Endoscopy Center, Zhongshan Hospital of Fudan University, Shanghai, 200032, People's Republic of China.
Endoscopy Research Institute of Fudan University, Shanghai, 200032, People's Republic of China.
Int J Nanomedicine. 2021 Mar 19;16:2323-2335. doi: 10.2147/IJN.S287732. eCollection 2021.
Colon cancer (CRC) was a malignant tumor and there were about 25% of patients with tumor metastasis at diagnosis stage. Chemotherapeutic agents for metastatic CRC patients were with great side effects and the clinical treatment results of advanced CRC were still not satisfactory. Human epidermal growth factor receptor 2 (HER2) is overexpressed in some CRC patients and is an effective target for CRC patient treatment. Anti-HER2 therapy had a beneficial role in the treatment of HER2-positive metastatic CRC with fewer side effects. CRC patients with BRAF mutations were resistant to HER2 antibodies treatment. Therefore, there was an urgent need to develop new therapeutic agents.
HER2 targeted nanoparticles (TPLNP) drug delivery system loading triptolide (TPL) were prepared and identified. The effects of TPLNP and free TPL on cell viability, targeting and cell cycle progression on HT29 (BRAF mutation) with HER2 overexpression, were evaluated by Cell Counting Kit-8 (CCK8), Fluorescence Activating Cell Sorter (FACS) and immunofluorescence methods, respectively. The anti-tumor efficacies of TPLNP were evaluated in subcutaneous xenograft model of colon cancer and the survival rate, tumor volume, liver and kidney indexes of tumor-bearing mice were measured.
TPLNP was small in nanosize (73.4±5.2nm) with narrow size distribution (PDI=0.15±0.02) and favorable zeta potential (pH=9.6, zeta potential: -57.3±6.69mV; pH=7.0, zeta potential: -28.7±5.1mV; pH=5.6, zeta potential: -21.1±4.73mV). Comparing with free TPL treatment group, TPLNP developed stranger colon cancer-killing efficiency in a dose- and time-dependent manner detected with CCK8 method; achieved good in vitro colon cancer targeting detected with flow cytometry and immunofluorescence experiments; enhanced more HT29-HER2 apoptosis and induced more cell cycle arrested in G1-S phase detected with FACS in vitro. As for in vivo antitumor response, TPLNP remarkably inhibited the growth of colon cancer in the colon cancer xenograft model, significantly improved the survival rate and did not exhibit significant liver and kidney toxicity in contrast with free TPL in vivo.
TPLNP was effectively against colon cancer with HER2 overexpression and BRAF mutation in pre-clinical models. In summary, the TPLNP appeared to be a promising treatment option for CRC in clinical application based on improved efficacy and the favorable safety profile.
结肠癌（CRC）是一种恶性肿瘤，约有 25%的患者在诊断时就已发生肿瘤转移。转移性 CRC 患者的化疗药物具有很大的副作用，晚期 CRC 的临床治疗效果仍不尽人意。人表皮生长因子受体 2（HER2）在一些 CRC 患者中过度表达，是 CRC 患者治疗的有效靶点。抗 HER2 治疗在治疗 HER2 阳性转移性 CRC 方面具有良好的作用，且副作用较少。BRAF 突变的 CRC 患者对 HER2 抗体治疗有耐药性。因此，迫切需要开发新的治疗药物。
制备并鉴定载三萜内酯（TPL）的 HER2 靶向纳米颗粒（TPLNP）药物传递系统。通过细胞计数试剂盒-8（CCK8）、荧光激活细胞分选（FACS）和免疫荧光方法分别评估 TPLNP 和游离 TPL 对 HT29（BRAF 突变）中细胞活力、靶向和细胞周期进展的影响。在结肠癌皮下移植瘤模型中评估 TPLNP 的抗肿瘤疗效，并测量荷瘤小鼠的存活率、肿瘤体积、肝肾功能指标。
TPLNP 为纳米级（73.4±5.2nm），粒径分布较窄（PDI=0.15±0.02），具有良好的zeta 电位（pH=9.6，zeta 电位：-57.3±6.69mV；pH=7.0，zeta 电位：-28.7±5.1mV；pH=5.6，zeta 电位：-21.1±4.73mV）。与游离 TPL 治疗组相比，TPLNP 通过 CCK8 法检测呈剂量和时间依赖性的更强的结肠癌杀伤效率；通过流式细胞术和免疫荧光实验检测到良好的体外结肠癌靶向性；通过 FACS 在体外诱导更多的 HT29-HER2 细胞凋亡并诱导更多的细胞周期停滞在 G1-S 期。在体内抗肿瘤反应方面，TPLNP 可显著抑制结肠癌异种移植模型中结肠癌的生长，与游离 TPL 相比，可显著提高存活率，且无明显肝肾功能毒性。
TPLNP 在临床前模型中对 HER2 过表达和 BRAF 突变的结肠癌具有明显疗效。综上所述，TPLNP 似乎是一种很有前途的 CRC 临床应用治疗方案，其疗效得到了改善，安全性也较好。
