Histopathologically Validated Diagnostic Accuracy of PSMA-PET/CT in the Primary and Secondary Staging of Prostate Cancer and the Impact of PSMA-PET/CT on Clinical Management: A Systematic Review and Meta-analysis.

Prostate-specific membrane antigen (PSMA) is a highly expressed protein in prostate cancer (PCa) and has become an increasingly popular target for molecular imaging in recent years. PSMA based positron-emission-tomography/computed tomography (PET/CT) is a well characterised hybrid imaging modality that combines the high sensitivity of PET with the high spatial resolution of CT imaging. The combination of these two imaging modalities provides an accurate tool for detecting and managing PCa. Several diagnostic accuracy and clinical management studies investigating the role of PSMA PET/CT in PCa have been published recently. This study aimed to perform an updated systematic review and meta-analysis to evaluate the diagnostic performance of PSMA PET/CT in localised, lymph node metastatic (LNM) and recurrent PCa patients and assess its impact on the clinical management of primary and recurrent PCa. Using Medline, Embase, PubMed and Cochrane Library databases, studies reporting the diagnostic accuracy and clinical management of PSMA PET/CT were analysed based on the PRISMA guidelines. Statistical analyses were conducted using random-effects models, and meta-regression explored observed heterogeneity. Results indicate that the sensitivity and specificity of PSMA PET/CT for localised PCa were 71.0% (95% confidence interval (CI): 58.0, 81.0) and 92.0% (95% CI: 86.0, 96.0), respectively (N = 10; n = 404 patients). Sensitivity and specificity in LNM were 57.0% (95% CI: 49.0, 64.0) and 96.0% (95% CI: 95.0, 97.0) (N = 36; n = 3,659 patients). For patients with biochemical recurrence (BCR), sensitivity was 84.0% (95% CI: 74.0, 90.0), and specificity was 97.0% (95% CI: 88.0, 99.0) (N = 9; n = 818 patients). The pooled proportion of management changes in primary (N = 16; n = 1,099 patients) and recurrent (N = 40; n = 5,398 patients) PCa was 28.0% (95% CI: 23.0, 34.0) and 54.0% (95% CI: 50.0, 58.0), respectively. In conclusion, PSMA PET/CT shows moderate sensitivity and high specificity in localised and LNM disease, while the accuracy in BCR patients was high. PSMA PET/CT also had a large impact on the clinical management of PCa patients. This is the most extensive and first systematic review to include three subgroups of PCa with histologically verified diagnostic accuracy and clinical management change reported separately in primary and recurrent disease settings.

Barriers and facilitators to implementing priority setting and resource allocation tools in hospital decisions: A systematic review.

Health care budgets in high-income countries are having issues coping with unsustainable growth in demand, particularly in the hospital setting. Despite this, implementing tools systematising priority setting and resource allocation decisions has been challenging. This study answers two questions: (1) what are the barriers and facilitators to implementing priority setting tools in the hospital setting of high-income countries? and (2) what is their fidelity? A systematic review using the Cochrane methods was conducted including studies of hospital-related priority setting tools reporting barriers or facilitators for implementation, published after the year 2000. Barriers and facilitators were classified using the Consolidated Framework for Implementation Research (CFIR). Fidelity was assessed using priority setting tool's standards. Out of thirty studies, ten reported program budgeting and marginal analysis (PBMA), twelve multi-criteria decision analysis (MCDA), six health technology assessment (HTA) related frameworks, and two, an ad hoc tool. Barriers and facilitators were outlined across all CFIR domains. Implementation factors not frequently observed, such as 'evidence of previous successful tool application', 'knowledge and beliefs about the intervention' or 'external policy and incentives' were reported. Conversely, some constructs did not yield any barrier or facilitator including 'intervention source' or 'peer pressure'. PBMA studies satisfied the fidelity criteria between 86% and 100%, for MCDA it varied between 36% and 100%, and for HTA it was between 27% and 80%. However, fidelity was not related to implementation. This study is the first to use an implementation science approach. Results represent the starting point for organisations wishing to use priority setting tools in the hospital setting by providing an overview of barriers and facilitators. These factors can be used to assess readiness for implementation or to serve as the foundation for process evaluations. Through our findings, we aim to improve the uptake of priority setting tools and support their sustainable use.

