Leptin: A Correlated Peptide to Papillary Thyroid Carcinoma?

Introduction. Leptin as an adipose-tissue-related peptide hormone contributes to the control of food intake, energy expenditure, and other activities such as cell proliferation. Therefore, association of leptin level with thyroid cancer has been suggested recently. Considering that thyroid cancer is the most common endocrine cancer, the aim of this study was evaluation of leptin levels in thyroid cancer. Materials and Methods. 83 patients with papillary thyroid cancer (35 males and 48 females) with 90 healthy persons as control group (40 male and 50 females) were selected. serum thyroxine, thyrotropin, and leptin levels were determined in both groups. As a body fat tissue affects leptin level, so height and weight were measured and body mass index was calculated too. Results. There was no statistically significant difference in age, serum Thyroxine, and Thyrotropin levels. BMI in women was more than in men in both groups. Serum leptin levels in thyroid cancer group were significantly higher than control group (P < 0.05). Conclusion. The results of this study showed an acceptable association between the hormone Leptin levels with papillary thyroid cancer, so it may be considerad as a correlated peptide which may help in the diagnosis or confirmation of thyroid cancer beside in other specific tumor markers

Predominant RET Germline Mutations in Exons 10, 11, and 16 in Iranian Patients with Hereditary Medullary Thyroid Carcinoma

Medullary thyroid carcinoma occurs in both sporadic (75%) and hereditary (25%) forms. The missense mutations of RET proto-oncogene in MTC development have been well demonstrated. To investigate the spectrum of predominant RET germline mutations in exons 10, 11, and 16 in hereditary MTC in Iranian population, 217 participants were included. Genomic DNAs were extracted from the leukocytes using the standard Salting Out/Proteinase K method. Mutation detection was performed through PCR-RFLP and DNA sequencing. In 217 participants, 43 missense mutations were identified in exons 10 (6%), 11 (13%), and 16 (0.9%). Moreover, a novel germline mutation was detected in exon 11 (S686N). Also four different polymorphisms were found in intron 16 in eight patients. The obtained data showed the frequency profile of RET mutations in Iranian individuals with MTC (19.8%). The most frequent mutation in our population was C634G whereas in most population it was C634R. Altogether, these results underline the importance of the genetic background of family members of any patient with MTC

Germline mutation of RET proto-oncogene’s exons 17 and 18 in Iranian medullary thyroid carcinoma patients

Background: Thyroid carcinoma is the most common endocrine malignancy. Medullary thyroid carcinoma (MTC) approximately accounts for 5-10% of all thyroid carcinoma. Nowadays, it is obviously, the mutations in REarranged during transfection (RET) proto-oncogene, especially, mutations in exons 10, 11 and 16 are associated with MTC pathogenesis and occurrence. Thus, early diagnosis of MTC by mutation detection in RET proto-oncogene allows to identify patients who do not have any developed symptoms. The aim of this study was to screening of germline mutations in RET proto-oncogene exons 17 and 18 in MTC patients and their first degree relatives in Iranian population. Methods: In this cross-sectional study, three hundred eleven participates (190 patients, 121 their relatives) were referred to endocrine research center, Shahid Beheshti University of Medical Science during September 2013 until September 2015. The inclusion criteria were pathological and clinical diagnosis. After whole blood sampling, genomic DNA was extracted from peripheral blood leucocytes using the standard Salting Out/Proteinase K method. Nucleotide change detection in exons 17 and 18 was performed using PCR and direct DNA sequencing methods. Results: In this study, twenty missense mutations [CGC>TGC, c.2944C>T, p.Arg982Cys (rs17158558)] which included 16 heterozygote and 4 homozygote mutations were found in codon 982 (exon 18). In the present study, 154 G>A (rs2742236) and 4 C>T (rs370072408) nucleotide changes were detected in exons 18 and intron 17 respectively. There was no mutation in exon 17. Conclusion: It seems that because of arginine to cysteine substitutions in RET tyrosine kinase protein structure and its polyphen score (0.955) and SIFT score (0.01) the mutation in codon 982 (exon 18) could be have pathogenic effects. On the other hands, the mentioned mutation frequency was 6.4% among MTC patients, so this mutation of exon 18 could be checked in genetic screening tests of RET proto-oncogene. Although this needs more study

Plasma levels of calcitonin in medullary thyroid carcinoma patients with and without the RET proto-oncogene mutations in exons 10 and 11

Background: Thyroid carcinoma is the most common endocrine malignancy and approximately accounts 2% of all cancer cases. Medullary thyroid cancer (MTC) is an endocrine tumor with differentiation of Parafollicular or C-cells and is categorized into hereditary or sporadic types. Medullary thyroid carcinoma approximately accounts for 5-10% of all thyroid carcinoma. Germ-line and somatic mutations in exons 10 and 11 RET (Rearranged during Transfection) proto-oncogene are responsible for the occurrence of the familial and sporadic types, respectively. Calcitonin is a key marker in MTC diagnose and has been demonstrated to be highly sensitive for differential diagnosis prognostic assessment, follow-up and evaluation of MTC treatment. The aim of this study was to investigate the relationship between plasma levels of calcitonin in MTC patients with or without RET mutation. Methods: In this cross-sectional study, the population consist of MTC patients who have referred to the endocrine and metabolism research center of Shahid Beheshti University of medical sciences since October 2013 till October 2016. Genomic DNA was extracted from peripheral blood leucocytes using the standard salting out/proteinase K method. Nucleotide change detection in exons 10 and 11 was performed using polymerase chain reaction (PCR) and direct DNA sequencing methods. Participants were then divided into two groups with or without mutation (43 individuals in each group). Plasma calcitonin levels were determined by enzyme-linked immunosorbent assay (ELISA) method in both groups. Results: Evaluation of the level of plasma calcitonin in 43 patients with a molecular mutation in RET proto-oncogene (mean age 31 years) and 43 patients without molecular mutations in RET proto-oncogene (mean age 43 years) were 7.6 pmol/mL and 3.07 pmol/mL respectively. This difference is statistically significant (P=0.0014). Conclusion: Routine measurement of calcitonin has been investigated as a screening method for the diagnosis of medullary thyroid carcinoma patients. Nevertheless, additional data are required to definitely support routine measurement of calcitonin due to the role of RET proto-oncogene

