scholarly journals Expression of GnRH type II is regulated by the androgen receptor in prostate cancer

2007 ◽  
Vol 14 (3) ◽  
pp. 613-624 ◽  
Author(s):  
S Darby ◽  
J Stockley ◽  
M M Khan ◽  
C N Robson ◽  
H Y Leung ◽  
...  

GnRH II has important functional effects in steroid hormone-dependent tumours. Here we investigated the expression and regulation of GnRH II in prostate cancer. GnRH II protein was equally expressed in benign (73%) and malignant (78%) biopsies studied in a prostate tissue microarray (P = 0.779). There was no relationship between expression and clinical parameters in the cancer cohort. GnRH II was, however, significantly reduced in tumour biopsies following hormone ablation. This was further investigated in a prostate xenograft model where androgens increased GnRH II levels, while their withdrawal reduced it. In cell lines, we confirmed high levels of GnRH II in androgen receptor (AR)-positive LNCaP cells but low levels in AR-negative PC3 cells. In LNCaP cells, GnRH II induction by androgens was blocked by the AR inhibitor casodex, but not by cycloheximide treatment. Sequence analysis subsequently revealed a putative androgen response element in the upstream region of the GnRH II gene and direct interaction with the AR was confirmed in chromatin immunoprecipitation experiments. Finally, to test whether the effects of GnRH II were dependent on AR expression, LNCaP and PC3 cells were exposed to exogenous peptide. In both cell lines, GnRH II inhibited cell proliferation and migration, suggesting that its function is independent of AR status. These results provide evidence that GnRH II is widely expressed in prostate cancer and is an AR-regulated gene. Further studies are warranted to characterise the effects of GnRH II on prostate cancer cells and investigate its potential value as a novel therapy.

Cancers ◽  
2022 ◽  
Vol 14 (2) ◽  
pp. 409
Author(s):  
Alicja Chrzanowska ◽  
Wioletta Olejarz ◽  
Grażyna Kubiak-Tomaszewska ◽  
Andrzej K. Ciechanowicz ◽  
Marta Struga

Purpose: To assess cytotoxic effect of ciprofloxacin conjugates with fatty acids on prostate cancer cells (LNCaP and DU-145) with different hormone sensitivity, based on previous promising results from the PC3 cells. Methods: Cytotoxicity were estimated using MTT and LDH tests, whereas its mechanisms were estimated by apoptosis and IL-6 assays. The intensity of proteins involved in lipid metabolism was determined using ML-CS assay. Results: The hormone insensitive DU-145 cells were more vulnerable than the hormone sensitive LNCaP cells. The IC50 values for oleic (4), elaidic (5) and docosahexaenoic acid (8) conjugates were 20.2 µM, 17.8 µM and 16.5 µM, respectively, in DU-145 cells, whereas in LNCaP cells IC50 exceeded 20 µM. The strong conjugate cytotoxicity was confirmed in the LDH test, the highest (70.8%) for compound (5) and 64.2% for compound (8) in DU-145 cells. This effect was weaker for LNCaP cells (around 60%). The cytotoxic effect of unconjugated ciprofloxacin and fatty acids was weaker. The early apoptosis was predominant in LNCaP while in DU-145 cells both early and late apoptosis was induced. The tested conjugates decreased IL-6 release in both cancer cell lines by almost 50%. Proteomic analysis indicated influence of the ciprofloxacin conjugates on lipid metabolic proteins in prostatic cancer. Conclusion: Our findings suggested the cytotoxic potential of ciprofloxacin conjugates with reduction in proteins involved in prostate cancer progress.


Endocrinology ◽  
2006 ◽  
Vol 147 (10) ◽  
pp. 4883-4892 ◽  
Author(s):  
Rishu Guo ◽  
Elizabeth A. Kasbohm ◽  
Puneeta Arora ◽  
Christopher J. Sample ◽  
Babak Baban ◽  
...  

