title: Lymphangiogenesis in tumor tissues and 5'-Nase, Flt-4, Flk-1 expressions.
abstract: OBJECTIVE
  To investigate lymphangiogenesis in tumor tissues and 5'-Nase, Flt-4, Flk-1 expressions.
  
  
  METHODS
  5'-Nase and Aplase expressions and the morphology of lymphatics in gastric carcinoma tissues were observed with enzyme histochemistry. Flt-4 and Flk-1 expression in gastric carcinoma and sarcoma tissues was studied by immunohistochemistry. CNE-2z cells were implanted into the subdermal layer of nude mice and hyaluronic acid was injected at the same sites. After 4 or 5 weeks, nasopharyngeal carcinoma (NPC) xenograft tissues were cut for immunohistochemistry and enzyme histochemistry, and lymphangiogenesis, 5'-Nase, Alpase, Flt-4 and Flk-1 expression in NPC tissues was studied. Hyaluronic acid contents in sera of the patients with NPC and mice with NPC xenografts were measured by radioimmunoassay.
  
  
  RESULTS
  There were a lot of lymphatics and solid strip-like tissues in gastric carcinoma and NPC xenograft treated with hyaluronic acid. The total number of lymphatics (26.9 +/- 14.2/HP) increased significantly in gastric carcinoma tissues. Flt-4 and Flk-1 positive expression was found in gastric carcinoma, sarcoma tissues and NPC xenograft. Most of the vessels with positive Flt-4 were lymphatics. Flk-1 expression was only found in the walls of blood vessels. Hyaluronic acid content (363.52 +/- 98.15 ng/ml) in sera of patients with NPC was higher than that of the patients with chronic nasopharyngeal inflammation (306.29 +/- 27.15 ng/ml), with a significant difference (P = 0.039). The hyaluronic acid content in sera of nude mice with NPC (2120.59 +/- 490.22 ng/ml) was markedly higher than that in normal mice (1588.99 +/- 502.12 ng/ml), with a significant difference between them (P = 0.007).
  
  
  CONCLUSIONS
  There are a lot of lymph capillaries with positive 5'-Nase in gastric carcinoma and NPC xenograft treated with hyaluronic acid. Flt-4 positive expression is shown in gastric carcinoma, sarcoma tissues and NPC xenografts. The results suggest there is lymphangiogenesis in these malignant tumor tissues. Hyaluronic acid contents in sera of patients with NPC and nude mice with NPC increase, which may promote the formation of lymphatics.
authors.affiliation: Department of Pathology, Guangdong Medical College, Zhanjiang 524023, China.
authors.forename: X
authors.initials: X
authors.lastname: Liao
authors.forename: W
authors.initials: W
authors.lastname: Tang
authors.forename: Q
authors.initials: Q
authors.lastname: Cai
authors.forename: F
authors.initials: F
authors.lastname: Li
authors.forename: Z
authors.initials: Z
authors.lastname: Fu
mesh_terms: D015720:5'-Nucleotidase / Q000096:biosynthesis*; D000818:Animals; D001426:Bacterial Proteins; D006801:Humans; D006820:Hyaluronic Acid / Q000097:blood; D007150:Immunohistochemistry; D008208:Lymphatic System / Q000098:blood supply* / Q000378:metabolism*; D008565:Membrane Proteins / Q000096:biosynthesis*; D051379:Mice; D008819:Mice, Nude; D009303:Nasopharyngeal Neoplasms / Q000378:metabolism / Q000473:pathology; D020794:Receptor Protein-Tyrosine Kinases / Q000096:biosynthesis*; D017978:Receptors, Growth Factor / Q000096:biosynthesis*; D012509:Sarcoma / Q000378:metabolism / Q000473:pathology; D013274:Stomach Neoplasms / Q000378:metabolism* / Q000473:pathology; D040321:Vascular Endothelial Growth Factor Receptor-3
chemical_list: D001426:Bacterial Proteins; D008565:Membrane Proteins; D017978:Receptors, Growth Factor; D006820:Hyaluronic Acid; D020794:Receptor Protein-Tyrosine Kinases; D040321:Vascular Endothelial Growth Factor Receptor-3; D015720:5'-Nucleotidase