Cytogenetic and molecular genetic changes in malignant transformation of immortalized esophageal epithelial cells.
The purpose of this study was to evaluate the extent to which the expression of p53, c-myc, bcl-2, ras genes and chromosomes, along with activity of hTERT, impacts on the malignant transformation of immortalized esophageal epithelial cells. The SHEE cell line was established from an embryonic esophageal epithelial cell induced by transduction of E6E7 genes of human papillomavirus type 18 (HPV18E6E7). In cells of the 85th passage (SHEE85), the malignant transformation of SHEE was confirmed by morphology, cell proliferative index and tumor formation in SCID mice. C-myc, p53, bcl-2 and ras genes were assayed by the multi-PCR method with house-keeping gene GAPDH as control. The modal number of chromosomes was analyzed and its expression of subunit of telomerase, hTERT, was assessed by RT-PCR. Expression of HPV18E6E7 was assayed by Western blotting. The results showed that cells of SHEE85 were atypical and exhibited proliferative status with a proliferation index of 45.70%. Tumors formed in SCID mice with invasion of adjacent tissue. The karyotype belonged to hypotriploid and displayed expression of hTERT. C-myc, k-ras, bcl-2 and p53 (expression of phosphoprotein) were positive in SHEE85. Expression of HPV18E6E7 was positive. Taken together, SHEE85 cells were in fully malignant transformation and their molecular mechanism involved the expression of cellular genes, such as p53, bcl-2, c-myc and ras, and aberrance of chromosomes. It is probable that all of these changes were related with HPV18E6E7.
Shen
Zhong-Ying
ZY
Department of Pathology, College of Medicine, Shantou University, Shantou 515031, P.R. China. zhongyingshen@yahoo.com
Xu
Li-Yan
LY
Chen
Min-Hua
MH
Cai
Wei-Jia
WJ
Shen
Jian
J
Chen
Jiong-Yu
JY
Zeng
Yi
Y
D000818:Animals; D002461:Cell Line, Transformed; D002472:Cell Transformation, Viral; D002869:Chromosome Aberrations; D004268:DNA-Binding Proteins; D004847:Epithelial Cells / Q000473:pathology* / Q000502:physiology; D004947:Esophagus / Q000473:pathology* / Q000502:physiology*; D015972:Gene Expression Regulation, Neoplastic; D016259:Genes, myc; D011905:Genes, ras; D006801:Humans; D051379:Mice; D016513:Mice, SCID; D009856:Oncogene Proteins, Viral / Q000235:genetics; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics; D019098:Telomerase / Q000235:genetics; D016159:Tumor Suppressor Protein p53 / Q000235:genetics; D023041:Xenograft Model Antitumor Assays
D004268:DNA-Binding Proteins; C052603:E6 protein, Human papillomavirus type 18; C052633:E7 protein, Human papillomavirus type 18; D009856:Oncogene Proteins, Viral; D019253:Proto-Oncogene Proteins c-bcl-2; D016159:Tumor Suppressor Protein p53; D019098:Telomerase