Proliferation Of Prostate Carcinoma Cells Research Articles

Oxazolinyl derivatives of androst-16-ene as inhibitors of CYP17A1 activity and prostate carcinoma cells proliferation: Effects of substituents in oxazolinyl moiety

Steroid derivatives modified with nitrogen containing heterocycles are known to inhibit activity of steroidogenic enzymes, decrease proliferation of cancer cells and attract attention as promising anticancer agents. Specifically, 2′-(3β-hydroxyandrosta-5,16-dien-17-yl)-4′,5′-dihydro-1′,3′-oxazole 1a potently inhibited proliferation of prostate carcinoma cells. In this study we synthesized and investigated five new derivatives of 3β-hydroxyandrosta-5,16-diene comprising 4′-methyl or 4′-phenyl substituted oxazolinyl cycle 1 (b–f). Docking of compounds 1 (a–f) to CYP17A1 active site revealed that the presence of substitutents at C4′ atom in oxazoline cycle, as well as C4′ atom configuration, significantly affect docking poses of compounds in the complexes with enzyme. Testing of compounds 1 (a–f) as CYP17A1 inhibitors revealed that the only compound 1a, comprising unsubstituted oxazolinyl moiety, demonstrated strong inhibitory activity, while other compounds 1 (b–f) were slightly active or non active. Compounds 1 (a–f) efficiently decreased growth and proliferation of prostate carcinoma LNCaP and PC-3 cells at 96 h incubation; the effect of compound 1a was the most powerful. Compound 1a efficiently stimulated apoptosis and caused PC-3 cells death, that was demonstrated by a direct comparison of pro-apoptotic effects of compound 1a and abiraterone.

Clinical Significance of High Expression of tRF-Glu-TTC-2 in Prostate Carcinoma and its Effect on Growth.

The tRNA-derived fragments (tRFs) are a new class of regulatory noncoding RNAs and have different biological functions in cancer. This article investigated the expression and clinicopathological significance of tRF-Glu-TTC-2 in prostate carcinoma (PCa), and its effect on tumor growth. Expression profiles of tRFs and tiRNAs were analyzed by tRF and tiRNAs microarray in PCa samples, and then the expression was confirmed by qRT-PCR; RNA in situ hybridization was used to detect the positive expression of tRF-Glu-TTC-2 and to analyze the correlation between the expression level of tRF-Glu-TTC-2 and clinicopathological parameters. CCK-8 experiment was used to detect the effect of tRF-Glu-TTC-2 on the proliferation of PCa cells, and nude mice subcutaneous tumor model was used to detect the effect of tRF-Glu-TTC-2 on the growth of PCa cells. The results showed that tRF-Glu-TTC-2 was mainly positive and its expression level increased in PCa. The high expression was closely related to the tumor size (p < .05). Overexpression of tRF-Glu-TTC-2 promoted the proliferation of PCa cells, and decreased expression of tRF-Glu-TTC-2 inhibited the proliferation of PCa cells (p < .05). The results of subcutaneous tumor transplantation in nude mice showed that the tumor volume and weight of the knockdown group were smaller than those of the control group(all ps < .05). Ki-67 staining showed that the proportion of Ki-67-positive cells in the reduced tRF-Glu-TTC-2 group was lower than that in the control group (p < .05). The tRF-Glu-TTC-2 may be a new oncogene that can promote growth and proliferation of PCa. It provides a new idea for the treatment of PCa.

