Search

Objective To study expression of NDRG3 in prostatic mesenchyma and effect of exogenous NDRG3 on prostatic stromal cells. Methods Immunohistochemical analysis was used to check expression of NDRG3 in prostate mesnenchyma. The WPMY-1 prostate immortalized mesenchyma cell line was stably-transfected with a NDRG3 gene expression vector. The NDRG3-stable transfected WPMY-1 sublines were studied along with parental and empty vector transfected WPMY-1 cells as controls. RT-PCR technology was applied to identity downstream gene expression under regulation of NDRG3 expression. Results Expression of DNRG3 was observed in prostate cancer mesenchyma, over-expression of NDRG3 in WPMY-1 cell up-regulated expression of chemotatic factors-CXCL3 and CXCL5. Conclusion Expression of stromal NDRG3 in prostate cancer specimens is significantly higher than that in benign prostatic hypertrophy (BPH) sample. There is a remarkable difference between the two groups of samples, NDRG3 may be related to angiogenesis in prostatic mesenchyma.

A human high mobility group box 4 (hHMGB4) expression construct (pET‑28a/hHMGB4) was generated by cloning the hHMGB4 full‑length cDNA in the expression vector pET‑28a(+). The hHMGB4 fusion protein with His6‑Tag was prepared using E.coli BL21 (DE3) transformed with pET‑28a/hHMGB4 and purified via preparative SDS‑PAGE plus electroelution. Immunization of rabbits with the purified hHMGB4 generated polyclonal antibodies. The titer of the antiserum was determined to be 1:102,400 by ELISA analysis. Western blotting analysis showed that the antibody specifically recognized the recombinant hHMGB4 protein and also the endogenous hHMGB4 protein in prostate cancer cells. In addition, immunohistochemical staining analysis using the prepared antibody revealed marked hHMGB4 staining in the nuclei of the human prostate tissue. These data demonstrate that the anti‑hHMGB4 polyclonal antibody may be a useful reagent for the functional study of hHMGB4.

NDRG3 belongs to the N-myc down-regulated gene (NDRG) family that contains 4 paralogs: NDRG1, -2, -3 and -4. The function of NDRG3 and its relationship to cancer has not been studied. We herein report our examination of the expression and biological roles of NDRG3 in prostate cancers. We showed that NDRG3 expression is enriched in testis and prostate using gene expression data derived from massively parallel signature sequencing from 33 different human organs. We further showed that NDRG3 is expressed in both epithelial prostate cancer cells and prostatic stromal cells at both mRNA and proteins levels. We demonstrated that NDRG1 is significantly up-regulated by androgen in LNCaP cells. Over-expression of NDRG3 in stably transfected PC-3 cells increased their growth rates and migration capabilities when compared to parental or mock empty vector transfected PC-3 cells. In addition, we found that overexpresson of NDRG3 promoted the growth of xenograft tumors in nude mice. Finally, we found that NDRG3 expression was detected in 58.6% (41/70) of prostate cancer specimens compared to 13.2% (5/38) of benign prostatic hyperplasia specimens by immunohistochemistry. We showed by microarray and by RT-PCR that NDRG3 overexpression up-regulates the expression of many angiogenic chemokines including CXCL1 (chemokine ligand 1), CXCL3 (chemokine ligand 3) and CXCL5 (chemokine ligand 5), which may increase angiogenesis of tumors. Taken together, these results demonstrate that NDRG3 is a tumor promoter, the overexpression of which may contribute to the malignant phenotype of tumors.