FLI1 Exonic Circular RNAs as a Novel Oncogenic Driver to Promote Tumor Metastasis in Small Cell Lung Cancer
FLI1 Exonic Circular RNAs as a Novel Oncogenic Driver to Promote Tumor Metastasis in Small Cell Lung Cancer
复制标题
FLI1 外显子环状 RNA 作为促进小细胞肺癌肿瘤转移的新型致癌驱动因素
DOI：
10.1158/1078-0432.ccr-18-1447
复制
发表时间：
2019-02-15
影响因子：
11.5
通讯作者：
Cui, Jiuwei
中科院分区：
文献类型：
--
作者：
Li, Lingyu;Li, Wei;Cui, Jiuwei
目的：Friend白血病病毒整合蛋白1（FLI 1）的异常上调与小细胞肺癌（SCLC）的恶性表型密切相关。有趣的是，通过靶向FLI 1编码区的Cas9 gRNA敲除CRISPR基因和通过靶向FLI 1 mRNA的30区域的shRNA转录后敲低在SCLC细胞中产生了不同的抗转移作用。本研究试图研究FLI 1外显子环状RNA（FECR）是否作为一种新的恶性驱动因素，决定转移表型在SCLC.Experimental设计：FECR的临床相关性进行了检查，在56个原发性SCLC组织和50个非小细胞肺癌（NSCLC）组织。通过测量SCLC患者纵向队列中的血清外泌体FECRs来检查FECRs的预后价值。在SCLC细胞系和动物异种移植研究中研究了FECR的致癌活性。最后，我们探讨了这些非编码RNA作为恶性drivers.Results的分子机制：CRISPR Cas9敲除和FLI 1的shRNA敲除的治疗比较确定FECRs作为SCLC中的新的非典型恶性驱动。RNA FISH和定量PCR检测发现FECR 1（exon 4-2-3）和FECR 2（exon 5-2-3-4）在SCLC组织中异常表达（P < 0.0001），且与淋巴结转移呈正相关（P < 0.01）。值得注意的是，血清外泌体FECR 1与较差的生存率（P = 0.038）和对化疗的临床反应相关。沉默FECRs显著抑制了两种高度侵袭性SCLC细胞系的迁移，并减少了体内肿瘤转移。从机制上讲，我们发现FECRs隔离并随后灭活肿瘤抑制因子miR 584 - 3 p，导致Rho相关卷曲螺旋蛋白激酶1基因（ROCK 1）的激活。结论：本研究确定FLI 1外显子环状RNA作为一种新的致癌驱动因子，通过miR 584-ROCK 1途径促进肿瘤转移。重要的是，血清外泌体FECR 1可能作为一个有前途的生物标志物，以跟踪疾病进展的小细胞肺癌。
Purpose: The aberrantly upregulated Friend leukemia virus integration 1 (FLI1) is closely correlated with the malignant phenotype of small cell lung cancer (SCLC). It is interesting to note that the CRISPR gene knockout by Cas9 gRNAs that target the FLI1 coding region and the posttranscriptional knockdown by shRNAs that target the 3 0 region of FLI1 mRNA yielded distinct antimetastasis effects in SCLC cells. This study attempts to examine if FLI1 exonic circular RNAs (FECR) function as a new malignant driver that determines the metastatic phenotype in SCLC.Experimental Design: The clinical relevance of FECRs was examined in 56 primary SCLC tissues and 50 non-small cell lung cancer (NSCLC) tissues. The prognostic value of FECRs was examined by measuring serum exosomal FECRs in a longitudinal cohort of patients with SCLC. The oncogenic activity of FECRs was investigated in both SCLC cell lines and animal xenograft studies. Finally, we explored the molecular mechanisms underlying these noncoding RNAs as a malignant driver.Results: Therapeutic comparison of CRISPR Cas9 knockout and shRNA knockdown of FLI1 identified FECRs as a new noncanonical malignant driver in SCLC. Using RNA FISH and quantitative PCR, we found that FECR1 (exons 4-2-3) and FECR2 (exons 5-2-3-4) were aberrantly upregulated in SCLC tissues (P < 0.0001), and was positively associated with lymph node metastasis (P < 0.01). Notably, serum exosomal FECR1 was associated with poor survival (P = 0.038) and clinical response to chemotherapy. Silencing of FECRs significantly inhibited the migration in two highly aggressive SCLC cell lines and reduced tumor metastasis in vivo. Mechanistically, we uncovered that FECRs sequestered and subsequently inactivated tumor suppressor miR584-3p, leading to the activation of the Rho Associated Coiled-Coil Containing Protein Kinase 1 gene (ROCK1).Conclusions: This study identifies FLI1 exonic circular RNAs as a new oncogenic driver that promotes tumor metastasis through the miR584-ROCK1 pathway. Importantly, serum exosomal FECR1 may serve as a promising biomarker to track disease progression of SCLC.