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Abstract Background Argonaute-2 (Ago2) is an essential component of microRNA biogenesis implicated in tumourigenesis. However Ago2 expression and localisation in breast cancer remains undetermined. The aim was to define Ago2 expression (mRNA and protein) and localisation in breast cancer, and investigate associations with clinicopathological details. Methods Ago2 protein was stained in breast cancer cell lines and tissue microarrays (TMAs), with intensity and localization assessed. Staining intensity was correlated with clinicopathological details. Using independent databases, Ago2 mRNA expression and gene alterations in breast cancer were investigated. Results In the breast cancer TMAs, 4 distinct staining intensities were observed (Negative, Weak, Moderate, Strong), with 64.2% of samples stained weak or negatively for Ago2 protein. An association was found between strong Ago2 staining and, the Her2 positive or basal subtypes, and between Ago2 intensity and receptor status (Estrogen or Progesterone). In tumours Ago2 mRNA expression correlated with reduced relapse free survival. Conversely, Ago2 mRNA was expressed significantly lower in SK-BR-3 (HER2 positive) and BT-20 (Basal/Triple negative) cell lines. Interestingly, high levels of Ago2 gene amplification (10–27%) were observed in breast cancer across multiple patient datasets. Importantly, knowledge of Ago2 expression improves predictions of breast cancer subtype by 20%, ER status by 15.7% and PR status by 17.5%. Conclusions Quantification of Ago2 improves the stratification of breast cancer and suggests a differential role for Ago2 in breast cancer subtypes, based on levels and cellular localisation. Further investigation of the mechanisms affecting Ago2 dysregulation will reveal insights into the molecular differences underpinning breast cancer subtypes.

Background: While long-term outcomes have improved for patients with breast cancer, 20% to 30% will still develop recurrence, and identifying these patients remains a challenge. MicroRNAs (miRNAs) are small, noncoding molecules that modulate genetic expression and affect oncogenesis., Study Design: This prospective, multicenter trial (ICORG10/11-NCT01722851) recruited patients undergoing neoadjuvant chemotherapy across 8 Irish centers. Predetermined miRNAs were quantified from patient whole blood using quantitative reverse transcriptase polymerase chain reaction. Venous sampling was performed at diagnosis (timepoint 1) and midway during neoadjuvant chemotherapy (timepoint 2 [T2]). miRNA expression profiles were correlated with recurrence-free survival (RFS), disease-free survival (DFS), and overall survival. Data analysis was performed using R v3.2.3., Results: A total of 124 patients were recruited with a median age of 55.0 years. The median follow-up was 103.1 months. Increased miR-145 expression at T2 was associated with improved RFS (hazard ratio 0.00; 95% confidence interval [CI] 0.00 to 0.99; p = 0.050). Using survival regression tree analysis, a relative cutoff of increased miR-145 expression greater than 0.222 was associated with improved RFS (p = 0.041). Increased miR-145 expression at T2 trended towards significance in predicting improved DFS (hazard ratio 0.00; 95% CI 0.00 to 1.42; p = 0.067). Using survival regression tree analysis, a relative cutoff of increased miR-145 expression greater than 0.222 was associated with improved DFS (p = 0.012). No miRNAs correlated with overall survival., Conclusions: ICORG10/11 is the first Irish multicenter, translational research trial evaluating circulatory miRNAs as biomarkers predictive of long-term survival and correlated increased miR-145 expression with enhanced outcomes in early-stage breast cancer. Validation of these findings is required in the next generation of translational research trials., (Copyright © 2022 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American College of Surgeons.)

