Trefoil factor 3 overexpression in prostatic carcinoma: prognostic importance using tissue microarrays

Potentials and future perspectives of multi-target drugs in cancer treatment: the next generation anti-cancer agents

Cancer is a major public health problem worldwide with more than an estimated 19.3 million new cases in 2020. The occurrence rises dramatically with age, and the overall risk accumulation is combined with the tendency for cellular repair mechanisms to be less effective in older individuals. Conventional cancer treatments, such as radiotherapy, surgery, and chemotherapy, have been used for decades to combat cancer. However, the emergence of novel fields of cancer research has led to the exploration of innovative treatment approaches focused on immunotherapy, epigenetic therapy, targeted therapy, multi-omics, and also multi-target therapy. The hypothesis was based on that drugs designed to act against individual targets cannot usually battle multigenic diseases like cancer. Multi-target therapies, either in combination or sequential order, have been recommended to combat acquired and intrinsic resistance to anti-cancer treatments. Several studies focused on multi-targeting treatments due to their advantages include; overcoming clonal heterogeneity, lower risk of multi-drug resistance (MDR), decreased drug toxicity, and thereby lower side effects. In this study, we'll discuss about multi-target drugs, their benefits in improving cancer treatments, and recent advances in the field of multi-targeted drugs. Also, we will study the research that performed clinical trials using multi-target therapeutic agents for cancer treatment.

PTEN, ERG, SPINK1, and TFF3 Status and Relationship in a Prostate Cancer Cohort from Jordanian Arab Population

Background and Objectives: Prognostic biomarkers in prostate cancer (PCa) include PTEN, ERG, SPINK1, and TFF3. Their relationships and patterns of expression in PCa in developing countries, including Jordan, have not yet been investigated. Materials and Methods: A tissue microarray (TMA) of PCa patients was taken from paraffin-embedded tissue blocks for 130 patients. PTEN, ERG, SPINK1, and TFF3 expression profiles were examined using immunohistochemistry (IHC) and correlated with each other and other clinicopathological factors. Results: PTEN loss of any degree was observed in 42.9% of PCa cases. ERG and TFF3 were expressed in 59.3% and 46.5% of PCa cases, respectively. SPINK1 expression was observed in 6 out of 104 PCa cases (5.4%). Among all PCa cases (n = 104), 3.8% (n = 4) showed SPINK1+/ERG+ phenotype, 1.9% (n = 2) showed SPINK1+/ERG- phenotype, 56.7% (n = 59) showed SPINK1-/ERG+ phenotype, and 37.5% showed SPINK1-/ERG- phenotype (n = 39). Among ERG positive cases (n = 63), 6.3% were SPINK1 positive. Among SPINK1 positive cases (n = 6), 66.7% were ERG positive. SPINK1 expression was predominantly observed in a subgroup of cancers that expressed TFF3 (6/6). Additionally, a statistically significant loss of PTEN expression was observed from Gleason Score 6 (GS6) (Grade Group 1 (GG1)) to GS9-10 (GG5); (p-value 0.019). Conclusions: This is the first study to look at the status of the PTEN, ERG, SPINK1, and TFF3 genes in a Jordanian Arab population. Loss of PTEN has been linked to more aggressive prostate cancer with high GSs/GGs. SPINK1 expression was predominantly observed in a subgroup of cancers that expressed TFF3. Our results call for screening these biomarkers for grading and molecular subtyping of the disease.

Mitochondrial Alterations in Prostate Cancer: Roles in Pathobiology and Racial Disparities

Prostate cancer (PCa) affects millions of men worldwide and is a major cause of cancer-related mortality. Race-associated PCa health disparities are also common and are of both social and clinical concern. Most PCa is diagnosed early due to PSA-based screening, but it fails to discern between indolent and aggressive PCa. Androgen or androgen receptor-targeted therapies are standard care of treatment for locally advanced and metastatic disease, but therapy resistance is common. Mitochondria, the powerhouse of cells, are unique subcellular organelles that have their own genome. A large majority of mitochondrial proteins are, however, nuclear-encoded and imported after cytoplasmic translation. Mitochondrial alterations are common in cancer, including PCa, leading to their altered functions. Aberrant mitochondrial function affects nuclear gene expression in retrograde signaling and promotes tumor-supportive stromal remodeling. In this article, we discuss mitochondrial alterations that have been reported in PCa and review the literature related to their roles in PCa pathobiology, therapy resistance, and racial disparities. We also discuss the translational potential of mitochondrial alterations as prognostic biomarkers and as effective targets for PCa therapy.

Presence of cells in the polyaneuploid cancer cell (PACC) state predicts the risk of recurrence in prostate cancer

BACKGROUND

The nonproliferating polyaneuploid cancer cell (PACC) state is associated with therapeutic resistance in cancer. A subset of cancer cells enters the PACC state by polyploidization and acts as cancer stem cells by undergoing depolyploidization and repopulating the tumor cell population after the therapeutic stress is relieved. Our aim was to systematically assess the presence and importance of this entity in men who underwent radical prostatectomy with curative intent to treat their presumed localized prostate cancer (PCa).

MATERIALS AND METHODS

Men with National Comprehensive Cancer Network intermediate- or high-risk PCa who underwent radical prostatectomy l from 2007 to 2015 and who did not receive neoadjuvant treatment were included. From the cohort of 2159 patients, the analysis focused on a subcohort of 209 patients and 38 cases. Prostate tissue microarrays (TMAs) were prepared from formalin-fixed, paraffin-embedded blocks of the radical prostatectomy specimens. A total of 2807 tissue samples of matched normal/benign and cancer were arrayed in nine TMA blocks. The presence of PACCs and the number of PACCs on each core were noted.

RESULTS

The total number of cells in the PACC state and the total number of cores with PACCs were significantly correlated with increasing Gleason score (p = 0.0004) and increasing Cancer of the Prostate Risk Assessment Postsurgical (CAPRA-S) (p = 0.004), but no other variables. In univariate proportional hazards models of metastasis-free survival, year of surgery, Gleason score (9-10 vs. 7-8), pathology stage, CAPRA-S, total PACCs, and cores positive for PACCs were all statistically significant. The multivariable models with PACCs that gave the best fit included CAPRA-S. Adding either total PACCs or cores positive for PACCs to CAPRA-S both significantly improved model fit compared to CAPRA-S alone.

CONCLUSION

Our findings show that the number of PACCs and the number of cores positive for PACCs are statistically significant prognostic factors for metastasis-free survival, after adjusting for CAPRA-S, in a case-cohort of intermediate- or high-risk men who underwent radical prostatectomy. In addition, despite the small number of men with complete data to evaluate time to metastatic castration-resistant PCa (mCRPC), the total number of PACCs was a statistically significant predictor of mCRPC in univariate analysis and suggested a prognostic effect even after adjusting for CAPRA-S.

Diagnostic and prognostic role of TFF3, Romo-1, NF-кB and SFRP4 as biomarkers for endometrial and ovarian cancers: a prospective observational translational study

Purpose

This study aimed to evaluate trefoil factor 3 (TFF3), secreted frizzled-related protein 4 (sFRP4), reactive oxygen species modulator 1 (Romo1) and nuclear factor kappa B (NF-κB) as diagnostic and prognostic markers of endometrial cancer (EC) and ovarian cancer (OC).

Methods

Thirty-one patients with EC and 30 patients with OC undergone surgical treatment were enrolled together with 30 healthy controls in a prospective study. Commercial ELISA kits determined serum TFF-3, Romo-1, NF-кB and sFRP-4 concentrations.

Results

Serum TFF-3, Romo-1 and NF-кB levels were significantly higher in patients with EC and OC than those without cancer. Regarding EC, none of the serum biomarkers differs significantly between endometrial and non-endometrioid endometrial carcinomas. Mean serum TFF-3 and NF-кB levels were significantly higher in advanced stages. Increased serum levels of TFF-3 and NF-кB were found in those with a higher grade of the disease. Regarding OC, none of the serum biomarkers differed significantly among histological subtypes. Significantly increased serum levels of NF-кB were observed in patients with advanced-stage OC than those with stage I and II diseases. No difference in serum biomarker levels was found between those who had a recurrence and those who had not. The sensibility and specificity of these four biomarkers in discriminating EC and OC from the control group showed encouraging values, although no one reached 70%.

Conclusions

TFF-3, Romo-1, NF-кB and SFRP4 could represent new diagnostic and prognostic markers for OC and EC. Further studies are needed to validate our results.

The Movember Global Action Plan 1 (GAP1): Unique Prostate Cancer Tissue Microarray Resource

BACKGROUND

The need to better understand the molecular underpinnings of the heterogeneous outcomes of patients with prostate cancer is a pressing global problem and a key research priority for Movember. To address this, the Movember Global Action Plan 1 Unique tissue microarray (GAP1-UTMA) project constructed a set of unique and richly annotated tissue microarrays (TMA) from prostate cancer samples obtained from multiple institutions across several global locations.

METHODS

Three separate TMA sets were built that differ by purpose and disease state.

