RAP1GAP Functions as a Tumor Suppressor Gene and Is Regulated by DNA Methylation in Differentiated Thyroid Cancer

Inactivation of tumor suppressor genes, such as RAP1GAP, by hypermethylation of their regulatory region can give rise to thyroid tumors. The aim of this study was to investigate the expression of the RAP1GAP gene and the DNA methylation patterns of its CpG74a, CpG74b, and CpG24 in an Iranian population with differentiated thyroid cancer (DTC). In this study, 160 individuals who underwent thyroidectomy in the Tehran Erfan Hospital between 2018 and 2020 were selected. DNA methylation patterns of selected CpG islands (CpG74a, CpG74b, and CpG24) were determined using methylation-specific PCR. The mRNA expression and protein level of -RAP1GAP were also evaluated. SW1736 and B-CPAP cells were treated with 5-aza-2'-deoxycytidine (5-Aza) to demethylate these regions. The hypermethylation rates of CpG74a and CpG24 in DTC samples were significantly higher than in the control. The mRNA expression and protein level of -RAP1GAP were significantly decreased in the DTC group. In the DTC group, hypermethylation in CpG74a was correlated with decreasing RAP1GAP expression (R2: 0.34; p = 0.043). CpG74a with a specificity of 86.4% has significant prediction power to distinguish between DTC and normal thyroid tissues. Additionally, hypermethylation of CpG74a was significantly associated with higher tumor stages (stage III-IV: 77%; stage I-II: 23%; p = 0.012). Increasing expression of RAP1GAP after demethylation with 15 µM of 5-Aza was observed in both cell lines. These results indicate that DNA hypermethylation in CpG74a can be considered as an epigenetic biomarker in DTC.

A survey of the incidence of dyslipidemia and its components in people over 20 years old in Ahvaz: A cohort study 2009-2014

INTRODUCTION

Dyslipidemia is one of the major risk factors for atherosclerosis and the main cause of death in the developing and developed countries. In this cohort study, the incidence of dyslipidemia and its components have been studied among individuals over 20 years old in Ahvaz, southwest of Iran.

MATERIALS AND METHODS

The Phase 1 of this study was conducted on the prevalence of Metabolic syndrome and its related factors by Diabetes Research Center in 2009. The target population included individuals over 20 years old who were selected using cluster sampling in Ahvaz health centers. In the second phase of the study, 5 years later in 2014, subjects were again recalled by health centers. Questionnaires, anthropometric indices and measurements were repeated similar to Phase 1. The blood sample was taken from everyone after 12h of fasting and then the factors (Chol, TG, HDL) were measured.

RESULTS

The cumulative incidence of dyslipidemia obtained 60.7% (males 56.7% and females 64.8%). lipid profile {HDL, Triglycerides and Cholesterol had changes in their means(a significant reduction in the mean about 10, 22.25 and 13 units respectively) between baseline and 5 years later. Waist circumference here associated with incidence of high LDL and high chol, also sex and High LDL 'educational level and daily consumption of vegetables were associated with incidence of low HDL and dyslipidemia respectively.

CONCLUSION

Age, educational level and daily intake of fruits and vegetables were effective variables on incidence of dyslipidemia. According to various studies, LDL and HDL levels in different regions of Iran, seems to be influenced by factors such as climate, nutrition and activity levels.

Prevalence, awareness and risk factors of diabetes in Ahvaz (South West of Iran)

INTRODUCTION

This study was designed to assess the prevalence of diabetes in people aged over 20 years in Ahvaz, Iran.

MATERIALS AND METHODS

The study population was chosen by cluster sampling. A checklist included: age, sex, weight, height, blood pressure, waist circumference, educational level, smoking status and previous history of diabetes was completed for each patient. Fasting Plasma Glucose (FPG) ≥126mg/dl and/or oral hypoglycemic treatment and/or insulin consumption was defined as diabetes, FPG=100-125mg/dl as Impaired Fasting Glucose (IFG) and FPG <100mg/dl as normal.

