Prostate adenocarcinoma (PCa) is one of the most prevalent cancers in the world. Second only to lung cancer, the key to its successful treatment is in its early detection. With the introduction of prostate-specific antigen in the early 1990s, a screening test involving measuring levels of this protein was developed to detect PCa in asymptomatic individuals. This test is also known as the PSA test. PCa-specific mortalities have been in decline since the test's introduction. Despite this decline, recent studies have called the efficacy of the PSA test into question. Two large randomized controlled trials conducted in the US and Europe reveal contradicting results as to PSA's accuracy and usefulness. Concerns of overdiagnosis and overtreatment as the result of using PSA screening has led to many national organizations recommending caution or even recommending against its use. Through a thorough review of a large collection of current PCa literature, this study reviews the flaws of using PSA to screen for PCa and investigates alternative approaches currently being pursued through active research to make PCa early detection more accurate. These approaches include improving the accuracy of the PSA screen using PSA-derived testing methods, using PCa-induced epigenetic modifications as a new target for PCa screening, and using urine biomarkers. All of these methods were compared using area under the curve (AUC) values obtained via receiver operating characteristic analysis. Each method has its own flaws but by comparing each of the different approaches, I was able to conclude that out of the currently available screening methods, screening for Engrailed-2 protein in urine is the most promising screening method with the highest AUC values compared to the other methods. Although this method has been introduced in the UK, it has not been introduced in the US yet. Epigenetic screening methods hold the most promise for accurate PCa screening in the future as it confers the highest accuracy in detecting PCa. However, as it hasn't been shown that epigenetic modifications can be easily obtained in the urine or blood serum for easy and accurate screening, I believe more work has to be done in order for it to be successful in being applied as a screening test. By determining the most promising screening type, we can focus resources and efforts towards finding a way to detect PCa early, allowing for successful treatment.

Prostate cancer (PCa) is the most common cancer among men in Western developed countries. While the majority of PCa diagnosed by PSA screening are indolent, advanced and metastatic disease has a significant mortality and morbidity. Bone metastases are extremely common in PCa and identification of bone metastasis associated genes may provide insights into PCa progression and assist in finding new drug targets. However, the genetic study of bone metastases is very limited due to the difficulty of sampling. We performed genome-wide analysis of six fresh frozen PCa bone metastases. We found several alterations commonly present in advanced PCa, including gains at: 1q32.1, broad gains of 8q (MYC, NCOA2), 9q33.2-34.3, 11q13.1-14.1 (CCND1), 12q24.23-24.31, 16p13.3, 16p12.1-11.2 and Xq12-13.1 (AR) as well as losses at: 5q11.1-22.1, 5q14.3-23.1, 6q14.1-22, 8p23.2-p21, 13q13.2-31.1 (RB1), 17p13.1-12 (TP53) and 18q11.1-22.3. Two cases also showed PTEN loss and one sample had deletion indicative of TMPRSS2-ERG fusion. For downstream analysis we concentrated on CCND1 oncogene at 11q13 and FBXL4 at 6q16 as potential drivers of these genomic changes. Using fluorescence in situ hybridisation we found common CCND1 gain and FBXL4 loss in PCa bone metastases (54.5%, 12/22 and 47.8%, 11/23, respectively), much less frequent in primary tumours (7%, 10/142 and 13.8%, 20/145, respectively) and absent in BPH cases (0/55). The expression levels of cyclin D1 protein, coded by CCND1 correlated with CCND1 copy number gain (p < 0.0001) and were higher in metastatic tumours than in primary PCa (p = 0.015), confirming cyclin D1 involvement in advanced PCa. Presence of FBXL4 loss in early stage primary PCa strongly correlated with current PCa prognostic markers and with worse patient survival. Therefore, we propose that FBXL4 may be a tumour suppressor gene in prostate, whose loss in early PCa could be indicative of more aggressive disease. Using in vitro experiments we demonstrated that FBXL4 regulates cells motility and invasion. We confirmed that ERLEC1, an ER lectin involved in ER stress response pathway is a degradation target of FBXL4. As activation of ER stress response pathway is linked to enhanced cell migration and invasion, loss of FBXL4 could be one of the mechanisms by which cancer cells increase their efficiency to respond to stress and to escalate their metastatic potential through stabilisation of ERLEC1. Further studies of FBXL4 - ERLEC1 axis are necessary to establish how they contribute to PCa progression. This knowledge can potentially help to develop novel targeted therapies for aggressive disease harbouring FBXL4 abnormalities.

No description available.

The diagnostic pathway for prostate cancer involves the blood test prostate specific antigen (PSA) which has high sensitivity but low specificity at age related reference ranges. The resultant clinical consequence is a large number of negative diagnostic studies (transrectal ultrasound guided biopsies - TRUS). There is a need for a secondary screening test to help improve on the current diagnostic pathway. Mechanical markers have been used previously to assess the prostate for disease with numerous ex-vivo reports of differences between benign and malignant prostates. There have been no in-vivo studies with direct elasticity assessment devices for prostate cancer detection. This thesis forms part of work in a collaborative study in conjunction with engineers who have created a microscale device, capable of dynamic elasticity assessment. The specific objectives of this thesis were to a) assess dynamic micromechanical markers for the detection and differentiation of clinically significant from insignificant prostate cancer b) to identify relationships between mechanical and histopathological variables in the ex-vivo and in-vivo environments and c) assess the potential for these markers to differentiate peri-prostatic tissues. A prospective study was set-up with full ethics and management approvals with patients undergoing a systematic mechanical assessment of their prostate using the E-finger device and after prostate excision a systematic ex-vivo mechanical assessment on a calibrated stage. The ex-vivo assessment allowed accurate histopathological and mechanical variable assessment in a controlled environment. 7-Tesla ex-vivo MRI scanning aided in assessing the limitations of mechanical assessment of the prostate. There were clear consistent differences between individual dynamic micromechanical markers for benign and tumour containing measurement areas in both environments. Modelling of these dynamic micromechanical markers yielded encouraging accuracy levels for the detection of prostate cancer and differentiation of significant from insignificant disease. There were associations between individual mechanical markers and important histopathological features associated with cancer (acinar size, tumour volume and reactive stroma). These markers showed promise and utility in the differentiation of prostate from bladder and rhabdosphincter. This work demonstrates the clear potential translational uses for dynamic micromechanical markers in the assessment of the prostate for cancer.

