| Theme |
Colorectal carcinoid tumors -- New strategy of treatment |
| Title |
Genetic alterations of neuroendocrine cell tumor during its development and progression |
| Author |
Hitoshi Kawamata |
Department of Surgical and Molecular Pathology, Dokkyo University School of Medicine |
| Author |
Johji Imura |
Department of Surgical and Molecular Pathology, Dokkyo University School of Medicine |
| Author |
akahiro Fujimori |
Department of Surgical and Molecular Pathology, Dokkyo University School of Medicine |
| [ Summary ] |
We proposed a hypothetical pathway for the development of neuroendocrine cell (NEC) tumors, carcinoid and NEC carcinoma in the digestivetract. We presented a case with a composite tumor, consisting of adenocarcinoma and argyrophil NEC carcinoma. All tumor regions showed a point mutation in p53 gene at exon 7 (GGC to GTC at codon 245). The distal portion of NEC carcinoma showed an additional point mutation in p53 gene at exon 5 (GCC to GTC at codon 129). On the other hand, we investigated the expression of COX-2, and the relationship between COX-2 expression and K-ras mutation in colorectal adenomas. We found that COX-2 was expressed in some NECs in the adenomas. An increase of COX-2-positive cells in adenoma was observed in 11 out of 29 lesions, 10 of which had a K-ras gene mutation. Moreover, most of the colorectal adenocarcinomas over-expressed COX-2 and showed K-ras mutation, whereas none of the NEC tumors showed either over-expression of COX-2 or K-ras mutation.
These results indicate that adenocarcinoma and NEC carcinoma are sometimes derived from a common epithelial cells in the digestive tract, and that different genetic alterations may also be involved in the development of colorectal adenocarcinoma and NEC tumors. |