Abstract:
Objective The objectives of this study were to investigate the clinical significance ofCD133, β-catenin, and APC protein expression in the tumorigenesis and progression of colorectal carcinoma (CRC) as well as evaluate the relationship between the clinico- pathological characteristics of these proteins and prognosis in CRC patients.
Methods The expression levels of CD133, β-catenin, and APC were detected using immunohistochemistry SP (streptavidin peroxidase) assay in tissue microarrays consisting of 135 specimens of CRC and adjacent normal mucosa (ANM) tissues and 74 specimens of colorectal adenoma (CRA) tissues. Clinical follow-up data and survival were assessed using Kaplan - Meier analysis and multivariate Cox regression.
Results The positive rates of CD 133 (45.9%) in CRC were significantly higher than those in CRA (9.5%) and ANM (0%) (P < 0.05), and they were related with the degree of dysplasia of CRA and the degree of differentiation of CRC (P < 0.05). The ectopic expression levels of β-catenin in the cytoplasrrdnucleus of CRC (93.3%) and CRA (85.1%) were higher than those in the cytoplasm/nucleus of ANM (14.8%) (P < 0.05). Loss of expression of β-catenin was significantly higher in the cytomembrane of CRC (45.2%) than in those of CRA (4.1%) and ANM (5.2%) (P < 0.05), and it was associated with lymph node metastasis and Dukes stage of CRC (P < 0.05). The positive rates of APC gradually decreased from 100.0% in ANM to 90.5% in CRA to 34.8% in CRC (P < 0.05). The expression of β-catenion in the cytoplasm/nucleus was positively correlated with CD 133 in CRC (P < 0.05), mainly appearing in the group lacking APC expression. Kaplan - Meier analysis and multivariate Cox regression demonstrated that Dukes stage and loss of expression of β-catenin in the cytomembrane were not only high-risk factors in the prognosis of CRC patients hut also independent prognostic factors for low survival in CRC (P < 0.05).
Conclusion CD133, β-catenin, and APC may play important roles in the tumorigenesis and progression of CRC. CD133 and β-catenin/APC have intrinsic relationships among them. Their detection may be of value in understanding the early diagnosis of CRC and in evaluating the biological behavior and prognosis of the disease.