[Expression of MDR1 and KIT in imatinib-resistant gastrointestinal stromal tumor cells].

OBJECTIVE: To explore the relationship between imatinib resistance and genes MDR1 and KIT in gastrointestinal stromal tumor (GIST) cells. METHODS: The MDR1 and KIT mRNA level in GIST882-R and GIST882-S cells were detected by RT-PCR. Immunocytochemistry and Western blot were employed to detect P-gp and CD117 expression in GIST882-R and GIST882-S cells. RESULTS: The relative expression of MDR1 mRNA was 0.321 + or - 0.033 in GIST882-R and 0.157 + or - 0.056 in GIST882-S cells, and the difference was statistically significant (P<0.05). The relative expression of KIT mRNA was 0.389 + or - 0.063 in GIST882-R and 0.339 + or - 0.067 in GIST882-S, and the difference was not statistically significant (P>0.05). The relative density of P-gp was 0.443 + or - 0.058 in GIST882-R and 0.237 + or - 0.094 in GIST882-S, and the difference was statistically significant (P<0.05). The relative density of CD117 was 0.744 + or - 0.123 in GIST882-R and 0.704 + or - 0.094 in GIST882-S, and the difference was not statistically significant (P>0.05). CONCLUSIONS: Over-expression of gene MDR1 may be associated with imatinib resistance in GIST. KIT may not be involved in imatinib resistance.