BACKGROUND Anaplastic thyroid carcinoma (ATC) is the most lethal form of thyroid neoplasia and represents the end stage of thyroid tumor progression. In the current study, genetic alterations in a panel of ATC were profiled to determine the origins of ATC. METHODS Eight ATC were analyzed for BRAF mutation at codon 599 by using mutant‐allele‐specific polymerase chain reaction (PCR) and DNA sequencing of the PCR‐amplified exon 15. RAS mutation (HRAS, KRAS, and NRAS) at codons 12, 13, and 61 was analyzed by direct sequencing of PCR‐amplified exons 1 and 2 of the RAS gene. RET/PTC rearrangements and p53 mutation were monitored by immunohistochemical (IHC) staining by anti‐RET antibodies and an anti‐p53 mAb, respectively. RESULTS BRAF was mutated in 5 of the 8 ATCs tested. Histologic examination revealed that 4 of these 5 BRAF‐mutated ATCs contained a PTC component, suggesting that they may be derived from BRAF‐mutated PTC. Of the 3 ATCs with wild‐type BRAF, 2 had spindle cell features; one had follicular neoplastic characteristics mixed with papillary structures. Analysis of RAS mutation revealed only an HRAS mutation at codon 11, due to the transversion of GCC to TCC in one ATC with wild‐type BRAF. This leads to the substitution of valine to serine. IHC analysis of RET/PTC rearrangements revealed no positive staining of RET in any of 8 ATCs, suggesting that these ATCs are not derived from RET/PTC‐ rearranged PTC. In contrast, IHC analysis of p53 mutation revealed that p53 was detected in the nuclei of 5 of 5 BRAF‐mutated ATCs and 2 of 3 ATCs with wild‐type BRAF. p53 staining was present only in anaplastic thyroid tumor cells but not in neighboring papillary thyroid tumor cells. CONCLUSIONS These results suggest that many ATCs with papillary components are derived from BRAF‐mutated PTC, because of the addition of p53 mutation. Cancer 2005. © 2005 American Cancer Society.

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Objective-Due to a lack of experimental systems, little is known about ovarian stroma. Here, we introduce an in vivo-like 3-D system of mesenchymal stromal progression during ovarian tumorigenesis to support the study of stroma permissiveness in human ovarian neoplasias.Methods-To sort 3-D cultures into 'normal,' 'primed' and 'activated' stromagenic stages, 29 fibroblastic cell lines from 5 ovarian tumor samples (tumor ovarian fibroblasts, TOFs) and 14 cell lines from normal prophylactic oophorectomy samples (normal ovarian fibroblasts, NOFs) were harvested and characterized for their morphological, biochemical and 3-D culture features.Results-Under 2-D conditions, cells displayed three distinct morphologies: spread, spindle, and intermediate. We found that spread and spindle cells have similar levels of α-SMA, a desmoplastic marker, and consistent ratios of pFAKY 397 /totalFAK. In 3-D intermediate cultures, α-SMA levels were virtually undetectable while pFAKY 397 /totalFAK ratios were low. In addition, we used confocal microscopy to assess in vivo-like extracellular matrix topography, nuclei morphology and α-SMA features in the 3-D cultures. We found that all NOFs presented 'normal' characteristics, while TOFs presented both 'primed' and 'activated' features. Moreover, immunohistochemistry analyses confirmed that the 3-D matrix-dependent characteristics are reminiscent of those observed in in vivo stromal counterparts.Conclusions-We conclude that primary human ovarian fibroblasts maintain in vivo-like (staged) stromal characteristics in a 3-D matrix dependent manner. Therefore, our stromal 3-D system offers a tool that can enhance the understanding of both stromal progression and stroma-induced ovarian tumorigenesis. In the future, this system could also be used to develop ovarian stroma-targeted therapies.