MicroRNA Assisted Gene Regulation in Colorectal Cancer
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
Authors: Fadaka, Adewale O.; Pretorius, Ashley; Klein, Ashwil
Abstract
Colorectal cancer (CRC) is the second-leading cause of cancer death and a major public health problem. Nearly 80% CRC cases are diagnosed after the disease have metastasized and are often too advanced for treatment. Small non-coding RNA guides argonaute protein to their specific target for regulation as the sole of RNA induced silencing complex for gene silencing. These non-coding RNA for example microRNA, are thought to play a key role in affecting the efficiency of gene regulation in cancer, especially CRC. Understanding the mechanism at the molecular level could lead to improved diagnosis, treatment, and management decisions for CRC. The study aimed to predict the molecular mechanism of gene regulation based microRNA-mRNA duplex as a lead in the silencing mechanism. Five candidate microRNAs were identified through the in silico approach. The MicroRNA target prediction and subsequent correlation, and prioritization were performed using miRTarBase, gbCRC and CoReCG, and DAVID databases respectively. Protein selection and preparation were carried out using PDB and Schrodinger suits. The molecular docking analysis was performed using PATCHDOCK webserver and visualized by discovery studio visualizer. The results of the study reveal that the candidate microRNAs have strong binding affinity towards their targets suggesting a crucial factor in the silencing mechanism. Furthermore, the molecular docking of the receptor to both the microRNA and microRNA-mRNA duplex were analyzed computationally to understand their interaction at the molecular level. Conclusively, the study provides an explanation for understanding the microRNAs-based gene regulation (silencing mechanism) in CRC.
Val16Ala-SOD2 polymorphism modulates hypothalamic-pituitary-adrenal axis molecules and BDNF levels in healthy adults under no psychological stress
GENETICS AND MOLECULAR RESEARCH
Authors: da Cruz Jung, I. E.; Duarte, T.; da Cruz, I. B. M.; Turra, B. O.; Chitolina, B.; Motta, J. R.; Montano, M. A. E.; Azzolin, V. F.; Ribeiro, E. E.; Duarte, M. M. M. F.; Barbisan, F.
Abstract
Chronic psychological stress alters the hypothalamic-pituitary-adrenal axis (HPA-axis), triggering chronic oxidative-inflammatory states that are associated with physical and psychiatric conditions. However, it is not clear if basal oxidative-inflammatory states triggered by genetic variation affect the HPA-axis by altering cortisol, adrenocorticotropic hormone (ACTH) and dehydroepiandrosterone sulfate (DHEA-S) levels. Humans have a single nucleotide polymorphism (SNP) found in manganese-dependent superoxide dismutase (Val16Ala-SOD2, rs4880), which has two alleles (V and A) which affect the basal efficacy of SOD2 antioxidant enzyme in the mitochondria. The VV-genotype, which presents low SOD2-efficacy, has been associated with chronic inflammatory states, as well as higher risk of depression and self-reported psychological stress. Therefore, basal oxidative imbalance could have some influence on modulation of HPA-axis physiology. We tested this hypothesis comparing morning blood levels of cortisol, ACTH and DHEA-S and other biochemical markers in 90 healthy adult university students previously genotyped for the SOD2-SNP (30 volunteers for each genotype, 26.5 +/- 8.7 years old). Only volunteers who self-reported no perception of psychological stress were included in the study. The VV group had higher morning cortisol and ACTH, and lower DHEA-S and brain-derived neurotrophic factor (BDNF) than A-allele subjects. These results indicate some influence of S-imbalance on modulation of this molecule. Therefore, we suggest that genetically controlled pro-oxidative and inflammatory states could modulate physiological markers for stress and neurogenesis.