Development of EphA2 siRNA-loaded lipid nanoparticles and combination with a small-molecule histone demethylase inhibitor in prostate cancer cells and tumor spheroids

BACKGROUND

siRNAs hold a great potential for cancer therapy, however, poor stability in body fluids and low cellular uptake limit their use in the clinic. To enhance the bioavailability of siRNAs in tumors, novel, safe, and effective carriers are needed.

RESULTS

Here, we developed cationic solid lipid nanoparticles (cSLNs) to carry siRNAs targeting EphA2 receptor tyrosine kinase (siEphA2), which is overexpressed in many solid tumors including prostate cancer. Using DDAB cationic lipid instead of DOTMA reduced nanoparticle size and enhanced both cellular uptake and gene silencing in prostate cancer cells. DDAB-cSLN showed better cellular uptake efficiency with similar silencing compared to commercial transfection reagent (Dharmafect 2). After verifying the efficacy of siEphA2-loaded nanoparticles, we further evaluated a potential combination with a histone lysine demethylase inhibitor, JIB-04. Silencing EphA2 by siEphA2-loaded DDAB-cSLN did not affect the viability (2D or 3D culture), migration, nor clonogenicity of PC-3 cells alone. However, upon co-administration with JIB-04, there was a decrease in cellular responses. Furthermore, JIB-04 decreased EphA2 expression, and thus, silencing by siEphA2-loaded nanoparticles was further increased with co-treatment.

CONCLUSIONS

We have successfully developed a novel siRNA-loaded lipid nanoparticle for targeting EphA2. Moreover, preliminary results of the effects of JIB-04, alone and in combination with siEphA2, on prostate cancer cells and prostate cancer tumor spheroids were presented for the first time. Our delivery system provides high transfection efficiency and shows great promise for targeting other genes and cancer types in further in vitro and in vivo studies.

Differential CircRNA Expression Signatures May Serve as Potential Novel Biomarkers in Prostate Cancer

Circular RNAs (circRNAs), a recently discovered non-coding RNA, have a number of functions including the regulation of miRNA expression. They have been detected in a number of malignancies including prostate cancer (PCa). The differential expression pattern of circRNAs associated with PCa and androgen receptor (AR) status was investigated in this study. circRNA profiling was performed using a high throughout microarray assay on a panel of prostate cell lines, which consisted of normal, benign, and malignant cells (n = 9). circRNAs were more commonly significantly up-regulated (p < 0.05) than downregulated in malignant cell lines (n = 3,409) vs. benign cell lines (n = 2,949). In a grouped analysis based on AR status, there were 2,127 down-regulated circRNAs in androgen independent cell lines compared to 2,236 in androgen dependent cell lines, thus identifying a potential circRNA signature reflective of androgen dependency. Through a bioinformatics approach, the parental genes associated with the top 10 differentially expressed circRNAs were identified such as hsa_circ_0064644, whose predicted parental gene target is RBMS3, and hsa_circ_0060539, whose predicted gene target is SDC4. Furthermore, we identified three circRNAs associated with the parental gene Caprin1 (hsa_circ_0021652, hsa_circ_0000288, and hsa_circ_0021647). Other studies have shown the importance of Caprin1 in PCa cell survival and drug resistance. Given the modified circRNA expression signatures identified here, these hypothesis generating results suggest that circRNAs may serve as potential putative diagnostic and predictive markers in PCa. However, further validation studies are required to assess the true potential of these markers in the clinical setting.

Diagnostic Strategies for Treatment Selection in Advanced Prostate Cancer

Prostate Cancer (PCa) is a leading cause of morbidity and mortality among men worldwide. For most men with PCa, their disease will follow an indolent course. However, advanced PCa is associated with poor outcomes. There has been an advent of new therapeutic options with proven efficacy for advanced PCa in the last decade which has improved survival outcomes for men with this disease. Despite this, advanced PCa continues to be associated with a high rate of death. There is a lack of strong evidence guiding the timing and sequence of these novel treatment strategies. This paper focuses on a review of the strategies for diagnostic and the current evidence available for treatment selection in advanced PCa.