RESULTS

The intended use of TMA1 (Primary Matched LN) is to validate biomarkers that help determine which clinically localized prostate cancers with associated lymph node metastasis have a high risk of progression to lethal castration-resistant metastatic disease, and to compare molecular properties of high-risk index lesions within the prostate to regional lymph node metastases resected at the time of prostatectomy. TMA2 (Pre vs. Post ADT) was designed to address questions regarding risk of castration-resistant prostate cancer (CRPC) and response to suppression of the androgen receptor/androgen axis, and characterization of the castration-resistant phenotype. TMA3 (CRPC Met Heterogeneity)'s intended use is to assess the heterogeneity of molecular markers across different anatomic sites in lethal prostate cancer metastases.

CONCLUSIONS

The GAP1-UTMA project has succeeded in combining a large set of tissue specimens from 501 patients with prostate cancer with rich clinical annotation.

IMPACT

This resource is now available to the prostate cancer community as a tool for biomarker validation to address important unanswered clinical questions around disease progression and response to treatment.

Leveraging the CSF proteome toward minimally-invasive diagnostics surveillance of brain malignancies

Background

Diagnosis and prognostication of intra-axial brain tumors hinges on invasive brain sampling, which carries risk of morbidity. Minimally-invasive sampling of proximal fluids, also known as liquid biopsy, can mitigate this risk. Our objective was to identify diagnostic and prognostic cerebrospinal fluid (CSF) proteomic signatures in glioblastoma (GBM), brain metastases (BM), and primary central nervous system lymphoma (CNSL).

Methods

CSF samples were retrospectively retrieved from the Penn State Neuroscience Biorepository and profiled using shotgun proteomics. Proteomic signatures were identified using machine learning classifiers and survival analyses.

Results

Using 30 µL CSF volumes, we recovered 755 unique proteins across 73 samples. Proteomic-based classifiers identified malignancy with area under the receiver operating characteristic (AUROC) of 0.94 and distinguished between tumor entities with AUROC ≥0.95. More clinically relevant triplex classifiers, comprised of just three proteins, distinguished between tumor entities with AUROC of 0.75-0.89. Novel biomarkers were identified, including GAP43, TFF3 and CACNA2D2, and characterized using single cell RNA sequencing. Survival analyses validated previously implicated prognostic signatures, including blood-brain barrier disruption.

Conclusions

Reliable classification of intra-axial malignancies using low CSF volumes is feasible, allowing for longitudinal tumor surveillance.

Low expression of TFF3 in papillary thyroid carcinoma may correlate with poor prognosis but high immune cell infiltration

Background: Papillary thyroid carcinoma (PTC) is one of the most common endocrine malignancies and has a favorable prognosis. However, optimal treatments and prognostic markers have not been clearly identified. Methods: Gene expression data from primary PTC were downloaded from the Gene Expression Omnibus database and subjected to two analyses of differentially expressed genes (DEGs), followed by intersecting individual and integrated DEGs analyses as well as gene set enrichment analysis. Analysis of data from Sequence Read Archive and The Cancer Genome Atlas, immunohistochemistry and qRT-PCR of TFF3 were performed to validate the results. Finally, the relationship between gene expression and disease-free survival as well as immune cell infiltration were investigated. Results: Six critical DEGs and several tumor-enriched signaling pathways were identified. Immunohistochemistry and qRT-PCR validated the low expression of TFF3 in PTC. TFF3 and FCGBP are coexpressed in PTC, and patients with lower gene expression had worse disease-free survival but higher immune cell infiltration. Conclusion: TFF3 was significantly underexpressed and may function with FCGBP synergistically in PTC.

GSTP1 positive prostatic adenocarcinomas are more common in Black than White men in the United States

GSTP1 is a member of the Glutathione-S-transferase (GST) family silenced by CpG island DNA hypermethylation in 90-95% of prostate cancers. However, prostate cancers expressing GSTP1 have not been well characterized. We used immunohistochemistry against GSTP1 to examine 1673 primary prostatic adenocarcinomas on tissue microarrays (TMAs) with redundant sampling from the index tumor from prostatectomies. GSTP1 protein was positive in at least one TMA core in 7.7% of cases and in all TMA cores in 4.4% of cases. The percentage of adenocarcinomas from Black patients who had any GSTP1 positive TMA cores was 14.9%, which was 2.5 times higher than the percentage from White patients (5.9%; P < 0.001). Further, the percentages of tumors from Black patients who had all TMA spots positive for GSTP1 (9.5%) was 3-fold higher than the percentage from White patients (3.2%; P<0.001). In terms of association with other molecular alterations, GSTP1 positivity was enriched in ERG positive cancers among Black men. By in situ hybridization, GSTP1 mRNA expression was concordant with protein staining, supporting the lack of silencing of at least some GSTP1 alleles in GSTP1-positive tumor cells. This is the first report revealing that GSTP1-positive prostate cancers are substantially over-represented among prostate cancers from Black compared to White men. This observation should prompt additional studies to determine whether GSTP1 positive cases represent a distinct molecular subtype of prostate cancer and whether GSTP1 expression could provide a biological underpinning for the observed disparate outcomes for Black men.

HOXB13 and TFF3 can contribute to the prognostic stratification of prostate adenocarcinoma

Homeobox B13 (HOXB13) and trefoil factor 3 (TFF3) are novel candidates for the classification of prostate cancer (PC) in molecular subtypes that could predict the clinical evolution of patients. The aim of our study was to analyze the possible associations between HOXB13 and TFF3 immunohistochemical (IHC) expression in sporadic prostate adenocarcinoma (PAC), the potential prognostic value in relation to the classical clinico-pathological parameters, as well as their role in defining distinct molecular subtypes of this malignancy. The study group comprised 105 patients diagnosed with PAC who underwent radical prostatectomy. IHC exam was performed using anti-HOXB13 and anti-TFF3 antibodies and a scoring system that permit the separation of the cases into two subgroups, with low and high immunoexpression, respectively. The statistical analysis evaluated the relationship between the two immunomarkers and clinico-pathological parameters. The Kaplan-Meier curves and log-rank Mantel-Cox test were used for assessing the prostate-specific antigen (PSA)-progression free survival. Four subgroups of PAC were defined based on the IHC overexpression and low immunoexpression of HOXB13 and TFF3. High HOXB13 and TFF3 immunoexpression was commonly identified in cases characterized by a Gleason score over 7, a G4 or G5 dominant pattern, a grade group of 3 or 4 and a preoperatory PSA serum level over 20 ng/mL. HOXB13 overexpression was also associated with pathological tumor-node-metastasis (pTNM) stage. The subgroup with both low HOXB13 and TFF3 immunoexpression had the highest PSA-progression free interval, whereas the subgroup with high HOXB13 immunoexpression and low TFF3 immunoexpression presented the lowest rate, but no statistically significant differences were registered. Our results sustain the role of HOXB13 and TFF3 in the stratification of PAC. Further investigations in larger cohorts are imposed to validate the clinical significance of these subgroups in the diagnostic and prognostic of PAC.

TFF3 and TFF1 expression levels are elevated in colorectal cancer and promote the malignant behavior of colon cancer by activating the EMT process

Reports on the roles of the secreted trefoil factor (TFF)1 and 3 in colorectal cancer (CRC) and their underlying mechanisms of action in tumorigenesis are not common and are controversial. In the present study, the mRNA expression and promoter methylation of TFF1 and TFF3 in cancer and adjacent normal tissues were investigated, and their association with other clinical factors and patient prognosis were evaluated. Moreover, the association between TFF3 and epithelial mesenchymal transition (EMT) was explored by overexpressing or inhibiting TFF3 expression. The results revealed that the mRNA level of TFF1 and TFF3 in the cancer tissues was significantly higher than that in the matched adjacent normal tissues (P=0.034 and P=0.007, respectively), and a higher expression of TFF3, but not TFF1, was predominantly associated with clinicopathological factors and a poorer prognosis. No correlation was observed between promoter methylation and the expression of TFF1 or TFF3. The overexpression of TFF3 promoted the proliferation, migration and invasiveness of HT29 cells, and induced an increase in the expression of Twist1, Snail and Vimentin, while causing a decrease in E-cadherin expression. On the contrary, the knockdown of TFF3 resulted in opposite effects in the LoVo cells. On the whole, the findings of this study indicate that TFF3 may be a promising new factor for the estimation of the survival of patients with CRC, and may promote the malignant progression of CRC by activating the EMT process. Therefore, TFF3 may be a future potential therapeutic target for CRC.

