OBJECTIVESTo investigate the relationship between the expression of mrp and both the responses to chemotherapy and the level of alpha-fetoprotein (AFP).

METHODSS-P immunohistochemical staining and in situ PCR were adopted to detect MRP and mRNA mrp in 54 cancer tissues taken from untreated HCC patients whose tumor could not be removed during the operation, 24 para-cancer tissues, and 12 posthepatitis cirrhosis paraffin-embedded tissues. The relationship between the expression of mrp and their curative effect to chemotherapy in all the patients was analyzed, so was the relationship between the expression of mrp and the level of AFP in 38 patients whose AFP was positive after operation.

RESULTSThe positive rates of expressing MRP and mRNA mrp in the three kinds of tissues were 61.1%, 25.0%, 33.3% and 77.8%, 37.5%, 41.7%, respectively, with higher rates in HCC tissues than those in other tissues (chi2=9.842, P< 0.01; chi2=13.956, P<0.01). The rates of curative effect to chemotherapy in groups of negative and positive MRP and mRNA mrp expression were 61.9%, 30.3% and 75.0%, 33.3%, respectively, with significant difference between the negative and positive groups (chi2=5.242, P<0.05; chi2=6.627, P< 0.05). As the same as the percentage of curative effect to chemotherapy, the rates of AFP level decreased evidently were 62.5%, 27.3% and 87.5%, 30.0%, with remarkable difference between the two groups (chi2=4.710, P<0.05; chi2=8.566, P<0.05).

CONCLUSIONSThe multidrug resistance (MDR) of HCC is related to mrp expression, which initiates the intrinsic MDR. There is an important significance by detecting mrp expression in selecting chemotherapeutic method, and the expression of mrp can act as an indicator for chemotherapeutic sensitivity in HCC patients.