Hsa_circ_0102485 inhibits the growth of cancer cells by regulating the miR-188–3p/ARID5B/AR axis in prostate carcinoma

BackgroundStudies have shown that circular RNAs (circRNAs) have significant potential as novel molecular markers for the diagnosis, treatment, and prognosis of prostate carcinoma (PCa). However, the role and mechanism of circRNA hsa_circ_0102485 in PCa remains unclear. Materials & methodsThe real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) was used to quantify hsa_circ_0102485 expression in PCa. The potential mechanisms and roles of hsa_circ_0102485 in tumor growth were explored using dual-luciferase-reporter and subcutaneous-xenograft assays, rescue experiments, and immunohistochemical staining. Clinical correlations were assessed by tissue-on-a-chip in-situ hybridization and Fisher’s exact test. ResultsHsa_circ_0102485 expression was decreased in PCa, and overexpression of hsa_circ_0102485 suppressed the proliferation, metastasis, invasion, and antiapoptotic abilities of PCa cells. MicroRNA 188–3p (MiR-188–3p) is a direct target of hsa_circ_0102485, and cotransfection of hsa_circ_0102485 in PCa cells overexpressing miR-188–3p inhibited its promotive effects. Hsa_circ_0102485 indirectly promotes the expression of AT-rich interaction domain 5B (ARID5B) and androgen receptor (AR) by sponging miR-188–3p and inhibiting PCa cell growth. Correlation analysis showed that hsa_circ_0102485 expression in PCa was not significantly correlated with the age, International Society of Urologic Pathologists (ISUP) grade, Gleason score, or lymph node metastasis status of PCa patients. ConclusionHsa_circ_0102485 plays an inhibitory role in PCa by regulating the Mir-188–3p/ARID5B/AR axis and may be a potential diagnostic biomarker and therapeutic target for PCa that requires further study.

Target Protein for Xklp2 Functions as Coactivator of Androgen Receptor and Promotes the Proliferation of Prostate Carcinoma Cells.

The activation of the androgen receptor (AR) pathway is crucial in the progression of human prostate cancer. Results of the present study indicated that the target protein xenopus kinesin-like protein (TPX2) enhanced the transcription activation of AR and promoted the proliferation of LNCaP (ligand-dependent prostate carcinoma) cells. The protein-protein interaction between AR and TPX2 was investigated using coimmunoprecipitation assays. Results of the present study further demonstrated that TPX2 enhanced the transcription factor activation of AR and enhanced the expression levels of the downstream gene prostate-specific antigen (PSA). TPX2 did this by promoting the accumulation of AR in the nucleus and also promoting the recruitment of AR to the androgen response element, located in the promoter region of the PSA gene. Overexpression of TPX2 enhanced both the in vitro and in vivo proliferation of LNCaP cells. By revealing a novel role of TPX2 in the AR signaling pathway, the present study indicated that TPX2 may be an activator of AR and thus exhibits potential as a novel target for prostate carcinoma treatment.

LINC00467 Promotes Prostate Cancer Progression via M2 Macrophage Polarization and the miR-494-3p/STAT3 Axis.

BackgroundThe long non-coding RNA LINC00467 plays a vital role in many malignancies. Nevertheless, the role of LINC00467 in prostate carcinoma (PC) is unknown. Herein, we aimed to explore the mechanism by which LINC00467 regulates PC progression.MethodsWe used bioinformatics analyses and RT-qPCR to investigate the expression of LINC00467 in PC tissues and cells. The function of LINC00467 in the progression of PC was confirmed by loss-of-function experiments. PC cell proliferation was assessed by CCK-8 and EdU assays. The cell cycle progression of PC cells was examined by flow cytometry. Moreover, Transwell assays were used to investigate the migration and invasion of PC cells. Western blot assays were used to detect the expression of factors associated with epithelial–mesenchymal transition. The interactions of LINC00467 with prostate cancer progression and M2 macrophage polarization were confirmed by RT-qPCR. The subcellular localization of LINC00467 was investigated via the fractionation of nuclear and cytoplasmic RNA. Bioinformatics data analysis was used to predict the correlation of LINC00467 expression with miR-494-3p expression. LINC00467/miR-494-3p/STAT3 interactions were identified by using a dual-luciferase reporter system. Finally, the influence of LINC00467 expression on PC progression was investigated with an in vivo nude mouse model of tumorigenesis.ResultsWe established that LINC00467 expression was upregulated in PC tissues and cells. Downregulated LINC00467 expression inhibited PC cell growth, cell cycle progression, migration, and invasion. Downregulated LINC00467 expression similarly inhibited PC cell migration via M2 macrophage polarization. Western blot analysis showed that LINC00467 could regulate the STAT3 pathway. We established that LINC00467 is mainly localized to the cytoplasm. Bioinformatics analysis and rescue experiments indicated that LINC00467 promotes PC progression via the miR-494-3p/STAT3 axis. Downregulated LINC00467 expression was also able to suppress PC tumor growth in vivo.ConclusionsOur study reveals that LINC00467 promotes prostate cancer progression via M2 macrophage polarization and the miR-494-3p/STAT3 axis.