Patient Preferences in Targeted Pharmacotherapy for Cancers: A Systematic Review of Discrete Choice Experiments.

BACKGROUND: Targeted pharmacotherapy has been increasingly applied in cancer treatment due to its breakthroughs. However, the unmet needs of cancer patients are still significant, highlighting the urgency to investigate patient preferences. It is unclear how patients deliberate their choices between different aspects of targeted therapy, including cost, efficacy, and adverse events. Since discrete choice experiments (DCEs) have been widely applied to patient preference elicitation, we reviewed DCEs on targeted therapy for different cancers. We also synthesized evidence on the factors influencing patients' choices and their willingness-to-pay (WTP) for survival when treated by targeted therapy. METHODS: We searched databases, including PubMed, EMBASE and MEDLINE, up to August 16, 2022, supplemented by a reference screening. The attributes from the selected studies were categorized into three groups: outcomes, costs, and process. We also calculated the relative importance of attributes and WTP for survival whenever possible. The purpose, respondents, explanation, findings, significance (PREFS) checklist was used to evaluate the quality of the included DCE studies. RESULTS: The review identified 34 eligible studies from 13 countries covering 14 cancers, such as breast, ovarian, kidney, prostate, and skin cancers. It also reveals a rising trend of DCEs on this topic, as most studies were published after 2018. We found that patients placed higher weights on the outcome (e.g., overall survival) and cost attributes than on process attributes. On average, patients were willing to pay $561 (95% confidence interval [CI]: $415-$758) and $716 (95% CI $524-$958) out-of-pocket for a 1-month increase in progression-free survival and overall survival, respectively. PREFS scores of the 34 studies ranged from 2 to 4, with a mean of 3.38 (SD: 0.65), suggesting a reasonable quality based on the checklist. However, most studies (n = 32, 94%) did not assess the impact of non-responses on the results. CONCLUSIONS: This is the first systematic review focusing on patient preferences for targeted cancer therapy. We showcased novel approaches for evidence synthesis of DCE results, especially the attribute relative importance and WTP. The results may inform stakeholders about patient preferences toward targeted therapy and their WTP estimates. More studies with improved study design and quality are warranted to generate more robust evidence to assist decision making.

Microcosting Study of Prostate-Specific Membrane Antigen Positron Emission Tomography/Computed Tomography in Prostate Cancer.

OBJECTIVES: Prostate-specific membrane antigen (PSMA) positron emission tomography/computed tomography (PET/CT) has emerged as a promising imaging tool in prostate cancer diagnosis. PSMA PET/CT radiotracers are produced in-house (gallium-68, eg, 68Ga-PSMA-11) or provided by commercial entities (fluorine-18, eg, 18F-DCFPyL). Nevertheless, the cost per procedure is not well established given that current estimates have several limitations. This study aimed to establish the cost of PSMA PET/CT in Australia. METHODS: Hospitals and diagnostic facilities currently conducting PSMA PET/CT in Australia in metropolitan and regional areas completed a survey of PSMA PET/CT throughput, radiotracers involved, and the cost of assets, departmental staffing, consumables, and occupancy. Total costs were estimated using a top-down microcosting approach, involving identifying all relevant cost components and valuing each component for the average patient, and a gross costing approach, involving apportioning cost components at an aggregated level. RESULTS: Data were collected from 8 facilities. The most common radiotracer used was 18F-DCFPyL (7 facilities, 87%), followed by 68Ga-PSMA-11 (4 facilities, 50%). The average cost of PSMA PET/CT was A$1554.77 and A$1306.00 based on the microcosting and gross costing approaches, respectively. CONCLUSIONS: This study provides a detailed and accurate estimation of the cost of PSMA PET/CT in Australia. These costs can be used as a benchmark to identify potential efficiencies and help policy makers set the appropriate reimbursement rate for this procedure. The use of data from facilities using different radiotracers in metropolitan and regional areas and with different throughput increases the generalizability of the results, especially in countries with similar health systems.

Cost-Effectiveness Analysis of Prostate-Specific Membrane Antigen (PSMA) Positron Emission Tomography/Computed Tomography (PET/CT) for the Primary Staging of Prostate Cancer in Australia.

