19 results found
Aboagye E, Li Y, Inglese M, et al., 2021, Consideration of metabolite efflux in radiolabelled choline kinetics, Pharmaceutics, ISSN: 1999-4923
Hypoxia is a complex microenvironmental condition known to regulate choline kinase α (CHKA) activity and choline transport through transcription factor hypoxia-inducible factor-1α (HIF-1α) and, therefore may confound uptake of choline radiotracer[18F]fluoromethyl-[1,2-2H4]-choline ([18 F]-D4-FCH). The aim of this study was to investigate how hypoxia affects choline radiotracer dynamics. Three underlying mechanisms by which hypoxiacould potentially alter the uptake of the choline radiotracer, [18 F]-D4-FCH, were investigated: 18F-D4-FCH import, CHKA phosphorylation activity, and efflux of [18 F]-D4-FCH and its phosphorylated product [18F]-D4-FCHP. Effects of hypoxia on [18 F]-D4-FCH uptake were studied in CHKA-overexpressing cell lines of prostate cancer, PC-3, and breast cancer, MDA-MB-231 cells. Mechanisms of radiotracer efflux were assessed by cell uptake and immunofluorescence in vitro, and examined in vivo (N=24). Mathematical modelling methodology was further developed to verify efflux hypothesis using [18 F]-D4-FCH dynamic PET scans from non-small cell lung cancer (NSCLC) patients (N=17). We report a novel finding involving export of phosphorylated[18F]-D4-FCH, [18 F]-D4-FCHP, via HIF-1α-responsive efflux transporters including ABCB4 when HIF-1α level is augmented. This is supported by graphical analysis of human data with a compartmental model (M2T6k+k5) that accounts for efflux. Hypoxia/HIF-1α increases the efflux of phosphorylated radiolabelled choline species, thus supporting consideration of efflux in modelling of radiotracer dynamics.
Aboagye E, Wang N, Brickute D, et al., 2021, Novel non-congeneric derivatives of the choline kinase alpha inhibitor ICL-CCIC-0019, Pharmaceutics, Vol: 13, Pages: 1-17, ISSN: 1999-4923
Choline kinase alpha (CHKA) is a promising target for the development of cancer therapeutics. We have previously reported ICL-CCIC-0019, a potent CHKA inhibitor with high cellular activity but with some unfavorable pharmacological properties. In this work, we present an active analogue of ICL-CCIC-0019 bearing a piperazine handle (CK146) to facilitate further structural elaboration of the pharmacophore and thus improve the biological profile. Two different strategies were evaluated in this study: (1) a prodrug approach whereby selective CHKA inhibition could be achieved through modulating the activity of CK146, via the incorporation of an ε-(Ac) Lys motif, cleavable by elevated levels of histone deacetylase (HDAC) and cathepsin L (CTSL) in tumour cells; (2) a prostate-specific membrane antigen (PSMA) receptor targeted delivery strategy. Prodrug (CK145) and PSMA-targeted (CK147) derivatives were successfully synthesized and evaluated in vitro. While the exploitation of CK146 in those two strategies did not deliver the expected results, important and informative structure-activity relationships were observed and have been reported.
Lu H, Cunnea P, Nixon K, et al., 2021, Discovery of a biomarker candidate for surgical stratification in high-grade serous ovarian cancer, British Journal of Cancer, Vol: 124, Pages: 1286-1293, ISSN: 0007-0920
Background: Maximal effort cytoreductive surgery is associated with improved outcomes in advanced high-grade serous ovarian cancer (HGSOC). However, despite complete gross resection (CGR), there is a percentage of patients who will relapse and die early. The aim of this study is to identify potential candidate biomarkers to help personalise surgical radicality.Methods: 136 advanced HGSOC cases who underwent CGR were identified from three public transcriptomic datasets. Candidate prognostic biomarkers were discovered in this cohort by Cox regression analysis, and further validated by targeted RNA-sequencing in HGSOC cases from Imperial College Healthcare NHS Trust (n = 59), and a public dataset. Gene set enrichment analysis was performed to understand the biological significance of the candidate biomarker.Results: We identified ALG5 as a prognostic biomarker for early tumour progression in advanced HGSOC despite CGR (HR = 2.42, 95% CI (1.57–3.75), p < 0.0001). The prognostic value of this new candidate biomarker was additionally confirmed in two independent datasets (HR = 1.60, 95% CI (1.03–2.49), p = 0.0368; HR = 3.08, 95% CI (1.07–8.81), p = 0.0365). Mechanistically, the oxidative phosphorylation was demonstrated as a potential biological pathway of ALG5-high expression in patients with early relapse (p < 0.001).Conclusion: ALG5 has been identified as an independent prognostic biomarker for poor prognosis in advanced HGSOC patients despite CGR. This sets a promising platform for biomarker combinations and further validations towards future personalised surgical care.
