E-cadherin-deficient cells have synthetic lethal vulnerabilities in plasma membrane organisation, dynamics and function

Abstract

Background The E-cadherin gene (CDH1) is frequently mutated in diffuse gastric cancer and lobular breast cancer, and germline mutations predispose to the cancer syndrome Hereditary Diffuse Gastric Cancer. We are taking a synthetic lethal approach to identify druggable vulnerabilities in CDH1-mutant cancers. Methods Density distributions of cell viability data from a genome-wide RNAi screen of isogenic MCF10A and MCF10A-CDH1 −/− cells were used to identify protein classes affected by CDH1 mutation. The synthetic lethal relationship between selected protein classes and E-cadherin was characterised by drug sensitivity assays in both the isogenic breast MCF10A cells and CDH1-isogenic gastric NCI-N87. Endocytosis efficiency was quantified using cholera toxin B uptake. Pathway metagene expression of 415 TCGA gastric tumours was statistically correlated with CDH1 expression. Results MCF10A-CDH1 −/− cells showed significantly altered sensitivity to RNAi inhibition of groups of genes including the PI3K/AKT pathway, GPCRs, ion channels, proteosomal subunit proteins and ubiquitinylation enzymes. Both MCF10A-CDH1 −/− and NCI-N87-CDH1 −/− cells were more sensitive than wild-type cells to compounds that disrupted plasma membrane composition and trafficking, but showed contrasting sensitivities to inhibitors of actin polymerisation and the chloride channel inhibitor NS3728. The MCF10A-CDH1 −/− cell lines showed reduced capacity to endocytose cholera toxin B. Pathway metagene analysis identified 20 Reactome pathways that were potentially synthetic lethal in tumours. Genes involved in GPCR signalling, vesicle transport and the metabolism of PI3K and membrane lipids were strongly represented amongst the candidate synthetic lethal genes. Conclusions E-cadherin loss leads to disturbances in receptor signalling and plasma membrane trafficking and organisation, creating druggable vulnerabilities.

Extracellular Vesicles with Possible Roles in Gut Intestinal Tract Homeostasis and IBD

“…The toxicity of HtrA proteins and their orthologues are nonnegligible in both prokaryotes and eukaryotes [58]. The function of E-cadherin to establish and maintain epithelial integrity has been discussed in many studies [59,60]. Deleting the HtrA protein in C. jejuni can alter Ecadherin shedding [61].…”

Hereditary Gastric and Breast Cancer Syndromes Related to CDH1 Germline Mutation: A Multidisciplinary Clinical Review

“…E-cadherin-null cells have numerous adaptations that affect the cortical actin cytoskeleton. These changes appear to undermine the efficiency of the plasma membrane deformation processes, establishing numerous druggable vulnerabilities [44], yet to be explored for the chemoprevention of DGC and LBC [45].…”

CDH1 Gene and Hereditary Diffuse Gastric Cancer Syndrome: Molecular and Histological Alterations and Implications for Diagnosis And Treatment

“…The cytoplasmic domain of E-cadherin interacts with β-, p120-, and α-catenins anchored to the actin cytoskeleton (Blaschuk et al, 1990). The interaction with actin is required for membrane deformation processes such as endocytosis, exocytosis, autophagy and receptor/channel recycling, and is involved in cell membrane maintenance, tension, ion channel activity among others (Gumbiner, 1996; Godwin et al, 2018). E-cadherin deficiency undermines the efficiency of these different processes and potentially cell survivability (Godwin et al, 2018).…”

“…The interaction with actin is required for membrane deformation processes such as endocytosis, exocytosis, autophagy and receptor/channel recycling, and is involved in cell membrane maintenance, tension, ion channel activity among others (Gumbiner, 1996; Godwin et al, 2018). E-cadherin deficiency undermines the efficiency of these different processes and potentially cell survivability (Godwin et al, 2018). E-cadherin plays an important role in blastomere adhesion during development, which polarizes the cells and allows differentiation to occur (Fleming et al, 1992).…”