Hsa-miR-149-5p Suppresses Prostate Carcinoma Malignancy by Suppressing RGS17.

BackgroundMicroRNAs (miRNAs) are key players in the progression of human cancers. While several miRNAs have been reported to regulate the development of tumors, the molecular mechanisms and roles of miR-149-5p in prostate carcinoma (PCa) remain unclear. Our aim was to investigate the interaction and functions of miR-149-5p and RGS17 in PCa.MethodsMicroarray analysis was performed to identify the key miRNA and gene involved in PCa progression. The expression levels of miRNA and mRNA in PCa tissues and cells were verified by qRT-PCR. MTT assay, BrdU proliferation assay and wound-healing assay were applied to assess the effect of miR-149-5p and RGS17 on PCa cells’ viability, proliferation, and migration ability. The association between RGS17 and miR-149-5p was identify using dual-luciferase reporter assay and Western blot assay.ResultsData analysis indicated the reduction of miR-149-5p expression in PCa tissues and cells. Experimental investigations also showed that this miRNA suppressed the viability, proliferation and migration ability of PCa cells. RGS17 was found to be the target of miR-149-5p, and the low expression of miR-149-5p upregulated RGS17 in PCa tissues and cells. The results of the cell-function assays showed that RGS17 acted as an oncogene in PCa even though its promotive effect could be reversed by miR-149-5p.ConclusionThis research confirmed that by targeting and inhibiting RGS17, miR-149-5p could suppress PCa development.

Abstract 6327: Artesunate reduces tumor growth and induces different kinds of cell death in docetaxel-resistant prostate carcinoma cells

Abstract Introduction: Prostate carcinoma (PCa) is the most common cancer in men. The therapeutic effect of approved compounds, such as docetaxel, is limited due to the development of therapy resistance, making new treatment options essential. Artesunate (ART), used in Traditional Chinese Medicine, has shown anti-tumor activity in several tumor types. However, little is known about the efficacy of ART on therapy-resistant PCa. Therefore, the impact of ART on docetaxel-resistant PCa cells was investigated. Material and Methods: Parental (=sensitive) and docetaxel-resistant PCa cell lines, PC3, DU145, and LNCaP, were exposed to ART [1-100 µM] for 24, 48, or 72 hours. Cells not exposed to ART served as controls. Tumor cell growth, proliferation, cell cycling, and the expression of cell cycle regulating proteins were assessed. Apoptotic, ferroptotic, and necrotic effects were also evaluated. Results: Exposure to ART significantly reduced tumor cell growth and proliferation of parental and docetaxel-resistant PCa cells in a time- and dose-dependent manner. Cell cycle arrest in the G0/G1 phase after 48h exposure to 37.5 µM ART was observed in parental LNCaP and in all three resistant cell lines. The observed changes in cell growth and cell cycle phases were accompanied by marked modulation of cell cycle regulating proteins. Significant apoptotic effects were observed in parental PC3 and both parental and resistant LNCaP, whereas ferroptosis was apparent in parental and resistant DU145 after exposure to ART. Necrotic events were not detectable in the PCa cells after ART exposure. Conclusion: ART induced anti-tumor effects, though differing according to the cell line, were apparent in not only parental but also in docetaxel-resistant PCa cells. Thus, adding ART to standard therapies might be a promising treatment strategy for patients with advanced prostate cancer. Further investigations are necessary to verify our findings. Citation Format: Vitus Braeunig, Patricia Schupp, Sascha Markowitsch, Olesya Vakhrusheva, Holger Erb, Thomas Efferth, Axel Haferkamp, Eva Juengel. Artesunate reduces tumor growth and induces different kinds of cell death in docetaxel-resistant prostate carcinoma cells [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 6327.

