PTEN and ERG expression in MRI-ultrasound guided fusion biopsy correlated with radical prostatectomy findings in men with prostate cancer.

BACKGROUND: Conventional systematic prostate biopsies (SBx) have multiple limitations, and magnetic resonance imaging (MRI)-ultrasound fusion targeting is increasingly applied (fusion biopsies [FBx]). In our previous studies, we have shown that loss of the tumor suppressor gene phosphatase and tensin homolog (PTEN) in radical prostatectomy (RP) specimens predicts poor disease-specific survival, and in active surveillance (AS), PTEN loss in SBx predicts an adverse AS outcome, although SBx PTEN status does not correlate well with the corresponding RP status. Here, we have hypothesized that PTEN and erythroblast transformation-specific related gene (ERG) status in FBx correlate better with RP than they would in SBx. METHODS: A total of 106 men, who had undergone FBx and subsequent RP in a single center between June 2015 and May 2017 were included. Fifty-three of the men had concomitant or previous SBx's. All biopsy and RP specimens were collected, and tissue microarrays (TMA) were constructed from RP specimens. Immunohistochemical stainings for PTEN and ERG expression were conducted on biopsies and RP TMAs and results were compared by using Fisher's exact test. RESULTS: The immunohistochemical predictive power of FBx, determined by the concordance of biopsy PTEN and ERG status with RP, is superior to SBx (77.6% vs 66.7% in PTEN, 92.4% vs 66.6% in ERG). FBx was superior to SBx in correlation with RP Gleason Grade Groups and MRI prostate imaging reporting and data system scores. CONCLUSION: FBx grading correlates with RP histology and MRI findings and predicts the biomarker status in the RP specimens more accurately than SBx. A longer follow-up is needed to evaluate if this translates to better prediction of disease outcomes, especially in AS and radiation therapy where prostatectomy specimens are not available for prognostication.

Reduced KLK2 expression is a strong and independent predictor of poor prognosis in ERG-negative prostate cancer.

BACKGROUND: Kallikrein-related peptidase 2 (KLK2)-like KLK3 (prostate-specific antigen [PSA])-belongs to the highly conserved serine proteases of the glandular kallikrein protein family (KLK family). Studies suggested that measurement of KLK2 serum levels advanced the predictive accuracy of PSA testing in prostate cancer. METHODS: To clarify the potential utility of KLK2 as a prognostic tissue biomarker, KLK2 expression was analyzed by immunohistochemistry in more than 12 000 prostate cancers. RESULTS: Normal epithelium cells usually showed weak to moderate KLK2 immunostaining, whereas KLK2 was negative in 23%, weak in 38%, moderate in 35%, and strong in 4% of 9576 analyzable cancers. Lost or reduced KLK2 immunostaining was associated with advanced tumor stage, high Gleason score, lymph node metastasis, increased cell proliferation, positive resection margin, and early PSA recurrence (P < .0001). Comparison with previously analyzed molecular alterations revealed a strong association of KLK2 loss and presence of TMPRSS2:ERG fusion (P < .0001), most of all analyzed common deletions (9 of 11; P ≤ .03), and decreased PSA immunostaining (P < .0001 each). Cancers with combined negative or weak immunostaining of KLK2 and PSA showed worse prognosis than cancers with at least moderate staining of one or both proteins (P < .0001). Multivariate analyses including established preoperative and postoperative prognostic parameters showed a strong independent prognostic impact of KLK2 loss alone or in combination of PSA, especially in erythroblast transformation-specific-negative cancers (P ≤ .006). CONCLUSIONS: Loss of KLK2 expression is a potentially useful prognostic marker in prostate cancer. Analysis of KLK2 alone or in combination with PSA may be useful for estimating cancer aggressiveness at the time of biopsy.

KPNA2/ERG Coexpression is Associated With Early Recurrence in Advanced Prostate Cancers.

