Assessment of chemical risk factor for breast cancer based on gene expression profiles.

Breast cancer is one of the leading types of cancer diagnosis worldwide. Although the relationship between hormone exposure and breast cancer has been established, the role of environmental chemicals that induce alterations in mammary gland development and function remains understudied. This highlights the need for additional research into chemicals that may be involved in breast cancer progression. In this study, we analyzed transcriptomics data on MCF7 cell lines exposed to a set of 161 suspected mammalian carcinogens chemicals. From these data, we identified genes and pathways that impact the regulation of cellular proliferation and death processes, as well as cellular repair systems (regulation of the apoptotic process and cellular response to DNA damage stimuli). We also observed significant up-regulation of signaling pathways crucial to cancer development, such as the negative regulation of the MAPK cascade and the regulation of signal transduction by p53 class mediator. Furthermore, through an in vitro/ex vivo comparison, using RNA sequencing from 1,092 breast cancer tissues obtained from the TCGA-BRCA dataset, we identified a set of chemicals that share similar gene deregulation patterns with at least one patient. These compounds should be investigated further as they could be involved in breast cancer progression.