The genomic trajectory of ovarian high-grade serous carcinoma can be observed in STIC lesions.

Ovarian high-grade serous carcinoma (HGSC) originates in the fallopian tube, with secretory cells carrying a TP53 mutation, known as p53 signatures, identified as potential precursors. p53 signatures evolve into serous tubal intraepithelial carcinoma (STIC) lesions, which in turn progress into invasive HGSC, which readily spreads to the ovary and disseminates around the peritoneal cavity. We recently investigated the genomic landscape of early- and late-stage HGSC and found higher ploidy in late-stage (median 3.1) than early-stage (median 2.0) samples. Here, to explore whether the high ploidy and possible whole-genome duplication (WGD) observed in late-stage disease were determined early in the evolution of HGSC, we analysed archival formalin-fixed paraffin-embedded (FFPE) samples from five HGSC patients. p53 signatures and STIC lesions were laser-capture microdissected and sequenced using shallow whole-genome sequencing (sWGS), while invasive ovarian/fallopian tube and metastatic carcinoma samples underwent macrodissection and were profiled using both sWGS and targeted next-generation sequencing. Results showed highly similar patterns of global copy number change between STIC lesions and invasive carcinoma samples within each patient. Ploidy changes were evident in STIC lesions, but not p53 signatures, and there was a strong correlation between ploidy in STIC lesions and invasive ovarian/fallopian tube and metastatic samples in each patient. The reconstruction of sample phylogeny for each patient from relative copy number indicated that high ploidy, when present, occurred early in the evolution of HGSC, which was further validated by copy number signatures in ovarian and metastatic tumours. These findings suggest that aberrant ploidy, suggestive of WGD, arises early in HGSC and is detected in STIC lesions, implying that the trajectory of HGSC may be determined at the earliest stages of tumour development. © 2024 The Author(s). The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Diversity of thought: public perceptions of genetic testing across ethnic groups in the UK.

Genetic testing is becoming rapidly more accessible to the general populous either through or outside healthcare systems. Few large-scale studies have been carried out to gauge public opinion in this growing area. Here, we undertook the largest cross-sectional study on genetic testing in the UK. The primary purpose of this study is to identify the differences in attitudes toward genetic testing across ethnic groups. A cohort of 6500 individuals from a diverse population completed a 72-item survey in a cross-sectional study. Responses between ethnic minority and white individuals in the UK were compared using a wilcoxon rank-sum and chi-square tests. The white cohort was approximately twice as likely to have taken a genetic test and 13% more had heard about genetic testing before the survey. The ethnic minority cohort appeared more apprehensive about the impact of genetic testing on employability. This study highlights that in the UK, significant differences in opinions regarding genetic testing exist between white individuals and ethnic minority individuals. There is an urgent need to develop more inclusive strategies to equally inform individuals from all backgrounds to avoid disparities in the utilisation of genetic testing.

Integrative Oncology Approaches to Supporting Immune Checkpoint Inhibitor Treatment of Solid Tumours.

PURPOSE OF REVIEW: The goal of this review was to examine the role and practical applications of integrative oncology strategies in supporting immune checkpoint inhibitor (ICI) treatment of adult solid tumours. RECENT FINDINGS: Beyond tumour-intrinsic factors, several patient-associated factors affect ICI response, including germline genetics, systemic inflammation, the gut microbiota, and diet. Current promising supportive interventions include a Mediterranean-style diet with over 20 g of fibre, regular exercise, use of live biotherapeutics, minimisation of PPI and antibiotic use, and ensuring vitamin D repletion, with many other integrative oncology approaches under study. Caution around medical cannabis use in patients on ICIs is advised due to previously documented adverse impact on overall survival, while VAE (Viscum album extract) therapy studies have not highlighted any safety concerns so far. With expanding ICI use, it is important to investigate and apply low-cost integrative oncology strategies to support better treatment outcomes and minimise adverse events. Further research may lead to pre-treatment assessment of both tumour and patient-associated biomarkers and personalised multimodal prehabilitation care plans, as well as on-treatment support with targeted nutrition, physical activity, and supplementation regimes, including both systemic inflammation and gut microbiome modulating strategies. Given the emerging understanding of chronic stress impact on ICI treatment outcomes, mind-body approaches require further investigation.