The Role of Cancer Stem Cells in Drug Resistance in Gastroesophageal Junction Adenocarcinoma

Gastroesophageal junction adenocarcinomas (GEJA) have dramatically increased in incidence in the western world since the mid-20^th century. Their prognosis is poor, and conventional anti-cancer therapies do not significantly improve survival outcomes. These tumours are comprised of a heterogenous population of both cancer stem cells (CSC) and non-CSCs, with the former playing a crucial role in tumorigenesis, metastasis and importantly drug resistance. Due to the ability of CSCs to self-replicate indefinitely, their resistance to anti-cancer therapies poses a significant barrier to effective treatment of GEJA. Ongoing drug development programmes aim to target and eradicate CSCs, however their characterisation and thus identification is difficult. CSC regulation is complex, involving an array of signalling pathways, which are in turn influenced by a number of entities including epithelial mesenchymal transition (EMT), microRNAs (miRNAs), the tumour microenvironment and epigenetic modifications. Identification of CSCs commonly relies on the expression of specific cell surface markers, yet these markers vary between different malignancies and indeed are often co-expressed in non-neoplastic tissues. Development of targeted drug therapies against CSCs thus requires an understanding of disease-specific CSC markers and regulatory mechanisms. This review details the current knowledge regarding CSCs in GEJA, with particular emphasis on their role in drug resistance.

Platelet cloaking of circulating tumour cells in patients with metastatic prostate cancer: Results from ExPeCT, a randomised controlled trial

Background

Circulating tumour cells (CTCs) represent a morphologically distinct subset of cancer cells, which aid the metastatic spread. The ExPeCT trial aimed to examine the effectiveness of a structured exercise programme in modulating levels of CTCs and platelet cloaking in patients with metastatic prostate cancer.

Methods

Participants (n = 61) were randomised into either standard care (control) or exercise arms. Whole blood was collected for all participants at baseline (T0), three months (T3) and six months (T6), and analysed for the presence of CTCs, CTC clusters and platelet cloaking. CTC data was correlated with clinico-pathological information.

Results

Changes in CTC number were observed within group over time, however no significant difference in CTC number was observed between groups over time. Platelet cloaking was identified in 29.5% of participants. A positive correlation between CTC number and white cell count (WCC) was observed (p = 0.0001), in addition to a positive relationship between CTC clusters and PSA levels (p = 0.0393).

Conclusion

The presence of platelet cloaking has been observed in this patient population for the first time, in addition to a significant correlation between CTC number and WCC.

Trial registration

ClincalTrials.gov identifier NCT02453139.

European Cancer Organisation Essential Requirements for Quality Cancer Care (ERQCC): Lung cancer

European Cancer Organisation Essential Requirements for Quality Cancer Care (ERQCC) are written by experts representing all disciplines involved in cancer care in Europe. They give patients, health professionals, managers and policymakers a guide to essential care throughout the patient journey. Lung cancer is the leading cause of cancer mortality and has a wide variation in treatment and outcomes in Europe. It is a major healthcare burden and has complex diagnosis and treatment challenges. Care must only be carried out in lung cancer units or centres that have a core multidisciplinary team (MDT) and an extended team of health professionals detailed here. Such units are far from universal in European countries. To meet European aspirations for comprehensive cancer control, healthcare organisations must consider the requirements in this paper, paying particular attention to multidisciplinarity and patient-centred pathways from diagnosis, to treatment, to survivorship.

ESR/ERS statement paper on lung cancer screening

In Europe, lung cancer ranks third among the most common cancers, remaining the biggest killer. Since the publication of the first European Society of Radiology and European Respiratory Society joint white paper on lung cancer screening (LCS) in 2015, many new findings have been published and discussions have increased considerably. Thus, this updated expert opinion represents a narrative, non-systematic review of the evidence from LCS trials and description of the current practice of LCS as well as aspects that have not received adequate attention until now. Reaching out to the potential participants (persons at high risk), optimal communication and shared decision-making will be key starting points. Furthermore, standards for infrastructure, pathways and quality assurance are pivotal, including promoting tobacco cessation, benefits and harms, overdiagnosis, quality, minimum radiation exposure, definition of management of positive screen results and incidental findings linked to respective actions as well as cost-effectiveness. This requires a multidisciplinary team with experts from pulmonology and radiology as well as thoracic oncologists, thoracic surgeons, pathologists, family doctors, patient representatives and others. The ESR and ERS agree that Europe's health systems need to adapt to allow citizens to benefit from organised pathways, rather than unsupervised initiatives, to allow early diagnosis of lung cancer and reduce the mortality rate. Now is the time to set up and conduct demonstration programmes focusing, among other points, on methodology, standardisation, tobacco cessation, education on healthy lifestyle, cost-effectiveness and a central registry.

