NAT10 Promotes Prostate Cancer Growth and Metastasis by Acetylating mRNAs of HMGA1 and KRT8.

N4-acetylcytidine (ac4C) is essential for the development and migration of tumor cells. According to earlier research, N-acetyltransferase 10 (NAT10) can increase messenger RNAs (mRNAs) stability by catalyzing the synthesis of ac4C. However, little is known about NAT10 expression and its role in the acetylation modifications in prostate cancer (PCa). Thus, the biological function of NAT10 in PCa is investigated in this study. Compared to paraneoplastic tissues, the expression of NAT10 is significantly higher in PCa. The NAT10 expression is strongly correlated with the pathological grade, clinical stage, Gleason score, T-stage, and N-stage of PCa. NAT10 has the ability to advance the cell cycle and the epithelial-mesenchymal transition (EMT), both of which raise the malignancy of tumor cells. Mechanistically, NAT10 enhance the stability of high mobility group AT-hook 1 (HMGA1) by acetylating its mRNA, thereby promoting cell cycle progression to improve cell proliferation. In addition, NAT10 improve the stability of Keratin 8 (KRT8) by acetylating its mRNA, which promotes the progression of EMT to improve cell migration. This findings provide a potential prognostic or therapeutic target for PCa.

SETD4 inhibits prostate cancer development by promoting H3K27me3-mediated NUPR1 transcriptional repression and cell cycle arrest.

The suppressor of variegation enhancer of zeste-trithorax (SET) domain methyltransferases have been reported to function as key regulators in multiple tumor types by catalyzing histone lysine methylation. Nevertheless, our understanding on the role of these lysine methyltransferases, including SETD4, in prostate cancer (PCa) remains limited. Hence, the specific role of SETD4 in PCa was investigated in this study. The expression of SETD4 in PCa cells and tissue samples was downregulated in PCa cells and tissue specimens, and decreased SETD4 expression led to inferior clinicopathological characteristics in patients with PCa. knockdown of SETD4 facilitated the proliferation of PCa cells and accelerated cell cycle progression. Mechanistically, SETD4 repressed NUPR1 transcription by methylating H3K27 to generate H3K27me3, subsequently inactivated Akt pathway and impeded the tumorigenesis of PCa. Our results highlight that SETD4 prevents the development of PCa by catalyzing the methylation of H3K27 and suppressing NUPR1 transcription, subsequently inactivating the Akt signaling pathway. The findings suggest the potential application of SETD4 in PCa prognosis and therapeutics.

CircSMARCC1 facilitates tumor progression by disrupting the crosstalk between prostate cancer cells and tumor-associated macrophages via miR-1322/CCL20/CCR6 signaling.

BACKGROUND: Circular RNAs (circRNAs) mediate the infiltration of tumor-associated macrophages (TAMs) to facilitate carcinogenesis and development of various types of cancers. However, the role of circRNAs in regulating macrophages in prostate cancer (PCa) remains uncertain. METHODS: Differentially expressed circRNAs in PCa were identified by RNA sequencing. The expression of circSMARCC1 was recognized and evaluated using fluorescence in situ hybridization and quantitative real-time PCR. The oncogenic role of circSMARCC1 in PCa tumor proliferation and metastasis was investigated through a series of in vitro and in vivo assays. Finally, Western blot, biotin-labeled RNA pulldown, luciferase assay, rescue experiments, and co-culture experiments with TAMs were conducted to reveal the mechanistic role of circSMARCC1. RESULTS: CircSMARCC1 was dramatically up-regulated in PCa cells, plasma and tissues. Overexpression of circSMARCC1 promotes tumor proliferation and metastasis both in vitro and in vivo, whereas knockdown of circSMARCC1 exerts the opposite effects. Mechanistically, circSMARCC1 regulates the expression of CC-chemokine ligand 20 (CCL20) via sponging miR-1322 and activate PI3K-Akt signaling pathway involved in the proliferation and epithelial mesenchymal transformation. More importantly, high expression of circSMARCC1 was positively associated with colonization of CD68+/CD163+/CD206+ TAMs in tumor microenvironment. In addition, overexpression of circSMARCC1 facilitates the expression of CD163 in macrophages through the CCL20-CCR6 axis, induces TAMs infiltration and M2 polarization, thereby leading to PCa progression. CONCLUSIONS: CircSMARCC1 up-regulates the chemokine CCL20 secretion by sponging miR-1322, which is involved in the crosstalk between tumor cells and TAMs by targeting CCL20/CCR6 signaling to promote progression of PCa.

