FGF18–FGFR2 signaling triggers the activation of c-Jun–YAP1 axis to promote carcinogenesis in a subgroup of gastric cancer patients and indicates translational potential

Abstract

Fibroblast growth factor receptor type 2 (FGFR2) has emerged as a key oncogenic factor that regulates gastric cancer (GC) progression, but the underlying mechanism of FGF–FGFR2 signaling pathway remains largely unknown. To identify the potential molecular mechanisms of the oncogenic FGFR2 in gastric carcinogenesis and convey a novel therapeutic strategy, we profiled the FGFR alterations and analyzed their clinical associations in TCGA and Hong Kong GC cohorts. We found that FGFR2 overexpression in GC cell lines and primary tumors predicted poor survival and was associated with advanced stages of GC. Functionally, growth abilities and cell cycle progression of GC were inhibited by inactivation of ERK–MAPK signal transduction after FGFR2 knockdown, while apoptosis was promoted. Meanwhile, the first-line anti-cancer drug sensitivity was enhanced. RNA-seq analysis further revealed that YAP1 signaling serves as a significant downstream modulator and mediates the oncogenic signaling of FGFR2. When stimulating FGFR2 by rhFGF18, we observed intensified F-actin, nuclear accumulation of YAP1, and overexpression of YAP1 targets, but these effects were attenuated by either FGFR2 depletion or AZD4547 administration. Additionally, the FGF18–FGFR2 signaling upregulated YAP1 expression through activating c-Jun, an effector of MAPK signaling. In our cohort, 28.94% of GC cases were characterized as FGFR2, c-Jun, and YAP1 co-positive and demonstrated worse clinical outcomes. Remarkably, we also found that co-targeting FGFR2 and YAP1 by AZD4547 and Verteporfin synergistically enhanced the antitumor effects in vitro and in vivo. In conclusion, we have identified the oncogenic FGF–FGFR2 regulates YAP1 signaling in GC. The findings also highlight the translational potential of FGFR2–c-Jun–YAP1 axis, which may serve as a prognostic biomarker and therapeutic target for GC.

The transcription factor RUNX2 fuels YAP1 signaling and gastric cancer tumorigenesis

“…26 YAP1, a crucial transcriptional coactivator in the Hippo signaling pathway, is involved in the initiation and development of several cancers, including GC. 27,28 In 2004, Professor Lian confirmed that the RUNX2-YAP complex is essential for bone homeostasis, osteoblast activity, and mesenchymal stem cell (MSC) fate determination. 29,30 YAP1 can cooperate with RUNX2 and is crucial for the anchorage-independent growth of cancer cells.…”

Linc00641 promotes the progression of gastric carcinoma by modulating the miR-429/Notch-1 axis

“…Several signaling pathways have been found to participate in gastric tumorigenesis. For example, FGF18-FGFR2 signaling induces the c-Jun-YAP1 axis and enhances gastric carcinogenesis [ 27 ]. The role of Notch-1 in gastric cancer has been characterized in recent years.…”

The dawn of precision medicine in diffuse-type gastric cancer

“…YAP1 is a downstream transcription coactivator of the Hippo signaling pathway, which acts not only as a prominent molecule for tumorigenesis, but also as an oncogenic driver in GC. 109 – 113 YAP1 plays a crucial role in CSC expansion and properties in various tumor types, including GC. 107 , 114 , 115 In fact, genetic knockdown of YAP1 has been found to suppress gastric CSC traits, tumorigenesis, and peritoneal metastasis in vitro and in vivo .…”