Relationship between Expression of Podoplanin and Lymphatic Metastasis in Gastric Carcinoma

Objective To observe the expression of podoplanin in lymphatic endothelial cells in the gastric carcinoma(GC)so as to provide morphological data for the study on the molecular mechanism of tumor metastasis,as well as to investigate the role of podoplanin in lymphatic metastasis of gastric cancer.Methods The expression of podoplanin in gastric carcinoma,lymph nodes and normal gastric tissues was observed by SP immunohistochemistry.By using podoplanin as the specific marker of lymphatic endothelium,the lymphatic micro-vessel density(LMVD) in gastric carcinoma,adjacent carcinoma tissues and normal tissues were calculated.Results Podoplanin was not expressed in blood vessels,but podoplanin was positively expressed in the GC lymphatics.LMVD of GC tissues and pericancerous gastric tissues((9.19±2.48),(18.19±4.22)) was obviously higher than that in normal gastric tissues(5.60±0.84)(P0.01).LMVD of pericancerous gastric tissue was also higher than that in GC tissues(P0.01).At the same time,LMVD of GC tissue that with lymph node metastasis was higher than that without lymph node metastasis.LMVD of pericancerous gastric tissue that with lymph node metastasis was higher than that without lymph node metastasis.And the differences were statistically significant(P0.05).Conclusion Podoplanin is selectively expressed in lymphatics of GC and could correctly distinguish blood vessels from lymphatic vessels.It could be regarded as the specific marker of lymphatic vessels.The positive rate of podoplanin expression increases in GC and metastatic lymph nodes.Therefore,the increased count of lymphatic vessels possibly contributes to lymphatic spread of GC.