Identification of UAP1L1 as a critical factor for prostate cancer and underlying molecular mechanism in tumorigenicity.

BACKGROUND: Prostate cancer is the second most common cancer in men, and some new target genes are needed to predict the risk of prostate cancer progression and the treatment. METHODS: In this study, the effects of UAP1L1 (UAP1-like-1) on prostate cancer were investigated by detecting the proliferation, migration, invasion and apoptosis of prostate cancer cells in vitro using MTT, wound healing, Transwell and flow cytometry assay, and the tumor growth in vivo. The downstream genes and pathways of UAP1L1 were explored using Ingenuity Pathway Analysis (IPA), and screened by qRT-PCR and western blot. The effects of CDCA8 on prostate cancer cells were also verified in vitro, which was through detecting the change of proliferation, migration, invasion and apoptosis of prostate cancer cells after CDCA8 knockdown. RESULTS: The results indicated that UAP1L1 promoted the proliferation, migration and invasion of prostate cancer cells, which was inhibited by downregulating CDCA8. Furthermore, the promotion of CDCA8 knockdown on cell apoptosis was reduced when UAP1L1 was simultaneously overexpressed. CONCLUSIONS: In conclusion, the results in this study revealed that UAP1L1 promoted the progression of prostate cancer through the downstream gene CDCA8.

Hsa_circ_0003258 promotes prostate cancer metastasis by complexing with IGF2BP3 and sponging miR-653-5p.

BACKGROUND: More and more studies have shown that circular RNAs (circRNAs) play a critical regulatory role in many cancers. However, the potential molecular mechanism of circRNAs in prostate cancer (PCa) remains largely unknown. METHODS: Differentially expressed circRNAs were identified by RNA sequencing. The expression of hsa_circ_0003258 was evaluated using quantitative real-time PCR and RNA in situ hybridization. The impacts of hsa_circ_0003258 on the metastasis of PCa cells were investigated by a series of in vitro and in vivo assays. Lastly, the underlying mechanism of hsa_circ_0003258 was revealed by Western blot, biotin-labeled RNA pulldown, RNA immunoprecipitation, luciferase assays and rescue experiments. RESULTS: Increased expression of hsa_circ_0003258 was found in PCa tissues and was associated with advanced TNM stage and ISUP grade. Overexpression of hsa_circ_0003258 promoted PCa cell migration by inducing epithelial mesenchymal transformation (EMT) in vitro as well as tumor metastasis in vivo, while knockdown of hsa_circ_0003258 exerts the opposite effect. Mechanistically, hsa_circ_0003258 could elevate the expression of Rho GTPase activating protein 5 (ARHGAP5) via sponging miR-653-5p. In addition, hsa_circ_0003258 physically binds to insulin like growth factor 2 mRNA binding protein 3 (IGF2BP3) in the cytoplasm and enhanced HDAC4 mRNA stability, in which it activates ERK signalling pathway, then triggers EMT programming and finally accelerates the metastasis of PCa. CONCLUSIONS: Upregulation of hsa_circ_0003258 drives tumor progression through both hsa_circ_0003258/miR-653-5p/ARHGAP5 axis and hsa_circ_0003258/IGF2BP3 /HDAC4 axis. Hsa_circ_0003258 may act as a promising biomarker for metastasis of PCa and an attractive target for PCa intervention.

SMARCC1 Suppresses Tumor Progression by Inhibiting the PI3K/AKT Signaling Pathway in Prostate Cancer.