ESR/ERS statement paper on lung cancer screening

In Europe, lung cancer ranks third among the most common cancers, remaining the biggest killer. Since the publication of the first European Society of Radiology and European Respiratory Society joint white paper on lung cancer screening (LCS) in 2015, many new findings have been published and discussions have increased considerably. Thus, this updated expert opinion represents a narrative, non-systematic review of the evidence from LCS trials and description of the current practice of LCS as well as aspects that have not received adequate attention until now. Reaching out to the potential participants (persons at high risk), optimal communication and shared decision-making will be key starting points. Furthermore, standards for infrastructure, pathways and quality assurance are pivotal, including promoting tobacco cessation, benefits and harms, overdiagnosis, quality, minimum radiation exposure, definition of management of positive screen results and incidental findings linked to respective actions as well as cost-effectiveness. This requires a multidisciplinary team with experts from pulmonology and radiology as well as thoracic oncologists, thoracic surgeons, pathologists, family doctors, patient representatives and others. The ESR and ERS agree that Europe's health systems need to adapt to allow citizens to benefit from organised pathways, rather than unsupervised initiatives, to allow early diagnosis of lung cancer and reduce the mortality rate. Now is the time to set up and conduct demonstration programmes focusing, among other points, on methodology, standardisation, tobacco cessation, education on healthy lifestyle, cost-effectiveness and a central registry.Key Points• Pulmonologists and radiologists both have key roles in the set up of multidisciplinary LCS teams with experts from many other fields.• Pulmonologists identify people eligible for LCS, reach out to family doctors, share the decision-making process and promote tobacco cessation.• Radiologists ensure appropriate image quality, minimum dose and a standardised reading/reporting algorithm, together with a clear definition of a "positive screen".• Strict algorithms define the exact management of screen-detected nodules and incidental findings.• For LCS to be (cost-)effective, it has to target a population defined by risk prediction models.

A randomized trial of exercise on quality of life in men with metastatic prostate cancer: The ExPeCT Trial

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Background: All patients living with cancer, including those with metastatic cancer, are encouraged to be physically active. This paper examines the feasibility of an aerobic exercise intervention for men with metastatic prostate cancer. Methods: ExPeCT (Exercise, Prostate Cancer and Circulating Tumour Cells), was a multi-centre randomised control trial for men living with metastatic prostate cancer. Participants were randomized to either control or exercise arms. Participants in the exercise arm completed six- months of prescribed aerobic exercise. Quality of life assessments were completed at baseline, at 3 months and at 6 months using a standardised questionnaire derived from the Harvard Health Professionals Follow-up study. Physical activity was measured using a self-administered physical activity questionnaire. Exercise adherence data was collected via Polar heart rate monitors, worn by the patient for every exercise session undertaken. Results: A total of 61 patients were included (69.4±7.3 yr, Body Mass Index 29.2±5.8 kg/m2). The median time since diagnosis was 34 months (IQR 7-54). A total of 35 (55%) of participants had >1 region affected by metastatic disease. A total of 54 (81%) of participants completed the 3 month assessment and 52 (78%) of the participants completed the 6 month assessment. Adherence to the supervised sessions was 83% (329 out of 396 sessions attended). Participants were adherent to both the intensity (82%) and duration (83%) of the prescribed exercise programme during class sessions. No adverse events were reported by participants enrolled in this study. There was no significant difference in physical activity levels, sedentary time or quality of life between either group at baseline, 3 months or 6 months. Systolic blood pressure was significantly lower in the exercise group when compared to the control group at 3 months (p=.008) and 6 months (p=.011). Conclusions: The exercise intervention was tolerated well by a group of patients with a high burden of metastatic prostate cancer however did not lead to change in physical activity levels or quality of life. This trial provides proof of principle evidence for future exercise studies involving this patient group. Clinical trial information: NCT02453139.

