Claudin-1 Contributes to Gastrointestinal Stromal Tumors (GIST) Resistance to Imatinib Mesylate (IM) via Regulation of FGFR-Signaling.

ABSTRACT: We previously demonstrated that the activation of FGFR signaling in GIST may be a mechanism of GIST resistance to imatinib mesylate (IM). We show here that IM-resistant GIST cells lacking secondary KIT mutations overexpress claudin-1 on both transcriptional and translational levels. In contrast, a knockdown of CLDN1 or inhibition of its activity by PDS-0330 effectively restored GIST's sensitivity to IM both in vitro and in vivo. This was evidenced by the increased expression of apoptotic markers (e.g., cleaved PARP and caspase-3) and the decreased proliferation rate of IM-resistant GIST T-1R cells treated with a combination of IM and PDS-0330 (or siRNA CLDN1). In concordance with these findings, a significant synergy was observed between IM and PDS-0330 in GIST T-1R ce

SUBMITTER: Boichuk S 

PROVIDER: S-EPMC12428531 | biostudies-literature | 2025 Aug

REPOSITORIES: biostudies-literature