title: The NMDA receptor NR2A subunit regulates proliferation of MKN45 human gastric cancer cells.
abstract: The present study investigated proliferation of MKN28 and MKN45 human gastric cancer cells regulated by the N-methyl-d-aspartate (NMDA) receptor subunit. The NMDA receptor antagonist dl-2-amino-5-phosphonovaleric acid (AP5) inhibited proliferation of MKN45 cells, but not MKN28 cells. Of the NMDA subunits such as NR1, NR2 (2A, 2B, 2C, and 2D), and NR3 (3A and 3B), all the NMDA subunit mRNAs except for the NR2B subunit mRNA were expressed in both MKN28 and MKN45 cells. MKN45 cells were characterized by higher expression of the NR2A subunit mRNA and lower expression of the NR1 subunit mRNA, but MKN28 otherwise by higher expression of the NR1 subunit mRNA and lower expression of the NR2A subunit mRNA. MKN45 cell proliferation was also inhibited by silencing the NR2A subunit-targeted gene. For MKN45 cells, AP5 or knocking-down the NR2A subunit increased the proportion of cells in the G(1) phase of cell cycling and decreased the proportion in the S/G(2) phase. The results of the present study, thus, suggest that blockage of NMDA receptors including the NR2A subunit suppresses MKN45 cell proliferation due to cell cycle arrest at the G(1) phase; in other words, the NR2A subunit promotes MKN45 cell proliferation by accelerating cell cycling.
authors.affiliation: Department of Physiology, Hyogo College of Medicine, 1-1 Mukogawa-cho, Nishinomiya 663-8501, Japan.
authors.forename: Kanako
authors.initials: K
authors.lastname: Watanabe
authors.forename: Takeshi
authors.initials: T
authors.lastname: Kanno
authors.forename: Tadayuki
authors.initials: T
authors.lastname: Oshima
authors.forename: Hiroto
authors.initials: H
authors.lastname: Miwa
authors.forename: Chikara
authors.initials: C
authors.lastname: Tashiro
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Nishizaki
mesh_terms: D045744:Cell Line, Tumor; D049109:Cell Proliferation; D002470:Cell Survival; D006801:Humans; D016194:Receptors, N-Methyl-D-Aspartate / Q000378:metabolism*; D013274:Stomach Neoplasms / Q000378:metabolism* / Q000473:pathology*
chemical_list: C120997:NR2A NMDA receptor; D016194:Receptors, N-Methyl-D-Aspartate