Most prostate cancers (PC) overexpress the ERG oncogene and karyopherin α 2 (KPNA2). These genes play a role in prostatic carcinogenesis, but their prognostic significance is still debated. The aim of this study was to determine the prognostic significance of ERG and KPNA2 expression, and their association to early prostate-specific antigen (PSA) biochemical recurrence in advanced PC with lymph node metastases. A series of 65 consecutive pN1 M0 R0 PC samples obtained by radical prostatectomy with lymphadenectomy has been analyzed for ERG and KPNA2 expression by immunohistochemistry. For each case, the following clinical data were collected: age, preoperative serum PSA levels, Gleason grade group, TNM stage, and follow-up. PC recurrence was investigated by serum PSA assay and defined by a PSA concentration >0.2 ng/mL after a nadir of <0.1 ng/mL following radical prostatectomy. ERG-positive staining was found in 25/65 cases (38%), and KPNA2 in 56/65 cases (86%); neither was detected in normal prostatic tissue. Immunohistochemical concordance was found between primary tumor and lymph node metastases in 24/25 (96%) of ERG and 53/56 (95%) of KPNA2-positive cases. The follow-up was known in all cases, and early PSA recurrence occurred in 25/65 cases (38%). ERG positivity, both alone and in conjunction with KPNA2 positivity, was strongly associated with early PSA recurrence [both ERG+ and KPNA+, odds ratio: 22.2 (95% confidence interval, 6.0-82.3); ERG+ alone odds ratio: 17.9 (95% confidence interval, 5.1-63.5); P<0.0001 for both]. KPNA2 expression was significantly associated with the tumor stage (P<0.00001). The results suggest that the ERG+ phenotype might be selected in metastasis-initiating clones. ERG and KPNA2 may have a prognostic value, and their positivity in PC might warrant more aggressive treatments.

Clonal evaluation of early onset prostate cancer by expression profiling of ERG, SPINK1, ETV1, and ETV4 on whole-mount radical prostatectomy tissue.

BACKGROUND: Expression profiles of erythroblast transformation-specific (ETS)-related gene fusions and serine protease inhibitor Kazal-type 1 (SPINK1) in early onset prostate cancer have not been thoroughly explored. METHODS: We retrieved 151 radical prostatectomy specimens from young men with prostate cancer (<55 years) and characterized the expression of ETS-related gene (ERG), SPINK1, ETS Variant 1 (ETV1), and ETV4 by dual immunohistochemistry and dual RNA in situ hybridization. Age, race, family history, preoperative prostate-specific antigen, biochemical recurrence, and pathological variables using whole-mount radical prostatectomy tissue were collected. RESULTS: A total of 313 tumor nodules from 151 men including 68 (45%) Caucasians and 61 (40%) African Americans were included in the analysis. Positive family history of prostate cancer was seen in 65 (43%) patients. Preoperative prostate-specific antigen ranged from 0.3 to 52.7 ng/mL (mean = 7.04). The follow-up period ranged from 1 to 123.7 months (mean = 30.3). Biochemical recurrence was encountered in 8 of 151 (5%). ERG overexpression was observed in 85 of 151 (56%) cases, followed by SPINK1 in 61 of 151 (40%), ETV1 in 9 of 149 (6%), and ETV4 in 4 of 141 (3%). There were 25 of 151 (17%) cases showing both ERG and SPINK1 overexpression within different regions of either the same tumor focus or different foci. Higher frequency of ERG overexpression was seen in younger patients (≤45 years old; 76% vs 49%, P = .002), Caucasian men (71% vs 41% P = .0007), organ-confined tumors (64% vs 33%, P = .0008), and tumors of Gleason Grade groups 1 and 2 (62% vs 26%, P = .009). SPINK1 overexpression was more in African American men (68% vs 26%, P = .00008), in tumors with high tumor volume (>20%) and with anterior located tumors. ETV1 and ETV4 demonstrated rare overexpression in these tumors, particularly in the higher-grade tumors. CONCLUSION: This study expands the knowledge of the clonal evolution of multifocal cancer in young patients and support differences in relation to racial background and genetics of prostate cancer.

Claudin-1 upregulation is associated with favorable tumor features and a reduced risk for biochemical recurrence in ERG-positive prostate cancer.

BACKGROUND: Claudin-1 is a membrane-tight junction protein and important for the sealing of the paracellular cleft in epithelial and endothelial cells. Differential expression of Claudin-1 is linked to disease outcome in various cancers. MATERIAL AND METHODS: To evaluate the potential relevance of Claudin-1 expression in prostate cancer, a tissue microarray containing samples of 17,747 tumors with annotated clinico-pathological and molecular data was immunohistochemically analyzed for Claudin-1 expression. RESULTS: In normal prostate, glandular cells were always Claudin-1-negative while there was a strong staining of gland-surrounding basal cells. In contrast to normal prostatic glands, a positive Claudin-1 immunostaining, was found, however, in 38.7% of 12,441 interpretable cancers and was considered weak in 12.7%, moderate in 13.2%, and strong in 12.8% of cases. Positive Claudin-1 immunostaining was associated with favorable tumor features like low pT (p = 0.0032), low Gleason grade (p< 0.0001), and a reduced risk of PSA recurrence (p = 0.0005). A positive Claudin-1 staining was markedly more frequent in ERG-positive (63%) than in ERG-negative cancers (23%; p < 0.0001). Subset analyses revealed that all associations of Claudin-1 expression and favorable phenotype and prognosis were driven by ERG-positive cancers. Multivariate analyses revealed, however, that even in ERG-positive cancers, the prognostic impact of high Claudin-1 expression was not independent of established clinico-pathological parameters. Comparison with 12 previously analyzed chromosomal deletions identified conspicuous associations with PTEN and 12p13 deletions potentially indicating functional interactions. CONCLUSION: These data identify a peculiar role for Claudin-1 in prostate cancer. The protein is overexpressed in a fraction of prostate cancers and increased Claudin-1 expression levels predict a favorable prognosis in ERG-positive cancer.

