MON-500 Cell Adhesion Molecules mRNA Expression in Thyroid Tumors

Thyroid cancer biology is extremely diverse. While some cases never progress clinically or do so indolently, others evolve aggressively and may even lead to death. Cell adhesion molecules are glycoproteins present in the cell membrane and play an important role in inflammatory and neoplastic diseases by recruiting immune cells to these sites. The aim of the present study was to investigate the role of mRNA expression of SELL, ICAM1 and ITGAL in thyroid tumors and their relationship with lymphocyte infiltration. We evaluated by RT-qPCR technique 191 thyroid nodules including 97 benign (79 females, 17 males; 49.8±12.5 years old) and 94 malignant (71 females, 23 males; 48.3±15.5years old) cases. Clinical and pathology data were obtained from 47 goiters; 50 follicular adenomas (FA); 74 papillary thyroid carcinomas (PTC), including: 29 classic papillary thyroid carcinomas (CPTC), 21 follicular variant of PTC (FVPTC), 12oxifilic variant of PTC (OVPTC), 12 tall cell papillary thyroid carcinomas (TCPTC); and 20 follicular thyroid carcinomas (FTC). All patients were managed according to a standard protocol based on current guidelines and followed-up for 78.7±54.2 months. SELL was more expressed in malignant (0.85±1.54 UA) than in benign (0.54±0.71 UA, p=0.0027) nodules. The same occurred with ICAM1 (0.99±1.41 vs. 0.46±0.85, p=0.0001), but not with ITGAL gene expression (1.04±1.63 vs. 0.76±1.21, p=0.2131). In addition, the expression of SELL was different when we compared PTC with FA (0.94±1.62 UA vs. 0.47±0.72 UA, p=0.0018) and FTC with FA (0.82±2.38 UA vs. 0.47±0.72 UA, p=0.0078). ICAM1 expression was lower in goiters (0.46±0.90 UA) when compared with PTC (0.93±1.22 UA, p=0.0030) and FTC (1.03±3.30 UA, p=0.0207). Higher expression of ICAM1 (1.16±3.04 UA vs. 0.52±0.96 UA, p=0.0064) and ITGAL (1.17±1.54 UA vs. 0.49±1.39 UA, p=0.0244) was observed in tumors with lymphocyte infiltrate. Also, ITGAL gene expression was higher in tumors that had distant metastasis at diagnosis (1.53±2.18 UA vs. 0.57±1.10 UA, p=0.0217). We were not able to demonstrate any association between any of the investigated molecules and patients’ outcome. In conclusion, our data suggest that cell adhesion molecules may play an important role in neoplastic thyroid cells proliferation. In addition, our findings show that gene expression of SELL and ICAM1 may assist in the histological characterization of follicular patterned thyroid nodules.

MON-504 VEGFA and VEGFR2 Expression in Different Histological Types of Thyroid Nodules: Could Immunohistochemistry Have a Clinical Utility?

Vascular endothelial growth factors (VEGFs) are a family of proteins involved in several elements that play an important role in the development of blood vessels. Besides acting in angiogenesis, VEGFA has important roles in chemotaxis, for macrophages and granulocytes, and vasodilation. VEGFA binds to VEGFR2, that acts on the MAPK and PI3K pathways, fundamental pathways for thyroid carcinogenesis. In order to assess the expression of VEGFA and VEGFR2, in different thyroid nodules, we used a Tissue MicroArray including 91 benign (74 females, 16 males, 49.84±12.65years old) and 125 malignant thyroid nodules (97 females, 28 males, 46.57±14.87 years old). Clinical and pathology data were obtained from 47 goiters; 43 follicular adenomas (FA) and a total of 104 papillary thyroid carcinomas (PTC), including 35 classic papillary thyroid carcinomas (CPTC), 30 follicular variant of PTC (FVPTC), 25 oxifilic variant of PTC (OVPTC), 14 tall cell papillary thyroid carcinomas (TCPTC); and 21 follicular thyroid carcinomas (FTC). All patients were managed according to a standard protocol based on current guidelines and followed-up for 116.9±70.8 months. VEGFA protein expression did not differentiate benign from malignant thyroid nodules. However, VEGFA was more frequently expressed in the less differentiated thyroid tissues. In fact, 95.8% of the FTC had positive expression. On the contrary, the intensity of this protein expression was progressively lower according to the process of cellular dedifferentiation (Goiter: 21.4%; FA: 16.3%; PTC: 8.7% and FTC: 0.0%; x2 = 0.031). There was no difference in VEGFR2 expression between malignant and benign nodules (x2= 0.108), but this protein showed more intense expression in tissues that also presented Hürthle cells (x2 <0.0001). We were not able to find any correlation, neither of VEGFA nor with VEGFR2 expression, and any other feature of aggressiveness, including invasion, metastasis, lymph node metastasis, and distant metastasis. We conclude that VEGFA and VEGFR2 expression may help identify less differentiated tumors and the analysis of a larger cohort may prove the clinical utility of these markers.