LncRNA Erbb4-IR is downregulated in prostate carcinoma and predicts prognosis.

Long non-coding (lnc) RNA Erbb4-IR has been associated with diabetic renal injury; however, its roles in other diseases remain unknown. Therefore, the present study investigated the involvement of Erbb4-IR in prostate carcinoma. Reverse transcription-quantitative PCR was used to analyze gene expression in tissue samples collected from patients with prostate carcinoma. Overexpression experiments via cell transfection were performed to determine the association between Erbb4-IR and microRNA (miR)-21. Furthermore, Cell Counting Kit-8 and cell apoptosis assays were performed to assess cell proliferation and apoptotic rate, respectively. The results revealed that Erbb4-IR was downregulated in prostate carcinoma tissues compared with adjacent non-cancerous tissues, and that low expression of Erbb4-IR in tumor tissues was closely associated with poor survival. Furthermore, miR-21 was upregulated in prostate carcinoma tissues compared with adjacent non-cancerous tissues and was inversely associated with Erbb4-IR expression in tumor tissues. In vitro cell experiments revealed that Erbb4-IR overexpression resulted in the downregulation of miR-21, while miR-21 overexpression did not significantly affect the expression of Erbb4-IR. Moreover, Erbb4-IR overexpression increased apoptosis and inhibited the proliferation of prostate carcinoma cells. miR-21 overexpression resulted in the opposite effect and attenuated the effects of Erbb4-IR overexpression. Therefore, the results of the present study suggested that lncRNA Erbb4-IR is downregulated in prostate carcinoma and may inhibit cancer development by downregulating miR-21.

LncRNA-SNHG16 Silencing Inhibits Prostate Carcinoma Cell Growth, Downregulate GLUT1 Expression and Reduce Glucose Uptake.

BackgroundlncRNA-SNHG16 was identified as an oncogene in many cancers, but its involvement in prostate carcinoma is unknown.Material and MethodExpression of lncRNA-SNHG16 and glucose transporter 1 (GLUT-1) in 52 prostate carcinoma tissues and 36 normal prostate tissues was analyzed by RT-qPCR. Transfections were performed to analyze gene interactions. Cell proliferation was analyzed by cell proliferation assay.ResultsOverexpression of lncRNA-SNHG16 effectively distinguished prostate carcinoma patients from normal ones. Expression levels of lncRNA-SNHG16 and GLUT-1 mRNA were significantly and positively correlated across prostate carcinoma tissues. In vitro cancer cell experiments revealed that lncRNA-SNHG16 siRNA silencing downregulated the expressions of GLUT-1 and reduced glucose uptake. lncRNA-SNHG16 siRNA silencing also significantly inhibited prostate carcinoma cell proliferation. However, lncRNA-SNHG16 siRNA silencing did not affect the normal prostate.ConclusionIn conclusion, lncRNA-SNHG16 might be a possible treatment target for prostate cancer.

Long non-coding RNA mortal obligate RNA transcript suppresses tumor cell proliferation in prostate carcinoma by inhibiting glucose uptake.

A previous study reported the decreased expression of long non-coding RNA mortal obligate RNA transcript (lncRNA MORT) in 16 types of cancer, while the functionality of lncRNA MORT in cancer biology remains unknown. Therefore, the present study was conducted to characterize the functionality of lncRNA MORT in prostate carcinoma, a common cancer type worldwide. lncRNA MORT expression level was downregulated in tumor tissues compared with that in the adjacent healthy tissues of patients with prostate carcinoma. Expression of lncRNA MORT in tumor tissues was influenced by tumor size, but not by tumor metastasis. Overexpression of lncRNA MORT inhibited glucose uptake and glucose transporter 1 (GLUT-1) expression in prostate carcinoma cell lines; GLUT-1 overexpression upregulated glucose uptake and attenuated the effects of lncRNA MORT overexpression on glucose uptake, but did not significantly affect the expression of lncRNA MORT. Overexpression of lncRNA MORT inhibited, while GLUT-1 overexpression promoted the proliferation of prostate carcinoma cells. In addition, GLUT-1 overexpression attenuated the effects of lncRNA MORT on cell proliferation. Therefore, lncRNA MORT may inhibit cancer cell proliferation in prostate carcinoma by preventing glucose uptake.