The Hammersmith Score Optimises Patient Selection and Predicts for Overall Survival in Early-Phase Cancer Trial Participants Independent of Tumour Burden.

INTRODUCTION: As tumour response rates are increasingly demonstrated in early-phase cancer trials (EPCT), optimal patient selection and accurate prognostication are paramount. Hammersmith Score (HS), a simple prognostic index derived on routine biochemical measures (albumin <35 g/L, lactate dehydrogenase >450 IU/L, sodium <135 mmol/L), is a validated predictor of response and survival in EPCT participants. HS has not been validated in the cancer immunotherapy era. METHODS: We retrospectively analysed characteristics and outcomes of unselected referrals to our early-phase unit (12/2019-12/2022). Independent predictors for overall survival (OS) were identified from univariable and multivariable models. HS was calculated for 66 eligible trial participants and compared with the Royal Marsden Score (RMS) to predict OS. Multivariable logistic regression and C-index was used to compare predictive ability of prognostic models. RESULTS: Of 212 referrals, 147 patients were screened and 82 patients treated in EPCT. Prognostic stratification by HS identifies significant difference in median OS, and HS was confirmed as a multivariable predictor for OS (HR: HS 1 vs. 0 2.51, 95% CI: 1.01-6.24, p = 0.049; HS 2/3 vs. 0: 10.32, 95% CI: 2.15-49.62, p = 0.004; C-index 0.771) with superior multivariable predictive ability than RMS (HR: RMS 2 vs. 0/1 5.46, 95% CI: 1.12-26.57, p = 0.036; RMS 3 vs. 0/1 6.83, 95% CI: 1.15-40.53, p < 0.001; C-index 0.743). CONCLUSIONS: HS is a validated prognostic index for patients with advanced cancer treated in the context of modern EPCTs, independent of tumour burden. HS is a simple, inexpensive prognostic tool to optimise referral for EPCT.

From the European Medicines Agency to Project Orbis: new activities and challenges to facilitate UK oncology drug approval following Brexit.

The departure of the UK from the European Union (EU) and affiliated European regulatory bodies, including the European Medicines Agency, on Dec 31, 2020, has resulted in the Medicines and Healthcare products Regulatory Agency becoming an independent national regulator. This change has required a fundamental transformation of the UK drug regulatory landscape, creating both opportunities and challenges for future development of oncology drugs. New UK pharmaceutical policies have sought to make the UK an attractive market for drug development and regulatory review, by offering expedited review pathways coupled to strong collaborative relations with other leading international medicines regulators, outside of Europe. Oncology is a key global therapy area for both drug development and regulatory approval, and the UK Government has been keen to show regulatory innovation and international collaboration through approval of new cancer medicines. In this Policy Review, we examine the new UK regulatory frameworks, policies, and global collaborations affecting new oncology drug approvals after departure from the EU. We explore some of the challenges that might lie ahead as the UK creates new and independent regulatory review and approval processes for the next generation of cancer medicines.

A randomized phase 2 study of sapanisertib in combination with paclitaxel versus paclitaxel alone in women with advanced, recurrent, or persistent endometrial cancer.

OBJECTIVE: This phase 2 study investigated sapanisertib (selective dual inhibitor of mTORC1/2) alone, or in combination with paclitaxel or TAK-117 (a selective small molecule inhibitor of PI3K), versus paclitaxel alone in advanced, recurrent, or persistent endometrial cancer. METHODS: Patients with histologic diagnosis of endometrial cancer (1-2 prior regimens) were randomized to 28-day cycles on four treatment arms: 1) weekly paclitaxel 80 mg/m2 (days 1, 8, and 15); 2) weekly paclitaxel 80 mg/m2 + oral sapanisertib 4 mg on days 2-4, 9-11, 16-18, and 23-25; 3) weekly sapanisertib 30 mg, or 4) sapanisertib 4 mg + TAK-117 200 mg on days 1-3, 8-10, 15-17, and 22-24. RESULTS: Of 241 patients randomized, 234 received treatment (paclitaxel, n = 87 [3 ongoing]; paclitaxel+sapanisertib, n = 86 [3 ongoing]; sapanisertib, n = 41; sapanisertib+TAK-117, n = 20). The sapanisertib and sapanisertib+TAK-117 arms were closed to enrollment after futility analyses. After a median follow-up of 14.4 (paclitaxel) versus 17.2 (paclitaxel+sapanisertib) months, median progression-free survival (PFS; primary endpoint) was 3.7 versus 5.6 months (hazard ratio [HR] 0.82; 95% confidence interval [CI] 0.58-1.15; p = 0.139); in patients with endometrioid histology (n = 116), median PFS was 3.3 versus 5.7 months (HR 0.66; 95% CI 0.43-1.03). Grade ≥ 3 treatment-emergent adverse event rates were 54.0% with paclitaxel versus 89.5% paclitaxel+sapanisertib. CONCLUSIONS: Our findings support inclusion of chemotherapy combinations with investigational agents for advanced or metastatic disease. The primary endpoint was not met and toxicity was manageable. TRIAL REGISTRATION: ClinicalTrials.gov number, NCT02725268.

