The long transcript of lncRNA TMPO-AS1 promotes bone metastases of prostate cancer by regulating the CSNK2A1/DDX3X complex in Wnt/ß-catenin signaling.

The second most common male cancer is prostate cancer (PCa), which has a high tendency for bone metastasis. Long non-coding RNAs, including TMPO-AS1, play a crucial role in PCa progression. However, TMPO-AS1's function in PCa bone metastasis (BM) and its underlying molecular mechanisms are unclear. Herein, we found that the long transcript of TMPO-AS1 (TMPO-AS1L) was upregulated in PCa tissues with bone metastasis, and overexpression of TMPO-AS1L correlated with advanced clinicopathological features and reduced BM-free survival in patients with PCa. Upregulated TMPO-AS1L promoted, whereas downregulated TMPO-AS1L inhibited, the PCa cell bone metastatic capacity in vitro and in vivo. Mechanistically, TMPO-AS1L was demonstrated to act as a scaffold, that strengthened the interaction of casein kinase 2 alpha 1 (CSNK2A1) and DEAD-box helicase 3 X-linked (DDX3X), and activated the Wnt/ß-catenin signaling pathway, thus promoting BM of PCa. Moreover, upregulation of TMPO-AS1L in PCa resulted from transcription elongation modulated by general transcription factor IIF subunit 2 (GTF2F2). Collectively, our study provides critical insights into the role of TMPO-AS1L in PCa BM via Wnt/ß-catenin signaling, identifying TMPO-AS1L as a candidate marker of PCa bone metastasis prognosis and therapeutic target.

BHLHE22 drives the immunosuppressive bone tumor microenvironment and associated bone metastasis in prostate cancer.

BACKGROUND: The molecular characteristics of prostate cancer (PCa) cells and the immunosuppressive bone tumor microenvironment (TME) contribute to the limitations of immune checkpoint therapy (ICT). Identifying subgroups of patients with PCa for ICT remains a challenge. Herein, we report that basic helix-loop-helix family member e22 (BHLHE22) is upregulated in bone metastatic PCa and drives an immunosuppressive bone TME. METHODS: In this study, the function of BHLHE22 in PCa bone metastases was clarified. We performed immunohistochemical (IHC) staining of primary and bone metastatic PCa samples, and assessed the ability to promote bone metastasis in vivo and in vitro. Then, the role of BHLHE22 in bone TME was determined by immunofluorescence (IF), flow cytometry, and bioinformatic analyses. RNA sequencing, cytokine array, western blotting, IF, IHC, and flow cytometry were used to identify the key mediators. Subsequently, the role of BHLHE22 in gene regulation was confirmed using luciferase reporter, chromatin immunoprecipitation assay, DNA pulldown, co-immunoprecipitation, and animal experiments. Xenograft bone metastasis mouse models were used to assess whether the strategy of immunosuppressive neutrophils and monocytes neutralization by targeting protein arginine methyltransferase 5 (PRMT5)/colony stimulating factor 2 (CSF2) could improve the efficacy of ICT. Animals were randomly assigned to treatment or control groups. Moreover, we performed IHC and correlation analyses to identify whether BHLHE22 could act as a potential biomarker for ICT combination therapies in bone metastatic PCa. RESULTS: Tumorous BHLHE22 mediates the high expression of CSF2, resulting in the infiltration of immunosuppressive neutrophils and monocytes and a prolonged immunocompromised T-cell status. Mechanistically, BHLHE22 binds to the CSF2 promoter and recruits PRMT5, forming a transcriptional complex. PRMT5 epigenetically activates CSF2 expression. In a tumor-bearing mouse model, ICT resistance of Bhlhe22+ tumors could be overcome by inhibition of Csf2 and Prmt5. CONCLUSIONS: These results reveal the immunosuppressive mechanism of tumorous BHLHE22 and provide a potential ICT combination therapy for patients with BHLHE22+ PCa.

CircITGB6 promotes ovarian cancer cisplatin resistance by resetting tumor-associated macrophage polarization toward the M2 phenotype.

