OBJECTIVETo clarify the relationship between cyclin D1 and cisplatin resistance of Tca8113/cis diamminedichloroplatinum (CDDP) in vitro and in vivo.

METHODSWe applied the transfection method with plasmids pcDNA3.1-antisense-cyclin D1 by Lipofectamine 2000. Tca8113/CDDP cells were used as control. MTT assay was used to identify the proliferation and sensibility of those cells to cisplatin. Subsequently, 18 nude mice were subcutaneously injected by those cells and divided into 3 groups with 6 mice in each group. Every mouse was treated by cisplatin with 5 mg . kg(-1) . d(-1) for 5 days. The sizes of tumor were measured every other day and were described with the growth curves. After 20 days, tumors were anatomized and weighed. The tumor inhibition ratios were calculated and the HE slides were observed to determine the cell sensibility to cisplatin.

RESULTSThe transfected cells with pcDNA3.1-antisense-cyclin D1grew more slowly than other cells and showed higher sensibility to cisplatin in vitro. The tumors developed by cells with pcDNA3.1-antisense-cyclin D1 were smaller than the The tumor inhibition ratio was 74% (P < 0.05). The necrosis area was larger in the tumors developed by the transfected cells with pcDNA3.1-antisense-cyclin D1 than other groups.

CONCLUSIONSAntisense oligonucleotides of cyclin D1 can improve the sensibility of Tca8113/CDDP cells to cisplatin and inhibit the growth of tumors.