The bioactive phospholipid lysophosphatidic acid (LPA) promotes cell proliferation, survival, and migration by acting on cognate G protein-coupled receptors named LPA1, LPA2, and LPA3. We profiled gene expression of LPA receptors in androgen-dependent and androgen-insensitive prostate cancer cells and found that LPA1 gene is differentially expressed in androgen-insensitive and LPA-responsive but not androgen-dependent and LPA-resistant cells. In human prostate specimens, expression of LPA1 gene was significantly higher in the cancer compared with the benign tissues. The androgen-dependent LNCaP cells do not express LPA1 and do not proliferate in response to LPA stimulation, implying LPA1 transduces cell growth signals. Accordingly, stable expression of LPA1 in LNCaP cells rendered them responsive to LPA-induced cell proliferation and decreased their doubling time in serum. Implantation of LNCaP-LPA1 cells resulted in increased rate of tumor growth in animals compared with those tumors that developed from the wild-type cells. Growth of LNCaP cells depends on androgen receptor activation, and we show that LPA1 transduces Gαi-dependent signals to promote nuclear localization of androgen receptor and cell proliferation. In addition, treatment with bicalutamide inhibited LPA-induced cell cycle progression and proliferation of LNCaP-LPA1 cells. These results suggest the possible utility of LPA1 as a drug target to interfere with progression of prostate cancer.


2014 ◽  
Vol 21 (3) ◽  
pp. 473-486 ◽  
Author(s):  
Sheeba Jacob ◽  
S Nayak ◽  
Gwendolyn Fernandes ◽  
R S Barai ◽  
S Menon ◽  
...  

Zinc finger E-box-binding protein 2 (ZEB2) is known to help mediate the epithelial-to-mesenchymal transition, and thereby it facilitates cancer metastasis. This study was initiated to explore whether ZEB2 expression differs in prostate cancer (PCa,n=7) and benign prostatic hyperplasia (BPH,n=7) tissues. In PCa tissues, the levels of both immunoreactive ZEB2 and androgen receptor (AR) were found to be significantly higher (P<0.05) when compared with BPH tissues. Co-regulation of AR and ZEB2 prompted us to investigate the role of androgenic stimuli in ZEB2 expression. ZEB2 expression was found to be significantly (P<0.05) upregulated after androgen stimulation and downregulated following AR silencing in LNCaP cells, an androgen-dependent PCa cell line. This finding suggested AR as a positive regulator of ZEB2 expression in androgen-dependent cells. Paradoxically, androgen-independent (AI) cell lines PC3 and DU145, known to possess low AR levels, showed significantly (P<0.05) higher expression of ZEB2 compared with LNCaP cells. Furthermore, forced expression of AR in PC3 (PC3-AR) and DU145 (DU-AR) cells led to reductions in ZEB2 expression, invasiveness, and migration. These cells also exhibited an increase in the levels of E-cadherin (a transcriptional target of ZEB2). Co-transfection ofARandZEB2cDNA constructs prevented the decline in invasiveness and migration to a significant extent. Additionally, ZEB2 downregulation was associated with an increase in miR200a/miR200b levels in PC3-AR cells and with a decrease in miR200a/miR200b levels in AR-silenced LNCaP cells. Thus, AR acts as a positive regulator of ZEB2 expression in androgen-dependent cells and as a negative regulator in AI PCa cells.


Endocrinology ◽  
2007 ◽  
Vol 148 (10) ◽  
pp. 4716-4726 ◽  
Author(s):  
Sumudra Periyasamy ◽  
Manya Warrier ◽  
Manoranjani P. M. Tillekeratne ◽  
Weinian Shou ◽  
Edwin R. Sanchez

The androgen receptor (AR) contributes to growth of prostate cancer even under conditions of androgen ablation. Thus, new strategies to target AR activity are needed. The AR interacts with the immunophilin FK506-binding protein 52 (FKBP52), and studies in the FKBP52 knockout mouse have shown that this protein is essential to AR activity in the prostate. Therefore, we tested whether the immunophilin ligand FK506 affected AR activity in prostate cancer cell lines. We also tested the hypothesis that the AR interacts with another immunophilin, cyclophilin 40 (Cyp40), and is regulated by its cognate ligand cyclosporin A (CsA). We show that levels of FKBP52, FKBP51, Cyp40, and a related co-chaperone PP5 were much higher in prostate cancer cells lines [(LNCaP), PC-3, and DU145] compared with primary prostate cells, and that the AR of LNCaP cells can interact with Cyp40. In the absence of androgen, CsA caused inhibition of cell growth in the AR-positive LNCaP and AR-negative PC-3 and DU145 cell lines. Interestingly, FK506 only inhibited LNCaP cells, suggesting a dependence on the AR for this effect. Both CsA and FK506 inhibited growth without inducing apoptosis. In LNCaP cells, CsA completely blocked androgen-stimulated growth, whereas FK506 was partially effective. Further studies in LNCaP cells revealed that CsA and FK506 were able to block or attenuate several stages of AR signaling, including hormone binding, nuclear translocation, and activity at several AR-responsive reporter and endogenous genes. These findings provide the first evidence that CsA and FK506 can negatively modulate proliferation of prostate cells in vitro. Immunophilins may now serve as new targets to disrupt AR-mediated prostate cancer growth.


