Organochlorine pesticide concentrations in serum from patients with thyroid diseases and effects of endosulfan I and o,p’-DDT on lymph node metastases of thyroid cancer

Organochlorine pesticides (OCPs) are common environmental pollutants. OCPs are detected in human tissues. Many studies have found that OCPs are associated with thyroid diseases, but the specific effects of OCPs on thyroid disease are not clear. We measured and analyzed the concentration of OCPs in the serum of individuals with thyroid disorders. The main components of OCPs in the serum of individuals with thyroid disorders were p,p’-DDE, β-hexachlorocyclohexane (HCH), and hexachlorobenzene (HCB). However, the concentration levels of endosulfan I and o,p’-dichlorodiphenyltrichloroethane (DDT) showed a tendency to be higher in young adults. In addition, the appearance of thyroid cancer lymph node metastasis also showed a trend of younger age. The serum concentrations of endosulfan I and o,p’-DDT were higher in patients without signs of lymph node metastasis cancer than in individuals diagnosed with thyroid cancer without cancer spread to the lymph nodes. The scratch healing assay showed that endosulfan I and o,p’-DDT-treated experimental group had faster scratch wound healing, which indicated that endosulfan I and o,p’-DDT could promote the enhancement of the migration ability of the thyroid cancer cells, and similar results were obtained by the Transwell migration assay. This study suggests that endosulfan I and o,p’-DDT can promote lymph node metastasis of thyroid cancer.