Jia-hong Chen

MicroRNA-224 inhibits progression of human prostate cancer by downregulating TRIB1.

Our previous microarray data showed that microRNA‐224 (miR‐224) was downregulated in human prostate cancer (PCa) tissues compared with adjacent benign tissues. However, the underlying mechanisms by which miR‐224 is involved in PCa remain unclear. In this study, we identified TRIB1 as a target gene of miR‐224. Forced expression of miR‐224 suppressed PCa cell proliferation, invasion and migration, and promoted cell apoptosis by downregulating TRIB1. Moreover, the expression level of miR‐224 in PCa tissues was negatively correlated with that of TRIB1. miR‐224 downregulation was frequently found in PCa tissues with metastasis, higher PSA level and clinical stage, whereas TRIB1 upregulation was significantly associated with metastasis. Both miR‐224 downregulation and TRIB1 upregulation were significantly associated with poor biochemical recurrence‐free survival of patients with PCa. In conclusion, these findings reveal that the aberrant expression of miR‐224 and TRIB1 may promote PCa progression and have potentials to serve as novel biomarkers for PCa prognosis.

miR-195 Inhibits Tumor Progression by Targeting RPS6KB1 in Human Prostate Cancer

Purpose: To investigate the involvement of hsa-miRNA-195-5p (miR-195) in progression and prognosis of human prostate cancer. Experimental Design: qRT-PCR was performed to detect miR-195 expression in both prostate cancer cell lines and clinical tissue samples. Its clinical significance was statistically analyzed. The roles of miR-195 and its candidate target gene, ribosomal protein S6 kinase, 70 kDa, polypeptide 1 (RPS6KB1) in prostate cancer progression were confirmed on the basis of both in vitro and in vivo systems. Results: miR-195 downregulation in prostate cancer tissues was significantly associated with high Gleason score (P = 0.001), positive metastasis failure (P < 0.001), and biochemical recurrence (BCR, P < 0.001). Survival analysis identified miR-195 as an independent prognostic factor for BCR-free survival of prostate cancer patients (P = 0.022). Then, we confirmed the tumor suppressive role of miR-195 through prostate cancer cell invasion, migration, and apoptosis assays in vitro, along with tumor xenograft growth, angiogenesis, and invasion in vivo according to both gain-of-function and loss-of-function experiments. In addition, RPS6KB1 was identified as a novel direct target of miR-195 through proteomic expression profiling combined with bioinformatic target prediction and luciferase reporter assay. Moreover, the reexpression and knockdown of RPS6KB1 could respectively rescue and imitate the effects induced by miR-195. Importantly, RPS6KB1 expression was closely correlated with aggressive progression and poor prognosis in prostate cancer patients as opposed to miR-195. Furthermore, we identified MMP-9, VEGF, BAD, and E-cadherin as the downstream effectors of miR-195–RPS6KB1 axis. Conclusion: The newly identified miR-195–RPS6KB1 axis partially illustrates the molecular mechanism of prostate cancer progression and represents a novel potential therapeutic target for prostate cancer treatment. Clin Cancer Res; 21(21); 4922–34. ©2015 AACR.

MicroRNA‐23b downregulates peroxiredoxin III in human prostate cancer

To investigate the mechanism by which peroxiredoxin III (PRDX3) is altered in human prostate cancer (PCa), we used microRNA (miRNA) target prediction program and miRNA microarray to predict and identify miR‐23b as a candidate miRNA that targets PRDX3. We showed that miR‐23b suppresses PRDX3 protein expression in human DU145 cells under normal and hypoxic conditions. Additionally, the clinical significance of miR‐23b and PRDX3 expression in PCa patients was also confirmed. In conclusion, our data suggest that the effects of PRDX3 in PCa progression may be caused by the regulation function of miR‐23b, and consequently, miR‐23b may be involved in the response of PCa cells to hypoxia stress.

