Targeting tumor microenvironment-associated cells to reverse therapy resistance

About 30%–70% of the cells in any tumor are composed of noncancerous cells [1], [2], with the most abundant cells in GBM coming from bone marrow-derived cells [3], [4]. Although the presence of cancer-associated fibroblasts in the GBM environment is controversial, there are plentiful microglia [5], [6], [7], [8]. Microglia are known to contribute to the immunosuppressive environment of gliomas. In this chapter, the influence of different GBM TME-associated cells (such as bone marrow derived cells) will be discussed concerning the possible cause of therapy resistance. The discussion will also involve possible ways to prevent therapy resistance due to TME-associated cells.