Objective: To evaluate whether circulating micro ribonucleic acids (miRNAs) predict response to neoadjuvant chemotherapy (NAC) and inform decision-making in breast cancer patients., Introduction: Deciphering response to NAC remains a challenge. Those unlikely to respond may benefit from NAC de-escalation before completion, while "responders" should complete treatment. Establishing biomarkers which identify response to NAC is imperative to personalize treatment strategies. miRNAs are small noncoding RNA molecules which modulate genetic expression. miRNAs are believed to inform response to NAC., Methods: This prospective, multicenter trial (NCT01722851) recruited 120 patients treated with NAC across 8 Irish treatment sites. Predetermined miRNAs were quantified from patient whole bloods using relative quantification polymerase chain reactiond. Venous sampling was performed at diagnosis and midway during NAC. Trends in miRNA expression between timepoints were correlated with treatment response. Data analysis was performed using R 3.2.3., Results: A total of 120 patients were included (median age: 55 years). Overall, 49.2% had luminal breast cancers (59/120), 17.5% luminal B (L/HER2) (21/120), 12.5% human epidermal growth factor receptor-2 positive (HER2+) (15/120), and 20.8% triple negative disease (25/120). In total, 46.7% of patients responded to NAC (56/125) and 26.7% achieved a pathological complete response (pCR) (32/120). For patients with L/HER2, increased Let-7a predicted response to NAC ( P =0.049), while decreased miR-145 predicted response to NAC in HER2+ ( P =0.033). For patients with luminal breast cancers, reduced Let-7a predicted achieving a pCR ( P =0.037) and reduced miR-145 predicted achieving a pCR to NAC in HER2+ ( P =0.027)., Conclusions: This study illustrates the potential value of circulatory miRNA measurement in predicting response to NAC. Further interrogation of these findings may see miRNAs personalize therapeutic decision-making for patients undergoing NAC for early breast cancer., Competing Interests: The authors report no conflicts of interest., (Copyright © 2022 The Author(s). Published by Wolters Kluwer Health, Inc.)

Exploratory analysis of cancer consortia data curated by the cBioPortal repository typically requires advanced programming skills and expertise to identify novel genomic prognostic markers that have the potential for both diagnostic and therapeutic exploitation. We developed GNOSIS (GeNomics explOrer using StatistIcal and Survival analysis in R), an R Shiny App incorporating a range of R packages enabling users to efficiently explore and visualise such clinical and genomic data. GNOSIS provides an intuitive graphical user interface and multiple tab panels supporting a range of functionalities, including data upload and initial exploration, data recoding and subsetting, data visualisations, statistical analysis, mutation analysis and, in particular, survival analysis to identify prognostic markers. GNOSIS also facilitates reproducible research by providing downloadable input logs and R scripts from each session, and so offers an excellent means of supporting clinician-researchers in developing their statistical computing skills., Competing Interests: No competing interests were disclosed., (Copyright: © 2022 King L et al.)

Background: Approximately one-third of colorectal cancer (CRC) patients will suffer recurrence. MiRNAs are small non-coding RNAs that play important roles in gene expression. We aimed to correlate miRNA expression with aggressive clinicopathological characteristics and survival outcomes in CRC. Methods: Tumour samples were extracted from 74 CRC patients. MiRNAs were quantified using real-time reverse transcriptase polymerase chain reaction. Descriptive statistics and Cox regression analyses were performed to correlate miRNA targets with clinicopathological and outcome data. Results: Aberrant miR-21 and miR-135b expression correlate with increased nodal stage (p = 0.039, p = 0.022). Using univariable Cox regression analyses, reduced miR-135b (β-coefficient −1.126, hazard ratio 0.324, standard error (SE) 0.4698, p = 0.017) and increased miR-195 (β-coefficient 1.442, hazard ratio 4.229, SE 0.446, p = 0.001) predicted time to disease recurrence. Survival regression trees analysis illustrated a relative cut-off of ≤0.488 for miR-195 and a relative cut-off of >−0.218 for miR-135b; both were associated with improved disease recurrence (p < 0.001, p = 0.015). Using multivariable analysis with all targets as predictors, miR-195 (β-coefficient 3.187, SE 1.419, p = 0.025) was the sole significant independent predictor of recurrence. Conclusion: MiR-195 has strong value in predicting time to recurrence in CRC patients. Additionally, miR-21 and miR-135b predict the degree nodal burden. Future studies may include these findings to personalize therapeutic and surgical decision making.