Immunohistochemical expression of mismatch repair proteins (MSH2, MSH6, MLH1, and PMS2) in prostate cancer: correlation with grade groups (WHO 2016) and ERG and PTEN status.

The role of DNA MMR genes in prostate cancer (PrCa) is controversial, as genetic alterations leading to microsatellite instability are incompletely defined in these tumors. ERG rearrangements and PTEN loss are concomitant events in PrCa. The aim of this study has been to analyze the immunohistochemical (IHC) expression of MSH2, MSH6, MLH1, PMS2, ERG, and PTEN and their potential association with the grade group (GG) grading system (WHO 2016) and PSA recurrence in a series of 200 PrCa (PSMAR-Biobank, Barcelona, Spain). MSH2, MLH1, PMS2, and PTEN losses were documented in 8%, 5%, 2%, and 36.5%, respectively. ERG expression was found in 48%. MSH6 showed an increase of expression with respect to basal levels in 42.1% of the cases. A statistical association between MSH6 overexpression and GG5 was found (p = 0.0281). ERG-wild-type cases were associated with single MSH2 loss (p = 0.024), and MSH2 and/or MLH1 loss (p = 0.019). The percentage of cases with PTEN loss was 20.5% (8/39) in GG1, 37.6% (53/141) of clustered GG2 to 4, and 60% (12/20) of GG5 (chi-square test, p = 0.01). Thus, PTEN expression loss was statistically more frequent in the upper-grade tumors. PMS2 loss was an infrequent event, but it was statistically associated with shorter time to PSA recurrence (p = 0.011). These results suggest the existence of an alternative non-ERG pathway associated with MSH2 or MLH1 expression loss. MSH6 overexpression could be a marker of aggressiveness in PrCa. The IHC assessment of DNA MMR proteins, ERG and PTEN, could identify different altered PrCa pathways, which could aid patient stratification.

The expression profile and heterogeneity analysis of ERG in 633 consecutive prostate cancers from a single center.

BACKGROUND: Overexpression of ERG protein resulting from TMPRSS2:ERG rearrangement is highly specific for prostate cancer (PCa). However, the biological function of this fusion protein and its relationship with clinicopathological features still remain controversial. METHOD: In this study, we evaluated ERG protein expression/gene rearrangement and heterogeneity by immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) in a cohort of 633 consecutive PCa initially diagnosed by core-needle biopsy in the West China Hospital. RESULT: Overall, ERG protein expression was detected in 16.7% (106 of 633) cases, and frequently observed in PCa patients less than 60 years of age (31.9% vs 15.5%, P = 0.004) and in PCa with Gleason score less than 8 (20.0% vs 13.4%, P = 0.027), but infrequently observed in cases with intraductal carcinoma of the prostate (IDC-P) (10.0% vs 18.6%, P = 0.012). Follow-up analysis found that patients who progressed to castration-resistant prostate cancer (CRPC) have a lower frequency of ERG protein expression at initial biopsies compared to androgen deprivation therapy (ADT)-sensitive cases (14.1% vs 23.5%, P = 0.042), but Kaplan-Meier curve showed that ERG protein expression was not an independent prognostic marker. Of all the 106 ERG-positive cases, eight cases (7.5%) exhibited heterogeneous expression of ERG protein, in which ERG was only positive in tumors with Gleason pattern 3, but negative in Gleason pattern 4. The FISH analysis was consistent with IHC in six of these cases. In the other two cases, ERG rearrangement was detected in tumors with both Gleason pattern 3 and 4 by FISH, despite the negative protein expression in Gleason pattern 4. In case 1, a repeated biopsy was performed when the disease progressed to CRPC, and no ERG-positive cells were identified neither by IHC nor FISH. CONCLUSION: This was by far the largest series of ERG expression and heterogeneity analysis in Chinese PCa. The ERG rearrangement seemed to be frequently expressed in patients with relatively younger age and lower Gleason score and infrequently expressed in PCa with the IDC-P. PCa with positive ERG were less frequently to progress to CRPC, but there was no prognostic significance of ERG expression. In heterogeneous cases, ERG protein was detectable only in tumors with Gleason pattern 3 but not in pattern 4. Tumor cells with positive ERG expression/rearrangement seemed easily response to ADT.

