대한대장항문학회

Colorectal cancer is one of the malignant tumours of which molecular genetic<br>alterations have been much unveiled among the human cancers. In the multi-stepwise<br>process to the carcinogenesis, it has been recently revealed that the neoplastic growth is<br>originated either from the activiation of oncogene through its mutation, rearragement and<br>amplification, or from the inactivation of the tumour suppression gene through its<br>mutation and deletion. DCC(Deleted in colon cancer) protein is the product of DCC gene,<br>the representative of tumor suppressor genes. The alteration of DCC protein may be<br>related with the aggressiveness of carcinoma and metastasis. As a result, the prognosis<br>of the cancer may be also thought to be affected. Now the prognosis of colorectal<br>cancer mainly depends on pathologic staging, but there are some variations of survival<br>and recurrence among the patients in same stage. Then this study is aimed to reveal<br>the significance of alteration of DCC protein as an independent factor related to<br>prognosis.<br>Twenty three cancer tissues were obtained from the rejected specimens of colorectal<br>carcinomas. We exacted the DCC gene products in the cancer tissues by the methods of<br>immunohistochemical stains and Western blots. We also analyzed the<br>relationships<br>between the alteration of DCC proteins and the status of regional lymph node metastasis<br>or the serum levels of CEA's(carcinoembryonic antigen). As results, we found<br>the<br>abscence or very scanty stains of DCC protein by Western lot in 14 cancer tissues of<br>available 19 cases, but there were all negative responses in immunohistochemical stains.<br>In contrast with above results, there were all positively stains of DCC proteins in<br>corresponding 23 normal colorectal tissues by both the methods. There was no<br>significantly statistical relation between the alteration of DCC proteins and the status of<br>regional lymph node metastasis or the serum level of CEA.<br>In conclusion, we can confirm that the DCC proteins are abscent or very scanty in<br>colorectal cancer tissues and that may be related with the process of carcinogenesis. But<br>the role of DCC protein loss as an independent prognostic factor was not found in this<br>study.<br>