PepGAT, um peptídeo sintético derivado de uma quitinase, altera o perfil proteômico das células do câncer colorretal e perturba as vias envolvidas na sobrevivência do câncer

Abstract

PepGAT, a synthetic peptide that has shown antimicrobial activity in previous studies, has recently been shown to induce death in HCT-116 human colorectal cancer (CRC) cells and to have low toxicity in normal cells. Our study showed that PepGAT disrupts the pathways involved in cancer survival and potentiates the action of 5-Fluorouracil (5-FU) in CRC. To this end, an analysis of the protein profile in HCT-116 cells after treatment with PepGAT was carried out using UHPLC MS/MS and PatternLab V. Fluorescence assays were used to evaluate membrane integrity and reactive oxygen species (ROS), as well as analyses of cell viability, apoptosis, cell cycle and extracellular matrix invasion in the presence of 5-FU. The results revealed that PepGAT induces early accumulation of ROS and alterations in the protein profile of HCT-116 cells, where there was a decrease in the abundance of proteins involved in ROS metabolism and energy metabolism, cell cycle, DNA repair, migration, invasion, cancer aggressiveness and proteins involved in resistance to 5-FU. PepGAT induced earlier apoptosis in HCT-116 cells, cell cycle arrest and inhibited the migration of HCT-116 cells, decreasing 5- FU by 6 times compared to HCT-116 and reducing its toxicity to non-cancerous cells. In silico analysis showed a correlation between proteomic and TCGA data, revealing that 12 proteins accumulated down-regulated by PepGAT in HCT-116 cells are also higher in samples from CRC patients. These findings strongly suggest the multiple mechanisms of action exhibited by PepGAT against CRC cells and its potential to be studied alone or in combination with 5-FU to develop new studies against CRC and may develop new drugs against it; in addition to studying the proteins not only as biomarkers but also as possible therapeutic targets in CRC.