Differential response to neoadjuvant hormonal therapy in prostate cancer: Predictive morphological parameters and molecular markers.

OBJECTIVES: The predictive value of the histological parameters and molecular markers for neoadjuvant hormonal therapy (NHT) in prostate cancer (PCa) has not been well established. The aim of this study is to determine pathological variables that can predict differences in response to NHT in PCa. METHODS: A total of 85 locally high risk PCa patients with matched preoperative needle biopsies and radical prostatectomy (RP) specimens were included. All patients were treated with NHT for at least 3 months. We quantified the response to NHT using a new proposed pathological grading system. The system classified tumors into five groups (grades 0-4) according to the severity of histological response. We then categorized the PCa patients into drug-sensitive (DS) group (Grades 2-4) and drug-resistant (DR) group (Grades 0-1). Two pathologists assessed each pretreated tumors for presence or absence of nine morphological features. The expression of androgen receptor (AR), ERG, and PTEN were evaluated by immunohistochemistry (IHC) as well. Statistical analysis was performed to identify significant associations between differentially histological response to NHT and morphological features as well as molecular aberrations. We evaluated different prediction models using receiver operating characteristic (ROC) curves and area under the ROC curve (AUC) analysis. RESULTS: 73% (n = 62/85) of tumors in our cohort belonged to DS group, whereas 27% (n = 23/85) of tumors were DR. Univariate logistic analysis suggested four pathological variables, cribriform growth pattern, macronucleoli, ductal adenocarcinoma differentiation, and PTEN loss in needle biopsies were significantly associated with DR effect, all with P-value < 0.05. Multivariate logistic regression analysis revealed that the three parameters as significant predictive factors for predicting DR effect. These were macronucleoli (RR = 4.008, P = 0.002), ductal adenocarcinoma differentiation (RR = 11.659, P = 0.009) and PTEN loss expression (RR = 7.275, P = 0.015). The AUC of three integrated indicators model was 0.781. CONCLUSIONS: Our study suggested that the presence of tumor cribriform growth pattern, macronucleoli, ductal adenocarcinoma differentiation, and PTEN loss in needle biopsies are of value in predicting tumor response to NHT regimen. Multivariate logistic regression analysis revealed the performance of combined pathological indicators in predicting DR response was better than that of model based on individual factor alone.

ERG oncoprotein expression in prostatic acinar adenocarcinoma; clinicopathologic significance.

OBJECTIVES: T/E fusion results in constitutive expression of ERG oncoprotein resulting in enhanced proliferation and invasive potential of prostatic cancer cells. In the present study we aimed to evaluate the ERG overexpression in 78 cases prostate acinar adenocarcinoma and its association with other prognostic parameters. RESULTS: ERG protein expression was noted in 39.7% (31 cases), out of which 3 cases (3.8%) showed low ERG expression, 10 cases (12.8%) showed intermediate expression and 18 cases (23.1%) revealed high ERG expression. Significant association of ERG expression was noted with gleason score (p = 0.009), WHO grade group (p = 0.008) and perineural invasion (p = 0.043). We found a significant proportion of our patients of prostatic acinar adenocarcinoma to over-express ERG protein which can help in devising therapeutic protocols. Significant association of ERG protein expression with gleason score and perineural invasion signifies its prognostic significance in prostatic carcinoma. Moreover, we also suggest that molecular studies should be performed in patients with prostatic carcinoma to look for T/E fusion gene and its correlation with ERG protein expression.

Clinical significance and EZH2, ERG and SPINK1 protein expression in pure and mixed ductal adenocarcinoma of the prostate.

