L1 cell adhesion molecule overexpression in hepatocellular carcinoma associates with advanced tumor progression and poor patient survival

Background

To investigate the expression of Golgi phosphoprotein-3 (GOLPH3) in prostate cancer and determine its prognostic value.

Methods

Immunohistochemical staining for GOLPH3 was performed on tissue microarrays of 342 prostate patients. The correlation between GOLPH3 expression with its clinicopathologic factors was also analyzed in order to determine its prognostic significance.

Results

GOLPH3 expression of normal prostate tissues, benign prostate hyperplasia, high-grade prostatic intraepithelial neoplasia, and hormone-dependent prostate cancer (HDPC) did not show any statistically significant difference. In contrast, statistically significant difference was reported in moderate/intense GOLPH3 expression in cases diagnosed with HDPC and castration resistant prostate cancer (CRPC) (P < 0.0005). Moderate /intense expression of GOLPH3 was associated with androgen independence (P?=?0.012), higher Gleason score (P?=?0.017), bone metastasis (P?=?0.024), higher baseline prostate-specific antigen (PSA) (P?=?0.038), and higher PSA nadir (P?=?0.032). A significantly negative correlation was found between moderate/intense GOLPH3 expression and disease-free survival (DFS) (HR?=?0.28, P?=?0.012) and overall survival (OS) (HR?=?0.42, P?=?0.027). Univariated analysis indicated that moderate/intense GOLPH3 expression created a significantly prognostic impact in patients with CRPC. On the other hand, multivariate analysis indicated that GOLPH3 was a significantly independent prognostic factor of DFS (P?=?0.027) in all prostate cancer patients.

Conclusions

In this study, it was discovered that the overexpression of GOLPH3 is associated with the transition of prostate cancer from hormone sensitive phase to hormone refractory phase. GOLPH3 might be an important prognostic factor of DFS and OS in patients with prostate cancer. In totality, GOLPH3 could be used as a novel candidate in devising a more effective therapeutic strategy to tackle CRPC.

Virtual slides

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1452541171722856.     

Intratumor heterogeneity and clonal evolution revealed in castration-resistant prostate cancer by longitudinal genomic analysis

Intratumor heterogeneity is a key driver for local relapse and treatment failure. Thus, using multifocal prostate cancer as a model to investigate tumor inter-clonal relationships and tumor evolution could aid in our understanding of drug resistance. Previous studies discovered genomic alterations by comparing hormone-sensitive prostate cancer (HSPC) with castration-resistant prostate cancer (CRPC) in large cohorts. However, most studies did not sequentially sample tumors from the same patient. In our study, we performed whole-exome sequencing (WES) on 14 specimens from five locally relapsed patients before and after androgen-deprivation therapy. We described the landscape of genomic alterations before and after treatment and identified critical driver events that could have contributed to the evolution of CRPC. In addition to confirming known cancer genes such as TP53 and CDK12, we also identified new candidate genes that may play a role in the progression of prostate cancer, including MYO15A, CHD6 and LZTR1. At copy number alteration (CNA) level, gain of 8q24.13-8q24.3 was observed in 60% of patients and was the most commonly altered locus in both HSPC and CRPC tumors. Finally, utilizing phylogenetic reconstruction, we explored the clonal progression pattern from HSPC to CRPC in each patient. Our findings highlight the complex and heterogeneous mechanisms underlying the development of drug resistance, and underscore the potential value of monitoring tumor clonal architectures during disease progression in a clinical setting.     

Clinicopathological characteristics of androgen receptor splicing variant 7 (AR-V7) expression in patients with castration resistant prostate cancer: A systematic review and meta‐analysis

