Department of Biological Sciences, University of Massachusetts, Lowell, MA 01854, USA.
Int J Hyperthermia. 2011;27(7):682-97. doi: 10.3109/02656736.2011.609863.
HER-2 is in the EGF tyrosine kinase receptor family, overexpressed by many human cancers and minimally expressed by normal adult tissues. HER-2 expression in human cancers is correlated with reduced survival, increased metastasis, reduced apoptosis and increased proliferation. Herceptin is a humanised mouse antibody that targets and inactivates HER-2. In the present study, Herceptin was used to deliver ferric oxide-enriched nanoparticles to HER-2(+) cancer cells. If exposed to alternating magnetic field (AMF), the nanoparticles heat. We tested the ability of AMF-activated Herceptin-directed nanoparticles to selectively kill HER-2(+) human cancer cells.
Herceptin-conjugated nanoparticles were incubated with normal human mammary epithelial cells (HMEC)(HER-2(-)) or malignant human mammary epithelial cells (SK-BR-3)(HER-2(+)). Cells were stained to detect Herceptin or iron and the kinetics of binding quantified. Once conditions were optimised for binding, cells were exposed to either antibody-directed or non-antibody-conjugated nanoparticles, washed and sham-treated or exposed to AMF and cell death quantified.
SK-BR-3 cells bound Herceptin-directed nanoparticles in increasing amounts over 3 h but did not retain non-antibody conjugated nanoparticles. HMECs did not retain either nanoparticles. SK-BR-3 cells with bound Herceptin-directed-nanoparticles, exposed to AMF, died by apoptosis, quantifiable by Live/Dead and nuclear morphology assays and released LDH. Sham-treated SK-BR-3 cells with Herceptin-directed nanoparticles, HMECs with either nanoparticles, with or without AMF treatment, exhibited no increase in toxicity above baseline cell death using these three assays.
These studies demonstrate Herceptin-directed nanoparticles can selectively kill HER-2(+) cancer cells via hyperthermia after AMF activation.
HER-2 属于表皮生长因子受体家族的酪氨酸激酶受体，许多人类癌症过度表达，而正常成人组织则低度表达。人类癌症中 HER-2 的表达与生存率降低、转移增加、凋亡减少和增殖增加有关。赫赛汀是一种靶向并失活 HER-2 的人源化小鼠抗体。在本研究中，赫赛汀被用于将氧化铁富集纳米颗粒递送至 HER-2(+)癌细胞。如果暴露于交变磁场 (AMF)，纳米颗粒会发热。我们测试了 AMF 激活的赫赛汀靶向纳米颗粒选择性杀死 HER-2(+)人类癌细胞的能力。
将赫赛汀偶联的纳米颗粒与正常人类乳腺上皮细胞 (HMEC)(HER-2(-)) 或恶性人类乳腺上皮细胞 (SK-BR-3)(HER-2(+)) 孵育。用赫赛汀或铁染色来检测细胞，并定量检测结合的动力学。在优化了结合条件后，将细胞暴露于抗体靶向或非抗体偶联的纳米颗粒，然后进行洗涤和假处理或暴露于 AMF，并定量细胞死亡。
SK-BR-3 细胞在 3 小时内以递增的量结合赫赛汀靶向纳米颗粒，但不保留非抗体偶联的纳米颗粒。HMEC 则不保留任何纳米颗粒。与 AMF 一起暴露于结合有赫赛汀靶向纳米颗粒的 SK-BR-3 细胞通过凋亡死亡，可通过 Live/Dead 和核形态测定以及释放 LDH 进行定量。在 AMF 处理或不处理的情况下，用这三种测定方法，赫赛汀靶向纳米颗粒处理的假处理 SK-BR-3 细胞、具有或不具有 AMF 处理的 HMEC 细胞，其毒性均未超过基线细胞死亡水平而增加。
这些研究表明，赫赛汀靶向纳米颗粒可通过 AMF 激活后的热疗选择性杀死 HER-2(+)癌细胞。