BACKGROUND: Although ERG and SPINK1 molecular alterations have been studied in acinar and ductal adenocarcinoma of the prostate, EZH2 expression has not been previously evaluated in ductal adenocarcinoma. METHODS: We collected cases of pure and mixed ductal adenocarcinoma of the prostate and evaluated clinical significance and EZH2, ERG, and SPINK1 protein expression. RESULTS: We investigated 61 ductal adenocarcinomas, 22 pure and 39 mixed ductal/acinar. Except for tumor growth pattern, none of the clinical parameters studied significantly differed between pure and mixed tumors. Thirty-five percent of ductal adenocarcinomas were organ confined, 15% displayed seminal vesicle invasion. Lymph node and distal metastasis occurred in 13% and 24% of cases, respectively; 34% of patients experienced biochemical failure, 7% died of disease. Ninety-eight percent of tumors expressed EZH2; in 80% of cases >50% of tumor cells were positive. ERG and SPINK1 were expressed in 20% and 36% of cases, respectively. There was no difference in protein expression between pure and mixed ductal adenocarcinomas. ERG expression tended to be lower, and SPINK1 higher than reported for acinar tumors. Biochemical failure, metastasis and death did not differ between EZH2, ERG, and SPINK1 positive and negative patients, nor between <50% versus >50% expression of SPINK1 and EZH2, respectively. CONCLUSIONS: Pure and mixed ductal adenocarcinomas have similar clinical behavior and molecular alterations. Higher EZH2 and SPINK1 protein expression, compared to acinar prostatic adenocarcinoma, might account for the more aggressive clinical course of ductal adenocarcinoma.

Comparison of ERG and SPINK1 expression among incidental and metastatic prostate cancer in Japanese men.

BACKGROUND: TMPRSS2:ERG fusion is the most common genetic event in prostate cancer (PCa). However, its association with prognosis is controversial. Overexpression of serine protease inhibitor Kazal-type 1 (SPINK1) was almost exclusively defined in ERG-negative PCa in most studies. This study aimed to determine the association between ERG and SPINK1 expression and the biological aggressiveness of PCa by analyzing their expression in incidental and metastatic cohorts. METHODS: A total of 143 cystoprostatectomy specimens of invasive bladder cancer and 98 biopsy specimens from de novo metastatic PCa were analyzed. The prostate gland of cystoprostatectomy specimens was fixed and sliced in step sections. Immunohistochemistry of ERG and SPINK1 was conducted, and the results were correlated with the clinicopathological characteristics of the patients. RESULTS: The overall prevalence of incidental cancer was 32.2% (46/143). The frequencies of both ERG and SPINK1 expression were not significantly different between incidental and metastatic cohorts (15.2% and 14.3%; P = 1.00, and 6.5% and 12.2%; P = 0.38, respectively). In the metastatic cohort, any pre-treatment factors were not significantly associated with the frequencies of ERG and SPINK1 expression. However, SPINK1 expression was significantly associated with a shorter time to castration-resistant PCa (CRPC) (P = 0.048). Meanwhile, overall survival was not significantly associated with the expression status of ERG and SPINK1 (P = 0.71). CONCLUSIONS: ERG and SPINK1 expression may not have significant influence on the metastatic behavior of PCa. SPINK1 expression was significantly associated with a shorter time to CRPC in metastatic PCa. The expression profile of ERG and SPINK1 may be a useful predictor for effect of androgen deprivation therapy in patients with metastatic castration-sensitive PCa.

Heterogenous expression of ERG oncoprotein in Malaysian men with adenocarcinoma of the prostate.

INTRODUCTION: Prostate cancer is a heterogenous disease and the mechanisms that drive it to behave differently are not well understood. Tumour expression of the ERG oncogene occurs in the majority of patients with prostate cancer in Western studies. This is considered to be oncogenic as ERG acts as a transcription factor to regulate genes involved in tumour proliferation and invasion. In this study we investigated expression of ERG in Malaysian men with prostate cancer. METHODS: Tissues were collected from 80 patients with clinically detected prostate cancer and treated with radical prostatectomy. Cases were tested for ERG by immunohistochemistry using the mouse monoclonal antibody EP111. All blocks on 48 cases were tested in order to determine the extent of heterogeneity of ERG expression within individual cases. ERG expression was analysed in relation to patient age, ethnicity and tumour stage and grade. RESULTS: Forty-six percent of cases were ERG positive. There was no significant association between ERG and tumour grade or stage. Sixty-nine percent of Indian patients had ERG positive tumours; this was significantly higher (p=0.031) than for Chinese (40%) and Malay (44%) patients. Heterogeneity of ERG expression, in which both positive and negative clones were present, was seen in 35% of evaluated cases. Evaluation by tumour foci showed younger patients had more ERG positive tumour foci than older patients (p=0.01). Indian patients were more likely to have the majority of tumour foci with ERG staining positively, compared to either Chinese or Malay patients (P <0.01). CONCLUSION: In this study, tumour expression of ERG was more likely to occur in patients of Indian ethnicity.

