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Uveal melanoma is the most common primary intraocular malignancy in adults. Up to 50% of UM patients develop metastatic disease, usually in the liver. When metastatic, the prognosis is poor, and few treatment options exist. Here, we investigated the feasibility of establishing patient-derived xenografts (PDXs) from a patient's tumor in order to screen for therapies that the patient could benefit from. Samples obtained from 29 primary tumors and liver metastases of uveal melanoma were grafted into SCID mice. PDX models were successfully established for 35% of primary patient tumors and 67% of liver metastases. The tumor take rate was proportional to the risk of metastases. PDXs showed the same morphology, the same GNAQ/11, BAP1, and SF3B1 mutations, and the same chromosome 3 and 8q status as the corresponding patient samples. Six PDX models were challenged with two compounds for 4 weeks. We show that, for 31% of patients with high or intermediate risk of metastasis, the timing to obtain efficacy results on PDX models derived from their primary tumors was compatible with the selection of the therapy to treat the patient after relapse. PDXs could thus be a valid tool ("avatar") to select the best personalized therapy for one third of patients that are most at risk of relapse. [ABSTRACT FROM AUTHOR]

Although combined PD-1/CTLA-4 inhibition showed limited efficacy in single-arm, phase II trials in metastatic uveal melanoma (mUM), such combination appears frequently used in mUM patients. We here report our experience with nivolumab/ipilimumab in mUM. A retrospective cohort of 47 mUM patients, 24 men and 23 women, received nivolumab/ipilimumab between October 2019 and December 2021, mostly first line (94%). Two regimens were used: nivolumab 1 mg/kg + ipilimumab 3 mg/kg (nivo1ipi3, 49% of patients) and nivolumab 3 mg/kg + ipilimumab 1 mg/kg (nivo3ipi1, 51% of patients). Median follow-up was 37 and 88 weeks in nivo3ipi1 and nivo1ipi3 cohorts, respectively. We observed partial response in two patients (4%) and stable disease in 14 patients (30%), with no significant difference between the two regimens. Median progression-free survival was 13.6 weeks and 11.9 weeks in the nivo1ipi3 and nivo3ipi1 cohorts, respectively (p = 0.49). Severe adverse events (grade 3 or 4) were observed in seven patients (15%) among which five treated with nivo1ipi3 (22%) and two treated with nivo3ipi1 (8%). These data suggest that nivolumab/ipilimumab combination does not improve clinical outcomes compared to other therapies but is more toxic. In the absence of controlled clinical trials, we would not recommend this combination as a standard treatment in all mUM patients but rather as an option. Patients for whom the benefit-risk ratio could justify the combination need to be defined. [ABSTRACT FROM AUTHOR]

Mammalian cells possess two isoforms of the histone H3-H4 chaperone anti-silencing function 1 (Asf1), Asf1a and Asf1b. However to date, whether they have individual physiological roles has remained elusive. Here, we aim to elucidate the functional importance of Asf1 isoforms concerning both basic and applied aspects. First, we reveal a specific proliferation-dependent expression of human Asf1b unparalleled by Asf1a. Strikingly, in cultured cells, both mRNA and protein corresponding to Asf1b decrease upon cell cycle exit. Depletion of Asf1b severely compromises proliferation, leads to aberrant nuclear structures and a distinct transcriptional signature. Second, a major physiological implication is found in the applied context of tissue samples derived from early stage breast tumours in which we examined Asf1a/b levels. We reveal that overexpression of Asf1b mRNA correlate with clinical data and disease outcome. Together, our results highlight a distribution of tasks between the distinct Asf1 isoforms, which emphasizes a specialized function of Asf1b required for proliferation capacity. We discuss the implications of these results for breast cancer diagnosis and prognosis. [ABSTRACT FROM AUTHOR]

In eukaryotes, DNA is organized into chromatin in a dynamic manner that enables it to be accessed for processes such as transcription and repair. Histones, the chief protein component of chromatin, must be assembled, replaced or exchanged to preserve or change this organization according to cellular needs. Histone chaperones are key actors during histone metabolism. Here we classify known histone chaperones and discuss how they build a network to escort histone proteins. Molecular interactions with histones and their potential specificity or redundancy are also discussed in light of chaperone structural properties. The multiplicity of histone chaperone partners, including histone modifiers, nucleosome remodelers and cell-cycle regulators, is relevant to their coordination with key cellular processes. Given the current interest in chromatin as a source of epigenetic marks, we address the potential contributions of histone chaperones to epigenetic memory and genome stability. [ABSTRACT FROM AUTHOR]

