[The relationship between PTEN expression and PI3K/AKT signal pathway in colon carcinoma].

OBJECTIVE: To investigate the expression of PTEN in carcinogenesis and development of colon carcinoma and to reveal their correlation with the PI3K/AKT pathway. METHODS: The expressions of PTEN and p-AKT were detected by immunohistochemistry and western blotting in 32 specimens from patients with colon carcinoma. RESULTS: The positive rate of p-PTEN was significantly lower in colon carcinoma (31.25%) than that in normal control tissues (96.87%, P<0.01), and the positive rate of p-AKT was significantly higher in colon carcinoma (87.5%) than that in normal control tissues (15.62%, P<0.01), and expression level of PTEN and p-AKT were related to histological differentiation, distant invasion, lymph node metastasis and Duke's stage (P<0.05). A negative correlation was observed between the expression of PTEN and p-AKT proteins. (r=-0.872, P<0.01). CONCLUSION: The over-expression of AKT accompanied by the loss of PTEN involves carcinogenesis and development of colon carcinoma.

[Change from inflammation to carcinoma in ulcerative colitis: the role of PTEN/PI3K/AKT].

OBJECTIVE: To detect the changes of expression of PTEN protein and AKT protein in patients with Ulcerative Colitis (UC) in the pathway from inflammation to carcinoma. METHODS: A total of 110 paraffin colorectal sections were examined, which included 65 cases with UC, 25 cases with colorectal cancer and 25 cases with normal tissues. The expression of PTEN protein and AKT protein was detected with immunohistochemistry. RESULTS: (1) The patients with UC had lower expression of PTEN protein and higher expression of AKT than those with normal tissues (P < 0.01). (2) The patients with UC had higher expression of PTEN protein and lower expression of AKT protein than those with colorectal cancer (P < 0.01). (3) With the progress of UC, the expression of PTEN protein decreased while the expression of AKT protein increased (P < 0.01). (4) The expression of PTEN protein was negatively correlated with the expression with AKT protein in patients with UC and colorectal cancer (r = -0. 542 and -0. 674, respectively P < 0.01). CONCLUSION: The change of expressions of PTEN protein and AKT protein might play an important role in the development of UC and colorectal cancer. Decreased PTEN protein and increased AKT protein might be a marker for the early detection of the occurrence of colorectal cancer in patients with UC.