Bile Microbiome Signatures Associated with Pancreatic Ductal Adenocarcinoma Compared to Benign Disease: A UK Pilot Study.

Pancreatic ductal adenocarcinoma (PDAC) has a very poor survival. The intra-tumoural microbiome can influence pancreatic tumourigenesis and chemoresistance and, therefore, patient survival. The role played by bile microbiota in PDAC is unknown. We aimed to define bile microbiome signatures that can effectively distinguish malignant from benign tumours in patients presenting with obstructive jaundice caused by benign and malignant pancreaticobiliary disease. Prospective bile samples were obtained from 31 patients who underwent either Endoscopic Retrograde Cholangiopancreatography (ERCP) or Percutaneous Transhepatic Cholangiogram (PTC). Variable regions (V3-V4) of the 16S rRNA genes of microorganisms present in the samples were amplified by Polymerase Chain Reaction (PCR) and sequenced. The cohort consisted of 12 PDAC, 10 choledocholithiasis, seven gallstone pancreatitis and two primary sclerosing cholangitis patients. Using the 16S rRNA method, we identified a total of 135 genera from 29 individuals (12 PDAC and 17 benign). The bile microbial beta diversity significantly differed between patients with PDAC vs. benign disease (Permanova p = 0.0173). The separation of PDAC from benign samples is clearly seen through unsupervised clustering of Aitchison distance. We found three genera to be of significantly lower abundance among PDAC samples vs. benign, adjusting for false discovery rate (FDR). These were Escherichia (FDR = 0.002) and two unclassified genera, one from Proteobacteria (FDR = 0.002) and one from Enterobacteriaceae (FDR = 0.011). In the same samples, the genus Streptococcus (FDR = 0.033) was found to be of increased abundance in the PDAC group. We show that patients with obstructive jaundice caused by PDAC have an altered microbiome composition in the bile compared to those with benign disease. These bile-based microbes could be developed into potential diagnostic and prognostic biomarkers for PDAC and warrant further investigation.

Surgery due to mechanical bowel obstruction in relapsed ovarian cancer: clinical and surgical results of a bicentric analysis of 87 patients.

INTRODUCTION: Mechanical bowel obstruction is a frequent acute and life-threatening event in relapsed ovarian cancer. Salvage surgery after failure of all conservative approaches, resulting in short bowel syndrome (SBS) constitutes a therapeutic dilemma. Our aim was to evaluate patients' surgical and clinical outcome in these highly palliative situations. Previous, limited, data reported a high morbidity and mortality. However, recent surgical and therapeutical improvements in relapsed ovarian cancer (ROC) offer better identification of patients who might benefit from surgery in an effort to extend the window of opportunity to subsequently offer these patients novel systemic therapeutic approaches. MATERIAL AND METHODS: All subsequent ROC patients between 2012 and 2017 with acute mechanical bowel obstruction who underwent salvage extraperitoneal en bloc intestinal resection were retrospectively identified. Data were collected from two ESGO certified Ovarian Cancer Centers of Excellence (Charité Berlin and Imperial College London) and systematically evaluated regarding surgical and clinical outcomes. RESULTS: Overall, 87 ROC patients were included in the analysis (median age 56 years, range 24-88), 47% were platinum resistant. High grade serous was the most common histology (76%) while most of the patients (67%) had at least two previous lines of treatment. Mean observed OS was 7.8 months. After salvage surgery, 46% of the patients had a residual small bowel length < 180 cm and 18% > 180 cm resulting in 41% in need of total parental nutrition. In 80% of the patients a permanent stoma was necessary. 30d morbidity and mortality was 74% and 10%, respectively. More than half of the patients were able to receive further courses of chemotherapy after surgery. DISCUSSION: Salvage surgery for bowel obstruction in ROC patients needs careful consideration and identification of optimal surgical candidates to have the maximal therapeutic benefit. Despite the challenging morbidity profile, most patients managed to proceed to subsequent novel and conventional systemic treatment and so have their window of therapeutic opportunity extended.

