The role of melatonin hormone and its receptor (type1A) as anti-cancer against carcinogenic effect of polyaromatic hydrocarbons in Iraqi refinery workers

Abstract

Air pollution is a global health threat and causes millions of human deaths annually. Outdoor and indoor air pollutants such as polycyclic aromatic hydrocarbons (PAHs) are the most prevalent cause of respiratory disorders, lung disease, pregnancy disorders, endocrine disturbances, diabetes, obesity, cardiovascular disease and cancer because pollutants can alter gene expression via epigenetics like DNA methylation and histone modifications which can initiate tumorigenesis and progressed to cancer. Carcinogenicity of PAHs can be eliminated by endogenous melatonin hormone (MT) via binding to its receptor (MTNR1A) that act as free radicals scavenger therefore it protects the body from developing occupational cancer. Aims of studyTo predict the protective effect of melatonin hormone as anti-cancer through binding to its receptor (MTNR1A) against any type of cancer that can be induced by chronic exposure to air pollutants. Subjects and methodsThis study includes 168 participants, they have been divided into three groups (control, refinery field workers and refinery office workers). PAH was analyzed for each participant by GC/MS whereas melatonin hormone and MTNR1A were measured by ELISA technique. ResultsPAHs were absent in the blood of control, and they were elevated in refinery worker’s specimens. Concentration of MT was higher in field worker than in office and control group as well as MTNR1A, also there is a relation between their levels and duration of exposure. ConclusionExposure to PAHs can lead to oxidative stress that can damage DNA resulting in many types of cancer but this carcinogenic effects of PAHs can be eliminated by natural endogenous biomolecules such as MT and its receptor (MTNR1A) therefore their elevation has a beneficial effect as anti-cancer to reduce the oxidative stress and prevent tumorigenesis.