BACKGROUND AND OBJECTIVES: Prostate-specific membrane antigen (PSMA) positron emission tomography (PET) combined with computed tomography (CT) is a new imaging modality to detect the extra-prostatic spread of prostate cancer. PSMA PET/CT has a higher sensitivity and specificity than conventional imaging (CT ± whole body bone scan [WBBS]). This study conducted a cost-utility analysis of PSMA PET/CT compared with conventional imaging for patients with newly diagnosed, intermediate-risk or high-risk primary prostate cancer. PERSPECTIVE: Australian healthcare perspective. SETTING: Tertiary. METHODS: A decision-analytic Markov model combined data from a variety of sources. The time horizon was 35 years. The sensitivity and specificity of PSMA PET/CT and CT alone were based on meta-analyses and the test accuracy of CT+WBBS was based on a single randomised controlled trial. Health outcomes included cases detected, life-years, and quality-adjusted life-years. Costs related to other diagnostic tests, initial treatment, adverse events, and post-disease progression were included. All costs were reported in 2021 Australian Dollars (A$). RESULTS: The deterministic incremental cost-effectiveness ratio of PSMA PET/CT was estimated to be A $21,147/quality-adjusted life-year gained versus CT+WBBS, and A$36,231/quality-adjusted life-year gained versus CT alone. The results were most sensitive to the time horizon, and the initial treatments received by patients diagnosed with metastatic cancer. The probability of PSMA PET/CT being cost effective was estimated to be 91% versus CT+WBBS and 89% versus CT alone, using a threshold of AU$50,000/quality-adjusted life-year gained. CONCLUSIONS: PSMA PET/CT is likely to be more costly than CT+WBBS or CT alone in Australia; however, it is still likely to be considered cost effective compared with conventional imaging.

Using Australian panel data to account for unobserved factors in measuring inequities for different channels of healthcare utilization.

Inequity in healthcare utilization is typically measured as the unequal distribution of services by observable non-need indicators, such as income, after controlling for observable need indicators. However, important sources of unequal healthcare utilization are often unobserved. The unobserved element may reflect need factors, such as imperfectly measured severity of illness, that would predict greater utilization across different healthcare channels, but also based on choice, such as patient preferences to use a particular healthcare channel over an alternative one, which may differ in its effect between channels. Accounting for unobserved sources of utilization may, therefore, help to understand contradictory inequalities between different healthcare channels, such as pro-poor inequalities for general practitioner use and pro-rich inequalities for specialist visits. This paper uses survey data from the Household Income and Labour Dynamics in Australia and panel data methods to investigate if seemingly contradictory inequalities between different healthcare channels are explained by latent individual-level heterogeneity. Results show that unobserved individual-level heterogeneity affects inequities across different healthcare channels, providing indications that the unobserved element may primarily represent unobserved need.

Allele-Specific MicroRNA-Mediated Regulation of a Glycolysis Gatekeeper PDK1 in Cancer Metabolism.

BACKGROUND: Emerging evidence has revealed that genetic variations in microRNA (miRNA) binding sites called miRSNPs can alter miRNA binding in an allele-specific manner and impart prostate cancer (PCa) risk. Two miRSNPs, rs1530865 (G > C) and rs2357637 (C > A), in the 3' untranslated region of pyruvate dehydrogenase kinase 1 (PDK1) have been previously reported to be associated with PCa risk. However, these results have not been functionally validated. METHODS: In silico analysis was used to predict miRNA-PDK1 interactions and was tested using PDK1 knockdown, miRNA overexpression and reporter gene assay. RESULTS: PDK1 expression was found to be upregulated in PCa metastasis. Further, our results show that PDK1 suppression reduced the migration, invasion, and glycolysis of PCa cells. Computational predictions showed that miR-3916, miR-3125 and miR-3928 had a higher binding affinity for the C allele than the G allele for the rs1530865 miRSNP which was validated by reporter gene assays. Similarly, miR-2116 and miR-889 had a higher affinity for the A than C allele of the rs2357637 miRSNP. Overexpression of miR-3916 and miR-3125 decreased PDK1 protein levels in cells expressing the rs1530865 SNP C allele, and miR-2116 reduced in cells with the rs2357637 SNP A allele. CONCLUSIONS: The present study is the first to report the regulation of the PDK1 gene by miRNAs in an allele-dependent manner and highlights the role of PDK1 in metabolic adaption associated with PCa progression.

