In order to identify novel targets for the molecular
therapy of
gastric cancer (GC), we investigated the
mRNA and
protein expression of frizzled-2 (Fz2), a Wnt signaling pathway receptor.
Reverse-transcriptase polymerase chain reaction (PCR) amplification was utilized to determine the expression patterns of Fz genes in normal stomach and in the GC cell lines MKN45 and MKN74. Immunostaining was performed on surgical specimens of GC using an antibody against Fz2. The 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2- (4-sulfophenyl)-2H-tetrazolium inner
salt (MTS) assay was performed on MKN45 cells and MKN74 cells transfected with Fz2 short-hairpin (sh)
RNA. Cell motility was analyzed by scratch assay following Fz2
shRNA. Real-time quantitative PCR was performed to analyze the expression levels of
cyclin D1 and matrix
metallopeptidase 9 (MMP-9). Fz1, 3, 6 and 8 were expressed in normal stomach, and in MKN45 and MKN74 cells. Fz2 was expressed in normal stomach and in MKN45, but not in MKN74 cells. Well-differentiated GC tissue was weakly positive for Fz2 in cell membranes. Fz2 was positive in both the cell membrane and cytoplasm of GC tissues of moderately differentiated and poorly differentiated
adenocarcinoma. Signet ring cells were positive for cytoplasmic Fz2. Proliferation of MKN45 and MKN74 cells was suppressed by Fz2
shRNA, and a scratch assay demonstrated that Fz2
shRNA suppressed also MKN45 and MKN74 cell motility. Furthermore, Fz2
shRNA application led to downregulated
mRNA expression of both
cyclin D1 and MMP-9. Fz2, 3, 6 and 8 were expressed in normal stomach, and in MKN45 and MKN74 GC cells. Fz2
shRNA suppressed cell proliferation and motility of MKN45 and MKN74 cells, and downregulated
cyclin D1 and MMP-9 expression in these GC cell lines.