scholarly journals DNA licensing as a novel androgen receptor mediated therapeutic target for prostate cancer

2009 ◽  
Vol 16 (2) ◽  
pp. 325-332 ◽  
Author(s):  
Jason M D'Antonio ◽  
Donald J Vander Griend ◽  
John T Isaacs

During middle G1 of the cell cycle origins of replication orchestrate the ordered assembly of the pre-replication complex (pre-RC), allowing licensing of DNA required for DNA replication. Cyclin-dependent kinase activation of the pre-RC facilitates the recruitment of additional signaling factors, which triggers DNA unwinding and replication, while limiting such DNA replication to once and only once per cell cycle. For both the normal and malignant prostate, androgen is the major stimulator of cell proliferation and thus DNA replication. In both cases, the binding of androgen to the androgen receptor (AR) is required. However, the biochemical cascade involved in such AR-stimulated cell proliferation and DNA synthesis is dramatically different in normal versus malignant prostate cells. In normal prostate, AR-stimulated stromal cell paracrine secretion of andromedins stimulates DNA replication within prostatic epithelial cells, in which AR functions as a tumor suppressor gene by inducing proliferative quiescence and terminal differentiation. By direct contrast, nuclear AR in prostate cancer cells autonomously stimulates continuous growth via incorporation of AR into the pre-RC. Such a gain of function by AR-expressing prostate cancer cells requires that AR be efficiently degraded during mitosis since lack of such degradation leads to re-licensing problems, resulting in S-phase arrest during the subsequent cell cycle. Thus, acquisition of AR as part of the licensing complex for DNA replication represents a paradigm shift in how we view the role of AR in prostate cancer biology, and introduces a novel vulnerability in AR-expressing prostate cancer cells apt for therapeutic intervention.

2021 ◽  
Vol 14 (2) ◽  
pp. 103
Author(s):  
Zohaib Rana ◽  
Joel D. A. Tyndall ◽  
Muhammad Hanif ◽  
Christian G. Hartinger ◽  
Rhonda J. Rosengren

Androgen receptor (AR)-null prostate tumors have been observed in 11–24% of patients. Histone deacetylases (HDACs) are overexpressed in prostate tumors. Therefore, HDAC inhibitors (Jazz90 and Jazz167) were examined in AR-null prostate cancer cell lines (PC3 and DU145). Both Jazz90 and Jazz167 inhibited the growth of PC3 and DU145 cells. Jazz90 and Jazz167 were more active in PC3 cells and DU145 cells in comparison to normal prostate cells (PNT1A) and showed a 2.45- and 1.30-fold selectivity and higher cytotoxicity toward DU145 cells, respectively. Jazz90 and Jazz167 reduced HDAC activity by ~60% at 50 nM in PC3 lysates. At 4 μM, Jazz90 and Jazz167 increased acetylation in PC3 cells by 6- to 8-fold. Flow cytometry studies on the cell phase distribution demonstrated that Jazz90 causes a G0/G1 arrest in AR-null cells, whereas Jazz167 leads to a G0/G1 arrest in DU145 cells. However, apoptosis only occurred at a maximum of 7% of the total cell population following compound treatments in PC3 and DU145 cells. There was a reduction in cyclin D1 and no significant changes in bcl-2 in DU145 and PC3 cells. Overall, the results showed that Jazz90 and Jazz167 function as cytostatic HDAC inhibitors in AR-null prostate cancer cells.


2021 ◽  
pp. 1-9
Author(s):  
Yuxin Li ◽  
Xiaohong Zhuang ◽  
Li Zhuang ◽  
Hongjian Liu

This paper aimed at investigating AS1 expression in prostate cancer (PCa) and its effects on the proliferation and invasion of prostate cancer cells (PCCs). The prostate tissues and the matched adjacent normal prostate tissues excised and preserved during radical prostatectomy in our hospital were collected. The LncRNA NCK1-AS1 expression was detected. PCa patients were followed up for three years to analyze their prognosis. The correlation of LncRNA NCK1-AS1 expression with clinicopathological features was analyzed. Human normal prostate cells and human PCCs were selected, in which LncRNA NCK1-AS1 expression was tested to screen and then transfect the cells. Cell proliferation, invasion and migration were detected. Cell cycles and apoptosis were analyzed. Compared with the adjacent normal tissues, LncRNA NCK1-AS1 was highly expressed in the prostate cancer tissues. Its expression was remarkably different in those with different stages of TNM and with lymphatic metastasis or not. The prognosis of patients with high LncRNA NCK1-AS1 expression was remarkably poorer than that of those with low expression. Compared with the human normal prostate cells, LncRNA NCK1-AS1 expression in the human PCCs remarkably rose, with the greatest difference in 22Rv1 cells. Compared with the Blank group, cell proliferation and the number of plate cloned cells remarkably reduced in the sh-NCK1-AS1 group. Additionally, in this group, the number of invasive and migratory cells remarkably reduced; the expression of invasion-related protein E-cadherin remarkably rose but that of MMP-2 remarkably reduced; cell cycles were arrested and the expression of cycle-related proteins (CDK4, CDK6, cyclin D1) remarkably reduced; the apoptotic rate and the expression of apoptosis-related protein Bax remarkably rose. LncRNA NCK1-AS1 is highly expressed in PCa, so its down-regulation can inhibit PCCs from proliferating and reduce the number of invasive cells.


