Two-dimensional electrophoresis and immunohistochemical study of calreticulin in colorectal adenocarcinoma and mirror biopsies.

PURPOSE

The purpose of this study was to analyse the polypeptide patterns of colorectal adenocarcinomas and mirror biopsies and to investigate the expression of calreticulin and the relationship of this chaperon to colon cancer.

MATERIALS AND METHODS

The investigation was carried out on 21 adenocarcinomas and 21 mirror biopsies using high-resolution two-dimensional (2D) electrophoresis and immunohistochemical PAP method.

RESULTS

2D electrophoresis revealed several polypeptide patterns that were shown to be upregulated in colorectal adenocarcinomas compared to their mirror biopsies. One polypeptide spot being upregulated in colorectal adenocarcinoma, turned out to be calreticulin. The overexpression of calreticulin was confirmed by further examination in immunohistochemical level.

CONCLUSION

Calreticulin was found overexpressed in colon cancer tissues as compared to the corresponding mirror biopsy tissues. The overexpression was particularly intense to high-malignancy tissues and particularly in the poorly differentiated regions of the tissue. Calreticulin showed a direct relationship to the disease stage, a fact strongly indicating that the functional role of calreticulin is directly associated with tumor growth and metastasis.