COX-2、β-cat、MMP-7表达与遗传性非息肉病性大肠癌特殊侵袭转移行为的关系

Expression of key members of classical Wnt signal pathway in Peutz-Jeghers syndrome

AIM: To detect the expression of E-cadherin (E-Cad), β-catenin (β-Cat), matrix metalloproteinase-7 (MMP-7), c-Myc and Cyclin D1 proteins in Peutz-Jeghers syndrome (PJS).

METHODS: Immunohistochemistry was used to detect the protein expression of E-Cad, β-Cat, MMP-7, C-Myc and Cyclin D1 in 40 cases of PJS, 20 cases of colorectal cancer and 20 cases of normal colorectal mucosa. The clinical data for the included patients were analyzed retrospectively.

RESULTS: The positive rates of E-Cad and β-Cat expression on the membrane, β-Cat expression in the nucleus, and MMP-7, c-Myc and Cyclin D1 expression differed significantly among the normal mucosa group, PJS group and colorectal cancer group. In the PJS group, the expression of E-Cad and β-Cat on the membrane increased with the increase in patient age or polyp size, and the expression of β-Cat in the nucleus and the expression of MMP-7, c-Myc and Cyclin D1 increased with the increase in polyp size. The expression of E-Cad and β-Cat on the membrane had a negative correlation with that of β-Cat in the nucleus and the expression of MMP-7, c-Myc and Cyclin D1 in PJS.

CONCLUSION: The aberrant activation of classical Wnt pathway and the epithelial- mesenchymal transition mediated by Wnt signalling may play an important role in the tumorigenesis and development of PJS. This may correlate with the crosstalk with the LKB1/mTOR pathway.

P27 expression in colorectal cancer: Significance and correlation with expression of Ki-67, P170, MLH1, MSH2, and MSH6

AIM: To investigate the relationship between P27 expression and tumor invasion, metastasis, multidrug resistance and prognosis of colorectal cancer (CRC), and to explore the possible mechanisms involved.

METHODS: Two hundred and sixty-three sporadic CRC patients who underwent surgery in the Department of Colorectal Surgery, Beijing Cancer Hospital from March 2008 to March 2012 were included in this study. All patients were diagnosed by histological examination and did not undergo chemoradiotherapy before surgery. Immunohistochemistry was used to detect P27, Ki-67, P170, MLH1, MSH2 and MSH6 protein expression in samples from these patients. The association between expression and clinical data was analysed retrospectively.

RESULTS: The positive rates of P27, Ki-67, P170, MLH1, MSH2 and MSH6 expression in CRC were 71.1%, 81.4%, 82.5%, 86.7%, 87.8% and 71.1%, respectively. Deficient expression of P27 was closely associated with tumour size, location, differentiation, invasion depth, vascular invasion and lymph node metastasis, but had no association with patients' gender, age, or tumor macroscopic morphology. P27 expression was negatively correlated with Ki-67 and P170 expression (r = -0.315, -0.163, P = 0.00, 0.01), but positively with MLH1, MSH2 and MSH6 expression (r = 0.129, 0.136, 0.159, P = 0.03, 0.03, 0.01).

CONCLUSION: P27 expression is closely associated with the development, invasion and metastasis of CRC. P27 protein expression can be regarded as an important parameter for evaluation of colorectal cancer progression and for selection of chemotherapy drugs and prevention of multidrug resistance.