Background Studies have shown that AR-V7 may be correlated with the poor prognosis of castration resistant prostate cancer (CRPC), however, clinicopathological characteristics of AR-V7 have not been fully elucidated.ObjectiveThis study aimed at evaluating the clinicopathological features of AR-V7 in CRPC patients.Materials and methodsTo evaluate the clinicopathological features of AR-V7 in CRPC patients. A search of PubMed, Embase, and Web of Science was performed using the keywords prostate cancer, prostate tumor, prostate neoplasm, prostate carcinoma, AR-V7, AR3, androgen receptor splicing variant-7, or androgen receptor-3. Twenty-four trials published by February 2020 were included in this study.ResultsThe proportion of Gleason score ≥ 8 was found to be significantly higher in AR-V7-positive CRPC (69.5%) than negative (54.9%) (OR 1.68, 95% CI 1.25–2.25, p < 0.001), while the rates of T3/T4 stage (OR 1.16, 95% CI 0.60–2.24, p = 0.65) and N1 stage (OR 0.99, 95% CI 0.65–1.51, p = 0.96) were not statistically correlated with AR-V7 status. The AR-V7-positive patients exhibited a significantly higher proportion of any site metastasis (61.3% versus 35.0%; OR 2.19, 95% CI 1.57–3.05, p < 0.001) and bone metastasis (81.7% versus 69.0%; OR 1.97, 95% CI 1.44–2.69, p < 0.001), and a trend close to significance was expected in visceral metastasis (28.8% versus 22.1%; OR 1.29, 95% CI 0.96–1.74, p = 0.09). Incidences of pain in AR-V7-positive CRPC (54.6%) were significantly higher than in negative CRPC (28.1%; OR 4.23, 95% CI 2.52–7.10, p < 0.001), line with worse ECOG performance status (56.7% versus 35.0%, OR 2.18, 95% CI 1.51–3.16, P < 0.001). Limitations of the study include differences in sample sizes and designs, AR-V7 detection assays, as well as disease characteristics of the included studies.ConclusionsAR-V7 positivity is associated with a higher Gleason score, bone or any site metastasis, pain and worse ECOG performance scores in CRPC. However, it is not correlated with tumor stage or lymph node metastasis. More studies are needed to confirm these findings.     

Comparable amounts of sex steroids are made outside the gonads in men and women: Strong lesson for hormone therapy of prostate and breast cancer

The objective of this study was comparison of circulating androgens and their metabolites as well as estrogens measured for the first time by a validated mass spectrometry technology in 60–80-year-old men and women of comparable age.Castration in men (n = 34) reduces the total androgen pool by only about 60% as indicated by the decrease in the serum levels of the glucuronide metabolites of androgens compared to intact men (n = 1302). Such data are in agreement with the 50 to 75% decrease in intraprostatic dihydrotestosterone (DHT) concentration after castration. Most interestingly, the same amounts of androgens and estrogens are found in postmenopausal women (n = 369) and castrated men of comparable age.The most significant therapeutic implication of these findings is the absolute need to add a pure (nonsteroidal) antiandrogen to castration in men with prostate cancer in order to block the action of the 25 to 50% DHT left in the prostate after castration. Not adding an antiandrogen to castration in men treated for prostate cancer is equivalent to not prescribing a blocker of estrogens in women suffering from breast cancer because they are postmenopausal and have low circulating estradiol.     

MK591, a Second Generation Leukotriene Biosynthesis Inhibitor,Prevents Invasion and Induces Apoptosis in the Bone-Invading C4-2B Human Prostate Cancer Cells: Implications for the Treatment of Castration-Resistant,Bone-Metastatic Prostate Cancer

Castration-resistant prostate cancer (CRPC) is a major clinical challenge for which no cure is currently available primarily because of the lack of proper understanding about appropriate molecular target(s). Previously we observed that inhibition of 5-lipoxygenase (5-Lox) activity induces apoptosis in some types of prostate cancer cells, suggesting an important role of 5-Lox in the viability of prostate cancer cells. However, nothing is known about the role of 5-Lox in the survival of castration-resistant, metastatic prostate cancer cells. Thus, we tested the effects of MK591, a second-generation, specific inhibitor of 5-Lox activity, on the viability and metastatic characteristics of CRPC cells. We observed that MK591 effectively kills the bone-invading C4-2B human prostate cancer cells (which bear characteristics of CRPC), but does not affect normal, non-cancer fibroblasts (which do not express 5-Lox) in the same experimental conditions. We also observed that MK591 dramatically inhibits the in vitro invasion and soft-agar colony formation of C4-2B cells. Interestingly, we found that treatment with MK591 dramatically down-regulates the expression of c-Myc and its targets at sub-lethal doses. In light of frequent over-activation of c-Myc in a spectrum of aggressive cancers (including CRPC), and the challenges associated with inhibition of c-Myc (because of its non-enzymatic nature), our novel findings of selective killing, and blockade of invasive and soft-agar colony-forming abilities of the castration-resistant, bone-metastatic C4-2B prostate cancer cells by MK591, open up a new avenue to attack CRPC cells for better management of advanced prostate cancer while sparing normal, non-cancer body cells.     

