Experimental study on ultrasound-guided intratumoral injection of "Star-99" in treatment of hepatocellular carcinoma of nude mice.

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.