LncRNA GASL1 inhibits growth and promotes expression of apoptosis-associated proteins in prostate carcinoma cells through GLUT-1.

Growth-arrest-associated long non-coding (lnc)RNA 1 (GASL1) is as newly identified lncRNA that is associated with liver cancer. The present study aimed to investigate the role of GASL1 in prostate carcinoma (PC). Expression levels of GASL1 in prostate tissues and sera from patients with PC and from healthy subjects were detected by reverse transcription-quantitative polymerase chain reaction. Receiver operating characteristic and survival curve analyses were performed to evaluate the diagnostic and prognostic values of GASL1 for patients with PC. A GASL1 expression vector was transfected into PC cells prior to assessment of cell proliferation and expression of B cell lymphoma 2 (Bcl-2) and glucose transporter 1 (GLUT-1) by Cell Counting Kit-8 and western blotting, respectively. The results demonstrated that GASL1 was significantly downregulated in the tissue and serum of patients with PC compared to those of healthy subjects. In addition, GASL1 was used to distinguish patients with PC from healthy controls, and low expression levels of GASL1 were associated with short survival time. Expression levels of GASL1 were significantly associated with tumor size. GASL1 overexpression inhibited PC cell growth. Overexpression of GASL1 upregulated Bcl-2 expression and downregulated GLUT-1 expression. In conclusion, these data suggested that lncRNA GASL1 may inhibit PC cell proliferation by targeting GLUT-1.

MicroRNA‑122 downregulates Rho‑associated protein kinase 2 expression and inhibits the proliferation of prostate carcinoma cells.

MicroRNA‑122 (miR‑122) has been reported to be involved in the pathogenesis of several types of malignancies; however, its role in prostate carcinoma remains unknown. Thus, the current study aimed to investigate the functionality of miR‑122 in prostate carcinoma. Clinical data of 54patients with prostate carcinoma who were diagnosed and treated in Union Hospital (Wuhan, China) between January 2011 and January 2013 were retrospectively analyzed. The expression levels of miR‑122 and Rho‑associated protein kinase 2 (ROCK2) in prostate tumor and adjacent healthy tissues of patients, as well as in the serum of prostate carcinoma patients and healthy controls, were detected by reverse transcription‑quantitative polymerase chain reaction. Receiver operating characteristic curve and survival curve analyses were used to examine the diagnostic and prognostic values of serum miR‑122 for prostate carcinoma. In addition, miR‑122 mimic was transfected into prostate carcinoma cells, and the effects on cell proliferation and ROCK2 expression were explored by Cell Counting Kit‑8 and western blot assays, respectively. It was observed that miR‑122 was downregulated and ROCK2 was upregulated in tumor tissues as compared with their levels in adjacent healthy tissues. miR‑122 level in the serum was also markedly lower in prostate carcinoma patients in comparison with that in healthy controls. Furthermore, a low serum level of miR‑122 was found to effectively distinguish the prostate carcinoma patients from healthy controls and to be an indicator of poor survival. In prostate carcinoma cells, miR‑122 overexpression inhibited the proliferation and the expression of ROCK2. Taken together, miR‑122 may inhibit the proliferation of prostate carcinoma cells possibly by downregulating ROCK2 expression.

Long noncoding RNA POU3F3 promotes cancer cell proliferation in prostate carcinoma by upregulating rho-associated protein kinase 1.

