[Correlation between the PTEN/MMAC1/TEP1 expression and cell proliferation and apoptosis in human renal cell carcinoma (RCC)].
OBJECTIVE
PTEN is a tumor suppressor gene with phosphatase activity. It had been proved the aberrant expression and mutation of PTEN in diverse types of human cancer; PTEN is closely associated with occurrence and development of malignant tumor. This study was conducted to investigate the expression of PTEN/MMAC1/TEP1 gene product in human renal cell carcinoma (RCC) and the correlation between the expression of PTEN and the biological behaviors of RCC.


METHODS
The PTEN protein of 44 cases of RCC tissues confirmed by pathology after operation, 15 cases of adjacent normal renal tissues, and 10 cases of non-tumor normal renal tissues were assessed using immunohistochemical technique (SP). Fifteen RCC tissues and 10 normal renal tissues selected respectively from the renal tissues whose PTEN protein expression were positive as well as those from the negative were made to be the cell suspension mingled with paraffin. The proliferative index and the apoptosis incidence were examined by flow cytometry and the correlation between PTEN protein and the proliferation and apoptosis were analyzed.


RESULTS
The expression of PTEN protein was mostly located in the renal cell plasma. The positive incidence of expression PTEN protein in RCC was 36.3% which was prominently lower than those in the adjacent normal tissues (77.3%) and the normal tissues (100.00%) (P< 0.01). There was no significant difference between the different sorts of tissues (P >0.05). The expression of PTEN in stage I, II is much higher than that in stage III, IV(P< 0.05). The proliferative index of RCC whose expression of PTEN protein was positive (5.6+/-0.8)% was significantly lower than that of negative (15.6+/-1.6)% (P< 0.01). While the apoptosis incidence was (6.5+/-1.9)%,which was much higher than that of RCC whose expression was (2.9+/-1.6)% (P< 0.01).


CONCLUSIONS
The positive expression incidence of PTEN protein significantly decreases in RCC tissues. PTEN protein suppresses carcinoma by inducing the cell cycle to be blocked up in G1 phase and increasing the apoptosis incidence. The assessment of the expression PTEN protein is one of the important indexes of the development and prognosis of RCC.
Li
Jin-Yu
JY
Department of Urology, The 175th Hospital of PLA, Zhangzhou, Fujian, PR China. lijinyu0920@sina.com
Cao
Run-Fu
RF
Wang
Hong
H
Xie
Qing-Xiang
QX
Wang
Gong-Xian
GX
Xiong
Li-Sheng
LS
Miao
You-Ren
YR
D000328:Adult; D000368:Aged; D017209:Apoptosis; D002292:Carcinoma, Renal Cell / Q000235:genetics* / Q000473:pathology; D002455:Cell Division; D005260:Female; D005500:Follow-Up Studies; D016147:Genes, Tumor Suppressor; D006801:Humans; D007150:Immunohistochemistry; D007680:Kidney Neoplasms / Q000235:genetics* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D051059:PTEN Phosphohydrolase; D010744:Phosphoric Monoester Hydrolases / Q000032:analysis / Q000235:genetics*; D011379:Prognosis; D025521:Tumor Suppressor Proteins / Q000032:analysis / Q000235:genetics*
D025521:Tumor Suppressor Proteins; D010744:Phosphoric Monoester Hydrolases; D051059:PTEN Phosphohydrolase; C494929:PTEN protein, human