Clinical utility of assessing PTEN and ERG protein expression in prostate cancer patients: a proposed method for risk stratification.

OBJECTIVES: To assess the prognostic value of ERG and PTEN protein expression as two of the most common genetic aberration in men with prostate cancer managed non-surgically by androgen deprivation therapy (ADT). MATERIALS AND METHODS: 463 tumor samples were assessed by double immunohistochemistry stains for ERG and PTEN and data correlated with clinical pathological features including, Gleason score, patients' outcome and ADT. RESULTS: ERG expression and PTEN protein loss were present in 28.2% and 38% of total patients respectively. There was a significant interplay between ERG and PTEN expression with 21.8% PTEN negative tumors being ERG positive (p < 0.001). Both ERG and PTEN showed significant association with lethal disease in all patients and those treated with prior ADT representing castrate-resistant disease. However, only PTEN remained significant in multivariable proportional hazards regression analysis, when including Gleason score and patients' age. Depending on patient's subgroup, intact positive PTEN intensity showed better cancer-specific survival with HR ranging from 0.25 to 0.4 compared to tumors with loss of PTEN expression. Assessing combined marker status, patients with decreased PTEN intensity without ERG positivity showed the worst clinical outcome compared to those with no PTEN loss and no ERG expression, where they had best clinical outcome. Patients with ERG expression with or without PTEN loss showed intermediate risk in relation to lethal disease. CONCLUSION: This study confirms a significant prognostic role for assessing ERG and PTEN in men with prostate cancer. It supports a role for utilizing combined ERG/PTEN status clinically and prospectively for stratifying PCa patients into different prognostic groups.

The Significance of ERG and Androgen Receptor Expression in Adenocarcinoma Prostate.

Background Fusions of transmembrane protease, serine 2 (TMPRSS2) with erythroblast transformation specific transcription factors have been found in prostate cancer. The v-etserythroblastosis virus E26 oncogene homologue (ERG) is a proto-oncogene of the erythroblast transformation specific transcription factor family. TMPRSS2-ERG fusion is the most common molecular alteration present in about 50% of prostatic adenocarcinomas. Androgen receptor (AR) plays a key role in prostate development and is involved in the progression of prostate cancer. Objective To evaluate the significance of combined ERG and AR expression in cases of prostatic adenocarcinoma. Method The study was conducted at Dr. Ram Manohar Lohia Institute of Medical Sciences, Lucknow, Uttar Pradesh, India. Formalin fixed-paraffin embedded archival prostatic tissue specimens were obtained. A total of 10 cases of prostatic adenocarcinoma were included in the study. Immunohistochemistry for Androgen receptor was done by the standard protocol. Multiplex immunohistochemical staining was done for ERG+CK5 using a primary antibody cocktail of mouse and rabbit antibodies. Result Specific AR immunostaining was exclusively nuclear and was present in all 10 cases in varying intensity. Specific ERG immunostaining was nuclear and was present in seven cases (70%) and absent in three cases (30%). The three cases that were negative for ERG had a Gleason score of ≤ 6 and the AR staining was strong and present in about 90% of the cells. Gleason score was directly related to the ERG staining while AR staining was inversely related to the ERG staining. Conclusion The prognostic value of combined ERG and AR over-expression, its associated genes should be further investigated as potential therapeutic targets in prostate cancer progression. Preliminary data is being presented. Larger prospective studies with survival analysis are essential for prognostic significance.

MiR-1271 Inhibits Cell Growth in Prostate Cancer by Targeting ERG.

