Oligonucleotide (ON) concentrations employed for therapeutic applications vary widely, but in general are high enough to raise significant concerns for off target effects and cellular toxicity. However, lowering ON concentrations reduces the chances of a therapeutic response, since typically relatively small amounts of ON are taken up by targeted cells in tissue culture. It is therefore imperative to identify new strategies to improve the concentration dependence of ON function. In this work, we have identified ammonium ion (NH₄⁺) as a non-toxic potent enhancer of ON activity in the nucleus and cytoplasm following delivery by gymnosis. NH₄⁺ is a metabolite that has been extensively employed as diuretic, expectorant, for the treatment of renal calculi and in a variety of other diseases. Enhancement of function can be found in attached and suspension cells, including in difficult-to-transfect Jurkat T and CEM T cells. We have also demonstrated that NH₄⁺ can synergistically interact with arsenic trioxide (arsenite) to further promote ON function without producing any apparent increased cellular toxicity. These small, inexpensive, widely distributed molecules could be useful not only in laboratory experiments but potentially in therapeutic ON-based combinatorial strategy for clinical applications.

中文翻译：

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铵和三氧化二砷在通过gymnosis 递送时是寡核苷酸功能的有效促进剂

用于治疗应用的寡核苷酸 (ON) 浓度差异很大，但通常足够高，足以引起对脱靶效应和细胞毒性的严重关注。然而，降低 ON 浓度会减少治疗反应的机会，因为通常相对少量的 ON 被组织培养中的目标细胞吸收。因此，必须确定新的策略来改善 ON 功能的浓度依赖性。在这项工作中，我们已将铵离子 (NH ₄ ⁺ )鉴定为通过gymnosis 递送后细胞核和细胞质中ON 活性的无毒强效增强剂。NH ₄ ⁺是一种代谢物，已被广泛用作利尿剂、祛痰剂，用于治疗肾结石和各种其他疾病。在附着和悬浮细胞中可以发现功能增强，包括在难以转染的 Jurkat T 和 CEM T 细胞中。我们还证明了 NH ₄ ⁺可以与三氧化二砷（亚砷酸盐）协同作用以进一步促进 ON 功能，而不会产生任何明显增加的细胞毒性。这些小的、便宜的、分布广泛的分子不仅可用于实验室实验，还可用于临床应用的基于 ON 的治疗组合策略。