[A study on the effect of Tanshinone II A against human breast cancer in vivo].
OBJECTIVE
To confirm Tanshinone II A's (Tan II A) anti-cancer activity on nude mice bearing human breast cancer cells with estrogen receptor (ER) positive and negative and to elucidate the mechanism of its activity in vivo.


METHODS
Established the animal model of nude mices bearing human breast cell, both ER positive MCF-7 and ER negative MDA-MB-231, each group was divided into 3 subgroups, respectively by intraperitoneal injection of Tan II A at a dose of 30 mg/kg 4 times/week, by gavage of Tamoxifen at a dose of 1 mg/kg 7 times/ week and by solvent control for 4 weeks. All animals were tested for anti-cancer activity including the weights and the volumes of the tumor, apoptosis index by flow cytometry and expression of p53, bcl-2, cerbB-2 by immunohistochemistry method after the treatment.


RESULTS
In MCF-7 group, there were a 33.64% tumor mass volume reduction and a 32.24% tumor mass weight reduction after Tan II A treatment; in MDA-MB-231 group, a 38.34% tumor mass volume reduction and a 39.82% tumor mass weight reduction were observed in Tan II A subgroups; the differences between Tan II A and Tamoxifen or solvent control were statistically significant in both groups (P < 0.05); increase of apoptosic fiction by flow cytometry examination in Tan II A subgroups in both MCF-7 (48.31% +/- 5.84%) and MDA-MB-231(50.25% +/- 5.03%) groups were observed, there were both significant differences between Tan II A and the other subgroups (P < 0.05). Statistically significant decrease of p53 and bcl-2 expression were observed in Tan lI A between solvent control subgroup in both MCF-7 and MDA-MB-231 groups (P < 0.05) while cerbB-2 had no significant difference with control group (P > 0.05).


CONCLUSIONS
Tan lI A can inhibit both breast cancer cell MCF-7 and MDA-MB-231 growth in vivo, which had better anti-cancer effect than Tamoxifen. The mechanism may be associated with the induction of apoptosis, down regulation of the expression level of gene bcl-2 and p53, but may not with the expression level of cerbB-2.
Zhang
Xin
X
Department of Thyroid and Breast Surgery, West China Hospital, Sichuan University, Chengdu 610041, China.
Zhang
Pu-Rong
PR
Chen
Jie
J
Lü
Qing
Q
D045784:Abietanes / Q000627:therapeutic use*; D000818:Animals; D000972:Antineoplastic Agents, Phytogenic / Q000627:therapeutic use*; D017209:Apoptosis / Q000187:drug effects; D001943:Breast Neoplasms / Q000188:drug therapy*; D045744:Cell Line, Tumor; D005260:Female; D006801:Humans; D051379:Mice; D008807:Mice, Inbred BALB C; D009368:Neoplasm Transplantation; D011897:Random Allocation; D011960:Receptors, Estrogen / Q000378:metabolism; D023041:Xenograft Model Antitumor Assays
D045784:Abietanes; D000972:Antineoplastic Agents, Phytogenic; D011960:Receptors, Estrogen; C021751:tanshinone