Long noncoding RNAs (lncRNAs) POU3F3 is overexpressed in esophageal squamous-cell carcinomas, while its role in other human cancers is unclear. In this study we found that POU3F3 and rho-associated protein kinase 1 (ROCK1) were both increased in tumor tissues than in adjacent healthy tissues of patients with prostate carcinoma. Expression levels of POU3F3 increased with increase in the diameter of tumor but were not significantly affected by lymph node metastasis or distant metastasis. Expression levels of POU3F3 and ROCK1 were positive correlated in tumor tissues but not in adjacent healthy tissues. POU3F3 and ROCK1 overexpression promoted, while ROCK1 knockdown inhibited the proliferation of prostate carcinoma cells. ROCK1 knockdown reduced the enhancing effect of POU3F3 overexpression on cancer cell proliferation. POU3F3 overexpression led to ROCK1 overexpression in prostate carcinoma cells, while ROCK1 overexpression did not significantly affect POU3F3 expression. Therefore, lncRNA POU3F3 may promote cancer cell proliferation in prostate carcinoma by upregulating ROCK1.

Oxazoline derivatives of [17(20)E]-21-norpregnene – inhibitors of CYP17A1 activity and proliferation of prostate carcinoma cells

Nine new oxazolinyl derivatives of [17(20)E]-21-norpregnene, differing in the structure of steroid moiety, were investigated for their potency to inhibit the CYP17A1 catalytic activity, as well as growth and proliferation of LNCaP and PC-3 prostate carcinoma cell lines. The activity of one of the investigated compounds, 2´-{[(E)3β-hydroxyandrost-5-en-17-ylidene]methyl}-4´,5´-dihydro-1´,3´-oxazole (1), was found to be comparable with that of Abiraterone, a known inhibitor of CYP17A1 used for treatment of prostate cancer. A model of the interaction of oxazoline 1 with the active site of CYP17A1 was constructed by the molecular dynamics method. A correlation was found between the structure and the biological activity in the series of [17(20)E]-21-norpregnene oxazolinyl derivatives.

Stanniocalcin 1 promotes cell proliferation via cyclinE1/cyclin‑dependent kinase 2 in human prostate carcinoma.

Stanniocalcin 1 (STC1) is a glycoprotein hormone that is involved in calcium/phosphate homeostasis. Increasing evidence suggests that STC1 is involved in carcinogenesis; however, few studies have defined the mechanisms and functional roles of STC1 activity in prostate carcinogenesis. In the present study, MTT, flow cytometry and colony formation assays, and small interfering RNA (siRNA) and overexpression in multiple cell lines were used to investigate the function of STC1 in prostate carcinoma invivo and invivo. Knockdown of endogenous STC1 using a siRNA decreased the proliferation of DU145 and LNCaP2 cells. These results were consistent with the changes in the protein levels of cyclinE1 and cyclin‑dependent kinase2. By contrast, increased expression of STC1 in RWPE-1 cells led to increased cell proliferation, suggesting that STC1 promotes prostate carcinoma cell proliferation. In summary, the present study investigated the impact of STC1 on the proliferation and growth of prostate cancer in an effort to evaluate STC1 as a predictive biomarker and as a potential target for therapy.

