Clustered regularly interspaced short palindromic repeats (CRISPR) is described as RNA mediated adaptive immune system defense, which is naturally found in bacteria and archaea. CRISPR-Cas9 has shown great promise for cancer treatment in cancer immunotherapy, manipulation of cancer genome and epigenome and elimination or inactivation of carcinogenic viral infections. However, many challenges remain to be addressed to increase its efficacy, including off-target effects, editing efficiency, fitness of edited cells, immune response and delivery methods. Here, we explain CRISPR-Cas classification and its general function mechanism for gene editing. Then, we summarize these preclinical CRISPR-Cas9-based therapeutic strategies against cancer. Moreover, the challenges and improvements of CRISPR-Cas9 clinical applications will be discussed.

中文翻译：

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用于癌症治疗的CRISPR / Cas9：技术，临床应用和挑战。

簇状规则间隔的短回文重复序列（CRISPR）被描述为RNA介导的适应性免疫系统防御，它在细菌和古细菌中自然存在。CRISPR-Cas9在癌症免疫疗法中的癌症治疗，癌症基因组和表观基因组的操纵以及致癌性病毒感染的消除或失活方面显示出了广阔的前景。然而，要提高其功效还需要解决许多挑战，包括脱靶效应，编辑效率，编辑细胞的适应性，免疫应答和递送方法。在这里，我们解释CRISPR-Cas分类及其基因编辑的一般功能机制。然后，我们总结了这些基于CRISPR-Cas9的临床前抗癌治疗策略。此外，将讨论CRISPR-Cas9临床应用的挑战和改进。