BACKGROUND: Platinum resistance is a major challenge in the clinical treatment of advanced ovarian cancer (OC). Accumulating evidence shows that the tumor-promotive M2 macrophage is linked to the limiting chemotherapy efficacy of multiple malignancies including OC. Circular RNAs (circRNAs) are a novel class of non-coding RNAs which function as the critical regulator in biological process of cancer. However, their impact on macrophage polarization and chemoresistance of OC remain unclear. METHODS: Platinum-resistant circRNAs were screened using circRNA deep sequencing and validated using in situ hybridization in OC tissues with or without platinum resistance. The role of circITGB6 in inducing cisplatin (CDDP) resistance was evaluated by clone formation, immunofluorescence and annexin V assays in vitro, and by intraperitoneal tumor model in vivo. The mechanism underlying circITGB6-mediated tumor-associated macrophage (TAM) polarization into M2 phenotype was investigated using RNA pull-down, luciferase reporter, electrophoretic mobility shift, RNA binding protein immunoprecipitation (RIP), ELISA and immunofluorescence assays. RESULTS: We identified that a novel circRNA, circITGB6, robustly elevated in tumor tissues and serums from patients with OC with platinum resistance, was correlated with poor prognosis. circITGB6 overexpression promoted an M2 macrophage-dependent CDDP resistance in both vivo and vitro. Mechanistic research determined that circITGB6 directly interacted with IGF2BP2 and FGF9 mRNA to form a circITGB6/IGF2BP2/FGF9 RNA-protein ternary complex in the cytoplasm, thereby stabilizing FGF9 mRNA and inducing polarization of TAMs toward M2 phenotype. Importantly, blocking M2 macrophage polarization with an antisense oligonucleotide targeting circITGB6 markedly reversed the circITGB6-induced CDDP resistance of OC in vivo. CONCLUSIONS: This study reveals a novel mechanism for platinum resistance in OC and demonstrates that circITGB6 may serve as a potential prognostic marker and a therapeutic target for patients with OC.

m6 A modification of lncRNA PCAT6 promotes bone metastasis in prostate cancer through IGF2BP2-mediated IGF1R mRNA stabilization.

BACKGROUND: Bone metastasis is the leading cause of tumor-related death in prostate cancer (PCa) patients. Long noncoding RNAs (lncRNAs) have been well documented to be involved in the progression of multiple cancers. Nevertheless, the role of lncRNAs in PCa bone metastasis remains largely unclear. METHODS: The expression of prostate cancer-associated transcripts was analyzed in published datasets and further verified in clinical samples and cell lines by RT-qPCR and in situ hybridization assays. Colony formation assay, MTT assay, cell cycle analysis, EdU assay, Transwell migration and invasion assays, wound healing assay, and in vivo experiments were carried out to investigate the function of prostate cancer-associated transcript 6 (PCAT6) in bone metastasis and tumor growth of PCa. Bioinformatic analysis, RNA pull-down, and RIP assays were conducted to identify the proteins binding to PCAT6 and the potential targets of PCAT6. The therapeutic potential of targeting PCAT6 by antisense oligonucleotides (ASO) was further explored in vivo. RESULTS: PCAT6 was upregulated in PCa tissues with bone metastasis and increased PCAT6 expression predicted poor prognosis in PCa patients. Functional experiments found that PCAT6 knockdown significantly inhibited PCa cell invasion, migration, and proliferation in vitro, as well as bone metastasis and tumor growth in vivo. Mechanistically, METTL3-mediated m6 A modification contributed to PCAT6 upregulation in an IGF2BP2-dependent manner. Furthermore, PCAT6 upregulated IGF1R expression by enhancing IGF1R mRNA stability through the PCAT6/IGF2BP2/IGF1R RNA-protein three-dimensional complex. Importantly, PCAT6 inhibition by ASO in vivo showed therapeutic potential against bone metastasis in PCa. Finally, the clinical correlation of METTL3, IGF2BP2, IGF1R, and PCAT6 was further demonstrated in PCa tissues and cells. CONCLUSIONS: Our study uncovers a novel molecular mechanism by which the m6 A-induced PCAT6/IGF2BP2/IGF1R axis promotes PCa bone metastasis and tumor growth, suggesting that PCAT6 may serve as a promising prognostic marker and therapeutic target against bone-metastatic PCa.

