• BMB Reports
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• v.54 no.2
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• pp.130-135
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• 2021

Voltage-gated potassium (Kv) channels are involved in many important cellular functions and play pivotal roles in cancer progression. The expression level of Kv2.1 was observed to be higher in the highly metastatic prostate cancer cells (PC-3), specifically in their membrane, than in immortalized prostate cells (WPMY-1 cells) and comparatively less metastatic prostate cancer cells (LNCaP and DU145 cells). However, Kv2.1 expression was significantly decreased when the cells were treated with antioxidants, such as N-acetylcysteine or ascorbic acid, implying that the highly expressed Kv2.1 could detect reactive oxygen species (ROS) in malignant prostate cancer cells. In addition, the blockade of Kv2.1 with stromatoxin-1 or siRNA targeting Kv2.1 significantly inhibited the migration of malignant prostate cancer cells. Our results suggested that Kv2.1 plays an important role as a ROS sensor and that it is a promising therapeutic molecular target in metastasis of prostate cancer.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.6
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• pp.2941-2946
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• 2016

Background: The limitations of total serum PSA values remain problematic, especially after an initial negative prostate biopsy. In this prospective study of Chilean men with a continued suspicion of prostate cancer due to a persistently elevated total serum PSA, abnormal digital rectal examination and initial negative prostate biopsy were compared with the use of the on-line Chun nomagram, detection of primary malignant circulating prostate cells (CPCs) and free percent PSA to predict a positive second prostate biopsy. We hypothesized that men negative for circulating prostate cells have a small risk of clinically significant prostate cancer and thus may be conservatively observed. Men positive for circulating prostate cells should undergo biopsy to confirm prostate cancer. Materials and Methods: Consecutive men with a continued suspicion of prostate cancer underwent 12 core TRUS prostate biopsy; age, total serum PSA and percentage free PSA and Chun nomagram scores were registered. Immediately before biopsy an 8ml blood simple was taken to detect primary mCPCs. Mononuclear cells were obtained by differential gel centrifugation and identified using double immunostaining with anti-PSA and anti-P504S. Biopsies were classifed as cancer/no-cancer, mCPC detecton test as negative/positive and the total number of cells/8ml registered. Areas under the curve (AUC) for percentage free PSA, Chun score and CPCs were calculated and compared. Diagnostic yields were calculated with reference to the number of possible biopsies that could be avoided and the number of clinically significant cancers that would be missed. Results: A total of 164 men underwent a second biopsy; 41 (25%) had cancer; the AUCs were 0.65 for free PSA, 0.76 for the Chun score and 0.87 for CPC detection, the last having a significantly superior prediction value (p=0.01). Using cut off values of free PSA <10%, Chun score >50% and ${\geq}1$ CPC detected, CPC detection had a higher diagnostic yield. Some 4/41 cancers complied with the criteria for active surveillance, free PSA and the Chun score missed a higher number of significant cancers when compared with CPC detection. Conclusions: Primary CPC detection outperformed the use of free PSA and the Chun nomagram in predicting clinically significant prostate cancer at repeat prostate biopsy.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.16
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• pp.7123-7127
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• 2015