The frequency of G691S/S904S Haplotype of RET proto-oncogene in medullary thyroid carcinoma patients in Iranian population

Background: Medullary thyroid carcinoma (MTC) occurs in both sporadic (75%) and hereditary (25%) forms. The missense mutations of the rearranged during transfection (RET) proto-oncogene in MTC development have been well demonstrated. Several studies have been published that indicate the molecular analysis of RET gene may offer early identification of those patients at high risk to develop MTC and may provide the opportunity for early intervention. The aim of this study was to investigate frequency of G691S/S904S haplotype in MTC patients and their relatives. Methods: From 2004 to 2014, 358 participants were studied, including 213 patients (119 female, 94 male) and 145 their relatives (79 female, 66 male) in cellular and molecular research center of Shahid Beheshti Research Institute for Endocrine Sciences, Tehran, Iran. Genomic DNA was extracted from peripheral blood leucocytes using the standard Salting Out/Proteinase K method. Nucleotide change detection was performed using PCR and direct DNA sequencing methods. The RET mutations and SNPs, sequences were analyzed. Results: According to DNA sequencing results, 189 individuals (119 patients, 70 relatives) had both G691S (rs1799939) missense mutation in exon11 and S904S (rs1800863) synonymous mutation in exon 15 of RET proto-oncogene. The allele frequency of G691S/S904S haplotype was 35.02% in patients and 29.92% in their relatives. Conclusion: The obtained data showed the frequency of G691S/S904S RET gene haplotype among Iranian MTC patients and their relatives. The G691S and S904S nucleotide changes were in complete linkage disequilibrium, so the results were grouped together and referred to as G691S/S904S haplotype. This haplotype are not considered as oncogenic mutations at this time, its functional role should be investigated. Further analysis is needed to demonstrate the association between this haplotype and MTC development

Expression of miR-127, miR-154, and miR-183 in Medullary Thy-roid Carcinoma Tumors

Background: Medullary thyroid cancer (MTC) accounts for 5%–10% of all thyroid cancers, but causes 13% of all thyroid cancer related deaths. MicroRNAs (miRs) have key functions in the development and progression of MTC. Altered expression of some miRs has been reported in many human cancers, including Thyroid cancer. Therefore, we aimed to analyze the expression of miR-154, miR-183 and miR-127 in MTC tumor tissues. Methods: In this case-control study, 15 MTC Formalin-fixed, paraffin-embedded (FFPE) tissue samples and 15 adjacent normal thyroid FFPE tissues, as a control group, were collected from Taleghani, and Loghman Hakim Hospitals, Tehran, Iran since 2005 till 2015. After RNA extraction and cDNA synthesis, the expression of miR-127, miR-154 and miR-183 was measured by quantitative Real-Time Polymerase Chain Reaction (qRT-PCR). Results: Our data showed a significant increase in the expression of miR-127 in MTC samples in comparison with the control group (P<0.05). Although miR-154 and miR-183 expression levels had increase expression in MTC tumors, this change was not statistically significant. Conclusion: The miR-127 could be considered as a prognostic, diagnostic and therapeutic marker for the management of MTC, and it is proposed for further investigation to fully establish the role of this miRNA in MTC

NOL4 is Downregulated and Hyper-Methylated in Papillary Thyroid Carcinoma Suggesting Its Role as a Tumor Suppressor Gen

Background: Thyroid cancer is the fourth most common cancer in the world. Papillary thyroid carcinoma (PTC) accounts for 80% of all types of thyroid neoplasm. Epigenetic alterations such as DNA methylation are known as the main cause of different types of cancers through inactivation of tumor suppressor genes. Objectives: In the present study, the expression and methylation of suggested gene namely nucleolar protein 4 (NOL4) in PTC in comparison to multi nodular goiter (MNG) have been studied. Methods: Forty-one patients with PTC and 38 patients affected by MNG were recruited. Thyroid tissues were obtained during thyroidectomy. RNA and DNA were extracted from thyroid tissues. Quantitative RT-PCR assay was performed for determining the mRNA level of NOL4 while methylation-sensitive high resolution methylation was applied for assessing the methylation status with designing six pairs primers for six regions on gene promoter which were named from NOL4 (a) to NOL4 (f). Results: Methylation assessment of 81 CpG islands in the promoter region of NOL4 gene revealed that NOL4 (f), the nearest region to the start codon, was significantly hypermethylated in PTC cases compared to MNG cases. NOL4 level in PTC cases in comparison with MNG cases were downregulated. The methylation status and mRNA level of NOL4 (f) were associated with age of diagnosis (Age of the patient at the time of diagnosis), lymph node metastasis, and advanced stages of disease. Conclusions: These data suggested an aberrant promoter hyper-methylation of NOL4 in PTC cases may be linked with its downregulation. Therefore, NOL4 gene can be proposed as a potential tumor suppressor gene in PTC tissues