Gene expression of thyroid-specific transcription factors may help diagnose thyroid lesions but are not determinants of tumor progression

PURPOSE

The role of thyroid-specific transcription factors in thyroid malignancy is still poorly understood, so we investigate thyroid-specific transcription factors gene expression both in benign and in malignant thyroid nodules, aiming to study a possible clinical utility of these molecules.

METHODS

We quantified TTF-1, FOXE1 and PAX8 mRNA levels, relating their expression to diagnostic and prognostic features of thyroid tumors. RNA was extracted from 4 normal thyroid tissues, 101 malignant [99 papillary thyroid carcinomas (PTC) and 2 anaplastic thyroid carcinomas] and 99 benign thyroid lesion tissues [49 goiter and 50 follicular adenomas (FA)].

RESULTS

Levels of mRNA of both FOXE1 (P < 0.0001) and PAX8 (P < 0.0001) genes, but not TTF-1 (P = 0.7056), were higher in benign than in malignant thyroid lesions. FOXE1 was able to identify malignant nodules with 75.8 % sensitivity, 76.1 % specificity, 75.8 % positive predictive value, 76.1 % negative predictive value and 75.9 % accuracy. PAX8 was able to identify malignancy with 60.6 % sensitivity, 81.1 % specificity, 76.9 % positive predictive value, 66.4 % negative predictive value and 70.6 % accuracy. Both FOXE1 and PAX8 gene expression patterns were also able to differentiate FA from the follicular variant of PTC-FVPTC. However, the investigated gene expression was neither associated with any clinical feature of tumor aggressiveness nor associated with recurrence or survival.

CONCLUSIONS

We suggest that FOXE1 and PAX8 gene expression patterns may help to diagnose thyroid nodules, identifying malignancy and characterizing follicular-patterned thyroid lesions, but are not determinants of thyroid tumor progression.

Polymorphisms of cell cycle control genes influence the development of sporadic medullary thyroid carcinoma

BACKGROUND

The role of key cell cycle regulation genes such as, CDKN1B, CDKN2A, CDKN2B, and CDKN2C in sporadic medullary thyroid carcinoma (s-MTC) is still largely unknown.

METHODS

In order to evaluate the influence of inherited polymorphisms of these genes on the pathogenesis of s-MTC, we used TaqMan SNP genotyping to examine 45 s-MTC patients carefully matched with 98 controls.

RESULTS

A multivariate logistic regression analysis demonstrated that CDKN1B and CDKN2A genes were related to s-MTC susceptibility. The rs2066827*GT+GG CDKN1B genotype was more frequent in s-MTC patients (62.22%) than in controls (40.21%), increasing the susceptibility to s-MTC (OR=2.47; 95% CI=1.048-5.833; P=0.038). By contrast, the rs11515*CG+GG of CDKN2A gene was more frequent in the controls (32.65%) than in patients (15.56%), reducing the risk for s-MTC (OR=0.174; 95% CI=0.048-0.627; P=0.0075). A stepwise regression analysis indicated that two genotypes together could explain 11% of the total s-MTC risk. In addition, a relationship was found between disease progression and the presence of alterations in the CDKN1A (rs1801270), CDKN2C (rs12885), and CDKN2B (rs1063192) genes. WT rs1801270 CDKN1A patients presented extrathyroidal tumor extension more frequently (92%) than polymorphic CDKN1A rs1801270 patients (50%; P=0.0376). Patients with the WT CDKN2C gene (rs12885) presented larger tumors (2.9±1.8 cm) than polymorphic patients (1.5±0.7 cm; P=0.0324). On the other hand, patients with the polymorphic CDKN2B gene (rs1063192) presented distant metastases (36.3%; P=0.0261).

