The incidence of colorectal cancer is on the increase owing to changes in daily diet. In the present study, the methylation status of caudal type homeobox transcription factor 2 (CDX2) gene in lesion tissue of colorectal cancer (CRC) was investigated. Additionally, the correlation between the promoter methylation of CDX2 gene, CRC and gene expression in patients with CRC and normal population was examined. Between April 2014 and May 2015 78 cases with CRC were enrolled in the study. Using methylation-specific polymerase chain reaction (PCR), the promoter methylation of CDX2 in normal tissues and colorectal tissues was examinned. Through the fluorescence quantitative PCR technique, the expression levels of CDX2 gene were determined in a normal population and lesion tissue of patients with CRC. At the same time, we evaluated the levels of the CDX2 gene product in the normal population and lesion tissue of patients with CRC. The results showed that the methylation rate of the promoter region of CDX2 gene in normal colorectal tissue was 43.5%, whereas that in the lesion tissue of CRC was 78.5%. The result was statistically significant (P<0.05). The quantity of mRNA and protein expression of CDX2 gene in colorectal and normal tissue was significantly different (P<0.05). In conclusion, the methylation of the CDX2 gene promoter region was associated with risk of CRC, i.e., methylation of the promoter region of CDX2 gene favors the occurrence of CRC.

Background The roles of different subtypes of tumour‐associated macrophages (TAMs) in predicting the prognosis of colorectal cancer (CRC) remain controversial. In this study, different subtypes of TAMs were investigated as prognostic and predictive biomarkers for CRC. Methods Expressions of CD68, CD86 and CD163 were investigated by immunohistochemistry (IHC) and immunofluorescence (IF), and the correlation between the expression of CD86 and CD163 was calculated in colorectal cancer tissues from 64 CRC patients. Results The results showed that high expressions of CD86+ and CD68+CD86+ TAMs as well as low expression of CD163+ and CD68+CD163+ TAMs were significantly associated with favourable overall survival (OS). The level of CD86 protein expression showed a negative correlation with CD163 protein expression. In addition, CD86 protein expression remarkably negatively correlated with tumour differentiation and tumour node metastasis (TNM) stage, while CD163 protein expression significantly positively correlated with tumour differentiation and tumour size. As an independent risk factor, high expression of CD86 TAMs had prominently favourable prognostic efficacy, while high expression of CD68+CD163+ TAMs had significantly poor prognostic efficacy. Conclusions These results indicate that CD86+ and CD68+CD163+ TAMs as prognostic and predictive biomarkers for CRC.

The aim of the present study was to examine the diagnosis of methylation of CDX2 gene promoter in colorectal cancer (CRC) and assessed its value in the prediction of treatment efficacy. Sixty patients who were diagnosed as CRCs for the first time, 60 patients with hyperplastic polyps (HPs) and adenomas, and 60 patients with inflammatory lesions or healthy patients (control group) were included in the present study. The methylation levels of CDX2 gene promoter were detected by methylation-specific polymerase chain reaction (MSP), and the expression levels of CDX2 mRNA were detected by fluorescence quantitative PCR. Treatment options, such as surgery, radiotherapy and chemotherapy, were chosen on the basis of TNM staging of CRC patients. The tumor-free survival, relapse rate and mortality were also recorded. The methylation rate was 71.67% (43/60) and significantly higher in the CRC group as compared to the HP/adenoma and control groups, P<0.05. Moreover, they showed further increase with higher degree of TNM staging. The expression levels of CDX2 mRNA was significantly lower in the CRC group in comparison to HP/adenoma and control groups, P<0.05, and showed a further decrease with a higher degree of TNM staging. The tumor-free survival was shorter, and the relapse rate and mortality were higher in patients with positive methylation in the CRC group, P<0.05. Multivariate logistic regression analysis demonstrated that TNM staging and positive methylation were independent risk factors of mortality. In conclusion, higher methylation degree of CDX2 gene promoter resulted in decreased expression of CDX2 gene, and was closely associated with TNM staging and prognosis. TNM staging and positive methylation were independent risk factors of mortality for CRC patients.