Arsenic trioxide induces apoptosis of human gastrointestinal cancer cells

Figure 1 Morphology of apoptotic cells in gastrointestinal cancer seen under light microscopy. The number of apoptotic cells increased following a 3-d period of As₂O₃ treatment. Typical apoptotic changes were seen in GIC cells after As₂O₃ treatment, including cellular shrinkage, cell nucleus fragmentation, chromatin condensation, and the appearance of apoptotic bodies. A: Before As₂O₃ treatment; B: After As₂O₃ treatment (HE × 40).

Figure 2 Human gastrointestinal cancer cells were observed by transferase dUTP nick end labelling assay, and identified by brown-stained nuclei. The number of apoptotic cells was counted in order to calculate the apoptotic index. A: Gastric cancer before As₂O₃ treatment; B: Gastric cancer after As₂O₃ treatment: C: Colon cancer before As₂O₃ treatment; D: Colon cancer after As₂O₃ treatment (× 400).

Figure 3 p53 protein expression in human gastrointestinal cancer cells as indicated by brown-stained nuclei. A: Gastric cancer before As₂O₃ treatment; B: Gastric cancer after As₂O₃ treatment; C: Colon cancer before As₂O₃ treatment; D: Colon cancer after As₂O₃ treatment (× 400).

Figure 4 Bcl-2 protein expression in human gastrointestinal cancer cells as indicated by brown-stained cytoplasm. A: Gastric cancer before As₂O₃ treatment; B: Gastric cancer after As₂O₃ treatment; C: Colon cancer before As₂O₃ treatment; D: Colon cancer after As₂O₃ treatment (× 400).

Figure 5 Linear correlation analyses between apoptotic index and Bcl-2 expression in gastric cancer (A) and colon cancer (B) (%). Data are given as mean ± SD. No significant correlation was detected.