Colorectal Cancer

DLGAP1-AS1[LncRNA]

miR-149-5p[miRNA]

TGFB2[mRNA]

CRC cells

Mus musculus (mouse)

Mol Ther Oncolytics. 2021 Jan 16;20:607-624. doi: 10.1016/j.omto.2021.01.003. eCollection 2021 Mar 26.

The lncRNA DLGAP1-AS1/miR-149-5p/TGFB2 axis contributes to colorectal cancer progression and 5-FU resistance by regulating smad2 pathway.

RIP assay;RNA immunoprecipitation;Western blot;Flow Cytometry assay;RNA immunoprecipitation;

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.