ABSTRACT
<p><b>OBJECTIVE</b>To investigate the MEK and ERK expression and their relationship with clinicopathological parameters in human breast carcinoma, and the effect of preoperative chemotherapy on MEK and ERK protein expression.</p><p><b>METHODS</b>Samples were obtained from 56 patients with breast carcinoma and 8 patients with benign tumors. Sixteen of the 56 patients received preoperative chemotherapy. Western blot and immunohistochemistry were used to measure the expression of MEK1, MEK2 and ERK1, ERK2 protein.</p><p><b>RESULTS</b>MEK2 and ERK1, ERK2 protein levels were increased in breast carcinoma tissue compared with those in adjacent normal tissues (t = 7.244, 5.959, 3.735, P < 0.01) and benign tumors (t = 2.206, P < 0.05). The levels of MEK1 were decreased. The expression of MEK2 protein in ER negative patients was higher than that in ER positive ones. MEK2 protein levels were lower in patients who received preoperative chemotherapy than in those who did not.</p><p><b>CONCLUSION</b>Overexpression of MEK-ERK may play an important role in the development of human breast carcinoma. MEK and ERK protein expressions are inhibited by preoperative chemotherapy.</p>
Subject(s)
Adult , Aged , Female , Humans , Middle Aged , Blotting, Western , Breast Neoplasms , Diagnosis , Metabolism , Immunohistochemistry , MAP Kinase Kinase 1 , MAP Kinase Kinase 2 , MAP Kinase Signaling System , Physiology , Mitogen-Activated Protein Kinase 1 , Metabolism , Mitogen-Activated Protein Kinase 3 , Mitogen-Activated Protein Kinase Kinases , Metabolism , Mitogen-Activated Protein Kinases , Metabolism , Prognosis , Protein Kinases , Metabolism , Protein Serine-Threonine Kinases , Metabolism , Protein-Tyrosine Kinases , MetabolismABSTRACT
Objective To investigate the expression of a novel oncogene Stat3 in colorectal cancer. Methods Western blot analysis was performed on cancerous and normal colonic tissue of 45 patients with colorectal carcinoma. ResultsStat3 protein level increased in colorectal cancer compared with adjacent normal mucosa ( P
ABSTRACT
AIM: The purpose of the study was to examine colon cancer cell lines to determine whether Stat5b/Survivin plays an important role in the process of apoptosis in colon cancer cells. METHODS: Protein lysates were extracted from colon cancer cells. Human colon cancer cell line HT29 was transfected with Stat5b antisense oligonucleotide mediated by liposome. MTT assay was used to measure the proliferation. Flow cytometry was applied to analyze the cell cycle and apoptosis. EMSA was used to detect the activity of Stat5. Western blotting was applied to measure the expression of Stat5, p-Stat5, cyclin D1, Survivin, Bcl-2 and Bcl-xL. RESULTS: Targeting of Stat5 using antisense oligonucleotide against the translation site resulted in apoptosis and downregulaed the expressions of Stat5, p-Stat5, cyclin D1 and Survivin, but not Bcl-2 and Bcl-xL. CONCLUSION: Constitutive activation of Stat5 is associated with the carcinogenesis of colon cancer cells. Blocking of Stat5 signaling inhibits the expression of Survivin and induces apoptosis in colon cancer cells.