c-KIT receptor expression is strictly associated with the biological behaviour of thyroid nodules

<p>Abstract</p> <p>Background</p> <p>A large amount of information has been collected on the molecular tumorigenesis of thyroid cancer. A low expression of c-KIT gene has been reported during the transformation of normal thyroid epithelium to papillary carcinoma suggesting a possible role of the gene in the differentiation of thyroid tissue rather than in the proliferation. The initial presentation of thyroid carcinoma is through a nodule and the best way nowadays to evaluate it is by fine-needle aspiration (FNA). However many thyroid FNAs are not definitively benign or malignant, yielding an indeterminate or suspicious diagnosis which ranges from 10 to 25% of FNAs. BRAF mutational analysis is commonly used to assess the malignancy of thyroid nodules but unfortunately it still leaves indeterminate diagnoses. The development of molecular initial diagnostic tests for evaluating a thyroid nodule is needed in order to define optimal surgical approach for patients with uncertain diagnosis pre- and intra-operatively.</p> <p>Methods</p> <p>In this study we extracted RNA from 82 FNA smears, 46 malignant and 36 benign at the histology, in order to evaluate by quantitative Real Time PCR the expression levels of c-KIT gene.</p> <p>Results</p> <p>We have found a highly preferential decrease rather than increase in transcript of c-KIT in malignant thyroid lesions compared to the benign ones. To explore the diagnostic utility of c-KIT expression in thyroid nodules, its expression values were divided in four arbitrarily defined classes, with class I characterized by the complete silencing of the gene. Class I and IV represented the two most informative groups, with 100% of the samples found malignant or benign respectively. The molecular analysis was proven by ROC (receiver operating characteristic) analysis to be highly specific and sensitive improving the cytological diagnostic accuracy of 15%.</p> <p>Conclusion</p> <p>We propose the use of BRAF test (after uncertain cytological diagnosis) to assess the malignancy of thyroid nodules at first, then the use of the c-KIT expression to ultimately assess the diagnosis of the nodules that otherwise would remain suspicious. The c-KIT expression-based classification is highly accurate and may provide a tool to overcome the difficulties in today's preoperative diagnosis of thyroid suspicious malignancies.</p

Loss of c-KIT expression in thyroid cancer cells

Papillary thyroid carcinoma is the most frequent histologic type of thyroid tumor. Few studies investigated the role of c-KIT expression in thyroid tumors, suggesting a role for this receptor and its ligand in differentiation and growth control of thyroid epithelium and a receptor loss following malignant transformation. We investigated and correlated c-KIT expression levels and two known markers of thyrocytes differentiation, PAX8 and TTF-1, in malignant and benign cytological thyroid samples. Moreover, we performed functional studies on human papillary thyroid carcinoma cell line to associated c-KIT expression to thyrocytes differentiation and tumor proliferation. c-KIT and PAX8 expression resulted higher in benign samples compared to the malignant ones, and the expression levels of these two genes were significantly correlated to each other. We also observed that c-KIT overexpression led to an increase of PAX8 expression level together with a decrease of proliferation. Furthermore, c- KIT overexpressing cells showed a regression of typical morphological features of malignancy. Taken together these results suggest that c-KIT could be involved in the differentiation of thyroid cells and in tumor progression

Energy Resolution Performance of the CMS Electromagnetic Calorimeter

The energy resolution performance of the CMS lead tungstate crystal electromagnetic calorimeter is presented. Measurements were made with an electron beam using a fully equipped supermodule of the calorimeter barrel. Results are given both for electrons incident on the centre of crystals and for electrons distributed uniformly over the calorimeter surface. The electron energy is reconstructed in matrices of 3 times 3 or 5 times 5 crystals centred on the crystal containing the maximum energy. Corrections for variations in the shower containment are applied in the case of uniform incidence. The resolution measured is consistent with the design goals

Cancer astrocytes have a more conserved molecular status in long recurrence free survival (RFS) IDH1 wild-type glioblastoma patients: New emerging cancer players