Overexpression of TFF3 is involved in prostate carcinogenesis via blocking mitochondria-mediated apoptosis

The overexpression of trefoil factor family 3 (TFF3) is observed in a variety of cancers, including prostate cancer (PCa), and its potential role in carcinogenesis, such as activating the PI3K/AKT pathway, is suggested. However, its role and its related mechanisms in prostate tumorigenesis remain unknown. To elucidate the role of TFF3 overexpression in PCa, we silenced TFF3 in two PCa cell lines that overexpressed TFF3 and explored the molecular mechanism behind its antiapoptotic role. We also examined TFF3 expression in 108 Korean PCa specimens and 106 normal prostate tissues by immunohistochemistry (IHC) analysis. The mean TFF3 IHC score in the tumor tissues was significantly higher than that in the normal tissues (4.702 vs. 0.311, P = 2.52 × 10-24). TFF3-silenced cells showed suppressed tumor cell growth and migration. TFF3 silencing decreased BCL2 and increased BAX expression. The translocation of BAX to the mitochondria was also confirmed. After TFF3 silencing, the expression of the mitochondrial proapoptotic proteins, cytochrome C and Smac/DIABLO, was elevated, and these proteins were released from the mitochondria to the cytosol. Downstream mediators of mitochondrial apoptosis, including cleaved caspase-3, caspase-9, and PARP, were also elevated. Accordingly, the proportion of apoptotic cells was significantly higher among TFF3-silenced cells. There was no difference in extrinsic apoptosis-related molecules after TFF3 silencing. All the results support that TFF3 silencing induces the downstream signaling pathway of mitochondria-mediated apoptosis. This study provides a better understanding of the mechanism of prostate tumorigenesis, suggesting TFF3 as a potential biomarker and therapeutic target of PCa.

Comprehensive Evaluation of Programmed Death-Ligand 1 Expression in Primary and Metastatic Prostate Cancer

Antibodies targeting the programmed cell death protein 1/programmed death-ligand 1 (PD-L1) interaction have shown clinical activity in multiple cancer types. PD-L1 protein expression is a clinically validated predictive biomarker of response for such therapies. Prior studies evaluating the expression of PD-L1 in primary prostate cancers have reported highly variable rates of PD-L1 positivity. In addition, limited data exist on PD-L1 expression in metastatic castrate-resistant prostate cancer (mCRPC). Here, we determined PD-L1 protein expression by immunohistochemistry using a validated PD-L1-specific antibody (SP263) in a large and representative cohort of primary prostate cancers and prostate cancer metastases. The study included 539 primary prostate cancers comprising 508 acinar adenocarcinomas, 24 prostatic duct adenocarcinomas, 7 small-cell carcinomas, and a total of 57 cases of mCRPC. PD-L1 positivity was low in primary acinar adenocarcinoma, with only 7.7% of cases showing detectable PD-L1 staining. Increased levels of PD-L1 expression were noted in 42.9% of small-cell carcinomas. In mCRPC, 31.6% of cases showed PD-L1-specific immunoreactivity. In conclusion, in this comprehensive evaluation of PD-L1 expression in prostate cancer, PD-L1 expression is rare in primary prostate cancers, but increased rates of PD-L1 positivity were observed in mCRPC. These results will be important for the future clinical development of programmed cell death protein 1/PD-L1-targeting therapies in prostate cancer.

MYC drives overexpression of telomerase RNA (hTR/TERC) in prostate cancer

Telomerase consists of at least two essential elements, an RNA component hTR or TERC that contains the template for telomere DNA addition and a catalytic reverse transcriptase (TERT). While expression of TERT has been considered the key rate-limiting component for telomerase activity, increasing evidence suggests an important role for the regulation of TERC in telomere maintenance and perhaps other functions in human cancer. By using three orthogonal methods including RNAseq, RT-qPCR, and an analytically validated chromogenic RNA in situ hybridization assay, we report consistent overexpression of TERC in prostate cancer. This overexpression occurs at the precursor stage (e.g. high-grade prostatic intraepithelial neoplasia or PIN) and persists throughout all stages of disease progression. Levels of TERC correlate with levels of MYC (a known driver of prostate cancer) in clinical samples and we also show the following: forced reductions of MYC result in decreased TERC levels in eight cancer cell lines (prostate, lung, breast, and colorectal); forced overexpression of MYC in PCa cell lines, and in the mouse prostate, results in increased TERC levels; human TERC promoter activity is decreased after MYC silencing; and MYC occupies the TERC locus as assessed by chromatin immunoprecipitation (ChIP). Finally, we show that knockdown of TERC by siRNA results in reduced proliferation of prostate cancer cell lines. These studies indicate that TERC is consistently overexpressed in all stages of prostatic adenocarcinoma and that its expression is regulated by MYC. These findings nominate TERC as a novel prostate cancer biomarker and therapeutic target. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Rapid Loss of RNA Detection by In Situ Hybridization in Stored Tissue Blocks and Preservation by Cold Storage of Unstained Slides

OBJECTIVES

Recent commercialization of methods for in situ hybridization using Z-pair probe/branched DNA amplification has led to increasing adoption of this technology for interrogating RNA expression in formalin-fixed, paraffin-embedded (FFPE) tissues. Current practice for FFPE block storage is to maintain them at room temperature, often for many years.

METHODS

To examine the effects of block storage time on FFPE tissues using a number of RNA in situ probes with the Advanced Cellular Diagnostic's RNAscope assay.

RESULTS

We report marked reductions in signals after 5 years and significant reductions often after 1 year. Furthermore, storing unstained slides cut from recent cases (<1 year old) at -20°C can preserve hybridization signals significantly better than storing the blocks at room temperature and cutting the slides fresh when needed.

CONCLUSIONS

We submit that the standard practice of storing FFPE tissue blocks at room temperature should be reevaluated to better preserve RNA for in situ hybridization.

Comprehensive Evaluation of TFF3 Promoter Hypomethylation and Molecular Biomarker Potential for Prostate Cancer Diagnosis and Prognosis

Overdiagnosis and overtreatment of clinically insignificant tumors remains a major problem in prostate cancer (PC) due to suboptimal diagnostic and prognostic tools. Thus, novel biomarkers are urgently needed. In this study, we investigated the biomarker potential of Trefoil factor 3 (TFF3) promoter methylation and RNA expression levels for PC. Initially, by quantitative methylation specific PCR (qMSP) analysis of a large radical prostatectomy (RP) cohort (n = 292), we found that the TFF3 promoter was significantly hypomethylated in PC compared to non-malignant (NM) prostate tissue samples (p < 0.001) with an AUC (area under the curve) of 0.908 by receiver operating characteristics (ROC) curve analysis. Moreover, significant TFF3 promoter hypomethylation (p ≤ 0.010) as well as overexpression (p < 0.001) was found in PC samples from another large independent patient sample set (498 PC vs. 67 NM) analyzed by Illumina 450K DNA methylation arrays and/or RNA sequencing. TFF3 promoter methylation and transcriptional expression levels were inversely correlated, suggesting that epigenetic mechanisms contribute to the regulation of gene activity. Furthermore, low TFF3 expression was significantly associated with high ERG, ETS transcription factor (ERG) expression (p < 0.001), as well as with high Gleason score (p < 0.001), advanced pathological T-stage (p < 0.001), and prostate-specific antigen (PSA) recurrence after RP (p = 0.013; univariate Cox regression analysis). There were no significant associations between TFF3 promoter methylation levels, ERG status, or PSA recurrence in these RP cohorts. In conclusion, our results demonstrated diagnostic biomarker potential of TFF3 promoter hypomethylation for PC as well as prognostic biomarker potential of TFF3 RNA expression. To the best of our knowledge, this is the most comprehensive study of TFF3 promoter methylation and transcriptional expression in PC to date.

Hypomethylation associated enhanced transcription of trefoil factor-3 mediates tamoxifen-stimulated oncogenicity of ER+ endometrial carcinoma cells

Tamoxifen (TAM) is widely used as an adjuvant therapy for women with breast cancer (BC). However, TAM possesses partial oestrogenic activity in the uterus and its use has been associated with an increased incidence of endometrial carcinoma (EC). The molecular mechanism for these observations is not well understood. Herein, we demonstrated that forced expression of Trefoil factor 3 (TFF3), in oestrogen receptor-positive (ER+) EC cells significantly increased cell cycle progression, cell survival, anchorage-independent growth, invasiveness and tumour growth in xenograft models. Clinically, elevated TFF3 protein expression was observed in EC compared with normal endometrial tissue, and its increased expression in EC was significantly associated with myometrial invasion. TAM exposure increased expression of TFF3 in ER+ EC cells and its elevated expression resulted in increased oncogenicity and invasiveness. TAM-stimulated expression of TFF3 in EC cells was associated with hypomethylation of the TFF3 promoter sequence and c-JUN/SP1-dependent transcriptional activation. In addition, small interfering (si) RNA-mediated depletion or polyclonal antibody inhibition of TFF3 significantly abrogated oncogenicity and invasiveness in EC cells consequent to TAM induction or forced expression of TFF3. Hence, TAM-stimulated upregulation of TFF3 in EC cells was critical in promoting EC progression associated with TAM treatment. Importantly, inhibition of TFF3 function might be an attractive molecular modality to abrogate the stimulatory effects of TAM on endometrial tissue and to limit the progression of EC.

