The Role of the Transcription Factor SIM2 in Prostate Cancer

Background: Recent reports have suggested a possible involvement of Single-minded homolog 2 (SIM2) in human solid cancers, including prostate cancer. However, the exact role of SIM2 in cancer in general, and in prostate cancer in particular, remains largely unknown. This study was designed to elucidate the role of SIM2 in prostate cancer using a shRNA-based approach in the PC3 prostate cancer cell line. Methods: Lentiviral shRNAs were used to inhibit SIM2 gene and protein levels in PC3 cells. Quantitative RT-PCR and branched DNA were performed to evaluate transcript expression. SIM2 protein expression level was measured by western blot. Profiling of gene expression spanning the whole genome, as well as polar metabolomics of several major metabolic pathways was performed to identify major pathway dysregulations. Results: SIM2 gene and protein products were significantly downregulated by lenti-shRNA in PC3 cell line. This low expression of SIM2 affected gene expression profile, revealing significant changes in major signaling pathways, networks and functions. In addition, major metabolic pathways were affected. Conclusion: Taken together, our results suggest an involvement of SIM2 in key traits of prostate tumor cell biology an

Immunization with a Peptide Containing MHC Class I and II Epitopes Derived from the Tumor Antigen SIM2 Induces an Effective CD4 and CD8 T-Cell Response

Here, we sought to determine whether peptide vaccines designed harbor both class I as well as class II restricted antigenic motifs could concurrently induce CD4 and CD8 T cell activation against autologous tumor antigens. Based on our prior genome-wide interrogation of human prostate cancer tissues to identify genes over-expressed in cancer and absent in the periphery, we targeted SIM2 as a prototype autologous tumor antigen for these studies. Using humanized transgenic mice we found that the 9aa HLA-A*0201 epitope, SIM2237–245, was effective at inducing an antigen specific response against SIM2-expressing prostate cancer cell line, PC3. Immunization with a multi-epitope peptide harboring both MHC-I and MHC-II restricted epitopes induced an IFN-γ response in CD8 T cells to the HLA-A*0201-restricted SIM2237–245 epitope, and an IL-2 response by CD4 T cells to the SIM2240–254 epitope. This peptide was also effective at inducing CD8+ T-cells that responded specifically to SIM2-expressing tumor cells. Collectively, the data presented in this study suggest that a single peptide containing multiple SIM2 epitopes can be used to induce both a CD4 and CD8 T cell response, providing a peptide-based vaccine formulation for potential use in immunotherapy of various cancers

A safety-modified SV40 Tag developed for human cancer immunotherapy

Simian virus 40 (SV40)-like DNA sequences have been found in a variety of human tumors, raising the possibility that strategies targeting SV40 may provide a potential avenue for immunotherapy directed against SV40 large T Antigen (Tag)-expressing tumors. We generated a recombinant vaccinia (vac-mTag) expressing mTag and herein assessed the ability of mTag to transform cells and to interact with anti-oncoproteins, as well as screened for the presence of potential HLA-A2.1-restricted epitopes within mTag. We found that transfection of cells with mTag did not lead to their transformation. Also, we demonstrated that mTag protein is degraded rapidly in cells. In addition, our work revealed that mTag did not physically interact with certain anti-oncoproteins. Finally, two potential HLA-A2.1-restricted functional epitopes within mTag sequence were identified. Our results show that mTag lacks the oncogenecity of full-length Tag and harbors potential HLA-A2.1-restricted immunogenic epitopes, hence suggesting the safety of vac-mTag for use in cancer immunotherapy

Detection of prostate cancer-specific transcripts in extracellular vesicles isolated from post-DRE urine

Background: The measurement of gene expression in post-digital rectal examination (DRE) urine specimens provides a non-invasive method to determine a patient’s risk of prostate cancer. Many currently available assays use whole urine or cell pellets for the analysis of prostate cancer-associated genes, although the use of extracellular vesicles (EVs) has also recently been of interest. We investigated the expression of prostate-, kidney-, and bladder- specific transcripts and known prostate cancer biomarkers in urine EVs. Methods: Cell pellets and EVs were recovered from post-DRE urine specimens, with the total RNA yield and quality determined by Bioanalyzer. The levels of prostate, kidney, and bladder- associated transcripts in EVs were assessed by TaqMan qPCR and targeted sequencing. Results: RNA was more consistently recovered from the urine EV specimens, with over 80% of the patients demonstrating higher RNA yields in the EV fraction as compared to urine cell pellets. The median EV RNA yield of 36.4 ng was significantly higher than the median urine cell pellet RNA yield of 4.8 ng. Analysis of the post-DRE urine EVs indicated that prostate-specific transcripts were more abundant than kidney- or bladder-specific transcripts. Additionally, patients with prostate cancer had significantly higher levels of the prostate cancer-associated genes PCA3 and ERG. Conclusions: Post-DRE urine EVs are a viable source of prostate-derived RNAs for biomarker discovery and prostate cancer status can be distinguished from analysis of these specimens. Continued analysis of urine EVs offers the potential discovery of novel biomarkers for pre- biopsy prostate cancer detection

