Evaluation of CD98 as The Potential Surface Marker of Esophageal Cancer Stem Cells

• Main Authors: Yi-Chun Liu, 劉怡君
• Other Authors: Yann-Jang Chen
• Format: Others
• Language: en_US
• Published: 2016
• Online Access: http://ndltd.ncl.edu.tw/handle/57210612843508482037

碩士 === 國立陽明大學 === 生命科學系暨基因體科學研究所 === 104 === Cancer stem cells (CSCs) are a small subset cell group that has stem cell characteristics in cancer. They are capable of self-renewal and are resistant to drugs and radiation treatment. Esophageal cancer is common in East Asia. However, there is limited information about the biomarker of esophageal CSCs. Our lab established a novel platform to isolate esophageal CSCs. After CSC isolation, we screened the expression of surface markers by expression microarray and literature searching, we then focused on CD98 as potential surface marker of esophageal CSCs. CD98 is a cell-surface heterodimer consisting of a ~80-85 kDa heavy chain (CD98hc) and a ~40 kDa light chain (CD98lc). CD98 expression is associated with the development and progression of many tumors. To understand the role of CD98 in esophageal CSCs, two esophageal cancer cell lines, TE2 and CE-81T/VGH, were used. We first divided the cells into four group, CD98Low, CD9825%, CD9875%, and CD98High cells through FACS sorting. We then analyzed the characteristics of these sorting cells through tumor-sphere formation assay and stemness gene expression assay. Furthermore, we knockdowned CD98hc in esophageal CSCs to investigate its importance in CSCs stem-like properties. Our results revealed that the CD98High cells expressed higher stemness and EMT markers in both mRNA and protein levels, including Oct4, Sox2, Klf4, c-Myc, Nanog, E-cad, Vim, and Snail. Their sphere formation abilities were considerably greater than other sorting cells (roughly two times of fold change). Moreover, the knockdown of CD98 reduced the expression of stemness and EMT markers and also decreased sphere-forming ability. Taken together, high expression of CD98 might involve in regulating the stemness features and cell behavior of esophageal cancer stem cells. Suppression of CD98 might inhibit the stem-like properties of esophageal CSCs. CD98 might be the potential biomarker of esophageal cancers. Targeting the CD98 may provide a new strategy for esophageal cancer therapy.