BACKGROUND: SWI/SNF-related, matrix-associated, actin-dependent regulator of chromatin subfamily C member 1 (SMARCC1) protein is a potential tumor suppressor in various cancers. However, its role in prostate cancer (PCa) remains controversial. The aim of this study was to determine the biological function of SMARCC1 in PCa and explore the underlying regulatory mechanisms. METHODS: The expression of SMARCC1 was validated in PCa tissues by immunohistochemistry. Meanwhile, function experiments were used to evaluate the regulatory role on cell proliferation and metastasis in PCa cells with SMARCC1 depletion both in vitro and in vivo. The expression levels of relevant proteins were detected by Western blotting. RESULTS: Our finding showed that SMARCC1 was significantly downregulated in prostate adenocarcinoma, with a higher Gleason score (GS) than that in low GS. The decreased expression of SMARCC1 was significantly correlated with a higher GS and poor prognosis. Additionally, we found that silencing of SMARCC1 dramatically accelerated cell proliferation by promoting cell cycle progression and enhancing cell migration by inducing epithelial mesenchymal transition (EMT). Furthermore, depletion of SMARCC1 facilitated PCa xenograft growth and lung metastasis in murine models. Mechanistically, the loss of SMARCC1 activated the PI3K/AKT pathway in PCa cells. CONCLUSION: SMARCC1 suppresses PCa cell proliferation and metastasis via the PI3K/AKT signaling pathway and is a novel therapeutic target.

The role of androgen therapy in prostate cancer: from testosterone replacement therapy to bipolar androgen therapy.

Testosterone replacement therapy (TRT) is the primary treatment for male testosterone deficiency. This therapy raises concerns over the risk of prostate cancer (PC), because testosterone has historically been considered the fuel for PC. We discuss the re-evaluation of the relationship between androgen and PC, and highlight the safety of TRT in the treatment of symptomatic men with testosterone deficiency who have low-risk disease after treatment for localized PC with surgery or radiation. Furthermore, we review the clinical application and potential mechanisms of bipolar androgen therapy (BAT) in the treatment of castration-resistant PC, emphasizing that much remains to be done before BAT can be broadly applied.

HMGB1 Promotes Prostate Cancer Development and Metastasis by Interacting with Brahma-Related Gene 1 and Activating the Akt Signaling Pathway.

Background and Aim: We have previously shown that high-mobility group box 1 (HMGB1) is an independent biomarker for shortened survival of prostate cancer (PCa) patients. However, the specific role of HMGB1 in tumor development and progression remains largely unknown. In this study, we investigated the molecular mechanisms of HMGB1 in PCa tumorigenesis. Methods: Gain-of-function and loss-of-function experiments were used to determine the biological functions of HMGB1 both in vitro and in vivo. Bioinformatic analysis, immunoprecipitation, and immunofluorescence assays were applied to discern and examine the relationship between HMGB1 and its potential targets. Specimens from 64 patients with PCa were analyzed for the expression of HMGB1 and its relationship with Brahma-related gene 1 (BRG1) was examined by immunohistochemistry. Results: The results demonstrated that ectopic expression of HMGB1 facilitated growth and metastasis of PCa by enhancing Akt signaling pathway and promoting epithelial-mesenchymal transition (EMT), while silencing of HMGB1 showed the opposite effects. Mechanistically, HMGB1 exerted these functions through its interaction with BRG1 which may augment BRG1 function and activate the Akt signaling pathway thereby promoting EMT. Importantly, both HMGB1 and BRG1 expression was markedly increased in human PCa tissues. Conclusions: Taken together, these findings indicate that upregulation of HMGB1 promotes PCa development via activation of Akt and accelerates metastasis through regulating BRG1-mediated EMT. HMGB1 could be used as a novel potential target for the treatment of PCa.

Synthesis and biological evaluation of arylpiperazine derivatives as potential anti-prostate cancer agents.

A novel scaffold of arylpiperazine derivatives was discovered as potent androgen receptor (AR) antagonist through rational drug designation based on our pre-work, leading to the discovery of a series of new antiproliferative compounds. Compounds 10, 16, 27, 29 and 31 exhibited relatively strong antagonistic potency against AR and exhibited potent AR binding affinities, while compounds 5, 6, 10, 14, 16, 19, 21, 27 and 31 exhibited strong cytotoxic activities against LNCaP cells (AR-rich) as well as also displayed the higher activities than finasteride toward PC-3 (AR-deficient) and DU145 (AR-deficient). Docking study suggested that the most potent antagonist 16 mainly bind to AR ligand binding pocket (LBP) site through hydrogen bonding interactions. The structure-activity relationship (SAR) of these designed arylpiperazine derivatives was rationally explored and discussed. These results indicated that the novel scaffold compounds demonstrated a step towards the development of novel and improved AR antagonists, and promising candidates for future development were identified.

Suppressed epithelial-mesenchymal transition and cancer stem cell properties mediate the anti-cancer effects of ethyl pyruvate via regulation of the AKT/nuclear factor-κB pathway in prostate cancer cells.