Breast cancer is the leading cause of cancer related death among women. Breast cancers are generally diagnosed and treated based on clinical and histopathological features, along with subtype classification determined by the Prosigna Breast Cancer Prognostic Gene Signature Assay (also known as PAM50). Currently the copy number alteration (CNA) landscape of the tumour is not considered. We set out to examine the role of genomic instability (GI) in breast cancer survival since CNAs reflect GI and correlate with survival in other cancers. We focused on the 70% of breast cancers classified as luminal and carried out a comprehensive survival and association analysis using Molecular Taxonomy of Breast Cancer International Consortium (METABRIC) data to determine whether CNA Score Quartiles derived from absolute CNA counts are associated with survival. Analysis revealed that patients diagnosed with luminal A breast cancer have a CNA landscape associated with disease specific survival, suggesting that CNA Score can provide a statistically robust prognostic factor. Furthermore, stratification of patients into subtypes based on gene expression has shown that luminal A and B cases overlap, and it is in this region we largely observe luminal A cases with reduced survival outlook. Therefore, luminal A breast cancer patients with quantitatively elevated CNA counts may benefit from more aggressive therapy. This demonstrates how individual genomic landscapes can facilitate personalisation of therapeutic interventions to optimise survival outcomes., Competing Interests: The authors have declared that no competing interests exist.

In Europe most environmental based water quality research has focused on both nutrient and microbial contamination which can arise from agricultural processes and inadequate wastewater treatment. Recent work in Ireland has linked the presence of arsenic in groundwater at elevated concentrations at national and subnational scales with bedrock lithology serving as a strong predictor variable. Groundwater data was collected as part of an environmental impact assessment for a road construction project and this resulting groundwater geochemistry dataset was used in this present study to assess the geochemical controls of arsenic in natural waters in addition to biological and nutrient contamination. Physiochemical parameters, trace elements, nutrients, organics, and microbiological parameters were collected for every quarter for four years (2004-2008) in 67 wells. Due to differing sampling procedures and limitations in the data, only one quarter (November 2005) was used to understand groundwater geochemistry in greater detail. Multivariate statistical techniques were used to overcome the presence of non-detect data. This is an important consideration as while methods exist for chemical data, methods incorporating biological data are limited. Elevated levels of nitrate in groundwater may arise from the runoff of septic tanks and/or agricultural practices in the area. Both pesticides and polycyclic aromatic hydrocarbons were not detected in any wells signifying no anthropogenic contamination inputs. However, fuel products such as methyl tert-butyl ether were detected and potentially illustrate point source contamination, these were detected in only one well. Geochemical data indicate that elevated arsenic concentrations are present within alkali-oxic groundwaters through the desorption from Fe and Mn oxyhydroxides, i.e. alkali desorption. This study examines of the geochemistry of arsenic in groundwater in Ireland at a local scale. In addition, the multivariate methods used in this study were able to fully integrate both chemical and biological censored data, which may be applied in other regions with similar data., (Copyright © 2020 The Author(s). Published by Elsevier B.V. All rights reserved.)

Neoadjuvant chemotherapy (NACT) is used in locally advanced breast cancer to reduce tumour burden prior to surgical resection. However, only a subset of NACT treated patients will respond to treatment or achieve a pathologic complete response (pCR). This multicenter, prospective study (CTRIAL-IE (ICORG) 10-11 study) evaluated circulating microRNA as novel non-invasive prognostic biomarkers of NACT response in breast cancer. Selected circulating microRNAs (Let-7a, miR-21, miR-145, miR-155, miR-195) were quantified from patients undergoing standard of care NACT treatment ( n = 114) from whole blood at collected at diagnosis, and the association with NACT response and clinicopathological features evaluated. NACT responders had significantly lower levels of miR-21 ( p = 0.036) and miR-195 ( p = 0.017), compared to non-responders. Evaluating all breast cancer cases miR-21 was found to be an independent predictor of response (OR 0.538, 95% CI 0.308-0.943, p < 0.05). Luminal cancer NACT responders were found to have significantly decreased levels of miR-145 ( p = 0.033) and miR-21 ( p = 0.048), compared to non-responders. This study demonstrates the prognostic ability of miR-21, miR-195 and miR-145 as circulating biomarkers stratifying breast cancer patients by NACT response, identifying patients that will derive the maximum benefit from chemotherapy.

