[Dual effect of angiopoietin-2 on angiogenesis in gastric cancer].
OBJECTIVE
To explore the effect of Ang-2 on angiogenesis in gastric cancer.


METHODS
The expression of Ang-2 mRNA was analyzed by RT-PCR and the expression of VEGF and CD34 was detected by immunohistochemistry in 36 cases of gastric cancer tissues and their paired adjacent gastric mucosa.


RESULTS
The expression of Ang-2 mRNA was found both in gastric cancer and their paired adjacent gastric mucosa; the correlationship between the general expression levels of Ang-2 mRNA and microvessel density (MVD) in gastric cancer tissues was not found. However, in 27 cases whose Ang-2 mRNA expression levels in cancer tissues were lower than those in adjacent gastric mucosa. A significant positive correlation between the expression level of Ang-2 mRNA and MVD in the tumor tissues was found (r = 0.411, P < 0.05). In these 27 cases, the MVD in the gastric cancer tissues with positive VEGF expression (45.45 +/- 10.30) was higher than that with negative VEGF expression (30.15 +/- 8.69, P < 0.05), whereas in the other 9 cases whose expression levels of Ang-2 mRNA in cancer tissues were higher than those in adjacent gastric mucosa, a significant negative correlation between expression level of Ang-2 mRNA and MVD in the tumor tissues (r = -0.758, P < 0.05), but without correlation between the MVD and VEGF.


CONCLUSIONS
Under the conditions that the expression of Ang-2 mRNA in cancer tissues was lower than that in adjacent gastric mucosa, VEGF could promote the sprouting of new vessels along with Ang-2 upregulation. But under the conditions that the expression of Ang-2 mRNA in cancer tissues was higher than that in adjacent gastric mucosa, Ang-2 inhibited angiogenesis. Angiopoietin-2 may play a dual effect on angiogenesis in gastric cancer.
Chen
Lin-Ying
LY
The First Affiliated Hospital of Fu Jian Medical University, Fuzhou 350005, China.
Zhang
Sheng
S
Lin
Jian-Yin
JY
Huang
Pei-Sheng
PS
D042702:Angiopoietin-2 / Q000235:genetics / Q000502:physiology*; D005260:Female; D005753:Gastric Mucosa / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D009389:Neovascularization, Pathologic / Q000209:etiology*; D012333:RNA, Messenger / Q000032:analysis; D013274:Stomach Neoplasms / Q000098:blood supply*; D042461:Vascular Endothelial Growth Factor A / Q000032:analysis
D042702:Angiopoietin-2; D012333:RNA, Messenger; D042461:Vascular Endothelial Growth Factor A