Tumor Suppressor Role and Clinical Significance of the FEV Gene in Prostate Cancer.

Background: In our previous research, we developed a 32-gene risk index model that may be utilized as a robust prognostic method for predicting prostate cancer (PCa) recurrence after surgery. Among the 32 genes, the Fifth Ewing Variant (FEV) gene was one of the top downregulated genes in relapsed PCa. However, current understanding of the FEV gene and its involvement in PCa is limited. Methods: FEV mRNA expression was analyzed and correlated to clinical outcomes in PCa patients who underwent prostatectomy at the Massachusetts General Hospital. Specimens from tissue microarray (TMA) including 102 prostate cancer patients were analysis for the expression of FEV. Meanwhile, FEV expression profiles were also assessed in PCa cell lines and in BPH-1 prostate epithelial cells using western blotting and quantitative reverse transcription-PCR (qRT-PCR). Furthermore, we transfected LNCaP and PC-3 cells with either an empty vector or full-length FEV gene and performed in vitro cell functional assays. The part FEV plays in tumor xenograft growth was also assessed in vivo. Results: Of the 191 patients included in this study base on the DASL dataset, 77 (40.3%) and 24 (13.6%), respectively, developed prostate-specific antigen (PSA) relapse and metastasis postradical prostatectomy. Significant FEV downregulation was observed in PCa patients showing PSA failure and metastasis. The protein expression of FEV was significantly negatively correlated with the Gleason score and pathological stage in prostate cancer tissues. Similarly, FEV expression significantly decreased in all PCa cell lines relative to BPH-1 (all P < 0.05). Functional assays revealed that FEV expression markedly inhibited PCa cell growth, migration, and invasion, which in turn significantly repressed the growth of tumor xenografts in vivo. Conclusion: The results of this study suggest an association between downregulated FEV expression and PSA relapse in PCa patients. In addition, FEV may act as a tumor suppressor in PCa.

Downregulation of ARID4A and ARID4B promote tumor progression and directly regulated by microRNA-30d in patient with prostate cancer.

AT-rich interaction domain 4A (ARID4A) and AT-rich interaction domain 4B (ARID4B), which are both the AT-rich interaction domain (ARID) family, have been reported to be oncogene or tumor suppressor gene in various human malignances, but there is no involvement about their functions in prostate cancer (PCa). Our previous study has reported that microRNA-30d (miR-30d) expression can predicted poor clinical prognosis in PCa, however, the underlying mechanisms of miR-30d have not been fully described. The aim of our study is to investigate the expression relevance between miR-30d and ARID4A or ARID4B, and examine the clinical significance and biological function of ARID4A and AIRD4B in PCa. In this study, both ARID4A and ARID4B were identified as the target genes of miR-30d. In addition, the mRNA expression of miR-30d in PCa tissues were significantly negative correlated with ARID4A (Pearson correlation coefficient = -0.313, P = 0.001) and ARID4B (Pearson correlation coefficient = -0.349, P < 0.001), while there was a positive correlation between ARID4A and ARID4B (Pearson correlation coefficient = 0.865, P < 0.001). Moreover, both ARID4A and ARID4B were significantly downregulated in PCa tissues with high Gleason scores (P = 0.005, P = 0.033), PSA failure (P = 0.012, P = 0.05) and short biochemical recurrent-free survival (P = 0.033, P = 0.031). Furthermore, the knockout expression of ARID4A and ARID4B promoted PCa cell proliferation, migration and invasion in vitro. In conclusion, our results indicated that ARID4A and ARID4B may serve as tumor suppressor in PCa progression, suggesting that they might be the potential therapeutic targets in prostate cancer.

High expression of ASPM correlates with tumor progression and predicts poor outcome in patients with prostate cancer.

PURPOSE: Abnormal spindle microtubule assembly (ASPM) gene was known to be linked with poor clinical prognosis in various tumors. However, the clinical significance of ASPM in prostate cancer (PCa) has not yet been understood. The purpose of this study was to determine the association of ASPM with tumor progression and prognosis in PCa patients. METHODS: The expression of ASPM at protein level in human PCa and non-cancerous prostate tissue was detected by immunohistochemical analysis, which was further validated by using microarray-based dataset (NCBI GEO: GSE21032 and The Cancer Genome Atlas (TCGA) dataset) at mRNA level. Subsequently, the association of ASPM expression with the clinicopathological characteristics of patients with PCa was then statistically analyzed. RESULTS: Immunohistochemistry and dataset analyses revealed that ASPM expression was significantly increased in the PCa tissues with high Gleason score. Additionally, as showed by two datasets, ASPM expression was significantly high expressed in the PCa tissues when compared with the non-cancerous tissues, especially in advanced PCa pathological stage. The upregulation of ASPM mRNA expression in the PCa tissues significantly correlated with the presence of tumor metastasis, shorter overall survival and prostate-specific antigen (PSA) failure. Furthermore, both univariate and multivariate analyses showed that the upregulation of ASPM was a potential predictor of poor biochemical recurrence (BCR)-free survival. CONCLUSIONS: Our data suggest that ASPM may play an important role in the progression of PCa. More importantly, the increased expression of ASPM may potentially predict poor BCR-free survival in patients with PCa.