected in 15 cases (75%) and 18 cases (90%) respectively. After chemotherapy, expression of MDR1 is not significantly different from that before chemotherapy, but expression of MRP is significantly different from that before chemotherapy. Conclusion: Expression of drug resistance gene MRP, but not MDR1, is enhanced in patients with primary breast cancer submitted to neoadjuvant chemotherapy.     

MRP、GST-π、TopoⅡα和LRP在胃癌组织中的表达及意义

背景与目的:多药耐药相关蛋白(multidrugresistance-associatedprotein,MRP)、肺耐药蛋白(lungresistanceprotein,LRP)、谷胱甘肽转移酶(glutathione-S-transferase-π,GST-π)和拓扑异构酶Ⅱα(topoisomeraseⅡα,TopoⅡα)均在多药耐药中发挥重要作用。联合检测它们在胃癌组织中的表达,目前国内外报道极少。本研究旨在探讨联合检测MRP、GST-π、TopoⅡα、LRP在胃癌组织中的表达及意义。方法:应用免疫组化SP法检测MRP、GST-π、TopoⅡα、LRP在90例胃癌标本中的表达,采用χ2检验和Fisher精确检验分析它们表达的意义。结果:(1)MRP、GST-π、TopoⅡα、LRP在胃癌组织中的阳性表达率分别为88.9%、91.1%、74.4%和87.7%,均高于在正常胃粘膜组织中的表达(P<0.05)。(2)MRP、GST-π、LRP在高、中分化腺癌中的表达均高于低分化腺癌,而TopoⅡα在高、中分化腺癌中的表达低于低分化腺癌(P<0.05);此四者的表达情况在不同浸润程度及有/无淋巴结转移的胃癌组织之间均无统计学差异(P>0.05)。(3)MRP、GST-π、TopoⅡα、LRP两两间均无相关性。结论:MRP、GST-π、TopoⅡα和LRP均在胃癌原发性多药耐药中起重要作用,它们在胃癌组织中的表达与肿瘤分化程度有关,而与肿瘤浸润程度及是否有淋巴结转移无关。     

Multidrug resistance genes (MRP) and MDR1 expression in small cell lung cancer xenografts: relationship with response to chemotherapy

Intrinsic or acquired drug resistance is a major limiting factor of the effectiveness of chemotherapy. Increased expression of either the MRP gene or the MDR1 gene has been demonstrated to confer drug resistance in vitro. In this study, we examined MRP and MDR1 gene expression in a panel of 17 small cell lung cancers (SCLC) xenografted into nude mice from treated and untreated patients using an RT-PCR technique. For some of them, the outcome of the corresponding patients was known and we related MDR1/MRP expression with the xenograft response to C′CAV (cyclophosphamide, cisplatin, adriamycin and etoposide) combined chemotherapy. Fifteen (88%) of the 17 cases of SCLC were found to be positive for either MDR1 or MRP. MRP gene expression was present in 12 (71%) of 17 cases, whereas MDR1 gene expression was detected in eight (50%) of 16 cases. For six SCLC, the survival duration of patients differed, with three patients surviving for more than 30 months after therapy. Among these six tumours, five expressed MRP and/or MDR1. These six xenografts responded to the C′CAV treatment but a significant rate of cure was obtained in only three cases. No obvious relationship was observed between the response to this treatment and MRP or MDR1 expression. However, the remarkably high levels and frequency of MRP expression in some SCLC samples indicate that future developments in chemotherapy of this tumour type should anticipate that drugs which are substrates of MRP may be of limited effectiveness.     

