Nonsynonymous mutations in VEGF receptor binding domain alter the efficacy of bevacizumab treatment.

Vascular endothelial growth factor (VEGF) mediated angiogenesis is crucial for tumor progression. Isoforms of VEGF bind to different VEGF receptors (VEGFRs) to initiate angiogenesis specific cellular signaling. Inhibitors that target both the receptors and ligands are in clinical use to impede angiogenesis. Bevacizumab, a monoclonal antibody (mAb) approved by the Food and Drug Administration (FDA), binds in the VEGF receptor binding domain (RBD) of all soluble isoforms of VEGF and inhibits the VEGF-VEGFR interaction. Bevacizumab is also used in combination with other chemotherapeutic agents for a better therapeutic outcome. Understanding the intricate polymorphic character of VEGFA gene and the influence of missense or nonsynonymous mutations in the form of nonsynonymous polymorphisms (nsSNPs) on RBD of VEGF may aid in increasing the efficacy of this drug. This study has identified 18 potential nsSNPs in VEGFA gene that affect the VEGF RBD structure and alter its binding pattern to bevacizumab. The mutated RBDs, modeled using trRosetta, in addition to the changed pattern of secondary structure, post translational modification and stability compared to the wild type, have shown contrasting binding affinity and molecular interaction pattern with bevacizumab. Molecular docking analysis by ClusPro and visualization using PyMol and PDBsum tools have detected 17 nsSNPs with decreased binding affinity to bevacizumab and therefore may impact the treatment efficacy. Whereas VEGF RBD expressed due to rs1267535717 (R229H) nsSNP of VEGFA has increased affinity to the mAb. This study suggests that genetic characterization of VEGFA before bevacizumab mediated cancer treatment is essential in predicting the appropriate efficacy of the drug, as the treatment efficiency may vary at individual level.

Non-synonymous Single Nucleotide Polymorphisms in Human ACE2 Gene May Affect the Infectivity of SARS-CoV-2 Omicron Subvariants.

BACKGROUND: The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes the coronavirus disease 2019 (COVID-19), which first appeared in December 2019. Angiotensin I converting enzyme 2 (ACE2) receptor, present on the host cells, interacts with the receptor binding domain (RBD) of spike (S) protein of SARS-CoV-2 and facilitates the viral entry into host cells. METHODS: Non-synonymous single nucleotide polymorphisms (nsSNPs) in the ACE2 gene may have an impact on the protein's stability and its function. The deleterious or harmful nsSNPs of the ACE2 gene that can change the strength as well as the pattern of interaction with the RBD of S protein were selected for this study. RESULTS: The ACE2:RBD interactions were analyzed by protein-protein docking study. The missense mutations A242V, R708W, G405E, D292N, Y633C, F308L, and G405E in ACE2 receptor were found to interact with RBD of Omicron subvariants with stronger binding affinity. Among the other selected nsSNPs of human ACE2 (hACE2), R768W, Y654S, F588S, R710C, R710C, A191P, and R710C were found to have lower binding affinity for RBD of Omicron subvariants. CONCLUSION: The findings of this study suggest that the nsSNPs present in the human ACE2 gene alter the structure and function of the protein and, consequently, the susceptibility to Omicron subvariants.