Vlaming Maria L H, Pala Zeliha, van Esch Anita, Wagenaar Els, van Tellingen Olaf, de Waart Dirk R, Oude Elferink Ronald P J, van de Wetering Koen, Schinkel Alfred H
Divisions of Experimental Therapy, The Netherlands Cancer Institute, Amsterdam, The Netherlands.
Clin Cancer Res. 2008 Dec 15;14(24):8152-60. doi: 10.1158/1078-0432.CCR-08-1609.
ATP-binding cassette sub-family C member 2 [ABCC2; multidrug resistance-associated protein 2 (MRP2)] and ABCC3 (MRP3) mediate the elimination of toxic compounds, such as drugs and carcinogens, and have a large overlap in substrate specificity. We investigated the roles of Abcc2 and Abcc3 in the elimination of the anticancer drug methotrexate (MTX) and its toxic metabolite 7-hydroxymethotrexate (7OH-MTX) in vivo.
Abcc2;Abcc3(-/-) mice were generated, characterized, and used to investigate possibly overlapping or complementary roles of Abcc2 and Abcc3 in the elimination of MTX and 7OH-MTX after i.v. administration of 50 mg/kg MTX.
Abcc2;Abcc3(-/-) mice were viable and fertile. In Abcc2(-/-) mice, the plasma area under the curve (AUCi.v.) for MTX was 2.0-fold increased compared with wild type, leading to 1.6-fold increased urinary excretion, which was not seen in Abcc2;Abcc3(-/-) mice. Biliary excretion of MTX was 3.7-fold reduced in Abcc2(-/-) but unchanged in Abcc2;Abcc3(-/-) mice. The plasma AUCi.v.s of 7OH-MTX were 6.0-fold and 4.3-fold increased in Abcc2(-/-) and Abcc2;Abcc3(-/-) mice, respectively, leading to increased urinary excretion. The biliary excretion of 7OH-MTX was 5.8-fold reduced in Abcc2(-/-) but unchanged in Abcc2;Abcc3(-/-) mice. 7OH-MTX accumulated substantially in the liver of Abcc2(-/-) and especially Abcc2;Abcc3(-/-) mice.
Abcc2 is important for (biliary) excretion of MTX and its toxic metabolite 7OH-MTX. When Abcc2 is absent, Abcc3 transports MTX and 7OH-MTX back from the liver into the circulation, leading to increased plasma levels and urinary excretion. Variation in ABCC2 and/or ABCC3 activity may therefore have profound effects on the elimination and severity of toxicity of MTX and 7OH-MTX after MTX treatment of patients.
ATP结合盒亚家族C成员2[ABCC2；多药耐药相关蛋白2（MRP2）]和ABCC3（MRP3）介导药物和致癌物等有毒化合物的清除，且在底物特异性方面有很大重叠。我们研究了Abcc2和Abcc3在体内清除抗癌药物甲氨蝶呤（MTX）及其有毒代谢物7-羟基甲氨蝶呤（7OH-MTX）中的作用。
构建、鉴定Abcc2;Abcc3(-/-)小鼠，并用于研究静脉注射50mg/kg MTX后Abcc2和Abcc3在清除MTX和7OH-MTX中可能存在的重叠或互补作用。
Abcc2;Abcc3(-/-)小鼠存活且可育。在Abcc2(-/-)小鼠中，MTX的静脉注射血浆曲线下面积（AUCi.v.）相比野生型增加了2.0倍，导致尿排泄增加了1.6倍，而在Abcc2;Abcc3(-/-)小鼠中未观察到这种情况。Abcc2(-/-)小鼠中MTX的胆汁排泄减少了3.7倍，但在Abcc2;Abcc3(-/-)小鼠中未改变。在Abcc2(-/-)和Abcc2;Abcc3(-/-)小鼠中，7OH-MTX的静脉注射血浆AUCi.v.s分别增加了6.0倍和4.3倍，导致尿排泄增加。Abcc2(-/-)小鼠中7OH-MTX的胆汁排泄减少了5.8倍，但在Abcc2;Abcc3(-/-)小鼠中未改变。7OH-MTX在Abcc2(-/-)尤其是Abcc2;Abcc3(-/-)小鼠的肝脏中大量蓄积。
Abcc2对MTX及其有毒代谢物7OH-MTX的（胆汁）排泄很重要。当缺乏Abcc2时，Abcc3将MTX和7OH-MTX从肝脏转运回循环系统，导致血浆水平和尿排泄增加。因此，ABCC2和/或ABCC3活性的变化可能对MTX治疗患者后MTX和7OH-MTX的清除及毒性严重程度产生深远影响。