Master of Science / Department of Kinesiology / Brad J. Behnke / Introduction: Prostate tumor arterioles lack functional smooth muscle and have a diminished myogenic response. Previous research has demonstrated an enhanced prostate tumor blood flow and oxygenation associated with the augmented mean arterial pressure during exercise. Thus, we tested the hypothesis that elevations in the heart-to-prostate tumor hydrostatic gradient via adoption of the 70˚ head-up tilt (HUT) body position would enhance perfusion of the prostate tumor, which may improve tumor oxygenation and radiation therapy outcomes (Study I). Based upon those findings, we performed a secondary analysis (Study II) on previously published prostate hemodynamic responses to an identical tilt-test between young and aged animals. Methods: Study I: Dunning Cell AT-1 tumor cells (100,000) were injected into the ventral lobe of the prostate in male Copenhagen rats (4 mo.; n = 7). Four to six weeks after injection blood flow to the prostate tumor, kidneys, and soleus muscle was measured via the fluorescent microsphere technique in the supine and HUT position. Study II: A secondary analysis was performed on blood flow to the prostate (host tissue of the tumor) in young (6 mo.; n =9) and aged (24 mo.; n=7) male Fisher 344 rats from Ramsey et al., 2007 (39) to determine potential age-associated differences in conductance to this tissue. Results: Study I: No significant difference was observed in blood pressure between the two body positions. Compared to the supine posture, there was a significant reduction in blood flow to the soleus muscle. There was no difference in prostate tumor blood flow or vascular conductance between the supine and HUT position. Study II: In response to tilt, there was a significant reduction in prostate vascular conductance in young rats versus that in the supine posture (P<0.05). In the aged animals, there was no difference in prostate vascular conductance with tilt. Discussion: Contrary to our hypothesis, we did not see any significant differences in either blood flow or vascular conductance to the prostate tumor with manipulations in body position. Importantly, we believe this may be an age-associated effect. Given tumors both co-opt existing arterioles from the host tissue that retain vasomotor control and develop new vessels that lack functional smooth muscle, the enhanced vascular resistance in the prostate with young animals during tilt likely contributed to the lack of change in tumor perfusion with body position given the rats from study I were also young. Given the lack of change in vascular conductance in the prostate with tilt in aged animals, future studies should be performed in aged models of prostate cancer, of which currently there are no immunocompetent aged rodent models of prostate cancer.

The Defender against apoptotic cell death (DAD1) is a negative regulator of programmed cell death that was initially identified in the temperature sensitive tsBN7 cell line. It has been shown to be an essential subunit of oligosaccharyltransferase and is localized to the Endoplasmic reticulum (ER) in a normal physiological state. However, our data suggests that DAD1 localizes outside of the cell and alters the apoptotic signaling via FAS ligand to give cancer cells a survival advantage. Although the mechanism is poorly understood, increased expression of DAD1 has been associated with increasing Gleason score in prostate cancer (PCa) patient tumors. Based on the aforementioned evidence, our study attempts to unravel cellular localization and the underlying mechanisms by which DAD1 mediates prostate cancer cell survival, and explore its potential as a biomarker in prostate cancer. As evidenced by qRTPCR, immunocytochemistry, immunohistochemistry, Co-ip, ELISA, and immuno-blot analysis, cancer cells down regulate the expression of the binding partner of DAD1 responsible for retention of DAD1 in the ER, which allows DAD1 to exit the ER and be exocytosed. The exocytosed DAD1 binds to FAS L and prevents apoptotic signaling. Treatment with DAD1 antibody induces significantly higher cell death in prostate cancer cells compared to the non-tumorigenic cells. Combination of DAD1 antibody with currently used chemotherapeutic agents like Docetaxel and Doxorubicin can be used to achieve higher cell death at a lower dose of these drugs to minimize side effects. Further, our immunohistochemistry data in tumor microarray suggests that DAD1 could serve as a potential biomarker marker in PCa. In addition to the tissue, we also examined the expression of DAD1 in prostate cancer patient serum samples using sandwich ELISA; our results indicate DAD1 is a more sensitive and specific prognostic marker for prostate cancer compared to PSA. Our data suggests that localization of DAD1 outside of the cells is crucial to the survival of PCa cells and this phenomenon can be exploited to specifically target prostate cancer cells in therapy and serve as a biomarker in prostate cancer. / 1 / Nobel Bhasin

Thesis (Ph. D.)--University of Hong Kong, 2007. / Title proper from title frame. Also available in printed format.

Thesis (Ph.D.)--University of Delaware, 2007. / Principal faculty advisor: Daniel D. Carson, Dept. of Biological Sciences. Includes bibliographical references.

Thesis (M.S.)--University of Delaware, 2007. / Principal faculty advisor: Robert A. Sikes, Dept. of Biological Sciences. Includes bibliographical references.

Thesis (Ph. D.)--Ohio State University, 2006. / Available online via OhioLINK's ETD Center; full text release delayed at author's request until 2007 Jun 14