The Association Between ER Expression And Chemosensitivity In Esophageal Adenocarcinoma Cell

Objective: ① The purpose of this study was to find out what kinds of ER isoforms are expressed in Barrett’s diseases and esophageal adenocarcinomas, and try to find the difference between them. ② Another purpose of this study was to assess the responding of 5-FU, Cisplatin and Tamoxifen in different ER expression cell lines,finally we want to estimate the correlation between the effect of 5-FU, Cisplatin and Tamoxifen and expression of different ER isoforms. ③ We aim to assess the combined effect of Tamoxifen and two agents(5-FU and Cisplatin) currently use as chemotherapy in treatment of adenocarcinoma of esophagus.Methods: ①Barrett’s esophagus cell lines(BAR-T,ChTERT,Gi TERT,Qh TERT) and Oesophageal adenocarcinoma cell lines(OE19,OE33,SKGT4,OACP4 C,FLO-1,OACM5.1) were cultured. ② We harvest the cells when the confluence was about 70%, then we used EZQ? Protein Quantitation Kit to test the protein concentration.Finally, we test the expression of ERα,ERβ by Western blotting. Found the appropriate measuring time of MTS and created standard growth curve for 96 hours for the reason of finding how many cells we should plant in the 96-well plates for each cell lines. Treated cells with different 5-FU, Cisplatin,Tamoxifen concentration on cell lines of OE19,OE33,SKGT4,OACP4 C,FLO-1,OACM5.1 for 72 hours on 96-well plates, then to analysis the responding data and try to find the relationship between responding and ER expression with Spearman. ③ We choosen cell lines(OE19, OACM5.1)which expresse different ERα, ERβ to assess the effect of the combination of5-FU+TAM and CIS+TAM.Results: ① The expression levels of ER α and ER β in esophageal adenocarcinoma and Barrett’s esophagus cell lines were assessed by Western blotting. The main isoforms we got in ERα were 90 k Da, 61 k Da; while in ERβ were 59 k Da, 51.5k Da,44.9k Da. However, there is more expression of ERα and ERβ in esophageal adenocarcinoma cell lines, especially in the expression of ERβ44.9k Da, and there is significance between them(P<0.05). ②The appropriate time of MTS to measure is2, 3 hours, while 24 hours is not suit for the experiment. We choose 2000 per well to seed in OE19, OE33, SKGT4 cell lines, while 3000 per well to seed in OACM5.1,OACP4 C, and FLO-1 cell lines according to the standard curve. The responding to5-FU, cisplatin, and tamoxifen is different according to different cell lines, and we found that there is no relationship between responding and the expression of ERα61k Da, ERβ59k Da, ERβ51.5k Da, and ERβ 44.9k Da. However, the responding of tamoxifen is negatively correlated to the expression of ERβ51.5k Da. ③ Tamoxifen can boost the effect of cisplatin in high expression of ERβ and low expression of ERα(OE19), while there is no such an effect in tamoxifen together with 5-FU. There is no such an effect nither tamoxifen along with 5-FU or cisplatin in low expression of ERβ and high expression of ERα(OACM5.1).Conclusion: ① The Barrett’s esophagus cell lines and esophageal adenocarcinoma cell lines all show the expression of ERα and ERβ. However, there is more ER expression in esophageal adenocarcinoma cell lines compared with Barrett’s esophagus cell lines, especially the expression of ERβ 44.9k Da. Probably we can use the expression of ERβ 44.9k Da as a new way to distinguish the Barrett’s esophagus and esophageal adenocarcinoma. At same time, it seems that we found one kinds of new isoforms of ERα--ERα 61 k Da.The responding to 5-FU, cisplatin, and tamoxifen is different according to different esophageal adenocarcinoma cell lines. ② The resonding to tamoxifen is negatively correlated to the expression of ERβ51.5k Da,which indicates that there is a close relationship between ER expression and the responding of tamoxifen. ③The tamoxifen can enhance the effect of cisplatin in high expression of ERβ and low expression of ERα, which indicates that we can use tamoxifen together with cisplatin in the patients of esophageal adenocarcinoma who have a high expression of ERβ and low expression of ERα in order to improve treatment of esophageal adenocarcinoma.