2007 ◽  
Vol 25 (18_suppl) ◽  
pp. 21135-21135
Author(s):  
M. Toledo Lobo ◽  
M. Arenas Jiménez ◽  
L. Huertas Martínez ◽  
S. Sacristán lópez ◽  
A. Moyano Jato ◽  
...  

21135 Background: The mechanism through wich zoledronic acid exerts its activity is poorly understood. Low density lipoprotein receptor (LDLR) and scavenger receptor class B type 1 (SRBI) overproduction is an important mechanism in cancer cells for obtaining more essential fatty acids and cell growth. The effects of in vitro zoledronate treatment on the lipid metabolism of prostate cancer cell lines were studied. Methods: Three prostatic cancer cell lines, androgen insensitive PC3, androgen dependent low-passage (LP) LNCaP and androgen independent high-passage (HP) LNCaP cells were studied. Cells were plated either in RPMI with 5% foetal calf serum and lipoprotein depleted serum (LPDS) and were treated with zoledronate at different concentrations. The lipid transporters profile was analyzed by western blotting for LDLR and SRB1. Results: The same LDLR bands profile was observed in all cell lines, 160 and 105 kDa. The basal levels of LDLR were higher in the PC3 cells. Zoledronate therapy induced LDLR expression in all cell lines but PC3 were less sensitive to this effect. Cells cultured with LPDS showed an enhanced expression of LDLR and PC3 cells were less sensitive to this effect. HP LNCaP cells were the most affected by lipoprotein deprivation however this effect diminished 72 hours after treatment. The bands profile for SRBI consisted of a 65 kDa predominant band and a 40 kDa band in both LP/HP LNCaP cells. In PC3 cells main band was located in 65 kDa and accessory band in 30kDa. The basal levels of the 65kDa band were higher in HP than in LP LNCaP or PC3 cells and zoledronate therapy caused a dose- dependent induction in HP LNCaP and dose-dependent reduction in PC3 cells, LP LNCaP cells were resistant to the treatment. LPDS induced SRBI levels in all cell lines inverting the effect caused by zoledronate in HP LNCaP cells in complete culture medium and at high doses (100μM) a complete inhibition of SRBI protein was found. Low molecular weight bands changed in the same way as the 65 kDa band. Conclusions: LDL-R and SRBI have been isolated in prostate cancer cell lines. Based on previous cell growth studies, the lipid transporters profile might be significantly involved in the resistance to zoledronate therapy. Lipoprotein regulation pathways should be considered in the therapy of metastatic prostate cancer. No significant financial relationships to disclose.


2011 ◽  
Vol 29 (7_suppl) ◽  
pp. 32-32
Author(s):  
P. Sluka ◽  
G. Whitty ◽  
I. D. Davis

32 Background: Interactions between cancer cells and their microenvironment affect the establishment and metastasis of cancer. The most common site of prostate cancer (PC) metastasis is bone. This study examined the effects of selected factors known to be produced by bone stroma (EGF, aFGF, HGF, β-NGF, TGF-β, and TNFα) on the proliferation of PC cells. The effect of cell culture medium (CM) conditioned by osteoblasts (OBCM) was also examined. Methods: The PC-derived cell lines PC3, LNCaP, and DU145 were used. Expression of receptors for the above-mentioned cytokines was assessed using real-time RT-PCR. After 5 days of continuous cytokine treatment, proliferation was assessed by MTS conversion, and cell survival and apoptosis was assessed by 7-AAD staining and flow cytometry. OBCM was generated using the HOS, MG63, and SaOs2 cell lines. CM from the HT1080 fibrosarcoma cell line was used as a non-bone control. Results: The PC cell lines expressed receptors for all of the cytokines examined at the mRNA level. LNCaP cell proliferation was increased by aFGF and decreased by TGF-β. Treatment with TNFα decreased proliferation of all PC cell lines. These effects were not due to apoptosis. EGF, HGF, and β-NGF did not affect proliferation of any line despite receptor expression. OBCM increased proliferation of PC3 and DU145 cells but not LNCaP cells, while HT1080 CM did not affect proliferation of any line. Conclusions: PC cells are able to respond to defined bone-derived factors and that the nature of this response varies between individual cancers. Acidic FGF increased proliferation of LNCaP cells while TGF-β and TNFα decreased proliferation of LNCaP and all cell lines, respectively; an effect not mediated by apoptosis. Current studies are examining the effect of these cytokines on other functional parameters (cell survival, adhesion and migration) and on primary PC epithelial cells. No significant financial relationships to disclose.


