We’ve all heard the slogans about how to lessen our impact on the environment: Reduce, Reuse, Recycle. But, what about the impact of microenvironments on us? Scientists have known for years that tumor growth is supported by the surrounding microenvironment, and now a group of Italian researchers have identified miRNAs as the masters that control the prostate tumor microenvironment.
The Italian group’s previous work identified miR-15a and miR-16-1 (miR-15/16) as being downregulated in human prostate tumors and when they dug into things a little deeper in the stroma they found that:
- mir-15/16 were downregulated in stromal cells surrounding prostate tumors and in cultured cancer-associated fibroblasts (CAFs) but not in stromal cells surrounding normal prostate tissue or in cultured non-neoplastic associated fibroblasts (NAFs).
- Re-expression of mir-15/16 in CAFs resulted in reduced tumor cell motility and proliferation in vitro and reduced stromal cell support of tumor expansion in vivo.
- New targets for mir-15/16 were identified as FGF2 (fibroblast growth factor 2) and FGFR1 (fibroblast growth factor receptor 1), which are involved in prostate stromal/epithelial communication.
Since mir-15/16 and FGF signaling have been implicated in various types of tumors, these two microRNAs present a potential therapy that can be reused to inhibit FGF signaling and target both the tumor and its microenvironment.
For more hints on the microenvironmental impact of microRNAs, see Oncogene May 2011.