[Evolution of human esophageal cancer cell in the process of cell line establishment]

An esophageal cancer cell line EC8501 was established by tissue culture technique in vitro. Biologic appraisements demonstrated that this cell line was certainly a malignant one. The authors counted chromosome number of 1,284 cells from 10 to 30 passages and discovered that the modal chromosome number was 46 in 10 and 13 passages, 47 in 14 passage and 65 or so after 25 passage. It was a cell population with subtriploid G-banded chromosome analysis of 73 cells from 7 passages (13, 15, 25-27, 29 and 30) showed that structural chromosome aberrations were manifold, complicated and changeable. Sixteen marker chromosomes were present at appearance rate of 11-97%, 6 of which appeared in every passage. Many derivative chromosomes in the 13-30 passages were derived from marker chromosomes. Thirteen markers were first discovered in the 13 passage and 16 of rearrangement points on the markers were close to 7 oncogenes and 7 cancer breakpoints. Two of thirteen markers (del 1p13 and der 2) were similar or same to markers found in epithelium adjacent to esophageal cancer of two patients. The authors suggested that the two markers may reflect the chromosome changes in early carcinogenesis of esophageal epithelium. According to this research, the authors consider that the tumor cell lines cultured in vitro for many years can not reflect the characteristics of tumor cells in vivo.