Biochemical and Biophysical Research Communications
Cytokeratin 8 associates with the external leaflet of plasma membranes in tumour cells
Section snippets
Materials and methods
Cell lines and primary samples. PCI-1, PCI-13, HLAC-78, HLAC-79, ANT-1, 22-A, and FaDu are squamous cell carcinoma lines derived from head and neck carcinomas. SkBr3 and MCF-7 are breast carcinoma cell lines. HCT-8 is a colon carcinoma cell line. All cell lines were propagated at 37 °C in a 5% CO2-humidified incubator in Dulbecco’s modified Eagle’s medium (DMEM) supplemented with 10% fetal calf serum (Biochrom AG, Berlin, Germany), 100 U/ml penicillin, and 100 μg/ml streptomycin. Cells were
Cytokeratin 8 localizes to the plasma membrane of carcinoma cells
First, we analyzed the expression of CK8 on non-permeabilized carcinoma cell lines of different origin, i.e., head and neck (PCI-1, PCI-13, HLAC-78, HLAC-79, ANT-1, and FaDu, 22-A), breast (SkBr3, MCF-7), cervix (HeLa), colon carcinomas (HCT-8), and adenovirus-transformed human embryonic kidney cells (HEK293), which have an epithelial phenotype. CK8 was detected using an antibody recognizing the 12 most C-terminal amino acids in combination with a FITC-conjugated secondary antibody and measured
Discussion
Upon screening of primary carcinomas with autologous serum antibodies using a novel technology termed AMIDA, we have identified CK8 as a target for the humoral immune response in patients suffering from head and neck squamous cell carcinomas [17]. In this screen, CK8 was isolated from a membrane fraction of cells and was subsequently demonstrated to localize to the plasma membrane of primary carcinomas upon flow cytometry analysis. However, the localization of CK8 at the external leaflet of the
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Combined proteomic and transcriptomic approaches reveal externalized keratin 8 as a potential therapeutic target involved in invasiveness of head and neck cancers
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2013, Biochemical and Biophysical Research CommunicationsCitation Excerpt :In addition, their role in cancer cell migration, invasion and metastasis has been documented [22]. Notably, cytokeratins are distributed also at the tumor cell surface [23–26] with poorly characterized functions. Hembrough et al. [27] showed that surface CK8 served as a plasminogen receptor to capture serum plasminogen, resulting in the digestion of extracellular matrix and tumor metastasis.
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These authors contributed equally to this work.