RESUMEN
Colorectal cancer (CRC) is the third most common type of cancer and the fourth leading cause of cancer related deaths worldwide. The Histone Deacetylase 8 (HDAC8) gene is a gene with unique features which can be used as a potential target for drug design. The LHX1 transcription factor is an important transcription factor for this gene. The aim of this study was to investigate the effect of sodium butyrate (NaB) as a histone deacetylase inhibitor (HDACi) on the expression of the HDAC8 gene in the colorectal cancer cell line, and the molecular docking of the LHX1 transcription factor with NaB. For this purpose, HCT-116 and HT-29 cell lines were treated with different concentrations of NaB (6.25 mM to 150 mM) at 24, 48 and 72 hours. Subsequently, RNA was extracted from the treated and untreated cells and cDNA was synthesized. Quantitative Real-Time-PCR was done to investigate the mRNA expression of HDAC8. Molecular docking was also performed to investigate the interaction between NaB and LHX1. Based on Real-time-PCR results, the concentration of 150 mM of NaB after 24 hours in HT-29 and HCT-116 cell lines caused a significant reduction in mRNA expression of HDAC8 (P<0.05). After 48 hours of treatment, there was a significant decrease in the mRNA expression of HDAC8 at all concentrations (P<0.05). The docking results showed that LHX1 and NaB interacted best at the lowest energy levels. Our results also showed that NaB bonded strongly to LHX1. In addition, our results demonstrated that NaB bound to the LHX1 transcription factor and inhibited the function of this factor and consequently decreased the transcription from the HDAC8 gene which resulted in cell death. Future studies are needed to assess the likely molecular mechanisms of NaB action on gene expression.
RESUMEN
BACKGROUND: LHX1 is an important transcription factor for the HDAC8 gene. The aim of this study was to investigate the effect of Sodium Butyrate (SB), as a histone deacetylase inhibitor, on the expression of LHX1 gene in colorectal cancer cell lines. METHODS: HT-29 and HCT-116 cell lines were treated with 6.25 to 200 mM concentrations of SB at 24, 48, and 72 hr. The cytotoxicity effect on cell viability was evaluated by MTT assay. The 50% Inhibiting Concentration (IC50) was determined graphically. Quantitative real-time PCR was performed to investigate the LHX1 mRNA expression level. RESULTS: Our study revealed that SB inhibited the proliferation of these cell lines in a concentration and time-dependent manner. The IC50 values for HT-29 cell line were 65, 18.6, and 9.2 mM after 24, 48, and 72 hr of treatment, respectively. The IC50 values for HCT-116 cell line were 35.5, 9.6, and 10 mM after 24, 48, and 72 hr of treatment, respectively. Furthermore, real-time PCR findings demonstrated that the LHX1 mRNA expression in treated HT-29 cell line significantly increased in comparison with untreated cells (p<0.05). However, in treated HCT-116 cell line, SB led to a significant decrease in the level of LHX1 mRNA (p<0.05), as compared to untreated cells. CONCLUSION: In this study, different effects of SB on LHX1 mRNA expression level were revealed in two distinct human colorectal cancer cell lines.