Figure 6. DDX21-PLOR1B signaling axis regulated by lncRNA ZFAS1 in CRC cells and tissues. (A and B) The mRNA expression of POLR1B after overexpression or silencing lncRNA ZFAS1 in SW620 and SW480 cells by RT-PCR (A) and qPCR assay (B). (C and D) The expression levels of POLR1B after interfering DDX21 expression in both SW620 and SW480 cells detected by western blot (C) and qPCR assay (D). (E and F) Rescue experiments determining the POLR1B mRNA and protein expression levels treated by silencing of lncRNA ZFAS1 and overexpression of DDX21 in SW620 and SW480 cells assayed by qPCR assay (E) and western blot assay (F). (G) Representative analysis results of POLR1B expression in paired CRC tissues and controls assayed by RT-PCR and qPCR method. 5 representative data was shown. (H) Representative IHC imagines and Violin charts displaying the POLR1B protein expression based on the CRC patient tissues and matched tumor-adjacent controls (n = 157). The bar represents 100μm. (I) Linear regression analysis illustrating a positive correlation between the expression of POLR1B and LncRNA ZFAS1 or DDX21. (J and K) Stratified Kaplan-Meier plot illustrating the impact of POLR1B high/low expression on the DFS and OS upon those patients with DDX21 high expression (J) or with ZFAS1 high expression (K). Data were shown as mean ± s.d. Two-tailed Student’s t-tests were used. *P <0.05; **P <0.01; ***P <0.001; ****P <0.0001.