[Expression of PTEN-encoding product in different stages of carcinogenesis and progression of gastric carcinoma].
OBJECTIVE
To illustrate the significance of expression of phosphatase and tensin homologue derived from chromosome ten (PTEN) encoding product in normal mucosa, intestinal metaplasia (IM), dysplasia and carcinoma of the stomach, and to evaluate its clinical implication in tumorigenesis and progression of gastric carcinoma.


METHODS
Formalin-fixed and paraffin-embedded tissues from 184 cases of gastric carcinoma, its adjacent normal mucosa, IM and dysplasia were evaluated for the expression of PTEN by SABC immunohistochemistry. PTEN expression was assessed as to tumor stage, lymph node metastasis, Lauren's classification and WHO histological classification of gastric carcinoma. Expression of VEGF protein was also studied in 60 cases of gastric carcinoma, with its correlation with PTEN concerned.


RESULTS
The positive rates of PTEN protein were 100% (102/102), 98.5% (65/66), 66.7% (4/6) and 47.8% (88/184) in normal mucosa, IM, dysplasia and carcinoma of stomach, respectively. The positive rates in the last two groups were lower than the first two (P < 0.01). PTEN was less expressed in advanced gastric carcinoma than in early ones (42.9% vs 67.6%, P < 0.01). The positive rate of PTEN protein was lower in gastric carcinoma with lymph node metastasis than without (40.3% vs 63.3%, P < 0.01). PTEN was less expressed in diffuse-type gastric carcinoma than in intestinal-type (41.5% vs 57.8%, P < 0.05). Signet ring cell carcinoma expressed PTEN stood the lowest (25.0%, 7/28), which was less than well and moderately differentiated ones (61.8%, 21/34) (P < 0.01). Expression of PTEN was inversely correlated with expression of VEGF though without any significance (P > 0.05).


CONCLUSIONS
Loss or reduced expression of PTEN protein is common in carcinogenesis and progression of gastric cancer. Altered expression of PTEN may contribute to carcinogenesis and progression of gastric cancer by increasing angiogenesis, cellular adhesion and mobility and so on. PTEN may be an objective marker for pathologically biological behavior of gastric carcinoma.
Zheng
Hua-chuan
HC
Fourth Laboratory, Cancer Institute, First Hospital, China Medical University, Shenyang 110001, China.
Chen
Ying
Y
Kuang
Li-ge
LG
Yang
Lin
L
Li
Jin-yi
JY
Wu
Dong-ying
DY
Zhang
Su-min
SM
Xin
Yan
Y
D000328:Adult; D000368:Aged; D015197:Carcinogenicity Tests; D002448:Cell Adhesion; D002465:Cell Movement; D018450:Disease Progression; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D009389:Neovascularization, Pathologic; D051059:PTEN Phosphohydrolase; D010744:Phosphoric Monoester Hydrolases / Q000096:biosynthesis* / Q000235:genetics; D013274:Stomach Neoplasms / Q000378:metabolism* / Q000473:pathology; D025521:Tumor Suppressor Proteins / Q000096:biosynthesis* / Q000235:genetics
D025521:Tumor Suppressor Proteins; D010744:Phosphoric Monoester Hydrolases; D051059:PTEN Phosphohydrolase; C494929:PTEN protein, human