Expression of ERG oncoprotein is associated with a less aggressive tumor phenotype in Japanese prostate cancer patients

To investigate and characterize ERG oncoprotein expression in Japanese patients with prostate cancer (PCa), we evaluated 92 index tumors from Japanese patients who had undergone radical prostatectomy for PCa, using an antibody‐based detection method to determine ERG expression. Expression status was compared with clinicopathological findings including patient age, body mass index and preoperative prostate‐specific antigen (PSA) levels, specimen Gleason score, pathological stage, positive surgical margin, size of index tumor, prostatic volume, zonal origin of index tumor and biochemical failure. Overall, ERG protein was expressed in 16.3% (15/92) of the index tumors, but not in benign glands. Younger patient age, lower Gleason score and negative surgical margins were found to be independently associated with its expression in the multivariate analysis (P= 0.015, 0.003 and 0.038, respectively). ERG expression was not associated with biochemical failure. Though not statistically significant, ERG expression was more frequently observed in peripheral zone than in transition zone cancers (28.2% vs 10%, respectively). In conclusion, ERG protein was less frequently expressed in this Japanese PCa cohort compared with Western reports. ERG expression was associated with a less aggressive tumor phenotype, and its biological significance needs to be further investigated.     

Immunohistochemical ETS-related gene detection in a Japanese prostate cancer cohort: diagnostic use in Japanese prostate cancer patients

Chromosomal rearrangements that result in high expression levels of the ETS-related gene (ERG) present in approximately 50% of prostate cancer (PCa) patients, making this one of the most common oncogenic alterations in PCa. However, ERG overexpression at the protein level has not been rigorously evaluated in Japanese PCa patients. In this study, we evaluated ERG expression using antibody-based detection in 230 prostate specimens in a Japanese PCa cohort. Overall, we identified 20.1% ERG-positive PCa cases. ERG was not detected in benign glands. The specificity of ERG staining for detecting PCa was almost 100%; all of the ERG-positive samples were also diagnosed as PCa. The expression level of the ERG protein correlated with clinicopathological variables, including grade (P= 0.038), stage (P= 0.005), and metastatic status (P= 0.014). No correlation was observed with age (P= 0.196) or with preoperative prostate-specific antigen level (P= 0.322). Although the frequency of ERG-positive cases in Japanese PCa patients (20.1%) was lower than that reported in a PCa cohort in Western countries (approximately 50%), our study demonstrates that the clinical utility of ERG detection at the protein level can serve as an ancillary tool for diagnosing PCa in the Japanese population.     

Generation of Potent Cytotoxic T Lymphocytes Against Castration‐Resistant Prostate Cancer Cells by Dendritic Cells Loaded With Dying Allogeneic Prostate Cancer Cells

To induce a potent cytotoxic T lymphocyte (CTL) response in dendritic cell (DC)‐based immunotherapy against prostate cancer, various tumour antigens should be loaded onto DCs. The aim of this study was to establish a method of immunotherapy for castration‐resistant prostate cancer (CRPC) using prostate cancer–specific CTLs generated in vitro by DCs. Monocyte‐derived DCs from patients with CRPC were induced to mature using a standard cytokine cocktail (in IL‐1β, TNF‐α, IL‐6 and PGE₂: standard DCs, sDCs) or using an α‐type 1‐polarized DC (αDC1) cocktail (in IL‐1β, TNF‐α, IFN‐α, IFN‐γ and polyinosinic:polycytidylic acid) and loaded with the UVB‐irradiated CRPC cell line PC‐3. Antigen‐loaded DCs were evaluated by morphological and functional assays. The αDC1s significantly increased the expression of several molecules related to DC maturation, regardless of whether the αDC1s were loaded with tumour antigens or not, compared to sDCs. The αDC1s showed a higher production of interleukin‐12 both during maturation and after subsequent stimulation with CD40L, which was not significantly affected by loading with tumour antigens, as compared to standard DCs (sDCs). Prostate cancer–specific CTLs against autologous CRPC cells were successfully induced by αDC1s loaded with dying PC‐3 cells. Autologous αDC1s loaded with an allogeneic CRPC cell line can generate greater CRPC‐specific CTL responses as compared to sDCs and may provide a novel source of DC‐based vaccines that can be used for the development of immunotherapy in patients with CRPC.     