Targeted beta therapy of prostate cancer with 177Lu-labelled Miltuximab® antibody against glypican-1 (GPC-1).

PURPOSE: Chimeric antibody Miltuximab®, a human IgG1 engineered from the parent antibody MIL-38, is in clinical development for solid tumour therapy. Miltuximab® targets glypican-1 (GPC-1), a cell surface protein involved in tumour growth, which is overexpressed in solid tumours, including prostate cancer (PCa). This study investigated the potential of 89Zr-labelled Miltuximab® as an imaging agent, and 177Lu-labelled Miltuximab® as a targeted beta therapy, in a mouse xenograft model of human prostate cancer. METHODS: Male BALB/c nude mice were inoculated subcutaneously with GPC-1-positive DU-145 PCa cells. In imaging and biodistribution studies, mice bearing palpable tumours received (a) 2.62 MBq [89Zr]Zr-DFO-Miltuximab® followed by PET-CT imaging, or (b) 6 MBq [177Lu]Lu-DOTA-Miltuximab® by Cerenkov imaging, and ex vivo assessment of biodistribution. In an initial tumour efficacy study, mice bearing DU-145 tumours were administered intravenously with 6 MBq [177Lu]Lu-DOTA-Miltuximab® or control DOTA-Miltuximab® then euthanised after 27 days. In a subsequent survival efficacy study, tumour-bearing mice were given 3 or 10 MBq of [177Lu]Lu-DOTA-Miltuximab®, or control, and followed up to 120 days. RESULTS: Antibody accumulation in DU-145 xenografts was detected by PET-CT imaging using [89Zr]Zr-DFO-Miltuximab® and confirmed by Cerenkov luminescence imaging post injection of [177Lu]Lu-DOTA-Miltuximab®. Antibody accumulation was higher (% IA/g) in tumours than other organs across multiple time points. A single injection with 6 MBq of [177Lu]Lu-DOTA-Miltuximab® significantly inhibited tumour growth as compared with DOTA-Miltuximab® (control). In the survival study, mice treated with 10 MBq [177Lu]Lu-DOTA-Miltuximab® had significantly prolonged survival (mean 85 days) versus control (45 days), an effect associated with increased cancer cell apoptosis. Tissue histopathology assessment showed no abnormalities associated with [177Lu]Lu-DOTA-Miltuximab®, in line with other observations of tolerability, including body weight stability. CONCLUSION: These findings demonstrate the potential utility of Miltuximab® as a PET imaging agent ([89Zr]Zr-DFO-Miltuximab®) and a beta therapy ([177Lu]Lu-DOTA-Miltuximab®) in patients with PCa or other GPC-1 expressing tumours.

Interleukin (IL)-22 from IL-20 Subfamily of Cytokines Induces Colonic Epithelial Cell Proliferation Predominantly through ERK1/2 Pathway.

The interleukin (IL)-20 subfamily of cytokines consists of IL-19, IL-20, IL-22, IL-24, and IL-26, and the expression of IL-20, IL-22, and IL-24 is reported to be higher in the colon of patients with ulcerative colitis. Although the receptors for these cytokines are highly expressed in the colon epithelium, their effects on epithelial renewal are not clearly understood. This study evaluated the effects of IL-20, IL-22, and IL-24 in epithelial renewal using the LS174T human colon cancer epithelial cell line. LS174T cells were treated with IL-20, IL-22, and IL-24 (25, 50, and 100 ng/mL) and a live-cell imaging system was used to evaluate the effects on cell proliferation. Following treatment, the signaling pathways contributing to cell proliferation were investigated through Western blotting in LS174T cells and downstream transcriptional changes through qRT-PCR in LS174T cells, and RNA-Seq in primary murine intestinal epithelial cells. Our results demonstrated that only IL-22 promoted LS174T cell proliferation, mediated via extracellular-signal-regulated kinase (ERK)1/2-mediated downstream regulation of p90RSK, c-Jun, and transcriptional changes of TRIM15 and STOM. IL-22 also promoted expression of ERK1/2-independent genes such as DDR2, LCN2, and LRG1, which are known to be involved in cell proliferation and migration. This study suggests that IL-22 induces cell proliferation in highly proliferative cells such as intestinal epithelial cells.

