Study of Detection Method of Apoptosis in Colorecteal Cancer Tissue

Apoptosis is a specific mode of cell death recognized by a characteristic pattern of morphological, biochemical, and molecular changes, There are several methods of detection of apoptosis. Morphological changes involve a characteristic pattern of chromation and cytoplasm. The landmark of apoptosis is endonucleolysis, with nuclear DNA initially degraded at the linker sections to fragments equivalent to single and multiple nucleosomes. Detection of DNA fragments is situ using the terminal deoxyribonucleotidyl transferase(TDT)-mediated dUTP-digoxigenin nick end labeling (TUNEL) assay is increasingly applied to investigate apoptosis. We studied the detection method of apoptosis morphologically and by using TUNEL assay and examined the correlation of p53 expression and apoptosis.

Forty-five cases of colorectal cancer were selected. The number of apoptotic bodies was expressed as a number per 100 cancer cells. The TUNEL assay was performed with in situ Apoptag kit®.

The mean number of the apoptotic bodies was 2.28 in the patients who survived over 5 years after curative resection and 3.55 in the patients who died within 5 years(p=0.001). There was a relationship between the number of apoptotic bodies which were measured by morphologic study and the results which were measured by TUNEL assay. There was no relationship between p53 expression and apoptosis.

These results suggest that the frequency of apoptotic bodies may be a prognostic factor for colorectal cancer and apoptosis could be measured by morphological study without special study.