Impact of Mutation Density and Heterogeneity on Papillary Thyroid Cancer Clinical Features and Remission Probability

BACKGROUND: The need to integrate the classification of cancer with information on the genetic pattern has emerged in recent years for several tumors. METHODS: The genomic background of a large series of 208 papillary thyroid cancers (PTC) followed at a single center was analyzed by a custom MassARRAY genotyping platform, which allows the simultaneous detection of 19 common genetic alterations, including point mutations and fusions. RESULTS: Of the PTCs investigated, 71% were found to have pathognomonic genetic findings, with BRAFV600E and TERT promoter mutations being the most frequent monoallelic alterations (42% and 23.5%, respectively), followed by RET/PTC fusions. In 19.2% of cases, two or more point mutations were found, and the co-occurrence of a fusion with one or more point mutation(s) was also observed. Coexisting BRAFV600E and TERT promoter mutations were detected in a subgroup of aggressive PTCs (12%). A correlation between several aggressive features and mutation density was found, regardless of the type of association (i.e., only point mutations, or point mutations and fusions). Importantly, Kaplan-Meier curves demonstrated that mutation density significantly correlated with a higher risk of persistent disease. In most cases, the evaluation of the allelic frequencies normalized for the cancer cell content indicated the presence of the monoallelic mutation in virtually all tumor cells. A minority of cases was found to harbor low allelic frequencies, consistent with the presence of the mutations in a small subset of cancer cells, thus indicating tumor heterogeneity. Consistently, the presence of coexisting genetic alterations with different allelic frequencies in some tumors suggests that PTC can be formed by clones/subclones with different mutational profiles. CONCLUSIONS: A large mono-institutional series of PTCs was fully genotyped by means of a cost- and time-effective customized panel, revealing a strong impact of mutation density and genetic heterogeneity on the clinical features and on disease outcomes, indicating that an accurate risk stratification of thyroid cancer cannot rely on the analysis of a single genetic event. Finally, the heterogeneity found in some tumors warrants attention, since the occurrence of this phenomenon is likely to affect response to targeted therapies

Integrated genomics analysis of gene and miRNA expression profiles in clear cell renal carcinoma cell lines

Clear cell renal cell carcinoma (ccRCC) is the most common and malignant tumor in the adult kidney, representing 75-80% of renal primary malignancies. Inactivation of the von Hippel-Lindau (VHL) tumor suppressor gene, by mutation, deletion and promoter methylation, occurs in most sporadic ccRCCs and in all inherited cases. Recent evidences showed that microRNAs (miRNAs) are often dysregulated in many tumors, including ccRCC. We used Caki-1, Caki-2 and A498 cell lines as in vitro model of ccRCC pathology, and HK-2 (normal proximal tubular epithelial cell line) as reference sample. We characterized the VHL status by direct sequencing and the HIF status by western blot. Affymetrix microarray technology was applied to assess miRNA (onto GeneChip\uae miRNA Array) and gene expression profiles (onto GeneChip\uae Human Gene 1.0 ST Array). Analysis of common differentially expressed miRNAs (DEMs) in RCC cell lines outlined specific miRNAs to be involved in ccRCC and in cancer (e.g. miR-145, miR-29a, miR-342-3p, miR-205, miR-183, miR-197, miR-132, miR-146a and miR-34a). Functional enrichment analysis of common differentially expressed genes (DEGs) highlighted some genes involved in leucocyte transendothelial migration, focal adhesion and p53 signalling pathways (e.g. ATM, FER, CDC27 and GRB10). Additionally, we conducted an integrated analysis to combine gene and miRNA expression profiles and to reconstruct miRNA-gene post-transcriptional regulatory networks involved in RCC pathology. We also compared our expression data with RCC datasets publicly available from NCBI GEO microarray repository. We selected potentially interesting miRNAs and target genes for further validation (by qPCR). This integrated analysis approach may help to unravel the molecular complexity characterizing ccRCC biology, and it will facilitate the elucidation of regulatory circuits important for tumorigenesis and the biological processes under relevant post-transcriptional regulation in ccRCC

The role of IL-6 released from pulmonary epithelial cells in diesel UFP-induced endothelial activation

