A.N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, Moscow, Russia.
PLoS One. 2011 Mar 3;6(3):e17541. doi: 10.1371/journal.pone.0017541.
Plant biotechnology provides a valuable contribution to global health, in part because it can decrease the cost of pharmaceutical products. Breast cancer can now be successfully treated by a humanized monoclonal antibody (mAb), trastuzumab (Herceptin). A course of treatment, however, is expensive and requires repeated administrations of the mAb. Here we used an Agrobacterium-mediated transient expression system to produce trastuzumab in plant cells.
METHODOLOGY/PRINCIPAL FINDINGS: We describe the cloning and expression of gene constructs in Nicotiana benthamiana plants using intron-optimized Tobacco mosaic virus- and Potato virus X-based vectors encoding, respectively, the heavy and light chains of trastuzumab. Full-size antibodies extracted and purified from plant tissues were tested for functionality and specificity by (i) binding to HER2/neu on the surface of a human mammary gland adenocarcinoma cell line, SK-BR-3, in fluorescence-activated cell sorting assay and (ii) testing the in vitro and in vivo inhibition of HER-2-expressing cancer cell proliferation. We show that plant-made trastuzumab (PMT) bound to the Her2/neu oncoprotein of SK-BR-3 cells and efficiently inhibited SK-BR-3 cell proliferation. Furthermore, mouse intraperitoneal PMT administration retarded the growth of xenografted tumors derived from human ovarian cancer SKOV3 Her2+ cells.
CONCLUSIONS/SIGNIFICANCE: We conclude that PMT is active in suppression of cell proliferation and tumor growth.
植物生物技术为全球健康做出了重要贡献，部分原因是它可以降低药品的成本。乳腺癌现在可以通过一种人源化单克隆抗体（mAb）曲妥珠单抗（赫赛汀）成功治疗。然而，一个疗程的治疗费用昂贵，需要多次重复给予 mAb。在这里，我们使用农杆菌介导的瞬时表达系统在植物细胞中生产曲妥珠单抗。
方法/主要发现：我们描述了基因构建体在本氏烟中的克隆和表达，使用分别编码曲妥珠单抗重链和轻链的内含子优化的烟草花叶病毒和马铃薯病毒 X 为基础的载体。从植物组织中提取和纯化的全长抗体通过（i）在荧光激活细胞分选测定中与 SK-BR-3 人乳腺腺癌细胞系表面的 HER2/neu 结合，和（ii）测试体外和体内对 HER-2 表达的癌细胞增殖的抑制作用，来测试其功能和特异性。我们表明，植物制造的曲妥珠单抗（PMT）与 SK-BR-3 细胞的 Her2/neu 癌蛋白结合，并有效地抑制 SK-BR-3 细胞的增殖。此外，小鼠腹腔内给予 PMT 延迟了源自人卵巢癌 SKOV3 Her2+细胞的异种移植肿瘤的生长。
结论/意义：我们得出结论，PMT 能有效抑制细胞增殖和肿瘤生长。