Antonowicz S, Bodai Z, Wiggins T, et al., 2021, Endogenous aldehyde accumulation generates genotoxicity and exhaled biomarkers in esophageal adenocarcinoma, NATURE COMMUNICATIONS, Vol: 12, ISSN: 2041-1723
Hu Z, Cunnea P, Zhong Z, et al., 2021, The Oxford Classic links epithelial-to-mesenchymal transition to immunosuppression in poor prognosis ovarian cancers, Clinical Cancer Research, Vol: 27, Pages: 1570-1579, ISSN: 1078-0432
Purpose: Using RNA sequencing, we recently developed the 52-gene–based Oxford classifier of carcinoma of the ovary (Oxford Classic, OxC) for molecular stratification of serous ovarian cancers (SOCs) based on the molecular profiles of their cell of origin in the fallopian tube epithelium. Here, we developed a 52-gene NanoString panel for the OxC to test the robustness of the classifier.Experimental Design: We measured the expression of the 52 genes in an independent cohort of prospectively collected SOC samples (n = 150) from a homogenous cohort who were treated with maximal debulking surgery and chemotherapy. We performed data mining of published expression profiles of SOCs and validated the classifier results on tissue arrays comprising 137 SOCs.Results: We found evidence of profound nongenetic heterogeneity in SOCs. Approximately 20% of SOCs were classified as epithelial-to-mesenchymal transition–high (EMT-high) tumors, which were associated with poor survival. This was independent of established prognostic factors, such as tumor stage, tumor grade, and residual disease after surgery (HR, 3.3; P = 0.02). Mining expression data of 593 patients revealed a significant association between the EMT scores of tumors and the estimated fraction of alternatively activated macrophages (M2; P < 0.0001), suggesting a mechanistic link between immunosuppression and poor prognosis in EMT-high tumors.Conclusions: The OxC-defined EMT-high SOCs carry particularly poor prognosis independent of established clinical parameters. These tumors are associated with high frequency of immunosuppressive macrophages, suggesting a potential therapeutic target to improve clinical outcome.
Natoli M, Gallon J, Lu H, et al., 2021, Transcriptional analysis of multiple ovarian cancer cohorts reveals prognostic and immunomodulatory consequences of ERV expression, Journal for ImmunoTherapy of Cancer, Vol: 9, ISSN: 2051-1426
Background Endogenous retroviruses (ERVs) play a role in a variety of biological processes, including embryogenesis and cancer. DNA methyltransferase inhibitors (DNMTi)-induced ERV expression triggers interferon responses in ovarian cancer cells via the viral sensing machinery. Baseline expression of ERVs also occurs in cancer cells, though this process is poorly understood and previously unexplored in epithelial ovarian cancer (EOC). Here, the prognostic and immunomodulatory consequences of baseline ERV expression was assessed in EOC.Methods ERV expression was assessed using EOC transcriptional data from The Cancer Genome Atlas (TCGA) and from an independent cohort (Hammersmith Hospital, HH), as well as from untreated or DNMTi-treated EOC cell lines. Least absolute shrinkage and selection operator (LASSO) logistic regression defined an ERV expression score to predict patient prognosis. Immunohistochemistry (IHC) was conducted on the HH cohort. Combination of DNMTi treatment with γδ T cells was tested in vitro, using EOC cell lines and patient-derived tumor cells.Results ERV expression was found to define clinically relevant subsets of EOC patients. An ERV prognostic score was successfully generated in TCGA and validated in the independent cohort. In EOC patients from this cohort, a high ERV score was associated with better survival (log-rank p=0.0009) and correlated with infiltration of CD8+PD1+T cells (r=0.46, p=0.0001). In the TCGA dataset, a higher ERV score was found in BRCA1/2 mutant tumors, compared to wild type (p=0.015), while a lower ERV score was found in CCNE1 amplified tumors, compared to wild type (p=0.019). In vitro, baseline ERV expression dictates the level of ERV induction in response to DNMTi. Manipulation of an ERV expression threshold by DNMTi resulted in improved EOC cell killing by cytotoxic immune cells.Conclusions These findings uncover the potential for baseline ERV expression to robustly inform EOC patient prognosis, influence