Novel Assay to Detect RNA Polymerase I Activity In Vivo

This report develops an analytically validated chromogenic in situ hybridization (CISH) assay using branched DNA signal amplification (RNAscope) for detecting the expression of the 5' external transcribed spacer (ETS) of the 45S ribosomal (r) RNA precursor in formalin-fixed and paraffin-embedded (FFPE) human tissues. 5'ETS/45S CISH was performed on standard clinical specimens and tissue microarrays (TMA) from untreated prostate carcinomas, high-grade prostatic intraepithelial neoplasia (PIN), and matched benign prostatic tissues. Signals were quantified using image analysis software. The 5'ETS rRNA signal was restricted to the nucleolus. The signal was markedly attenuated in cell lines and in prostate tissue slices after pharmacologic inhibition of RNA polymerase I (Pol I) using BMH-21 or actinomycin D, and by RNAi depletion of Pol I, demonstrating validity as a measure of Pol I activity. Clinical human prostate FFPE tissue sections and TMAs showed a marked increase in the signal in the presumptive precursor lesion (high-grade PIN) and invasive adenocarcinoma lesions (P = 0.0001 and P = 0.0001, respectively) compared with non-neoplastic luminal epithelium. The increase in 5'ETS rRNA signal was present throughout all Gleason scores and pathologic stages at radical prostatectomy, with no marked difference among these. This precursor rRNA assay has potential utility for detection of increased rRNA production in various tumor types and as a novel companion diagnostic for clinical trials involving Pol I inhibition.Implications: Increased rRNA production, a possible therapeutic target for multiple cancers, can be detected with a new, validated assay that also serves as a pharmacodynamic marker for Pol I inhibitors. Mol Cancer Res; 15(5); 577-84. ©2017 AACR.

Trefoil factor family peptides – friends or foes?

Trefoil factor family (TFF) peptides are a group of molecules bearing a characteristic three-loop trefoil domain. They are mainly secreted in mucous epithelia together with mucins but are also synthesized in the nervous system. For many years, TFF peptides were only known for their wound healing and protective function, e.g. in epithelial protection and restitution. However, experimental evidence has emerged supporting a pivotal role of TFF peptides in oncogenic transformation, tumorigenesis and metastasis. Deregulated expression of TFF peptides at the gene and protein level is obviously implicated in numerous cancers, and opposing functions as oncogenes and tumor suppressors have been described. With regard to the regulation of TFF expression, epigenetic mechanisms as well as the involvement of various miRNAs are new, promising aspects in the field of cancer research. This review will summarize current knowledge about the expression and regulation of TFF peptides and the involvement of TFF peptides in tumor biology and cancerogenesis.

A Novel Immune Marker Model Predicts Oncological Outcomes of Patients with Colorectal Cancer

BACKGROUND

The purpose of this study was to develop an in situ immune marker model to predict postoperative oncological outcomes in patients with colorectal cancer (CRC).

METHODS

Immunohistochemistry for 13 immune cell markers was performed on tumor tissue microarrays from 300 CRC patients who underwent curative resection from January 2000 to January 2006. Genetic algorithm was applied for the construction of an in situ immune marker model.

RESULTS

The infiltration of CD3+ cells, CD45RO+ cells, and FOXP3+ cells, but not the infiltration of Tryptase+ cells, in the tumor was significantly associated with better clinical outcome in overall survival (OS) and disease-free survival (DFS) of CRC patients, as assessed by univariate analysis (P < 0.05). Based on the genetic algorithms, a total of 6 markers, including CD3, CD45RO, IL17, CD15, Tryptase, and FOXP3, were selected to construct an immune marker model. Our model was identified to have an independent predictive capability for both OS and DFS in Cox multivariable model (P < 0.001). This was further confirmed by the ROC analysis (area under curve: OS, 0.669; DFS, 0.684).

CONCLUSIONS

The in situ immune marker model constructed in this study provides a novel approach to identify CRC patients who were at an increased risk for poor oncological outcomes.

HES6 promotes prostate cancer aggressiveness independently of Notch signalling

Notch signalling is implicated in the pathogenesis of a variety of cancers, but its role in prostate cancer is poorly understood. However, selected Notch pathway members are overrepresented in high-grade prostate cancers. We comprehensively profiled Notch pathway components in prostate cells and found prostate cancer-specific up-regulation of NOTCH3 and HES6. Their expression was particularly high in androgen responsive lines. Up- and down-regulating Notch in these cells modulated expression of canonical Notch targets, HES1 and HEY1, which could also be induced by androgen. Surprisingly, androgen treatment also suppressed Notch receptor expression, suggesting that androgens can activate Notch target genes in a receptor-independent manner. Using a Notch-sensitive Recombination signal binding protein for immunoglobulin kappa J region (RBPJ) reporter assay, we found that basal levels of Notch signalling were significantly lower in prostate cancer cells compared to benign cells. Accordingly pharmacological Notch pathway blockade did not inhibit cancer cell growth or viability. In contrast to canonical Notch targets, HES6, a HES family member known to antagonize Notch signalling, was not regulated by Notch signalling, but relied instead on androgen levels, both in cultured cells and in human cancer tissues. When engineered into prostate cancer cells, reduced levels of HES6 resulted in reduced cancer cell invasion and clonogenic growth. By molecular profiling, we identified potential roles for HES6 in regulating hedgehog signalling, apoptosis and cell migration. Our results did not reveal any cell-autonomous roles for canonical Notch signalling in prostate cancer. However, the results do implicate HES6 as a promoter of prostate cancer progression.

Tumor expression of adiponectin receptor 2 and lethal prostate cancer

To investigate the role of adiponectin receptor 2 (AdipoR2) in aggressive prostate cancer we used immunohistochemistry to characterize AdipoR2 protein expression in tumor tissue for 866 men with prostate cancer from the Physicians' Health Study and the Health Professionals Follow-up Study. AdipoR2 tumor expression was not associated with measures of obesity, pathological tumor stage or prostate-specific antigen (PSA) at diagnosis. However, AdipoR2 expression was positively associated with proliferation as measured by Ki-67 expression quartiles (P-trend < 0.0001), with expression of fatty acid synthase (P-trend = 0.001), and with two measures of angiogenesis (P-trend < 0.1). An inverse association was observed with apoptosis as assessed by the TUNEL assay (P-trend = 0.006). Using Cox proportional hazards regression and controlling for age at diagnosis, Gleason score, year of diagnosis category, cohort and baseline BMI, we identified a statistically significant trend for the association between quartile of AdipoR2 expression and lethal prostate cancer (P-trend = 0.02). The hazard ratio for lethal prostate cancer for the two highest quartiles, as compared to the two lowest quartiles, of AdipoR2 expression was 1.9 (95% confidence interval [CI]: 1.2-3.0). Results were similar when additionally controlling for categories of PSA at diagnosis and Ki-67 expression quartiles. These results strengthen the evidence for the role of AdipoR2 in prostate cancer progression.

Trefoil factor 3 (TFF3) enhances the oncogenic characteristics of prostate carcinoma cells and reduces sensitivity to ionising radiation

Trefoil factor 3 (TFF3) is a secreted protein which functions in mucosal repair of the gastrointestinal tract. This is achieved through the combined stimulation of cell migration and prevention of apoptosis and anoikis, thus facilitating repair. Deregulated TFF3 expression at the gene and protein level is implicated in numerous cancers. In prostate cancer TFF3 has previously been reported as a potential biomarker, overexpressed in a subset of primary and metastatic cases. Here we investigated the effect of increased TFF3 expression on prostate cancer cell behaviour. Oncomine analysis demonstrated that TFF3 mRNA expression was upregulated in prostate cancer compared to normal tissue. Forced-expression models were established in the prostate cancer cell lines, DU145 and PC3, by stable transfection of an expression vector containing the TFF3 cDNA. Forced expression of TFF3 significantly increased total cell number and cell viability, cell proliferation and cell survival. In addition, TFF3 enhanced anchorage independent growth, 3-dimensional colony formation, wound healing and cell migration compared to control transfected cell lines. We also observed reduced sensitivity to ionising radiation in stably transfected cell lines. In dose response experiments, forced expression of TFF3 significantly enhanced the regrowth of PC3 cells following ionising radiation compared with control transfected cells. In addition, TFF3 enhanced clonogenic survival of DU145 and PC3 cells. These studies indicate that targeting TFF3 for the treatment of prostate cancer warrants further investigation.

Clinical value of ERG, TFF3, and SPINK1 for molecular subtyping of prostate cancer

BACKGROUND

In view of the marked molecular heterogeneity of prostate cancer (PCa), clinical and pathologic parameters alone may be unreliable for predicting disease outcomes after surgical intervention. The development of biomarkers may be helpful to estimate tumor heterogeneity and stratify patients in terms of their risk of progression. Levels of v-ets avian erythroblastosis virus E26 oncogene homolog (ERG), trefoil factor 3 (TFF3), and serine peptidase inhibitor, Kazal type 1 (SPINK1) are commonly elevated in PCa, but it is unclear whether the evaluation of these 3 markers can help to discriminate patients who will have different clinical outcomes. The authors investigated whether assessment of ERG, TFF3, and SPINK1 expression could help to define clinically relevant, distinct subsets of patients with PCa.