Somatic copy number alterations by whole‐exome sequencing implicates YWHAZ and PTK2 in castration‐resistant prostate cancer

Castration‐resistant prostate cancer (CRPC) is the most aggressive form of prostate cancer (PCa) and remains a significant therapeutic challenge. The key to the development of novel therapeutic targets for CRPC is to decipher the molecular alterations underlying this lethal disease. The aim of our study was to identify therapeutic targets for CRPC by assessing somatic copy number alterations (SCNAs) by whole‐exome sequencing on five CRPC/normal paired formalin‐fixed paraffin‐embedded (FFPE) samples, using the SOLiD4 next‐generation sequencing (NGS) platform. Data were validated using fluorescence in situ hybridization (FISH) on a PCa progression cohort. PTK2 and YWHAZ amplification, mRNA and protein expression were determined in selected PCa cell lines. Effects of PTK2 inhibition using TAE226 inhibitor and YWHAZ knock‐down on cell proliferation and migration were tested in PC3 cells in vitro. In a larger validation cohort, the amplification frequency of YWHAZ was 3% in localized PCa and 48% in CRPC, whereas PTK2 was amplified in 1% of localized PCa and 35% in CRPC. YWHAZ knock‐down and PTK2 inhibition significantly affected cell proliferation and migration in the PC3 cells. Our findings suggest that inhibition of YWHAZ and PTK2 could delay the progression of the disease in CRPC patients harbouring amplification of the latter genes. Furthermore, our validated whole‐exome sequencing data show that FFPE tissue could be a promising alternative for SCNA screening using next‐generation sequencing technologies. Copyright © 2013 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.     

PTEN loss in intraductal carcinoma of the prostate has low incidence in Japanese patients

Clinical and genomic features of prostate cancer (PCa) vary considerably between Asian and Western populations. PTEN loss is the most frequent abnormality in intraductal carcinoma of the prostate (IDC-P) in Western populations. However, its prevalence and significance in Asian populations have not yet been well studied. In the present study, we evaluated PTEN expression in IDC-P in a Japanese population and its association with ERG expression. This study included 45 and 59 patients with PCa with and without IDC-P, respectively, who underwent radical prostatectomy. PTEN loss was observed in 10 patients with PCa with IDC-P (22%) and nine patients with PCa without IDC-P (17%). ERG expression was relatively frequent in patients with PCa with PTEN loss, although a significant difference was not observed. The co-occurrence of PTEN loss and ERG expression was observed in four patients with PCa with IDC-P and one without IDC-P. PTEN loss and ERG expression did not affect progression-free survival, regardless of the presence of IDC-P. The frequency of PTEN loss in IDC-P is lower in Asian patients than in Western patients. Our results indicate that mechanisms underlying IDC-P in Asian populations are different from those of Western populations.     

Expression of prostate stem cell antigen in high-grade prostatic intraepithelial neoplasia and prostate cancer

Barbisan F, Mazzucchelli R, Santinelli A, Scarpelli M, Lopez‐Beltran A, Cheng L & Montironi R (2010) Histopathology 57 , 572–579
Expression of prostate stem cell antigen in high‐grade prostatic intraepithelial neoplasia and prostate cancer Aims: To investigate prostate stem cell antigen (PSCA) and Ki‐67 expression in normal‐looking epithelium (NEp), atrophy, high‐grade prostatic intraepithelial neoplasia (HGPIN) and prostatic adenocarcinoma (PCa). Methods and results: PSCA and Ki‐67 were evaluated immunohistochemically in NEp, atrophy, HGPIN and PCa in 20 radical prostatectomies (RPs) and 20 cystoprostatectomies (CyPs). The proportions of PSCA positive cells and of cases with PSCA expression increased from NEp through atrophy and HGPIN to PCa. The differences between NEp and HGPIN and PCa and between atrophy and HGPIN and PCa were statistically significant for the away and adjacent locations, in both the RP and CyP groups. The differences between HGPIN and PCa were statistically significant in the RP group when it was away from PCa and in the CyP group when it was adjacent to and away from PCa. The values in the RPs were slightly greater than in the CyPs, the differences being not statistically significant. The proportions of Ki‐67 positive nuclei increased from atrophy and NEp to HGPIN and PCa. The correlation between the proportion of Ki‐67 positive nuclei and that of PSCA‐positive cells was statistically significant. Conclusions: PSCA expression, deregulated in atrophy and HGPIN, is a marker associated with neoplastic transformation of prostate cells, both in RPs and CyPs.     

