Epithelial‐mesenchymal transitions during cell culture of primary thyroid tumors?

Abstract

Fibroblast contamination of epithelial tumor cell cultures is of great concern when examining tumor cells in vitro for specific biochemical and cytogenetic changes. The observations of normal karyotypes in thyroid tumor cell cultures have raised the concern of whether residual tissue fibroblasts might obscure the cytogenetic analysis of transformed epithelial cells. We have characterized early passaged thyroid tumor cells to examine the proportions of epithelial and fibroblastic cell types. Cells were analyzed by immunocytology using antibodies recognizing the thyroid prohormone thyroglobulin, epithelial cytokeratins, and vimentin, a mesenchyme marker. Tumors consisted of one follicular adenoma and five papillary carcinomas. When examined by day 15 in culture, all cells contained filaments composed of vimentin, which most likely represents an adaptation to culture conditions. Double immunofluorescence staining for thyroglobulin and cytokeratin revealed the presence of not only epithelial but also spindle-like fibroblastoid cells possessing thyroid epithelial cell markers. The results suggest that in thyroid tumor cultures there is a unique cell type intermediate between epithelial and mesenchyme phenotypes that must be considered when performing cytogenetic analysis.

Inhibition of vimentin or β1 integrin reverts morphology of prostate tumor cells grown in laminin-rich extracellular matrix gels and reduces tumor growth in vivo

“…Epithelial cells grown on plastic dishes often aberrantly express vimentin (Fig. 1B, top row) albeit at a low level compared to the usual epithelial keratins (27). When grown in 3D, vimentin is not expressed in the P69 subline, akin to expression patterns in vivo (Fig.…”

Spindle Cell Metaplasia in Follicular Adenoma of the Thyroid Gland: Case Report and Review of the Literature

“…The persistence of cytokeratin in the cytoplasm of the newly formed mesenchyme-like cells points strongly that their origin is follicular epithelium, since there is no keratin expression in mesenchymal cells surrounding the follicles in situ. Also, Hermann et al [16] have shown similar morphological findings in thyroid neoplasm. The results suggested that there is a unique cell type intermediate between epithelial and mesenchymal phenotypes that exhibit reactivity with antibodies to cytokeratin, thyroglobulin, and vimentin.…”

Atypical/bizarre spindle-cell epithelial metaplasia in nodular goiter: a potential diagnostic pitfall

“…The spindle-cell metaplastic transformation of follicular epithelium is not at all surprising if we consider that both normal and neoplastic thyroid follicular cells in vitro may undergo an epithelial-mesenchymal transition with a fibroblastic-like appearance characterized by an acquisition of vimentin expression accompanied by a concurrent variable loss of cytokeratin [2,3]. The present case contributes to widen the spectrum of the spindle-cell lesions, which can be encountered in diagnostic practice of thyroid pathology.…”