METHODS

The cohort consisted of 279 men with PCa who underwent radical prostatectomy at Henri Mondor Hospital. Expression levels of ERG, TFF3, and SPINK1 were evaluated immunohistochemically in the prostatectomy specimens. Potential associations of ERG, TFF3, and SPINK1 with age, prostate-specific antigen (PSA), tumor stage, Gleason score, and biochemical recurrence, defined by PSA failure, were investigated.

RESULTS

Although prognostic significance was not observed for ERG or TFF3, an exclusive pattern of expression was demonstrated for TFF3 and ERG. SPINK1 expression was observed exclusively in a subgroup of cancers that expressed TFF3 (41 of 175 tumors). Moreover, SPINK1 positivity was identified as predictive of biochemical recurrence in univariate (P = .0009) and multivariate (P = .0003) analyses.

CONCLUSIONS

The current results suggest that ERG and TFF3 characterize 2 distinct subsets of PCa, with a more aggressive subgroup of TFF3-expressing tumors that express SPINK1. Together, these findings support a rationale of screening for these biomarkers for prognostic purposes and molecular subtyping of the disease.

Inhibition of ErbB-2 induces TFF3 downregulation in breast cancer cell lines

ErbB-2 gene plays an important role in carcinoma formation whose overexpression was observed in many types of tumors, including breast cancer. Dysregulation of Trefoil factor 3 (TFF3), which is thought to function in the development and progression of breast cancer, was found to be upregulated in ErbB2-overexpressing breast cancers and cells. However, a putative interaction between ErbB-2 and TFF3 in breast cancer remains unknown. To determine whether TFF3 has an important role in breast tumor, its levels were measured by immunohistochemistry in 130 cases of breast infiltrating duct carcinoma and 30 cases of normal breast tissue with a specific monoclonal antibody raised against human TFF3. Patients who were positive for ErbB-2 also had high expression levels of TFF3 (p < 0.05). Also, after infecting the SK-BR-3 cells with lentivirus-mediated ErbB2-specific shRNA (Lenti-ShERBB2), we detected the expressions of ErbB-2 and TFF3 by real-time polymerase chain reaction and Western blotting, respectively. Compared with the control groups, ErbB-2 mRNA expression was decreased in the Lenti-ShERBB2 infection group, and Western blotting indicated a concordant ErbB-2 protein reduction. On the other hand, TFF3 expression at both mRNA and protein levels was significantly downregulated by ErbB-2 silencing in SK-BR-3. These findings are a proof of the foundation for a certain relationships of ErbB-2 and TFF3, which may serve as novel therapeutic markers of ErbB2-overexpressing breast cancers in the future.

V-ets erythroblastosis virus E26 oncogene homolog (avian)/Trefoil factor 3/high-molecular-weight cytokeratin triple immunostain: a novel tissue-based biomarker in prostate cancer with potential clinical application

Trefoil factor 3 (TFF3) is associated with various cancers and overexpressed in a subset of prostate cancers. Functional studies suggest that v-ets erythroblastosis virus E26 oncogene homolog (avian) (ERG) down-regulates TFF3 expression in hormone-naïve prostate cancer. To characterize this inverse relationship, we developed a triple immunostain encompassing ERG, TFF3, and high-molecular-weight cytokeratin. Triple stain was performed on 96 tumors and 52 benign cases represented in tissue microarrays. Distinct ERG and TFF3 protein was expressed in 45% (43/96) and 36% (35/96) of prostate cancers, respectively. Coexpression was observed in 5% (5/96) of tumor cases, and 24% (23/96) did not express ERG or TFF3. The inverse expression of ERG and TFF3 was significant (P < .0001), with 57% (30/53) of ERG-negative tumors demonstrating TFF3 expression. Sensitivity and specificity of combined ERG and TFF3 expression in detecting prostate cancer were 76% and 96%, respectively. The feasibility of triple immunostain protocol was validated in a set of 76 needle biopsies. The application of this multiplex in situ biomarker for molecular characterization of prostate cancer and as a supplemental diagnostic and prognostic tool in prostate needle biopsies should be further explored.

Trefoil factor 1 suppression of E-CADHERIN enhances prostate carcinoma cell invasiveness and metastasis

Metastasis is the primary mediator of prostate cancer (PCA) lethality and poses a significant clinical obstacle. The identification of factors involved in the metastasis of PCA is imperative. We demonstrate herein that trefoil factor 1 (TFF1) promotes PCA cell migration and invasion in vitro and metastasis in vivo. The capacity of TFF1 to enhance cell migration/invasion is mediated by transcriptional repression of E-CADHERIN. Consideration of targeted inhibition of TFF1 to prevent metastasis of prostate carcinoma is warranted.

Mechanism of growth inhibition of prostate cancer xenografts by valproic acid

Valproic Acid (VPA), a histone deacetylase inhibitor, has been demonstrated to cause a marked decrease in proliferation of prostate cancer (PCa) cells in vitro and a significant reduction in tumor volume in vivo. The goal of this study is to better understand the VPA-induced growth inhibition in vivo, by studying expression of various markers in PCa xenografts. Methods. For in vitro experiments, PCa cells were treated with 0, 0.6, and 1.2 mM VPA for 14 days. For in vivo models, experimental animals received 0.4% VPA in drinking water for 35 days. Tissue microarray was generated using cell pellets and excised xenografts. Results. VPA treatment causes cell cycle arrest in PCa cells in vivo, as determined by increase in p21 and p27 and decrease in cyclin D1 expression. Increased expression of cytokeratin18 was also seen in xenografts. LNCaP xenografts in treated animals had reduced androgen receptor (AR) expression. While decreased proliferation was found in vitro, increase in apoptosis was found to be the reason for decreased tumor growth in vivo. Also, an anti-angiogenic effect was observed after VPA treatment. Conclusion. VPA inhibits tumor growth by multiple mechanisms including cell cycle arrest, induction of differentiation, and inhibition of growth of tumor vasculature.

High trefoil factor 1 (TFF1) expression in human retinoblastoma cells correlates with low growth kinetics, increased cyclin-dependent kinase (CDK) inhibitor levels and a selective down-regulation of CDK6

Trefoil factor family (TFFs) peptides facilitate epithelial restitution, but also effect cell proliferation and apoptosis of normal and various cancer cell lines. In a recent study by our group, TFF2 expression was demonstrated in the murine retina, where it exhibits pro-proliferative and pro-apoptotic effects. In the present study, we investigated the expression and function of TFF peptides in eight human retinoblastoma cell lines. TFF1 was the only TFF peptide expressed at detectable levels in immunoblots of retinoblastoma cells. TFF1 expression levels were highly variable in different retinoblastoma cell lines and negatively correlated with cell growth curves. Recombinant human TFF1 had a negative effect on cell viability and caused a reduction in cell proliferation. Retinoblastoma cell lines with high TFF1 expression levels exhibited a selective down-regulation of cyclin-dependent kinase (CDK) 6, whereas CDK4 and CDK2 seem to be unaffected by TFF1 expression. In immunocytochemical studies, we observed a nuclear co-localization of TFF1 and CDK2 in Cajal bodies (CBs). In high TFF1 expressing human retinoblastoma cell lines CBs were smaller and higher in number compared to retinoblastoma lines with low TFF1 expression, indicating differences in cell cycle status between the different retinoblastoma cell lines. Our data further support the notion for a potential tumor suppressor function of TFF1. The nuclear localization of TFF1 in CBs--considered to play a role in cell cycle progression, potentially acting as a platform for CDK-cyclin function-offers a new impetus in the ongoing search for potential TFF1 interacting proteins.

Poly[3-(3, 4-dihydroxyphenyl) glyceric acid] from Comfrey exerts anti-cancer efficacy against human prostate cancer via targeting androgen receptor, cell cycle arrest and apoptosis

The major obstacles in human prostate cancer (PCA) treatment are the development of resistance to androgen ablation therapy leading to hormone-refractory state and the toxicity associated with chemotherapeutic drugs. Thus, the identification of additional non-toxic agents that are effective against both androgen-dependent and androgen-independent PCA is needed. In the present study, we investigated the efficacy of a novel phytochemical poly[3-(3, 4-dihydroxyphenyl)glyceric acid] (p-DGA) from Caucasian species of comfrey (Symphytum caucasicum) and its synthetic derivative syn-2, 3-dihydroxy-3-(3, 4-dihydroxyphenyl) propionic acid (m-DGA) against PCA LNCaP and 22Rv1 cells. We found that both p-DGA and m-DGA suppressed the growth and induced death in PCA cells, with comparatively lesser cytotoxicity towards non-neoplastic human prostate epithelial cells. Furthermore, we also found that both p-DGA and m-DGA caused G(1) arrest in PCA cells through modulating the expression of cell cycle regulators, especially an increase in CDKIs (p21 and p27). In addition, p-DGA and m-DGA induced apoptotic death by activating caspases, and also strongly decreased AR and PSA expression. Consistent with in vitro results, our in vivo study showed that p-DGA feeding strongly inhibited 22Rv1 tumors growth by 76% and 88% at 2.5 and 5mg/kg body weight doses, respectively, without any toxicity, together with a strong decrease in PSA level in plasma; and a decrease in PCNA, AR and PSA expression but increase in p21/p27 expression and apoptosis in tumor tissues from p-DGA-fed mice. Overall, present study identifies p-DGA as a potent agent against PCA without any toxicity, and supports its clinical application.

