Revamping Anticancer Strategies by Modulating Tumor Microenvironment Using Botanicals

The successful development and progression of cancer is dependent not only upon the growth and proliferation of transformed cells but relies equally upon the formation of a conducive tumor microenvironment (TME). Several kinds of immune cells, nonimmune cells, cancer stem cells, and microbes comprise the cellular component of TME. The noncellular component comprises mostly of proteins, proteoglycans, metabolites, and various secreted factors. The evolvement of the TME occurs concurrently with the tumor cells gaining metastatic capabilities. The interaction between the growing tumor and the microenvironment is bidirectional and is mediated through cytokines which are secreted both by the tumor cells and the cells of the surrounding stroma. TME has the ability to modulate proliferation, cell death, inflammation, angiogenesis, invasive and metastatic capabilities, and resistance to therapeutics. These effects have significant influence on disease prevention, prognosis, and treatment. Realigning cancer management strategies by targeting the TME along with cancer cells seems like a fitter approach that could possibly yield better outcomes than strategies focused at managing the cancer cells only. This chapter includes information on the components of TME, their interaction with the cancer cells, and effects of TME on various processes crucial to cancer development. On this basis, we have also included information illustrating the TME modulatory potential of plants that exhibit anticancer activities.