Monoclonal antibody targeting of N-cadherin inhibits prostate cancer growth, metastasis and castration resistance

The transition from androgen-dependent to castration-resistant prostate cancer (CRPC) is a lethal event of uncertain molecular etiology. Comparing gene expression in isogenic androgen-dependent and CRPC xenografts, we found a reproducible increase in N-cadherin expression, which was also elevated in primary and metastatic tumors of individuals with CRPC. Ectopic expression of N-cadherin in nonmetastatic, androgen-dependent prostate cancer models caused castration resistance, invasion and metastasis. Monoclonal antibodies against the ectodomain of N-cadherin reduced proliferation, adhesion and invasion of prostate cancer cells in vitro. In vivo, these antibodies slowed the growth of multiple established CRPC xenografts, blocked local invasion and metastasis and, at higher doses, led to complete regression. N-cadherin-specific antibodies markedly delayed the time to emergence of castration resistance, markedly affected tumor histology and angiogenesis, and reduced both AKT serine-threonine kinase activity and serum interleukin-8 (IL-8) secretion. These data indicate that N-cadherin is a major cause of both prostate cancer metastasis and castration resistance. Therapeutic targeting of this factor with monoclonal antibodies may have considerable clinical benefit.     

Steroidogenesis inhibitors alter but do not eliminate androgen synthesis mechanisms during progression to castration-resistance in LNCaP prostate xenografts

In castration-resistant prostate cancer (CRPC) many androgen-regulated genes become re-expressed and tissue androgen levels increase despite low serum levels. We and others have recently reported that CRPC tumor cells can de novo synthesize androgens from adrenal steroid precursors or cholesterol and that high levels of progesterone exist in LNCaP tumors after castration serving perhaps as an intermediate in androgen synthesis.Herein, we compare androgen synthesis from [³H-progesterone] in the presence of specific steroidogenesis inhibitors and anti-androgens in steroid starved LNCaP cells and CRPC tumors. Similarly, we compare steroid profiles in LNCaP tumors at different stages of CRPC progression.Steroidogenesis inhibitors targeting CYP17A1 and SRD5A2 significantly altered but did not eliminate androgen synthesis from progesterone in steroid starved LNCaP cells and CRPC tumors. Upon exposure to inhibitors of steroidogenesis prostate cancer cells adapt gradually during CRPC progression to synthesize DHT in a compensatory manner through alternative feed-forward mechanisms. Furthermore, tumors obtained immediately after castration are significantly less efficient at metabolizing progesterone (36%) and produce a different steroid profile to CRPC tumors. Optimal targeting of the androgen axis may be most effective when tumors are least efficient at synthesizing androgens. Confirmatory studies in humans are required to validate these findings.     

Cotargeting Polo-Like Kinase 1 and the Wnt/β-Catenin Signaling Pathway in Castration-Resistant Prostate Cancer

The Wnt/β-catenin signaling pathway has been identified as one of the predominantly upregulated pathways in castration-resistant prostate cancer (CRPC). However, whether targeting the β-catenin pathway will prove effective as a CRPC treatment remains unknown. Polo-like kinase 1 (Plk1) is a critical regulator in many cell cycle events, and its level is significantly elevated upon castration of mice carrying xenograft prostate tumors. Indeed, inhibition of Plk1 has been shown to inhibit tumor growth in several in vivo studies. Here, we show that Plk1 is a negative regulator of Wnt/β-catenin signaling. Plk1 inhibition or depletion enhances the level of cytosolic and nuclear β-catenin in human prostate cancer cells. Furthermore, inhibition of Wnt/β-catenin signaling significantly potentiates the antineoplastic activity of the Plk1 inhibitor BI2536 in both cultured prostate cancer cells and CRPC xenograft tumors. Mechanistically, axin2, a negative regulator of the β-catenin pathway, serves as a substrate of Plk1, and Plk1 phosphorylation of axin2 facilitates the degradation of β-catenin by enhancing binding between glycogen synthase kinase 3β (GSK3β) and β-catenin. Plk1-phosphorylated axin2 also exhibits resistance to Cdc20-mediated degradation. Overall, this study identifies a novel Plk1-Wnt signaling axis in prostate cancer, offering a promising new therapeutic option to treat CRPC.     