Magnetic resonance imaging and dynamic X-ray's correlations with dynamic electrophysiological findings in cervical spondylotic myelopathy: a retrospective cohort study.

BACKGROUND: Dynamic somatosensory evoked potentials (DSSEP) can be used to disclose abnormalities of ascending sensory pathways at dynamic positions and diagnose cervical spondylotic myelopathy (CSM). However, radiographic tests including magnetic resonance imaging (MRI) and dynamic X-ray are used much more widely in the management of CSM. Our study aims to clarify the correlations between several radiographic parameters and the DSSEP results, and further determine their reliability with clinical data. METHODS: We retrospectively enrolled 38 CSM patients with surgical intervention. DSSEP tests were performed before surgery. Amplitude ratios of DSSEP N13 and N20 waves at extension and flexion were calculated and recorded as N13_E, N20_E, N13_F, N20_F, respectively. Baseline severity was evaluated with the modified Japanese Orthopedic Association (mJOA) score and the Nurick grades. Prognosis was evaluated based on the 2-year recovery rate. Sagittal diameter and transverse areas of the cord and canal were measured and the the compressive ratios at the compressed site (Compression_Ratio), central (Central_Ratio), and 1/4-lateral points (1/4-Lateral_Compression_Ratio), and spinal cord/Canal Area Ratio were calculated. The intramedullary T2 hyperintensity patterns (Ax-CCM types) were also collected from MRI axial images. Dynamic X-rays were used to test for segmental instability of the cervical spine. The correlations between radiologic findings, DSSEP data, and clinical assessments were investigated. RESULTS: We found that DSSEP N13_E and N13_F correlated with the Compression_Ratio, Central_Ratio, 1/4-Lateral_Compression_Ratio (Pearson, p < 0.05) and Ax-CCM types (ANOVA, p < 0.05) in MRI axial images and cervical segmental instability in dynamic X-ray (t-test, p < 0.05). Apart from the 1/4-Lateral_Compression_Ratio, these radiographic parameters above also correlated with the baseline clinical assessments (Spearman or ANOVA or t-test, p < 0.05) and postoperative recovery rate (Pearson or ANOVA or t-test, p < 0.05). CONCLUSIONS: We found that the preoperative Compression_Ratio, Central_Ratio and 1/4-Lateral_Compression_Ratio in MRI and cervical segmental instability in dynamic X-ray could reflect the dynamic neural dysfunction of the spinal cord. Different Ax-CCM types corresponded to different DSSEP results at extension and flexion, suggesting divergent pathophysiology. These radiographic parameters could help evaluate disease severity and predict postoperative prognosis.

PSMA-Targeting Reduction-Cleavable Hyperbranched Polyamide-Amine Gene Delivery System to Treat the Bone Metastases of Prostate Cancer.

OBJECTIVE: This study aimed to develop aptamer-anchored hyperbranched poly(amido amine) (HPAA) for the systemic delivery of miRNA-133a-3p and to evaluate its therapeutic potential against bone metastasis of prostate cancer in vivo and in vitro. METHODS: A glutathione (GSH)-responsive cationic HPAA was prepared by the Michael addition reaction. Furthermore, HPAA-PEG was produced by PEGylation, and then the aptamer targeted to prostate-specific membrane antigen (PSMA) was conjugated to the HPAA-PEG. The obtained HPAA-PEG-APT could form nanocomplexes with miRNA-133a-3p through electrostatic adsorption. RESULTS: The results of immunocytochemistry indicated that the complexes could target PSMA-expressing LNCaP cells. The ability of HPAA-PEG-APT to facilitate the delivery of miRNA-133a-3p into LNCaP cells was proven, and HPAA-PEG-APT/miRNA-133a-3p demonstrated enhanced antitumor activity, lower cytotoxicity and better biocompatibility in vitro. Moreover, in a mouse tibial injection tumor model, the intravenous injection of the HPAA-PEG-APT/miRNA-133a-3p complex significantly inhibited cancer growth and extended the survival time. CONCLUSION: This study provided an aptamer-anchored HPAA-loaded gene system to deliver miRNA-133a-3p for better therapeutic efficacy of bone metastasis of prostate cancer.

