Effects of EpCAM overexpression on human breast cancer cell lines

Abstract

BackgroundRecently, EpCAM has attracted major interest as a target for antibody- and vaccine-based cancer immunotherapies. In breast cancer, the EpCAM antigen is overexpressed in 30-40% of all cases and this increased expression correlates with poor prognosis. The use of EpCAM-specific monoclonal antibodies is a promising treatment approach in these patients.MethodsIn order to explore molecular changes following EpCAM overexpression, we investigated changes of the transcriptome upon EpCAM gene expression in commercially available human breast cancer cells lines Hs578T and MDA-MB-231. To assess cell proliferation, a tetrazolium salt based assay was performed. A TCF/LEF Reporter Kit was used to measure the transcriptional activity of the Wnt/β-catenin pathway. To evaluate the accumulation of β-catenin in the nucleus, a subcellular fractionation assay was performed.ResultsFor the first time we could show that expression profiling data of EpCAM transfected cell lines Hs578TEpCAM and MDA-MB-231EpCAM indicate an association of EpCAM overexpression with the downregulation of the Wnt signaling inhibitors SFRP1 and TCF7L2. Confirmation of increased Wnt signaling was provided by a TCF/LEF reporter kit and by the finding of the nuclear accumulation of ß-catenin for MDA-MB-231EpCAM but not Hs578TEpCAM cells. In Hs578T cells, an increase of proliferation and chemosensitivity to Docetaxel was associated with EpCAM overexpression.ConclusionsThese data show a cell type dependent modification of Wnt signaling components after EpCAM overexpression in breast cancer cell lines, which results in marginal functional changes. Further investigations on the interaction of EpCAM with SFRP1 and TCF7L2 and on additional factors, which may be causal for changes upon EpCAM overexpression, will help to characterize unique molecular properties of EpCAM-positive breast cancer cells.

Near-Infrared Light-Responsive Hydrogel for Specific Recognition and Photothermal Site-Release of Circulating Tumor Cells

“…22 The decreased capture efficiency in whole blood was possibly caused by the blockage from red blood cells and the reduced interaction chance between conjugate and the target cells. 53 …”

“…EpCAM is frequently over-expressed by many kinds of solid-cancer cells and is absent from hematologic cells. 52 Here, EpCAM-positive breast cancer cell line (MCF-7) was chosen as the target cell lines, 53 and EpCAM-negative cancer cell lines (HeLa cervical cancer cell line) and white blood cell (WBC)) were selected as the control. 54 As shown in Figure 3d 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 11 that the immunoaffinity interaction and the topographic interaction between imprinted micro-nanostructures and the target cells synergistically improve the capture efficiency.…”

Characterization of microfluidic shear-dependent epithelial cell adhesion molecule immunocapture and enrichment of pancreatic cancer cells from blood cells with dielectrophoresis

“…4,[11][12][13][14] A majority of immunocapture techniques use the epithelial marker EpCAM (epithelial cell adhesion molecule), which has been reported to have oncogenic potential, 15 is correlated with proliferation in cancer cell lines, 16 and has been used to identify CTCs in many cancers. 11,13,[17][18][19][20][21][22][23] However, EpCAM varies in expression level between cancers and potentially fails to capture more invasive CTCs that have undergone the epithelial-to-mesenchymal transition (EMT).…”

Analysis of the specificity and selectivity of anti-EpCAM antibodies in breast cancer cell lines

“…Similarly to the data of Gostner et al [26], localisation of EpCAM in the cell was determined by cell culture density. We also found that highly confluent monolayers showed strong membranous EpCAM expression, while separated cells exhibited a much weaker signal.…”