MiR-96 promotes the growth of prostate carcinoma cells by suppressing MTSS1

Prostate carcinoma (PC) is one of the most common cancers for males. However, the molecular mechanisms of PC progression are still to be uncovered. MicroRNA (miRNA) has been shown to be associated with the initiation and progression of prostate cancer. Among the identified tumor-promoting miRNAs, miR-96 has been well established to contribute to PC by reducing FOXO1 expression. This study is aimed to study if miR-96 can promote the progression of PC through other pathways. Our data reinforced the finding that the level of miR-96 was higher in PC samples and cell lines than in non-cancerous tissues and normal prostate epithelial cells. In addition, serum miR-96 abundance was also found to be elevated in PC patients. Decreasing miR-96 expression was able to suppress the proliferation, clonogenicity, and invasion of PC cells. Overexpressing miR-96 led to increased proliferation and colony formation of normal prostate epithelial cells. miR-96 level was found to be inversely associated with the abundance of metastasis suppressor protein 1 (MTSS1) messenger RNA (mRNA), which has been proved to be a tumor suppressor for PC. Predictive analysis indicated that there was a potential miRNA response elements (MREs) located within 3'UTR of MTSS1 mRNA. The changes in miR-96 expression can affect the levels of MTSS1 both at mRNA and protein levels. miR-96 also suppressed the activity of luciferase reporter under the regulation of 3'UTR of MTSS1. Further studies showed that MTSS1 restoration accounted for the effect of miR-96 reduction on PC cells. The overexpression of a recombinant MTSS1 resistant against miRNA regulation was also demonstrated to abolish the transforming effect of miR-96 on prostate epithelial cells. Taken together, we found that miR-96 has a higher abundance in serum samples of PC patients than healthy controls, implying that it may be used as a prognostic marker. MTSS1 is a new authentic target of miR-96 in PC. The above findings suggested that targeting miR-96 may be a promising strategy for PC treatment.

Cisplatin modulates B-cell translocation gene 2 to attenuate cell proliferation of prostate carcinoma cells in both p53-dependent and p53-independent pathways.

Cisplatin is a widely used anti-cancer drug. The B-cell translocation gene 2 (BTG2) is involved in the cell cycle transition regulation. We evaluated the cisplatin effects on prostate cancer cell proliferation and the expressions of BTG2, p53, androgen receptor (AR) and prostate specific antigen (PSA) in prostate carcinoma, p53 wild-type LNCaP or p53-null PC-3, cells. Cisplatin treatments attenuated cell prostate cancer cell growth through inducing Go/G1 cell cycle arrest in lower concentration and apoptosis at higher dosage. Cisplatin treatments enhanced p53 and BTG2 expression, repressed AR and PSA expression, and blocked the activation of androgen on the PSA secretion in LNCaP cells. BTG2 knockdown in LNCaP cells attenuated cisplatin-mediated growth inhibition. Cisplatin enhanced BTG2 gene expression dependent on the DNA fragment located within -173 to -82 upstream of BTG2 translation initiation site in prostate cancer cells. Mutation of the p53 response element from GGGCAGAGCCC to GGGCACC or mutation of the NFκB response element from GGAAAGTCC to GGAAAGGAA by site-directed mutagenesis abolished the stimulation of cisplatin on the BTG2 promoter activity in LNCaP or PC-3 cells, respectively. Our results indicated that cisplatin attenuates prostate cancer cell proliferation partly mediated by upregulation of BTG2 through the p53-dependent pathway or p53-independent NFκB pathway.

Type 10 Soluble Adenylyl Cyclase Is Overexpressed in Prostate Carcinoma and Controls Proliferation of Prostate Cancer Cells

cAMP signaling plays an essential role in modulating the proliferation of different cell types, including cancer cells. Until now, the regulation of this pathway was restricted to the transmembrane class of adenylyl cyclases. In this study, significant overexpression of soluble adenylyl cyclase (sAC), an alternative source of cAMP, was found in human prostate carcinoma, and therefore, the contribution of this cyclase was investigated in the prostate carcinoma cell lines LNCaP and PC3. Suppression of sAC activity by treatment with the sAC-specific inhibitor KH7 or by sAC-specific knockdown mediated by siRNA or shRNA transfection prevented the proliferation of prostate carcinoma cells, led to lactate dehydrogenase release, and induced apoptosis. Cell cycle analysis revealed a significant rise in the G(2) phase population 12 h after sAC inhibition, which was accompanied by the down-regulation of cyclin B(1) and CDK1. sAC-dependent regulation of proliferation involves the EPAC/Rap1/B-Raf signaling pathway. In contrast, protein kinase A does not play a role. In conclusion, this study suggests a novel sAC-dependent signaling pathway that controls the proliferation of prostate carcinoma cells.