Aboagye E, Sharma R, Inglese M, et al., 2020, Monitoring response to transarterial chemoembolization in hepatocellular carcinoma using 18F-Fluorothymidine Positron Emission Tomography, The Journal of Nuclear Medicine, Vol: 61, Pages: 1743-1748, ISSN: 0161-5505
Accurate disease monitoring is essential following transarterial chemoembolization (TACE) in hepatocellular carcinoma (HCC) due to potential for profound adverse event and large variation in survival outcome. Post-treatment changes on conventional imaging can confound determination of residual/recurrent disease, magnifying the clinical challenge. Based on increased expression of thymidylate synthase (TYMS), thymidine kinase-1 (TK-1) and SLC29A1 (Equilibrative nucleoside transporter 1, ENT1) in HCC compared with liver tissue, we conducted a proof of concept study evaluating the efficacy of 18F-fluorothymidine (18F-FLT)-PET to assess response to TACE. As previous PET studies in HCC have been hampered by high background liver signal, we investigated if a temporal-intensity voxel-clustering (“Kinetic Spatial Filtering”) (KSF) improved lesion detection. Methods: A tissue microarray (TMA) was built from 36 HCC samples and matched surrounding cirrhotic tissue and was stained for thymidine kinase-1 (TK-1). A prospective study was conducted; eighteen patients with a diagnosis of HCC by American Association for the Study of Liver Diseases criteria (AALSD) who were eligible to treatment with TACE were enrolled. Patients underwent baseline conventional imaging and dynamic 18F-FLT-PET/KSF followed by TACE. Repeat imaging was performed 6-8 weeks post TACE. PET parameters were compared with modified-Response Evaluation in Solid Tumours (mRECIST) enhancement-based criteria. Results: Cancer Genome Atlas analysis revealed increased RNA expression of TYMS, TK-1 and SLC29A1 in HCC. TK-1 protein expression was significantly higher in HCC (p<0.05). The sensitivity of 18F-FLT-PET for baseline HCC detection was 73% (SUVmax of 9.7 ± 3.0; tumour to liver ratio of 1.2 ± 0.3). Application of KSF did not improve lesion detection. Lesion response following TACE by mRECIST criteria was 58% (14 patients with 24 lesions). A 30% reduction in mean 18F-FLT-PET uptake was o
Raglan O, Assi N, Nautiyal J, et al., 2020, Proteomic analysis of malignant and benign endometrium according to obesity and insulin-resistance status using Reverse Phase Protein Array, Publisher: ELSEVIER SCIENCE INC, Pages: 57-72, ISSN: 1931-5244
Avesani G, Arshad M, Lu H, et al., 2020, Radiological assessment of Peritoneal Cancer Index on preoperative CT in ovarian cancer is related to surgical outcome and survival, RADIOLOGIA MEDICA, Vol: 125, Pages: 770-776, ISSN: 0033-8362
Raglan O, Assi N, Nautiyal J, et al., 2019, Proteomic analysis of malignant and benign endometrium according to obesity and insulin resistance status using Reverse Phase Protein Array, Translational Research: the journal of laboratory and clinical medicine, ISSN: 0022-2143