The Clinical Significance of Transfer RNAs Present in Extracellular Vesicles.

Extracellular vesicles (EVs) are important for intercellular signalling in multi-cellular organisms. However, the role of mature transfer RNAs (tRNAs) and tRNA fragments in EVs has yet to be characterised. This systematic review aimed to identify up-to-date literature on tRNAs present within human EVs and explores their potential clinical significance in health and disease. A comprehensive and systematic literature search was performed, and the study was conducted in accordance with PRISMA guidelines. Electronic databases MEDLINE and EMBASE were searched up until 1 January 2022. From 685 papers, 60 studies were identified for analysis. The majority of papers reviewed focussed on the role of EV tRNAs in cancers (31.7%), with numerous other conditions represented. Blood and cell lines were the most common EV sources, representing 85.9% of protocols used. EV isolation methods included most known methods, precipitation being the most common (49.3%). The proportion of EV tRNAs was highly variable, ranging between 0.04% to >95% depending on tissue source. EV tRNAs are present in a multitude of sources and show promise as disease markers in breast cancer, gastrointestinal cancers, and other diseases. EV tRNA research is an emerging field, with increasing numbers of papers highlighting novel methodologies for tRNA and tRNA fragment discovery.

Objective responses to first-line neoadjuvant carboplatin-paclitaxel regimens for ovarian, fallopian tube, or primary peritoneal carcinoma (ICON8): post-hoc exploratory analysis of a randomised, phase 3 trial.

