Klin Onkol 2000; 13(Speciál2 2000): 55-57.
Summary: Multidrug resistance is one of the major causes of treatment failure in NSCLC. Two types of multidrug resistance (MDR) have been detected in lung cancer: typical multidrug resistance associated with the overexpresion of P-glycoprotein (Pgp) and atypical MDR associated with the expresion of MRP (multidrug resistance protein), altered activity of topoisomerase IIa, increased expression of LRP (lung resistance protein), activation of glutathione S transferase system, etc. This work deals with mutual correlation of imunohistochemical expresion of selected markers of MDR (Pgp, MRP, and topoisomerase IIa) and several markers of tumor differentiation and/or apoptosis - p27, p53, procaspase3 (pcasp3), tissue transglutaminase (Tga) with results of in vitro chemosensitivity assay. 64 formaldehyde fixed and paraffin embedded bioptic specimens were used for indirect immunoperoxidase detection of the above mentioned markers. MTT test was carried out from native tumors of the same group. Significant positive relationships were detected in between p53/MRP (p=0,006), p53/pcasp3 (p = 0,0001), inverse correlation was found between p27 /Tga (p = 0,027). Expression of p53 was positively associated with the resistance to actinomycin-D (p = 0,01), daunorubicin (p = 0,026) and vincristine (p = 0,044). Expression of MRP negatively correlated with in vitro sensitivity to taxol (p = 0,043).
