载有柔红霉素的磁性纳米Fe_3O_4提高裸鼠异种移植模型中多药耐药K562白血病细胞对化疗效果(英文)

Daunorubicin-loaded Magnetic Nanoparticles of Fe_3O_4 Greatly Enhance the Responses of Multidrug-resistant K562 Leukemic Cells in a Nude Mouse Xenograft Model to Chemotherapy

肿瘤的多药耐药是肿瘤化疗失败的主要原因,由于载有柔红霉素的磁性纳米Fe3O4颗粒在体外显示了良好的耐药逆转效果,本实验研究了载有柔红霉素的磁性纳米Fe3O4颗粒在体内对白血病多药耐药逆转效果。将裸鼠高成瘤性白血病细胞株K562-n及其相应的多药耐药株K562-n/VCR分别接种于裸鼠的两侧腹股沟皮下,以建立人类白血病移植瘤模型;将双侧成瘤裸鼠随机分为5组,A组给予生理盐水,B组给予磁性纳米Fe3O4颗粒,C组给予柔红霉素,D组给予载有柔红霉素的磁性纳米Fe3O4颗粒,E组给予载有柔红霉素的磁性纳米Fe3O4颗粒同时在肿瘤表面建立固定磁场。在实验开始后的第1,5,9,13,17,21天分别测量肿瘤体积。实验结束后,分离瘤组织并用RT-PCR,Westernblot检测mdr-1的转录和表达。结果表明:D组、E组的K562-n/VCR肿瘤体积显著小于A、B、C3个组(D或E组相对于A,B或C组p<0.05)。病理检查显示:A组、B组肿瘤细胞生长良好,未见明显细胞坏死;C组肿瘤细胞有散在细胞坏死,部分细胞出现核固缩、核碎裂等;D、E组肿瘤组织内可见细胞明显破碎、坏死、组织的纤维化。D和E组的mdr-1的转录水平明显低于A、B、C3个组,但是P-gp的表达在5个组中无差异。C组、D组、E组3个组K562-n肿瘤平均肿瘤体积显著小于的A、B两组的平均肿瘤体积(C、D或E组相对于A或B组p<0.05)。A组、B组肿瘤细胞生长良好,未见明显细胞坏死;在C、D、E组肿瘤组织内可见细胞明显破碎、坏死、组织的纤维化。结论:载有柔红霉素的磁性纳米Fe3O4颗粒在体内具有明显的逆转多药耐药的作用,但是相对于单用柔红霉素,载有柔红霉素的磁性纳米Fe3O4颗粒在敏感的K562-n的肿瘤中并不能进一步提高疗效;本实验中外加磁场并未增加疗效。

Multidrug resistance （MDR） plays a major role in the failure of cancer chemotherapy. Since Fe3O4-magnetic nanoparticle loaded with daunorubicin（DNR） can overcome multidrug-resistance of K562 cells in vitro, the effect of Fe3O4-magnetic nanoparticle loaded with DNR on multidrug-resistant K562 cells was studied in vivo, the K562-n and its MDR counterpart K562-n/VCR cells were inoculated subcutaneously into both sides of the back of nude mice to estab- lish a human leukemia xenograft model. The mice were randomly divided into group A receiving normal saline, group B receiving DNR, group C receiving Fe3O4-magnetic nanoparticle, group D receiving Fe3 O4-magnetic nanoparticle loaded with DNR and group E receiving Fe3 04-magnetic nanoparticle containing DNR with a magnetic field built on the surface of the tumor tissue. The tumor volume was measured on the day 1, 5, 9, 13, 17 and 21 after the first treatment. Tumor tissues were isolated for examination of the expression of mdr-1 by reverse transcription polymerase chain reaction and Western blotting. The results showed that for K562-n/VCR tumor, the tumor volume was markedly lower in groups D and E than that in groups A, B and C. Pathological observation revealed that the tumor cells of group A and B grew well, some disseminated necrosis and some cells with karyorrhexis and karyopycnosis existed in group C. However, significant fracture, necrosis of cell and subsequently fibrosis were seen in group D and E. The transcription of mdr-1 gene in groups D and E was significantly lower than that in groups A, B and C （ group D and E vs group A, B or C, p 〈 0. 05 ）. However, there were no differences about the protein expression of P-gp between these groups. The tumor volume of K562-n in groups C, D and E was markedly lower than that in groups A and B （group C, D and E vs group A or B, p 〈 0.05 ）. Pathological observation showed that the tumor cell of group A and B grew well, and no obvious necrosis was observed. Significant fracture, necrosis of cell and subsequently fibrosis were seen in group C, D and E. It is coneluded that DNR-loaded Fe3O4 magnetic nanopartieles can suppress the growth of the MDR K562-n/VCR tumor in vivo, but can not further enhance its efficacy on the sensitive K562-n tumor as compared to DNR alone. The additional external magnetic field failed to further improve the antitumor effect in vivo.