2019 ◽  
Vol 8 (9) ◽  
pp. 1400 ◽  
Author(s):  
Gómez-Gómez E. ◽  
Jiménez-Vacas J. M. ◽  
Pedraza-Arévalo S. ◽  
López-López F. ◽  
Herrero-Aguayo V. ◽  
...  

Engrailed variant-2 (EN2) has been suggested as a potential diagnostic biomarker; however, its presence and functional role in prostate cancer (PCa) cells is still controversial or unknown. Here, we analyzed 1) the expression/secretion profile of EN2 in five independent samples cohorts from PCa patients and controls (prostate tissues and/or urine) to determine its utility as a PCa biomarker; and 2) the functional role of EN2 in normal (RWPE1) and tumor (LNCaP/22Rv1/PC3) prostate cells to explore its potential value as therapeutic target. EN2 was overexpressed in our two cohorts of PCa tissues compared to control and in tumor cell lines compared with normal-like prostate cells. This profile was corroborated in silico in three independent data sets [The Cancer Genome Atlas(TCGA)/Memorial Sloan Kettering Cancer Center (MSKCC)/Grasso]. Consistently, urine EN2 levels were elevated and enabled discrimination between PCa and control patients. EN2 treatment increased cell proliferation in LNCaP/22Rv1/PC3 cells, migration in RWPE1/PC3 cells, and PSA secretion in LNCaP cells. These effects were associated, at least in the androgen-sensitive LNCaP cells, with increased AKT and androgen-receptor phosphorylation levels and with modulation of key cancer-associated genes. Consistently, EN2 treatment also regulated androgen-receptor activity (full-length and splicing variants) in androgen-sensitive 22Rv1 cells. Altogether, this study demonstrates the potential utility of EN2 as a non-invasive diagnostic biomarker for PCa and provides novel and valuable information to further investigate its putative utility to develop new therapeutic tools in PCa.


2011 ◽  
Vol 300 (5) ◽  
pp. E902-E908 ◽  
Author(s):  
Fu-Ning Hsu ◽  
Min-Shiou Yang ◽  
Eugene Lin ◽  
Chun-Fu Tseng ◽  
Ho Lin

Androgen ablation therapy is the most common strategy for suppressing prostate cancer progression; however, tumor cells eventually escape androgen dependence and progress to an androgen-independent phase. The androgen receptor (AR) plays a pivotal role in this transition. To address this transition mystery in prostate cancer, we established an androgen-independent prostate cancer cell line (LNCaPdcc), by long-term screening of LNCaP cells in androgen-deprived conditions, to investigate changes of molecular mechanisms before and after androgen withdrawal. We found that LNCaPdcc cells displayed a neuroendocrine morphology, less aggressive growth, and lower expression levels of cell cycle-related factors, although the cell cycle distribution was similar to parental LNCaP cells. Notably, higher protein expression of AR, phospho-Ser81-AR, and PSA in LNCaPdcc cells were observed. The nuclear distribution and protein stability of AR increased in LNCaPdcc cells. In addition, cell proliferation results exhibited the biphasic nature of the androgen (R1881) effect in two cell lines. On the other hand, LNCaPdcc cells expressed higher levels of Her2, phospho-Tyr1221/1222-Her2, ErbB3, and ErbB4 proteins than parental LNCaP cells. These two cell lines exhibited distinct responses to Her2 activation (by heregulin treatment) on Her2 phosphorylation and Her2 inhibition (by AG825 or Herceptin treatments) on proliferation. In addition, the Her2 inhibitor more effectively caused AR degradation and diminished AR Ser81 phosphorylation in LNCaPdcc cells. Taken together, our data demonstrate that Her2 plays an important role in the support of AR protein stability in the transition of androgen requirement in prostate cancer cells. We hope these findings will provide novel insight into the treatment of hormone-refractory prostate cancer.


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