Objective       To establish a carboplatin (CBP)-resistant tongue squamous carcinoma cell line

Tca8113/CBP cells

and to observe the reversal effect of neferine in these cells.      Methods       Tca8113/CBP cell line was established by gradually increasing the concentration of carboplatin and intermittent inducement to Tca8113 cells. Methyl thiazolyl tetrazolium (MTT) assay was used to evaluate the reversal effect of neferine on proliferation in Tca8113/CBP cells. mRNA expression of drug-resistance-associated genes

lung related resistant protein (LRP) and fibroblast muscle-type tropomyosin (FMT) were monitored by RT-PCR in the cells before and after resistance establishment. Morphology of the cells was observed under fluorescent microscopy

and the intracellular changes of cytoskeleton between reversed Tca8113/CBP and non-reversed Tca8113/CBP were compared.      Results       After 5 month’s CBP treatment

Tca8113/CBP cells which can be stably resistant to carboplatin (16 μg/ml) was successfully established. The resistance index is 4.06. Neferine reversed the resistance of Tca8113/CBP cells with a reversal fold of 2.12. Compared to the Tca8113 cells

the expression of LRP and FMT at mRNA level was increased obviously in Tca8113/CBP cells. Whereas they were decreased after neferine treatment (P0.01)

and the intracellular F-actin content was also decreased

arranged in neat rows

more evenly distributed close to the level of non-resistant Tca8113 cells .      Conclusion       Neferine exhibits the reversal effect on Tca8113/CBP cells

which may be relate to decrease of LRP and FMT expression

increase of intracellular content of carboplatin

change of the microfilament

reduce of mechanical properties of adhesion

and interference of cell cycle in Tca8113/CBP cells.