Grb7-derived calmodulin-binding peptides inhibit proliferation, migration and invasiveness of tumor cells while they enhance attachment to the substrate

Abstract

The growth factor receptor bound protein 7 (Grb7) is a Ca 2þ -dependent calmodulin (CaM)-binding adaptor protein implicated, among other functions, in cell proliferation, migration and tumor-associated angiogenesis. The goal of this study was to determine whether a peptide based on the CaM binding site of Grb7 disrupts cellular processes, relevant for the malignancy of tumor cells, in which this adaptor protein is implicated. We designed synthetic myristoylated and non-myristoylated peptides corresponding to the CaM-binding domain of human Grb7 with the sequence 243 RKLWKRFFCFLRRS 256 and a variant peptide with the mutated sequence RKLERFFCFLRRE (W246E-ΔK247-S256E). The two non-myristoylated peptides bind dansyl-CaM with higher efficiency in the presence than in the absence of Ca 2þ and they enter into the cell, as tested with 5(6)-carboxytetramethylrhodamine (TAMRA)-labeled peptides. The myristoylated and non-myristoylated peptides inhibit the proliferation, migration and invasiveness of A431 tumor cells while they enhance their adhesion to the substrate. The myristoylated peptides have stronger inhibitory effect than the non-myristoylated counterparts, in agreement with their expected higher cell-permeant capacity. The myristoylated and non-myristoylated W246E-ΔK247-S256E mutant peptide has a lesser inhibitory effect on cell proliferation as compared to the wild-type peptide. We also demonstrated that the myristoylated peptides were more efficient than the CaM antagonist N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide (W-7) inhibiting cell migration and equally efficient inhibiting cell proliferation.

The role of the calmodulin‐binding and calmodulin‐like domains of the epidermal growth factor receptor in tyrosine kinase activation

“…Published works using cell‐permeable inhibitory peptides against the CaM‐BD of the EGFR have shown, not only in cultured cells but also and most impressively in animal models, its inhibitory action, a proof of concept of its potential therapeutic effects (Boran et al, 2012; Hart et al, 2013; Villalobo et al, 2013). Moreover, a peptide corresponding to the CaM‐BD of the adaptor protein growth factor receptor bound protein 7 with CaM sequestering capacity also inhibited tumor cells proliferation and its migratory/invasive capacity (Alcalde et al, 2020).…”

La proteína 7 unida al receptor del factor de crecimiento (GRB7) en cáncer de mama

“…28 La región central contiene tres dominios: RA (asociado a Ras) por lo cual se cree que GRB7 interactúa con las GTPAsas de la superfamilia Ras y de esta forma regula la progresión del cáncer, un dominio de homología a pleckstrina (PH) y el dominio BPS (entre PH y SH2) el cual interactúa principalmente con el receptor de insulina activado en el dominio SH2. 18 Consistente con sus dominios estructurales, GRB7 interactúa con una gran variedad de residuos fosfo-tirosina en receptores tirosina quinasa como EGFR (receptor del factor de crecimiento epidérmico) 29 , HER-2,HER3, HER4, PDGFR (receptor de factor de crecimiento derivado de plaqueta), EphB1 (receptor 1 DE efrina tipo B), c-Kit y con tirosina quinasas no receptoras como la quinasa de adhesión focal (FAK) y la proteína quinasa B (Akt); todos ellos conocidos como "socios de unión" (más de 20) 17,30 (figura 1).…”

GRB7 plays a promoting role in the progression of gastric cancer

“…Growth factor receptor bound protein 7 (GRB7) is a modular Src homology domain 2 (SH2)-containing adaptor protein, which belongs to the Grb7 adaptor protein family [ 9 , 10 ]. Moreover, GRB7 is composed of a proline rich N-terminal domain, a Ras-associating domain, a plekstrin homology (PH) domain, a C-terminal SH2 domain and a BPS domain [ 11 ].…”