Androgen depletion up‐regulates cadherin‐11 expression in prostate cancer

Men with castration‐resistant prostate cancer (PCa) frequently develop metastasis in bone. The reason for this association is unclear. We have previously shown that cadherin‐11 (also known as OB‐cadherin), a homophilic cell adhesion molecule that mediates osteoblast adhesion, plays a role in the metastasis of PCa to bone. Here, we report that androgen‐deprivation therapy up‐regulates cadherin‐11 expression in PCa. In human PCa specimens, immunohistochemical staining showed that 22/26 (85%) primary PCa tumours from men with castration‐resistant PCa expressed cadherin‐11. In contrast, only 7/50 (14%) androgen‐dependent PCa tumours expressed cadherin‐11. In the MDA–PCa‐2b xenograft animal model, cadherin‐11 was expressed in the recurrent tumours following castration. In the PCa cell lines, there is an inverse correlation between expression of cadherin‐11 and androgen receptor (AR), and cadherin‐11 is expressed in very low levels or not expressed in AR‐positive cell lines, including LNCaP, C4‐2B4 and VCaP cells. We showed that AR likely regulates cadherin‐11 expression in PCa through an indirect mechanism. Although re‐expression of AR in the AR‐negative PC3 cells led to the inhibition of cadherin‐11 expression, depletion of androgen from the culture medium or down‐regulation of AR by RNA interference in the C4‐2B4 cells or VCaP cells only produced a modest increase of cadherin‐11 expression. Promoter analysis indicated that cadherin‐11 promoter does not contain a typical AR‐binding element, and AR elicits a modest inhibition of cadherin‐11 promoter activity, suggesting that AR does not regulate cadherin‐11 expression directly. Together, these results suggest that androgen deprivation up‐regulates cadherin‐11 expression in prostate cancer, and this may contribute to the metastasis of PCa to bone. Our study suggests that therapeutic strategies that block cadherin‐11 expression or function may be considered when applying androgen‐ablation therapy. Copyright © 2010 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.     

Association between radical prostatectomy and risk of herpes zoster

The present study investigated the association between radical prostatectomy (RP) and the risk of herpes zoster (HZ). Male patients aged?≥?40 years and diagnosed with prostate cancer (PCa) between 2000 and 2005 were included in this study. Patients who underwent RP for the first time during 2000–2006 were included in the RP group. Randomly selected individuals from among the remaining patients with PCa who did not undergo RP were included in the non-RP group. Univariate and multivariate Cox regression models were used to analyze the association between PCa and HZ. In addition, the association between RP and the risk of HZ in different subgroups was evaluated after stratification by age, comorbidities, and hormone therapy (HoT) status. Furthermore, the combined effect of RP and HoT on the risk of HZ was evaluated. This study included 1,380 patients with PCa who newly underwent RP and 1,371 patients with PCa who did not undergo RP. During follow-up, 96 and 104 patients in the RP and non-RP groups, respectively, developed HZ. Patients who underwent both RP and HoT showed a significantly reduced risk of HZ, compared with patients who did not undergo both RP and HoT. RP is not associated with an increased risk of HZ. However, prostate-specific antigen levels should be monitored routinely during follow-up to detect PCa recurrence.     

前列腺癌组织中Skp2、p27的表达及临床意义

目的 研究前列腺癌(prostate cancer,PCa)组织中细胞S相激酶相关蛋白2(Skp2)、p27蛋白的表达及临床意义.方法 选取2016年1月至2017年1月我院120例PCa住院患者手术标本纳入研究,依据分化程度差异将PCa分为低分化组(n=56)、中分化组(n=28)与高分化组(n=36),并将这120例患者癌旁组织纳入对照组(n=120),以免疫组化法分析Skp2、p27在PCa中表达程度及PCa危险因素等级之间相关性.结果 PCa组Skp2阳性表达率(53.33％)明显高于对照组(23.33％),且p27蛋白阳性表达率(41.67％)明显低于对照组(86.67％);高、中、低分化组Skp2阳性表达率排序为:高＜中＜低,三组比较差异具有统计学意义(P＜0.05);高、中、低分化组p27蛋白阳性表达率排序为:高＞中＞低,三组比较差异具有统计学意义(P ＜0.05);Skp2阴性表达组术前PSA水平＜4μg/L比例(67.86％)与肿瘤穿透前列腺被膜比例(89.29％)明显高于阳性组(28.13％、62.50％)(P＜0.05);p27蛋白阴性表达组术前PSA水平＜4μg/L比例(31.43％)与肿瘤穿透前列腺被膜比例(68.57％)明显低于阳性组(68.00％、92.00％)(P＜0.05);Skp2表达与PCa危险因素等级具有正相关关系(r =0.513,P＜0.05),而p27蛋白表达与PCa危险因素等级具有负相关关系(r=-0.747,P＜0.05).结论 PCa组织中,Skp2为高表达,p27蛋白为低表达,和PCa分化程度存在紧密联系,Skp2与p27蛋白的检测能够为PCa的发生、发展及患者治疗提供帮助.     