MicroRNAs, as small non-coding regulatory RNAs, play crucial roles in various aspects of breast cancer biology. They have prognostic and diagnostic value, which makes them very interesting molecules to investigate. Reverse transcriptase quantitative polymerase chain reaction (RT-qPCR) is the gold standard method to analyse miRNA expression in breast cancer patients. This study investigated two RT-qPCR methods (absolute and relative) to determine the expression of ten miRNAs in whole blood samples obtained from luminal A breast cancer patients compared to healthy controls. Whole blood samples were collected from 38 luminal A breast cancer patients and 20 healthy controls in Paxgene blood RNA tubes. Total RNA was extracted and analysed by relative and absolute RT-qPCR. For relative RT-qPCR, miR-16 was used as an endogenous control. For absolute RT-qPCR, standard curves were generated using synthetic miRNA oligonucleotides to determine the absolute copy number of each miRNA. Of the ten miRNAs that were analysed, the absolute RT-qPCR method identified six miRNAs (miR-16, miR-145, miR-155, miR-451a, miR-21 and miR-486) that were upregulated and one miRNA (miR-195) that was downregulated. ROC curve and AUC analysis of the data found that the combination of three miRNAs (miR-145, miR-195 and miR-486) had the best diagnostic value for luminal A breast cancer with an AUC of 0.875, with 76% sensitivity and 81% specificity. On the other hand, the relative RT-qPCR method identified two miRNAs (miR-155 and miR-486) that were upregulated and miR-195, which was downregulated. Using this approach, the combination of three miRNAs (miR-155, miR-195 and miR-486) was showed to have an AUC of 0.657 with 65% sensitivity and 69% specificity. We conclude that miR-16 is not a suitable normalizer for the relative expression profiling of miRNAs in luminal A breast cancer patients. Compared to relative quantification, absolute quantification assay is a better method to determine the expression level of circulating miRNAs in Luminal A breast cancer.

Extracellular vesicles (EVs) shuttle microRNA (miRNA) throughout the circulation and are believed to represent a fingerprint of the releasing cell. We isolated and characterized serum EVs of breast tumour-bearing animals, breast cancer (BC) patients, and healthy controls. EVs were characterized using transmission electron microscopy (TEM), protein quantification, western blotting, and nanoparticle tracking analysis (NTA). Absolute quantitative (AQ)-PCR was employed to analyse EV-miR-451a expression. Isolated EVs had the appropriate morphology and size. Patient sera contained significantly more EVs than did healthy controls. In tumour-bearing animals, a correlation between serum EV number and tumour burden was observed. There was no significant relationship between EV protein yield and EV quantity determined by NTA, highlighting the requirement for direct quantification. Using AQ-PCR to relate miRNA copy number to EV yield, a significant increase in miRNA-451a copies/EV was detected in BC patient sera, suggesting potential as a novel biomarker of breast cancer., Competing Interests: The authors declare no conflict of interest.

Background: Argonaute-2 (Ago2) is an essential component of microRNA biogenesis implicated in tumourigenesis. However Ago2 expression and localisation in breast cancer remains undetermined. The aim was to define Ago2 expression (mRNA and protein) and localisation in breast cancer, and investigate associations with clinicopathological details., Methods: Ago2 protein was stained in breast cancer cell lines and tissue microarrays (TMAs), with intensity and localization assessed. Staining intensity was correlated with clinicopathological details. Using independent databases, Ago2 mRNA expression and gene alterations in breast cancer were investigated., Results: In the breast cancer TMAs, 4 distinct staining intensities were observed (Negative, Weak, Moderate, Strong), with 64.2% of samples stained weak or negatively for Ago2 protein. An association was found between strong Ago2 staining and, the Her2 positive or basal subtypes, and between Ago2 intensity and receptor status (Estrogen or Progesterone). In tumours Ago2 mRNA expression correlated with reduced relapse free survival. Conversely, Ago2 mRNA was expressed significantly lower in SK-BR-3 (HER2 positive) and BT-20 (Basal/Triple negative) cell lines. Interestingly, high levels of Ago2 gene amplification (10-27%) were observed in breast cancer across multiple patient datasets. Importantly, knowledge of Ago2 expression improves predictions of breast cancer subtype by 20%, ER status by 15.7% and PR status by 17.5%., Conclusions: Quantification of Ago2 improves the stratification of breast cancer and suggests a differential role for Ago2 in breast cancer subtypes, based on levels and cellular localisation. Further investigation of the mechanisms affecting Ago2 dysregulation will reveal insights into the molecular differences underpinning breast cancer subtypes.

