OBJECTIVETo investigate anticancer effect of hydroxycamptothecine and theprubicine in the treatment of established human adenoid cystic carcinoma (ACC) lung metastasis of nude mice and to determine the best therapy sequence of the two drugs.

METHODSThe model of ACC lung metastasis (60 animals) was established by injecting the ACC-M cells into the nude mice from their tail veins. Animals were divided into six groups: v acuity control group, HCPT group, THP group, HCPT and THP group 1, HCPT and THP group 2, HCPT and THP group 3 (No.1 - No.6). Different treatment sequence was performed on these groups. The lung samples were collected and observed after HE staining. The area of metastases and lung tissue were analyzed by the images analysis system.

RESULTSThe size of the metastatic lesion in the treatment groups were smaller than that in the control group (P < 0.01). The treatment effects between the group with simultaneous administration of HCPT and THP and the group with single drug administration were not different (P > 0.05). No.5 and No.6 groups showed better effect of treatment than the other treatment groups (P < 0.05).

CONCLUSIONSThere are two recommended sequences: (1) HCPT should be used after THP; (2) THP is used 48 hours, After HCPT is administered. Because using two drugs together will decrease the anticancer effect, HCPT and THP should not be used simultaneously.