Overview of Cadmium Thyroid Disrupting Effects and Mechanisms

Abstract

Humans are exposed to a significant number of chemicals that are suspected to produce disturbances in hormone homeostasis. Hence, in recent decades, there has been a growing interest in endocrine disruptive chemicals. One of the alleged thyroid disrupting substances is cadmium (Cd), a ubiquitous toxic metal shown to act as a thyroid disruptor and carcinogen in both animals and humans. Multiple PubMed searches with core keywords were performed to identify and evaluate appropriate studies which revealed literature suggesting evidence for the link between exposure to Cd and histological and metabolic changes in the thyroid gland. Furthermore, Cd influence on thyroid homeostasis at the peripheral level has also been hypothesized. Both in vivo and in vitro studies revealed that a Cd exposure at environmentally relevant concentrations results in biphasic Cd dose-thyroid response relationships. Development of thyroid tumors following exposure to Cd has been studied mainly using in vitro methodologies. In the thyroid, Cd has been shown to activate or stimulate the activity of various factors, leading to increased cell proliferation and a reduction in normal apoptotic activity. Evidence establishing the association between Cd and thyroid disruption remains ambiguous, with further studies needed to elucidate the issue and improve our understanding of Cd-mediated effects on the thyroid gland.

Blood screening for heavy metals and organic pollutants in cancer patients exposed to toxic waste in southern Italy: A pilot study

“…Although several studies focused on the ability of heavy metals and POPs to alter the functionality of the endocrine system (Beszterda & Franski, 2018;Buha et al, 2018;Kranthi Kumar, Uma Devi, & Neeraja, 2018;Paschoalini, Savassi, Arantes, Rizzo, & Bazzoli, 2019;Saxena, Purchase, Mulla, Saratale, & Bharagava, 2020), their involvement in cancer development is also increasingly emerging (Cao, Fan, Li, & Xiao, 2019;Leng et al, 2016;Rehman, Fatima, Waheed, & Akash, 2018).…”

Toxic Effects of the Mixture of Phthalates and Bisphenol A—Subacute Oral Toxicity Study in Wistar Rats

“…Some of the already identified and well-established chemicals with endocrine-disrupting properties include organochlorine pesticides, polybrominated diphenyl ethers, polychlorinated biphenyls, toxic metals, as well as phthalates and bisphenol A [1,[20][21][22][23]. The results from a recent nation-wide survey of the levels of environmental contaminants among pregnant women in France showed that these chemicals are quantifiable in virtually all individuals [24].…”

Toxic-Metal-Induced Alteration in miRNA Expression Profile as a Proposed Mechanism for Disease Development

“…Our understanding of the importance of miRNAs in cancer development has increased over the last few decades. The International Agency for Cancer Research (IARC) has classified Cd as a human carcinogen with a well-established association to kidney and prostatic cancers [62] as well as considerable involvement in other cancers, such as pancreatic cancer [63][64][65] and thyroid cancer [66], among which the role of miRNA in Cd-induced carcinogenesis is of great value. Evidence supporting the toxic metal modification of miRNA expression and cancer development is increasing, with Cd and As being two primary mediators [60,67].…”