Journal: Advanced Science
Article Title: A Mammalian Conserved Circular RNA CircLARP1B Regulates Hepatocellular Carcinoma Metastasis and Lipid Metabolism
doi: 10.1002/advs.202305902
Figure Lengend Snippet: CircLARP1B destabilizes LKB1 mRNA via perturbing HNRNPD. a–d) Stability assay of LKB1 mRNA and the steady levels of LKB1 protein (examined by western blotting) in human PLC cells (a,b) and murine Hepa1‐6 cells (c,d) treated siRNA against HNRNPD. siNC, negative control siRNA with scrambled sequences. e) Overall experimental strategy of eIF4E and eIF4G1 RIP assays. RNase I is introduced to digest unprotected RNAs across the IP procedure. Western blots showing HNRNPD knockdown efficiency and efficient IPs of eIF4E and eIF4G1 in PLC cells treated with siRNA against HNRNPD (right). ACTB protein acted as the loading control. f) Primers against various regions of LKB1 mRNA (top) and enrichment of LKB1 mRNA regions with eIF4E or eIF4G1 by RT‐qPCR (bottom). g,h) Stability assay of LKB1 mRNA (g) and the steady levels of LKB1 protein (h) in WT or circLARP1B‐Def PLC cells. i,j) Stability assay of Lkb1 mRNA (i) and the steady levels of Lkb1 protein (j) in Hepa1‐6 cells treated with shcircLARP1B or shCtrl. shCtrl, shRNA control that generates siRNA of scrambled sequences; shcircLARP1B, shRNA against the murine circLARP1B BSJ. k) In vitro competing assay of purified HNRNPD protein for equal moles of in vitro synthesized circLARP1B and LKB1 3′ UTR. An illustration of the assay was shown (top). Semiquantitative RT‐PCR gels and RT‐qPCR for circLARP1B and LKB1 3′ UTR were indicated (bottom). LKB1 3′ UTR, in vitro transcribed LKB1 3′ UTR fragments with the HNRNPD binding sequence. l) Association of LKB1 mRNA examined by RT‐qPCR of HNRNPD RIP in PLC cells treated with oligodeoxynucleotide antisense to two HNRNPD binding motifs in circLARP1B (ODN‐AS) or the control (ODN‐Ctrl, ODN with scrambled sequences). Two motifs with reverse complementary sequences were indicated with underlines. PS, phosphorothioate; 2′‐OMe, 2′‐ O ‐methyl. Western blot images indicate successful IP of HNRNPD protein. Enrichment, normalized to IgG. m) Western blotting and the corresponding quantification showing the steady level of LKB1 protein in PLC cells transfected with ODN‐AS or ODN‐Ctrl. (b,d,h,j,m) The grayscale statistics of western blotting were performed by ImageJ. (a–d,f–m) Data are shown as mean ± SD from three independent experiments. (a,c,g,i) P ‐values by two‐way ANOVA test. (b,d,f,h,j,l,m) P ‐values by two‐tailed unpaired Student's t ‐test.
Article Snippet: The shRNA against the BSJ of human or murine circLARP1B was cloned into the vector pLKO.1 (Sigma) and the negative‐control shRNA (shCtrl, MFCD07785395) was obtained from the MISSION shRNA Library (Sigma).
Techniques: Stability Assay, Western Blot, Negative Control, Quantitative RT-PCR, shRNA, In Vitro, Purification, Synthesized, Reverse Transcription Polymerase Chain Reaction, Binding Assay, Sequencing, Protein Enrichment, Transfection, Two Tailed Test