BACKGROUND: Platinum-based neoadjuvant chemotherapy followed by delayed primary surgery (DPS) is an established strategy for women with newly diagnosed, advanced-stage epithelial ovarian cancer. Although this therapeutic approach has been validated in randomised, phase 3 trials, evaluation of response to neoadjuvant chemotherapy using Response Evaluation Criteria in Solid Tumors, version 1.1 (RECIST), and cancer antigen 125 (CA125) has not been reported. We describe RECIST and Gynecologic Cancer InterGroup (GCIG) CA125 responses in patients receiving platinum-based neoadjuvant chemotherapy followed by DPS in the ICON8 trial. METHODS: ICON8 was an international, multicentre, randomised, phase 3 trial done across 117 hospitals in the UK, Australia, New Zealand, Mexico, South Korea, and Ireland. The trial included women aged 18 years or older with an Eastern Cooperative Oncology Group performance status of 0-2, life expectancy of more than 12 weeks, and newly diagnosed International Federation of Gynecology and Obstetrics (FIGO; 1988) stage IC-IIA high-grade serous, clear cell, or any poorly differentiated or grade 3 histological subtype, or any FIGO (1988) stage IIB-IV epithelial cancer of the ovary, fallopian tube, or primary peritoneum. Patients were randomly assigned (1:1:1) to receive intravenous carboplatin (area under the curve [AUC]5 or AUC6) and intravenous paclitaxel (175 mg/m2 by body surface area) on day 1 of every 21-day cycle (control group; group 1); intravenous carboplatin (AUC5 or AUC6) on day 1 and intravenous dose-fractionated paclitaxel (80 mg/m2 by body surface area) on days 1, 8, and 15 of every 21-day cycle (group 2); or intravenous dose-fractionated carboplatin (AUC2) and intravenous dose-fractionated paclitaxel (80 mg/m2 by body surface area) on days 1, 8, and 15 of every 21-day cycle (group 3). The maximum number of cycles of chemotherapy permitted was six. Randomisation was done with a minimisation method, and patients were stratified according to GCIG group, disease stage, and timing and outcome of cytoreductive surgery. Patients and clinicians were not masked to group allocation. The scheduling of surgery and use of neoadjuvant chemotherapy were determined by local multidisciplinary case review. In this post-hoc exploratory analysis of ICON8, progression-free survival was analysed using the landmark method and defined as the time interval between the date of pre-surgical planning radiological tumour assessment to the date of investigator-assessed clinical or radiological progression or death, whichever occurred first. This definition is different from the intention-to-treat primary progression-free survival analysis of ICON8, which defined progression-free survival as the time from randomisation to the date of first clinical or radiological progression or death, whichever occurred first. We also compared the extent of surgical cytoreduction with RECIST and GCIG CA125 responses. This post-hoc exploratory analysis includes only women recruited to ICON8 who were planned for neoadjuvant chemotherapy followed by DPS and had RECIST and/or GCIG CA125-evaluable disease. ICON8 is closed for enrolment and follow-up, and registered with ClinicalTrials.gov, NCT01654146. FINDINGS: Between June 6, 2011, and Nov 28, 2014, 1566 women were enrolled in ICON8, of whom 779 (50%) were planned for neoadjuvant chemotherapy followed by DPS. Median follow-up was 29·5 months (IQR 15·6-54·3) for the neoadjuvant chemotherapy followed by DPS population. Of 564 women who had RECIST-evaluable disease at trial entry, 348 (62%) had a complete or partial response. Of 727 women who were evaluable by GCIG CA125 criteria at the time of diagnosis, 610 (84%) had a CA125 response. Median progression-free survival was 14·4 months (95% CI 9·2-28·0; 297 events) for patients with a RECIST complete or partial response and 13·3 months (8·1-20·1; 171 events) for those with RECIST stable disease. Median progression-free survival for women with a GCIG CA125 response was 13·8 months (95% CI 8·8-23·4; 544 events) and 9·7 months (5·8-14·5; 111 events) for those without a GCIG CA125 response. Complete cytoreduction (R0) was achieved in 187 (56%) of 335 women with a RECIST complete or partial response and 73 (42%) of 172 women with RECIST stable disease. Complete cytoreduction was achieved in 290 (50%) of 576 women with a GCIG CA125 response and 30 (30%) of 101 women without a GCIG CA125 response. INTERPRETATION: The RECIST-defined radiological response rate was lower than that frequently quoted to patients in the clinic. RECIST and GCIG CA125 responses to neoadjuvant chemotherapy for epithelial ovarian cancer should not be used as individual predictive markers to stratify patients who are likely to benefit from DPS, but instead used in conjunction with the patient's clinical capacity to undergo cytoreductive surgery. A patient should not be denied surgery based solely on the lack of a RECIST or GCIG CA125 response. FUNDING: Cancer Research UK, UK Medical Research Council, Health Research Board in Ireland, Irish Cancer Society, and Cancer Australia.

The application of metabolomics in ovarian cancer management: a systematic review.

Metabolomics, the global analysis of metabolites in a biological specimen, could potentially provide a fast method of biomarker identification for ovarian cancer. This systematic review aims to examine findings from studies that apply metabolomics to the diagnosis, prognosis, treatment, and recurrence of ovarian cancer. A systematic search of English language publications was conducted on PubMed, Science Direct, and SciFinder. It was augmented by a snowball strategy, whereby further relevant studies are identified from reference lists of included studies. Studies in humans with ovarian cancer which focus on metabolomics of biofluids and tumor tissue were included. No restriction was placed on the time of publication. A separate review of targeted metabolomic studies was conducted for completion. Qualitative data were summarized in a comprehensive table. The studies were assessed for quality and risk of bias using the ROBINS-I tool. 32 global studies were included in the main systematic review. Most studies applied metabolomics to diagnosing ovarian cancer, within which the most frequently reported metabolite changes were a down-regulation of phospholipids and amino acids: histidine, citrulline, alanine, and methionine. Dysregulated phospholipid metabolism was also reported in the separately reviewed 18 targeted studies. Generally, combinations of more than one significant metabolite as a panel, in different studies, achieved a higher sensitivity and specificity for diagnosis than a single metabolite; for example, combinations of different phospholipids. Widespread metabolite differences were observed in studies examining prognosis, treatment, and recurrence, and limited conclusions could be drawn. Cellular processes of proliferation and invasion may be reflected in metabolic changes present in poor prognosis and recurrence. For example, lower levels of lysine, with increased cell invasion as an underlying mechanism, or glutamine dependency of rapidly proliferating cancer cells. In conclusion, this review highlights potential metabolites and biochemical pathways which may aid the clinical care of ovarian cancer if further validated.

