Potencial epigenético de hidroxamatos na modulação da expressão de histonas desacetilases (HDACS) em linhagem leucêmica (HL-60)

Abstract

Cancer remains one of the leading causes of death worldwide. Studies with targets in energetic metabolism, combined therapies and genetic and epigenetic modifications have been used to identify the new therapeutic strategy. Bioinformatics studies, such as in silico analysis when associated with preclinical trials experiments, allow the validation of antitumor potential and molecular pathways of new compounds in drug discovery. The hydroxamates have been approved by the FDA (Food and Drug Administration) and are in current use in hematological treatment, due to their efficiency in modulating histone proteins, favouring their genetic silencing via histone deacetylase inhibitors (HDACi). Therefore, this work aims to analyze the in vitro epigenetic potential of two prototypes of the hydroxamate class (LDT565 and LDT566), as potential cellular antitumor agents in the regulation of HDAC1 e HDAC2 gene expression. The experiments to validate the mechanisms of action and biological activity were conducted by toxicity trials, gene expression analysis in a hematological cell line (HL60) and in silico analysis. The commercial compound Vorinostat was used as a positive control. Up to this point, growth activity was observed, time (24h 48h and 72h) and concentration depending, where were found similarities between the synthetic compounds and Vorinostat, but LDT565 stands out for presenting similar IC50 results since 24h of treatment (24h = 1.85; 48h = 1.19 and 72h = 1.43). It was also possible to analyze the inhibition of gene expression for HDAC1 and HDAC2 in 12h incubation between both the prototypes analyzed (LDT565 e LDT566) and the positive control (Vorinostat). After 24h incubation, the compound LDT566 demonstrated inhibition only in HDAC1. The in silico analysis showed that HDAC1 regulates a load of genes involved in the carcinogenic process, being the heights interaction scores related to the protein EP300 (histone deacetylase), but it was also correlated to TP53, RB1 and RBL proteins, widely involved in the carcinogenic process. HDAC 2 demonstrated a high score interaction with all the correlated targets, such as the DNMT1 (DNA methyltransferases), CDH4 and TP53. Both compounds presented inhibitory activity for HDAC1 e HDAC2, like the commercial compound, in a time-dependent way. HDAC1 and HDAC2 targets participate in the regulation of genes related to the carcinogenesis process, being an important molecular target in anticancer therapy.