Carver Kyle, Ming Xin, Juliano Rudy L
Division of Molecular Pharmaceutics, Eshelman School of Pharmacy, University of North Carolina , Chapel Hill, North Carolina.
Nucleic Acid Ther. 2014 Dec;24(6):413-9. doi: 10.1089/nat.2014.0493.
Standard tissue culture has often been a poor model for predicting the efficacy of anti-cancer agents including oligonucleotides. In contrast to the simplicity of monolayer tissue cultures, a tumor mass includes tightly packed tumor cells, tortuous blood vessels, high levels of extracellular matrix, and stromal cells that support the tumor. These complexities pose a challenge for delivering therapeutic agents throughout the tumor, with many drugs limited to cells proximal to the vasculature. Multicellular tumor spheroids are superior to traditional monolayer cell culture for the assessment of cancer drug delivery, since they possess many of the characteristics of metastatic tumor foci. However, homogeneous spheroids comprised solely of tumor cells do not account for some of the key aspects of metastatic tumors, particularly the interaction with host cells such as fibroblasts. Further, homogeneous culture does not allow for the assessment of targeted delivery to tumor versus host cells. Here we have evaluated delivery of targeted and untargeted oligonucleotide nanoconjugates and of oligonucleotide polyplexes in both homogeneous and composite tumor spheroids. We find that inclusion of fibroblasts in the spheroids reduces delivery efficacy of the polyplexes. In contrast, targeted multivalent RGD-oligonucleotide nanoconjugates were able to effectively discriminate between melanoma cells and fibroblasts, thus providing tumor-selective uptake and pharmacological effects.
标准组织培养常常是预测包括寡核苷酸在内的抗癌药物疗效的不佳模型。与单层组织培养的简单性不同，肿瘤块包含紧密堆积的肿瘤细胞、曲折的血管、高水平的细胞外基质以及支持肿瘤的基质细胞。这些复杂性对在整个肿瘤中递送治疗药物构成了挑战，许多药物只能作用于靠近血管的细胞。多细胞肿瘤球体在评估癌症药物递送方面优于传统的单层细胞培养，因为它们具有转移性肿瘤灶的许多特征。然而，仅由肿瘤细胞组成的均匀球体并未考虑转移性肿瘤的一些关键方面，特别是与宿主细胞（如成纤维细胞）的相互作用。此外，均匀培养无法评估靶向递送至肿瘤细胞与宿主细胞的情况。在这里，我们评估了靶向和非靶向寡核苷酸纳米缀合物以及寡核苷酸多聚体在均匀和复合肿瘤球体中的递送情况。我们发现，球体中包含成纤维细胞会降低多聚体的递送效率。相比之下，靶向多价RGD - 寡核苷酸纳米缀合物能够有效区分黑色素瘤细胞和成纤维细胞，从而实现肿瘤选择性摄取和药理作用。
