1 research outputs found
In Vitro Identification and Characterization of CD133pos Cancer Stem-Like Cells in Anaplastic Thyroid Carcinoma Cell Lines
Background: Recent publications suggest that neoplastic initiation and growth are dependent on a small subset of cells,
termed cancer stem cells (CSCs). Anaplastic Thyroid Carcinoma (ATC) is a very aggressive solid tumor with poor prognosis,
characterized by high dedifferentiation. The existence of CSCs might account for the heterogeneity of ATC lesions. CD133
has been identified as a stem cell marker for normal and cancerous tissues, although its biological function remains
unknown.
Methodology/Principal Findings: ATC cell lines ARO, KAT-4, KAT-18 and FRO were analyzed for CD133 expression. Flow
cytometry showed CD133pos cells only in ARO and KAT-4 (6469% and 57612%, respectively). These data were confirmed by
qRT-PCR and immunocytochemistry. ARO and KAT-4 were also positive for fetal marker oncofetal fibronectin and negative
for thyrocyte-specific differentiating markers thyroglobulin, thyroperoxidase and sodium/iodide symporter. Sorted ARO/
CD133pos cells exhibited higher proliferation, self-renewal, colony-forming ability in comparison with ARO/CD133neg.
Furthermore, ARO/CD133pos showed levels of thyroid transcription factor TTF-1 similar to the fetal thyroid cell line TAD-2,
while the expression in ARO/CD133neg was negligible. The expression of the stem cell marker OCT-4 detected by RT-PCR
and flow cytometry was markedly higher in ARO/CD133pos in comparison to ARO/CD133neg cells. The stem cell markers c-
KIT and THY-1 were negative. Sensitivity to chemotherapy agents was investigated, showing remarkable resistance to
chemotherapy-induced apoptosis in ARO/CD133pos when compared with ARO/CD133neg cells.
Conclusions/Significance: We describe CD133pos cells in ATC cell lines. ARO/CD133pos cells exhibit stem cell-like features -
such as high proliferation, self-renewal ability, expression of OCT-4 - and are characterized by higher resistance to
chemotherapy. The simultaneous positivity for thyroid specific factor TTF-1 and onfFN suggest they might represent
putative thyroid cancer stem-like cells. Our in vitro findings might provide new insights for novel therapeutic approaches