Expression And Clinical Significance Of Survivin Gene And PTEN Protein In Colorectal Adenocarcinoma

OBJECTIVE: The occurrence of colorectal adenocarcinoma is resulted from multiple factors and both Survivin gene and PTEN protein take part in these courses. They all regulate cell cycle and apoptosis, but their biological effects are adverse. It is not completely elucidated about their function and relationship in colorectal adenocarcinoma. This study was designed to investigate the role of Survivin gene and PTEN protein in the pathogenesis of colorectal adenocarcinoma and their correlation. METHODS: To determine the Survivin mRNA in 42 colorectal adenocarcinoma and 20 adjacent normal colorectal tissue samples, we used reverse transcription polymerase chain reaction(RT-PCR) to detect the expression of Survivin mRNA, and immunohistochemical evaluation was used to detect the expression of PTEN protein. RESULTS: Survivin expression was detected in 23 colorectal adenocarcinoma samples (54.8%), while no expression was detected in 20 adjacent normal tissues. The expression of Survivin gene was significantly correlated with histological differentiation and Dukes stage (P<0.05) , but not with gender or lymph node metastasis. PTEN expression was detected in 18 of 20 samples (90.0%)of adjacent normal tissues, only 20 of 42 samples (47.6%) of adenocarcinoma were positive expression, positive rate was lower than that of adjacent normal tissues (x 2=8.548, PO.01). There was no relationship between PTEN protein and gender, while the expression of PTEN was positively correlated with histological differentiation and lymph node metastasis, and possibly correlated with Dukes stage. With the progress of tumor in malignancy, the positive rate of Survivin expression increased, while that of PTEN protein decreased. The rates of Survivin(+)PTEN(-) were 10.0%(1/10), 28.0%(7/25), 71.4%(5/7) in Well, Moderate and Poor differentiation respectively. The ratio demonstrated ascending tendency and there was significant difference amonggroups( x 2=7.447, P<0.05). On the contrary, the rates of Survivin(-)PTEN(+) were 60.0%(6/10), 12.0%(3/25) and 14.3%(l/7) from Well to Poor differentiation respectively. The ratio demonstrated descending tendency and difference was significant x 2=8.557, P<0.05). There was a negative correlation between Survivin and PTEN in colorectal adenocarcinoma. CONCLUSION: Survivin gene and PTEN protein are significantly correlated with the clinicopathological characteristics and biologic behavior in colorectal adenocarcinoma. Detection of Survivin together with PTEN is valuable for diagnosing colorectal adenocarcinoma, and evaluating malignancy extent and prognosis.