Purpose: To determine the utility of secondary circulating prostate cells for predicting early biochemical failure after radical prostatectomy for prostate cancer and compare the results with the Walz nomagram. Materials and Methods: A single centre, prospective study of men with prostate cancer treated with radical prostatectomy between 2004 and 2014 was conducted, with registration of clinical-pathological details, total serum PSA pre-surgery, Gleason score, extracapsular extension, positive surgical margins, infiltration of lymph nodes, seminal vesicles and pathological stage. Secondary circulating prostate cells were obtained using differential gel centrifugation and assessed using standard immunocytochemistry with anti-PSA. Biochemical failure was defined as a PSA >0.2ng/ml, predictive values werecalculated using the Walz nomagram and CPC detection. Results: A total of 326 men participated, with a median follow up of 5 years; 64 had biochemical failure within two years. Extracapsular extension, positive surgical margins, pathological stage, Gleason score ${\geq}8$, infiltration of seminal vesicles and lymph nodes were all associated with higher risk of biochemical failure. The discriminative value for the nomogram and circulating prostate cells was high (AUC >0.80), predictive values were higher for circulating prostate cell detection, with a negative predictive value of 99%, sensitivity of 96% and specificity of 75%. Conclusions: The nomagram had good predictive power to identify men with a high risk of biochemical failure within two years. The presence of circulating prostate cells had the same predictive power, with a higher sensitivity and negative predictive value. The presence of secondary circulating prostate cells identifies a group of men with a high risk of early biochemical failure. Those negative for secondary CPCs have a very low risk of early biochemical failure.

• Biomolecules & Therapeutics
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• v.22 no.5
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• pp.426-430
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• 2014

Prostate cancer is the most frequently diagnosed cancer. Although prostate tumors respond to androgen ablation therapy at an early stage, they often acquire the potential of androgen-independent growth. Elevated transcriptional activity of androgen receptor (AR) and/or signal transducer and activator of transcription-3 (STAT3) contributes to the proliferation of prostate cancer cells. In the present study, we examined the effect of resveratrol, a phytoalexin present in grapes, on the reporter gene activity of AR and STAT3 in human prostate cancer (LNCaP-FGC) cells stimulated with interleukin-6 (IL-6) and/or dihydrotestosterone (DHT). Our study revealed that resveratrol suppressed the growth of LNCaP-FGC cells in a time- and concentration-dependent manner. Whereas the AR transcriptional activity was induced by treatment with either IL-6 or DHT, the STAT3 transcriptional activity was induced only by treatment with IL-6 but not with DHT. Resveratrol significantly attenuated IL-6-induced STAT3 transcriptional activity, and DHT- or IL-6-induced AR transcriptional activity. Treatment of cells with DHT plus IL-6 significantly increased the AR transcriptional activity as compared to DHT or IL-6 treatment alone and resveratrol markedly diminished DHT plus IL-6-induced AR transcriptional activity. Furthermore, the production of prostate-specific antigen (PSA) was decreased by resveratrol in the DHT-, IL-6- or DHT plus IL-6-treated LNCaP-FGC cells. Taken together, the inhibitory effects of resveratrol on IL-6- and/or DHT-induced AR transcriptional activity in LNCaP prostate cancer cells are partly mediated through the suppression of STAT3 reporter gene activity, suggesting that resveratrol may be a promising therapeutic choice for the treatment of prostate cancer.

• Biomolecules & Therapeutics
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• v.28 no.2
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• pp.195-201
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• 2020

Prostate cancer is one of the most common cancers in men. Choline PET or PET/CT has been used to visualize prostate cancer, and high levels of choline accumulation have been observed in tumors. However, the uptake system for choline and the functional expression of choline transporters in prostate cancer are not completely understood. In this study, the molecular and functional aspects of choline uptake were investigated in the LNCaP prostate cancer cell line along with the correlations between choline uptake and cell viability in drug-treated cells. Choline transporter-like protein 1 (CTL1) and CTL2 mRNA were highly expressed in LNCaP cells. CTL1 and CTL2 were located in the plasma membrane and mitochondria, respectively. [³H]Choline uptake was mediated by a single Na⁺-independent, intermediate-affinity transport system in the LNCaP cells. The anticancer drugs, flutamide and bicalutamide, inhibited cell viability and [³H]choline uptake in a concentration-dependent manner. The correlations between the effects of these drugs on cell viability and [³H]choline uptake were significant. Caspase-3/7 activity was significantly increased by both flutamide and bicalutamide. Furthermore, these drugs decreased CTL1 expression in the prostate cancer cell line. These results suggest that CTL1 is functionally expressed in prostate cancer cells and are also involved in abnormal proliferation. Identification of this CTL1-mediated choline transport system in prostate cancer cells provides a potential new therapeutic target for the treatment of this disease.