TRIB3 confers radiotherapy resistance in esophageal squamous cell carcinoma by stabilizing TAZ.

Radioresistance becomes the major obstacle to reduce tumor recurrence and improve prognosis in the treatment of esophageal squamous cell carcinoma (ESCC). Thus new strategies for radioresistant ESCC are urgently needed. Herein, we reported that tribbles pseudokinase 3 (TRIB3) serves as a key regulator of radioresistance in ESCC. TRIB3 is overexpressed in ESCC tissues and cell lines. High expression of TRIB3 significantly correlates with poor radiotherapy response and prognosis in ESCC patients. Upregulation of TRIB3 in ESCC cells conferred radioresistance in vitro and in vivo by interacting with TAZ thus impeding ß-TrCP-mediated TAZ ubiquitination and degradation. Conversely, silencing TRIB3 sensitized ESCC cells to ionizing radiation. More importantly, TRIB3 was significantly correlated with TAZ activation in ESCC biopsies, and patients with high expression of both TRIB3 and TAZ suffered the worst radiotherapy response and survival. Our study uncovers the critical mechanism of ESCC resistance to radiotherapy, and provides a new pharmacological opportunity for developing a mechanism-based strategy to eliminate radioresistant ESCC in clinical practice.

SMAD3/SP1 complex-mediated constitutive active loop between lncRNA PCAT7 and TGF-ß signaling promotes prostate cancer bone metastasis.

Bone metastasis is associated with cancer-related death in patients with prostate cancer (PCa). Long noncoding RNAs (lncRNAs) play critical roles in tumor progression of PCa. Nevertheless, the biological function of lncRNAs in PCa bone metastasis remains unclear. PCAT7 was identified as a bone metastasis-related lncRNA via analyzing TCGA dataset. Meanwhile, PCAT7 was found to be elevated in primary PCa tissues with bone metastasis and associated with bone metastasis status and poor prognosis of patients with PCa. Functionally, our results reveal that PCAT7 overexpression promotes PCa bone metastasis in vivo, as well as migration, invasion, and EMT of PCa cells in vitro; on the contrary, PCAT7 knockdown has an inverse effect. Mechanistically, PCAT7 activates TGF-ß/SMAD signaling by upregulating TGFBR1 expression via sponging miR-324-5p. In turn, TGF-ß signaling forms a positive feedback loop with PCAT7 via SMAD3/SP1 complex-induced PCAT7 upregulation. Finally, the clinical positive correlation between PCAT7 and TGFBR1 and TGF-ß signaling activity, and the negative association with miR-324-5p are further demonstrated in PCa tissues and clinical primary PCa cells. This study reveals a novel mechanism that is responsible for the constitutive activation of TGF-ß signaling in PCa bone metastasis, implying that PCAT7 can act as a potential therapeutic target against bone metastasis of PCa via disrupting the constitutive active loop between PCAT7 and TGF-ß signaling.

Copy number gain of ZEB1 mediates a double-negative feedback loop with miR-33a-5p that regulates EMT and bone metastasis of prostate cancer dependent on TGF-ß signaling.

