cDNA Microarray Study to Identify Expression Changes Relevant for Apoptosis in K562 Cells Co-Treated with Amifostine and Imatinib

BIANCHINI M, MARTINELL GI, RENZULL MI, GONZÁLEZ CID, M, LARRIPA I.

CANCER CHEMOTHERAPY AND PHARMACOLOGY

Springer-Verlag

Lugar: Berlín; Año: 2007 vol. 59 p. 349 - 360

0344-5704

Abstract Background and objective: Chronic myeloid leukaemia (CML) is a clonal myeloproliferative disorder characterized by the presence of the fusion gene BCR/ABL. We had previously demonstrated an increased proapoptotic effect of Imatinib (STI571) in combination with Amifostine (AMI) in K562 cell line. In this study we used genomic scale gene expression profiling to monitor changes at transcriptional level in K562 cells during the treatment with AMI+STI571. Design and methods: cRNA from Control and Treated K562 cells were mixed in equal amounts and incubated with a microarray slide for hybridisation. RNA from six independent paired experiments was subjected to transcriptional profiling. With the aim to automate the process of biological theme determination, selected genes were further analysed by EASE. Validation of the expression was carried out by semiquantitative real-time PCR. Results: As expected a small percentage of genes accounts for the effects of the combined drug treatment. We identified 70 sequences corresponding to known genes; seventeen of the 70 genes were up-regulated, such as RHO6, PPP2R5E, and BTF that appear to reflect favourable events for apoptosis induction. Between down regulated genes, API5, TUBB2 and TLK1 are also of considerable interest. Interpretation and conclusions:  We identified a transcriptional repressor of survival genes, known as BTF, which triggers a pro-apoptotic signal, potentially helpful to overcome the resistance to STI571. This finding could be particularly useful to design novel therapeutic strategies for leukaemia patients. This study demonstrates the importance of in vitro testing of a novel drug combination most likely to predict its potential usefulness for in vivo application.