Neuropilin-2: a novel biomarker for malignant melanoma?

Neuropilin-2, a cell surface receptor involved in angiogenesis and axonal guidance, has recently been shown to be a critical mediator of tumor-associated lymphangiogenesis. Given that lymphangiogenesis is a major conduit of metastasis in melanomas and that blocking neuropilin-2 function in vivo is effective in inhibiting tumor cell metastasis, we sought to determine the clinical relevance of neuropilin-2 expression in cutaneous melanoma. Immunohistochemical analysis of neuropilin-2 expression was evaluated in nevomelanocytic proliferations that included a tissue microarray and histologic sections from samples of primary melanomas (n = 42; 40 for tissue microarray, 2 for histologic sections), metastatic melanomas (n = 30; 22 for tissue microarray, 8 for histologic sections), and nevi (n = 30; 5 for tissue microarray, 25 for histologic sections), as well as a panel of normal human tissues and select nonmelanocytic tumors. Staining for grading and intensity of neuropilin-2 expression was estimated semiquantitatively as follows for the former: less than 20%, 20% to 60%, and more than 60% of tissue present, and for the latter from 0 to 3, with 3 being the highest and 0 the lowest intensity. In nevomelanocytic proliferations, more than 20% staining for neuropilin-2 was noted in 36 (86%) of 42 cases of primary melanoma, in 27 (90%) of 30 cases of metastatic melanoma, and in 9 (30%) of 30 cases of nevi with differences achieving statistical significance between melanoma (primary and metastatic) and nevi (P < .0001). For staining intensity, an intensity of 2 or more was noted in 36 (86%) of 42 cases of primary melanoma, in 17 (57%) of 30 cases of metastatic melanoma and in 7 (30%) of 23 cases of nevi, with differences achieving statistical significance between melanoma (primary and metastatic) and nevi (P < .0001). In normal human tissue, consistently strong neuropilin-2 staining was noted in kidney (glomerular endothelial cells, collecting tubules, and collecting ducts), skin (epidermal keratinocytes), and testes (epithelium of the seminiferous tubules), whereas in tumoral tissue, consistently strong staining was noted only in renal cell carcinoma but not in any of the other tumors studied. More recently, using a heterotypic coculture methodology with melanoma and endothelial cells, we have demonstrated successful up-regulation of neuropilin-2 and confirmed the critical role of neuropilin-2 in melanoma-endothelial interactions. Because these coculture methods were developed to model melanoma metastasis, the significantly increased and enhanced expression of neuropilin-2 staining in primary and metastatic melanoma versus nevi in the current study suggests that it is also relevant in vivo.

Trefoil factor 3 is oncogenic and mediates anti-estrogen resistance in human mammary carcinoma

We report herein that trefoil factor 3 (TFF3) is oncogenic and mediates anti-estrogen resistance in human mammary carcinoma. Forced expression of TFF3 in mammary carcinoma cells increased cell proliferation and survival, enhanced anchorage-independent growth, and promoted migration and invasion. Moreover, forced expression of TFF3 increased tumor size in xenograft models. Conversely, depletion of endogenous TFF3 with small interfering RNA (siRNA) decreased the oncogenicity and invasiveness of mammary carcinoma cells. Neutralization of secreted TFF3 by antibody promoted apoptosis, decreased cell growth in vitro, and arrested mammary carcinoma xenograft growth. TFF3 expression was significantly correlated to decreased survival of estrogen receptor (ER)-positive breast cancer patients treated with tamoxifen. Forced expression of TFF3 in mammary carcinoma cells increased ER transcriptional activity, promoted estrogen-independent growth, and produced resistance to tamoxifen and fulvestrant in vitro and to tamoxifen in xenograft models. siRNA-mediated depletion or antibody inhibition of TFF3 significantly enhanced the efficacy of antiestrogens. Increased TFF3 expression was observed in tamoxifen-resistant (TAMR) cells and antibody inhibition of TFF3 in TAMR cells improved tamoxifen sensitivity. Functional antagonism of TFF3 therefore warrants consideration as a novel therapeutic strategy for mammary carcinoma.

ERG cooperates with androgen receptor in regulating trefoil factor 3 in prostate cancer disease progression

To elucidate the role of ETS gene fusions in castration-resistant prostate cancer (CRPC), we characterized the transcriptome of 54 CRPC tumor samples from men with locally advanced or metastatic disease. Trefoil factor 3 (TFF3) emerged as the most highly differentially regulated gene with respect to ERG rearrangement status and resistance to hormone ablation therapy. Conventional chromatin immunoprecipitation (ChIP)-polymerase chain reaction and ChIP followed by DNA sequencing (ChIP-seq) revealed direct binding of ERG to ETS binding sites in the TFF3 promoter in ERG-rearranged prostate cancer cell lines. These results were confirmed in ERG-rearranged hormone-naive prostate cancer (HNPC) and CRPC tissue samples. Functional studies demonstrated that ERG has an inhibitory effect on TFF3 expression in hormone-naive cancer but not in the castration-resistant state. In addition, we provide evidence suggesting an effect of androgen receptor signaling on ERG-regulated TFF3 expression. Furthermore, TFF3 overexpression enhances ERG-mediated cell invasion in CRPC prostate cancer cells. Taken together, our findings reveal a novel mechanism for enhanced tumor cell aggressiveness resulting from ERG rearrangement in the castration-resistant setting through TFF3 gene expression.

Does valproic acid induce neuroendocrine differentiation in prostate cancer?

Valproic Acid (VPA) is a histone deacetylase inhibitor that holds promise for cancer therapy. Here, we investigate whether VPA treatment induces neuroendocrine differentiation of Prostate Cancer (PCa). A tissue microarray of VPA-treated and untreated tumor xenografts and cell lines of human PCa (LNCaP, C4-2, DU145, and PC-3) were generated and were analyzed by immunohistochemical analysis (IHC) for NE markers chromogranin A (CgA), synaptophysin, and NCAM (neural cell adhesion molecule). Western blot analysis for CgA was performed to confirm the results of the TMA. IHC analysis did not reveal any induction of CgA, synaptophysin, or NCAM in any xenograft after VPA treatment in vivo. In vitro, VPA treatment induced little synaptophysin expression in C4-2 and PC-3 cells and NCAM expression in LNCaP and PC-3 cells. In the case of CgA, VPA treatment decreased its expression in vitro in a dose-dependent manner, as determined by western blot analysis. Thus our data demonstrates that VPA does not induce NE differentiation of PCa cells in the physiologically relevant in vivo setting.

Promoter hypomethylation and upregulation of trefoil factors in prostate cancer

Trefoil factors, mucin-associated peptides, are overexpressed in prostate cancer (PC). We hypothesized that promoter methylation contributes to the regulation of trefoil factors (TFF1, TFF2 and TFF3) in human prostate cells. Here we show hypomethylation of promoter regions of TFF1 and TFF3 in PC cell lines with significant TFF expression as compared to benign immortalized prostate cell lines and PC cell lines not expressing trefoil factor. The most striking difference was observed for CpG sites located close to the AUG start codon overlapping several putative binding sites for cellular transcription factors. TFF2 was hypermethylated and had no or very low expression in all prostate cell lines investigated. Treatment of methylated cell lines with 5-aza-2'-deoxycytidine restored TFF expression in cell lines not expressing TFF and increased expression significantly in low-expressing cell lines. In clinical samples, methylation of the promoter/enhancer regions of TFF1 and TFF3 was significantly lower in PC compared to benign prostatic hyperplasia. The present study shows an inverse relation between promoter methylation and expression of trefoil factors. Preliminary analysis on clinical samples suggests that this regulatory mechanism is responsible for the increased levels of TFF1 and TFF3 observed in PC. The overexpression and promoter hypomethylation of trefoil factors may serve as biomarkers in PC.

A transcriptional signature associated with the onset of benign prostate hyperplasia in a canine model

BACKGROUND

Benign prostatic hyperplasia (BPH) represents the most frequent proliferative abnormality of the human prostate. In spite of the well-characterized architectural development of BPH, little is known about the cellular and molecular events that contribute to it.

METHODS

We have developed an animal model to evaluate the follow-up of hormone-induced BPH and the analysis of the gene expression associated with BPH. Immunohistochemistry on human patient samples validated the BPH-related molecular alterations.