Background: The reciprocal repressive loop between ZEB1 and miRNAs has been extensively reported to play an important role in tumor progression and metastasis of various human tumor types. The aim of this study was to elucidate the role and the underlying mechanism of the double-negative feedback loop between ZEB1and miR-33a-5p in bone metastasis of prostate cancer (PCa). Methods: miR-33a-5p expression was examined in 40 bone metastatic and 165 non-bone metastatic PCa tissues by real-time PCR. Statistical analysis was performed to evaluate the clinical correlation between miR-33a-5p expression and clinicopathological characteristics, and overall and bone metastasis-free survival in PCa patients. The biological roles of miR-33a-5p in bone metastasis of PCa were investigated both by EMT and the Transwell assay in vitro, and by a mouse model of left cardiac ventricle inoculation in vivo. siRNA library, real-time PCR and chromatin immunoprecipitation (ChIP) were used to identify the underlying mechanism responsible for the decreased expression of miR-33a-5p in PCa. Bioinformatics analysis, Western blotting and luciferase reporter analysis were employed to examine the relationship between miR-33a-5p and its potential targets. Clinical correlation of miR-33a-5p with its targets was examined in human PCa tissues and primary PCa cells. Results: miR-33a-5p expression was downregulated in PCa tissues with bone metastasis and bone-derived cells, and low expression of miR-33a-5p strongly and positively correlated with advanced clinicopathological characteristics, and shorter overall and bone metastasis-free survival in PCa patients. Upregulating miR-33a-5p inhibited, while silencing miR-33a-5p promoted EMT, invasion and migration of PCa cells. Importantly, upregulating miR-33a-5p significantly repressed bone metastasis of PC-3 cells in vivo. Our results further revealed that recurrent ZEB1 upregulation induced by copy number gains transcriptionally inhibited miR-33a-5p expression, contributing to the reduced expression of miR-33a-5p in bone metastatic PCa tissues. In turn, miR-33a-5p formed a double negative feedback loop with ZEB1 in target-independent manner, which was dependent on TGF-ß signaling. Finally, the clinical negative correlations of miR-33a-5p with ZEB1 expression and TGF-ß signaling activity were demonstrated in PCa tissues and primary PCa cells. Conclusion: Our findings elucidated that copy number gains of ZEB1-triggered a TGF-ß signaling-dependent miR-33a-5p-mediated negative feedback loop was highly relevant to the bone metastasis of PCa.

MAZ promotes prostate cancer bone metastasis through transcriptionally activating the KRas-dependent RalGEFs pathway.

BACKGROUND: Clinically, prostate cancer (PCa) exhibits a high avidity to metastasize to bone. Myc-associated zinc-finger protein (MAZ) is a well-documented oncogene involved in the progression and metastasis of multiple cancer types, even in PCa. However, the clinical significance and biological roles of MAZ in bone metastasis of PCa remain unclear. METHODS: MAZ expression was examined in PCa tissues with bone metastasis, PCa tissues without bone metastasis and metastatic bone tissues by real-time PCR and immunohistochemistry (IHC), respectively. Statistical analysis was performed to evaluate the clinical correlation between MAZ expression and clinicopathological features and bone metastasis-free survival in PCa patients. Biological roles of MAZ in bone metastasis of PCa were investigated both in vitro by transwell assay, and in vivo by a mouse model of left cardiac ventricle inoculation. The bioinformatics analysis, western blot, pull-down assays, chromatin immunoprecipitation (ChIP) and luciferase reporter assays were applied to demonstrate and examine the relationship between MAZ and its potential downstream signalling pathway. TaqMan copy number assay was performed to identify the underlying mechanism responsible for MAZ overexpression in PCa tissues. RESULTS: MAZ expression is elevated in PCa tissues with bone metastasis compared with that in PCa tissues without bone metastasis, and is further increased in metastatic bone tissues. High expression of MAZ positively correlates with poor overall and bone metastasis-free survival in PCa patients. Upregulating MAZ elevates, while silencing MAZ represses the invasion and migration abilities of PCa cells in vitro and bone metastasis ability in vivo. Our results further reveal that MAZ promotes bone metastasis of PCa dependent on KRas signalling, although MAZ transcriptionally upregulates KRas and HRas expression, where the Ral guanine nucleotide exchange factor (RalGEF) signaling is responsible for the different roles of KRas and HRas in mediating the pro-bone metastasis of MAZ in PCa. Finally, our results indicate that recurrent gains contribute to MAZ overexpression in a small portion of PCa tissues. CONCLUSION: These results indicate that the MAZ/Kras/ RalGEF signalling axis plays a crucial role in promoting PCa cell bone metastasis, suggesting a potential therapeutic utility of MAZ in bone metastasis of PCa.

