Updated project metadata. MircoRNAs are small RNAs which regulate a pleiotropy of cellular processes and are also involved in tumorigenesis, cancer progression and therapy resistance. We investigated the influence of miRNA-200c on chemoresistance of tumor cells. A proteomic approach identified glutathione S-transferases to be differentially expressed when miR-200c was knocked out and cells were treated with the chemotherapeutic drug doxorubicin.