RESULTS

Canine specific Affymetrix microarray analysis performed on sequential biopsies obtained from a beagle dog dynamic model characterized a number of genes altered during the onset of BPH. In addition to the genes involved in calcification, matrix remodeling, detoxification, cell movement, and mucosa protection (MGP, MMP2, TIMP2, ITIH3, GST, MT2A, SULT1A1, FKBP1B, MUC1, STRBP, TFF3), the up-regulation of TGFB3 and CLU indicated a complete adjustment of the transdifferentiation, senescence and apoptosis programs. The up-regulation of Clusterin was validated by RT-qPCR and immunohistochemistry, both in the dog dynamic model and in human samples, further confirming the suitability of the animal model for the study of the molecular alterations associated with BPH.

CONCLUSIONS

Transcriptome analysis performed on a dynamic animal model that accurately mimicked the human clinic, allowed us to characterize a gene expression pattern associated with the onset of BPH.

NKX3.1 as a marker of prostatic origin in metastatic tumors

NKX3.1 is a prostatic tumor suppressor gene located on chromosome 8p. Although most studies have shown that staining for NKX3.1 protein is positive in the majority of primary prostatic adenocarcinomas, it has been shown to be downregulated in many high-grade prostate cancers, and completely lost in the majority of metastatic prostate cancers (eg, in 65% to 78% of lesions). A recent study showed that NKX3.1 staining with a novel antibody was highly sensitive and specific for high-grade prostatic adenocarcinoma when compared with high-grade urothelial carcinoma. This raised the question that this antibody may perform better than earlier used antibodies in metastatic prostate tumors. However, the sensitivity and specificity for prostate carcinomas for this antibody in metastatic lesions was not determined. Although prostate-specific antigen (PSA) and prostatic-specific acid phosphatase (PSAP) are excellent tissue markers of prostate cancer, at times they may be expressed at low levels, focally, or not at all in poorly differentiated primary and metastatic prostatic adenocarcinomas. The purpose of this study was to determine the performance of NKX3.1 as a marker of metastatic adenocarcinoma of prostatic origin. Immunohistochemical staining against NKX3.1, PSA, and PSAP was carried out on a tissue microarray (TMA) (0.6-mm tissue cores) of hormone naïve metastatic prostate adenocarcinoma specimens from lymph nodes, bone, and soft tissue. To determine the specificity of NKX3.1 for prostatic adenocarcinoma, we used TMAs that contained cancers from various sites including the urinary bladder, breast, colon, salivary gland, stomach, pancreas, thyroid, and central nervous system, and standard paraffin sections of cancers from other sites including the adrenal cortex, kidney, liver, lung, and testis. Overall 349 nonprostatic tumors were evaluated. Any nuclear staining for NKX3.1 was considered positive and the percentage of cells with nuclear staining and their mean intensity level were assessed visually. Sensitivity was calculated by considering a case positive if any TMA core was positive. The sensitivity for identifying metastatic prostatic adenocarcinomas overall was 98.6% (68/69 cases positive) for NKX3.1, 94.2% (65/69 cores positive) for PSA, and 98.6% (68/69 cores positive) for PSAP. The specificity of NKX3.1 was 99.7% (1/349 nonprostatic tumors positive). The sole positive nonprostatic cancer case was an invasive lobular carcinoma of the breast. NKX3.1 seems to be a highly sensitive and specific tissue marker of metastatic prostatic adenocarcinoma. In the appropriate clinical setting, the addition of IHC staining for NKX3.1, along with other prostate-restricted markers, may prove to be a valuable adjunct to definitively determine prostatic origin in poorly differentiated metastatic carcinomas.

Variability in the androgen response of prostate epithelium to 5alpha-reductase inhibition: implications for prostate cancer chemoprevention

Inhibitors of 5alpha-reductase (SRD5A) that lower intraprostatic levels of dihydrotestosterone (DHT) reduce the overall incidence of prostate cancer (PCa), but there is significant variation in chemopreventive activity between individual men. In seeking molecular alterations that might underlie this variation, we compared gene expression patterns in patients with localized PCa who were randomized to prostatectomy alone versus treatment with two different doses of the SRD5A inhibitor dutasteride. Prostatic levels of DHT were decreased by >90% in both dutasteride-treated patient groups versus the untreated patient group. Despite significant and uniform suppression of tissue DHT, unsupervised clustering based on prostatic gene expression did not discriminate these groups. However, subjects could be resolved into distinct cohorts characterized by high or low expression of genes regulated by the androgen receptor (AR), based solely on AR transcript expression. The higher-dose dutasteride treatment group was found to include significantly fewer cancers with TMPRSS2-ERG genetic fusions. Dutasteride treatment was associated with highly variable alterations in benign epithelial gene expression. Segregating subjects based on expression of AR and androgen-regulated genes revealed that patients are differentially sensitive to SRD5A inhibition. Our findings suggest that AR levels may predict the chemopreventive efficacy of SRD5A inhibitors.

Digital microscopy for boosting database integration and analysis in TMA studies

The enormous amount of clinical, pathological, and staining data to be linked, analyzed, and correlated in a tissue microarray (TMA) project makes digital slides ideal to be integrated into TMA database systems. With the help of a computer and dedicated software tools, digital slides offer dynamic access to microscopic information at any magnification with easy navigation, annotation, measurement, and archiving features. Advanced slide scanners work both in transmitted light and fluorescent modes to support biomarker testing with immunohistochemistry, immunofluorescence or fluorescence in situ hybridization (FISH). Currently, computer-driven integrated systems are available for creating TMAs, digitalizing TMA slides, linking sample and staining data, and analyzing their results. Digital signals permit image segmentation along color, intensity, and size for automated object quantification where digital slides offer superior imaging features and batch processing. In this chapter, the workflow and the advantages of digital TMA projects are demonstrated through the project-based MIRAX system developed by 3DHISTECH and supported by Zeiss.The enhanced features of digital slides compared with those of still images can boost integration and intelligence in TMA database management systems, offering essential support for high-throughput biomarker testing, for example, in tumor progression/prognosis, drug discovery, and target therapy research.

Cell-autonomous intracellular androgen receptor signaling drives the growth of human prostate cancer initiating cells

BACKGROUND

The lethality of prostate cancer is due to the continuous growth of cancer initiating cells (CICs) which are often stimulated by androgen receptor (AR) signaling. However, the underlying molecular mechanism(s) for such AR-mediated growth stimulation are not fully understood. Such mechanisms may involve cancer cell-dependent induction of tumor stromal cells to produce paracrine growth factors or could involve cancer cell autonomous autocrine and/or intracellular AR signaling pathways.

METHODS

We utilized clinical samples, animal models and a series of AR-positive human prostate cancer cell lines to evaluate AR-mediated growth stimulation of prostate CICs.

RESULTS

The present studies document that stromal AR expression is not required for prostate cancer growth, since tumor stroma surrounding AR-positive human prostate cancer metastases (N = 127) are characteristically AR-negative. This lack of a requirement for AR expression in tumor stromal cells is also documented by the fact that human AR-positive prostate cancer cells grow equally well when xenografted in wild-type versus AR-null nude mice. AR-dependent growth stimulation was documented to involve secretion, extracellular binding, and signaling by autocrine growth factors. Orthotopic xenograft animal studies documented that the cellautonomous autocrine growth factors which stimulate prostate CIC growth are not the andromedins secreted by normal prostate stromal cells. Such cell autonomous and extracellular autocrine signaling is necessary but not sufficient for the optimal growth of prostate CICs based upon the response to anti-androgen plus/or minus preconditioned media.

CONCLUSIONS

AR-induced growth stimulation of human prostate CICs requires AR-dependent intracellular pathways. The identification of such AR-dependent intracellular pathways offers new leads for the development of effective therapies for prostate cancer.

Bladder cancer-associated protein, a potential prognostic biomarker in human bladder cancer

It is becoming increasingly clear that no single marker will have the sensitivity and specificity necessary to be used on its own for diagnosis/prognosis of tumors. Interpatient and intratumor heterogeneity provides overwhelming odds against the existence of such an ideal marker. With this in mind, our laboratory has been applying a long term systematic approach to identify multiple biomarkers that can be used for clinical purposes. As a result of these studies, we have identified and reported several candidate biomarker proteins that are deregulated in bladder cancer. Following the conceptual biomarker development phases proposed by the Early Detection Research Network, we have taken some of the most promising candidate proteins into postdiscovery validation studies, and here we report on the characterization of one such biomarker, the bladder cancer-associated protein (BLCAP), formerly termed Bc10. To characterize BLCAP protein expression and cellular localization patterns in benign bladder urothelium and urothelial carcinomas (UCs), we used two independent sets of samples from different patient cohorts: a reference set consisting of 120 bladder specimens (formalin-fixed as well as frozen biopsies) and a validation set consisting of 2,108 retrospectively collected UCs with long term clinical follow-up. We could categorize the UCs examined into four groups based on levels of expression and subcellular localization of BLCAP protein and showed that loss of BLCAP expression is associated with tumor progression. The results indicated that increased expression of this protein confers an adverse patient outcome, suggesting that categorization of staining patterns for this protein may have prognostic value. Finally, we applied a combinatorial two-marker discriminator using BLCAP and adipocyte-type fatty acid-binding protein, another UC biomarker previously reported by us, and found that the combination of the two markers correlated more closely with grade and/or stage of disease than the individual markers. The implications of these results in biomarker discovery are discussed.

