[Preliminary study on the antitumor immuno-protective mechanism of beta-elemene].
OBJECTIVE
To study the antitumor effects and their molecular mechanism of beta-elemene, which is one of the effective monomers of Oleum Curcuma aromatica, a Chinese anticancer medicament.


METHODS
The expression of membrane protein HSP70 on H22 cells treated with beta-elemene or mitomycin C(MMC) was analysed by immunofluorescence and flow cytometric techniques and the antitumor effects of the treated H22 cells was examined in C57BL/6 mice.


RESULTS
The expression rate or intensity of membrane protein HSP70 of H22 cells treated with beta-elemene, and those treated with MMC was both significantly higher than that of the untreated H22 cells (P < 0.001). Increase in HSP70 expression was most marked when H22 cells were treated with beta-elemene and MMC in combination, with an expression rate of 95.1%. Heat shock treatment of the H22 cells combined with other stress-inducing factors could further increase the HSP70 expression intensity. Specific antitumor immunity could be elicited in C57BL/6 mice immunized with beta-elemene-treated H22 cells, and the effect could be partially blocked by anti-HSP70 mAb. In mice immunized with beta-elemene-treated H22 cells, tumor developed in 3 of 11 mice, while in the immunized mice given anti-HSP70 mAb, 5 out of 10 mice developed tumor, and all of the control mice developed tumor. The average tumor weight (g) on day 28 after challenge with untreated H22 cells was 0.17 +/- 0.33, 0.66 +/- 0.77 and 1.11 +/- 0.58 in the three groups of mice, respectively.


CONCLUSIONS
beta-elemene increases tumor cell immunogenicity by inducing, at least in part, elevated expression of heat shock protein 70 on tumor cell surface.
Wu
W
W
Liver Cancer Institute, Zhongshan Hospital, Shanghai Medical University, Shanghai 200032.
Liu
K
K
Tang
X
X
D000818:Animals; D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology*; D019496:Cancer Vaccines / Q000276:immunology*; D005260:Female; D018840:HSP70 Heat-Shock Proteins / Q000096:biosynthesis; D007114:Immunization; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009374:Neoplasms, Experimental / Q000517:prevention & control*; D010936:Plant Extracts / Q000494:pharmacology; D012717:Sesquiterpenes
D000972:Antineoplastic Agents, Phytogenic; D019496:Cancer Vaccines; D018840:HSP70 Heat-Shock Proteins; D010936:Plant Extracts; D012717:Sesquiterpenes; C445979:beta-elemene