Prostaglandin E2 and its receptor EP2 trigger signaling that contributes to YAP-mediated cell competition.

Erika Ishihara,Yukihiko Sugimoto,Shuji Terai,Yasuyuki Fujita,Hiroyuki Kagechika,Akira Suzuki,Toshiaki Okuno,Kenya Kamimura,Hiroshi Nishina,Satoshi Kofuji,Takehiko Yokomizo,Mari Ishigami‐Yuasa,Yuya Nagaoka

doi:10.1111/gtc.12750

Abstract

Cell competition is a biological process by which unfit cells are eliminated from “cell society.” We previously showed that cultured mammalian epithelial Madin‐Darby canine kidney (MDCK) cells expressing constitutively active YAP were eliminated by apical extrusion when surrounded by “normal” MDCK cells. However, the molecular mechanism underlying the elimination of active YAP‐expressing cells was unknown. Here, we used high‐throughput chemical compound screening to identify cyclooxygenase‐2 (COX‐2) as a key molecule triggering cell competition. Our work shows that COX‐2‐mediated PGE2 secretion engages its receptor EP2 on abnormal and nearby normal cells. This engagement of EP2 triggers downstream signaling via an adenylyl cyclase‐cyclic AMP‐PKA pathway that, in the presence of active YAP, induces E‐cadherin internalization leading to apical extrusion. Thus, COX‐2‐induced PGE2 appears a warning signal to both abnormal and surrounding normal cells to drive cell competition.

Highlights

To investigate whether the cell aggregation we observed was correlated with apical extrusion, we examined the effects of various apical extrusion inhibitors, including LY294002, an inhibitor of phosphoinositide-3-kinase (PI3K); rapamycin, an inhibitor of mammalian target of rapamycin; and PF-4708671, an inhibitor of p70S6 kinase (p70S6K), on cell aggregation after cell competition
To investigate whether COX-2 was involved in the apical extrusion of Ras (G12V) or v-Src cells, we evaluated the effects of NS398 on cocultures of these cells with normal Madin-Darby canine kidney (MDCK) cells and compared them with Yes-associated protein (YAP)
(b) Cells were treated for 16 hr with Dox plus butaprost (EP2 agonist, 10 μM). (c) Cells were treated for 24 hr with Dox and NS398 (50 μM) plus butaprost (10 μM), U-46619 (TP agonist, 100 nM), Fluprostenol (FP agonist, 10 μM), sulprostone (EP1/3 agonist, 10 μM), BW-245C (DP agonist, 10 μM) or Cicaprost (IP agonist, 10 μM). (d) Cells were treated for 24 hr with Dox and NS398 (50 μM) plus PGE2 (1 μM or 5 μM)

Summary

Introduction

These results indicate that COX-2 is essential for the apical extrusion of the YAP (5SA) cells cultured in competition with normal To investigate whether COX-2 was involved in the apical extrusion of Ras (G12V) or v-Src cells, we evaluated the effects of NS398 on cocultures of these cells with normal MDCK cells and compared them with YAP In our standard cell competition assay, conducted in culture medium containing fetal bovine serum (FBS), the percentage of YAP (5SA) cells that undergoes apical extrusion in the presence of normal MDCK cells but in the absence of Dox is typically 10%.

Results

Conclusion