三种耐药相关基因及其蛋白在乳腺癌组织中的表达和意义

The expression and significance of MDR1 ,BCRP,LRP mRNA and protein in breast cancer

目的 探讨乳腺癌组织和癌旁正常组织中MDR1、BCRP、LRP的mRNA及其相应蛋白P-gp、BCRP、LRP的阳性表达情况及临床意义.方法 采用RT-PCR检测42份乳腺癌组织及其相应癌旁正常组织中MDR1、BCRP、LRP mRNA的相对表达量,同时采用IHC检测126份乳腺癌组织及42份相应癌旁正常组织中P-gp、BCRP、LRP蛋白的阳性率,并观察3种耐药相关基因及其蛋白与乳腺癌患者临床病理因素、腋窝淋巴结转移及5年复发转移与未复发转移之间的关系.结果 RT-PCR检测MDR1、BCRP、LRP mRNA在乳腺癌组织中的相对表达量分别为0.81±0.17、0.78 ±0.14、0.79±0.13,癌旁正常组织中的相对表达量分别为0.33±0.11、0.45±0.09、0.36±0.10;3种耐药基因在2组中的相对表达量的差异均有统计学意义（t值分别为4.613、4.850、8.089,P均〈0.01）.IHC检测P-gp、BCRP、LRP蛋白在乳腺癌组织中的阳性率分别为41%（52/126）、39%（49/126）和66%（83/126）,癌旁正常组织中的阳性率分别为14%（6/42）、17%（7/42）和19%（8/42）,3种耐药蛋白在2组中的表达差异有统计学意义（x2值分别为10.147、7.020、27.820,P均〈0.01）.MDR1 mRNA和P-gp与乳腺癌患者不同临床分期及腋窝淋巴结有无转移有关（r=0.369、0.39 8,P均〈0.05）,BCRPmRNA及其蛋白与乳腺癌患者腋窝淋巴结有无转移有关（r=0.355,P〈0.05）;5年内发生复发转移的39例患者与5年内未发生复发转移的32例患者P-gp、BCRP及LRP阳性率比较,P-gp阳性率在2组中的差异有统计学意义（x2=11.771,P〈0.01）,BCRP及LRP阳性率在2组中的差异无统计学意义（x2=2.261、0.078,P均〉0.05）.3种耐药基因及其蛋白在乳腺癌组织中阳性表达的一致率分别为90.48%、92.85%和85.71%（Kappa值分别为0.806、0.751和0.697,P均〈0.01）.结论 乳腺癌中存在着广泛的原发性多药耐药现象,3种耐药基因MDR1、BCRP、LRP的mRNA及其P-gp、BCRP、LRP蛋白均参与了乳腺癌多药耐药的形成;检测3种耐药基因和蛋白的表达可为乳腺癌患者有目的 地选择化疗方案提供一定的理论依据及策略;特别是对于P-gp阳性表达者不宜使用CAF（环磷酰胺＋阿霉素＋5-氟尿嘧啶）方案化疗.

Objective To investigate the expression and the significance of the MDR1, breast cancer resistance protein, lung cancer resistance protein mRNA and corresponding proteins P-gp, BCRP and LRP in breast cancer tissues and adjacent breast tissues. Methods RT-PCR was used to exam the expression of MDR1, BCRP, LRP mRNA in 42 breast cancer tissues and 42 adjacent tissues. IHC was used to exam the expression of P-gp, BCRP and LRP in 126 breast cancer tissues and 42 adjacent tissues, and theirs relationships with clinicopathological parameters in breast cancer, axillary lymph node status and 5-year recurrence and metastasis. Results The relative expression levels of MDR1, BCRP and LRP mRNA were 0.81 ±0.17,0.78 ±0.14,0.79 ±0.13 in breast cancer tissues and 0.33 ±0.11,0.45 ±0.09,0.36 ±0.10 in adjacent tissues respectively. There were significant differences between cancer tissues and adjacent tissues （ t = 4.613, 4.850 and 8. 089, P 〈 0.01 ）. The positivities of P-gp, BCRP and LRP were 41% （ 52/126） ,39% （49/126） and 66% （83/126） in breast cancer tissues. There were significant differences between cancer tissues and adjacent tissues （x2 = 10.147, 7.020, 27.820, P 〈 0.01 ）. The expression of MDR1 mRNA/P-gp was significantly associated with tumor stage and lymph node metastasis （ r = 0.369,0.398, P 〈 0.05 ）. The expression of BCRP （mRNA/protein） was significantly associated with lymph node metastasis （r = 0.355, P 〈 0.05 ） . The positivities of P-gp were significantly different between 39 recurrence/metastasis patients occurred in 5 years and 32 unrecurrence/nonmetastasis patients in 5 years （x2 = 11.771, P 〈 0.01 ）. The positivities of BCRP and LRP were not significantly different in these two groups（x2 =2.261,0.078,P 〉0.05）. The coincidence rates for expression of MDR1 ,BCRP,LRP mRNA and their proteins in breast cancer tissues were 90.48% ,92.85% and 85.71% respectively （the Kappa values were 0.806,0.751 and 0.697, P 〈 0.01 ）. Conclusions Multidrug resistance is common in breast cancer. The three drug resistance genes and proteins are involved in the formation of multidrug resistance of breast cancer. Detection of multidrng resistance genes in breast cancer may be useful to choose chemotherapy,especially patients with P-gp positive expression are not advised to use the CAF chemotherapy.