Project description:Dynamic interaction between prostate cancer and the bone microenvironment is a major contributor to metastasis of prostate cancer to bone. In this study we utilized an in-vitro co-culture model of PC3 prostate cancer cells and osteoblasts followed by microarray based gene expression profiling to identify previously unrecognized prostate cancer-bone microenvironment interactions. Factors secreted by PC3 cells resulted in the up-regulation of many genes in osteoblasts associated with bone metabolism and cancer metastasis, including Mmp13, Il-6 and Tgfb2, and down-regulation of Wnt inhibitor Sost. To determine whether altered Sost expression in the bone microenvironment has an effect on prostate cancer metastasis, we co-cultured PC3 cells with Sost knockout (SostKO) osteoblasts and wildtype (WT) osteoblasts and identified several genes differentially regulated between PC3-SostKO osteoblast co-cultures and PC3-WT osteoblast co-cultures. Co-culturing PC3 cells with WT osteoblasts up-regulated cancer-associated long noncoding RNA (lncRNA) MALAT1 in PC3 cells. MALAT1 expression was further enhanced when PC3 cells were co-cultured with SostKO osteoblasts and treatment with recombinant Sost down-regulated MALAT1 expression in these cells. Our results suggest that reduced Sost expression in the tumor microenvironment may promote bone metastasis by up-regulating MALAT1 in prostate cancer.
Project description:Disseminated prostate cancer cells colonize the skeleton to progress into macroscopic lesions only if they successfully adapt to the bone microenvironment. We previously reported that the ability of prostate cancer cells to generate skeletal tumors in animal models correlated with the expression of the alpha-receptor for Platelet-Derived Growth Factor (PDGFRa). In this study we aimed to identify PDGFRa-regulated genes responsible for the acquisition of a bone-metastatic prostate phenotype. We performed genome-wide expression comparative analyses of human prostate cancer cell lines that differ for PDGFRa expression and propensity to establish tumors in the skeleton of animal models. We investigated the genes that were differentially regulated in the highly bone-metastatic PC3-ML cells and their low-metastatic counterpart PC3-N cells, and the genes differentially regulated between PC3-N and PC3-N with overexpression of PDGFRa (PC3NRa). We have previously shown that DU-145 cells lack PDGFRa and fail to survive longer than three days as disseminated tumor cells after homing to the mouse bone marrow. Interestingly, and in contrast to PC3-N cells, the exogenous expression of PDGFRa did not promote metastatic bone-tropism of DU-145 cells in our model. Thus, we examined the genes that were differentially regulated between DU-145 and DU-145(Ra) and excluded them from our candidate genes. Finally, to refine our findings and compensate for PC3 and DU-145 genetic disparity, we performed a comparative analysis of the genes differentially regulated between two bone metastatic single-cell progenies that were derived from PC3-ML cells.
Project description:Disseminated prostate cancer cells colonize the skeleton to progress into macroscopic lesions only if they successfully adapt to the bone microenvironment. We previously reported that the ability of prostate cancer cells to generate skeletal tumors in animal models correlated with the expression of the alpha-receptor for Platelet-Derived Growth Factor (PDGFRa). In this study we aimed to identify PDGFRa-regulated genes responsible for the acquisition of a bone-metastatic prostate phenotype. We performed genome-wide expression comparative analyses of human prostate cancer cell lines that differ for PDGFRa expression and propensity to establish tumors in the skeleton of animal models. We investigated the genes that were differentially regulated in the highly bone-metastatic PC3-ML cells and their low-metastatic counterpart PC3-N cells, and the genes differentially regulated between PC3-N and PC3-N with overexpression of PDGFRa (PC3NRa). We have previously shown that DU-145 cells lack PDGFRa and fail to survive longer than three days as disseminated tumor cells after homing to the mouse bone marrow. Interestingly, and in contrast to PC3-N cells, the exogenous expression of PDGFRa did not promote metastatic bone-tropism of DU-145 cells in our model. Thus, we examined the genes that were differentially regulated between DU-145 and DU-145(Ra) and excluded them from our candidate genes. Finally, to refine our findings and compensate for PC3 and DU-145 genetic disparity, we performed a comparative analysis of the genes differentially regulated between two bone metastatic single-cell progenies that were derived from PC3-ML cells. Seven human prostate cancer cell lines were analyzed in total for this study. Each cell line was analyzed in duplicate from two different passages in culture.
Project description:The epidemiologic association between statin use and decreased risk of advanced prostate cancer suggests that statins may inhibit prostate cancer development and/or progression. Studies were performed to determine the effects of a model statin, atorvastatin (ATO), on the proliferation and differentiation of prostate cancer cells, and to identify possible mechanisms of ATO action. ATO inhibited the in vitro proliferation of both LNCaP and PC3 human prostate cancer cells in dose-dependent fashion. The greater inhibitory activity of ATO in PC3 cells was associated with induction of autophagy in that cell line, as demonstrated by increased expression of LC3-II. miR-182 was consistently upregulated by ATO in PC3 cells, but not in LNCaP cells. ATO upregulation of miR-182 in PC3 cells was p53-independent and was reversed by geranylgeraniol. Transfection of miR-182 inhibitors decreased expression of miR-182 by >98% and attenuated the antiproliferative activity of ATO. miR-182 expression in PC3 cells was also increased in response to stress induced by serum withdrawal, suggesting that miR-182 upregulation can occur due to nutritional stress. Bcl2 and p21 were identified to be potential target genes of miR-182 in PC3 cells. Bcl2 was downregulated and p21 was upregulated in PC3 cells exposed to ATO. These data suggest that miR-182 may be a stress-responsive miRNA that mediates ATO action in prostate cancer cells.