Targeting emerging cancer hallmarks by transition metal complexes: Cancer stem cells and tumor microbiome. Part I

In this last decade, our understanding of the complex factors and processes that drive cancer development and progression has broadened in scope and grown in depth. Today, it is widely held that as a dis-ease, cancer can be characterized in terms of specific hallmarks that normal cells need to acquire to transform into malignant cells. Because it is both logical and intuitive, the hallmarks of cancer concept have been adopted by both the scientific and medical community as an organising principle to under-stand cancer and to develop new therapeutic approaches. Several new hallmarks have emerged in recent years arising from a better understanding of the crosstalk between cancer cells and their surrounding tumor microenvironment. There is evidence of the so-called "metallic" crosstalk that is linked to neoplastic cell transformation. The current review is based on the collaborative efforts of bioinorganic chemists, molecular biologists and medical doctors. It summarizes the therapeutic strategies developed for targeting phenotypic plasticity and cancer microbiome arising from interactions with transition metals and dis-cusses whether transition metal complexes might offer therapeutic advantages compared to current treatment options. © 2022 Elsevier B.V. All rights reserved.