title: DNA demethylation of vascular endothelial growth factor-C is associated with gene expression and its possible involvement of lymphangiogenesis in gastric cancer.
abstract: Previous studies have indicated that lymphangiogenesis in solid tumors is associated with lymphatic metastasis. Overexpression of Vascular endothelial growth factor (VEGF)-C plays a major role in lymphangiogenesis in cancers. In the present study, DNA methylation and expression of the VEGF-C gene was investigated in gastric cancer (GC). Four GC cell lines (MKN-45, MKN-74, HSC-39 and HSC-43) showed no expression of VEGF-C, and the VEGF-C gene was found to be methylated in these cells. In contrast, 7 GC cell lines (MKN-1, MKN-7, MKN-28, TMK-1, KATO-III, SH101-P4 and HSC-44PE) expressed VEGF-C, and the VEGF-C gene was found to be unmethylated in these cell lines. In addition, expression of VEGF-C mRNA was retrieved by treatment with a demethylating agent, Aza-2'-deoxycytidine. In GC tissue samples, bisulfite DNA sequencing analysis revealed that VEGF-C was not methylated in 9 (29.0%) of 31 GC samples, whereas demethylation was not observed in corresponding non-neoplastic mucosa samples. Overexpression of VEGF-C mRNA was observed in 16 (51.6%) of 31 GC samples by quantitative reverse transcription-polymerase chain reaction. Of the 9 GC cases with VEGF-C demethylation, 8 (88.9%) overexpressed VEGF-C. In contrast, of the 22 GC cases without VEGF-C demethylation, 8 (36.4%) overexpressed VEGF-C (p = 0.0155). Furthermore, lymphatic vessel density determined by immunostaining of podoplanin in GC tissues was associated with overexpression of VEGF-C (p < 0.0001). These results suggest that demethylation and activation of the VEGF-C gene is likely involved in lymphangiogenesis in GC.
authors.affiliation: Department of Molecular Pathology, Hiroshima University Graduate School of Biomedical Sciences, Hiroshima, Japan.
authors.forename: Shunji
authors.initials: S
authors.lastname: Matsumura
authors.forename: Naohide
authors.initials: N
authors.lastname: Oue
authors.forename: Yoshitsugu
authors.initials: Y
authors.lastname: Mitani
authors.forename: Yasuhiko
authors.initials: Y
authors.lastname: Kitadai
authors.forename: Wataru
authors.initials: W
authors.lastname: Yasui
mesh_terms: D000230:Adenocarcinoma / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor; D019175:DNA Methylation; D004273:DNA, Neoplasm / Q000235:genetics / Q000378:metabolism; D005260:Female; D015972:Gene Expression Regulation, Neoplastic / Q000502:physiology*; D006801:Humans; D042583:Lymphangiogenesis / Q000235:genetics*; D042601:Lymphatic Vessels / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011379:Prognosis; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012334:RNA, Neoplasm / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013274:Stomach Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D014407:Tumor Cells, Cultured; D042461:Vascular Endothelial Growth Factor A / Q000235:genetics / Q000378:metabolism; D042561:Vascular Endothelial Growth Factor B / Q000235:genetics / Q000378:metabolism; D042582:Vascular Endothelial Growth Factor C / Q000235:genetics* / Q000378:metabolism; D042643:Vascular Endothelial Growth Factor D / Q000235:genetics / Q000378:metabolism
chemical_list: D014408:Biomarkers, Tumor; D004273:DNA, Neoplasm; D012333:RNA, Messenger; D012334:RNA, Neoplasm; C467484:VEGFA protein, human; C467485:VEGFB protein, human; C467486:VEGFC protein, human; D042461:Vascular Endothelial Growth Factor A; D042561:Vascular Endothelial Growth Factor B; D042582:Vascular Endothelial Growth Factor C; D042643:Vascular Endothelial Growth Factor D