Emergence of MicroRNAs as Key Players in Cancer Cell Metabolism.

BACKGROUND: Metabolic reprogramming is a hallmark of cancer. MicroRNAs (miRNAs) have been found to regulate cancer metabolism by regulating genes involved in metabolic pathways. Understanding this layer of complexity could lead to the development of novel therapeutic approaches. CONTENT: miRNAs are noncoding RNAs that have been implicated as master regulators of gene expression. Studies have revealed the role of miRNAs in the metabolic reprogramming of tumor cells, with several miRNAs both positively and negatively regulating multiple metabolic genes. The tricarboxylic acid (TCA) cycle, aerobic glycolysis, de novo fatty acid synthesis, and altered autophagy allow tumor cells to survive under adverse conditions. In addition, major signaling molecules, hypoxia-inducible factor, phosphatidylinositol-3 kinase/protein kinase B/mammalian target of rapamycin/phosphatase and tensin homolog, and insulin signaling pathways facilitate metabolic adaptation in tumor cells and are all regulated by miRNAs. Accumulating evidence suggests that miRNA mimics or inhibitors could be used to modulate the activity of miRNAs that drive tumor progression via altering their metabolism. Currently, several clinical trials investigating the role of miRNA-based therapy for cancer have been launched that may lead to novel therapeutic interventions in the future. SUMMARY: In this review, we summarize cancer-related metabolic pathways, including glycolysis, TCA cycle, pentose phosphate pathway, fatty acid metabolism, amino acid metabolism, and other metabolism-related oncogenic signaling pathways, and their regulation by miRNAs that are known to lead to tumorigenesis. Further, we discuss the current state of miRNA therapeutics in the clinic and their future potential.

MicroRNA-3162-5p-Mediated Crosstalk between Kallikrein Family Members Including Prostate-Specific Antigen in Prostate Cancer.

BACKGROUND: MicroRNAs mediate biological processes through preferential binding to the 3' untranslated region (3' UTR) of target genes. Studies have shown their association with prostate cancer (PCa) risk through single-nucleotide polymorphisms (SNPs), known as miRSNPs. In a European cohort, 22 PCa risk-associated miRSNPs have been identified. The most significant miRSNP in the 3' UTR of Kallikrein-related peptidase 3 (KLK3) created a binding site for miR-3162-5p. Here we investigated the miR-3162-5p-KLK interaction and the clinical implication of miR-3162-5p in PCa. METHODS: We tested the role of miR-3162-5p in PCa etiology using IncuCyte live-cell imaging and anchorage-independent growth assays. The effect of miR-3162-5p on KLK and androgen receptor (AR) expression was measured by RT-quantitative (q)PCR and target pulldown assays. KLK3 proteolytic activity was determined by DELFIA® immunoassay. Mass spectrometry identified pathways affected by miR-3162-5p. miR-3162-5p expression was measured in clinical samples using RT-qPCR. RESULTS: miR-3162-5p affected proliferation, migration, and colony formation of LNCaP cells by regulating the expression of KLK2-4 and AR by direct targeting. KLK3 protein expression was regulated by miR-3162-5p consistent with lower KLK3 proteolytic activity observed in LNCaP-conditioned media. KLK/AR pulldown and mass spectrometry analysis showed a potential role of miR-3162-5p in metabolic pathways via KLK/AR and additional targets. Increased miR-3162-5p expression was observed in prostate tumor tissues with higher Gleason grade. CONCLUSIONS: Our study provides an insight into possible involvement of miR-3162-5p in PCa etiology by targeting KLKs and AR. It highlights clinical utility of miR-3162-5p and its interactive axis as a new class of biomarkers and therapeutic targets for PCa.

A Plasma Biomarker Panel of Four MicroRNAs for the Diagnosis of Prostate Cancer.