Obesity and hyperinsulinemia are known risk factors for endometrial cancer, yet thebiological pathways underlying this relationship are incompletely understood. Thisstudy investigated protein expression in endometrial cancer and benign tissue andits correlation with obesity and insulin resistance.One hundred and seven women undergoing hysterectomy for endometrial canceror benign conditions provided a fasting blood sample and endometrial tissue. Weperformed proteomic expression according to body mass index, insulin resistance,and serum marker levels. We used linear regression and independentttest for statis-tical analysis. Proteomic data from 560 endometrial cancer cases from The CancerGenome Atlas (TCGA) databank were used to assess reproducibility of results.One hundred and twenty seven proteins were significantly differentially expressedbetween 66 cancer and 26 benign patients. Protein expression involved in cellcycle progression, impacting cytoskeletal dynamics (PAK1) and cell survival (Rab25), were most significantly altered. Obese women with cancer had increasedPRAS40_pT246; a downstream marker of increased PI3K-AKT signaling. Obesewomen without cancer had increased mitogenic and antiapoptotic signaling byway of upregulation of Mcl-1, DUSP4, and Insulin Receptor-b.This exploratory study identified a number of candidate proteins specific to endo-metrioid endometrial cancer and benign endometrial tissues. Obesity and insulinresistance in women with benign endometrium leads to specific upregulation ofproteins involved in insulin and driver oncogenic signaling pathways such as thePI3K-AKT-mTOR and growth factor signaling pathways which are mitogenic andalso disruptive to metabolism. (Translational Research 2020; 000:1 16)
Birtley JR, Alomary M, Zanini E, et al., 2019, Inactivating mutations and X-ray crystal structure of the tumor suppressor OPCML reveal cancer-associated functions, Nature Communications, Vol: 10, ISSN: 2041-1723
OPCML, a tumor suppressor gene, is frequently silenced epigenetically in ovarian and other cancers. Here we report, by analysis of databases of tumor sequences, the observation of OPCML somatic missense mutations from various tumor types and the impact of these mutations on OPCML function, by solving the X-ray crystal structure of this glycoprotein to 2.65 Å resolution. OPCML consists of an extended arrangement of three immunoglobulin-like domains and homodimerizes via a network of contacts between membrane-distal domains. We report the generation of a panel of OPCML variants with representative clinical mutations and demonstrate clear phenotypic effects in vitro and in vivo including changes to anchorage-independent growth, interaction with activated cognate receptor tyrosine kinases, cellular migration, invasion in vitro and tumor growth in vivo. Our results suggest that clinically occurring somatic missense mutations in OPCML have the potential to contribute to tumorigenesis in a variety of cancers.
Lu H, Arshad M, Thornton A, et al., 2019, A mathematical-descriptor of tumor-mesoscopic-structure from computed-tomography images annotates prognostic and molecular-phenotypes of epithelial ovarian cancer, Nature Communications, Vol: 10, ISSN: 2041-1723
The five-year survival rate of epithelial ovarian cancer (EOC) is approximately 35–40% despite maximal treatment efforts, highlighting a need for stratification biomarkers for personalized treatment. Here we extract 657 quantitative mathematical descriptors from the preoperative CT images of 364 EOC patients at their initial presentation. Using machine learning, we derive a non-invasive summary-statistic of the primary ovarian tumor based on 4 descriptors, which we name “Radiomic Prognostic Vector” (RPV). RPV reliably identifies the 5% of patients with median overall survival less than 2 years, significantly improves established prognostic methods, and is validated in two independent, multi-center cohorts. Furthermore, genetic, transcriptomic and proteomic analysis from two independent datasets elucidate that stromal phenotype and DNA damage response pathways are activated in RPV-stratified tumors. RPV and its associated analysis platform could be exploited to guide personalized therapy of EOC and is potentially transferrable to other cancer types.