CONCLUSION

In summary, we demonstrated that CDKN1B and CDKN2A genes are associated with susceptibility, whereas the inherited genetic profile of CDKN1A, CDKN2B, and CDKN2C is associated with aggressive features of tumors. This study suggests that profiling cell cycle genes may help define the risk and characterize s-MTC aggressiveness.

Genes of detoxification are important modulators of hereditary medullary thyroid carcinoma risk

CONTEXT

Different inherited profiles of genes involved in cellular mechanisms of activation and detoxification of carcinogenic products can provide specific protection or determine the risk for cancer. Low-penetrance polymorphic genes related to the biotransformation of environmental toxins have been associated with susceptibility to and the phenotype of, human tumours.

OBJECTIVE

To investigate the role of germline inheritance of polymorphisms in CYP1A2*F, CYP1A1 m1, GSTP1, NAT2 and TP53 genes in hereditary medullary thyroid carcinoma (HMTC) patients.

DESIGN

This study was developed in University of Campinas (Unicamp).

PATIENTS

We studied 132 patients with HMTC, 88 first-degree relatives of HMTC patients and 575 control individuals.

MEASUREMENTS

All patients with MTC and their relatives were sequenced for the RET gene and five genes were genotyped using TaqMan(®) system.

RESULTS

We observed that the inheritance of CYP1A2*F (OR = 2·10; 95% CI = 1·11-3·97; P = 0·022), GSTP1 (OR = 4·41; 95% CI = 2·47-7·88; P < 0·001) and NAT2 (OR = 2·54; 95% CI = 1·16-5·58; P = 0·020) variants increased the risk for HMTC. In addition, multiple regression analysis showed that the inheritance of GSTP1 polymorphisms was associated with the diagnosis in older patients (B = 8·0229; 95% IC = ± 5·5735; P = 0·0054). Concerning the group of HTMC relatives, CYP1A2*F (OR = 2:40; 95% CI = 1·19-4·86; P = 0·015), CYP1A1 m1 (OR = 2·79; 95% CI = 1:04-7·51; P = 0·042), GSTP1 (OR = 2·86; 95% IC = 1·53-5·32; P < 0·001) and NAT2 (OR = 2·25; 95% IC = 1·20-4·22; P = 0·012) were associated with HMTC risk.

CONCLUSIONS

We have demonstrated that the inheritance of specific genes determining the individual response to environmental toxins may contribute to the risk and phenotypic variability that exists in patients with HMTC. Moreover, we identified a group at risk in relatives of HMTC patients.

Obesity and excess protein and carbohydrate consumption are risk factors for thyroid cancer

Conflicting data concerning the association between obesity and differentiated thyroid cancer (DTC) may be attributed to the lack of records showing dietary intake and inadequate evaluation of nutrient composition. We evaluated 115 DTC patients carefully paired with 103 healthy control individuals by using a structured questionnaire, including a 24-h recordatory during 3 days, to investigate calorie intake and macronutrient (proteins, carbohydrates, and lipids) composition of the diet. We observed that excess weight (body mass index > 25 kg/m(2)) increased individual susceptibility to DTC [odds ratio (OR) = 3.787; 95% confidence interval (CI) = 1.115-6.814; P < 0.0001). This augmented risk was evident in women (OR = 1.925; 95% CI = 1.110-3.338; P = 0.0259) but not in men (P = 0.3498). Excess calorie intake was more frequent in patients with DTC than in controls (OR = 5.890; 95% CI = 3.124-11.103; P < 0.0001), and both excess protein (OR = 4.601; 95% CI = 1.634-12.954; P = 0.0039) and carbohydrate (OR = 4.905; 95% CI = 2.593-9.278; P < 0.0001) consumption were associated with an increased risk of DTC, contrarily to lipid/fiber intake and physical activity (P = 0.894 and 0.5932, respectively). In conclusion, our data indicate that overweight and risk of DTC are associated with higher protein and carbohydrate consumption than the rates recommended by the World Health Organization. The nutritional orientation should be part of preventive strategy targets designed to combat the increasing incidence of both obesity and DTC.

