Gene expression profilling of anaplastic thyroid carcinomas (ATC) and normal thyroid tissues
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ABSTRACT: ATC are among the most lethal malignancies, for which there is no effective treatment. ATC global gene expression was profiled and compared to normal thyroid tissues, in order to elucidate the molecular alterations contributing to ATC development, and to identify novel therapeutic targets. RNA were extracted from 5 ATC samples. 3 samples were obtained at time of surgery, and were immediately frozen in liquid nitrogen. The RNA from the remaining samples were collected during fine-needle aspiration biopsies, being conserved in RLT buffer (RNeasy Mini Kit, Quiagen) and maintained at -70ºC. RNA were also extracted from 3 normal thyroid samples, which were collected during surgery, taken from the opposite lobe of thyroid tumors. We also hybridized a commercial pool of human thyroid total RNA (BD Bioscience).
Project description:Poorly differentiated thyroid carcinomas (PDTC) represent a heterogeneous, aggressive entity, presenting features that suggest a progression from well-differentiated carcinomas. To elucidate the mechanisms underlying such progression and identify novel therapeutical targets, we assessed the genome-wide expression in normal thyroid tissues, well-differentiated thyroid carcinomas and PDTC. RNA were extracted from 2 normal thyroid tissues taken from the opposite lobe of thyroid tumors, and 24 thyroid carcinomas: 5 PDTC, 7 classic papillary thyroid carcinomas (cPTC), 8 follicular variants of PTC (fvPTC) and 4 follicular thyroid carcinomas (FTC). All samples were obtained at time of surgery and immediately frozen in liquid nitrogen. We also hybridized a commercial pool of human thyroid total RNA (BD Bioscience). PTC were screened for BRAF mutations and rearrangements of RET/PTC and, in addition, follicular variants were also analyzed for RAS mutations and PAX8-PPARG rearrangements. FTC were screened for RAS and PAX8-PPARG rearrangements. PDTC were analyzed for BRAF, RAS and PAX8-PPARG genes.
Project description:The E3 SUMO ligase PIAS2 is expressed at high levels in differentiated papillary thyroid carcinomas but at low levels in anaplastic thyroid carcinomas (ATC), an undifferentiated cancer with very high mortality. Double-stranded RNA–directed RNA interference (dsRNAi) targeting the PIAS2 isoform beta (PIAS2b) inhibits growth of ATC cell lines and patient primary cultures in vitro and orthotopic patient-derived xenografts (oPDX) in vivo, but not of thyroid cell lines or non-anaplastic primary thyroid cultures (differentiated carcinoma, benign lesions, or normal). PIAS2b-dsRNAi also has an anti-cancer effect on other anaplastic human cancers (pancreas, lung, and gastric). Mechanistically, PIAS2b is required for proper mitotic spindle and centrosome assembly, and it is a dosage-sensitive protein in ATC. Strikingly, PIAS2b-dsRNAi induces mitotic catastrophe at prophase. High-throughput proteomics revealed the proteasome (PSMC5) and spindle cytoskeleton as direct targets of PIAS2b SUMOylation at mitotic initiation. PIAS2b-dsRNAi is a promising therapy for ATC and other aggressive anaplastic cancers.
Project description:Anaplastic thyroid carcinoma (ATC) has among the worst prognosis of any solid malignancy. The low incidence of the disease has in part precluded systematic clinical trials and tissue collection, and there has been little progress in developing effective therapies. BRAF and TP53 mutations co-occur in a high proportion of ATC, particularly those associated with a precursor papillary thyroid carcinoma (PTC). In order to develop an adult-onset model of BRAF-mutant anaplastic thyroid carcinoma, we generated a novel thyroid-specific CreER transgenic mouse. We utilize a Cre-regulated BrafV600E mouse and a conditional Trp53 allelic series to demonstrate that p53 constrains progression from papillary to anaplastic thyroid carcinoma. Gene expression and immunohistochemical analyses of murine tumors identified the cardinal features of human ATC including loss of differentiation, local invasion, distant metastasis and rapid lethality. We employed small animal ultrasound imaging to monitor autochthonous tumors, and show that treatment with the selective BRAF inhibitor PLX4720 improved survival, but did not lead to tumor regression or suppress signaling through the MAPK pathway. Combination of PLX4720 and the MEK inhibitor PD0325901 more completely suppressed MAPK pathway activation in mouse and human ATC cell lines, and improved the structural response and survival of ATC-bearing animals. This model expands the limited repertoire of autochthonous models of clinically aggressive thyroid cancer, and these data suggest that small molecule MAPK pathway inhibitors hold clinical promise in the treatment of advanced thyroid carcinoma. Total RNA from five murine papillary thyroid carcinoma (PTC) tumors and five murine anaplastic thyroid carcinoma (ATC) tumors was analyzed.
