Qu Linlin, Chen Yan, Zhang Fan, He Liang
Department of Laboratory Medicine, The First Hospital of Jilin University, Changchun 130021, Jilin, China.
Department of Gastrointestinal Surgery, The First Hospital of Jilin University, Changchun 130021, Jilin, China.
Mol Ther Oncolytics. 2021 Jan 16;20:607-624. doi: 10.1016/j.omto.2021.01.003. eCollection 2021 Mar 26.
Colorectal carcinoma (CRC) ranks as the third most common malignancy. Long non-coding RNA DLGAP1-AS1 was reported to be dysregulated and to play a pivotal role in hepatocellular carcinoma (HCC). This work aims to analyze the functions and molecular basis of DLGAP1-AS1 in CRC progression and 5-fluorouracil resistance. Cell Counting Kit-8 (CCK-8) assay, Transwell assay, flow cytometry, and western blot were utilized to measure the CRC cell activity, invasiveness, and apoptosis. RNA immunoprecipitation (RIP) and dual-luciferase reporter gene assay were adopted to verify the direct mutual action between DLGAP1-AS1 and miR-149-5p. The effect of DLGAP1-AS1 knockdown on tumor growth and chemosensitivity of 5-fluorouracil (5-FU) were investigated in the mouse CRC xenograft models. Functional assays showed that silencing DLGAP1-AS1 expression remarkably inhibited cell proliferation and aggressiveness ability and enhanced apoptosis rate and cell chemosensitivity to 5-FU. In addition, miR-149-5p was identified as a tumor suppressor and a direct downstream target of DLGAP1-AS1 in CRC. Furthermore, miR-149-5p was confirmed to directly bind to TGFB2 and DLGAP1-AS1 could regulate the expression of TGFB2 signaling pathway via miR-149-5p in CRC. These new findings indicate that DLGAP1-AS1 knockdown inhibited the progression of CRC and enhanced the 5-FU sensitivity of CRC cells through miR-149-5p/TGFB2 regulatory axis, suggesting that DLGAP1-AS1 may be a promising therapeutic target for CRC.
结直肠癌（CRC）是第三大常见恶性肿瘤。据报道，长链非编码RNA DLGAP1-AS1表达失调，并在肝细胞癌（HCC）中起关键作用。本研究旨在分析DLGAP1-AS1在CRC进展和5-氟尿嘧啶耐药中的功能及分子基础。采用细胞计数试剂盒-8（CCK-8）法、Transwell法、流式细胞术和蛋白质免疫印迹法检测CRC细胞活性、侵袭性和凋亡情况。采用RNA免疫沉淀（RIP）和双荧光素酶报告基因检测法验证DLGAP1-AS1与miR-149-5p之间的直接相互作用。在小鼠CRC异种移植模型中研究了敲低DLGAP1-AS1对肿瘤生长和5-氟尿嘧啶（5-FU）化疗敏感性的影响。功能实验表明，沉默DLGAP1-AS1表达可显著抑制细胞增殖和侵袭能力，提高凋亡率及细胞对5-FU的化疗敏感性。此外，miR-149-5p被鉴定为CRC中的肿瘤抑制因子及DLGAP1-AS1的直接下游靶点。此外，证实miR-149-5p可直接结合TGFB2，且DLGAP1-AS1可通过miR-149-5p调控CRC中TGFB2信号通路的表达。这些新发现表明，敲低DLGAP1-AS1可通过miR-149-5p/TGFB2调控轴抑制CRC进展并增强CRC细胞对5-FU的敏感性，提示DLGAP1-AS1可能是CRC的一个有前景的治疗靶点。
