Abstract 3619: EP4 promoted cell migration via mitochondrial biogenesis in oral cancer cells

• Published in: Cancer research (Chicago, Ill.) Ill.), 2023-04, Vol.83 (7_Supplement), p.3619-3619
• Main Authors: Ishikawa, Soichiro, Umemura, Masanari, Nakakaji, Rina, Nagasako, Akane, Nagao, Kagemichi, Mizuno, Yuto, Suzuki, Fumina, Osawa, Kohei, Kioi, Mitomu, Mitsudo, Kenji, Ishikawa, Yoshihiro
• Format: Article
• Language: English
• ISSN: 1538-7445; 1538-7445
• DOI: 10.1158/1538-7445.AM2023-3619

Introduction: Lymph node metastasis caused by migration of oral cancer cells is an important prognostic factor. We previously reported that EP4, a prostaglandin E2 (PGE2) receptor, regulates the cell migration in oral cancer cells via Ca2+ signaling. However, how Ca2+ signaling regulates cell migration remains unclear. The intracellular Ca2+ regulates a variety of signaling pathways, either directly or by forming complexes with proteins such as calmodulin (CaM), and then phosphorylates calcium/calmodulin-dependent protein kinase kinase 2 (CaMKK2). Furthermore, Ca2+ signaling is directly or indirectly involved in cancer cell proliferation and migration. Therefore, we hypothesized that EP4 regulates the cell migration via CaMKK2 and its downstream signaling in oral cancer. Materials and Methods: Human gingival fibroblasts, HGnF and Human tongue squamous cell carcinoma cell lines, HSC-3 were used. EP4 agonist (ONO-AE1-437) and CaMKK2 inhibitor (STO-609) were used. HSC-3 cells were transduced with CaMKK2 shRNA, and scramble control shRNA using lentivirus. The protein expressions were evaluated by western blotting. The intracellular calcium concentrations were measured using Fura-2, the Fluorescent Ca2+ Indicator. The cell migration ability was evaluated by scratch assay. Immunocytochemistry was performed to evaluate the lamellipodium. The mRNA transcriptions of the mitochondrial associated genes were evaluated by real-time qPCR. The intracellular adenosine triphosphate (ATP) production and the reactive oxygen species (ROS) production were also evaluated by luciferase activity assay and DCFH-DA staining. Results: EP4 protein expression of HSC-3 cells was higher than that of HGnF cells (n=4, p