Since their description in the late 1990s, Human Artificial Chromosomes (HACs) bearing functional kinetochores have been considered as promising systems for gene delivery and expression. More recently a HAC assembled from a synthetic alphoid DNA array has been exploited in studies of centromeric chromatin and in assessing the impact of different epigenetic modifications on kinetochore structure and function in human cells. This HAC was termed the alphoidtetO-HAC, as the synthetic monomers each contained a tetO sequence in place of the CENP-B box that can be targeted specifically with tetR-fusion proteins. Studies in which the kinetochore chromatin of the alphoidtetO-HAC was specifically modified, revealed that heterochromatin is incompatible with centromere function and that centromeric transcription is important for centromere assembly and maintenance. In addition, the alphoidtetO-HAC was modified to carry large gene inserts that are expressed in target cells under conditions that recapitulate the physiological regulation of endogenous loci. Importantly, the phenotypes arising from stable gene expression can be reversed when cells are "cured" of the HAC by inactivating its kinetochore in proliferating cell populations, a feature that provides a control for phenotypic changes attributed to expression of HAC-encoded genes. AlphoidtetO-HAC-based technology has also been used to develop new drug screening and assessment strategies to manipulate the CIN phenotype in cancer cells. In summary, the alphoidtetO-HAC is proving to be a versatile tool for studying human chromosome transactions and structure as well as for genome and cancer studies.

中文翻译：

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具有调节着丝粒的人类人工染色体：基因组和癌症研究的工具。

自从 1990 年代后期被描述以来，带有功能性动粒的人类人工染色体 (HAC) 被认为是基因传递和表达的有前途的系统。最近，由合成 alphoid DNA 阵列组装而成的 HAC 已被用于着丝粒染色质研究和评估不同表观遗传修饰对人体细胞动粒结构和功能的影响。这种 HAC 被称为 alphoidtetO-HAC，因为每个合成单体都包含一个 tetO 序列来代替 CENP-B 框，可以用 tetR 融合蛋白特异性靶向。alphoidtetO-HAC 的动粒染色质经过专门修饰的研究，揭示异染色质与着丝粒功能不相容，着丝粒转录对于着丝粒组装和维持很重要。此外，alphoidtetO-HAC 被修改为携带大型基因插入片段，这些插入片段在重现内源基因座生理调节的条件下在靶细胞中表达。重要的是，当细胞通过灭活增殖细胞群中的动粒来“治愈”HAC 时，可以逆转由稳定基因表达引起的表型，这一特征提供了对归因于 HAC 编码基因表达的表型变化的控制。基于 AlphoidtetO-HAC 的技术还被用于开发新的药物筛选和评估策略，以操纵癌细胞中的 CIN 表型。总之，