Circular RNAs are differentially expressed in prostate cancer and are potentially associated with resistance to enzalutamide

Most forms of castration-resistant prostate cancer (CRPC) are dependent on the androgen receptor (AR) for survival. While, enzalutamide provides a substantial survival benefit, it is not curative and many patients develop resistance to therapy. Although not yet fully understood, resistance can develop through a number of mechanisms, such as AR copy number gain, the generation of splice variants such as AR-V7 and mutations within the ligand binding domain (LBD) of the AR. circular RNAs (circRNAs) are a novel type of non-coding RNA, which can regulate the function of miRNA, and may play a key role in the development of drug resistance. circRNAs are highly resistant to degradation, are detectable in plasma and, therefore may serve a role as clinical biomarkers. In this study, AR-V7 expression was assessed in an isogenic model of enzalutamide resistance. The model consisted of age matched control cells and two sub-line clones displaying varied resistance to enzalutamide. circRNA profiling was performed on the panel using a high throughout microarray assay. Bioinformatic analysis identified a number of differentially expressed circRNAs and predicted five miRNA binding sites for each circRNA. miRNAs were stratified based on known associations with prostate cancer, and targets were validated using qPCR. Overall, circRNAs were more often down regulated in resistant cell lines compared with control (588 vs. 278). Of particular interest was hsa_circ_0004870, which was down-regulated in enzalutamide resistant cells (p ≤ 0.05, vs. sensitive cells), decreased in cells that highly express AR (p ≤ 0.01, vs. AR negative), and decreased in malignant cells (p ≤ 0.01, vs. benign). The associated parental gene was identified as RBM39, a member of the U2AF65 family of proteins. Both genes were down-regulated in resistant cells (p < 0.05, vs. sensitive cells). This is one of the first studies to profile and demonstrate discrete circRNA expression patterns in an enzalutamide resistant cell line model of prostate cancer. Our data suggests that hsa_circ_0004870, through RBM39, may play a critical role in the development of enzalutamide resistance in CRPC.

An updated analysis evaluating skeletal related events (SREs) in CTRIAL-IE 13-21: Phase II trial of radium-223 (R223) in combination with enzalutamide (ENZA) for patients (pts) with metastatic castration-resistant prostate cancer (mCRPC)

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Background: This phase II single arm study, previously reported on the safety and tolerability of the combination of R223 and ENZA in pts with mCRPC. R223 in combination with ENZA was well tolerated with acceptable safety and toxicity profiles. Methods: This study enrolled pts with mCRPC to bone with or without visceral/lymph node involvement progressing on ADT. Pts received 6 cycles of R223 (55 kBq/kg IV Q4W) in combination with ENZA (160mg/day), followed by ENZA alone. Bone health agents were initiated as per treating clinician choice. SREs were defined as: a pathologic fracture, spinal cord compression (SCC), necessity for external beam radiation (EBRT) or surgery to bone. SREs during the combination period and after completion of R223 are reported here. An unplanned retrospective analysis of all scans performed on each patient for any fracture was performed and is included. Results: From July 2015 to July 2017, 45 pts were enrolled. 42 pts (93.3%) received all 6 cycles of combination therapy. 16 pts (35.5%) remain on ENZA alone. In total, 6 pts (13.3%) had SREs. 4 developed pathological fractures (femur = 1, vertebrae = 3) while 3 had EBRT for pain. Of these 6 pts, 2 developed SCC requiring EBRT. The average time from starting R223 to SRE was 615 days. 2/6 pts were not receiving bone protection. One pt who developed a pathological fracture has subsequently died related to progressive disease (time to death = 292 days). In the retrospective analysis, 4 pts (8.8%) developed fractures which were associated with a history of trauma (radius = 1, tibia = 1 ribs = 2). 11 pts (24.4%) developed asymptomatic insufficiency fractures (ankle = 1, femur = 1, sacrum = 2, vertebrae = 4, ribs = 4). The average time to insufficiency fracture was 354 days. No interventions were required. The majority of pts (75.5%) on the study were receiving bone health agents. Conclusions: SREs were in keeping with previously published data. In an unplanned retrospective analysis, there was a higher incidence of asymptomatic insufficiency fractures in this cohort of patients, however no interventions were required. Clinical trial information: NCT02225704.

