Department of Chemical Biology and Therapeutics, St. Jude Children's Research Hospital, Memphis, TN, USA.
Department of Foundational Sciences, College of Medicine, Central Michigan University, Mount Pleasant, MI, USA.
BMC Cancer. 2019 Mar 21;19(1):253. doi: 10.1186/s12885-019-5455-1.
Despite its relatively low incidence, pancreatic ductal adenocarcinoma (PDAC) is a leading cause of cancer deaths because of the aggressive growth/metastasis of the tumor, the lack of early symptoms, and the poor treatment options. Basic research to identify potential therapeutic targets for PDAC is greatly needed.
We used a negative-selection genome-wide CRISPR screen to identify essential genes in the PANC-1 human pancreatic carcinoma cell line. We validated the top hits with follow-up siRNA screens, using the HPNE, HPAF-II, AsPC-1, and Mia PaCa-2 cell lines.
The PSMA6 gene was an identified candidate hit after the CRISPR screen, siRNA validation screen, and siRNA deconvolution screen. Spheroid formation assays and flow cytometry analysis showed that PSMA6 is critical for survival in many pancreatic ductal carcinoma cell models. Lastly, as PSMA6 protein is a proteosomal subunit of the 20S core complex, we showed that bortezomib, a proteasome inhibitor, was especially toxic in PANC-1 cells.
Further study of PSMA6 and the proteasome subunit that it encodes, along with other hits identified in our CRISPR screens, may provide valuable insights into potential therapeutic targets for PDAC.
尽管胰腺导管腺癌（PDAC）的发病率相对较低，但由于肿瘤的侵袭性生长/转移、缺乏早期症状以及治疗选择有限，它仍是癌症死亡的主要原因。非常需要开展基础研究以确定 PDAC 的潜在治疗靶点。
我们使用负选择全基因组 CRISPR 筛选来鉴定人胰腺癌细胞系 PANC-1 中的必需基因。我们使用后续的 siRNA 筛选对前几个命中靶点进行了验证，同时还使用了 HPNE、HPAF-II、AsPC-1 和 Mia PaCa-2 细胞系。
CRISPR 筛选、siRNA 验证筛选和 siRNA 解卷积筛选后，PSMA6 基因是一个候选命中靶点。球体形成测定和流式细胞术分析表明，PSMA6 对许多胰腺导管腺癌细胞模型的存活至关重要。最后，由于 PSMA6 蛋白是 20S 核心复合物的蛋白酶体亚基，我们表明蛋白酶体抑制剂硼替佐米在 PANC-1 细胞中特别有毒。
进一步研究 PSMA6 及其编码的蛋白酶体亚基以及我们的 CRISPR 筛选中鉴定出的其他命中靶点，可能为 PDAC 的潜在治疗靶点提供有价值的见解。