• The Journal of Pediatrics of Korean Medicine
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• v.27 no.1
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• pp.59-68
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• 2013

Objectives The aim of this study is to investigate whether hwang-ryun-haedok-tang (HDT) affect proliferations of androgen-dependent LNCaP prostate cancer cells, androgen-independent PC-3, DU-145 prostate cancer cells, MCF-7 human breast cancer cells, A549, NCI-H292 human pulmonary cancer cells and K-562 human chronic myelogenous leukemia cells. Materials and Methods Effects of HDT on proliferations of each cancer cell line were investigated. 20,000 cells/well were plated in each well of 96-well culture plate. After 24 hrs, 0.01-10% of HDT in culture medium was added to cancer cells. The number of cells was counted by using SRB assay or direct cell counting method after 72 hours from drug treatment. Effect of baicalein or berebrine on proliferation was assessed according to the same method. Results (1) HDT inhibited proliferations of LNCaP, PC-3 and DU-145 prostate cancer cells. (2) HDT inhibited proliferation of MCF-7 breast cancer cells. (3) HDT also inhibited proliferations of A549, NCI-H292 pulmonary cancer cells and K-562 chronic myelogenous leukemia cells. (4) Baicalein and berberine also showed inhibitory effects on proliferations of prostate and breast cancer cells. Conclusion : HDT inhibited proliferations of human prostate, breast, pulmonary and blood cancer cells. These results suggest us the potential use of HDT as a chemopreventive or chemotherapeutic agent. Effect of HDT on human cancer should be further investigated using in vivo experimental models that can reflect pathophysiology of human cancer through another studies.

• Fisheries and Aquatic Sciences
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• v.24 no.1
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• pp.1-9
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• 2021

Human prostate cancer is the second most frequently diagnosed cancer worldwide, and its incidence rate continues to increase. Advanced prostate cancer is more difficult to treat than early forms due to its chemotherapy resistance. There is need for more effective agents that can inhibit the progression of advanced prostate cancer. Demethoxyfumitremorgin C (DMFTC) was isolated from the fermentation extract of the marine fungus Aspergillus fumigatus. Antiproliferative activity of DMFTC against human prostate cancer PC3 cells was examined through cell cycle analysis by flow cytometry, the fluorescent nuclear imaging analysis with propidium iodide (PI), and proteins expression related to cell cycle arrest and apoptosis were investigated via Western blotting. DMFTC inhibited PC3 cells growth through G1 phase cell cycle arrest and apoptosis induction. It activated the tumor suppressor p53 and the Cdk inhibitor p21, which regulate the cell progression into the G1 phase. Additionally, PI-positive late apoptotic non-viable cells were increased and the expression levels of the G1-positive downstream regulators cyclin D, cyclin E, Cdk2, and Cdk4 were decreased by DMFTC treatment. These results suggest that DMFTC induces G1 arrest and apoptosis induction through regulation of p53/p21-dependent cyclin-Cdk complexes, and it may be a useful therapeutic agent for the treatment of human advanced prostate cancer.

• Biomolecules & Therapeutics
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• v.21 no.1
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• pp.49-53
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• 2013

