Chemokine CXCL3 mediates prostate cancer cells proliferation, migration and gene expression changes in an autocrine/paracrine fashion.

INTRODUCTION: We have previously indicated that CXCL3 was upregulated in the tissues of prostate cancer, and exogenous administration of CXCL3 played a predominant role in the tumorigenicity of prostate cancer cells. In the present study, we further explored the role and the underlying mechanism of CXCL3 overexpression in the oncogenic potential of prostate cancer in an autocrine/paracrine fashion. METHODS: CXCL3-overexpressing prostate cancer cell line PC-3 and immortalized prostate stromal cell line WPMY-1 were established by gene transfection. CCK-8, transwell assays and growth of tumor xenografts were conducted to characterize the effects of CXCL3 on PC-3 cells' proliferation and migration. Western blotting was conducted to test whether CXCL3 could affect the expression of tumorigenesis-associated genes. RESULTS: The results showed that CXCL3 overexpression in PC-3 cells and the PC-3 cells treated with the supernatants of CXCL3-transfected WPMY-1 cells stimulated the proliferation and migration of PC-3 cells in vitro and in a nude mouse xenograft model. Western blotting revealed higher levels of p-ERK, Akt and Bcl-2 and lower levels of Bax in the tumor xenografts transplanted with CXCL3-transfected PC-3 cells. Moreover, the tumor xenografts derived from the PC-3 cells treated with supernatants of CXCL3-transfected WPMY-1 cells showed higher expression of ERK, Akt and Bcl-2 and lower expression of Bax. CONCLUSIONS: These findings suggest that CXCL3 autocrine/paracrine pathways are involved in the development of prostate cancer by regulating the expression of the target genes that are related to the progression of malignancies.

[Protective effects of adiponectin on myocardial ischemia-reperfusion injury in rats].

OBJECTIVE: To investigate the protective effects of adiponectin on myocardial ischemia-reperfusion injury and the potential mechanisms in rats. METHODS: Thirty-two male rats aged 8 weeks were randomly assigned to sham operation (sham), myocardial ischemia-reperfusion (MIR), diltiazem treatment (diltiazem) or adiponectin administration (APN) groups (n = 8 each). MIR rats underwent left anterior descending artery (LAD) occlusion for 30 min followed by 60 min reperfusion. Diltiazem (7 microg/g) and APN (120 ng/g) were given by caudal intravenous injection at the end of 30 min ischemia and the beginning of reperfusion for rats in diltiazem or APN groups. Animals were sacrificed after 60 min reperfusion for determining the myocardial nitric oxide (NO), Caspase 3, activity of AMP-activated protein kinase(AMPK) and concentration of peroxisome proliferators-activated receptor gamma (PPARgamma). Apoptotic cells were stained by Caspase 3 Activity Assay Kit and mitochondria in myocardial cells were observed by transmission electron microscope (TEM). RESULTS: The myocardial Caspase 3 level was significantly increased [(168.50 +/- 30.08) micromol/L vs. (53.25 +/- 11.41) micromol/L, P < 0.01], AMPK activity, PPARgamma and NO concentrations were significantly reduced in MIR group compared with those in sham group (all P < 0.05) [(0.74 +/- 0.59) IU/ml vs. (25.63 +/- 4.61) IU/ml, P < 0.01; 0.1894 vs. 0.7949, P < 0.01; (6.359 +/- 1.355) micromol/L vs. (10.396 +/- 1.901) micromol/L, P < 0.01], these effects could be significantly reversed by APN. In comparison with MIR group, the levels of Caspase 3 in cardiac muscles were significantly lowered in Adiponectin group [(88.75 +/- 6.92) micromol/L vs. (168.50 +/- 30.08) micromol/L, P < 0.01], whereas the level of AMPK and PPARgamma, NO concentration in the cardiac muscle was remarkably increased [(27.22 +/- 4.76) IU/ml vs. (0.74 +/- 0.59) IU/ml, P < 0.01; 0.8613 vs. 0.1894, P < 0.01; (15.755 +/- 1.045) micromol/L vs. (6.359 +/- 1.355) micromol/L, P < 0.01]. APN also preserved the function and structure of mitochondria in rats post ischemia/reperfusion injury. The protective pharmacologic actions of APN were superior to that of diltiazem. CONCLUSION: Adiponectin could protect myocardial tissues from myocardial ischemia-reperfusion injury in rats, possibly by upregulating myocardial AMPK and PPARgamma expressions and preventing myocardial cells from apoptosis.