Environmental plastic pollutants and endocrine-related cancer: An updated view

Micro- and nano-plastics (MNPs) are debris generated from the fragmentation of larger plastic particles. Due to their pervasive and persistent nature, MNPs - accumulated in the environment and widespread distributed across diverse ecosystems - have been detected in human blood, tissues and cells. Once considered as biologically inert, MNPs are emerging as cellular stressors with acknowledged biological properties, leading to diverse physio-pathological responses. Herein, we present the most recent findings regarding the actions of MNPs as endocrine disruptors, emphasizing the novel findings suggestive of a potential stimulatory role played by these environmental pollutants in hormone-related cancers. In this vein, we provide a critical overview of the molecular mechanisms and the metabolic pathways activated by MNPs and implicated in the disruption of hormone/hormone receptor signaling, possibly leading to cancer progression. Next, we highlight the main areas of knowledge gap in the field, suggesting novel approaches that may allow a better understanding of environmental MNPs' action in human diseases. Considering the escalating environmental exposure to MNPs envisaged for the next years, irrespective of any counteractive measure, our comprehensive and detailed analysis contributes to a better evaluation of the endocrine effects associated with these emergent environmental pollutants. Our work corroborates research efforts worldwide, helping to build and expand knowledge on the endocrine effects elicited by MNPs, also in hormone-related cancers.