a Department of Medical Biotechnology, Faculty of Medical Sciences , Tarbiat Modares University , Tehran , Iran.
b Department of Biochemistry, School of Allied Medical Sciences , Iran University of Medical Sciences , Tehran , Iran.
Artif Cells Nanomed Biotechnol. 2018;46(sup3):S105-S115. doi: 10.1080/21691401.2018.1489269. Epub 2018 Sep 22.
According to the cancer stem cell (CSC) theory, a small subset of cells with stem cell-like characteristics is responsible for tumor initiation, progression, and recurrence. CD44/CD24 phenotype is assumed to be one of the main characteristics of the breast CSCs. We developed an MDA-MB-231 cell line overexpressing cell surface HER2 antigen for the evaluation of targeting efficiency of anti-HER2 nanobody (Nb)-conjugated polyamidoamine (PAMAM) polyplexes. Apoptosis-inducing tBid gene under control of CXCR1 promoter was delivered by this nanoparticle. Cellular uptake study showed higher uptake of Nb-targeted PAMAM carriers compared to non-targeted nanoparticles after 6 h of incubation. Gene expression analysis showed a significant rise in the expression of tBid in both MDA-MB-231/HER2 and MDA-MB-231 compared to the two other cell lines. The same effect was observed after transfection with Nb-conjugated polyplexes within MDA-MB-231/HER2 cell line compared to non-conjugated PAMAM polyplexes. We confirmed the killing efficiency of the gene construct in both MDA-MB-231/HER2 and MDA-MB-231 cell lines by caspase 3 activity assay. These findings suggest that imposing pre-entry and post-entry restrictions on tBid killer gene might be a promising approach to specifically target the breast CSCs.
根据癌症干细胞（CSC）理论，一小部分具有干细胞样特征的细胞负责肿瘤的起始、进展和复发。CD44/CD24 表型被认为是乳腺 CSCs 的主要特征之一。我们开发了一种 MDA-MB-231 细胞系，该细胞系过表达细胞表面 HER2 抗原，用于评估抗 HER2 纳米抗体（Nb）-缀合聚酰胺胺（PAMAM）聚轮烷的靶向效率。这种纳米颗粒携带受 CXCR1 启动子控制的诱导细胞凋亡的 tBid 基因。细胞摄取研究表明，在孵育 6 小时后，与非靶向纳米颗粒相比，Nb 靶向 PAMAM 载体的摄取更高。基因表达分析显示，与其他两种细胞系相比，MDA-MB-231/HER2 和 MDA-MB-231 细胞系中 tBid 的表达显著升高。在 MDA-MB-231/HER2 细胞系中，与非共轭 PAMAM 聚轮烷相比，用 Nb 缀合的聚轮烷转染后也观察到了相同的效果。我们通过 caspase 3 活性测定证实了该基因构建体在 MDA-MB-231/HER2 和 MDA-MB-231 细胞系中的杀伤效率。这些发现表明，对 tBid 杀伤基因施加进入前和进入后限制可能是一种有前途的方法，可特异性靶向乳腺 CSCs。
