ABSTRACT
Persistent Organic Pollutants (POPs) have the characteristics of resistance to environmental degradation, bioaccumulation and long-distance migration potential. Maternal exposure to POPs during pregnancy can enter the fetal blood circulation through the placental barrier, and have a potential impact on the functional development of the nervous system of the offspring. This in turn leads to the occurrence and development of neurological defects and diseases in adulthood. The purpose of this paper is to elucidate the effects of exposure to three major POPs (organochlorine compounds, perfluoroalkyl and polyfluoroalkyl substances, and polybrominated diphenyl ethers) during pregnancy on the functional development of the nervous system (social emotions, cognition, language, exercise, and adaptability) in children, and to provide reference for subsequent studies.
Subject(s)
Nervous System , Persistent Organic Pollutants , Prenatal Exposure Delayed Effects , Pregnancy , Humans , Female , Child , Nervous System/drug effects , Nervous System/growth & development , Maternal Exposure/adverse effects , Halogenated Diphenyl Ethers/toxicity , Hydrocarbons, Chlorinated , Child Development/drug effects , Environmental Pollutants/toxicityABSTRACT
BACKGROUND: High tumor mutational burden (TMB) is one of the widely researched predictive biomarkers of immune checkpoint inhibitors and has been shown to be closely related with response to immunotherapy in multiple cancer types. However, for patients who have failed conventional therapy and are about to undergo immunotherapy, there is no consensus recommendation on the timing of tumor sampling for TMB analysis, and the effects of different therapies on TMB have not been clarified. This retrospective observational study aimed to investigate the heterogeneity of TMB and genomic mutation under the treatment pressure. PATIENTS AND METHODS: We retrospectively collected the available genomic and therapeutic information from 8051 samples across 15 tumor types (>50 samples/tumor) found in 30 published studies and investigated the distribution and heterogeneity of TMB under treatment across diverse cohorts. RESULTS: This integrated analysis has shown anticancer treatments increased TMB. Significant effects of treatment on TMB were more frequently observed in tumor types with lower treatment-naïve TMB, including breast, prostate, and pediatric cancers. For different cancer therapies, chemotherapy was prone to be correlated with an increased TMB in most cancer types. Meanwhile, the fraction of the TMB-high category of breast, prostate, and bladder cancers and glioma increased significantly after chemotherapy. Several actionable genes including ERS1 and NF1 in breast cancer, as well as some prognostic markers including TERT in bladder cancer and IDH1 in glioma, were significantly changed in post-chemotherapy tumors compared to treatment-naïve tumors. CONCLUSION: Our study reveals the heterogeneity of TMB under treatment across diverse cancer types and provides evidences that chemotherapy was associated with increases in TMB as well as the fraction of TMB-high category, suggesting that resampling tumor tissues for calculating post-chemotherapy TMB could be a better option for predicting the response to immunotherapy, especially for tumors with initially low TMB.