Project description:Well-differentiated tumours (WDT) of the thyroid gland can be difficult to diagnose. Focal nuclear clearing can be suggestive of a papillary thyroid carcinoma (PTC), while questionable vascular or capsular penetration may raise the possibility of diagnosis of a follicular thyroid carcinoma (FTC). The recently proposed term “thyroid tumours of uncertain malignant potential” (TT-UMP) defines cases showing inconclusive morphological evidence of malignancy. We use microRNA (miRNA) expression profiling to analyze 42 well differentiated thyroid tumours including 7 follicular tumours of uncertain malignant potential (FT-UMP), 6 well differentiated tumours of uncertain malignant potential (WDT-UMP), 7 follicular thyroid adenomas (FTA), 5 follicular variant of papillary thyroid carcinoma (FV-PTC) 6 follicular thyroid carcinoma (FTC), and 11 conventional papillary thyroid carcinoma (C-PTC) with 6 C-PTC mutated for BRAFV600E (C-PTC-mut) and 5 not mutated: wild type (C-PTC-wt). Comparison of these 13 tumours of uncertain malignant potential (7 FT-UMP and 6 WDT-UMP) with those obtained from 16 PTC (11 C-PTC and 5 FV-PTC), 6 FTC and 7 FTA is performed in order to clarify the relationships between TT-UMP and the morphologically well characterized categories of thyroid tumours (i.e. C-PTC, FV-PTC, FTC and FTA). In first, each pathological sample (“L” for Lesional tissue) is compared with its matched control (“S” for Safe tissue) for the 42 patients (84 miRNA microarray slides). This control was taken from the same patient at a large distance from the tumour. Secondly, the perilesional tissue from the same patients but 2 (1 PTC and 1 adenoma, without enough RNA left) is compared to normal thyroid tissue (safe tissue reference) obtained from a patient who underwent total thyroidectomy for a laryngeal carcinoma that partially invaded the thyroid gland, to search for microRNA signatures of perilesional tissues (80 miRNA microarray slides).Experiments is performed with a miRNA microarray, referenced in GEO under the accession number GPL4717 (http://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GPL4717).

Project description:To comprehensively characterize microRNAs (miRNA) expression and their target genes in thyroid cancer, we performed next-generation sequencing expression analysis of this disease. Recent studies have found that only the most abundant microRNAs mediate significant target suppression. We sequenced small RNA from 8 papillary thyroid carcinomas (PTC) with paired samples of normal thyroid tissue. We found that only a small set of abundant miRNAs are differentially expressed after pair-wise comparison (12 upregulated and 8 downregulated) reaching the minimum threshold amount to repress target mRNAs. We integrated computational prediction of potential targets and mRNA sequencing from the paired normal and tumor thyroid tissues from the same eight patients with PTC. The integrated analyses identified a master microRNA regulatory network in PTC that is involved in essential biological processes such as thyroid differentiation. As both mature products of miR-146b (miR-146b-5p and -3p) were among the most abundant upregulated in tumors, we unveil their target genes and found that miR-146b-3p specifically binds to the 3`UTR of PAX8 and NIS, leading to an impaired translation of the proteins and subsequently decreasing the iodide uptake of the cells. Furthermore, we show that mir-146b and PAX8 regulate each other, describing a novel regulatory circuit that determines the differentiated phenotype of PTC. In conclusion, our integrative genomic analysis uncovers the target genes of two of the most upregulated miRNAs and highlights the importance of a miR-146b3p-PAX8-NIS regulatory circuit that determines thyroid differentiation in thyroid cancer. Samples from Papillary Thyroid Carcinoma tumors (n=8) and contralateral normal thyroid tissue from the same patient (n=8) were collected at the Biobank of the Hospital Universitario La Paz (Madrid, Spain). The clinical characteristics of patients are summarized in Table S1. Surgically removed tissues were quickly frozen in liquid nitrogen until analysis. The samples were snap frozen on dry ice and stored at -80°C.

Project description:Well-differentiated tumours (WDT) of the thyroid gland can be difficult to diagnose. Focal nuclear clearing can be suggestive of a papillary thyroid carcinoma (PTC), while questionable vascular or capsular penetration may raise the possibility of diagnosis of a follicular thyroid carcinoma (FTC). The recently proposed term “thyroid tumours of uncertain malignant potential” (TT-UMP) defines cases showing inconclusive morphological evidence of malignancy. We use microRNA (miRNA) expression profiling to analyze 42 well differentiated thyroid tumours including 7 follicular tumours of uncertain malignant potential (FT-UMP), 6 well differentiated tumours of uncertain malignant potential (WDT-UMP), 7 follicular thyroid adenomas (FTA), 5 follicular variant of papillary thyroid carcinoma (FV-PTC) 6 follicular thyroid carcinoma (FTC), and 11 conventional papillary thyroid carcinoma (C-PTC) with 6 C-PTC mutated for BRAFV600E (C-PTC-mut) and 5 not mutated: wild type (C-PTC-wt). Comparison of these 13 tumours of uncertain malignant potential (7 FT-UMP and 6 WDT-UMP) with those obtained from 16 PTC (11 C-PTC and 5 FV-PTC), 6 FTC and 7 FTA is performed in order to clarify the relationships between TT-UMP and the morphologically well characterized categories of thyroid tumours (i.e. C-PTC, FV-PTC, FTC and FTA). In first, each pathological sample (“L” for Lesional tissue) is compared with its matched control (“S” for Safe tissue) for the 42 patients (84 miRNA microarray slides). This control was taken from the same patient at a large distance from the tumour. Secondly, the perilesional tissue from the same patients but 2 (1 PTC and 1 adenoma, without enough RNA left) is compared to normal thyroid tissue (safe tissue reference) obtained from a patient who underwent total thyroidectomy for a laryngeal carcinoma that partially invaded the thyroid gland, to search for microRNA signatures of perilesional tissues (80 miRNA microarray slides).Experiments is performed with a miRNA microarray, referenced in GEO under the accession number GPL4717 (http://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GPL4717). 42 Patients: 7 FT-UMP, 6 WDT-UMP, 7 FTA (+1 duplicate sample), 5 FV-PTC, 6 FTC (+ 2 duplicate samples), and 11 C-PTC. 44 dye-swap pairs and 1 with no dye swap pair for a total of 89 samples.

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