Characterization of naturally occurring floating cells and adherent cells within the CEA producing UP LN1 carcinoma cell line in vitro: Identification of cancer stem cells with …

Previously we have documented an initial characterization of a cell line (UP-LN1) from a lymph node metastatic lesion of the neck of a male patient with unknown primary. This tumor was poorly differentiated, and was likely of gastrointestinal tract origin, based on the immunophenotype, CK7-/CK20+/CEA+/SCCA-detected in the original lymph node metastatic lesion and cultured cells. The persistent appearance of floating (designated F) cells along with attachment (A) cells in culture prompted us to investigate into the nature of these two cell types in this study. We found that (i) F and A cells could be isolated and maintained in culture independently;(ii) F cells grew faster and larger than A cells as xenografts in nude mice when injected subcutaneously; and (iii) F cells expressed greater amounts of mRNAs of selected cancer stem cell (CSC) and stem-like cell marker genes, including PSCA (prostate stem cell antigen …