Localized prostate cancer in Norway, the United States, and Spain: between-country differences of variables before treatment among patients eligible for curative treatment

Between-country differences in medical and sociodemographic variables, and patient-related outcomes (PROs) before treatment might explain published variations of side effects after radical prostatecomy (RP) or radiotherapy (RAD) for prostate cancer (PCa). This hypothesis was tested among 1908 patients from the United States, Spain, and Norway. Significant between-country differences were observed for most factors investigated before treatment. The observations should be considered in comparison of the frequency and severity of internationally published studies. Background: In men with PCa, large variations of PROs after RP or high-dose RAD might be related to betweencountry differences of medical and sociodemographic variables, and differences in PROs before treatment in the sexual and urinary domains. Patients and Methods: In 1908 patients with localized PCa from Norway, the United States, or Spain, the relation between medical (prostate-specific antigen, Gleason score, cT-category) and sociodemographic variables (age, education, marital status) before treatment was investigated. Using the Expanded Prostate Cancer Index Composite questionnaire, PROs before treatment within the sexual and urinary domains were also considered. Results: Compared with the European patients, American patients were younger, fewer had comorbid conditions, and more had a high education level. Fifty-three percent of the US men eligible for RP had low-risk tumors compared with 42% and 31% among the Norwegian and the Spanish patients, respectively. Among the Spanish RAD patients, 54% had had low-risk tumors compared with 34% of the American and 21% of the Norwegian men planned for RAD, respectively. Compared with the European patients, significantly fewer US patients reported moderate or severe sexual dysfunction and related problems. In most subgroups, the number of patients with sexual or urinary dysfunction exceeded that of patients with bother related to the reported dysfunction. Conclusion: Statistically significant between-country differences were observed in medical and sociodemographic variables, and in PROs before treatment within the sexual and urinary domains. Large differences between reported dysfunction and related problems within the sexual and urinary domains indicate that dysfunction and bother should be reported separately in addition to calculation of summary scores. The documented differences, not at least regarding PROs, might in part explain the large variation of side effects after treatment evident in the medical literatur

Antigen-specific tumor vaccine efficacy in vivo against prostate cancer with low class I MHC requires competent class II MHC

BACKGROUND Cancers can escape immune recognition by means of evading class I major histocompatibility complex (MHC) -mediated recognition by cytotoxic T lymphocytes. However, immunization strategies targeting defined tumor-associated antigens have not been extensively characterized in murine prostate cancer models. Therefore, we evaluated antigen-specific, antitumor immunity after antigen-encoding vaccinia immunization against mouse prostate cancer cells expressing a model tumor-associated antigen (Β-galactosidase) and exhibiting partially deficient class I MHC. METHODS AND RESULTS Low class I MHC expression in Β-galactosidase–expressing D7RM-1 prostate cancer cells was shown by fluorescence activated cell sorting, and deficient class I MHC-mediated antigen presentation was shown in resistance of D7RM-1 to cytolysis by Β-galactosidase–specific cytotoxic T lymphocytes (CTL). Despite partially deficient class I MHC presenting function, immunization with vaccinia encoding Β-galactosidase conferred antigen-specific protection against D7RM-1 cancer. Antigen-specific immunity was recapitulated in Β 2 m knockout mice (with deficient class I MHC and CTL function), confirming that class I MHC antigen presentation was not required for immunity against tumor partially deficient in class I MHC. Conversely, antigen-specific antitumor immunity was abrogated in A b Β knockout mice (with deficient class II MHC and helper T cell function), demonstrating a requirement for functional class II MHC. Resistant tumors from the otherwise effectively immunized Β 2 m knockout mice (among which tumor progression had been reduced or delayed) showed reduced target antigen expression, corroborating antigen-specificity (and showing an alternative immune escape mechanism), whereas antigen expression (like tumor growth) was unaffected among A b Β knockout mice. CONCLUSION Our results demonstrate that class I MHC-restricted antigen presentation and CTL activity is neither necessary nor sufficient for antigen-encoding vaccinia immunization to induce protective immunity against class I MHC-low tumors, whereas host class II MHC-mediated antigen presentation facilitates antigen-specific immunity against prostate cancer in vivo. Reduced expression of the target antigen developed rapidly in vivo as an immune escape mechanism for such cancers. Prostate 53: 183–191, 2002. © 2002 Wiley-Liss, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/34762/1/10136_ftp.pd

Comparative effectiveness study of patient‐reported outcomes after proton therapy or intensity‐modulated radiotherapy for prostate cancer

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/106701/1/cncr28536.pd

Patient‐reported outcomes after 3‐dimensional conformal, intensity‐modulated, or proton beam radiotherapy for localized prostate cancer