Arshad MA, Thornton A, Lu H, et al., 2019, Discovery of pre-therapy 2-deoxy-2-F-18-fluoro-D-glucose positron emission tomography-based radiomics classifiers of survival outcome in non-small-cell lung cancer patients, European Journal of Nuclear Medicine and Molecular Imaging, Vol: 46, Pages: 455-466, ISSN: 0340-6997
PurposeThe aim of this multi-center study was to discover and validate radiomics classifiers as image-derived biomarkers for risk stratification of non-small-cell lung cancer (NSCLC).Patients and methodsPre-therapy PET scans from a total of 358 Stage I–III NSCLC patients scheduled for radiotherapy/chemo-radiotherapy acquired between October 2008 and December 2013 were included in this seven-institution study. A semi-automatic threshold method was used to segment the primary tumors. Radiomics predictive classifiers were derived from a training set of 133 scans using TexLAB v2. Least absolute shrinkage and selection operator (LASSO) regression analysis was used for data dimension reduction and radiomics feature vector (FV) discovery. Multivariable analysis was performed to establish the relationship between FV, stage and overall survival (OS). Performance of the optimal FV was tested in an independent validation set of 204 patients, and a further independent set of 21 (TESTI) patients.ResultsOf 358 patients, 249 died within the follow-up period [median 22 (range 0–85) months]. From each primary tumor, 665 three-dimensional radiomics features from each of seven gray levels were extracted. The most predictive feature vector discovered (FVX) was independent of known prognostic factors, such as stage and tumor volume, and of interest to multi-center studies, invariant to the type of PET/CT manufacturer. Using the median cut-off, FVX predicted a 14-month survival difference in the validation cohort (N = 204, p = 0.00465; HR = 1.61, 95% CI 1.16–2.24). In the TESTI cohort, a smaller cohort that presented with unusually poor survival of stage I cancers, FVX correctly indicated a lack of survival difference (N = 21, p = 0.501). In contrast to the radiomics classifier, clinically routine PET variables including SUVmax, SUVmean and SUVpeak lacked any prognostic information.ConclusionPET-based radiomics classifiers deriv
Marinho AT, Lu H, Pereira SA, et al., 2019, Anti-tumorigenic and platinum-sensitizing effects of apolipoprotein A1 and apolipoprotein A1 mimetic peptides in ovarian cancer, Frontiers in Pharmacology, Vol: 9, ISSN: 1663-9812
Objective: Apolipoprotein A1 (ApoA1) is remarkably decreased in serum and ovarian tissues of ovarian cancer patients. ApoA1 and ApoA1 mimetic peptides can sequestrate pro-inflammatory phospholipids, some of which are known to activate a variety of oncogenic pathways. Besides, more intrinsic anti-tumorigenic properties, independent from interaction with lipids, have also been described for ApoA1. We aimed to disclose the effects of ApoA1 and a mimetic peptide on the malignant phenotype of ovarian cancer cells, particularly regarding cell viability, invasiveness and platinum sensitization.Methods: Cells viability was assessed by MTS assay. Extracellular matrix invasion was assessed by transwell and spheroid invasion assays. Western blotting was performed to evaluate the effect of test compounds on intracellular pathways. Sensitization assays were performed in vitro and in the biologically relevant in ovo chorioallantoic membrane model.Results: Both ApoA1 and the mimetic peptide, at a concentration of 100 μg/mL, were able to decrease the viability of SKOV3, CAOV3, and OVCAR3 cells (p < 0.05). The peptide at this concentration was not able to affect the viability of immortalized non-neoplastic ovarian cells (p > 0.05). ApoA1 decreased SKOV3 cells invasiveness at 300 μg/mL after 72 and 96 h of exposure (p < 0.05), while the ApoA1 mimetic peptide prevented cell invasion at 50 and 100 μg/mL (p < 0.01). Treatment with 100 μg/mL of ApoA1 mimetic peptide decreased Akt phosphorylation in SKOV3 cells (p < 0.01). Accordingly, treatment with increasing concentrations of the peptide sensitized SKOV3, OVCAR3 and CAOV3 cells to cisplatin. This synergistic effect was observed both in vitro and in ovo.Conclusions: These results support the role of ApoA1 and ApoA1 mimetics as suppressors of ovarian tumorigenesis and as chemo-sensitising agents.
