Liu S.,George Whipple Laboratory for Cancer Research |
Lin S.-J.,George Whipple Laboratory for Cancer Research |
Li G.,Zhejiang University |
Kim E.,Chonnam National University |
And 6 more authors.
Endocrine-Related Cancer | Year: 2014
Peroxisome proliferator-activated receptor γ (PPARγ , NR1C3) and testicular receptor 4 nuclear receptor (TR4, NR2C2) are two members of the nuclear receptor (NR) superfamily that can be activated by several similar ligands/activators including polyunsaturated fatty acid metabolites, such as 13-hydroxyoctadecadienoic acid and 15-hydroxyeicosatetraenoic acid, as well as some anti-diabetic drugs such as thiazolidinediones (TZDs). However, the consequences of the transactivation of these ligands/activators via these two NRs are different, with at least three distinct phenotypes. First, activation of PPARγ increases insulin sensitivity yet activation of TR4 decreases insulin sensitivity. Second, PPARγ attenuates atherosclerosis but TR4 might increase the risk of atherosclerosis. Third, PPARγ suppresses prostate cancer (PCa) development and TR4 suppresses prostate carcinogenesis yet promotes PCa metastasis. Importantly, the deregulation of either PPARγ or TR4 in PCa alone might then alter the other receptor's influences on PCa progression. Knocking out PPARγ altered the ability of TR4 to promote prostate carcinogenesis and knocking down TR4 also resulted in TZD treatment promoting PCa development, indicating that both PPARγ and TR4 might coordinate with each other to regulate PCa initiation, and the loss of either one of them might switch the other one from a tumor suppressor to a tumor promoter. These results indicate that further and detailed studies of both receptors at the same time in the same cells/organs may help us to better dissect their distinct physiological roles and develop better drug(s) with fewer side effects to battle PPARγ - and TR4-related diseases including tumor and cardiovascular diseases as well as metabolic disorders. © 2014 Society for Endocrinology.
Kim S.-J.,Chonnam National University |
Choi H.,Chonnam National University |
Park S.-S.,Chonnam National University |
Chang C.,George Whipple Laboratory for Cancer Research |
And 2 more authors.
Molecules and Cells | Year: 2011
Stearoyl-CoA desaturase (SCD), the rate-limiting enzyme in the biosynthesis of monounsaturated fatty acids, is highly expressed in prostate cancer although the SCD protein has been known to be rapidly turned over by proteolytic cleavage. The present data demonstrate that SCD can promote proliferation of androgen receptor (AR)-positive LNCaP prostate cancer cells and enhance dihydrotestosterone (DHT)-induced AR transcriptional activity, resulting in increased expression of prostate-specific antigen (PSA) and kallikrein-related peptidase 2 (KLK2). Interestingly, among the previously reported SCD-derived peptides produced by proteolytic cleavage of SCD, a peptide spanning amino acids 130-162 of SCD (SCD-CoRNR) contained the CoRNR box motif (LFLII) and enhanced AR transcriptional activity. In contrast, a mutant SCD-CoRNR in which Leu 136 was replaced by Ala had no effect on AR transcriptional activity. Moreover, SCD-CoRNR directly interacted with AR and inhibited RIP140 suppression of AR transactivation. Knockdown of the SCD gene by SCD microRNA suppressed AR transactivation with decreased cell proliferation, suggesting that SCD may regulate the proliferation of LNCaP cells via modulation of AR transcriptional activity. Moreover, ectopic expression of SCD in LNCaP cells facilitated LNCaP tumor formation and growth in nude mice. Together, the data indicate that SCD plays a key role in the regulation of AR transcriptional activity in prostate cancer cells.
Lee S.O.,George Whipple Laboratory for Cancer Research |
Tian J.,George Whipple Laboratory for Cancer Research |
Tian J.,Tianjin Medical University |
Huang C.-K.,George Whipple Laboratory for Cancer Research |
And 8 more authors.
Journal of Endocrinology | Year: 2012
Early studies have reported the differential roles of androgen receptor (AR) in different types (luminal, basal intermediate, and stromal) of prostate cancer cells. In vivo mouse model tumor studies using the total prostate epithelial knockout mice (pes-ARKO) also revealed that AR played a suppressive role in proliferation of the CK5+/CK8+ progenitor/intermediate cells but a positive role in the CK5-/CK8+ luminal epithelial cells. Using three different resources (one human basal epithelial cell line, one mouse basal epithelial originated progenitor cell line, and a basal epithelium-specific ARKO mouse model), we here demonstrated that the AR in basal epithelial cells of normal prostate plays a suppressive role in their proliferation but a positive role in differentiation into luminal epithelial cells. These results led us to conclude that ARs may play a negative role to suppress CK5+ basal epithelial and progenitor cell proliferation, yet play an essential role to drive basal epithelial cells into more differentiated states. These results may explain why differential AR expression in different cell types within normal prostate is needed and suggest that ARs in prostate basal epithelial cells, although expressed at a very low level, are necessary to maintain the balance between progenitor cells and differentiated luminal epithelial cells. © 2012 Society for Endocrinology.
Ding X.,Zhejiang University |
Ding X.,George Whipple Laboratory for Cancer Research |
Yang D.-R.,George Whipple Laboratory for Cancer Research |
Yang D.-R.,Soochow University of China |
And 8 more authors.
Molecular Cancer | Year: 2015
Background: TR4 nuclear receptor 4 (TR4) plays an important role in macrophages-associated foam cell formation of cardiovascular diseases and infiltrating macrophages are critical for prostate cancer (PCa) progression. However, the linkage of macrophages and TR4 and their impacts on PCa metastasis remains unclear. Results: Knocking-down TR4 in human PCa cells (C4-2, CWR22Rv1), but not in human macrophages cells (THP-1), led to suppress the macrophages infiltration to PCa cells. The consequences of such suppression of the recruitment of macrophages toward PCa then resulted in suppressing the PCa cell invasion. Mechanism dissection found that knocking-down TR4 in PCa cells suppressed metastasis-related genes including MMP2, with induction of TIMP-1. Interruption assays using TIMP-1 neutralizing antibody could then reverse TR4-macrophage-mediated PCa invasion. IHC staining showed higher TR4 level, more macrophage infiltration, lower TIMP-1 and stronger MMP2/MMP9 in tumor tissues of the Gleason score 5 + 4 patients compared with the Gleason score 3 + 3 patients. Conclusion: Targeting TR4 in prostate tumor microenvironment might represent a potential new therapeutic approach to better battle PCa metastasis. © Ding et al.