Study of the effect of ACYP2 single nucleotide polymorphisms rs843711 and rs843706 in Egyptian patients with hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is a multifactorial disease with both genetic and environmental factors contributing to its pathogenesis. ACYP2 is a gene that is related to cell differentiation, apoptosis and prevention of malignant tumors. The ACYP2 gene also affects telomere length. The aim of this study was to evaluate the association between ACYP2 single nucleotide polymorphisms (SNPs) (rs843711), and (rs843706) and incidence of HCC in Egyptian HCC patients. The study included 30 patients with HCC and 30 normal controls. Detection of ACYP2 gene SNPs rs843711, and rs843706 in all study participants was done using real time polymerase chain reaction (RT-PCR). The results showed that all participants including HCC patients and controls carried the heterozygous CA (100%) of the rs843706 SNP (p> 0.05). As for the rs843711, 3.3% of HCC patients had the homozygous TT genotype, 46.7% had the heterozygous CT genotype and 50% had the wild CC genotype, while in the control group, 60% had the heterozygous CT genotype and 40% had the wild CC genotype with no significant difference between both groups (p>0.05). We concluded that there was no association between SNPs ACYP2 rs843706 and rs843711 and occurrence of HCC.

Amyloid Aggregation Is Potently Slowed Down by Osmolytes Due to Compaction of Partially Folded State.

Amyloid aggregation is a key process in amyloidoses and neurodegenerative diseases. Hydrophobicity is one of the major driving forces for this type of aggregation, as an increase in hydrophobicity generally correlates with aggregation susceptibility and rate. However, most experimental systems in vitro and prediction tools in silico neglect the contribution of protective osmolytes present in the cellular environment. Here, we assessed the role of hydrophobic mutations in amyloid aggregation in the presence of osmolytes. To achieve this goal, we used the model protein human muscle acylphosphatase (mAcP) and mutations to leucine that increased its hydrophobicity without affecting its thermodynamic stability. Osmolytes significantly slowed down the aggregation kinetics of the hydrophobic mutants, with an effect larger than that observed on the wild-type protein. The effect increased as the mutation site was closer to the middle of the protein sequence. We propose that the preferential exclusion of osmolytes from mutation-introduced hydrophobic side-chains quenches the aggregation potential of the ensemble of partially unfolded states of the protein by inducing its compaction and inhibiting its self-assembly with other proteins. Our results suggest that including the effect of the cellular environment in experimental setups and predictive softwares, for both mechanistic studies and drug design, is essential in order to obtain a more complete combination of the driving forces of amyloid aggregation.