Planta Medica ◽  
2019 ◽  
Vol 85 (11/12) ◽  
pp. 997-1007 ◽  
Author(s):  
Katerina Gioti ◽  
Anastasia Papachristodoulou ◽  
Dimitra Benaki ◽  
Sophia Havaki ◽  
Apostolos Beloukas ◽  
...  

AbstractSilymarin-enriched extract (SEE) is obtained from Silybum marianum (Asteraceae). Doxorubicin (DXR) is a widely used chemotherapeutical yet with severe side effects. The goal of the present study was to assess the pharmacologic effect of SEE and its bioactive components silibinin and silychristine when administrated alone or in combination with DXR in the human prostate cancer cells (PC-3). PC-3 cells were treated with SEE, silibinin (silybins A and B), silychristine, alone, and in combination with DXR, and cell proliferation was assessed by the MTT assay. Cell cycle, apoptosis, and autophagy rate were assessed by flow cytometry. Expression levels of autophagy-related genes were quantified by qRT-PCR, ELISA and western blot while transmission electron microscopy was performed to reveal autophagic structures. Finally, NMR spectrometry was used to identify specific metabolites related to autophagy. SEE inhibited PC-3 cell proliferation in a dose-dependent manner while the co-treatment (DXR-SEE) revealed an additive cytotoxic effect. Cell cycle, apoptosis, and autophagy variations were observed in addition to altered expression levels of autophagy related genes (LC3, p62, NBR1, Beclin1, ULK1, AMBRA1), while several modifications in autophagic structures were identified after DXR-SEE co-treatment. Furthermore, treated cells showed a different metabolic profile, with significant alterations in autophagy-related metabolites such as branched-chain amino acids. In conclusion, the DXR-SEE co-treatment provokes perturbations in the autophagic mechanism of prostate cancer cells (PC-3) compared to DXR treatment alone, causing an excessive cell death. These findings propose the putative use of SEE as an adjuvant cytotoxic agent.


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.


2015 ◽  
Vol 26 (11) ◽  
pp. 1971-1984 ◽  
Author(s):  
Julia Lindqvist ◽  
Susumu Y. Imanishi ◽  
Elin Torvaldson ◽  
Marjo Malinen ◽  
Mika Remes ◽  
...  

Contrary to cell cycle–associated cyclin-dependent kinases, CDK5 is best known for its regulation of signaling processes in differentiated cells and its destructive activation in Alzheimer's disease. Recently, CDK5 has been implicated in a number of different cancers, but how it is able to stimulate cancer-related signaling pathways remains enigmatic. Our goal was to study the cancer-promoting mechanisms of CDK5 in prostate cancer. We observed that CDK5 is necessary for proliferation of several prostate cancer cell lines. Correspondingly, there was considerable growth promotion when CDK5 was overexpressed. When examining the reasons for the altered proliferation effects, we observed that CDK5 phosphorylates S308 on the androgen receptor (AR), resulting in its stabilization and differential expression of AR target genes including several growth-priming transcription factors. However, the amplified cell growth was found to be separated from AR signaling, further corroborated by CDK5-depdent proliferation of AR null cells. Instead, we found that the key growth-promoting effect was due to specific CDK5-mediated AKT activation. Down-regulation of CDK5 repressed AKT phosphorylation by altering its intracellular localization, immediately followed by prominent cell cycle inhibition. Taken together, these results suggest that CDK5 acts as a crucial signaling hub in prostate cancer cells by controlling androgen responses through AR, maintaining and accelerating cell proliferation through AKT activation, and releasing cell cycle breaks.


2010 ◽  
Vol 17 (1) ◽  
pp. 5 ◽  
Author(s):  
Srinivas Rajamahanty ◽  
Catherine Alonzo ◽  
Shahrad Aynehchi ◽  
Muhammad Choudhury ◽  
Sensuke Konno

2020 ◽  
Author(s):  
Meng Ning ◽  
Zhifa Zhang ◽  
Lihui Yu ◽  
Peiyu Han ◽  
xiaofeng Dai

Abstract BackgroundAndrogen receptor-independent prostate cancers do not respond to androgen blockage therapies and suffer from high recurrence rate. We aim to contribute to the establishment of novel therapeutic approaches against such malignancies.Methods We examined whether and how cold atmospheric plasma delivers selectivity against AR-independent prostate cancers using human normal epithelial prostatic cells PNT1A and AR-negative DU145 prostate cancer cells.ResultsWe show that cold atmospheric plasma could selectively halt cell proliferation and migration in androgen receptor-independent cells as a result of induced cell apoptosis and G0/G1 stage cell cycle arrest, and such outcomes were achieved through modulations on the MAPK and NF-kB pathways in response to physical plasma induced intracellular redox level. ConclusionOur study reports cold atmospheric plasma induced reduction on the proliferation and migration of androgen receptor-independent prostate cancer cells that offers novel therapeutic insights on the treatment of such cancers, and provides the first evidence on physical plasma induced cell cycle G0/G1 stage arrest that warrants the exploration on the synergistic use of cold atmospheric plasma and drugs such as chemotherapies in eradicating such cancer cells.


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