Department of Medicine, UMDNJ-Robert Wood Johnson Medical School, New Brunswick, NJ, USA.
Int J Cancer. 2011 Jan 15;128(2):274-82. doi: 10.1002/ijc.25343. Epub 2010 Mar 22.
The mechanism by which gastroesophageal reflux promotes metaplasia→dysplasia→carcinoma is unknown. The aim of the study is to determine if repeated exposure to acid and bile confers a tumorigenic phenotype in a telomerase (hTERT)-immortalized benign Barrett's cell line (BAR-T). BAR-T cells were exposed to acid (pH 4) (A) and bile salt (200 μM glycochenodeoxycholic acid) (B) daily for 5 min up to 65+ weeks. The control cells were grown in parallel without any A or B treatment. Cell morphology, proliferation, transformation, and molecular changes in the gene expression for COX-2, TC22, p53 and p53 target genes were analyzed at 8-12 weeks intervals. At 46 weeks BAR-T cells exposed to (A+B) showed distinct phenotypic changes: forming clusters and acini, and at 65 weeks displayed foci in monolayer, and formed distinct colonies in soft agar. Untreated cells did not show any such changes. In A+B-treated BAR-T cells, COX-2 mRNA increased 10- to 20-fold, TC22 mRNA increased by 2- to 3-fold at 22-65 weeks, p53, MDM2, PERP, and p21mRNA increased 2.5-, 6.4-, 4-, and 2.6-fold respectively when compared to untreated cells at 34 weeks. However, at 58 weeks onward, there was a sharp decline of p53 and its target genes to the baseline level. At 65 weeks A+B-treated BAR-T cells formed tumor in nude mice whereas untreated cells did not. We demonstrate a novel in vitro model of transformation of a benign Barrett's cell line following repeated exposure to A+B over the course of 65 weeks.
胃食管反流促进化生→异型增生→癌的机制尚不清楚。本研究旨在确定反复暴露于酸和胆汁是否会使端粒酶（hTERT）永生化的良性 Barrett 细胞系（BAR-T）获得致瘤表型。BAR-T 细胞每天暴露于酸（pH4）（A）和胆汁盐（200μM 甘氨脱氧胆酸）（B）5 分钟，最长达 65 周+。对照细胞在没有任何 A 或 B 处理的情况下平行生长。每隔 8-12 周分析细胞形态、增殖、转化以及 COX-2、TC22、p53 和 p53 靶基因表达的分子变化。在 46 周时，暴露于（A+B）的 BAR-T 细胞表现出明显的表型变化：形成簇和腺泡，在 65 周时在单层中显示焦点，并在软琼脂中形成明显的集落。未经处理的细胞没有显示出任何这种变化。在 A+B 处理的 BAR-T 细胞中，COX-2mRNA 增加了 10-20 倍，TC22mRNA 在 22-65 周时增加了 2-3 倍，p53、MDM2、PERP 和 p21mRNA 分别增加了 2.5 倍、6.4 倍、4 倍和 2.6 倍与 34 周时未经处理的细胞相比。然而，从 58 周开始，p53 和其靶基因的水平急剧下降到基线水平。在 65 周时，A+B 处理的 BAR-T 细胞在裸鼠中形成肿瘤，而未经处理的细胞则没有。我们展示了一种新的体外模型，即良性 Barrett 细胞系在反复暴露于 A+B 65 周后发生转化。
