Background and purpose: The previous research has found that the prostate stromal cells derived from different prostate zones have distinct effect on prostate epithelial cells. We also revealed that LMO2 protein was highly expressed in PZ stromal cells (PZSCs) and prostate cancer associated fibroblasts (CAFs) compared with TZ stromal cells. This study investigated the effect of LMO2 protein in prostate stromal cells on proliferation and invasion of prostate cancer PC-3 cells and its mechanisms. Methods: Lentivirus overexpression vectors were used to establish LMO2-overexpressed prostate WPMY-1 stromal cell line. shRNA plasmids were used to suppress LMO2 in CAFs. LMO2 mRNA and protein level of both WPMY-1 and CAFs were evaluated by real-time fluorescent quantitative polymerase chain reaction (RTFQ-PCR) and Western blot. Then

PC-3 cells were co-cultured with different prostate stromal cells and the in vitro proliferation and invasion of PC-3 were measured by CCK-8 and matrigel invasion assays respectively. Results: When co-cultured with LMO2-overexpressed prostate stromal cells

both proliferation and invasion of PC-3 were improved. However

when co-cultured with CAFs which have inhibited expression of LMO2

the proliferation and invasion of PC-3 were reduced. The protein array profiling found that both interleukin-11 (IL-11) and fibroblast growth factor-9 (FGF-9) were enhanced extensively in the supernatant collected from LMO2-overexpressed WPMY-1 cells. Conclusion: The expression of LMO2 in prostate stromal cells could be responsible for development of prostate cancer. Paracrine of cytokines

such as IL-11 and FGF-9

from LMO2-overexpressed stromal cells had effects on the proliferation and invasion of prostate cancer cells.