Effects of thalidomide on angiogenesis and tumor growth and metastasis of human hepatocellular carcinoma in nude mice

Abstract

Aim: To investigate the effects of thalidomide on angiogenesis, tumor growth and metastasis of hepatocellular carcinoma in nude mice.

Methods: Twenty-four nude mice were randomly divided into therapy group and control group, 12 mice in each group. Thalidomide dissolved in 0.5% sodium carboxyl methyl cellulose (CMC) suspension was administered intraperitoneally once a day at the dose of 200 mg/kg in therapy group, and an equivalent volume of 0.5% CMC in control group. Mice were sacrificed on the 30th d, tumor size and weight and metastases in liver and lungs were measured. CD34 and VEGF mRNA in tumor tissue were detected by immunohistochemistry and semi-quantitative RT-PCR respectively and microvessel density (MVD) was counted. Serum concentrations of TNF-alpha and ALT and AFP were also tested.

Results: MVD and VEGF mRNA in therapy group were less than those in control group (31.08+/-16.23 vessels/HP vs 80.00+/-26.27 vessels/HP, 0.0538+/-0.0165 vs 0.7373+/-0.1297, respectively, P<0.05). No statistical difference was observed in tumor size and weight and metastases in liver and lungs. TNF-alpha was significantly lower in therapy group than in control group (28.64+/-4.64 ng/L vs 42.69+/-6.99 ng/L, P<0.05). No statistical difference in ALT and AFP was observed between groups.

Conclusion: Thalidomide can significantly inhibit angiogenesis and metastasis of hepatocellular carcinoma. It also has inhibitory effects on circulating TNF-alpha.

Figure 1

Tumors in nude mice on the 30th d. Upper line of tumors was HCC in the control group, the lower in therapy group.

Figure 2

Metastases of hepatocellular carcinoma in lungs. Magnification: ×200.

Figure 3

Metastases of hepatocellular carcinoma in lungs and liver. ^aP<0.05. Liver metastases were recorded in a gross manner by examining each lobe of liver and counting macroscopic tumors on the surface. Lung metastases were counted under microscope by observing consecutive paraffin slices of lung.

Figure 4

Immunohistochemical expression of CD34. A: control group; B: thalidomide treated group. Magnification: ×200.

Figure 5

RT-PCR of VEGF mRNA in HCC tissue. M: Marker, 100 bp DNA ladder, ranging from 100 bp to 600 bp; C: Control group; T: Therapy group. The band of VEGF (all isoforms, 196 bp) and G3PDH (450 bp) are shown at expected location in the gel. G3PDH used as an internal standard. VEGF mRNA was expressed strongly in control group, whereas weakly in therapy group.