ETS-related gene (ERG) is an oncogene that is commonly found in prostate cancer (PCa). Several miRNAs have been reported to be associated with PCa. This study was undertaken to identify miRNAs that act as a tumor suppressor by targeting ERG. We collected 70 PCa and paired adjacent non-tumor (Adjacent-N) tissues and analyzed ERG expression by immunohistochemistry(IHC). Expression of 6 miRNAs (miR-21,-34a,-96,-125b,-150 and miR-1271) was analyzed by qRT-PCR. Luciferase reporter assay was performed to examine miRNA binding to the 3'-UTR of target genes. The effects of ectopic expression of miRNA on cell growth and MAPK signaling pathway were investigated in in PC-3 and LNCaP cell lines. Among 70 PCa cases, 13 (18.6%) were ERG positive. No significant difference of miR-34a, 96, 125b, and 150 expression was found between PCa and Adjacent-N tissues. Significantly higher level of miR-21 and lower level of miR-1271 expression were found in cancer tissues. Furthermore, miR-1271 was down-regulated in ERG-positive PCa cases (p < 0.05). Based on luciferase reporter assay, we identified ERG gene as a direct target gene for miR-1271. Transfection of a miR-1271 mimics into PC-3 and LNCaP cells repressed the ERG expression and significantly suppressed cell growth. Lastly, ectopic expression of miR-1271 inhibits AKT1, p38gama and CREB kinase activity. Our results suggested that reduced expression of miR-1271 may be involved in the ERG expression and that miR-1271 could be a therapeutic target for ERG-positive prostate cancer patients.

Loss of FOXO1 Cooperates with TMPRSS2-ERG Overexpression to Promote Prostate Tumorigenesis and Cell Invasion.

E26 transformation-specific transcription factor ERG is aberrantly overexpressed in approximately 50% of all human prostate cancer due to TMPRSS2-ERG gene rearrangements. However, mice with prostate-specific transgenic expression of prostate cancer-associated ERG alone fail to develop prostate cancer, highlighting that ERG requires other lesions to drive prostate tumorigenesis. Forkhead box (FOXO) transcription factor FOXO1 is a tumor suppressor that is frequently inactivated in human prostate cancer. Here, we demonstrate that FOXO1, but not other FOXO proteins (FOXO3 and FOXO4), binds and inhibits the transcriptional activity of prostate cancer-associated ERG independently of FOXO1 transcriptional activity. Knockdown of endogenous FOXO1 increased invasion of TMPRSS2-ERG fusion-positive VCaP cells, an effect completely abolished by ERG knockdown. Patient specimen analysis demonstrated that FOXO1 and ERG protein expression inversely correlated in a subset of human prostate cancer. Although human ERG transgene expression or homozygous deletion of Foxo1 alone in the mouse prostate failed to promote tumorigenesis, concomitant ERG transgene expression and Foxo1 deletion resulted in upregulation of ERG target genes, increased cell proliferation, and formation of high-grade prostatic intraepithelial neoplasia. Overall, we provide biochemical and genetic evidence that aberrantly activated ERG cooperates with FOXO1 deficiency to promote prostate tumorigenesis and cell invasion. Our findings enhance understanding of prostate cancer etiology and suggest that the FOXO1-ERG signaling axis can be a potential target for treatment of prostate cancer. Cancer Res; 77(23); 6524-37. ©2017 AACR.

Proteinase-Activated Receptor-2 Modulates Ve-Cadherin Expression to Affect Human Vascular Endothelial Barrier Function.

Published data indicate that the protease-activated receptor (PAR) 2 is involved in the pathogenesis of some cardiovascular diseases; the underlying mechanism is to be further investigated. Ve-cadherin is a critical molecule in maintaining the endothelial barrier integrity. This study aims to investigate the role of PAR2 activation in compromising the cardiac endothelial barrier function. In this study, human umbilical vein endothelial cells (Huvec cells) were cultured into monolayers using as an in vitro model of barrier function. The transepithelial electric resistance (TER) and permeability to dextran were assessed as indicators of barrier function. The expression of Ve-cadherin in Huvec cells was assessed by real-time RT-PCR, Western blotting, and chromatin immunoprecipitation. The results showed that exposure to tryptase in the culture, the barrier function of the Huvec monolayers, was markedly compromised; the levels of Ve-cadherin, one of the tight junction proteins, were suppressed as well. This was mimicked by exposing Huvec monolayers to the active PAR2 peptides (PAR2AP). After exposing to PAR2AP, the levels of histone deacetylase (HDAC)11 were increased in the Huvec cells. HDAC11 formed a complex with the transcription factor of Ve-cadherin to attenuate the Erg gene transcription activities and suppressed the expression of Ve-cadherin. In conclusion, activation of PAR2 compromises the vascular endothelial barrier function by suppressing the expression of Ve-cadherin. J. Cell. Biochem. 118: 4587-4593, 2017. © 2017 Wiley Periodicals, Inc.

Circulating Antioxidant Levels and Risk of Prostate Cancer by TMPRSS2:ERG.