Evidence that polymorphisms in detoxification genes modulate the susceptibility for sporadic medullary thyroid carcinoma

AIM

Polymorphic low-penetrance genes have been consistently associated with the susceptibility to a series of human tumors, including differentiated thyroid cancer.

METHODS

To determine their role in medullary thyroid cancer (MTC), we used TaqMan SNP method to genotype 47 sporadic MTC (s-MTC) and a control group of 578 healthy individuals for CYP1A2*F, CYP1A1m1, GSTP1, NAT2 and 72TP53. A logistic regression analysis showed that NAT2C/C (OR=3.87; 95% CI=2.11-7.10; P=2.2×10(-5)) and TP53C/C genotypes (OR=3.87; 95% CI=1.78-6.10; P=2.8×10(-4)) inheritance increased the risk of s-MTC. A stepwise regression analysis indicated that TP53C/C genotype contributes with 8.07% of the s-MTC risk.

RESULTS

We were unable to identify any relationship between NAT2 and TP53 polymorphisms suggesting they are independent factors of risk to s-MTC. In addition, there was no association between the investigated genes and clinical or pathological features of aggressiveness of the tumors or the outcome of MTC patients.

CONCLUSION

In conclusion, we demonstrated that detoxification genes and apoptotic and cell cycle control genes are involved in the susceptibility of s-MTC and may modulate the susceptibility to the disease.

Usefulness of HBME-1, cytokeratin 19 and galectin-3 immunostaining in the diagnosis of thyroid malignancy

AIMS

To investigate the usefulness of immunohistochemical expression and immunolocalization of a panel of thyroid malignancy markers including HBME-1, cytokeratin (CK) 19 and galectin-3.

METHODS AND RESULTS

We evaluated 170 thyroid lesions including 148 neoplastic lesions [84 papillary carcinomas (PC), 38 follicular carcinomas (FC), 18 follicular adenomas, one hyalinizing trabecular tumour, five medullary carcinomas, two anaplastic carcinomas] and 22 non-neoplastic lesions (12 adenomatous nodules and 10 Hashimoto's thyroiditis). HBME-1, galectin-3 and CK 19 were expressed in 94%, 72.6%, 72.6% of PCs and in 63%, 21%, 21% of FCs. The three markers were mostly negative in all normal tissues. Although the most helpful marker in terms of sensitivity and specificity for the follicular variant of PC and for FC diagnosis was HBME-1, when we consider the differentiation between cases of follicular variant of papillary carcinoma (FVPC) and FC or adenoma, in terms of percentage of positive cells, galectin-3 and CK 19 were more relevant.

CONCLUSIONS

HBME-1 is the most sensitive marker for thyroid malignancy but the three markers may be useful in specific cases. This panel of markers is useful to differentiate the follicular patterned lesions, with special reference to the FVPC.

GSTO polymorphism analysis in thyroid nodules suggest that GSTO1 variants do not influence the risk for malignancy

A new class of glutathione S-transferase enzymes named omega (GSTO) has been recently identified and shown to be expressed in a wide range of human tissues. A genetic polymorphism of the GSTO1 gene causing an alanine-to-aspartate (A140D) substitution in amino acid 140 produces a variant with lowered enzyme activities in the biotransformation of inorganic arsenic, a common contaminant of drinking water in many regions of the world and a well-known carcinogen. In order to investigate the role of GSTO1 inheritance pattern on thyroid cancer risk we used a polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP)-sequencing approach to compare the genotypes of 173 (87 women, 86 men; 18-81 years old; 47+/-18 years old) healthy control individuals with those of 145 patients with thyroid nodules (84 women, 61 men; 17-81 years old; 49+/-14 years old) including 17 follicular carcinomas, 76 papillary carcinomas, 21 follicular adenomas and 31 multinodular goiters. The incidence of GSTO1 variants was similar in the control population and population with the benign and malignant nodules. There was no association between genotype and the patients' clinical features, tumour parameters of aggressiveness at diagnosis or behaviour during follow-up. We conclude that GSTO1 variants do not influence the risk for thyroid nodules or their pathologic and clinical characteristics.