TP53 regulates miRNA association with AGO2 to remodel the miRNA-mRNA interaction network.

DNA damage activates TP53-regulated surveillance mechanisms that are crucial in suppressing tumorigenesis. TP53 orchestrates these responses directly by transcriptionally modulating genes, including microRNAs (miRNAs), and by regulating miRNA biogenesis through interacting with the DROSHA complex. However, whether the association between miRNAs and AGO2 is regulated following DNA damage is not yet known. Here, we show that, following DNA damage, TP53 interacts with AGO2 to induce or reduce AGO2's association of a subset of miRNAs, including multiple let-7 family members. Furthermore, we show that specific mutations in TP53 decrease rather than increase the association of let-7 family miRNAs, reducing their activity without preventing TP53 from interacting with AGO2. This is consistent with the oncogenic properties of these mutants. Using AGO2 RIP-seq and PAR-CLIP-seq, we show that the DNA damage-induced increase in binding of let-7 family members to the RISC complex is functional. We unambiguously determine the global miRNA-mRNA interaction networks involved in the DNA damage response, validating them through the identification of miRNA-target chimeras formed by endogenous ligation reactions. We find that the target complementary region of the let-7 seed tends to have highly fixed positions and more variable ones. Additionally, we observe that miRNAs, whose cellular abundance or differential association with AGO2 is regulated by TP53, are involved in an intricate network of regulatory feedback and feedforward circuits. TP53-mediated regulation of AGO2-miRNA interaction represents a new mechanism of miRNA regulation in carcinogenesis.

Maximal-Effort Cytoreductive Surgery for Ovarian Cancer Patients with a High Tumor Burden: Variations in Practice and Impact on Outcome.

BACKGROUND: This study aimed to compare the outcomes of two distinct patient populations treated within two neighboring UK cancer centers (A and B) for advanced epithelial ovarian cancer (EOC). METHODS: A retrospective analysis of all new stages 3 and 4 EOC patients treated between January 2013 and December 2014 was performed. The Mayo Clinic surgical complexity score (SCS) was applied. Cox regression analysis identified the impact of treatment methods on survival. RESULTS: The study identified 249 patients (127 at center A and 122 in centre B) without significant differences in International Federation of Gynecology and Obstetrics (FIGO) stage (FIGO 4, 29.7% at centers A and B), Eastern Cooperative Oncology Group (ECOG) performance status (ECOG < 2, 89.9% at centers A and B), or histology (serous type in 84.1% at centers A and B). The patients at center A were more likely to undergo surgery (87% vs 59.8%; p < 0.001). The types of chemotherapy and the patients receiving palliative treatment alone were equivalent between the two centers (3.6%). The median SCS was significantly higher at center A (9 vs 2; p < 0.001) with greater tumor burden (9 vs 6 abdominal fields involved; p < 0.001), longer median operation times (285 vs 155 min; p < 0.001), and longer hospital stays (9 vs 6 days; p < 0.001), but surgical morbidity and mortality were equivalent. The independent predictors of reduced overall survival (OS) were non-serous histology (hazard ratio [HR], 1.6; 95% confidence interval [CI] 1.04-2.61), ECOG higher than 2 (HR, 1.9; 95% CI 1.15-3.13), and palliation alone (HR, 3.43; 95% CI 1.51-7.81). Cytoreduction, of any timing, had an independent protective impact on OS compared with chemotherapy alone (HR, 0.31 for interval surgery and 0.39 for primary surgery), even after adjustment for other prognostic factors. CONCLUSIONS: Incorporating surgery into the initial EOC management, even for those patients with a greater tumor burden and more disseminated disease, may require more complex procedures and more resources in terms of theater time and hospital stay, but seems to be associated with a significant prolongation of the patients overall survival compared with chemotherapy alone.

Sustained expression of miR-26a promotes chromosomal instability and tumorigenesis through regulation of CHFR.