Cancer/testis antigen SPATA19 is frequently expressed in benign prostatic hyperplasia and prostate cancer

Spermatogenesis‐associated 19 (SPATA19) is a cancer/testis antigen overexpressed in various cancers. However, its protein expression profile in malignant or non‐malignant tissues remains unknown. Thus, in this study, we investigated SPATA19 protein expression patterns in a panel of non‐malignant human samples and primary prostate cancer (PCa) with or without benign prostatic hyperplasia (BPH) tissues. SPATA19 was absent in all non‐malignant tissues investigated (n=14) except testis and prostate tissues. In terms of malignancies, all PCa cases were positive for SPATA19 exhibiting frequency between 20 and 100% (median 85%) with 63 (52.5%) and 57 (47.5%) cases demonstrating weak/moderate and strong intensities, respectively. Thirty‐nine PCa cases (32.5%) contained BPH, and all BPH glands were SPATA19 positive (frequency between 20 and 100%; median 90%) with 13 (33.3%) demonstrating strong SPATA19 expression. Higher SPATA19 expression (higher frequency, intensity, or H‐score) was not associated with overall survival or disease‐specific survival (DFS) in all PCa cases. However, biochemical recurrence (BR) was associated with worse DFS (p = 0.005) in this cohort of 120 patients, and cases with strong SPATA19 intensity were associated with BR (p = 0.020). In conclusion, we showed that SPATA19 protein was frequently expressed in both BPH and PCa glands, and this warrants future investigations on its pathogenic roles in the disease.     

Nuclear C-MYC expression level is associated with disease progression and potentially predictive of two year overall survival in prostate cancer

Purpose: Upregulation of nuclear C-MYC protein has been reported to be an early event in prostate cancer (PCa); however, its clinicopathological and prognostic significance remain controversial. We determined the association of nuclear C-MYC protein expression with clinicopathological parameters, prognosis, ETS-related gene (ERG) expression, and TMPRSS2-ERG status in PCa. Methods: Nuclear C-MYC and ERG expression by immunohistochemistry and TMPRSS2-ERG status by triple-color probe fluorescence in situ hybridization assay were determined in 50 hormone-naïve PCa patients and 31 radical prostatectomy specimens. Results: Nuclear C-MYC immunostaining was negative, positive, and strong positive in 27.5%, 32.5%, and 40.0% of cases, respectively. C-MYC immunostaining was significantly associated with clinical T stage (P < 0.001), distant metastasis at the time of diagnosis (P < 0.001) and TMPRSS2-ERG status (P = 0.001) but not with ERG immunostaining (P = 0.818). In the Kaplan-Meier analysis, C-MYC positive cases were found to have worse 2-year OS compared with C-MYC negative cases (P = 0.027). However, in the univariate Cox analysis, only TMPRSS2-ERG status (hazard ratio [HR] 0.189, 95% CI 0.057-0.629; P = 0.007) and distant metastasis (HR 3.545, 95% CI 1.056-11.894; P = 0.040) were significantly associated with 2-year OS. After adjusting for these two factors, TMPRSS2-ERG status still impacted 2-year OS (HR 0.196, 95% CI 0.049-0.778; P = 0.020). Conclusions: Nuclear C-MYC overexpression may be associated with disease progression and potentially predictive of 2-year OS in PCa. This is the first study to demonstrate an association between nuclear C-MYC immunostaining and TMPRSS2-ERG status in PCa.     

Increased levels of serum miR‐148a‐3p are associated with prostate cancer

Prostate cancer (PCa) is one of the most common types of cancer and the fifth leading cause of death among men worldwide. The tools for diagnosing PCa have limited value, and to improve correct diagnosis there is a need for markers that can contribute to a more precise diagnosis, which would lead to proper treatment of only those patients who need it. Micro RNA (miRNA) plays a key role in the development of cancer and is therefore a potential marker for PCa. Next‐generation sequencing was used to discover differences in miRNA expression between serum samples from PCa patients and healthy controls, and the results were validated by quantitative real‐time polymerase chain reaction. Detection of the miRNA of interest was attempted in prostate tissue by in situ hybridization. All samples were collected in collaboration with Biobank1^®. By miRNA sequencing of serum samples, significant expression of some miRNAs in patients with PCa and healthy controls was detected. This study showed that miR‐148a‐3p is upregulated in men with PCa, and the miRNA is differentially expressed in PCa patients compared to healthy controls. The results also showed that miR‐148a‐3p is located in prostate tissue.     

