Tumor protein p53 (TP53) is the most frequently mutated gene in cancer and it regulates a number of genes involved in DNA repair, cell cycle, apoptosis and angiogenesis. Kevetrin is a small compound that showed activity against TP53 wt and mutant solid tumors. We explored, for the first time, the consequences of kevetrin exposure in AML cell lines.
In the present study we addressed the response of AML cell lines to kevetrin treatment and investigated gene expression changes in TP53 mutant and wt models, in order to better understand the molecular and biological consequences of kevetrin exposure.
TP53-wt MOLM-13 and TP53-mut KASUMI-1 were treated with kevetrin [concentration range 15-60 μg/ml]. After 24 and 48 h MTS and Annexin-V were performed. Gene expression profiling (GEP) was performed on cells treated for 6 and 48 h with the highest kevetrin dose (60 μg/ml or no drug control) using Human Transcriptome Array 2.0 (Thermo Scientific). Data quality control and normalization were carried out by Expression Console software. Supervised analysis was performed with Transcriptome Analysis Console software. Functional annotation clustering was performed using David Bioinformatics Resources 6.8. Gene set enrichment analysis (GSEA) was performed with GSEA software.
The TP53-wt cell line showed a sensibility only at the highest drug concentration with a decreased cell viability and a significant increase in Annexin V+ cells (54.95 ± 5.63 % vs 12.53 ± 6.15 % of the CTRL). KASUMI-1 cell line showed a significant dose- and time-dependent cell growth inhibition and apoptosis increase with 79.70 ± 4.57 % of Annexin V+ cells at 60 μg/ml (vs 13.18 ± 0.80 % of the CTRL). Short-term (6 h) kevetrin treatment induced few alterations of the overall transcriptional program, with a differential expression of FOXK2 and STAT5A, which were 2-fold downregulated in KASUMI-1. Moreover, metallothionein 1 and 2 were upregulated by kevetrin exposure in both cell lines. After prolonged kevetrin treatment (48 h) we found 1024 upregulated and 1563 downregulated genes in MOLM-13 cell line, whereas KASUMI-1 showed increased expression of 325 and decreased levels of 1535 genes. Kevetrin exposure targeted also a common core transcriptional program in the selected models, including 162 upregulated and 812 downregulated genes. Enrichment analysis of the core transcripts showed that upregulated genes were mainly involved in transcription, nucleosome assembly and telomere organization, apoptosis, autophagy, NF-kB pathway and MAPK activity. Downregulated genes were mostly involved in cell cycle, DNA repair, biosynthetic processes, bioenergetics, translation, telomere maintenance and splicing. Among the most relevant genes we found critical regulators of myelopoiesis and leukemogenesis, such as MYC, MYB, BCL11A and EZH1, leukemia-related genes involved in unfolded protein response (JUN), signaling, glycolysis (HK2), DNA methylation (IDH2) and the tumor suppressor gene TP53. GSEA of microarray data showed that kevetrin-treated cells shared the downregulation of glycolysis, DNA repair, unfolded protein response and MYC target gene sets (Figure).
Our results show kevetrin alters several key genes and cellular metabolism. Along with cellular data, this study could provide a rationale for an experimental trial in AML patients, especially those carrying TP53 mutation who actually have very few therapeutic options.