The effect of a structured exercise intervention on CTCs and platelet cloaking in patients with metastatic prostate cancer

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Background: Physical activity has been described as an effective adjunct for improving quality of life in patients with metastatic prostate cancer (PrCa). Circulating tumor cells (CTCs) are a morphologically distinct set of cancer cells, involved in disease progression. Platelet cloaking, the surrounding and subsequent attachment of platelets to CTCs, has been proposed as effective in aiding extravasation, thus enhancing metastatic spread. The ExPeCT (Exercise, Prostate Cancer and Circulating Tumor Cells) trial aimed to examine the impact of a structured exercise intervention on the mechanisms of metastasis, including CTC cloaking, in patients with metastatic PrCa. Methods: ExPeCT was a multi-center, randomized trial for patients with metastatic PrCa (n=61). Participants were randomized to either control or exercise arms. Participants in the exercise arm (n=29) completed six months of prescribed aerobic exercise. Whole blood was collected for all participants at baseline (T0), three months (T3) and six months (T6), and analyzed for the presence of CTCs, CTC clusters and platelet cloaking. Results: No significant difference in CTC number between the exercise and control arms was observed (p=0.2630), however significant alterations in CTC number were observed within group over time (p<0.001). Platelet cloaking was modelled as a binary response (presence/absence). A trend towards higher levels of platelet cloaking in the control group was observed (p=0.1005). Further, all findings were compared to a range of clinical variables. CTC clusters were positively correlated with PSA levels (p=0.0393) and a positive correlation between CTC number and white blood cell count (p<0.001) was determined. Conclusions: No significant relationship between CTCs and physical activity was observed, however the exercise program was well tolerated by ExPeCT participants. This study has, for the first time, shown platelet cloaking of CTCs in metastatic PrCa, in addition to a significant positive correlation between CTCs and white blood cells. These findings provide critical insight into immune crosstalk and the metastatic cascade in metastatic PrCa. Clinical trial information: NCT02453139.

When RON MET TAM in Mesothelioma: All Druggable for One, and One Drug for All?

Malignant pleural mesothelioma (MPM) is an aggressive inflammatory cancer with a poor survival rate. Treatment options are limited at best and drug resistance is common. Thus, there is an urgent need to identify novel therapeutic targets in this disease in order to improve patient outcomes and survival times. MST1R (RON) is a trans-membrane receptor tyrosine kinase (RTK), which is part of the c-MET proto-oncogene family. The only ligand recognized to bind MST1R (RON) is Macrophage Stimulating 1 (MST1), also known as Macrophage Stimulating Protein (MSP) or Hepatocyte Growth Factor-Like Protein (HGFL). In this study, we demonstrate that the MST1-MST1R (RON) signaling axis is active in MPM. Targeting this pathway with a small molecule inhibitor, LCRF-0004, resulted in decreased proliferation with a concomitant increase in apoptosis. Cell cycle progression was also affected. Recombinant MST1 treatment was unable to overcome the effect of LCRF-0004 in terms of either proliferation or apoptosis. Subsequently, the effect of an additional small molecular inhibitor, BMS-777607 (which targets MST1R (RON), MET, Tyro3, and Axl) also resulted in a decreased proliferative capacity of MPM cells. In a cohort of MPM patient samples, high positivity for total MST1R by IHC was an independent predictor of favorable prognosis. Additionally, elevated expression levels of MST1 also correlated with better survival. This study also determined the efficacy of LCRF-0004 and BMS-777607 in xenograft MPM models. Both LCRF-0004 and BMS-777607 demonstrated significant anti-tumor efficacy in vitro, however BMS-777607 was far superior to LCRF-0004. The in vivo and in vitro data generated by this study indicates that a multi-TKI, targeting the MST1R/MET/TAM signaling pathways, may provide a more effective therapeutic strategy for the treatment of MPM as opposed to targeting MST1R alone.