肺癌组织中多药耐药基因及相关蛋白表达的研究

目的:探讨P-糖蛋白(P-glycopro-tein,P-gp)、肺癌耐药蛋白(lung cancer resis-tence protein,LRP)和多药耐药相关蛋白(multidrug resistence protein,MRP)在肺癌组织中的表达及其临床意义。方法:应用SP法检测116例术前未做化疗的肺癌组织中P-gp、LRP和MRP的表达水平。结果:P-gp在腺癌组织中的阳性表达率为78.26%(36/46),小细胞癌为63.64%(7/11),鳞状细胞癌为47.46%(28/59);三者相比差异有统计学意义,P=0.018。LRP在腺癌组织中的阳性表达率为89.13%(41/46),鳞状细胞癌为44.07%(26/59),小细胞癌为27.27%(3/11);三者相比差异有统计学意义,P=0.0001;MRP在不同癌组织中的表达差异无统计学意义,P=0.4165。在腺癌、鳞状细胞癌和小细胞癌组织中同时有两种或两种以上耐药基因产物表达阳性率分别为89.13%(41/46)、49.15%(29/59)和27.28%(3/11),三种类型间比较差异有统计学意义,P=0.0001。结论:不同组织学类型的肺癌存在不同程度的耐药性,检测P-gp、LRP和MRP的协同表达对于指导临床化疗方案的实施有重要意义。     

Expression of copper-transporting P-type adenosine triphosphatase (ATP7B) as a chemoresistance marker in human oral squamous cell carcinoma treated with cisplatin

An important clinical problem in the treatment of oral squamous cell carcinoma is the intrinsic/acquired resistance to cisplatin-based chemotherapy. Copper-transporting P-type adenosine triphosphate (ATP7B) has been reported to be associated with cisplatin resistance in vitro (Komatsu et al., Cancer Res 60, 1312-1316,2000). However, the clinical significance of this transporter has not previously been addressed. Our aim of this study was to investigate if ATP7B is expressed in oral squamous cell carcinoma and whether its expression correlates with prognosis and reduced responsiveness to cisplatin treatment. Biopsy tissues were obtained from the tumors of 70 patients with oral SCC, and 51 patients received cisplatin-based preoperative chemotherapy. We performed immunohistochemical analysis of ATP7B using monoclonal antibody against ATP7B in 51 oral SCC and adjacent neoplastic tissues. The significance of ATP7B in the prognosis of patients with oral SCC was also examined in the survival analysis of mortality follow-up data covering the period 1991 through 2000. We retrospectively examined the expression of ATP7B in primary oral SCC carcinoma and its association with chemotherapeutic effect. A variable degree of cytoplasmic staining of tumor cells was observed in 54.9% (28/51 cases) of the analyzed carcinomas. Patients with ATP7B-positive tumors had a significantly inferior response to chemotherapy compared with the patients with ATP7B-negative tumors (P = 0.03). The patients who received cisplatin-based chemotherapy with ATP7B-positive carcinomas had a significantly poorer overall survival than those with ATP7B-negative tumors (P = 0.015). These findings suggest that high levels of ATP7B expression in oral SCC are associated with unfavorable clinical outcome in patients with oral SCCs treated with cisplatin-based chemotherapy. ATP7B expression may be a preoperative indicator for a choice of cisplatin in some patients.     

Impact of BCRP/MXR, MRP1 and MDR1/P-Glycoprotein on thermoresistant variants of atypical and classical multidrug resistant cancer cells

The impact of the ABC transporters breast cancer resistance protein/mitoxantrone resistance associated transporter (BCRP/MXR), multidrug resistance-associated protein 1 (MRP1) and multidrug resistance gene-1/P-glycoprotein (MDR1/PGP) on the multidrug resistance (MDR) phenotype in chemoresistance and thermoresistance was investigated in the parental human gastric carcinoma cell line EPG85-257P, the atypical MDR subline EPG85-257RNOV, the classical MDR subline EPG85-257RDB and their thermoresistant counterparts EPG85-257P-TR, EPG85-257RNOV-TR and EPG85-257RDB-TR. Within the atypical MDR subline EPG85-257RNOV expression of BCRP/MXR and of MRP1 were clearly enhanced (vs. parental and classical MDR lines). MDR1/PGP expression was distinctly elevated in the classical MDR subline EPG85-257RDB (vs. parental and atypical MDR sublines). In all thermoresistant counterparts basal expression of BCRP/MXR, MRP1 and MDR1/PGP was increased relative to thermosensitive sublines. Although it could be shown that the overexpressed ABC transporters were functionally active, however, no decreased drug accumulations of doxorubicin, mitoxantrone and rhodamine 123 were observed. Thus, expression of BCRP/MXR, MRP1 and MDR1/PGP was found to be dependent on the appropriate type of chemoresistance; correlating with a classical or atypical MDR phenotype. Within the thermoresistant variants, however, the increase in ABC transporter expression did obviously not influence the MDR phenotype.