RESULTS

Study population was 944 persons. Mean age of population was 42.2±14 years. Diabetes was detected in 15.1% of population. Only 40.4% of cases were aware of their disease. Diabetes was detected in 14.7% of female and 15.7% of male participants. Diabetes was related to age, waist circumference, family history of diabetes, hypertension, waist to hip ratio, educational level, marital status, serum triglyceride, cholesterol and body mass index (BMI) in both genders. But by using logistic regression analysis, age, family history of diabetes, hypertension, hypertriglyceridemia, and marital status had significant effect on diabetes.

CONCLUSION

This study showed that using FPG criteria or current medication 15.1% of this population had diabetes and about 60% of patients were unaware of their disease. Age, hypertension, family history of diabetes, hypertriglyceridemia and marital status are the risk factors of diabetes in Ahvaz population. IFG have high prevalence and diabetes screening should be intensified in this population.

Ultrasonographic characteristics and follow-up in post-partum thyroiditis

Post-partum thyroiditis (PPT) is an autoimmune disorder of the thyroid gland, which occurs in the first year after parturition. This study was designed to evaluate sonographic characteristics in a group of PPT patients in Tehran. The study group consisted of 119 PPT patients and 97 normal post-partum women as the control group. Physical examination of thyroid and ultrasonography were carried out monthly in PPT patients until remission for up to 12 months post-partum and 65 patients were followed-up until the end of the study. Visible goiter was detected in 21.8% of patients and 6.7% of the control group (p < 0.001). Hypoechogenecity in thyroid sonography was present in 98.5% of patients and 7% of the control group (p < 0.001). Initially mean thyroid volume in PPT patients was found to be 77% more than that of the control group. After remission, mean thyroid volume decreased by 25% in PPT patients. At 12 months after delivery, only 6 patients had abnormal thyroid function tests, while 4 patients with TSH > 10 mU/I still showed hypoechogenicity in thyroid sonography. In conclusion, sonography may be recommended as an adjuvant to laboratory tests in evaluation of PPT patients.

Prevalence and characteristics of postpartum thyroid dysfunction in Tehran

OBJECTIVE

To determine the prevalence of postpartum thyroiditis (PPT), one of the autoimmune disorders of the thyroid which usually occurs in women in the first year after parturition. PPT presents with periods of transient thyrotoxicosis and hypothyroidism, in many cases resulting in permanent hypothyroidism.

DESIGN

The study involved 1040 mothers who had contacted five health centers in Tehran for vaccination of their children.

METHODS

Signs and symptoms of hypothyroidism and thyrotoxicosis, and the presence of goiter (using the World Health Organization classification), were sought. Serum T3, T4, TSH, anti-TPO and anti-Tg antibodies were measured at 3, 4.5, 6 and 9 months after parturition. In those with hypothyroidism or thyrotoxicosis and a matched group of normal women, thyroid sonography was performed.

RESULTS

The prevalence of thyroiditis was 11.4%. Hypothyroidism and thyrotoxicosis occurred in 68 and 42 mothers respectively. Nine had thyrotoxicosis followed by hypothyroidism. There was one case of Graves' disease. Out of 68 hypothyroid patients, 33 women underwent treatment with levothyroxine (because of the severity of symptoms) for 12 months. Six women showed increased TSH at 6 weeks after discontinuation of thyroxine. Stage II goiter (World Health Organization classification) were observed in 21.8% of patients and in 6.7% of pospartum euthyroid women (P<0.001). Positive anti-TPO was found in 61.5% of patients and in 19% of the control group; positive anti-Tg was found in 58% of patients and in 6% of the control group (P<0.001). Sonographic changes were observed in 96% of the patients and in 7% of the control group (P<0.001). There was no significant correlation between the occurrence of thyroiditis and parity, the age of the mother, a previous history of thyroid disease in the patient or family, breast-feeding, or the gender of the child.

CONCLUSION

The results of this study show a high prevalence of PPT in Tehranian women. This may be due to the length and frequency of follow-up and/or the transition from low to adequate iodine intake. The major difference with respect to other studies is the low frequency of the biphasic form of PPT.