SOXs in Human Prostate Cancer: Implication as Progression and Prognosis Factors

BackgroundSOX genes play an important role in a number of developmental processes. Potential roles of SOXs have been demonstrated in various neoplastic tissues as tumor suppressors or promoters depending on tumor status and types. The aim of this study was to investigate the involvement of SOXs in the progression and prognosis of human prostate cancer (PCa).MethodsThe gene expression changes of SOXs in human PCa tissues compared with non-cancerous prostate tissues was detected using gene expression microarray, and confirmed by real-time quantitative reverse transcriptase-polymerase chain reaction (QRT-PCR) analysis and immunohositochemistry. The roles of these genes in castration resistance were investigated in LNCaP xenograft model of PCa.ResultsThe microarray analysis identified three genes (SOX7, SOX9 and SOX10) of SOX family that were significantly dis-regulated in common among four PCa specimens. Consistent with the results of the microarray, differential mRNA and protein levels of three selected genes were found in PCa tissues by QRT-PCR analysis and immunohistochemistry. Additionally, we found that the immunohistochemical staining scores of SOX7 in PCa tissues with higher serum PSA level (P = 0.02) and metastasis (P = 0.03) were significantly lower than those with lower serum PSA level and without metastasis; the increased SOX9 protein expression was frequently found in PCa tissues with higher Gleason score (P = 0.02) and higher clinical stage (P < 0.0001); the down-regulation of SOX10 tend to be found in PCa tissues with higher serum PSA levels (P = 0.03) and advanced pathological stage (P = 0.01). Moreover, both univariate and multivariate analyses showed that the down-regulation of SOX7 and the up-regulation of SOX9 were independent predictors of shorter biochemical recurrence-free survival. Furthermore, we discovered that SOX7 was significantly down-regulated and SOX9 was significantly up-regulated during the progression to castration resistance.ConclusionsOur data offer the convince evidence that the dis-regulation of SOX7, SOX9 and SOX10 may be associated with the aggressive progression of PCa. SOX7 and SOX9 may be potential markers for prognosis in PCa patients. Interestingly, the down-regulation of SOX7 and the up-regulation of SOX9 may be important mechanisms for castration-resistant progression of PCa.

Expression of Hedgehog Pathway Components is Associated with Bladder Cancer Progression and Clinical Outcome

Hedgehog (Hh) pathway has been implicated in the tumorigenesis of a large number of human tumors. But its effects on the progression and prognosis of bladder cancer remain poorly understood. The aim of this study was to investigate expression patterns of Hh pathway components in bladder cancer and to elucidate their prognostic values in this tumor. The expression of sonic hedgehog (Shh), its receptor Patched (Ptch1), and downstream transcription factor Gli1 in 118 specimens of bladder cancer and 30 specimens of adjacent normal bladder tissue was determined by immunohistochemistry. Statistical analyses were applied to test the relationship between the expression of these three proteins and clinicopathologic features and prognosis. Immunohistochemical staining results showed the localizations of Shh and Ptch1 proteins to be mainly located in the cytoplasm of bladder cancer cells, whereas Gli1 was mainly localized in the nuclear of tumor cells. Additionally, positive expression of Shh, Ptch1 and Gli1 proteins was correlated with pathological stage (P = 0.006, 0.006 and 0.008, respectively), venous invasion (P = 0.01, 0.01 and 0.012, respectively) and lymph node metastasis (P = 0.009, 0.01 and 0.013, respectively), but not with other factors including age, gender, tumor grade and recurrence of superficial cancer. Moreover, patients with positive expression of Shh, Ptch1 and Gli1 proteins respectively showed poorer disease-free (P = 0.002, 0.002 and 0.001, respectively) and overall survival (all P < 0.001) than those with negative expression of these three proteins. Univariate and multivariate analysis of prognostic factors in bladder cancer patients indicated that the expression patterns of Shh, Ptch1 and Gli1 proteins were independent unfavorable prognostic factors (all P < 0.001). This is the first report describing about the correlation between Hh pathway and the prognosis of bladder cancer. Expression of Shh, Ptch1 and Gli1 proteins was greater in bladder cancers than in the adjacent normal tissues. The examination of their expression is potentially valuable in prognostic evaluation of bladder cancer.