MicroRNA 26a (miR-26a) reduces cell viability in several cancers, indicating that miR-26a could be used as a therapeutic option in patients. We demonstrate that miR-26a not only inhibits G1-S cell cycle transition and promotes apoptosis, as previously described, but also regulates multiple cell cycle checkpoints. We show that sustained miR-26a over-expression in both breast cancer (BC) cell lines and mouse embryonic fibroblasts (MEFs) induces oversized cells containing either a single-large nucleus or two nuclei, indicating defects in mitosis and cytokinesis. Additionally, we demonstrate that miR-26a induces aneuploidy and centrosome defects and enhances tumorigenesis. Mechanistically, it acts by targeting G1-S transition genes as well as genes involved in mitosis and cytokinesis such as CHFR, LARP1 and YWHAE. Importantly, we show that only the re-expression of CHFR in miR-26a over-expressing cells partially rescues normal mitosis and impairs the tumorigenesis exerted by miR-26a, indicating that CHFR represents an important miR-26a target in the regulation of such phenotypes. We propose that miR-26a delivery might not be a viable therapeutic strategy due to the potential deleterious oncogenic activity of this miRNA.

miR-515-5p controls cancer cell migration through MARK4 regulation.

Here, we show that miR-515-5p inhibits cancer cell migration and metastasis. RNA-seq analyses of both oestrogen receptor receptor-positive and receptor-negative breast cancer cells overexpressing miR-515-5p reveal down-regulation of NRAS, FZD4, CDC42BPA, PIK3C2B and MARK4 mRNAs. We demonstrate that miR-515-5p inhibits MARK4 directly 3' UTR interaction and that MARK4 knock-down mimics the effect of miR-515-5p on breast and lung cancer cell migration. MARK4 overexpression rescues the inhibitory effects of miR-515-5p, suggesting miR-515-5p mediates this process through MARK4 down-regulation. Furthermore, miR-515-5p expression is reduced in metastases compared to primary tumours derived from both in vivo xenografts and samples from patients with breast cancer. Conversely, miR-515-5p overexpression prevents tumour cell dissemination in a mouse metastatic model. Moreover, high miR-515-5p and low MARK4 expression correlate with increased breast and lung cancer patients' survival, respectively. Taken together, these data demonstrate the importance of miR-515-5p/MARK4 regulation in cell migration and metastasis across two common cancers.

A Review of Thoracic and Mediastinal Cytoreductive Techniques in Advanced Ovarian Cancer: Extending the Boundaries.

The aim of this study was to review the surgical and clinical outcomes of intrathoracic and mediastinal surgical cytoreduction in stage IV epithelial ovarian cancer (EOC). Relevant articles were identified from MEDLINE and EMBASE. Only analyses or reports that described actual intrathoracic cytoreduction via pleurectomy and/or resection of cardiophrenic/mediastinal lymph nodes were included. Imaging articles that merely described thoracic tumor patterns were excluded. A total of nine studies were identified, the oldest originating in 2007. Procedures described were transdiaphragmatic resection of cardiophrenic lymph nodes and pleural disease (n = 5) and video-assisted thoracoscopic and mediastinal tumorectomies including pleurectomy (n = 4). The number of operated patients ranged between 1 and 30 with complete cytoreduction rates ranging between 68 and 100%. No surgical deaths directly related to the thoracic cytoreduction were reported and only one patient (1/30) experienced a postoperative complication in terms of a pneumothorax. None of the studies presented a direct comparison of survival to patients with thoracic disease who did not undergo thoracic cytoreduction, and therefore the survival benefit of thoracic cytoreduction could not be quantified. In conclusion, thoracic cytoreduction in advanced EOC seems feasible and with acceptable morbidity while offering a better understanding of the extent of disease and hence allowing the tailoring of intraabdominal resections. Nevertheless, its direct impact on patients' survival by a potential overruling of a more adverse tumor biology remains to be established in larger-scale prospective and ideally randomized trials.

The role of TP53 in miRNA loading onto AGO2 and in remodelling the miRNA-mRNA interaction network.