Phase II, randomized, placebo-controlled trial of neoadjuvant celecoxib in men with clinically localized prostate cancer: evaluation of drug-specific biomarkers

PURPOSE

Cyclooxygenase-2 (COX-2) is a potential pharmacologic target for the prevention of various malignancies, including prostate cancer. We conducted a randomized, double-blind trial to examine the effect of celecoxib on drug-specific biomarkers from prostate tissue obtained at prostatectomy.

PATIENTS AND METHODS

Patients with localized prostate cancer and Gleason sum > or = 7, prostate-specific antigen (PSA) > or = 15 ng/mL, clinical stage T2b or greater, or any combination with greater than 45% risk of capsular penetration were randomly assigned to celecoxib 400 mg by mouth twice daily or placebo for 4 to 6 weeks before prostatectomy. The primary end point was the difference in prostatic prostaglandin levels between the two groups. Secondary end points were differences in COX-1 and -2 expressions; oxidized DNA bases; and markers of proliferation, apoptosis and angiogenesis. Tissue celecoxib concentrations also were measured. Tertiary end points were drug safety and compliance.

RESULTS

Seventy-three patients consented, and 64 were randomly assigned and included in the intention-to-treat analysis. There were no treatment differences in any of the primary or secondary outcomes. Multivariable regression revealed that tumor tissue had significantly lower COX-2 expression than benign prostatic tissue (P = .01) and significantly higher levels of the proliferation marker Ki-67 (P < .0001). Celecoxib was measurable in prostate tissue of patients on treatment, demonstrating that celecoxib reached its target. Celecoxib was safe and resulted in only grade 1 toxicities.

CONCLUSION

Treatment with 4 to 6 weeks of celecoxib had no effect on intermediate biomarkers of prostate carcinogenesis, despite the achievement of measurable tissue levels. We caution against using celecoxib 400 mg twice daily as a preventive agent for prostate cancer in additional studies.

pS2 (TFF1) expression in prostate carcinoma: correlation with steroid receptor status

pS2 or TFF1 is a member of the trefoil factor family, which is distributed throughout the gastrointestinal tract in both normal and diseased tissues. It is also considered to be one of the major estrogen-regulated proteins and an indicator of estrogen receptor (ER) functionality. pS2 has previously been investigated in benign and malignant prostate lesions with little information about its relationship to steroid receptor status. Our purpose was to correlate pS2 expression with steroid receptor status (ER alpha and progesterone receptor (PR)) and other pathologic variables in prostate carcinoma. 15 benign prostate hyperplasia (BPH) and 47 prostate carcinoma cases were investigated by means of immunohistochemistry for pS2, ER and PR expression. 80% of BPH showed pS2 cytoplasmic immunoreactivity in hyperplastic acini and about half of these cases also exhibited nuclear staining decorating basal or both basal and luminal nuclei. pS2 was highly expressed in prostate carcinoma (91.4%) with both cytoplasmic and nuclear patterns of staining. The latter pattern was significantly associated with carcinoma having a low Gleason score (p=0.02). pS2 lacked any significant correlation with steroid receptor status, stage or grade. Univariate survival analysis revealed a significant impact of stage (p=0.03) and nodal status (p<0.0001) on patient outcome. The diagnostic value of pS2 expression in prostate carcinoma validated 74.19% accuracy, 91.48% sensitivity and 78.18% positive predictive value. The high sensitivity of pS2 expression in prostate carcinoma could make it a suitable marker for diagnosis of prostate carcinoma, especially in metastatic cases of unknown origin. The absence of correlation and dissimilarity in immunolocalization between pS2 and ER alpha leads to the assumption that ER alpha could not be the regulatory protein for pS2 and may raise questions about the functionality of ER alpha in prostate. The nuclear pattern of pS2 immunoreactivity either in benign or malignant prostatic lesions is similar to the published data on ER beta distribution and could also identify a subset of carcinoma patients with a favorable prognosis.

Creation, validation, and quantitative analysis of protein expression in vascular tissue microarrays

BACKGROUND

Tissue microarrays (TMAs) are collections of multiple tissue cores placed in parallel in a single acceptor block and traditionally used to investigate protein expression in neoplastic tissues. We validated the use of TMAs to investigate protein expression in vascular segments.

METHODS

Vascular tissues were collected from 100 adult subjects undergoing autopsy. A diverse set of vessels were harvested and arrayed over 17 TMAs. A total of 1377 unique tissues, each with a 1.5-mm feature size, were analyzed using histochemical and immunohistochemical (IHC) diaminobenzidine (DAB) methods.

RESULTS

Histomorphometric analysis of vascular disease demonstrated the TMA features captured the majority of the vascular alterations (intimal hyperplasia and atherosclerosis) seen in the original blood vessel section. Measurements of IHC staining intensity based on color deconvolution were used to quantify antigen abundance in defined regions of interest (ROI). Validation was performed using antibodies to connective tissue growth factor (CTGF), receptor for advanced glycation end products (AGER/RAGE), and matrix metalloproteinase 3 (MMP-3). IHC staining was highly correlated between duplicate features from the same vascular site over these three proteins.

CONCLUSION

This study validates the use of TMA technology to investigate the vascular wall utilizing staining intensity data.

Tissue microarray analysis of eIF4E and its downstream effector proteins in human breast cancer

Background

Eukaryotic initiation factor 4E (eIF4E) is elevated in many cancers and is a prognostic indicator in breast cancer. Many pro-tumorigenic proteins are selectively translated via eIF4E, including c-Myc, cyclin D1, ornithine decarboxylase (ODC), vascular endothelial growth factor (VEGF) and Tousled-like kinase 1B (TLK1B). However, western blot analysis of these factors in human breast cancer has been limited by the availability of fresh frozen tissue and the labor-intensive nature of the multiple assays required. Our goal was to validate whether formalin-fixed, paraffin-embedded tissues arranged in a tissue microarray (TMA) format would be more efficient than the use of fresh-frozen tissue and western blot to test multiple downstream gene products.

Results

Breast tumor TMAs were stained immunohistochemically and quantitated using the ARIOL imaging system. In the TMAs, eIF4E levels correlated strongly with c-Myc, cyclin D1, TLK1B, VEGF, and ODC. Western blot comparisons of eIF4E vs. TLK1B were consistent with the immunohistochemical results. Consistent with our previous western blot results, eIF4E did not correlate with node status, ER, PR, or HER-2/neu.

Conclusion

We conclude that the TMA technique yields similar results as the western blot technique and can be more efficient and thorough in the evaluation of several products downstream of eIF4E.

Trefoil factor 3 (TFF3): a promising indicator for diagnosing thyroid follicular carcinoma

Since the introduction of fine needle aspiration biopsy (FNAB) in the 1970's, a preoperative diagnostic technique for thyroid follicular carcinoma has long been awaited. Many markers that distinguish follicular carcinomas from adenomas have been reported; however, most of them have not been confirmed to be beneficial for clinical use. Trefoil factor 3 (TFF3) is a relatively new family of peptides that bears the three-loop trefoil domain. Several groups have reported that the suppression of TFF3 mRNA expression is related to malignant characteristics of thyroid follicular cell-derived tumors and the expression level of TFF3 mRNA is the most promising indicator for diagnosing follicular carcinoma. Development of TFF3-based diagnostic methods is now ongoing and it may not be long before thyroid follicular carcinoma can be diagnosed preoperatively using an aspirated sample from the tumor.

DNA hypomethylation arises later in prostate cancer progression than CpG island hypermethylation and contributes to metastatic tumor heterogeneity

Hypomethylation of CpG dinucleotides in genomic DNA was one of the first somatic epigenetic alterations discovered in human cancers. DNA hypomethylation is postulated to occur very early in almost all human cancers, perhaps facilitating genetic instability and cancer initiation and progression. We therefore examined the nature, extent, and timing of DNA hypomethylation changes in human prostate cancer. Contrary to the prevailing view that global DNA hypomethylation changes occur extremely early in all human cancers, we show that reductions in (5me)C content in the genome occur very late in prostate cancer progression, appearing at a significant extent only at the stage of metastatic disease. Furthermore, we found that, whereas some LINE1 promoter hypomethylation does occur in primary prostate cancers compared with normal tissues, this LINE1 hypomethylation is significantly more pronounced in metastatic prostate cancer. Next, we carried out a tiered gene expression microarray and bisulfite genomic sequencing-based approach to identify genes that are silenced by CpG island methylation in normal prostate cells but become overexpressed in prostate cancer cells as a result of CpG island hypomethylation. Through this analysis, we show that a class of cancer testis antigen genes undergoes CpG island hypomethylation and overexpression in primary prostate cancers, but more so in metastatic prostate cancers. Finally, we show that DNA hypomethylation patterns are quite heterogeneous across different metastatic sites within the same patients. These findings provide evidence that DNA hypomethylation changes occur later in prostate carcinogenesis than the CpG island hypermethylation changes and occur heterogeneously during prostate cancer progression and metastatic dissemination.