Extracellular matrix metalloproteinase inducer: a novel poor prognostic marker for human seminomas

ObjectiveExtracellular matrix metalloproteinase inducer (EMMPRIN) is a glycosylated member of the immunoglobulin superfamily whose function in human seminomas is unknown. We have recently determined that EMMPRIN possesses the ability to stimulate fibroblast and endothelial cell matrix metalloproteinase production, and that its expression was frequently up-regulated in several tumours of the urinary system. Thus, EMMPRIN expression might be associated with the progression of human seminomas. The aim of this study was to investigate whether the presence of EMMPRIN in seminoma tissues might help to predict the patients’ prognosis.MethodsParaffin-embedded tissues from 65 patients with seminomas and 20 normal testes were processed for immunohistochemical staining using a mouse monoclonal antibody generated against human EMMPRIN, as primary antibody, and a biotinylated goat-anti-mouse IgG, as secondary antibody. In addition, the correlation of EMMPRIN expression with clinicopathologic characteristics and patients’ prognosis was also analysed.ResultsEMMPRIN was detected in cancerous tissues of 53 patients with seminoma, but not normal testes. Thirty-five patients showed weakly to moderately positive and 18 patients intensely positive expression. Moreover, positive EMMPRIN staining correlated significantly with various clinicopathological factors (increased TNM stage and higher histological differentiation type) as well as decreased tumour-specific survival (log-rank, p=0.02). In particular, EMMPRIN expression was an independent prognosticator as shown by Cox regression analysis (p<0.001).ConclusionEMMPRIN expression in a primary tumour predicts an unfavourable prognosis in human seminoma, suggesting its crucial role in the progression of this tumour.

Overexpression of PDZ-binding kinase confers malignant phenotype in prostate cancer via the regulation of E2F1

Roles and mechanisms of cell cycle-specific transcription factor E2F1 on prostate cancer (PCa) have not been fully elucidated. To address this problem, we here identified PDZ-binding kinase (PBK) as a direct target for E2F1 through bioinformatics binding site prediction, combined with chromatin immunoprecipitation-PCR (ChIP-PCR), quantitative (Q)-PCR and Western blot analysis. Then, we observed that the knockdown of both E2F1 and PBK could suppress cell proliferation, invasion and migration of PCa cell lines in vitro. Based on Taylor dataset, we found that PBK upregulation occurred more frequently in PCa patients with the older age of patients (P=0.044), the higher Gleason score (P<0.001), the advanced clinical pathological stage (P=0.019), the presence of metastasis (P=0.008), the overall survival (P<0.001) and PSA failure (P=0.004). More interestingly, the survival analysis identified PBK as an independent factor for predicting the biochemical recurrence-free survival of PCa patients (P=0.041). Taken together, these findings offer the convincing evidence for the first time that the overexpression of PBK may lead to high malignant phenotype in PCa cells via the regulation of E2F1. PBK may function as a biomarker that can differentiate patients with biochemical recurrent and non-biochemical recurrent disease following radical prostatectomy, highlighting its potential as a therapeutic target.

Classical and Alternative Nuclear Factor-κB Pathways: A Comparison among Normal Prostate, Benign Prostate Hyperplasia and Prostate Cancer

Nuclear factor-κB (NF-κB) is controlled by the classical and alternative NF-κB pathways, the role of which in prostate cancer (PCa) is not clearly defined. To provide this missing translational link, we compared the classical and alternative NF-κB pathways in normal prostate, benign prostate hyperplasia (BPH) and PCa. Prostate specimens were divided into three groups: group A, PCa (n = 68); group B, BPH (n = 60); and group C, normal prostates (n = 15). The gene expression levels of NF-κB1 and NF-κB2 were determined by real-time quantitative RT-PCR. Additionally, we analyzed the expression and sub-cellular localization of phosphorylated P50 (p-P50) and phosphorylated P52 (p-P52) proteins by immunohistochemical staining. Furthermore, associations were made between NF-κB pathway proteins and patients’ prognosis. Compared with BPH and normal prostate tissues, the expression of NF-κB1 gene was differentially down-regulated by >1.5-fold, whereas NF-κB2 gene was differentially up-regulated by >2-fold in PCa tissues. The proportion of p-P50 positive patients in group A (26.5%) was significantly lower than in group B (88.3%, p = 0.005) and C (100%, p = 0.002). The proportion of p-P52 positive patients in group A (42.6%) was significantly higher than in group B (11.7%, p = 0.009) and C (6.7%, p = 0.008). Comparison of the survival curves in group A according to p-P52 expression showed a significant difference between positive and negative patients. The p-P52 positive patients showed worse prognosis (p = 0.019). Our findings suggest for the first time that the classical and alternative NF-κB pathways have an important role in PCa. p-P52 might be a predictor of poor prognosis for PCa.