A number of naturally-occurring or synthetic chemicals have been reported to exhibit prostate chemopreventive effects. Synthetic $5{\alpha}$-reductase (5-AR) inhibitors, e.g. finasteride and durasteride, gained special interests as possible prostate chemopreventive agents. Indeed, two large-scale epidemiological studies have demonstrated that finasteride or durasteride significantly reduced the incidence of prostate cancer formation in men. However, these studies have raised an unexpected concern; finasteride and durasteride increased the occurrence of aggressive prostate tumor formation. In the present study, we have observed that treatment of finasteride did not affect the growth of androgen-refractory PC-3 prostate cancer cells. Finasteride also failed to induce apoptosis or affect the expression of proto-oncogenes in PC-3 cells. Interestingly, we found that treatment of finasteride induced the expression of Nrf2 and HO-1 proteins in PC-3 cells. In particular, basal level of Nrf2 protein was higher in androgen-refractory prostate cancer cells, e.g. DU-145 and PC-3 cells, compared with androgen-responsive prostate cancer cells, e.g. LNCaP cells. Also, treatment of finasteride resulted in a selective induction of Nrf2 protein in DU-145 and PC-3 cells, but not in LNCaP cells. In view of the fact that upregulation of Nrf2-mediated phase II cytoprotective enzymes contribute to attenuating tumor promotion in normal cells, but, on the other hand, confers a selective advantage for cancer cells to proliferate and survive against chemical carcinogenesis and other forms of toxicity, we propose that finasteride-mediated induction of Nrf2 protein might be responsible, at least in part, for an increased risk of high-grade prostate tumor formation in men.

• Journal of Physiology & Pathology in Korean Medicine
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• v.23 no.5
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• pp.1154-1160
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• 2009

Androgen receptors (AR) play a crucial role in the development and progression of prostate cancer. Many studies have suggested that prostate cancer cell proliferation is inhibited by AR downregulation, and it has been reported that Takrisodokyeum (TRSDY) induced apoptotic cell death and suppressed tumorigenesis in human leukemia cells. Therefore, this study was conducted to elucidate the mechanism by which TRSDY affects cell growth and AR expression in androgen-dependent prostate cancer cells (LNCaP cells). We investigated the proliferation and apoptosis of LNCaP cells using MTT and DNA fragmentation assays. In addition, we used western blot analysis to assess the effects of TRSDY on the expression of the AR target gene, prostate-specific antigen (PSA). Furthermore, the mechanism of AR downregulation by TRSDY was investigated using EMSA to analyze the binding activity of AR to androgen response elements (ARE). TRSDY significantly suppressed proliferation and induced apoptosis in LNCaP cells. In addition, TRSDY-induced apoptotic cell death was accompanied by activation of caspase-3 and cleavage of its substrate, poly(ADP-ribose) polymerase. TRSDY also inhibited the constitutively expressed- or 5a-dihydrotestosterone (DHT)-induced AR/PSA protein levels. However, these effects were mediated by inhibition of the binding of AR to ARE. TRSDY-mediated AR/PSA downregulation contributes to the inhibition of cell proliferation and the induction of apoptosis in LNCaP human prostate cancer cells. Our findings suggest that TRSDY may be used as a chemopreventive or chemotherapeutic agent for the treatment of prostate cancer.

• Molecules and Cells
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• v.42 no.1
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• pp.17-27
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• 2019

Ubiquitin-specific protease 44 (USP44) has been implicated in tumor progression and metastasis across various tumors. However, the function of USP44 in prostate cancers and regulatory mechanism of histone-modifying enzymes by USP44 in tumors is not well-understood. Here, we found that enhancer of zeste homolog 2 (EZH2), a histone H3 lysine 27 methyltransferase, is regulated by USP44. We showed that EZH2 is a novel target of USP44 and that the protein stability of EZH2 is upregulated by USP44-mediated deubiquitination. In USP44 knockdown prostate cancer cells, the EZH2 protein level and its gene silencing activity were decreased. Furthermore, USP44 knockdown inhibited the tumorigenic characteristics and cancer stem cell-like behaviors of prostate cancer cells. Inhibition of tumorigenesis caused by USP44 knockdown was recovered by ectopic introduction of EZH2. Additionally, USP44 regulates the protein stability of oncogenic EZH2 mutants. Taken together, our results suggest that USP44 promotes the tumorigenesis of prostate cancer cells partly by stabilizing EZH2 and that USP44 is a viable therapeutic target for treating EZH2-dependent cancers.