Castration-resistant prostate cancer (CRPC) is a leading cause of mortality among cases of prostate cancer (PCa). Current treatment options for CRPC are limited. Ethyl pyruvate (EP), a lipophilic derivative of pyruvic acid, has been reported to have antitumor activities. In the present study, the efficacy of EP against PCa was investigated using two human PCa cell lines and a mouse xenograft tumor model. PC3 and CWR22RV1 cells were treated with EP, and cytotoxicity was evaluated via Cell Counting Kit-8 and colony formation assays, while cell cycle distribution was assessed by flow cytometry. Changes in cell migration and invasion caused by EP treatment were also evaluated with Transwell and wound healing assays, and changes in the expression of intracellular signaling pathway components were detected by western blotting. EP treatment reduced cell viability, induced G1 arrest, and activated the intrinsic apoptosis pathway. Additionally, the in vivo experiments revealed that EP administration markedly inhibited tumor growth. EP also reversed epithelial-mesenchymal transition and suppressed cancer stem cell properties in part through negative regulation of AKT/nuclear factor-κB signaling. These results indicate that EP has anticancer activity in vitro and in vivo, and is therefore a promising therapeutic agent for the treatment of PCa.

Activation of necroptosis in a rat model of acute respiratory distress syndrome induced by oleic acid.

The present study was aimed to investigate the role of necroptosis in the pathogenesis of acute respiratory distress syndrome (ARDS). The rat model of ARDS was induced by intravenous injection of oleic acid (OA), and observed for 4 h. The lung injury was evaluated by arterial blood gas, lung wet-dry weight ratio (W/D) and histological analyses. Simultaneously, bronchoalveolar lavage fluid (BALF) was collected for total and differential cell analysis and total protein determination. Tumor necrosis factor alpha (TNF-α) level in BALF was determined with a rat TNF-α ELISA kit. Expressions of receptor interacting protein kinase 1 (RIPK1), RIPK3 and mixed lineage kinase domain-like protein (MLKL) in lung tissue were determined by Western blot and immunohistochemical staining. The interaction between RIPK1 and RIPK3 was explored by immunoprecipitation. The results showed that, compared with those in control group, total white blood cells count (WBC), polymorphonuclear percentage (PMN%), total protein concentration, TNF-α level in BALF, W/D, and the alveolar-arterial oxygen tension difference (P(A-a)O2) in OA group were significantly increased at 4 h after OA injection. Western blot and immunostaining further showed remarkably increased expressions of RIPK1, RIPK3 and MLKL in lung tissue from OA group. Additionally, immunoprecipitation results indicated an enforced interaction between RIPK1 and RIPK3 in OA group. Collectively, the TNF-α level in BALF and the RIPK1-RIPK3-MLKL signaling pathway in lung tissue were found to be upregulated and activated with the process of ARDS. These findings implicate that RIPK1/RIPK3-mediated necroptosis plays a possible role in the pathogenesis of ARDS, which may provide a new idea to develop novel drugs for the therapy of ARDS.

Necrostatin-1 protects against oleic acid-induced acute respiratory distress syndrome in rats.

Necroptosis is a recently discovered necrotic cell death which is regulated by receptor interacting protein kinase 1 (RIPK1) and RIPK3 under the stimulus of death signal and can be inhibited by necrostatin-1 (Nec-1) specifically. Therefore, the aim was to investigate the role of necroptosis in a rat model of acute respiratory distress syndrome (ARDS) induced by oleic acid (OA) and assess the effect of Nec-1 on lung injury in ARDS. Our results found that RIPK1, RIPK3 and mixed lineage kinase domain-like protein (MLKL) were abundantly expressed in rat lung tissues of OA-induced ARDS. Nec-1 pretreatment improved pulmonary function and attenuated lung edema dramatically in OA-induced ARDS rats. Furthermore, Nec-1 reduced RIPK1-RIPK3 interaction and down-regulated RIPK1-RIPK3-MLKL signal pathway, and inhibited inflammatory response by reducing neutrophil infiltration and protein leakage into lung tissue in OA-induced ARDS. Collectively, our study proves the intervention of necroptosis in OA-induced ARDS. Moreover, our findings imply that Nec-1 plays an important role in the treatment of ARDS via inhibiting necroptosis and inflammation.