Immunohistochemical detection of MDR proteins in Wilms' tumour.

Objectives: The aim of our work was to determine the expression of three MDR proteins (MDR1/Pgp, MRP1 and LRP/MVP) in 15 tissue samples of nephroblastoma (Wilms' tumour).

Background: The majority of Wilms' tumours respond well to chemotherapy and are successfully cured, but a small subset displays resistance to therapy. The molecular mechanisms of drug resistance in this tumour type of childhood are still poorly analyzed. In our opinion, the elucidation of reasons for therapy failure in nephroblastomas is urgently needed before cure becomes a reality for children with this cancer.

Methods: To demonstrate these proteins the enzyme indirect immunohistochemical method was used. The brown colour of the diaminobenzidine reaction product allowed us to define the distribution of stain clearly.

Conclusion: Our immunohistochemical analysis did not demonstrate any expression of MDR1 in all cases of nephroblastoma (14 cases were after pre-operative chemotherapy, 1 case wasn't). The analysis of MRP1 and LRP expression in our set revealed 60% positivity for MRP1 and 26.7% positivity for LRP. The ability to recognize the multidrug resistance phenotype might assist in choosing specific chemotherapeutic regimens to improve prognosis and therapy (Tab. 2, Fig. 2, Ref. 20). Full Text (Free, PDF) www.bmj.sk.