Prostate cancer is diagnosed in over 1 million men every year globally, yet current diagnostic modalities are inadequate for identification of significant cancer and more reliable early diagnostic biomarkers are necessary for improved clinical management of prostate cancer patients. MicroRNAs (miRNAs) modulate important cellular processes/pathways contributing to cancer and are stably present in body fluids. In this study we profiled 372 cancer-associated miRNAs in plasma collected before (~60% patients) and after/during commencement of treatment (~40% patients), from age-matched prostate cancer patients and healthy controls, and observed elevated levels of 4 miRNAs - miR-4289, miR-326, miR-152-3p and miR-98-5p, which were validated in an independent cohort. The miRNA panel was able to differentiate between prostate cancer patients and controls (AUC = 0.88). Analysis of published miRNA transcriptomic data from clinical samples demonstrated low expression of miR-152-3p in tumour compared to adjacent non-malignant tissues. Overexpression of miR-152-3p increased proliferation and migration of prostate cancer cells, suggesting a role for this miRNA in prostate cancer pathogenesis, a concept that was supported by pathway analysis of predicted miR-152-3p target genes. In summary, a four miRNA panel, including miR-152-3p which likely targets genes with key roles in prostate cancer pathogenesis, has the potential to improve early prostate cancer diagnosis.

MicroRNAs in HPV associated cancers: small players with big consequences.

INTRODUCTION: MicroRNAs (miRs) are short (~20 nucleotides) non-coding ribonuecleic acids (ncRNAs) known to be involved in cellular processes such as proliferation, differentiation, immune response, pathogenicity and tumourigenesis, among many others. The regulatory mechanisms exerted by miRs have been implicated in many cancers, including Human Papillomavirus (HPV)-associated cancers. Areas covered: In this review, the authors discuss the involvement of miRs (-143, -375, -21, -200, -296 etc.) that have been shown to be dysregulated in HPV-associated cancers. This review also encompasses both intracellular and exosomal miRs, and their potential as diagnostic biomarkers in saliva and blood. The authors have also attempted to dissect the functional impact of miRs on cellular processes such as changes in cellular polarity, loss of apoptosis and tumour suppression, and unchecked and uncontrolled cell cycle regulation, all of which ultimately lead to aberrant cellular proliferation. Expert commentary: Identification of dysregulated miRs in HPV-associated cancers opens up new opportunities to develop diagnostic, therapeutic and prognostic biomarkers. Studies on global expression patterns of miRs dysregulated in HPV-associated cancers can be instrumental in developing broader therapeutic strategies. Therapies like anti-miR, miR-replacement and those based on alternative natural products targeting miRs, need to be improved and better synchronized to be cost-effective and have better treatment outcomes.

MicroRNA Theranostics in Prostate Cancer Precision Medicine.

BACKGROUND: Prostate cancer is the second most frequently diagnosed cancer in men worldwide. Theranostics, a combination of diagnostics and therapeutics, is an emerging concept in the field of precision medicine, and microRNAs (miRNAs) are predictive pioneers in this area. CONTENT: miRNAs are small endogenous noncoding RNA molecules that regulate gene expression posttranscriptionally by targeting messenger RNAs. More than 60% of all protein coding genes are controlled by miRNAs, which makes them powerful regulators of the different cellular processes involved in the pathogenesis of various types of cancer, including prostate cancer. Growing evidence indicates the differential expression of miRNAs in tumor tissues. In addition, miRNAs in body fluids, known as circulating miRNAs, are present in remarkably stable forms and their alteration in prostate cancer has been well documented. Circulating miRNAs are known to originate from tumor tissues, thereby enabling intercellular communication via carriers to promote tumorigenesis and malignancy. In addition, fueled by recent advances, the use of miRNA-based anticancer therapies has been proposed with the onset of early phase clinical trials to assess the therapeutic efficacy of miRNAs. SUMMARY: In this review, we summarize the theranostic utility of miRNAs and outline their diagnostic and prognostic potential in prostate cancer. In addition, we discuss the current detection methodologies and emerging innovative strategies for the detection of miRNAs in body fluids and tumor tissues in the clinical setting. We also provide insight into the current and future therapeutic potential of miRNAs in prostate cancer.

Identification of a novel fusion transcript between human relaxin-1 (RLN1) and human relaxin-2 (RLN2) in prostate cancer.