Cunnea P, Gorgy T, Petkos K, et al., 2018, Clinical value of bioelectrical properties of cancerous tissue in advanced epithelial ovarian cancer patients, Scientific Reports, Vol: 8, Pages: 1-12, ISSN: 2045-2322
Currently, there are no valid pre-operatively established biomarkers or algorithms that can accurately predict surgical and clinical outcome for patients with advanced epithelial ovarian cancer (EOC). In this study, we suggest that profiling of tumour parameters such as bioelectrical-potential and metabolites, detectable by electronic sensors, could facilitate the future development of devices to better monitor disease and predict surgical and treatment outcomes. Biopotential was recorded, using a potentiometric measurement system, in ex vivo paired non-cancerous and cancerous omental tissues from advanced stage EOC (n = 36), and lysates collected for metabolite measurement by microdialysis. Consistently different biopotential values were detected in cancerous tissue versus non-cancerous tissue across all cases (p < 0.001). High tumour biopotential levels correlated with advanced tumour stage (p = 0.048) and tumour load, and negatively correlated with stroma. Within our EOC cohort and specifically the high-grade serous subtype, low biopotential levels associated with poorer progression-free survival (p = 0.0179, p = 0.0143 respectively). Changes in biopotential levels significantly correlated with common apoptosis related pathways. Lactate and glucose levels measured in paired tissues showed significantly higher lactate/glucose ratio in tissues with low biopotential (p < 0.01, n = 12). Our study proposes the feasibility of biopotential and metabolite monitoring as a biomarker modality profiling EOC to predict surgical and clinical outcomes.
Braga VMM, McCormack JJ, Bruche S, et al., 2017, The scaffold protein Ajuba suppresses CdGAP activity in epithelia to maintain stable cell-cell contacts, Scientific Reports, Vol: 7, ISSN: 2045-2322
Levels of active Rac1 at epithelial junctions are partially modulated via interaction with Ajuba, an actin binding and scaffolding protein. Here we demonstrate that Ajuba interacts with the Cdc42 GTPase activating protein CdGAP, a GAP for Rac1 and Cdc42, at cell-cell contacts. CdGAP recruitment to junctions does not require Ajuba; rather Ajuba seems to control CdGAP residence at sites of cell-cell adhesion. CdGAP expression potently perturbs junctions and Ajuba binding inhibits CdGAP activity. Ajuba interacts with Rac1 and CdGAP via distinct domains and can potentially bring them in close proximity at junctions to facilitate activity regulation. Functionally, CdGAP-Ajuba interaction maintains junctional integrity in homeostasis and diseases: (i) gain-of-function CdGAP mutants found in Adams-Oliver Syndrome patients strongly destabilize cell-cell contacts and (ii) CdGAP mRNA levels are inversely correlated with E-cadherin protein expression in different cancers. We present conceptual insights on how Ajuba can integrate CdGAP binding and inactivation with the spatio-temporal regulation of Rac1 activity at junctions. Ajuba poses a novel mechanism due to its ability to bind to CdGAP and Rac1 via distinct domains and influence the activation status of both proteins. This functional interplay may contribute towards conserving the epithelial tissue architecture at steady-state and in different pathologies.
Amoroso MR, Matassa DS, Agliarulo I, et al., 2016, TRAP1 downregulation in human ovarian cancer enhances invasion and epithelial-mesenchymal transition, Cell Death & Disease, Vol: 7, ISSN: 2041-4889
Ovarian cancer (OC) is the second leading cause of gynecological cancer death worldwide. Although the list of biomarkers is still growing, molecular mechanisms involved in OC development and progression remain elusive. We recently demonstrated that lower expression of the molecular chaperone TRAP1 in OC patients correlates with higher tumor grade and stage, and platinum resistance. Herein we show that TRAP1 is often deleted in high-grade serous OC patients (N=579), and that TRAP1 expression is correlated with the copy number, suggesting this could be one of the driving mechanisms for the loss of TRAP1 expression in OC. At molecular level, downregulation of TRAP1 associates with higher expression of p70S6K, a kinase frequently active in OC with emerging roles in cell migration and tumor metastasis. Indeed, TRAP1 silencing in different OC cells induces upregulation of p70S6K expression and activity, enhancement of cell motility and epithelial–mesenchymal transition (EMT). Consistently, in a large cohort of OC patients, TRAP1 expression is reduced in tumor