Nuclear orphan receptor NR2F6 confers cisplatin resistance in epithelial ovarian cancer cells by activating the Notch3 signaling pathway.

The primary challenge facing treatment of epithelial ovarian cancer (EOC) is the high frequency of chemoresistance, which severely impairs the quality of life and survival of patients with EOC. Our study aims to investigate the mechanisms by which upregulation of NR2F6 induces chemoresistance in EOC. The biological roles of NR2F6 in EOC chemoresistance were explored in vitro by Sphere, MTT and AnnexinV/PI assay, and in vivo using an ovarian cancer orthotopic transplantation model. Bioinformatics analysis, luciferase assay, CHIP and IP assays were performed to identify the mechanisms by which NR2F6 promotes chemoresistance in EOC. The expression of NR2F6 was significantly upregulated in chemoresistant EOC tissue, and NR2F6 expression was correlated with poorer overall survival. Moreover, overexpression of NR2F6 promotes the EOC cancer stem cell phenotype; conversely, knockdown of NR2F6 represses the EOC cancer stem cell phenotype and sensitizes EOC to cisplatin in vitro and in vivo. Our results further demonstrate that NR2F6 sustains activated Notch3 signaling, resulting in chemoresistance in EOC cells. Notably, NR2F6 acts as an informative biomarker to identify the population of EOC patients who are likely to experience a favorable objective response to gamma-secretase inhibitors (GSI), which inhibit Notch signaling. Therefore, concurrent inhibition of NR2F6 and treatment with GSI and cisplatin-based chemotherapy may be a novel therapeutic approach for NR2F6-overexpressing EOC. In summary, we have, for the first time, identified an important role for NR2F6 in EOC cisplatin resistance. Our study suggests that GSI may serve as a potential targeted treatment for patients with NR2F6-overexpressing EOC.

Wnt5a induces and maintains prostate cancer cells dormancy in bone.

In a substantial fraction of prostate cancer (PCa) patients, bone metastasis appears after years or even decades of latency. Canonical Wnt/ß-catenin signaling has been proposed to be implicated in dormancy of cancer cells. However, how these tumor cells are kept dormant and recur under control of Wnt/ß-catenin signaling derived from bone microenvironment remains unknown. Here, we report that Wnt5a from osteoblastic niche induces dormancy of PCa cells in a reversible manner in vitro and in vivo via inducing Siah E3 Ubiquitin Protein Ligase 2 (SIAH2) expression, which represses Wnt/ß-catenin signaling. Furthermore, this effect of Wnt5a-induced dormancy of PCa cells depends on receptor tyrosine kinase-like orphan receptor 2 (ROR2), and a negative correlation of ROR2 expression with bone metastasis-free survival is observed in PCa patients. Therefore, these results demonstrate that Wnt5a/ROR2/SIAH2 signaling axis plays a crucial role in inducing and maintaining PCa cells dormancy in bone, suggesting a potential therapeutic utility of Wnt5a via inducing dormancy of PCa cells in bone.

Transcriptional downregulation of miR-133b by REST promotes prostate cancer metastasis to bone via activating TGF-ß signaling.

High avidity of bone metastasis is an important characteristic in prostate cancer (PCa). Downexpression of miR-133b has been reported to be implicated in the development, progression and recurrence in PCa. However, clinical significance and biological roles of miR-133b in bone metastasis of PCa remain unclear. Here we report that miR-133b is downregulated in PCa tissues and further decreased in bone metastatic PCa tissues. Downexpression of miR-133b positively correlates with advanced clinicopathological characteristics and shorter bone metastasis-free survival in PCa patients. Upregulating miR-133b inhibits invasion, migration in vitro and bone metastasis in vivo in PCa cells. Mechanistically, we find that miR-133b suppresses activity of TGF-ß signaling via directly targeting TGF-ß receptor I and II, which further inhibits bone metastasis of PCa cells. Our results further reveal that overexpression of REST contributes to miR-133b downexpression via transcriptional repression in PCa tissues. Importantly, silencing miR-133b enhances invasion and migration abilities in vitro and bone metastasis ability in vivo in REST-silenced PCa cells. The clinical correlation of miR-133b with TGFBRI, TGFBRII, REST and TGF-ß signaling activity is verified in PCa tissues. Therefore, our results uncover a novel mechanism of miR-133b downexpression that REST transcriptionally inhibits miR-133b expression in PCa cells, and meanwhile support the notion that administration of miR-133b may serve as a rational regimen in the treatment of PCa bone metastasis.