BACKGROUND: DNA damage transactivates tumour protein p53 (TP53)-regulated surveillance, crucial in suppressing tumorigenesis. TP53 mediates this process directly by transcriptionally modulating gene and microRNA (miRNA) expression and indirectly by regulating miRNA biogenesis. However, the role of TP53 in regulating miRNA-AGO2 loading and global changes in AGO2 binding to its gene targets in response to DNA damage are unknown. These processes might be novel mechanisms by which TP53 regulates miRNAs in response to DNA damage. METHODS: To show the network of miRNA-mRNA interactions that occur in response to DNA damage, we stimulated TP53 wild-type and null cell-lines with doxorubicin and performed RNA sequencing from total RNA (RNA-Seq) and AGO2-immunoprecipitated RNA (AGO2-RIP-Seq). We used a combined AGO2 RIP-seq and AGO2 PAR-CLIP-seq (photoactivatable-ribonucleoside-enhanced cross-linking and immunoprecipitation) approach to determine the exact sites of interaction between the AGO2-bound miRNAs and their mRNA targets. FINDINGS: TP53 directly associated with AGO2, and induced and reduced loading of a subset of miRNAs, including the lethal 7 (let-7) miRNA family members, onto AGO2 in response to DNA damage. Although mutated TP53 maintained its capacity to interact with AGO2, it mediated unloading instead of loading of let-7 family miRNAs, thereby reducing their activity. We determined the miRNA-mRNA interaction networks involved in the response to DNA damage both in the presence and absence of TP53. Furthermore, we showed that miRNAs whose cellular abundance or differential loading onto AGO2 was regulated by TP53 were involved in an intricate network of regulatory feedback and feedforward circuits that fine-tuned gene expression levels in response to DNA damage to permit the repair of DNA damage or initiation of programmed cell death. INTERPRETATION: Control of AGO2 loading by TP53 is a new mechanism of miRNA regulation in carcinogenesis. FUNDING: UK Medical Research Council, Action Against Cancer.

Integrated molecular analysis to investigate the role of microRNAs in pancreatic tumour growth and progression.

BACKGROUND: MicroRNAs (miRNAs) are small non-coding RNAs involved in the post-transcriptional regulation of mRNAs and are aberrantly expressed in cancer with important roles in tumorigenesis. A broad analysis of the combined effects of altered activities of miRNAs in pancreatic ductal adenocarcinoma (PDAC) has not been done, and how miRNAs might affect tumour progression or patient outcomes is unclear. METHODS: We combined data from miRNA and mRNA expression profiles from PDAC and normal pancreas samples (each n=9) and used bioinformatic analyses to identify a miRNA-mRNA regulatory network in PDAC. We validated our findings in PDAC cell-lines (PANC-1, MIA PaCa-2, LPc006, and LPc167), subcutaneous PDAC xenografts in mice, and laser capture microdissected PDACs from patients (n=91). We used this information to identify miRNAs that contributed most to tumorigenesis. FINDINGS: We identified three miRNAs (miR-21, miR-23a, and miR-27a) that acted as cooperative repressors of a network of tumour suppressor genes that included PDCD4, BTG2, and NEDD4L. Inhibition of miR-21, miR-23a, and miR-27a had synergistic effects in reducing proliferation of PDAC cells in culture and the growth of xenograft tumours. The level of inhibition was greater than that of silencing oncomiR-21 alone. In PDACs from patients, high levels of the combination of miR-21, miR-23a, and miR-27a was a strong independent predictor of short overall survival after surgical resection (hazard ratio 3·21, 95% CI 1·78-5·78). High expression of this combination was also associated with a more aggressive tumour phenotype: more microscopic tumour infiltration at resection margin and increased perineural invasion. INTERPRETATION: In an integrated data analysis, we identified functional miRNA-mRNA interactions that contribute to PDAC growth. These findings indicate that miRNAs act together to promote tumour progression and that future therapeutic strategies might require inhibition of several miRNAs. Furthermore, high tumour expression of the miR-21, miR-23a, and miR-27a combination could have potential use in the future as a prognostic signature for patients with PDAC. FUNDING: Peel Medical Research Trust, Alliance Family Foundation, Action Against Cancer, National Institute for Health Research, Association for International Cancer Research, Jason Boas Fellowship, Imperial Biomedical Research Centre, Rosetrees Trust, Joseph Ettedgui Charitable Foundation.