Journal: Non-coding RNA Research
Article Title: CircSMAD4 shapes matrix-remodeling TAMs in lung adenocarcinoma
doi: 10.1016/j.ncrna.2026.03.003
Figure Lengend Snippet: circSMAD4 facilitates IGF2BP2-dependent stabilization of m6A-marked transcripts. (A) Venn diagram intersecting ENCORI-predicted IGF2BP2 targets with DEGs from shIGF2BP2 versus shNC and shcircSMAD4 versus shNC mRNA-seq, identifying shared candidates. (B) MeRIP–qPCR showing m6A enrichment on COL4A1, SPI1, and ACTA2 candidate regions (CRDs) in shNC and shIGF2BP2 cells. (C) IGF2BP2-RIP–qPCR showing IGF2BP2 binding to COL4A1, SPI1, and ACTA2 CRDs in shNC + Vector, shcircSMAD4 + Vector, shNC + IGF2BP2, and shcircSMAD4 + IGF2BP2 groups. (D) Biotin-circSMAD4 pull-down followed by qPCR showing enrichment of COL4A1, SPI1, and ACTA2 CRDs in Vector + shNC, circSMAD4 + shNC, Vector + shIGF2BP2, and circSMAD4 + shIGF2BP2 groups. (E–G) Schematics of m6A-site mutations introduced into COL4A1, SPI1, and ACTA2 reporters. (H–J) Dual-luciferase assays for CRD reporters (WT and m6A-mutant) in Vector, circSMAD4, and IGF2BP2 groups. (K–M) MeRIP–qPCR for WT and m6A-mutant CRD reporters in Vector, circSMAD4, and IGF2BP2 groups. (N–P) mRNA decay assays of endogenous COL4A1, SPI1, and ACTA2 following circSMAD4 knockdown with Vector or IGF2BP2 overexpression. Half-life estimated by one-phase decay (Y0 = 1, Plateau = 0). (Q–S) mRNA decay assays of endogenous COL4A1, SPI1, and ACTA2 following circSMAD4 overexpression with shNC or shIGF2BP2. Half-life estimated by one-phase decay (Y0 = 1, Plateau = 0). ∗P < 0.05; ∗∗P < 0.01; ∗∗∗P < 0.001; ∗∗∗∗P < 0.0001; ns, not significant.
Article Snippet: Gene silencing was performed using lentiviral shRNAs. shRNAs targeting the human circSMAD4 back-splice junction (and the murine circSmad4 ortholog, avoiding linear Smad4) as well as IGF2BP2 were cloned into the pLKO.1-puro vector (Addgene, #8453).
Techniques: Binding Assay, Plasmid Preparation, Luciferase, Mutagenesis, Knockdown, Over Expression