BACKGROUND: Recent studies have suggested differing toxicity patterns for patients with prostate cancer who receive treatment with 3‐dimensional conformal radiotherapy (3DCRT), intensity‐modulated radiotherapy (IMRT), or proton beam therapy (PBT). METHODS: The authors reviewed patient‐reported outcomes data collected prospectively using validated instruments that assessed bowel and urinary quality of life (QOL) for patients with localized prostate cancer who received 3DCRT (n = 123), IMRT (n = 153) or PBT (n = 95). Clinically meaningful differences in mean QOL scores were defined as those exceeding half the standard deviation of the baseline mean value. Changes from baseline were compared within groups at the first post‐treatment follow‐up (2‐3 months from the start of treatment) and at 12 months and 24 months. RESULTS: At the first post‐treatment follow‐up, patients who received 3DCRT and IMRT, but not those who received PBT, reported a clinically meaningful decrement in bowel QOL. At 12 months and 24 months, all 3 cohorts reported clinically meaningful decrements in bowel QOL. Patients who received IMRT reported clinically meaningful decrements in the domains of urinary irritation/obstruction and incontinence at the first post‐treatment follow‐up. At 12 months, patients who received PBT, but not those who received IMRT or 3DCRT, reported a clinically meaningful decrement in the urinary irritation/obstruction domain. At 24 months, none of the 3 cohorts reported clinically meaningful changes in urinary QOL. CONCLUSIONS: Patients who received 3DCRT, IMRT, or PBT reported distinct patterns of treatment‐related QOL. Although the timing of toxicity varied between the cohorts, patients reported similar modest QOL decrements in the bowel domain and minimal QOL decrements in the urinary domains at 24 months. Prospective randomized trials are needed to further examine these differences. Cancer 2013. © 2013 American Cancer Society. Prostate cancer patients who receive 3‐dimensional conformal radiotherapy, intensity‐modulated radiotherapy, or proton beam therapy report distinct patterns of treatment‐related quality of life. Although the timing of toxicity varies between cohorts, patients report similar modest quality‐of‐life decrements in the bowel domain and minimal QOL decrements in the urinary domains at 24 months.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/97476/1/27956_ftp.pd

Use of quality indicators to evaluate the care of patients with localized prostate carcinoma

BACKGROUND The goal of quality assurance in health care is to preserve and improve patient care. Recently, RAND developed a set of evidence-based candidate indicators for evaluating the quality of care for patients with localized prostate carcinoma; however, the feasibility and sensitivity of these indicators have not been tested in a clinical setting. The objectives of this study were to evaluate the feasibility of measuring these quality indicators and to determine their sensitivity to change in practice patterns over time. METHODS One hundred sixty-eight men who presented in either 1995 or in 2000 and were treated for localized prostate carcinoma were selected randomly from the University of Michigan tumor registry. A combination of electronic data base review and explicit chart review was used to assess the feasibility of measuring compliance for each indicator. For each indicator in which assessment was feasible, compliance with the RAND indicators was determined for patients in both years. Multivariate regression analysis was used to adjust for potential confounding effects of disease stage, tumor grade, prostate specific antigen (PSA) level, patient age, and therapy. RESULTS Based on review of available clinical data, measurement of compliance was feasible for 19 of 22 RAND candidate quality indicators (86%). For five indicators, significant differences in documentation (compliance) were detected between 1995 and 2000 ( P < 0.05). Treatment received and higher PSA levels were associated independently with documentation of compliance for several indicators ( P < 0.05). CONCLUSIONS Measurement of the majority of the RAND quality indicators for the treatment of patients with localized prostate carcinoma was feasible, and improvements in several indicators were observed between 1995 and 2000. Demonstration of such variation, even within a single institution, suggests that the indicators are sufficiently sensitive to detect differences in practice patterns. Cancer 2003;97:1428–35. © 2003 American Cancer Society. DOI 10.1002/cncr.11216Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/34367/1/11216_ftp.pd

Recommended Patient-Reported Core Set of Symptoms to Measure in Prostate Cancer Treatment Trials

The National Cancer Institute (NCI) Symptom Management and Health-Related Quality of Life Steering Committee convened four working groups to recommend core sets of patient-reported outcomes to be routinely incorporated in clinical trials. The Prostate Cancer Working Group included physicians, researchers, and a patient advocate. The group’s process included 1) a systematic literature review to determine the prevalence and severity of symptoms, 2) a multistakeholder meeting sponsored by the NCI to review the evidence and build consensus, and 3) a postmeeting expert panel synthesis of findings to finalize recommendations. Five domains were recommended for localized prostate cancer: urinary incontinence, urinary obstruction and irritation, bowel-related symptoms, sexual dysfunction, and hormonal symptoms. Four domains were recommended for advanced prostate cancer: pain, fatigue, mental well-being, and physical well-being. Additional domains for consideration include decisional regret, satisfaction with care, and anxiety related to prostate cancer. These recommendations have been endorsed by the NCI for implementation