Association between Bmi1 and clinicopathological status of esophageal squamous cell carcinoma

Figure 1 Amplification curve (A) and standard curve (B) of quantitative real-time PCR for Bmi1 mRNA. Total RNA was extracted for subsequent reverse transcription, and standard cDNA was serially diluted to obtain five standard solutions (1 × 10^-1, 1 × 10^-2, 1 × 10^-3, 1 × 10^-4, 1 × 10^-5) for use in PCR to generate the reference curve, slope rate of the straight line (a) = -3.42089, intercept (b) = 5.97517, correlation coefficient (r) = 0.9996. The strength of Bmi1 and β-actin was directly generated by the machine.

Figure 2 Staining of ESCC tissues. The tumor cells of cancerous tissues were stained as violet in the nucleus and pink in the cytoplasm (× 100).

Figure 3 Effects of Bmi1 mRNA expression on prognosis of ESCC patients. Two patients did not complete the 5-year follow-up in each group (small circles). The survival rate was higher in the down-expression group (group 2) than in the up-expression group (group 1), χ² = 4.41, P = 0.0356.

Figure 4 Immunohistochemical staining of ESCC using antibody to Bmi-1. A: Bmi1 protein expression in adjacent non-cancerous tissues (× 400); B: Cytoplasm staining of Bmi1 in ESCC cells (× 400); C: Intense Bmi-1 staining in the nucleus in ESCC cells (× 400). The brown staining under light microscopy indicates positivity.