Poorly differentiated and anaplastic thyroid carcinomas: chromosomal and oligo-array profile of five new cell lines

Abstract

Information on gene alterations associated to poorly differentiated (PDTC) and anaplastic thyroid carcinomas (ATC) is scarce. Using human cancer cell lines as a tool for gene discovery, we performed a cytogenetic and oligo-array analysis in five new cell lines derived from two PDTC and three ATC. In PDTC we evidenced, as important, the involvement of the MAPK/ERK kinase pathway, and downregulation of a group of suppressor genes that include E-cadherin. In ATC, downregulation of a specific group of oncosuppressor genes was also observed. Our ATC cell lines presented chromosomal markers of gene amplification, and we were able to identify for the first time the nature of the involved amplicon target genes. We found that the main molecular differences between the two cell line types were related to signal transduction pathways, cell adhesion and motility process. TaqMan experiments performed for five amplicon target genes and for two genes, which allowed a clear distinction between ATC and PDTC: CDH13 and PLAU corroborated array results, not only in the cell lines, but also in an additional set of primary 14 PDTC and three ATC. We suggest that our findings may represent new tools for the development of more effective therapies to the hitherto untreatable ATC. Thyroid malignant neoplasms of follicular cell origin are classified into four main categories: the differentiated papillary (PTC) and follicular (FTC) carcinomas, the poorly differentiated (PDTC) and the undifferentiated or anaplastic (ATC) carcinomas. The differentiated forms are the most common. Poorly differentiated thyroid carcinomas and ATC account for only 5 -10% of the follicular malignancies; however, although rare, they represent a major challenge in oncology as they have a high morbidity and mortality rate (DeLelllis and Williams, 2004).In recent years some progress has been obtained in the identification of the genomic changes associated to the pathogenesis of DTC. In PTC, it is now clear that, in a substantially fraction of tumours, malignant transformation takes place through the constitutive activation of effectors along the MAPK/ERK kinase pathway (Mellilo et al, 2005), and in FTC, the PAX8/PPRAg fusion gene was determined to be an important event in the development of a subset of these carcinomas (Lacroix et al, 2005). At variance, the genetic information concerning PDTC and ATC is very limited. Only 27 PDTC have been evaluated by comparative genomic hybridisation (CGH) analysis, and as far as we are aware, there are no microarray studies on this entity (Wreesmann et al, 2002;Rodrigues et al, 2004). In ATC, it was demonstrated that TP53 (Wynford-Thomas, 1997) and b-catenin (Garcia-Rostan et al, 1999) mutations as well as the overexpression of OEATC1 (Mizutani et al, 2005) and AURKB (Sorrentino et al, 2005) were associated with ATC phenotype. These genes were demonstrated to be key effectors in anaplastic transformation, being responsible for evasion to apoptosis, enhanced tumour growth and replicative potential. However, although all efforts ma...

High periostin expression correlates with aggressiveness in papillary thyroid carcinomas

“…Thus, periostin gene overexpression was statistically correlated with the aggressiveness of the tumor. Global gene expression studies performed by SAGE or microarrays have not detected increase in periostin expression in thyroid carcinomas (Huang et al 2001, Aldred et al 2004, Jarzab et al 2005, Cerutti et al 2007, Delys et al 2007, Fujarewicz et al 2007, Rodrigues et al 2007). These apparently negative results could be explained by technical reasons and by the particular study design (i.e., small number of patient investigated, no paired comparison between normal and tumoral tissues, analysis of low stages only).…”

Gene expression profile of human thyroid cancer in relation to its mutational status

“…Microarray analysis also showed a strong upregulation of PKB (v-AKT murine thymoma viral oncogene homolog 1), which encodes a serine/threonine kinase of the MAPK pathway, in PDTC. The over-expression of PKB in poorly differentiated thyroid carcinomas was first demonstrated by Rodrigues et al (2007b), who emphasized the importance of the MAP kinase pathway in the progression of thyroid carcinomas. Montero-Conde et al (2008) investigated differentiated and undifferentiated thyroid tumors by using cDNA microarrays and also reported significant changes in the expression of genes of the MAPK pathway, as well as those of the TGFb pathway, focal adhesion, and activation of actin polymerization and cell cycle.…”

“…Not unexpectedly, the array-based analyses showed a marked under-expression of thyroid-specific genes in anaplastic thyroid carcinoma (Onda et al 2004, Rodrigues et al 2007b, Matsumoto et al 2008.…”

“…With regard to genes downregulated (lost) in ATC, Rodrigues et al (2007b) reported the downregulation of pleomorphic adenoma gene-like 1 (PLAGL1) and described under-expression of CDH1 (cadherin 1, type 1, E-cadherin (epithelial)) in PDTC. Most downregulated genes described by Pita et al in PDTC in comparison to normal thyroid tissue were related to cell adhesion.…”

A Human Thyroid Cancer Cell Line, DH-14-3, Newly Established from Poorly Differentiated Thyroid Carcinoma

“…Only a few established cell lines of PDTC have been reported (Asakawa and Kobayashi 1999;Rodrigues et al 2007), but the biological features of PDTC remain to be investigated. We herein report the establishment and characteristics of a new PDTC cell line, DH-14-3.…”