RNAs as Candidate Diagnostic and Prognostic Markers of Prostate Cancer-From Cell Line Models to Liquid Biopsies

The treatment landscape of prostate cancer has evolved rapidly over the past five years. The explosion in treatment advances has been witnessed in parallel with significant progress in the field of molecular biomarkers. The advent of next-generation sequencing has enabled the molecular profiling of the genomic and transcriptomic architecture of prostate and other cancers. Coupled with this, is a renewed interest in the role of non-coding RNA (ncRNA) in prostate cancer biology. ncRNA consists of several different classes including small non-coding RNA (sncRNA), long non-coding RNA (lncRNA), and circular RNA (circRNA). These families are under active investigation, given their essential roles in cancer initiation, development and progression. This review focuses on the evidence for the role of RNAs in prostate cancer, and their use as diagnostic and prognostic markers, and targets for treatment in this disease.

Abstract A057: Examining the link between obesity, inflammation, and exercise in patients with metastatic prostate cancer—An interim analysis from the ExPeCT trial

Background: Globally, prostate cancer (PrCa) is the fourth most common cancer type. Obesity and inflammation have been shown to play significant roles in PrCa disease progression. Obesity and a high body mass index (BMI) are associated with increased PrCa-specific mortality in patients with advanced disease. Furthermore, proinflammatory cytokines can aid metastatic potential and promote angiogenesis. The ExPeCT (Exercise, Prostate Cancer and Circulating Tumor Cells) trial seeks to examine the effectiveness of a structured exercise program in modulating inflammatory mediators and obesity in patients with metastatic PrCa.

Methods: ExPeCT (CTRIALIE 15-21 (ClincalTrials.gov identifier NCT02453139)) is a multicenter, randomized trial for patients with metastatic PrCa (n=67). Participants were randomized to either control or exercise arms. Participants in the exercise arm completed six months of prescribed aerobic exercise, which was monitored using percentage heart-rate reserve. Serum samples were collected for all participants at baseline (T0), three months (T3), and six months (T6), and assayed for 16 interlinked adipokines and cytokines using the Meso Scale Discovery platform. An interim statistical analysis was performed (n=26) comparing median change in serum analyte levels between control (n=13) and exercise (n=13) arms using non-parametric Wilcoxon rank-sum tests.

Results: Among 26 patients included in our interim analysis, mean age at baseline was 71 years, median BMI was 29.1 kg/m2, and median waist circumference (WC) was 107 cm, with no significant differences between arms (all p&gt;0.3). Between T0 and T6, WC decreased by a median of 3.8 cm in the exercise group and 2.6 cm in the control group (p=0.412), with a similar trend for BMI. Interim serum cytokine analysis showed a 3-fold increase in IL-10 levels in the exercise arm at T3 when compared to the control arm (p=0.036). No significant change in IL-10 levels was recorded at T6 between arms (p=0.776). Similarly, CXCL8 (IL-8) levels were increased by 1.8-fold at T3 in the exercise arm in comparison to the control arm (p=0.017), with no significant change reported at T6 (p=0.191). While changes were evident in serum TNFα, IL-6, VEGF, IL-17a, MMP9 and CCL5 (RANTES) levels, these did not reach significance. Differences in levels of adipokines leptin and resistin were also reported. A 1.5-fold increase in resistin expression was observed in the exercise arm at T6; however, it was not significant (p=0.293). A 2-fold decrease in leptin in the control arm relative to the exercise arm at T6 was also detected (p=0.676). Analysis of adiponectin, MMP2, and CCL2 is ongoing.

Conclusion: Our interim analysis of ExPeCT trial participants demonstrated a significant increase in serum CXCL8 and IL-10 levels after three months of a supervised exercise intervention. These preliminary data suggest that a structured exercise program has the potential to modify inflammatory status in patients with metastatic PrCa.