BACKGROUND: Few studies have considered etiological differences across molecular subtypes of prostate cancer, despite potential to improve opportunities for precision prevention of a disease for which modifiable risk factors have remained elusive. Factors that lead to DNA double-strand breaks, such as oxidative stress, may promote the formation of the TMPRSS2:ERG gene fusion in prostate cancer. We tested the hypothesis that increasing levels of pre-diagnostic circulating antioxidants, which may reduce oxidative stress, are associated with lower risk of developing TMPRSS2:ERG positive prostate cancer. METHODS: We conducted a nested case-control study, including 370 cases and 2,470 controls, to evaluate associations between pre-diagnostic α- and ß-carotene, α- and γ-tocopherol, ß-cryptoxanthin, lutein, lycopene, retinol, and selenium with the risk of prostate cancer by ERG protein expression status (a marker of TMPRSS2:ERG). Multivariable unconditional polytomous logistic regression was used to calculate odds ratios and 95% confidence intervals. RESULTS: We did not find any of the antioxidants to be significantly associated with the risk of prostate cancer according to ERG status. CONCLUSIONS: The results do not support the hypothesis that circulating pre-diagnostic antioxidant levels protect against developing TMPRSS2:ERG positive prostate cancer. Additional studies are needed to explore mechanisms for the development of TMPRSS2:ERG positive disease. Prostate 77: 647-653, 2017. © 2017 Wiley Periodicals, Inc.

miR-145 suppresses colorectal cancer cell migration and invasion by targeting an ETS-related gene.

MicroRNA-45 (miR-145) has been demonstrated to be downregulated in various cancer types including colorectal cancer (CRC). However, the function of miR­145 in CRC has not been clearly elucidated. In this study, we examined miR-145 expression by quantitative real­time PCR (qRT­PCR) in CRC cell lines as well as tumors and corresponding normal mucosa, and the results were correlated to the clinicopathological parameters. In addition, using computational algorithms we investigated putative miR­145 targets. The role of miR­145 was further examined in studies in vitro. In our study miR­145 was significantly decreased in CRC tissues and cell lines compared with non­cancerous colorectal mucosa, especially lymph node or distance metastasis cases. Based on computational algorithms, we assumed that ERG was directly modulated by miR­145 in colorectal cancer cells. For the first time, we demonstrated that ERG was highly expressed in CRC tissues compared with normal ones by qRT­PCR. The inverse correlation between the expression of miR­145 and ERG was observed in CRC tissues. Dual­Luciferase assays demonstrated the direct interaction between miR­145 and 3'­UTR of ERG mRNA. Ectopic expression of miR­145 suppressed the proliferation and invasion ability of colorectal cancer cells, while ERG knockdown partially restored the tumor suppressive effect of miR­145. These results suggested that miR­145 might act as a tumor suppressor during the process of CRC malignant transformation by interacting with ERG.

High alpha-methylacyl-CoA racemase (AMACR) is associated with ERG expression and with adverse clinical outcome in patients with localized prostate cancer.

Alpha-methylacyl-CoA racemase (AMACR) is a well-characterized marker extensively utilized in prostate cancer (PCA) diagnosis. However, the prognostic value of AMACR expression and its relation to TMPRSS2-ERG gene rearrangement as one of the most common molecular alterations in PCA is not fully explored. AMACR expression was investigated in a cohort of 218 men with localized PCA treated by radical prostatectomy and correlated with ERG and various clinical and pathological parameters. In vitro studies assessed AMACR changes to ERG knockdown and other related genes. In addition, bioinformatics validated the significance of AMACR/ERG expression and assessed relevant genetic signatures in relation to AMACR/ERG expression. AMACR expression was significantly associated with disease progression and with ERG (p ∼0). Seventeen percent of cancer foci showed negative/weak AMACR expression while being ERG positive. High AMACR expression was significantly associated with positive surgical margins (p = 0.01), specifically in tumors with lower Gleason score <7, with ∼95 % exhibiting positive surgical margin (p = 0.008). High AMACR showed marginal association with PSA biochemical recurrence (BCR) (p = 0.06) which was slightly more pronounced in ERG-positive tumors (p = 0.04). This was validated in other public cohorts. However, in this cohort, the association with BCR was not statistically significant in multivariate analysis (p = 0.09). Using in vitro cellular models, AMACR messenger RNA (mRNA) expression, but not protein levels, showed an association with ERG expression. We report for the first time a significant association between AMACR and ERG with prognostic implication. Patients with high AMACR/ERG-positive PCA may be at higher risk for disease progression, and additional studies in larger cohorts are needed to confirm the above findings. Functional studies investigating the molecular pathways connecting AMACR and ERG may provide an additional insight into PCA progression pathways.