BACKGROUND: Tissue inhibitor of metalloproteinase-1 (TIMP-1) is a 28.5 kDa secreted glycoprotein that inhibits matrix metalloproteinase (MMP) activity. Our group has previously shown that elevated plasma TIMP-1 levels predict poor survival in metastatic castration-resistant prostate cancer (CRPC) patients; however, the underlying source and impact of elevated circulating TIMP-1 protein is unknown. METHODS: In this study, we used qRT-PCR, ELISA and immunohistochemistry to evaluate TIMP-1 expression in androgen-sensitive and resistant prostate cancer (PC) cell lines, tumor tissues and patient sera, and to correlate TIMP-1 levels to expression of chromogranin A (CGA), an established marker of neuroendocrine differentiation (NED). We also explored the relationship between TIMP-1 overexpression and induction of NED by overexpressing TIMP-1 in androgen-sensitive LNCaP cells, as well as by inducing NED of LNCaP cells with IL-6. RESULTS: Patients with CRPC have significantly higher serum TIMP-1 levels compared to patients with hormone-sensitive disease. Although circulating TIMP-1 levels were increased, peripheral blood cells were not the source of elevation. Instead, elevated TIMP-1 expression was associated with higher expression of CGA in both blood and metastatic tumor tissue. We further show that androgen receptor (AR) and PSA non-expressing prostate cancer cell lines known to display NED phenotypes such as PC-3, PC-3M, and DU145 cells, expressed high levels of TIMP-1, in contrast to AR (+) and PSA (+) adenocarcinoma cell lines such as LNCaP, VCaP, and LAPC-4, which had barely detectable levels of TIMP-1. In addition, ectopic overexpression of TIMP-1 in LNCaP cells did not induce NED. However, TIMP-1 mRNA expression was elevated >10-fold during IL-6-induced NED of LNCaP cells, suggesting that TIMP-1 overexpression accompanies, but is not the driving force for NED. Finally, we show that conditioned media from androgen-resistant PC-3, PC-3M, and DU145 cells induced TIMP-1 mRNA expression in primary prostate stromal fibroblasts in an ERK and NF-κB dependent manner. CONCLUSIONS: We provide in vitro and clinical evidence to support the association between NED and elevated circulating TIMP-1 expression in CRPC. Our observation supports further evaluation of TIMP-1 as a tissue and serum biomarker for NED in CRPC.
BACKGROUND:Tissue inhibitor of metalloproteinase-1 (TIMP-1) is a 28.5 kDa secreted glycoprotein that inhibits matrix metalloproteinase (MMP) activity. Our group has previously shown that elevated plasma TIMP-1 levels predict poor survival in metastatic castration-resistant prostate cancer (CRPC) patients; however, the underlying source and impact of elevated circulating TIMP-1 protein is unknown. METHODS: In this study, we used qRT-PCR, ELISA and immunohistochemistry to evaluate TIMP-1 expression in androgen-sensitive and resistant prostate cancer (PC) cell lines, tumor tissues and patient sera, and to correlate TIMP-1 levels to expression of chromogranin A (CGA), an established marker of neuroendocrine differentiation (NED). We also explored the relationship between TIMP-1 overexpression and induction of NED by overexpressing TIMP-1 in androgen-sensitive LNCaP cells, as well as by inducing NED of LNCaP cells with IL-6. RESULTS:Patients with CRPC have significantly higher serum TIMP-1 levels compared to patients with hormone-sensitive disease. Although circulating TIMP-1 levels were increased, peripheral blood cells were not the source of elevation. Instead, elevated TIMP-1 expression was associated with higher expression of CGA in both blood and metastatic tumor tissue. We further show that androgen receptor (AR) and PSA non-expressing prostate cancer cell lines known to display NED phenotypes such as PC-3, PC-3M, and DU145 cells, expressed high levels of TIMP-1, in contrast to AR (+) and PSA (+) adenocarcinoma cell lines such as LNCaP, VCaP, and LAPC-4, which had barely detectable levels of TIMP-1. In addition, ectopic overexpression of TIMP-1 in LNCaP cells did not induce NED. However, TIMP-1 mRNA expression was elevated >10-fold during IL-6-induced NED of LNCaP cells, suggesting that TIMP-1 overexpression accompanies, but is not the driving force for NED. Finally, we show that conditioned media from androgen-resistant PC-3, PC-3M, and DU145 cells induced TIMP-1 mRNA expression in primary prostate stromal fibroblasts in an ERK and NF-κB dependent manner. CONCLUSIONS: We provide in vitro and clinical evidence to support the association between NED and elevated circulating TIMP-1 expression in CRPC. Our observation supports further evaluation of TIMP-1 as a tissue and serum biomarker for NED in CRPC.
Authors: Mark A White; Chenchu Lin; Kimal Rajapakshe; Jianrong Dong; Yan Shi; Efrosini Tsouko; Ratna Mukhopadhyay; Diana Jasso; Wajahat Dawood; Cristian Coarfa; Daniel E Frigo Journal: Mol Cancer Res Date: 2017-05-15 Impact factor: 5.852
Authors: Elizabeth V Nguyen; Margaret M Centenera; Max Moldovan; Rajdeep Das; Swati Irani; Andrew D Vincent; Howard Chan; Lisa G Horvath; David J Lynn; Roger J Daly; Lisa M Butler Journal: Mol Cell Proteomics Date: 2018-04-09 Impact factor: 5.911
Authors: Ricardo G Alvim; Christopher Hughes; Alexander Somma; Karan K Nagar; Nathan C Wong; Stephen La Rosa; Sebastien Monette; Kwanghee Kim; Jonathan A Coleman Journal: Ther Adv Urol Date: 2019-03-29