Effects of microspheres combined with lipiodol embolization on hepatocyte proliferation and apoptosis in rats with liver cancer

Objective To investigate the effects of microspheres combined with lipiodol embolization on hepatocyte proliferation and apoptosis in rats with liver cancer. Methods Thirty successfully established male rat models with liver cancer were randomly divided into the combination group, lipiodol group and model control group (n=10 each) . The three groups were injected with 0.5 ml/kg lipiodol+ 1 ml Embosphere, 0.5 ml/kg lipiodol, and 1.5 ml/kg normal saline through hepatic artery, respectively. At 8 d after the treatment, the tumor growth rate was determined. The apoptosis of liver cancer cells was examined by TUNEL method. Immunohistochemical SP method was used to determine the expression of p53 and Bcl-2 in liver cancer tissues. Results There was statistically significant difference in the tumor growth rate among the three groups (all P<0.05) . The tumor growth rate in the combination group was significantly lower than that in the lipiodol group and model control group[ (2.21±0.64) % vs (10.68±3.08) %, (2.21±0.64) % vs (28.42±9.13) %, both P<0.05]. There was statistically significant difference in the apoptosis rate of liver cancer cells among the three groups (all P<0.05) . The apoptosis rate of liver cancer cells in the combination group was significantly higher than that in the lipiodol group and model control group[ (19.87±5.32) % vs (14.69±4.13) %) , (19.87±5.32) % vs (3.72±1.24) %, both P<0.05]. The immunohistochemical positive staining sites of p53 and Bcl-2 were mainly in the cytoplasm, showing yellow or brown granules. There were statistically significant differences in the positive expression rates of p53 and Bcl-2 among the three groups (all P<0.05) . The positive expression rate of p53 in the combination group was significantly higher than that in the lipiodol group and model control group[ (55.41±5.93) % vs (41.38±6.42) %, (55.41±5.93) % vs (24.36±6.85) %, both P<0.05]. The positive expression rate of Bcl-2 in the combination group was significantly lower than that in the lipiodol group and model control group[ (26.74±7.59) % vs (41.38±6.42) %, (26.74±7.59) % vs (67.25±8.76) %, both P<0.05]. Conclusion Microspheres combined with lipiodol embolization may inhibit the proliferation of liver cancer cells and promote cell apoptosis, which may be achieved by up-regulating the protein expression of p53 and down-regulating the protein expression of Bcl-2. Key words: Liver neoplasms, experimental; Lipiodol; Microspheres; Transcatheter arterial chemoembolization; Proliferation; Apoptosis