Increased KIF21B expression is a potential prognostic biomarker in hepatocellular carcinoma

Figure 1 Differential expression of KIF21B in The Cancer Genome Atlas database and hepatocellular carcinoma cell lines. A and B: Differential expression levels of KIF21B in 50 pairs of matched hepatocellular carcinoma and adjacent normal tissues from the The Cancer Genome Atlas database (P < 0.01); C: KIF21B expression was examined in BEL-7404, BEL-7402, Hep-G2, SMMC-7721, and Chang liver cells. All the data were normalized to mRNA expression levels of human GAPDH using the 2^-ΔΔCT method. All the experiments were conducted in triplicate. Data were analyzed by ANOVA or t-test. The data are reported as the mean ± SD. P < 0.05 was considered significant, ^aP < 0.05, ^bP < 0.01.

Figure 2 Knockdown of KIF21B using lentivirus-mediated small interfering RNA in hepatocellular carcinoma BEL-7404 cells. A: The proportion of infected cells in both the shCtrl and shKIF21B groups reached 80%; B: Expression level of KIF21B mRNA in BEL-7404 cells was significantly decreased in the shKIF21B-treated group compared to the shCtrl-treated group; C: Expression level of KIF21B protein significantly increased in the shCtrl-treated group compared to the shKIF21B-treated group (P < 0.01). All the experiments were conducted in triplicate. Data were analyzed by ANOVA or t-test. The data are reported as the mean ± SD. P < 0.05 was considered significant, ^bP < 0.01.

Figure 3 Growth of BEL-7404 cells detected using a Celigo Imaging Cytometer after transfection with short hairpin RNA shCtrl or shKIF21B. A and B: Fluorescence images of cells for each day post-transfection. Data were analyzed by ANOVA or t-test. The data are reported as the mean ± SD. P < 0.05 was considered significant, ^bP < 0.01.

Figure 4 Growth of BEL-7404 cells detected by MTT assay after transfection with short hairpin RNA shCtrl or shKIF21B. Cell proliferation was significantly inhibited in the shKIF21B-transfected group cells. All the experiments were conducted in triplicate. Data were analyzed by ANOVA or t-test. The data are reported as the mean ± SD. P < 0.05 was considered significant, ^bP < 0.01.

Figure 5 Apoptosis of BEL-7404 cells detected by fluorescence-activated cell sorting after transfection with short hairpin RNA shCtrl or shKIF21B. Cell apoptosis was significantly inhibited in the shCtrl-transfected group compared with the shKIF21B-transfected group. All the experiments were conducted in triplicate. Data were analyzed by ANOVA or t-test. The data are reported as the mean ± SD. P < 0.05 was considered significant, ^bP < 0.01.

Figure 6 Self-renewal capacity of BEL-7404 cells detected using colony-forming assays after transfection with short hairpin RNA shCtrl or shKIF21B. Self-renewal capacity of cells was significantly inhibited in the shKIF21B-transfected group cells compared with the shCtrl-transfected group. All the experiments were conducted in triplicate. Data were analyzed by ANOVA or t-test. The data are reported as the mean ± SD. P < 0.05 was considered significant, ^bP < 0.01.

Figure 7 KIF21B expression in hepatocellular carcinoma tissues and normal adjacent tissues. A and B: Low expression of KIF21B in normal adjacent tissues (magnification: ×100 for A and ×400 for B); C and D: High expression of KIF21B in hepatocellular carcinoma tissues (magnification: ×100 for C and ×400 for D); E and F: Kaplan-Meier’s survival curves using a log-rank test demonstrating the correlation between KIF21B expression and overall survival or disease-free survival. Dashed lines indicate high KIF21B expression, and solid lines indicate low KIF21B expression.