The TGF-ß signalling negative regulator PICK1 represses prostate cancer metastasis to bone.

Backgroud:Constitutive activation of TGF-ß signalling is a well-recognised mechanism in bone metastasis of prostate cancer (PCa). Protein Interacting with PRKCA 1 (PICK1) is a critical negative regulator of the TGF-ß pathway. However, the clinical significance and biological role of PICK1 in PCa bone metastasis remain obscure. METHODS: PICK1 expression is evaluated by immunohistochemistry (IHC) in 198 PCa patients. Statistical analysis is performed to explore correlation between PICK1 expression and clinicopathological features in PCa patients. The biological role of PICK1 is examined in PC-3 and C4-2B cells in vitro and a mouse intracardial model in vivo. RESULTS: PICK1 expression is decreased in PCa tissues with bone metastasis and bone-derived cells and downregulation of PICK1 positively correlates with serum PSA level, Gleason grade and bone metastasis status in PCa patients. Overexpression of PICK1 suppresses PCa cell invasion and migration in vitro and bone metastasis in vivo. Our results further indicate downregulation of PICK1 is caused by miR-210-3p overexpression in PCa tissues with bone metastasis. Clinical negative correlation of PICK1 with miR-210-3p is confirmed in PCa tissues. CONCLUSIONS: Our findings uncover a novel functionally and clinically relevant epigenetic regulatory mechanism for constitutive activation of TGF-ß signalling in bone metastasis of PCa.

Oncogenic miR-210-3p promotes prostate cancer cell EMT and bone metastasis via NF-κB signaling pathway.

BACKGROUND: The primary issue arising from prostate cancer (PCa) is its high prevalence to metastasize to bone, which severely affects the quality of life and survival time of PCa patients. miR-210-3p is a well-documented oncogenic miRNA implicated in various aspects of cancer development, progression and metastasis. However, the clinical significance and biological roles of miR-210-3p in PCa bone metastasis remain obscure. METHODS: miR-210-3p expression was evaluated by real-time PCR in 68 bone metastatic and 81 non-bone metastatic PCa tissues. The biological roles of miR-210-3p in the bone metastasis of PCa were investigated both in vitro by EMT and Transwell assays, and in vivo using a mouse model of left cardiac ventricle inoculation. Bioinformatics analysis, real-time PCR, western blot and luciferase reporter analysis were applied to discern and examine the relationship between miR-210-3p and its potential targets. RT-PCR was performed to identify the underlying mechanism of miR-210-3p overexpression in bone metastasis of PCa. Clinical correlation of miR-210-3p with its targets was examined in human PCa and metastatic bone tissues. RESULTS: miR-210-3p expression is elevated in bone metastatic PCa tissues compared with non-bone metastatic PCa tissues. Overexpression of miR-210-3p positively correlates with serum PSA levels, Gleason grade and bone metastasis status in PCa patients. Upregulating miR-210-3p enhances, while silencing miR-210-3p represses the EMT, invasion and migration of PCa cells in vitro. Importantly, silencing miR-210-3p significantly inhibits bone metastasis of PC-3 cells in vivo. Our results further demonstrate that miR-210-3p maintains the sustained activation of NF-κB signaling via targeting negative regulators of NF-κB signaling (TNF-α Induced Protein 3 Interacting Protein 1) TNIP1 and (Suppressor Of Cytokine Signaling 1) SOCS1, resulting in EMT, invasion, migration and bone metastasis of PCa cells. Moreover, our results further indicate that recurrent gains (amplification) contribute to miR-210-3p overexpression in a small number of PCa patients. The clinical correlation of miR-210-3p with SOCS1, TNIP1 and NF-κB signaling activity is verified in PCa tissues. CONCLUSION: Our findings unravel a novel mechanism for constitutive activation of NF-κB signaling pathway in the bone metastasis of PCa, supporting a functional and clinical significance of epigenetic events in bone metastasis of PCa.