Simultaneous expression of highly homologous RLN1 and RLN2 genes in prostate impairs their accurate delineation. We used PacBio SMRT sequencing and RNA-Seq in LNCaP cells in order to dissect the expression of RLN1 and RLN2 variants. We identified a novel fusion transcript comprising the RLN1 and RLN2 genes and found evidence of its expression in the normal and prostate cancer tissues. The RLN1-RLN2 fusion putatively encodes RLN2 isoform with the deleted secretory signal peptide. The identification of the fusion transcript provided information to determine unique RLN1-RLN2 fusion and RLN1 regions. The RLN1-RLN2 fusion was co-expressed with RLN1 in LNCaP cells, but the two gene products were inversely regulated by androgens. We showed that RLN1 is underrepresented in common PCa cell lines in comparison to normal and PCa tissue. The current study brings a highly relevant update to the relaxin field, and will encourage further studies of RLN1 and RLN2 in PCa and broader.

Differential uptake and cross-presentation of soluble and necrotic cell antigen by human DC subsets.

Cross-presentation is the mechanism by which exogenous Ag is processed for recognition by CD8(+) T cells. Murine CD8α(+) DCs are specialized at cross-presenting soluble and cellular Ag, but in humans this process is poorly characterized. In this study, we examined uptake and cross-presentation of soluble and cellular Ag by human blood CD141(+) DCs, the human equivalent of mouse CD8α(+) DCs, and compared them with human monocyte-derived DCs (MoDCs) and blood CD1c(+) DC subsets. MoDCs were superior in their capacity to internalize and cross-present soluble protein whereas CD141(+) DCs were more efficient at ingesting and cross-presenting cellular Ag. Whilst cross-presentation by CD1c(+) DCs and CD141(+) DCs was dependent on the proteasome, and hence cytosolic translocation, cross-presentation by MoDCs was not. Inhibition of endosomal acidification enhanced cross-presentation by CD1c(+) DCs and MoDCs but not by CD141(+) DCs. These data demonstrate that CD1c(+) DCs, CD141(+) DCs, and MoDCs are capable of cross-presentation; however, they do so via different mechanisms. Moreover, they demonstrate that human CD141(+) DCs, like their murine CD8α(+) DC counterparts, are specialized at cross-presenting cellular Ag, most likely mediated by an enhanced capacity to ingest cellular Ag combined with subtle changes in lysosomal pH during Ag processing and use of the cytosolic pathway.

Elevated YKL40 is associated with advanced prostate cancer (PCa) and positively regulates invasion and migration of PCa cells.

Chitinase 3-like 1 (CHI3L1 or YKL40) is a secreted glycoprotein highly expressed in tumours from patients with advanced stage cancers, including prostate cancer (PCa). The exact function of YKL40 is poorly understood, but it has been shown to play an important role in promoting tumour angiogenesis and metastasis. The therapeutic value and biological function of YKL40 are unknown in PCa. The objective of this study was to examine the expression and function of YKL40 in PCa. Gene expression analysis demonstrated that YKL40 was highly expressed in metastatic PCa cells when compared with less invasive and normal prostate epithelial cell lines. In addition, the expression was primarily limited to androgen receptor-positive cell lines. Evaluation of YKL40 tissue expression in PCa patients showed a progressive increase in patients with aggressive disease when compared with those with less aggressive cancers and normal controls. Treatment of LNCaP and C4-2B cells with androgens increased YKL40 expression, whereas treatment with an anti-androgen agent decreased the gene expression of YKL40 in androgen-sensitive LNCaP cells. Furthermore, knockdown of YKL40 significantly decreased invasion and migration of PCa cells, whereas overexpression rendered them more invasive and migratory, which was commensurate with an enhancement in the anchorage-independent growth of cells. To our knowledge, this study characterises the role of YKL40 for the first time in PCa. Together, these results suggest that YKL40 plays an important role in PCa progression and thus inhibition of YKL40 may be a potential therapeutic strategy for the treatment of PCa.

Human CD141+ (BDCA-3)+ dendritic cells (DCs) represent a unique myeloid DC subset that cross-presents necrotic cell antigens.