Diesel exhaust particles (DEP) and their ultrafine fraction (UFP) are known to induce cardiovascular effects in exposed subjects. The mechanisms leading to these outcomes are still under investigation, but the activation of respiratory endothelium is likely to be involved. Particles translocation through the air-blood barrier and the release of mediators from the exposed epithelium have been suggested to participate in the process. Here we used a conditioned media in vitro model to investigate the role of epithelial-released mediators in the endothelial cells activation. Diesel UFP were sampled from a Euro 4 vehicle run over a chassis dyno and lung epithelial BEAS-2B cells were exposed for 20 h (dose 5 microg/cm2). The exposure media were collected and used for endothelial HPMEC-ST1.6R cells treatment for 24 h. The processes related to oxidative stress and inflammation were investigated in the epithelial cells, accordingly to the present knowledge on DEP toxicity. The release of IL-6 and VEGF was significantly augmented in diesel exposed cells. In endothelial cells, VCAM-1 and ICAM-1 adhesion molecules levels were increased after exposure to the conditioned media. By interfering with IL-6 binding to its endothelial receptor, we demonstrate the role of this interleukin in inducing the endothelial response. DEP modulates oxidative stress, MAPK activation and IL-6 release in lung cells. Treatments with endothelial supernatants induce endothelial activation which is down-regulated by IL-6 suppression

Hyperplastic pituitary gland, high serum glycoprotein hormone alpha-subunit, and variable circulating thyrotropin (TSH) levels as hallmark of central hypothyroidism due to mutations of the TSH beta gene

Inheritable isolated central hypothyroidism (ICH) due to mutations of TSH beta gene has been reported in few patients. For this reason the diagnostic criteria are vague. The disorder is usually characterized by undetectable TSH levels, although low/normal serum TSH, depending on TSH measurement methods, has been documented in some patients. Here we report an Egyptian girl with ICH due to a novel nonsense mutation of the TSH beta gene (Q49X). She was referred at 75 days of age for severe clinical signs of hypothyroidism, whose central origin was documented by normal serum TSH, low free T(4) and free T(3) levels, impaired TSH response to TRH, absence of (99)Tc thyroidal uptake, and antithyroid autoantibodies. Ultrasound revealed a hypoplastic thyroid, whereas magnetic resonance imaging showed a hyperplastic pituitary. All other pituitary hormones, including PRL, were normally secreted. A diagnosis of idiopathic ICH was made, and substitutive L-T(4) treatment was started at 81 days of age. At the age of 7 yr the patient had normal thyroid hormone levels, but was severely mentally retarded. Interestingly, the sella computed tomography scan had completely normalized. At 8 yr of age the patient was reinvestigated after 6-week L-T(4) withdrawal. TSH values were highly variable depending on the measurement method used, whereas extremely high levels of circulating free glycoprotein alpha-subunit were recorded. Despite the fact that mutant TSH beta lacks 60% of the C-terminal amino acid sequence, it forms with the alpha-subunit a heterodimer with preserved immunoreactivity in some TSH measurement methods, but the mutant heterodimer is completely devoid of bioactivity. In conclusion, high circulating free glycoprotein alpha-subunit levels, variable TSH levels, and, possibly, hyperplastic pituitary gland are the hallmark of ICH due to mutations of the TSH beta gene

Polymorphism of Vitamin d receptor gene start codon in patients with calcium kidney stones

BACKGROUND: A linkage has been detected between vitamin D receptor (VDR) locus and calcium kidney stone disease. In order to assess the eventual role of VDR gene start codon polymorphisms in stone production, we analyzed the genotype-phenotype association in a group of patients with calcium kidney stones. METHODS: One hundred and fifty-five patients were studied. VDR genotypes were characterized at the translation start site by restriction fragment length polymorphism analysis, using endonuclease FokI. Phenotypes of calcium-phosphate metabolism were compared in patients with different genotypes: strontium enteral absorption (used as a surrogate marker for calcium absorption), bone mineral density (BMD), calcium and phosphate excretion were measured. RESULTS: Genotype distribution was not different in hypercalciuric and normocalciuric stone formers. Enteral strontium absorption, calcium excretion and BMD did not vary with the patient's genotype. Serum concentrations of phosphate (p=0.022) and renal threshold for phosphate excretion (p=0.026) were lower in patients with genotype FF (homozygous for the absence of the FokI site) than in those with genotype ff (homozygous for the presence of the FokI site). The lower phosphatemia was confirmed in FF hypercalciuric patients, but not in normocalciuric ones. Serum concentrations of phosphate and calcitriol in the group of hypercalciuric patients were inversely correlated with the genotype FF. CONCLUSIONS: The FokI genotype does not appear to be involved in the causes of idiopathic hypercalciuria and kidney stones. Hypercalciuric patients with FF genotype may be a subgroup with low plasma concentrations of phosphate, predisposed to tubular leakage of phosphate