Hepcidin promotes osteogenic differentiation through the bone morphogenetic protein 2/small mothers against decapentaplegic and mitogen-activated protein kinase/P38 signaling pathways in mesenchymal stem cells.

The ability of mesenchymal stem cells (MSCs) to differentiate into osteogenic lineages requires management for their future use in treating bone destruction and osteoporosis. Hepcidin is closely associated with bone metabolism, however, it remains to be elucidated whether hepcidin affects osteogenic differentiation in MSCs. The present study demonstrated that hepcidin enhanced osteoblastic differentiation and mineralization, which was manifested by an upregulation in the differentiation markers alkaline phosphatase and osteogenic genes. Furthermore, the expression levels of bone morphogenetic proteins and small mothers against decapentaplegic homologs were concomitantly increased following hepcidin treatment. In addition, the p38 mitogen-activated protein kinase may be an upstream kinase for osteoblastic differentiation. Thus, hepcidin may be important in the osteogenic differentiation of MSCs and may be considered as a target in the development of therapies for pathological bone loss.

Glatiramer acetate inhibits degradation of collagen II by suppressing the activity of interferon regulatory factor-1.

Pro-inflammatory cytokines such as tumor necrosis factor-alpha (TNF-α) is considered to be the major one contributing to the process of development of osteoarthritis (OA).Interferon regulatory factor 1 (IRF-1) is an important transcriptional factor accounting for inflammation response induced by TNF-α. The physiological function of IRF-1 in OA is still unknown. In this study, we reported that the expression levels of IRF-1 in OA chondrocytes were significantly higher compared to those in normal chondrocytes, which was reversed by treatment with Glatiramer acetate (GA), a licensed clinical drug for treating patients suffering from multiple sclerosis (MS). We also found that GA is able to attenuate the upregulation of IRF-1 induced by TNF-α. Matrix metalloproteinase13 (MMP-13) is one of the downstream target genes of IRF-1, which can induce the degradation of collagen II. Importantly, our results indicated that GA suppressed the expression of MMP-13 as well as the degradation of collagen II. In addition, GA also suppressed TNF-α-induced production of NO and expression of iNOS. Finally, we found that the inhibition of STAT1 activation played a critical role in the inhibitory effects of GA on the induction of IRF-1 and MMP-13. These data suggest that GA might have a potential effect in therapeutic OA.

c-Jun transactivates Puma gene expression to promote osteoarthritis.

Osteoarthritis (OA) is a chronic degenerative joint disorder in which genetic, hormonal, mechanical and ageing factors affect its progression. Current studies are focusing on chondrocytes as a key mediator of OA at a cellular level. however, the mechanism underlying chondrocyte apoptosis remains unclear. PUMA is a pro-apoptotic member of the BH3-only subgroup of the Bcl-2 family and is involved in a large number of physiological and pathological processes. In the present study, we examined whether PUMA has a role in IL-1ß-induced apoptosis and whether the c-Jun N-terminal kinase (JNK)/c-Jun pathway mediates the induction of PUMA, thus contributing to chondrocyte apoptosis. The results demonstrated an increase in PUMA protein and mRNA levels in cultured mouse chondrocytes following 4 h of IL-1ß treatment. Furthermore, this upregulation of PUMA was critical for chondrocyte apoptosis as knockdown of PUMA using PUMA-specific siRNA significantly reduced apoptosis in cultured cells. Upon pharmacological inhibition of the JNK/c-Jun pathway with CE11004 or SP600125, the expression of PUMA was notably suppressed with a concomitant decrease in apoptosis observed in IL-1ß-treated chondrocytes. Also, immunohistochemical studies revealed that the PUMA and c-Jun proteins were upregulated in chondrocytes from the articular cartilage of OA patients. Together, these data suggest a role for PUMA and the JNK/c-Jun pathway in the regulation of chondrocyte apoptosis during OA.