Citation Format: Lauren Brady, Grainne Sheill, Anne-Marie Baird, Emma H. Allott, Tatjana Vlajnic, John Greene, Orla Casey, Brian Hayes, Emer Guinan, Juliette Hussey, Fidelma Cahill, Mieke Van Hemelrijck, Nicola Peat, Sarah Rudman, Moya Cunningham, Liam Grogan, Thomas Lynch, Rustom P. Manecksha, John McCaffrey, Orla Sheils, Dearbhaile M. O’Donnell, John O’Leary, Ray McDermott, Stephen P. Finn. Examining the link between obesity, inflammation, and exercise in patients with metastatic prostate cancer—An interim analysis from the ExPeCT trial [abstract]. In: Proceedings of the AACR Special Conference: Prostate Cancer: Advances in Basic, Translational, and Clinical Research; 2017 Dec 2-5; Orlando, Florida. Philadelphia (PA): AACR; Cancer Res 2018;78(16 Suppl):Abstract nr A057.

Abstract A059: Lifestyle and health-related quality of life in men with metastatic prostate cancer

Background: Patients with metastatic prostate cancer live with a considerable disease burden that may have a profound impact on physical activity and quality of life. This patient group may survive for many years after disease onset; however, there is little evidence on their habitual levels of physical activity. The aim of this study was to investigate physical activity levels and associated health-related quality of life in prostate cancer patients with bone metastases.

Methods: ExPeCT (Exercise, Prostate Cancer and Circulating Tumour Cells: CTRIAL-IE 15-21) (ClincalTrials.gov identifier NCT02453139) is an ongoing multicenter trial examining the effect of a 6-month structured exercise intervention for patients with metastatic prostate cancer. Participants complete questionnaires examining self-reported health-related quality of life (FACT-P), sleep (Pittsburgh Sleep Index), depression (PHQ-9), and physical activity (Harvard Health Professionals Study Questionnaire) at baseline, three, and six months. Analysis of 3- and 6-month data is ongoing.

Result: An interim analysis of the baseline outcome measures of 64 patients with bone metastases was completed (mean age 69.4 (SD 7.35) years and mean BMI 29.2 (SD 5.8) kg/m2). Median time since diagnosis was 34 months (IQR 7-54) and 55% (n=35) of participants had &gt;1 region affected by metastatic disease. Preliminary data demonstrated that 38% (n=24) of participants did not meet the current aerobic exercise guidelines for cancer survivors. In total, 20% (n=13) of participants reported engaging in vigorous activity and 16% (n=11) reported completing resistance exercise. There was no correlation found between physical activity levels and quality of life (r=0.01), sleep (r=0.02), or depression (r=-0.15) scores. The majority of participants (61% (n=41)) had sleep scores of &gt;7, indicative of poor sleep quality. Sleep scores correlated negatively with global quality of life (r =-0.55, p&lt;0.05). Patients scored lowest in the “functional” and “additional prostate cancer-related concerns” domains of quality of life.

Discussion: Findings highlight the association between reduced quality of life and poor sleep quality among men with metastatic prostate cancer. In addition, data suggest a high prevalence of suboptimal physical activity levels in this population. Patients with metastatic disease may benefit from lifestyle interventions that aim to increase physical activity levels.

Citation Format: Gráinne Sheill, Lauren Brady, Emer Guinan, Juliette Hussey, David Hevey, Tatjana Vlajnic, Orla Casey, Anne-Marie Baird, Fidelma Cahill, Mieke Van Hemelrijck, Nicola Peat, Sarah Rudman, Thomas Lynch, Rustom P. Manecksha, Brian Hayes, Moya Cunningham, Liam Grogan, John McCaffrey, Dearbhaile M. O’Donnell, Ray McDermott, John O Leary, Stephen P. Finn. Lifestyle and health-related quality of life in men with metastatic prostate cancer [abstract]. In: Proceedings of the AACR Special Conference: Prostate Cancer: Advances in Basic, Translational, and Clinical Research; 2017 Dec 2-5; Orlando, Florida. Philadelphia (PA): AACR; Cancer Res 2018;78(16 Suppl):Abstract nr A059.

