Identification of selective inhibitors for diffuse-type gastric cancer cells by screening of annotated compounds in E-cadherin/p53 double conditional knockout mice

ABSTRACT: Diffuse-type gastric cancer (DGC) exhibits rapid disease progression and a poor patient prognosis. We have previously established an E-cadherin/p53 double conditional knockout (DCKO) mouse line as the first genetically engineered one, which morphologically and molecularly recapitulates human DGC. In this study, we explored low-molecular-weight drugs selectively eliminating mouse DGC cells, and then validated their inhibitory effects on human DGC. We first derived mouse gastric cancer (GC) cell lines from DGC of the DCKO mice, which notably demonstrated enhanced tumorigenic activity in immunodeficient mice and acquired tolerance to cytotoxic anti-cancer agents. We next performed a synthetic lethal screening of 1535 annotated chemical compounds by using them. Comparing cell viability of the E-cadherin/p53-deficient GC and p53-deficient gastric epithelial (GE) cells under treatment with the compound library, we identified 27 candidates with specific toxicity to the GC cell lines. The most potent drug mestranol, an estrogen derivative, and other estrogen receptor modulators induced apoptotic events preceded by DNA damage only in the GC cell lines, but not in the GE. Moreover, mestranol could significantly suppress tumor growth of the GC cells subcutaneously transplanted into nude mice, consistent with longer survival time in the female DCKO mice than in the male. As expected, human E-cadherin-mutant and -low gastric cancer cells showed higher susceptibility to estrogen drugs in contrast to E-cadherin-intact ones in vitro and in vivo. These findings may lead to the development of novel therapeutic strategies targeting E-cadherin-deficient DGC.

ORGANISM(S): Mus musculus

PROVIDER: GSE102297 | GEO | 2018/07/31

REPOSITORIES: GEO