L-Mimosine blocks cell proliferation via upregulation of B-cell translocation gene 2 and N-myc downstream regulated gene 1 in prostate carcinoma cells

L-Mimosine, an iron chelator and a prolyl 4-hydroxylase inhibitor, blocks many cancer cells at the late G1 phase. B-cell translocation gene 2 (Btg2) regulates the G1/S transition phases of the cell cycle. N-myc downstream regulated gene 1 (Ndrg1) is a differentiation-inducing gene upregulated by hypoxia. We evaluated the molecular mechanisms of L-mimosine on cell cycle modulation in PC-3 and LNCaP prostate carcinoma cells. The effect of L-mimosine on cell proliferation of prostate carcinoma cells was determined by the [3H]thymidine incorporation and flow cytometry assays. L-Mimosine arrested the cell cycle at the G1 phase in PC-3 cells and at the S phase in LNCaP cells, thus attenuating cell proliferation. Immunoblot assays indicated that hypoxia and L-mimosine stabilized hypoxia-inducible factor-1α (HIF-1α) and induced Btg2 and Ndrg1 protein expression, but downregulated protein levels of cyclin A in both PC-3 and LNCaP cells. L-Mimosine treatment decreased cyclin D1 protein in PC-3 cells, but not in LNCaP cells. Dimethyloxalylglycine, a pan-prolyl hydroxylase inhibitor, also induced Btg2 and Ndrg1 protein expression in LNCaP cells. The transient gene expression assay revealed that L-mimosine treatment or cotransfection with HIF-1α expression vector enhanced the promoter activities of Btg2 and Ndrg1 genes. Knockdown of HIF-1α attenuated the increasing protein levels of both Btg2 and Ndrg1 by hypoxia or L-mimosine in LNCaP cells. Our results indicated that hypoxia and L-mimosine modulated Btg2 and Ndrg1 at the transcriptional level, which is dependent on HIF-1α. L-Mimosine enhanced expression of Btg2 and Ndrg1, which attenuated cell proliferation of the PC-3 and LNCaP prostate carcinoma cells.

The role of zinc transporter ZIP4 in prostate carcinoma

ObjectiveNormal prostate tissues have a unique function of accumulating high levels of zinc. This capability is lost during the early stage in the development of prostate malignancy. ZIP4 is an important zinc transporter. In this study, we explore the expression of ZIP4 in prostate carcinoma and invest the functional contributions of ZIP4 to cancer growth in vitro. MethodsZIP4 expression was detected in 14 prostate carcinoma and 20 BPH tissues by real-time RT-PCR and western blot. To invest the biological function of ZIP4 in prostate carcinoma cells, ZIP4 stable over-expression in cells was established in prostate carcinoma cell line DU145 (DU145-ZIP4) and ZIP4 short hairpin RNA(shRNA) expression in stable cells was also established in prostate carcinoma cell line 22RV1(22RV1-shRNA). The proliferation, migration, and invasion ability of the prostate carcinoma cells were detected. ResultsThe expression of ZIP4 mRNA and protein are significantly down-regulated in prostate carcinoma tissues compared with that in BPH tissues. However, we found that there was no correlation between the ZIP4 expression and the pathologic grade of prostate carcinoma. In in vitro studies, over-expression of ZIP4 not only inhibits the proliferation but also inhibits the invasive ability of prostate carcinoma cell line DU145-ZIP4. At the same time, we found silencing of ZIP4 was associated with increased cell proliferation and invasion ability in 22RV1-shRNA cell line. However, both DU145-ZIP4 and 22RV1-shRNA cells showed a significant reduction on cell migration ability compared with the control. ConclusionThe results indicate that ZIP4 expression is down-regulated in prostate carcinoma and it may serve as a promising biomarker for prostate carcinoma. ZIP4 has an inhibitory effect on prostate carcinoma cell proliferation and invasion. It suggests that ZIP4 may be a tumor suppressor gene and down-regulation of ZIP4 may be a critical early event in the development of prostate carcinoma.