Glioblastoma is a devastating disease that despite all the information gathered so far, its optimal management remains elusive due to the absence of validated targets from clinical studies. A better clarification of the molecular mechanisms is needed. In this study, having access to IDH1 wild-type glioblastoma of patients with exceptionally long recurrence free survival (RFS), we decided to compare their mutational and gene expression profile to groups of IDH1 wild-type glioblastoma of patients with shorter RFS, by using NGS technology. The exome analysis revealed that Long-RFS tumors have a lower mutational rate compared to the other groups. A total of 158 genes were found differentially expressed among the groups, 112 of which distinguished the two RFS extreme groups. Overall, the exome data suggests that shorter RFS tumors could be, chronologically, in a more advanced state in the muli-step tumor process of sequential accumulation of mutations. New players in this kind of cancer emerge from the analysis, confirmed at the RNA/DNA level, identifying, therefore, possible oncodrivers or tumor suppressor genes

Analysis of shared common genetic risk between amyotrophic lateral sclerosis and epilepsy

Because hyper-excitability has been shown to be a shared pathophysiological mechanism, we used the latest and largest genome-wide studies in amyotrophic lateral sclerosis (n = 36,052) and epilepsy (n = 38,349) to determine genetic overlap between these conditions. First, we showed no significant genetic correlation, also when binned on minor allele frequency. Second, we confirmed the absence of polygenic overlap using genomic risk score analysis. Finally, we did not identify pleiotropic variants in meta-analyses of the 2 diseases. Our findings indicate that amyotrophic lateral sclerosis and epilepsy do not share common genetic risk, showing that hyper-excitability in both disorders has distinct origins

ANALYTICAL AND CLINICAL VALIDATION OF BIOMARKERS FOR NON INVASIVE EARLY DIAGNOSIS OF BLADDER CANCER

Bladder cancer (BC) is the seventh most common cancer worldwide and its incidence has increased in the last 10 years. It is predominantly a disease of older males, with a median age at presentation of 60-65 years. There are geographical variations in incidence, in Europe the highest incidence rates for men are in northern Italy, Spain and Geneva, Switzerland. The etiology is well defined, with the most common association being cigarette smoking and other factors including exposure to dyes and some industrial solvents, exhaust fumes. Nearly 80% of new cases originate from diffuse flat hyperplasia also referred to as low-grade intraurothelial neoplasia. They are typically of low histologic grade, growing as superficial papillary protrusions, and have high propensity for recurrence but they practically never invade the bladder wall or metastasize. The remaining 20% of tumors are non-papillary and develop from severe displasia or carcinoma in situ (CIS), also termed high-grade intraurothelial neoplasia. About 10-15% of low grade superficial papillary tumors progress to invade the bladder wall and may metastasize [1]. Both types of cancer are significant problem for public health: papillary tumors are not usually life threatening but because of their high recurrence rate, they contribute to bladder cancer’s rank as most expensive in terms of clinical management. Although about half of muscle-invasive tumors do initially respond cisplatin-based chemotherapy, the development of drug resistance is the major problem, and the disease progression in resistant tumors is rapid and uniformly fatal [2]. Many factors, such as chromosomal anomalies, genetic polymorphisms, genetic and epigenetic alterations, contribute to tumorigenesis and progression of bladder cancer. Several authors have reported that the detection of single genetic abnormalities can improve diagnosis and surveillance of the disease Different genes are well known to be involved independently in the development of BC, leading to loss of cell proliferation control (genes in FGFR3-p53 pathway), apoptosis resistance (i.e. Survivn) and promoting Epithelial Mesenchimal Transition (EMT) (i.e.: CK19, CK20, E cadherin and CD44). MicroRNAs (miRNAs) are part of a class of small ribonucleic acid (RNAs). They are important regulatory molecules, involved in several cell processes, such as developmental timing, stem cell division and apoptosis. Dysregulated miRNAs have been identified in several human malignancies, including bladder cancer tissue samples, and may confer a “tumour signature” that can be exploited for diagnostic purposes. To determine whether there is a correlation between the genetic profile and the histo-pathological feature of BC in an Italian population, we genetically characterized 66 Italian patients affected by BC, analyzing both TP53 and FGFR3 mutational status, and CK19-20, E cadherin, Survivin and CD44 gene expression levels. We report also a prospective pilot study investigating the diagnostic ability of a two miRNAs in voided urine samples collected from patients with bladder cancer just prior to bladder tumour resection Survivin was significantly over-expressed (p=0.019) in invasive tumors related to CK20 down-regulation (p=0.025). Using multivariate analysis we observed a significant positive relationship between CK19 and CK20 (p=0.0006), a significant association between E cadherin and CK20 in both High Grade (HG) and Low Grade (LG) tumors (p=0.0064 and p=0.0000, respectively) and a strong positive association between Survivin and CD44 (p= 0.0000) only in HG tumors. TP53 and FGFR3 mutations showed a heterogenic distribution. Gene expression data obtained by RT-PCR on CD44, E-cadherin and Survivin in urine sediments don’t show any significant value in discriminating BC patients from healthy donor group. On the contrary, the two miRNAs of interest were significantly up regulated in urine of BC patients than in healthy controls. Moreover, different statistical methods, like Discriminant Analysis (StatGraphics software) and Artificial Neural Network (ANN), showed a really strong predictive value (around 89% and 83% respectively) using miRNA expression value together in discriminating BC patents from healthy group. Taken together, our findings on TP53 and FGFR3 mutational status support the well-known genetic heterogeneity of BCs. However our results put in evidence the role of CD44, CK20, CK19 and Survivin on invasiveness ability and apoptosis resistance in HG tumors. The results on miRNA analysis provide rationale for further studies on validation of candidate miRNAs in voided urine and may potentially lead to the development of a non-invasive and sensitive test for bladder cancer diagnosis and recurrence surveillance

