Effect of exposure to PCBs on normal and tumoral human thyroid cells: an in vitro study

• Grant number: 24/09279-2
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: August 01, 2024
• End date: February 28, 2025
• Field of knowledge: Health Sciences - Medicine - Medical Clinics
• Principal Investigator: Caroline Serrano Do Nascimento
• Grantee: Vinicius Gonçalves Rodrigues
• Host Institution: Instituto de Ciências Ambientais, Químicas e Farmacêuticas (ICAQF). Universidade Federal de São Paulo (UNIFESP). Campus Diadema. Diadema , SP, Brazil

Abstract

The thyroid is a classical endocrine gland that synthesizes the thyroid hormones T3 and T4, which are essential for growth, development, and metabolism. Alterations in thyroid function trigger metabolic disorders and other health problems. Thyroid cancer is the most common malignant neoplasm of the endocrine system, with papillary carcinoma being the most frequent. Genetic mutations, such as those in the RET or BRAF genes, are often associated with the development of these tumors. Additionally, exposure to endocrine-disrupting chemicals (EDCs), substances that interfere with hormonal function, has been linked to the development and increased prevalence of thyroid tumors. Among the EDCs, PCBs (polychlorinated biphenyls) are particularly concerning due to their widespread presence in the environment and their association with thyroid dysfunction and carcinogenic effects. Despite being banned in many countries, the Brazilian government has set a deadline of 2025 to eliminate the use of equipment containing PCBs. Our previous in vivo and in vitro studies suggest that PCBs affect the synthesis, secretion, and transport of thyroid hormones, as well as trigger epigenetic changes that dysregulate gene expression in the thyroid. In this context, the present project aims to investigate the effects of PCB exposure on cellular function and the expression of cancer-related markers in normal and tumor thyroid cells. Additionally, potential epigenetic mechanisms involved in these changes will be evaluated, seeking a better understanding of the effects of these EDCs on human health.