Figure 2. SM-DR and CAM-DR contribute to drug resistance.
BMSCs are the major source of IL-6. IL-6 up-regulates the Mcl-1 and Bcl-XL through JAK/STAT3, PI3K/Akt and MEK/MAPK that are known to augment survival and drug resistance. CAM-DR induces a multidrug resistant phenotype as cell adhesion can protect tumors cells from chemotoxic agents in MM. CAM-DR can also cause to express of soluble factor in conferring tumor cell drug resistance.