Carcinogenesis in prostate cancer: The role of long non-coding RNAs

LncRNAs appear to play a considerable role in tumourigenesis through regulating key processes in cancer cells such as proliferative signalling, replicative immortality, invasion and metastasis, evasion of growth suppressors, induction of angiogenesis and resistance to apoptosis. LncRNAs have been reported to play a role in prostate cancer, particularly in regulating the androgen receptor signalling pathway. In this review article, we summarise the role of 34 lncRNAs in prostate cancer with a particular focus on their role in the androgen receptor signalling pathway and the epithelial to mesenchymal transition pathway.

Circular RNAs: Biogenesis, Function and Role in Human Diseases

Circular RNAs (circRNAs) are currently classed as non-coding RNA (ncRNA) that, unlike linear RNAs, form covalently closed continuous loops and act as gene regulators in mammals. They were originally thought to represent errors in splicing and considered to be of low abundance, however, there is now an increased appreciation of their important function in gene regulation. circRNAs are differentially generated by backsplicing of exons or from lariat introns. Unlike linear RNA, the 3' and 5' ends normally present in an RNA molecule have been joined together by covalent bonds leading to circularization. Interestingly, they have been found to be abundant, evolutionally conserved and relatively stable in the cytoplasm. These features confer numerous potential functions to circRNAs, such as acting as miRNA sponges, or binding to RNA-associated proteins to form RNA-protein complexes that regulate gene transcription. It has been proposed that circRNA regulate gene expression at the transcriptional or post-transcriptional level by interacting with miRNAs and that circRNAs may have a role in regulating miRNA function in cancer initiation and progression. circRNAs appear to be more often downregulated in tumor tissue compared to normal tissue and this may be due to (i) errors in the back-splice machinery in malignant tissues, (ii) degradation of circRNAs by deregulated miRNAs in tumor tissue, or (iii) increasing cell proliferation leading to a reduction of circRNAs. circRNAs have been identified in exosomes and more recently, chromosomal translocations in cancer have been shown to generate aberrant fusion-circRNAs associated with resistance to drug treatments. In addition, though originally thought to be non-coding, there is now increasing evidence to suggest that select circRNAs can be translated into functional proteins. Although much remains to be elucidated about circRNA biology and mechanisms of gene regulation, these ncRNAs are quickly emerging as potential disease biomarkers and therapeutic targets in cancer.

Activation and cleavage of SASH1 by caspase-3 mediates an apoptotic response

Apoptosis is a highly regulated cellular process that functions to remove undesired cells from multicellular organisms. This pathway is often disrupted in cancer, providing tumours with a mechanism to avoid cell death and promote growth and survival. The putative tumour suppressor, SASH1 (SAM and SH3 domain containing protein 1), has been previously implicated in the regulation of apoptosis; however, the molecular role of SASH1 in this process is still unclear. In this study, we demonstrate that SASH1 is cleaved by caspase-3 following UVC-induced apoptosis. Proteolysis of SASH1 enables the C-terminal fragment to translocate from the cytoplasm to the nucleus where it associates with chromatin. The overexpression of wild-type SASH1 or a cleaved form of SASH1 representing amino acids 231-1247 leads to an increase in apoptosis. Conversely, mutation of the SASH1 cleavage site inhibits nuclear translocation and prevents the initiation of apoptosis. SASH1 cleavage is also required for the efficient translocation of the transcription factor nuclear factor-κB (NF-κB) to the nucleus. The use of the NF-κB inhibitor DHMEQ demonstrated that the effect of SASH1 on apoptosis was dependent on NF-κB, indicating a codependence between SASH1 and NF-κB for this process.

Drug Discovery Approaches Utilizing Three-Dimensional Cell Culture

Historically, two-dimensional (2D) cell culture has been the preferred method of producing disease models in vitro. Recently, there has been a move away from 2D culture in favor of generating three-dimensional (3D) multicellular structures, which are thought to be more representative of the in vivo environment. This transition has brought with it an influx of technologies capable of producing these structures in various ways. However, it is becoming evident that many of these technologies do not perform well in automated in vitro drug discovery units. We believe that this is a result of their incompatibility with high-throughput screening (HTS). In this study, we review a number of technologies, which are currently available for producing in vitro 3D disease models. We assess their amenability with high-content screening and HTS and highlight our own work in attempting to address many of the practical problems that are hampering the successful deployment of 3D cell systems in mainstream research.