Expression And Significance Of KLF4 Proteins In Colorectal Cancer

Objective Coloretal carcinoma is one of the most common malignant tumors in our country, with the incidence rate is second only pulmonary carcinoma, gastric carcinoma, hepatocarcinoma. With the changes of the diet and living environment, the incidence rate of colorectal carcinoma increased from 0.06‰ in 60' to 0.24‰ in 90' last century. With the development of modern science and technology, there are more and more new diagnostic and therapeutic modalities. But the prognosis of colorectal carcinoma is remains poor, and the recurrence rate is rather high. But the molecular mechanisms of colorectal carcinoma remains unclear. Krüppel-like factor 4 (KLF4) is expressed abundantly in the epithelial cells of gastrointestinal tract and deregulation of KLF4 was linked to several types of cancer. It is of interest to study the expression and role of KLF4 in colorectal carcinoma.Methods 1. Immunohistochemistry staining was used to detect the expression of KLF4 with the paraffin sections of tissue microarray, which contains 77 colorectal cancers, 40 normal mucosae and 7 adenoma. Evaluation of immunostaining: results were evaluated by two experienced pathologists. In colorectal tissue, brown granule appearing in cytoplasm meant positive expression. Ratio of positive cell number to total cell 11%~50% score 2; 51%—80% score 3; >80% score 4. By the degree of staining: weak score 1; moderate score 2; strong score 3. Combine with the two evaluation totally 4 levels: whether the staining, the rate of positive cells ≤ 10% meant negative expression. 2. Western blotting was used to compare KLF4 expression in colorectal carcinoma to normal mucosa and adenoma of the same patients. Cases of colorectal carcinoma tumor tissues which were removed by operation contrast with normal mucosa whose distance was above 10 centimeter from tumor. β -actin as the internal standard, was performed to detect the level of KLF4 protein between fresh colorectal...