Issues

Oxidative stress accelerates the pathogenesis of a number of chronic diseases, including cancer growth and its metastasis. Transcription factorNrf2 (NF-E2–related factor-2) regulates the cellular defense system against oxidative stress. Systemic deletion of Nrf2 brings about an increased susceptibility to cancer metastasis, which is associated with aberrant ROS (reactive oxygen species) accumulation inmyeloid-derived suppressor cells (MDSCs). However, it remains elusive whether cellular antioxidant defense system regulated by Nrf2 signaling in the myeloid lineage cells plays indispensable roles for metastatic cancer progression. In this study, myeloid lineage–specific Nrf2-deficient (N-MKO) mice are inoculated with mouse Lewis lung carcinoma cells and metastatic activity of the cells is examined. The cover micrograph depicts metastatic cancerous lesions in the lung tissue of tumor-bearing N-MKO mouse. Note that N-MKO mice develop multiple metastatic lung nodules, indicating that the Nrf2-deficiency in myeloid lineage cells accelerates cancer cell metastasis. See the article by Hiramoto and colleagues (beginning on page 835) for more information.