Abstract B39: Exome sequencing in primary melanoma identifies novel drivers of melanoma progression

Abstract Melanoma is the most malignant and lethal among skin cancers, due to its high infiltration and invasion ability and resistance to therapy. Whereas early stages melanoma can be cured in the majority of cases by surgical excision, metastatic melanoma is a highly lethal condition. The most frequent known oncogenic mutation in melanoma is BRAF-V600E and several full exome sequencing studies have revealed numerous other alterations (Wei et al, 2011; Nikolaev et al, 2011; Stark et al, 2011; Krauthammer et al, 2012). A crucial issue in understanding melanoma progression is to identify which mutations are specifically involved in making an individual melanoma competent for metastatic spread. It is well established that this behavior is highly correlated with histological features, such as the thickness of the primary tumor and the mitotic index. Here we performed full exome sequencing of 5 thin (&amp;lt;1mm in thickness) and 5 thick (&amp;gt;4mm in thickness) primary melanomas compared to matched-normal DNA. We confirmed recurrent somatic mutations in known melanoma-related genes, including BRAF, c-KIT, EGFR, PPP6C, MLL3 and several components of the glutamate signaling. In addition, we discovered mutations in genes not previously linked to this tumor, such as CSMD1, FGFR4 and components of the Hedgehog (HH) signaling pathway. In particular, in a thick melanoma we found an novel activating mutation in the transcription factor GLI1, one of the final effectors of the HH signaling. Notably, in the only 3 thick melanomas that produced metastasis, we identified candidate metastasis-driving mutations in six genes (ADAMTS6, ADAMTS7, CHD9, MLL3, NALCN and TSC2). Interestingly, we identified several regions of focal somatic copy-number alterations (SCNAs) that were altered at significantly higher frequency in thick compared to thin melanomas. Several gene families are comprised among these regions of focal SCNAs, including components of Notch, HH and Wnt/ß-catenin signaling pathways, BRAF, c-MYC and its cofactor PIM1, several ADAMs, EGFR and the HOX genes. Our preliminary results identify potential drivers of melanoma progression, enhancing our understanding of the genomic complexity underlying melanoma. Citation Format: Valentina Montagnani, Matteo Benelli, Alessandro Apollo, Gianni Gerlini, Lorenzo Borgognoni, Barbara Stecca. Exome sequencing in primary melanoma identifies novel drivers of melanoma progression. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Melanoma: From Biology to Therapy; Sep 20-23, 2014; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(14 Suppl):Abstract nr B39.</jats:p