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To outline further genetic mechanisms of transformation from follicular lymphoma (FL) to diffuse large B-cell lymphoma (DLBCL), we have performed whole genome array-CGH in 81 tumors from 60 patients [29 de novo DLBCL (dnDLBCL), 31 transformed DLBCL (tDLBCL), and 21 antecedent FL]. In 15 patients, paired tumor samples (primary FL and a subsequent tDLBCL) were available, among which three possessed more than two subsequent tumors, allowing us to follow specific genetic alterations acquired before, during, and after the transformation. Gain of 2p15-16.1 encompassing, among others, the REL, BCL11A, USP34, COMMD1, and OTX1 genes was found to be more common in the tDLBCL compared with dnDLBCL (P < 0.001). Furthermore, a high-level amplification of 2p15-16.1 was also detected in the FL stage prior to transformation, indicating its importance during the transformation event. Quantitative real-time PCR showed a higher level of amplification of REL, USP34, and COMMD1 (all involved in the NF kappa B-pathway) compared with BCL11A, which indicates that the altered genes disrupting the NF kappa B pathway may be the driver genes of transformation rather than the previously suggested BCL11A. Moreover, a 17q21.33 amplification was exclusively found in tDLBCL, never in FL (P < 0.04) or dnDLBCL, indicating an upregulation of genes of importance during the later phase of transformation. Taken together, our study demonstrates potential genomic markers for disease progression to clinically more aggressive forms. We also confirm the importance of the TP53-, CDKN2A-, and NF kappa B-pathways for the transformation from FL to DLBCL.

Papillary thyroid carcinoma (PTC) exhibits various molecular abnormalities, both when sporadic and radiation-related. PTC is still diagnosed in adult individuals who were younger than 18 years at the time of the Chornobyl accident in 1986 and lived within the contaminated area. The preoperative diagnosis of PTC is based on ultrasound-guided fine needle aspiration cytology (FNAC), which is highly informative in up to 90% of biopsies. FNAC is not informative for the discrimination of follicular thyroid carcinoma (FTC) from follicular thyroid adenoma (FTA). Moreover, FNAC is often unreliable for diagnosis of cystic PTC due to its common presentation as a mural nodule in a cystic mass. In case of cystic PTC, biopsy sometimes reveals a cystic fluid containing insufficient amount of representative cells for cytology. In this work, PTC was characterized in relation to irradiation from radioactivity at childhood. Possible preoperative diagnostic markers for discrimination between PTC and other follicular thyroid neoplasms were identified, and their validity was tested. In Study I molecular, genetic and clinical characteristics in 70 post-Chornobyl PTCs were investigated. A common BRAF 1799T>A mutation was detected in 26 cases, overrepresentation of RET/PTC1 in 20 whereas RET/PTC3 was found in 4 cases. BRAF mutation was observed 3.5 times less frequent in the PTC accompanied by chronic lymphocytic thyroiditis (PTC/CLT) as compared to PTC only (12% vs. 44%). Greater expression of cyclin A was observed in PTC ≥ 2 cm as compared to PTC < 2 cm (1.2% vs. 0.6%). In conclusion, BRAF mutation and RET/PTC1 rearrangement as well as other molecular features of adult post-Chornobyl PTC were partly overlapping with other reported PTC cohorts. In Study II the SELDI-TOF mass spectrometry method was applied for PTC, FTC, FTA and normal thyroid tissue (NT). Significant overexpression of the protein S100A6 was identified in PTC as compared to FTC, FTA and NT (p < 0.05). This result was verifi

Objective: Thyroid proteomics is a new direction in thyroid cancer research aiming at etiological understanding and biomarker identification for improved diagnosis. Methods: Two-dimensional electrophoresis was applied to cytosolic protein extracts from frozen thyroid samples (ten follicular adenomas, nine follicular carcinomas, ten papillary carcinomas, and ten reference thyroids). Spots with differential expression were revealed by image and multivariate statistical analyses, and identified by mass spectrometry. Results: A set of 25 protein spots significant for discriminating between the sample groups was identified. Proteins identified for nine of these spots were studied further including 14-3-3 protein beta/alpha, epsilon, and zeta/delta, peroxiredoxin 6, selenium-binding protein 1, protein disulfide-isomerase precursor, annexin A5 (ANXA5), tubulin alpha-1B chain, and alpha 1-antitrypsin precursor. This subset of protein spots carried the same predictive power in differentiating between follicular carcinoma and adenoma or between follicular and papillary carcinoma, as compared with the larger set of 25 spots. Protein expression in the sample groups was demonstrated by western blot analyses. For ANXA5 and the 14-3-3 proteins, expression in tumor cell cytoplasm was demonstrated by immunohistochemistry both in the sample groups and an independent series of papillary thyroid carcinomas. Conclusion: The proteins identified confirm previous findings in thyroid proteomics, and suggest additional proteins as dysregulated in thyroid tumors.