The Hippo Pathway Effector YAP Regulates Motility,Invasion, and Castration-Resistant Growth of Prostate Cancer Cells

Yes-associated protein (YAP) is an effector of the Hippo tumor suppressor pathway. The functional significance of YAP in prostate cancer has remained elusive. In this study, we first show that enhanced expression of YAP is able to transform immortalized prostate epithelial cells and promote migration and invasion in both immortalized and cancerous prostate cells. We found that YAP mRNA was upregulated in androgen-insensitive prostate cancer cells (LNCaP-C81 and LNCaP-C4-2 cells) compared to the level in androgen-sensitive LNCaP cells. Importantly, ectopic expression of YAP activated androgen receptor signaling and was sufficient to promote LNCaP cells from an androgen-sensitive state to an androgen-insensitive state in vitro, and YAP conferred castration resistance in vivo. Accordingly, YAP knockdown greatly reduced the rates of migration and invasion of LNCaP-C4-2 cells and under androgen deprivation conditions largely blocked cell division in LNCaP-C4-2 cells. Mechanistically, we found that extracellular signal-regulated kinase–ribosomal s6 kinase signaling was downstream of YAP for cell survival, migration, and invasion in androgen-insensitive cells. Finally, immunohistochemistry showed significant upregulation and hyperactivation of YAP in castration-resistant prostate tumors compared to their levels in hormone-responsive prostate tumors. Together, our results identify YAP to be a novel regulator in prostate cancer cell motility, invasion, and castration-resistant growth and as a potential therapeutic target for metastatic castration-resistant prostate cancer (CRPC).     

Co(II)‐salen catalyzed stereoselective cyclopropanation of fluorinated styrenes

Three cis‐selective Co(II)‐salen complexes have been developed for the asymmetric cyclopropanation of para‐fluorinated styrenes with ethyl diazoacetate. Increasing the steric reach of the C₂‐symmetric ligand side chains improved the enantiomeric ratio of the reaction from 28:1 to 66:1. The methodology was exemplified by the gram‐scale synthesis of a lead compound for the treatment of castration‐resistant prostate cancer (CRPC), as well as a structurally related analog.     

Identification of CD166 as a Surface Marker for Enriching Prostate Stem/Progenitor and Cancer Initiating Cells

New therapies for late stage and castration resistant prostate cancer (CRPC) depend on defining unique properties and pathways of cell sub-populations capable of sustaining the net growth of the cancer. One of the best enrichment schemes for isolating the putative stem/progenitor cell from the murine prostate gland is Lin(-);Sca1(+);CD49f(hi) (LSC(hi)), which results in a more than 10-fold enrichment for in vitro sphere-forming activity. We have shown previously that the LSC(hi) subpopulation is both necessary and sufficient for cancer initiation in the Pten-null prostate cancer model. To further improve this enrichment scheme, we searched for cell surface molecules upregulated upon castration of murine prostate and identified CD166 as a candidate gene. CD166 encodes a cell surface molecule that can further enrich sphere-forming activity of WT LSC(hi) and Pten null LSC(hi). Importantly, CD166 could enrich sphere-forming ability of benign primary human prostate cells in vitro and induce the formation of tubule-like structures in vivo. CD166 expression is upregulated in human prostate cancers, especially CRPC samples. Although genetic deletion of murine CD166 in the Pten null prostate cancer model does not interfere with sphere formation or block prostate cancer progression and CRPC development, the presence of CD166 on prostate stem/progenitors and castration resistant sub-populations suggest that it is a cell surface molecule with the potential for targeted delivery of human prostate cancer therapeutics.     