Large‐scale genomic instability in colon adenocarcinomas and correlation with patient outcome

The purpose of this study was to evaluate the association between DNA content in colon adenocarcinomas using high‐resolution image cytometry and patient outcome. Tumours from 219 patients operated for colon adenocarcinoma were analysed using high‐resolution image cytometry. Proteins involved in cell cycle propulsion (cyclins A, D1, D3 and E) and cell proliferation (c‐Myc and non‐membranous β‐catenin) have previously been reported in the same cohort and were included in this study. The results were related to disease‐free survival and to cancer‐specific death. Patients with aneuploid tumours showed shorter relapse‐free survival than patients with euploid tumours (univariate log‐rank test, p = 0.004 and multivariate Cox regression model p = 0.009, HR 0.51, 95% CI 0.31–0.84). Also the risk of death from cancer was greater in patients with aneuploid tumours (log‐rank test, p = 0.006 multivariate Cox regression model p = 0.014, HR 0.47, 95% CI 0.26–0.86). When analysing patients with Dukes stages A and B, nuclear expression of β‐catenin was highly significantly associated with both shorter relapse‐free survival (p < 0.005, HR 5.0, 95% CI 1.6–15.5) and cancer‐specific death (p = 0.036, HR 6.9, 95% CI 1.1–42.1). DNA content in colon adenocarcinomas measured by image cytometry is an independent predictor of prognosis in our patients operated for colon adenocarcinoma.     

ERG rearrangement in local recurrences compared to distant metastases of castration-resistant prostate cancer

Castration-resistant prostate cancer is the second most common cause of cancer death and results in a median survival of less than 2?years. In prostate cancer, fusions between TMPRSS2 and ERG are common. The ERG rearrangement prevalence in local recurrent castration-resistant prostate cancer compared to distant metastatic prostate cancer is unknown. We investigated the frequency of ERG rearrangement in local recurrent castration-resistant prostate cancer compared to distant metastatic prostate cancer, and assessed for associations between androgen receptor (AR) amplification and ERG rearrangement status. Samples from 134 patients diagnosed with prostate cancer (84 local recurrent castration resistant prostate cancer, 55 distant metastatic prostate cancer) were assessed for their ERG rearrangement and AR amplification status by fluorescence in situ hybridization. Statistical analysis was performed using the χ (2) test. We found that the ERG rearrangement occurs at a significantly lower frequency in distant metastatic prostate cancer (25?%) than in local recurrent castration-resistant prostate cancer (45?%). The AR amplification frequencies were 45 and 35?% in local recurrent castration-resistant prostate cancer and distant metastatic prostate cancer, respectively. The ERG rearrangement occurred at a lower frequency in distant metastatic prostate cancer compared to local recurrent castration-resistant prostate cancer.     

alpha-Methylacyl coenzyme A racemase, Ki-67, and topoisomerase IIalpha in cystoprostatectomies with incidental prostate cancer

alpha-Methylacyl coenzyme A racemase (AMACR), Ki-67, and topoisomerase IIalpha were immunohisto-chemically evaluated in prostate carcinoma (PCa), high-grade prostatic intraepithelial neoplasia (HPIN), normal-looking epithelium (NEp), and atrophy in 20 cystoprostatectomy (CyP) and 20 radical prostatectomy (RP) specimens with pT2a Gleason score 6 PCa. The aim was to see whether there were differences in marker expression between CyP and RP specimens. The results showed that the proportions of AMACR-, Ki-67-, and topoisomerase IIalpha-positive cells in the CyP and RP specimens increased from NEp and atrophy through HPIN, away from and adjacent to PCa, to PCa. AMACR expression in PCa in CyP specimens was slightly lower than in RP specimens, but the differences were not significant; there were significant differences in Ki-67 and topoisomerase IIalpha indices. Our findings in marker expression in NEp, atrophy, and HPIN suggest that there are some differences in the field effects in terms of prostatic carcinogenesis between CyP and RP specimens.