Background/Objectives: Early and aggressive metastasis is a major feature of pancreatic ductal adenocarcinoma. Understanding the processes underlying metastasis is crucial for making a difference to disease outcome. Towards these ends, we looked in a comprehensive manner for genes that are metastasis-specific.Methods: A genome-wide CRISPR-Cas9 gene knockout screen with 259,900 single guide RNA constructs was performed on pancreatic cancer cell lines with very high or very low metastatic capacity, respectively. Functional aspects of some of the identified genes were analysed in vitro. The injection of tumour cells with or without a gene knockout into mice was used to confirm the effect on metastasis.Results: The knockout of 590 genes—and, with higher analysis stringency, 67 genes—affected the viability of metastatic cells substantially, while these genes were not vital to non-metastasizing cells. Further evaluations identified different molecular processes related to this observation. One of the genes wasMYBL2, encoding for a well-known transcription factor involved in the regulation of cell survival, proliferation, and differentiation in cancer tissues. In our metastasis-focussed study, no novel functional activity was detected forMYBL2, however. Instead, a metastasis-specific transformation of its genetic interaction withFOXM1was observed. The interaction was synergistic in cells of low metastatic capacity, while there was a strong switch to a buffering mode in metastatic cells. In vivo analyses confirmed the strong effect ofMYBL2on metastasis.Conclusions: The genes found to be critical for the viability of metastatic cells form a basis for further investigations of the processes responsible for triggering and driving metastasis. As shown forMYBL2, unexpected processes of regulating metastasis might also be involved.
**背景/目的：** 胰腺导管腺癌的主要特征之一是早期且侵袭性的转移。理解转移的潜在过程对于改善疾病预后至关重要。为此，我们以全面方式寻找了转移特异性的基因。 **方法：** 分别对具有极高和极低转移能力的胰腺癌细胞系进行了全基因组CRISPR-Cas9基因敲除筛选，使用了259,900个单向导RNA构建体。对部分已识别基因的功能方面进行了体外分析。通过向小鼠注射带有或不带有基因敲除的肿瘤细胞，以确认其对转移的影响。 **结果：** 敲除590个基因（在更高分析严谨性下为67个基因）显著影响了转移细胞的活力，而这些基因对非转移细胞并非至关重要。进一步的评估确定了与此观察相关的不同分子过程。其中一个基因是MYBL2，它编码一种众所周知的转录因子，参与癌组织中细胞存活、增殖和分化的调控。然而，在我们以转移为重点的研究中，未检测到MYBL2具有新的功能活性。相反，观察到了其与FOXM1基因相互作用在转移特异性上的转变。这种相互作用在低转移能力细胞中是协同的，而在转移细胞中则强烈转变为缓冲模式。体内分析证实了MYBL2对转移的强烈影响。 **结论：** 所发现的、对转移细胞活力至关重要的基因为进一步研究触发和驱动转移的过程奠定了基础。正如MYBL2所示，可能还涉及调控转移的意外过程。
肿瘤(癌症)患者之家