Project description:Anaplastic thyroid carcinoma (ATC) is a rare but deadly thyroid cancer. In contrast, papillary thyroid carcinoma (PTC) is common and highly curable. Minimally invasive biomarkers are needed to distinguish ATC and PTC. Here, by small RNA-seq we show the differential expression levels of several miRNAs, which include miR-34a and miR-210 in ATC compared to PTC cell lines.
Project description:Currently there is a lack of effective therapies which result in long-term durable response for patients presenting with anaplastic thyroid carcinoma (ATC), a very rare and lethal variant of thyroid cancer. ATC is resistant to chemotherapy, radiation, and targeted therapies currently available. In an effort to identify novel tumor-specific therapeutic targets, we performed high throughput gene array analysis screening numerous ATC cell lines, and compared their gene expression levels to normal thyroid cell lines.
Project description:Currently there is a lack of effective therapies which result in long-term durable response for patients presenting with anaplastic thyroid carcinoma (ATC), a very rare and lethal variant of thyroid cancer. ATC is resistant to chemotherapy, radiation, and targeted therapies currently available. In an effort to identify novel tumor-specific therapeutic targets, we performed high throughput gene array analysis screening numerous patient ATC tumor tissues, and compared their gene expression levels to matched and unmatched normal thyroid tissue samples.
Project description:ATC are among the most lethal malignancies, for which there is no effective treatment. ATC global gene expression was profiled and compared to normal thyroid tissues, in order to elucidate the molecular alterations contributing to ATC development, and to identify novel therapeutic targets.
Project description:Anaplastic thyroid carcinoma (ATC) is the most aggressive form of thyroid cancer, and often derives from pre-existing well-differentiated tumors. We have engineered the first mouse model of ATC by combining in the mouse thyroid follicular cells two molecular hallmarks of human ATC: activation of PI3K (via Pten deletion) and inactivation of p53. By 9 months of age, over 75% of the compound mutant mice develop aggressive, undifferentiated thyroid tumors that evolve from pre-existing follicular hyperplasia and carcinoma. These tumors display all the features of their human counterpart, including pleomorphism, epithelial-mesenchymal transition, aneuploidy, local invasion and distant metastases.
Project description:Anaplastic thyroid carcinoma (ATC) is the most fatal and rapidly evolving endocrine malignancy invading the head and neck region and accounting for the majority of thyroid cancer-associated deaths. Deregulation of microRNA (miRNA) expression promotes thyroid carcinoma progression by modulating reorganization of the ATC transcriptome. Here, we applied comparative miRNA-/mRNA-sequencing in a cohort of 28 thyroid carcinomas to unravel the association of deregulated miRNA and mRNA expression. This identifies 85 miRNAs significantly deregulated in ATC. By establishing a new analysis pipeline we unravel 85 prime miRNA-mRNA interactions supporting the downregulation of candidate tumor-suppressors and upregulation of bona fide oncogenes like survivin (BIRC5) in ATC. This miRNA-dependent reprogramming of the ATC transcriptome provides a mRNA signature comprising 65 genes sharply distinguishing ATC from other thyroid carcinomas. Validation of deregulated protein expression in an independent thyroid carcinoma cohort demonstrates that miRNA-dependent oncogenes comprised in this signature, the transferrin receptor TFRC (CD71) and the E3-ubiquitin ligase DTL, are sharply upregulated in ATC. This upregulation is even sufficient to distinguish ATC from partially differentiated thyroid carcinomas (PDTC). In sum, these findings provide new diagnostic tools and a robust resource to explore key miRNA-mRNA regulation underlying the progression of thyroid carcinoma.
Project description:Currently there is a lack of effective therapies which result in long-term durable response for patients presenting with anaplastic thyroid carcinoma (ATC), a very rare and lethal variant of thyroid cancer. ATC is resistant to chemotherapy, radiation, and targeted therapies currently available. In an effort to identify novel tumor-specific therapeutic targets, we performed high throughput gene array analysis screening numerous patient ATC tumor tissues, and compared their gene expression levels to matched and unmatched normal thyroid tissue samples. RNA was extracted from flash frozen patient tumor and normal samples. Gene array analysis was performed, and resulting expression levels were compared between normal and tumor samples.