The characterization of human dendritic cell (DC) subsets is essential for the design of new vaccines. We report the first detailed functional analysis of the human CD141+ DC subset. CD141+ DCs are found in human lymph nodes, bone marrow, tonsil, and blood, and the latter proved to be the best source of highly purified cells for functional analysis. They are characterized by high expression of toll-like receptor 3, production of IL-12p70 and IFN-beta, and superior capacity to induce T helper 1 cell responses, when compared with the more commonly studied CD1c+ DC subset. Polyinosine-polycytidylic acid (poly I:C)-activated CD141+ DCs have a superior capacity to cross-present soluble protein antigen (Ag) to CD8+ cytotoxic T lymphocytes than poly I:C-activated CD1c+ DCs. Importantly, CD141+ DCs, but not CD1c+ DCs, were endowed with the capacity to cross-present viral Ag after their uptake of necrotic virus-infected cells. These findings establish the CD141+ DC subset as an important functionally distinct human DC subtype with characteristics similar to those of the mouse CD8alpha+ DC subset. The data demonstrate a role for CD141+ DCs in the induction of cytotoxic T lymphocyte responses and suggest that they may be the most relevant targets for vaccination against cancers, viruses, and other pathogens.

Modeling prostate cancer: a perspective on transgenic mouse models.

Despite considerable success in treatment of early stage localized prostate cancer (PC), acute inadequacy of late stage PC treatment and its inherent heterogeneity poses a formidable challenge. Clearly, an improved understanding of PC genesis and progression along with the development of new targeted therapies are warranted. Animal models, especially, transgenic immunocompetent mouse models, have proven to be the best ally in this respect. A series of models have been developed by modulation of expression of genes implicated in cancer-genesis and progression; mainly, modulation of expression of oncogenes, steroid hormone receptors, growth factors and their receptors, cell cycle and apoptosis regulators, and tumor suppressor genes have been used. Such models have contributed significantly to our understanding of the molecular and pathological aspects of PC initiation and progression. In particular, the transgenic mouse models based on multiple genetic alterations can more accurately address the inherent complexity of PC, not only in revealing the mechanisms of tumorigenesis and progression but also for clinically relevant evaluation of new therapies. Further, with advances in conditional knockout technologies, otherwise embryonically lethal gene changes can be incorporated leading to the development of new generation transgenics, thus adding significantly to our existing knowledge base. Different models and their relevance to PC research are discussed.

Broadening of transgenic adenocarcinoma of the mouse prostate (TRAMP) model to represent late stage androgen depletion independent cancer.

BACKGROUND: The transgenic adenocarcinoma of the mouse prostate (TRAMP) model closely mimics PC-progression as it occurs in humans. However, the timing of disease incidence and progression (especially late stage) makes it logistically difficult to conduct experiments synchronously and economically. The development and characterization of androgen depletion independent (ADI) TRAMP sublines are reported. METHODS: Sublines were derived from androgen-sensitive TRAMP-C1 and TRAMP-C2 cell lines by androgen deprivation in vitro and in vivo. Epithelial origin (cytokeratin) and expression of late stage biomarkers (E-cadherin and KAI-1) were evaluated using immunohistochemistry. Androgen receptor (AR) status was assessed through quantitative real time PCR, Western blotting, and immunohistochemistry. Coexpression of AR and E-cadherin was also evaluated. Clonogenicity and invasive potential were measured by soft agar and matrigel invasion assays. Proliferation/survival of sublines in response to androgen was assessed by WST-1 assay. In vivo growth of subcutaneous tumors was assessed in castrated and sham-castrated C57BL/6 mice. RESULTS: The sublines were epithelial and displayed ADI in vitro and in vivo. Compared to the parental lines, these showed (1) significantly faster growth rates in vitro and in vivo independent of androgen depletion, (2) greater tumorigenic, and invasive potential in vitro. All showed substantial downregulation in expression levels of tumor suppressor, E-cadherin, and metastatis suppressor, KAI-1. Interestingly, the percentage of cells expressing AR with downregulated E-cadherin was higher in ADI cells, suggesting a possible interaction between the two pathways. CONCLUSIONS: The TRAMP model now encompasses ADI sublines potentially representing different phenotypes with increased tumorigenicity and invasiveness.