Oncogenic CD44 is essential for pancreatic cancer tumorigenesis: A novel targeted therapeutic strategy

Figure 5 CD44 knockout markedly reduces the expression of oncogenic X-inactive-specific transcript and various other tumorigenic genes in pancreatic cancer cells. A and B: The gene expression profiles in three independent sets of CD44-KO and control CD44-expressing Panc-1 cells were analyzed by RNA sequencing (RNA-Seq), and a volcano map of the gene expression profiles is depicted in Figure 5B, red: Up-regulated genes; green: Down-regulated genes; black: Gene expression levels did not significantly change; C: RNA-Seq showed that CD44 knockout markedly reduced the expression levels of oncogenic X-inactive-specific transcript (Xist); D: The expression levels of various other tumorigenic genes in CD44-KO Panc-1 cells were also significantly diminished compared to those in control cells; E: To further confirm CD44 knockout-mediated Xist expression, three Xist primers (P1, P2, and P3) were designed at the indicated position of the long non-coding RNA Xist (19260 bp); F and G: Xist expression levels in CD44-KO and control CD44-expressing Panc-1 cells were detected by real-time PCR and real-time quantitative PCR, respectively; H: To study the effect of CD44 on Xist gene transcription, a promoter region DNA fragment (530 bp) of the Xist gene was cloned into the pGL-4.17-luciferase vector, and the construct was used to transfect CD44-KO and CD44-expressing Panc-1 cells, respectively; I: Luciferase activity in these cells was determined and statistically analyzed. Data are shown as the mean ± SD of three independent replicates. ^aP < 0.05, ^bP < 0.01 vs CD44-NT in an unpaired t test.