Congenital hypothyroidism with gland in situ: diagnostic re-evaluation

In the past, most congenital hypothyroidism (CH) children with thyroid gland in situ were considered to be affected by hormonogenesis defect. Nowadays, the improved sensitivity of neonatal screening, novel insights into the pathogenic mechanisms and the advances of genetic analyses have reopened the discussion about the etiology of CH with thyroid in situ. We report the etiological re-evaluation of 31 children with thyroid in situ, who had been identified by the CH screening program. The purposes of this re-evaluation were: a) to investigate the definitive diagnosis and pathogenetic mechanism of CH with thyroid in situ in eligible children suspected of dyshormonogenetic defect and b) to verify the adequacy of the treatment schedules. Thirty out of 31 children were affected with permanent hypothyroidism and only one child was euthyroid at re-evaluation (transient CH). Thyroid hormone organisation defects were present in less than half of the CH patients with thyroid in situ (13/30); a higher prevalence of partial defects of iodine organification than severe or complete forms was found. An inactivating TSH-receptor gene mutation was found in only one patient without iodine organification defect. Some questions remain unanswered concerning the adequacy of the schedules of treatment, particularly about the proper treatment of mild and borderline forms of CH

Congenital hypothyroidism with gland in situ: diagnostic revaluation.

In the past, most Congenital Hypothyroidism (CH) children with thyroid gland in situ were considered to be affected by hormonogenesis defect. Nowadays, the improved sensitivity of neonatal screening, novel insights into the pathogenic mechanisms and the advances of genetic analyses have reopened the discussion about the etiology of CH with thyroid in situ. We report the etiological revaluation of 31 children with thyroid in situ, who had been identified by the CH screening program. The purpose of this revaluation was to investigate the definitive diagnosis and pathogenic mechanism of CH with thyroid in situ in eligible children suspected of dyshormonogenic defect and to verify the adequacy of the treatment schedules. Thirty out of thirty-one children were affected with permanent hypothyroidism and only one child was euthyroid at revaluation (transient CH). I-123 scintigraphy with perchlorate discharge test showed 13 children with iodine organification defects. In patients without iodine organification defect, analyses of TSH-receptor and PAX8 genes showed an inactivating TSH-receptor gene mutation in one patient. Thyroid hormone organification defect were present only in half of the CH patients with thyroid in situ. A higher prevalence of partial defects of iodine organification than severe or complete forms was found. So far, genetic analyses have provided etiological diagnosis in a limited subset of patients. Some questions remain unanswered concerning the proper treatment of mild and borderline forms of CH

Congenital hypothyroidism with gland in situ: diagnostic re-evaluation

In the past, most congenital hypothyroidism (CH) children with thyroid gland in situ were considered to be affected by hormonogenesis defect. Nowadays, the improved sensitivity of neonatal screening, novel insights into the pathogenic mechanisms and the advances of genetic analyses have reopened the discussion about the etiology of CH with thyroid in situ. We report the etiological re-evaluation of 31 children with thyroid in situ, who had been identified by the CH screening program. The purposes of this re-evaluation were: a) to investigate the definitive diagnosis and pathogenetic mechanism of CH with thyroid in situ in eligible children suspected of dyshormonogenetic defect and b) to verify the adequacy of the treatment schedules. Thirty out of 31 children were affected with permanent hypothyroidism and only one child was euthyroid at re-evaluation (transient CH). Thyroid hormone organisation defects were present in less than half of the CH patients with thyroid in situ (13/30); a higher prevalence of partial defects of iodine organification than severe or complete forms was found. An inactivating TSH-receptor gene mutation was found in only one patient without iodine organification defect. Some questions remain unanswered concerning the adequacy of the schedules of treatment, particularly about the proper treatment of mild and borderline forms of CH

Ctla4 and multiple sclerosis in the Italian population

CTLA4 protein is a receptor molecule that plays a critical role as a negative regulator of the immune response. Therefore, genetic variations in CTLA4 may confer susceptibility to autoimmune diseases such as multiple sclerosis (MS). In order to investigate the association of two CTLA4 polymorphisms (+49 A/G and 12318 C/T) with multiple sclerosis, sporadic MS patients and healthy controls from Italy were genotyped through direct DNA sequencing. Considering single-loci variations, no differences in the allelic and genotypic frequencies between patients and controls were found. However, considering a putative interaction at the two loci, the T/G combination was more frequently observed in patients than in controls. This result suggests that this allelic combination of the CTLA4 polymorphisms may be involved in the susceptibility to MS in the Italian population