Combined AKT and MEK Pathway Blockade in Pre-Clinical Models of Enzalutamide-Resistant Prostate Cancer

Despite recent improvements in patient outcomes using newer androgen receptor (AR) pathway inhibitors, treatment resistance in castrate resistant prostate cancer (CRPC) continues to remain a clinical problem. Co-targeting alternate resistance pathways are of significant interest to treat CRPC and delay the onset of resistance. Both the AKT and MEK signaling pathways become activated as prostate cancer develops resistance to AR-targeted therapies. This pre-clinical study explores co-targeting these pathways in AR-positive prostate cancer models. Using various in vitro models of prostate cancer disease states including androgen dependent (LNCaP), CRPC (V16D and 22RV1) and ENZ-resistant prostate cancer (MR49C and MR49F), we evaluate the relevance of targeting both AKT and MEK pathways. Our data reveal that AKT inhibition induces apoptosis and inhibits cell growth in PTEN null cell lines independently of their sensitivity to hormone therapy; however, AKT inhibition had no effect on the PTEN positive 22RV1 cell line. Interestingly, we found that MEK inhibition had greater effect on 22RV1 cells compared to LNCaP, V16D or ENZ-resistant cells MR49C and MR49F cells. In vitro, combination AKT and MEK blockade had evidence of synergy observed in some cell lines and assays, but this was not consistent across all results. In vivo, the combination of AKT and MEK inhibition resulted in more consistent tumor growth inhibition of MR49F xenografts and longer disease specific survival compared to AKT inhibitor monotherapy. As in our in vitro study, 22RV1 xenografts were more resistant to AKT inhibition while they were more sensitive to MEK inhibition. Our results suggest that targeting AKT and MEK in combination may be a valuable strategy in prostate cancer when both pathways are activated and further support the importance of characterizing the dominant oncogenic pathway in each patient’s tumor in order to select optimal therapy.     

De-implementation of low value castration for men with prostate cancer: protocol for a theory-based,mixed methods approach to minimizing low value androgen deprivation therapy (DeADT)

Background

Men with prostate cancer are often castrated with long-acting injectable drugs termed androgen deprivation therapy (ADT). Although many benefit, ADT is also used in patients with little or nothing to gain. The best ways to stop this practice are unknown, and range from blunt pharmacy restrictions to informed decision-making. This study will refine and pilot two different de-implementation strategies for reducing ADT use among those unlikely to benefit in preparation for a comparative effectiveness trial.

Methods/design

This innovative mixed methods research program has three aims. Aim 1: To assess preferences and barriers for de-implementation of chemical castration in prostate cancer. Guided by the theoretical domains framework (TDF), urologists and patients from facilities with the highest and lowest castration rates across the VA will be interviewed to identify key preferences and de-implementation barriers for reducing castration as prostate cancer treatment. This qualitative work will inform Aim 2 while gathering rich information for two proposed pilot intervention strategies. Aim 2: To use a discrete choice experiment (DCE), a novel barrier prioritization approach, for de-implementation strategy tailoring. The investigators will conduct national surveys of urologists to prioritize key barriers identified in Aim 1 for stopping incident castration as localized prostate cancer treatment using a DCE experiment design. These quantitative results will identify the most important barriers to be addressed through tailoring of two pilot de-implementation strategies in preparation for Aim 3 piloting. Aim 3: To pilot two tailored de-implementation strategies to reduce castration as localized prostate cancer treatment. Building on findings from Aims 1 and 2, two de-implementation strategies will be piloted. One strategy will focus on formulary restriction at the organizational level and the other on physician/patient informed decision-making at different facilities. Outcomes will include acceptability, feasibility, and scalability in preparation for an effectiveness trial comparing these two widely varying de-implementation strategies.

Discussion

Our innovative approach to de-implementation strategy development is directly aligned with state-of-the-art complex implementation intervention development and implementation science. This work will broadly advance de-implementation science for low value cancer care, and foster participation in our de-implementation evaluation trial by addressing barriers, facilitators, and concerns through pilot tailoring.

Trial registration

ClinicalTrials.gov Identifier: NCT03579680, First Posted July 6, 2018.

