High RBM3 expression in prostate cancer independently predicts a reduced risk of biochemical recurrence and disease progression

<p>Abstract</p> <p>Background</p> <p>High expression of the RNA-binding protein RBM3 has previously been found to be associated with good prognosis in breast cancer, ovarian cancer, malignant melanoma and colorectal cancer. The aim of this study was to examine the prognostic impact of immunohistochemical RBM3 expression in prostate cancer.</p> <p>Findings</p> <p>Immunohistochemical RBM3 expression was examined in a tissue microarray with malignant and benign prostatic specimens from 88 patients treated with radical prostatectomy for localized disease. While rarely expressed in benign prostate gland epithelium, RBM3 was found to be up-regulated in prostate intraepithelial neoplasia and present in various fractions and intensities in invasive prostate cancer. High nuclear RBM3 expression was significantly associated with a prolonged time to biochemical recurrence (BCR) (HR 0.56, 95% CI: 0.34-0.93, <it>p </it>= 0.024) and clinical progression (HR 0.09, 95% CI: 0.01-0.71, <it>p = </it>0.021). These associations remained significant in multivariate analysis, adjusted for preoperative PSA level in blood, pathological Gleason score and presence or absence of extracapsular extension, seminal vesicle invasion and positive surgical margin (HR 0.41, 95% CI: 0.19-0.89, <it>p </it>= 0.024 for BCR and HR 0.06, 95% CI: 0.01-0.50, <it>p = </it>0.009 for clinical progression).</p> <p>Conclusion</p> <p>Our results demonstrate that high nuclear expression of RBM3 in prostate cancer is associated with a prolonged time to disease progression and, thus, a potential biomarker of favourable prognosis. The value of RBM3 for prognostication, treatment stratification and follow-up of prostate cancer patients should be further validated in larger studies.</p

miR-34c is downregulated in prostate cancer and exerts tumor suppressive functions.

MicroRNAs (miRNAs) are small noncoding RNAs that post-transcriptionally regulate gene expression. There have been several reports of miRNA deregulation in prostate cancer (PCa) and the biological evidence for an involvement of miRNAs in prostate tumorigenesis is increasing. In this study, we show that miR-34c is downregulated in PCa (p = 0.0005) by performing qRT-PCR on 49 TURPs from PCa patients compared to 25 from patients with benign prostatic hyperplasia. The miR-34c expression was found to inversely correlate to aggressiveness of the tumor, WHO grade, PSA levels and occurrence of metastases. Furthermore, a Kaplan-Meier analysis of patient survival based on miR-34c expression levels divided into low (&lt; 50th percentile) and high (&gt; 50th percentile) expression, significantly divides the patients into high risk and low risk patients (p = 0.0003, log-rank test). The phenotypic effects of miR-34c deregulation were studied in prostate cell lines, where ectopic expression of miR-34c decreased cell growth, due to both a decrease in cellular proliferation rate and an increase in apoptosis. In concordance to this, miR-34c was found to negatively regulate the oncogenes E2F3 and BCL-2, which stimulates proliferation and suppress apoptosis in PCa cells, respectively. Reversely, we could also show that blocking miR-34c in vitro increases cell growth. Further, ectopic expression of miR-34c was found to suppress migration and invasion. Our findings provide new insight into the role of miR-34c in the prostate, exhibiting tumor suppressing effects on proliferation, apoptosis and invasiveness

Prostate-specific antigen and prostate cancer: prediction, detection and monitoring.

Testing for prostate-specific antigen (PSA) has profoundly affected the diagnosis and treatment of prostate cancer. PSA testing has enabled physicians to detect prostate tumours while they are still small, low-grade and localized. This very ability has, however, created controversy over whether we are now diagnosing and treating insignificant cancers. PSA testing has also transformed the monitoring of treatment response and detection of disease recurrence. Much current research is directed at establishing the most appropriate uses of PSA testing and at developing methods to improve on the conventional PSA test