Impact of coding and non-coding SNPs in the FZD8 gene on structural and functional alterations associated with tumorigenesis: A multi-faceted computational approach.

FZD8, a GPCR, is involved in various physiological processes, such as cell differentiation, bone growth and stem cell regulation, by binding to various Wnt ligands. Though FZD receptors have low mutation rates in cancer, aberrant Wnt or FZD expression leads to deregulated Wnt/FZD signaling pathways that may result in tumorigenesis. The structural and functional effects of most of the coding and non-coding SNPs of human FZD8 gene are yet to explore. In the present study, we analyzed 450, 109, and 390 SNPs in the CDS, 3'UTR, and 5'UTR of the FZD8 gene, respectively, using advanced state-of-the-art bioinformatics tools to explore their structural and functional consequences in tumorigenesis. We identified 10 highly deleterious nsSNPs among which 6 nsSNPs were located within the Wnt1 binding CRD region of FZD8. Additionally, these nsSNPs were also predicted to affect post-translational modifications in FZD8. The highly deleterious variant P120Q, causes significant structural change in secondary structure of FZD8 mRNA. Structure based stability prediction revealed 4 destabilizing variants among 6 highly deleterious variants. Wnt1 binds most strongly with FZD8-CRD among other FZD-CRDs. MD simulation analyses revealed that the binding energies of the mutated complexes were less stabilizing compared to the wild-type Wnt1-FZD8-CRD complex, with the P74L and A119E complexes predicted to be the most destabilizing. SNPs, rs1408188233 (34.T > C) in 3'UTR and rs1588706985 in 5'UTR may lead to AGO2 mediated and E2F6 mediated silencing of the FZD8 gene, respectively, whereas nsSNPs-rs1322411573 and rs1410965895 in the CDS may abolish miRNA-mediated gene silencing. Differential expression of FZD8 was observed across various normal, tumor, and metastatic tissues, and its deregulation was associated with reduced survival outcomes in patients with different types of cancer. Additionally, several biomarkers involving FZD8 mutations have been identified in patients with gastric cancer, multiple myeloma, and uterine cancer. Furthermore, these computationally prioritized high risk SNPs of FZD8 can be investigated in population based genetic studies and may serve as potential targets for future drug development against FZD8-associated diseases.