     

Survival and clinical metastases among prostate cancer patients treated with androgen deprivation therapy in Sweden

ObjectivesTo examine the incidence of metastases and clinical course of prostate cancer patients who are without confirmed metastasis when initiating androgen deprivation therapy (ADT).MethodsRetrospective cohort study conducted using electronic medical records from Swedish outpatient urology clinics linked to national mandatory registries to capture medical and demographic data. Prostate cancer patients initiating ADT between 2000 and 2010 were followed from initiation of ADT to metastasis, death, and/or end of follow-up.ResultsThe 5-year cumulative incidence (CI) of metastasis was 18%. Survival was 60% after 5 years; results were similar for bone metastasis-free survival. The 5-year CI of castration-resistant prostate cancer (CRPC) was 50% and the median survival from CRPC development was 2.7 years. Serum prostate-specific antigen (PSA) levels and PSA doubling time were strong predictors of bone metastasis, any metastasis, and death.ConclusionThis study provides understanding of the clinical course of prostate cancer patients without confirmed metastasis treated with ADT in Sweden. Greater PSA values and shorter PSA doubling time (particularly ≤ 6 months) were associated with increased risk of bone metastasis, any metastasis, and death.     

Thioredoxin Reductase 1 Expression and Castration-recurrent Growth of Prostate Cancer

INTRODUCTION: Many genes are differentially expressed between androgen-dependent and androgen-independent prostate cancer (CaP). Differential expression analysis and subtractive hybridization previously identified nine genes expressed in intact mice bearing CWR22 tumors and castrated mice bearing recurrent CWR22 tumors but not in regressed tumors. The objectives of this study were to develop an immunostaining method to dual-label foci of proliferating tumor cells [the origin of castration-recurrent CaP (CR-CaP)], to determine which of the nine candidate proteins were differentially expressed in proliferating versus nonproliferating cells at the onset of growth after castration, and to test preclinical findings using clinical specimens of androgen-stimulated benign prostate (AS-BP) and CaP (AS-CaP) and CR-CaP. METHODS: Paraffin-embedded, bromodeoxyuridine-injected CWR22 tumors were hydrated, antigen-retrieved using high heat and high pressure, labeled for each of the nine antigens of interest, visualized using peroxidase, and counterstained with hematoxylin. Mean optical density was calculated for proliferating and nonproliferating areas using automated (nuclear staining) or manual (cytoplasmic staining) image analysis. Prostate tissue microarray sections were immunostained and visually scored. RESULTS: Immunohistochemistry revealed higher nuclear expression of thioredoxin reductase 1 (TrxR1) in proliferating cells than nonproliferating cells (P < .005). There were no statistical differences between cell types in the expression of other proteins. TrxR1 expression was higher (P < .01) in CR-CaP compared with AS-BP or AS-CaP. CONCLUSIONS: Increased TrxR1 expression in CR-CaP was consistent with increased TrxR1 and BrdU expression at the onset of growth in the CWR22 model. Thioredoxin reductase 1 should be targeted in an attempt to delay or prevent CaP recurrence after castration.     

Incidence of bone metastases in breast cancer patients in the United Kingdom: Results of a multi-database linkage study using the general practice research database

BackgroundBone is a frequent site for metastases among women with breast cancer. We conducted a study using the General Practice Research Database (GPRD), with linkage to the National Cancer Registry (NCR) and Hospital Episode Statistics (HES), to estimate the incidence of bone metastases in women with breast cancer in the United Kingdom.MethodsWe identified all women in the GPRD aged 20–99 with a first-time diagnosis of breast cancer between 2000 and 2006. To address potential underreporting, we developed and validated an algorithm to serve as a proxy for bone metastases. Bone metastases were defined as (1) a bone cancer diagnosis code on the same day or following breast cancer diagnosis date, or (2) another metastasis code plus codes consistent with bone metastases diagnosis or treatment using the algorithm. We sent questionnaires to a sample of general practitioners to validate these definitions.ResultsWe included 13,207 breast cancer patients (median age at diagnosis of 61 years) who contributed 70,885 person-years of follow-up. The majority of patients had stage 1 or 2 breast cancer (90.4%), and 2.6% had metastatic breast cancer at diagnosis. We identified 788 women (6.0%) with bone metastases after a median follow-up of 5.4 years. Questionnaire results validated the diagnosis of bone metastases in 88% of patients with a bone cancer code and for 70% identified with the algorithm.ConclusionThis is the first time the GPRD has been linked to HES and NCR to study the epidemiology of bone metastases, adding important information on the burden of bone metastasis.