未分化型胃癌の系譜解析

抄録

Comparative genomic hybridization (CGH) has been used for a screening of the genes that are responsible for genomic copy-number changes. For this purpose, chromosomal CGH is being replaced by array CGH. Recently, we have applied CGH to lineage analyses in undifferentiated-type gastric carcinomas. We used the DNA that was taken with laser capture microdissection from multiple portions in individual tumors and amplified through DOP-PCR. Comparing the pattern of chromosomal loss/gain at the arm level between poorly differentiated adenocarcinomas (POR) and signet ring cell carcinomas (SIG) and between the tumors with minor tubular component (TC) and those without TC, we have found that most of the POR without TC derives from SIG and that the genetic pathway may be different between the tumors with TC and those without TC. Using the dendrograms that were based on intratumoral heterogeneity analyses, we have demonstrated that large part of the POR with TC derives from tubular adenocarcinoma and small part of them from SIG. Thus, the CGH-based lineage analysis may be a useful tool for the demonstration of genetic lineage between the lesions of different morphology at different loci, and thereby, for a reappraisal of tumor classification.