metastases and directly correlates with the epithelial marker E-Cadherin, whereas it inversely correlates with the transcription factor Slug and the matrix metallopeptidases 2 and 9. Strikingly, pharmacological inhibition of p70S6K reverts the high motility phenotype of TRAP1 knock-down cells. However, although p70S6K inhibition or silencing reduces the expression of the transcription factors Snail and Slug, thus inducing upregulation of E-Cadherin expression, it is unable to revert EMT induced by TRAP1 silencing; furthermore, p70S6K did not show any significant correlation with EMT genes in patients, nor with overall survival or tumor stage, suggesting an independent and predominant role for TRAP1 in OC progression. Altogether, these results may provide novel approaches in OC with reduced TRAP1 expression, which could be resistant to therapeutic strategies based on the inhibition of the p70S6K pathway, with po
Matassa DS, Amoroso MR, Lu H, et al., 2016, Oxidative metabolism drives inflammation-induced platinum resistance in human ovarian cancer, Cell Death and Differentiation, Vol: 23, Pages: 1542-1554, ISSN: 1476-5403
Tumour cells have long been considered defective in mitochondrial respiration and mostly dependent on glycolytic metabolism. However, this assumption is currently challenged by several lines of evidence in a growing number of tumours. Ovarian cancer (OC) is one of the most lethal cancers worldwide, but it continues to be a poorly understood disease and its metabolic features are far to be elucidated. In this context, we investigated the role of tumour necrosis factor receptor-associated protein 1 (TRAP1), which is found upregulated in several cancer types and is a key modulator of tumour cell metabolism. Surprisingly, we found that TRAP1 expression inversely correlated with grade, stage and lower survival in a large cohort of OC patients. Accordingly, TRAP1 silencing induced resistance to cisplatin, resistant cells showed increased oxidative metabolism compared with their sensitive counterpart, and the bioenergetics cellular index of higher grade tumours indicated increased mitochondrial respiration. Strikingly, cisplatin resistance was reversible upon pharmacological inhibition of mitochondrial oxidative phosphorylation by metformin/oligomycin. At molecular level, increased oxidative metabolism in low TRAP1-expressing OC cells and tissues enhanced production of inflammatory mediators such as interleukin (IL)-6 and IL-8. Mechanistically, we identified members of the multidrug resistance complex (MDR) as key mediators of such metabolism-driven, inflammation-induced process. Indeed, treatment of OC cell lines with TNFα and IL6 induced a selective increase in the expression of TAP1 and multidrug resistance protein 1, whereas TAP1 silencing sensitized cells to cisplatin-induced apoptosis. Our results unveil a novel role for TRAP1 and oxidative metabolism in cancer progression and suggest the targeting of mitochondrial bioenergetics to increase cisplatin efficacy in human OC.Cell Death and Differentiation advance online publication, 20 May 2016; doi:10.1038/cdd.201
Hopkins TG, Blagden S, Mura M, et al., 2016, The RNA-binding protein LARP1 is a post-transcriptional regulator of survival and tumorigenesis in ovarian cancer, Nucleic Acids Research, Vol: 44, Pages: 1227-1246, ISSN: 1362-4962
RNA-binding proteins (RBPs) are increasingly identifiedas post-transcriptional drivers of cancer progression.The RBP LARP1 is an mRNA stability regulator,and elevated expression of the protein in hepatocellularand lung cancers is correlated with adverseprognosis. LARP1 associates with an mRNA interactomethat is enriched for oncogenic transcripts.Here we explore the role of LARP1 in epithelial ovariancancer, a disease characterized by the rapid acquisitionof resistance to chemotherapy through theinduction of pro-survival signalling. We show, usingovarian cell lines and xenografts, that LARP1 is requiredfor cancer cell survival and chemotherapy resistance.LARP1 promotes tumour formation in vivoand maintains cancer stem cell-like populations. Usingtranscriptomic analysis following LARP1 knockdown,cross-referenced against the LARP1 interactome,we identify BCL2 and BIK as LARP1 mRNAtargets. We demonstrate that, through an interactionwith the 3 untranslated regions (3 UTRs) of BCL2and BIK, LARP1 stabilizes BCL2 but destabilizes BIKwith the net effect of resisting apoptosis. Together,our data indicate that by differentially regulating thestability of a selection of mRNAs, LARP1 promotesovarian cancer progression and chemotherapy resistance.
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