Breast cancer is stratified into four distinct clinical subtypes, using three key biomarkers (Her2/Neu gene status, Estrogen and Progesterone receptor status). However, each subtype is a heterogeneous group, displaying significant variation in survival rates and treatment response. New biomarkers are required to provide more precise stratification of breast cancer cohorts to inform personalised treatment options/predict outcomes. Tip60 is a member of the MYST sub-family of histone acetyltransferases (HATs), and is directly involved in genome maintenance, gene regulation and DNA damage response/repair pathways (key chemotherapeutic influencing mechanisms). We aimed to determine if quantifying Tip60 staining patterns improved breast cancer stratification. We defined Tip60 protein in vivo, quantifying location (cytoplasmic, nuclear), percent of cells and staining intensity in a breast cancer tissue microarray (n = 337). A significant association of specific Tip60 staining patterns with breast cancer subtype, ER or PR status and Tumour grade was found. Importantly, low Tip60 mRNA expression correlated with poor overall survival and relapse free survival. We found Tip60 is a biomarker able to stratify breast cancer patients, and low Tip60 expression is a significant risk factor indicating a higher chance of disease reoccurrence. This work highlights Tip60 regulation as a key factor influencing the development of breast cancer.

Introduction: Hormone receptor status has major implications for treatment and survival of breast cancer. Yet the impact of hormone receptor status on outcome after Trastuzumab has received little attention. The objective here was to explore any differential effects of Trastuzumab treatment (Trast +ve) on Luminal B HER2 or HER2+(ER-) breast cancer subtypes., Methods: A cohort of 469 HER2 receptor-positive breast cancers was categorised by molecular subtype and Trastuzumab treatment. Effects of Trastuzumab treatment on survival, locoregional recurrence and distant metastasis were investigated by subtype, using univariate and multivariate analysis., Results: Trast +ve Luminal B HER2 patients had significant improvements in 5-year DFS (p < 0.001) and OS (p < 0.001), while Trast +ve HER2+(ER-) patients had significant improvements in 5-year DFS (p = 0.012) alone. Only Trast +ve Luminal B HER2 cancers displayed a significant reduction in LRR rates (p < 0.001). A significant reduction in distant metastasis rates was seen in Trast +ve Luminal B HER2 (p < 0.001) and HER2+(ER-) (p = 0.009) cancers. Interestingly, bone metastasis rates in Trast +ve Luminal B HER2 cancers demonstrated the greatest reduction (36.2-6.7%). Multivariate analysis of Trast +ve patients found no difference in distant metastasis rates (p = 0.96) between subtypes. Significantly, lower LRR rates were seen in Trast +ve Luminal B HER2 cancers, compared to Trast +ve HER2+(ER-) (p = 0.018)., Conclusion: An enhanced response to Trastuzumab was seen in Luminal B HER2 cancers. We highlight how Trastuzumab treatment changed the natural history of the HER2 receptor-positive breast cancer, demonstrating improved efficacy in changing the outcome of hormone receptor-positive patients.

Background: Cells release extracellular membrane vesicles including microvesicles known as exosomes. Exosomes contain microRNAs (miRNAs) however the full range within colorectal cancer cell secreted exosomes is unknown., Objective: To identify the full range of exosome encapsulated miRNAs secreted from 2 colorectal cancer cell lines and to investigate engineering of exosomes over-expressing miRNAs., Methods: Exosomes were isolated from HCT-116 and HT-29 cell lines. RNA was extracted from exosomes and microRNA array performed. Cells were engineered to express miR-379 (HCT-116-379) or a non-targeting control (HCT-116-NTC) and functional effects were determined. Exosomes secreted by engineered cells were transferred to recipient cells and the impact examined., Results: Microvesicles 40-100 nm in size secreted by cell lines were visualised and confirmed to express exosomal protein CD63. HT-29 exosomes contained 409 miRNAs, HCT-116 exosomes contained 393, and 338 were common to exosomes from both cell lines. Selected targets were validated. HCT-116-379 cells showed decreased proliferation (12-15% decrease, p < 0.001) and decreased migration (32-86% decrease, p < 0.001) compared to controls. HCT-116-379 exosomes were enriched for miR-379. Confocal microscopy visualised transfer of HCT-116-379 exosomes to recipient cells., Conclusions: Colorectal cancer cells secrete a large number of miRNAs within exosomes. miR-379 decreases cell proliferation and migration, and miR-379 enriched exosomes can be engineered.