Aim: To investigate the anti-cancer effect and the immunological mechanism of ultrasound-guided intratumoral injection of Chinese medicine "Star-99" in hepatocellular carcinoma (HCC) of nude mice.
Methods: Twenty-eight human hepatocellular carcinoma SMMC-7721 transplanted nude mice, 14 of hypodermically implanted and 14 of orthotopic liver transplanted, were randomly divided into three groups of which 14 mice with Star-99, and 7 with ethanol and saline respectively. Ten days after the transplantation the medicines were injected into the tumors of all the nude mice once every 5 days. After 4 injections the nude mice were killed. The diameters of three dimension of the tumors were measured by high frequency ultrasound before and after the treatment and the tumor growth indexes(*) (TGI) were calculated. Radioimmunoassay was used to detect the serum levels of interleukin-2 (IL-2) and tumor necrosis factor (TNF)-alpha. The tumor tissues were sent for flow cytometry (FCM) DNA analysis. Apoptotic cells were visualized by TUNEL assay. All the experiments were carried out by double blind method.
Results: The TGI of Star-99 group (0.076+/-0.024) was markedly lower than that of the saline group (4.654+/-1.283)(P<0.01). It also seemed to be lower than that of the ethanol group (0.082+/-0.028), but not significantly different (P>0.05). Serum levels of IL-2 and TNF-alpha were markedly higher than those of ethanol group and saline groups (P<0.05). The mean apoptotic index (AI: percentage of TUNEL signal positive cells) in Star-99 group (48.98+/-5.09 %) was significantly higher than that of the ethanol group (11.95+/-2.24 %) and the saline group (10.48+/-3.85 %) (P<0.01). FCM DNA analysis showed that the appearance rate of the apoptosis peak in Srar-99 group was 92.9 %, markedly higher than that of the ethanol group (14.3 %) and the saline group (0.0 %) (P<0.01). Correlation (r=0.499, P<0.05) was found between AI and serum level of TNF-alpha.
Conclusion: Star-99 has an effect on the elevation of the serum levels of IL-2 and TNF-alpha. It indicates that Star-99 has the function of enhancing the cellular immunity and inducing cancer cell apoptosis. The correlation between AI and serum level of TNF-alpha indicates that the elevation of the serum of TNF-alpha induced by Star-99 may be an important factor in the promotion of the hepatic cancer cell apoptosis. Star-99 has strong effects on the inhibition and destruction of cancer cells. Its curative effect is as good as ethanol. Its major mechanisms can be as follows: (1) it increases the serum levels of IL-2 and TNF-alpha and triggers cellular immunity. (2) It can induce cancer cells apoptosis, the effective mechanism of the Star-99 is different from that of the ethanol. The mechanisms of triggering the immunologic function of the organism and inducing cell apoptosis are, of particular significance. This study will provide a new pathway of drug administration and an experimental basis for the treatment of HCC with Chinese herbal, and the study of Star-99 in the treatment of tumor is of profound significance with good prospects.