Protein HMGB1 has long been known as one of the most abundant non-histone proteins in the nucleus of mammalian cells, and has regained interest recently for its function as an extracellular cytokine. As a DNA-binding protein, HMGB1 facilitates DNA–protein interactions by increasing the flexibility of the double helix, and binds specifically to distorted DNA structures. We have previously observed that HMGB1 binds with extremely high affinity to a novel DNA structure, hemicatenated DNA loops (hcDNA), in which double-stranded DNA fragments containing a tract of poly(CA)·poly(TG) form a loop maintained at its base by a hemicatenane. Here, we show that the single HMGB1 domains A and B, the HMG-box domain of sex determination factor SRY, as well as the prokaryotic HMGB1-like protein HU, specifically interact with hcDNA (K d∼0.5nM). However, the affinity of full-length HMGB1 for hcDNA is three orders of magnitude higher (K d<0.5pM) and requires the simultaneous presence of both HMG-box domains A and B plus the acidic C-terminal tail on the molecule. Interestingly, the high affinity of the full-length protein for hcDNA does not decrease in the presence of magnesium. Experiments including a comparison of HMGB1 binding to hcDNA and to minicircles containing the CA/TG sequence, binding studies with HMGB1 mutated at intercalating amino acid residues (involved in recognition of distorted DNA structures), and exonuclease III footprinting, strongly suggest that the hemicatenane, not the DNA loop, is the main determinant of the affinity of HMGB1 for hcDNA. Experiments with supercoiled CA/TG-minicircles did not reveal any involvement of left-handed Z-DNA in HMGB1 binding. Our results point to a tight structural fit between HMGB1 and DNA hemicatenanes under physiological conditions, and suggest that one of the nuclear functions of HMGB1 could be linked to the possible presence of hemicatenanes in the cell. [Copyright &y& Elsevier]

Background information: Arpin, an Arp2/3 inhibitory protein, inhibits lamellipodial protrusions and cell migration. Arpin expression is lost in tumor cells of several cancer types. Results: Here we analyzed expression levels of Arpin and various markers using Reverse Phase Protein Array (RPPA) in human mammary carcinomas. We found that Arpin protein levels were correlated with those of several DNA damage response markers. Arpin‐null cells display enhanced clustering of double stand breaks (DSBs) when cells are treated with a DNA damaging agent, in line with a previously described role of the Arp2/3 complex in promoting DSB clustering for homologous DNA repair (HDR) in the nucleus. Using a specific HDR assay, we further showed that Arpin depletion increased HDR efficiency two‐fold through its ability to inactivate the Arp2/3 complex. Conclusions: Arpin regulates both cell migration in the cytosol and HDR in the nucleus. Significance: Loss of Arpin expression coordinates enhanced cell migration with up‐regulated DNA repair, which is required when DNA damage is induced by active cell migration. [ABSTRACT FROM AUTHOR]

Simple Summary: The naturally occurring derivative of estrogen, 2-methoxyestradiol (2-ME), has been shown to have good anti-cancer properties. However, it is broken down too quickly within the blood to be clinically useful. We designed 2-ME analogs with modifications which could avoid rapid metabolism, would preferably stay in the tumor, and were more toxic to cancer cells. Here, we looked more closely at how these compounds work within cancer cells, and how they communicate within themselves and with their environment. ESE-15-one and ESE-16 interfere with the functioning of the intracellular cytoskeleton (actin and microtubules), sending messages that stop cell division, intracellular transport of proteins, and cell migration and invasion, eventually inducing cell suicide. They also inhibited the movement of cells that make blood vessels that would support tumor growth. Using eggs with chicken embryos, we could show that the compounds reduced the tumor size and diminished the spread of cancer cells in a living system. The microtubule-disrupting agent 2-methoxyestradiol (2-ME) displays anti-tumor and anti-angiogenic properties, but its clinical development is halted due to poor pharmacokinetics. We therefore designed two 2-ME analogs in silico—an ESE-15-one and an ESE-16 one—with improved pharmacological properties. We investigated the effects of these compounds on the cytoskeleton in vitro, and their anti-angiogenic and anti-metastatic properties in ovo. Time-lapse fluorescent microscopy revealed that sub-lethal doses of the compounds disrupted microtubule dynamics. Phalloidin fluorescent staining of treated cervical (HeLa), metastatic breast (MDA-MB-231) cancer, and human umbilical vein endothelial cells (HUVECs) displayed thickened, stabilized actin stress fibers after 2 h, which rearranged into a peripheral radial pattern by 24 h. Cofilin phosphorylation and phosphorylated ezrin/radixin/moesin complexes appeared to regulate this actin response. These signaling pathways overlap with anti-angiogenic, extra-cellular communication and adhesion pathways. Sub-lethal concentrations of the compounds retarded both cellular migration and invasion. Anti-angiogenic and extra-cellular matrix signaling was evident with TIMP2 and P-VEGF receptor-2 upregulation. ESE-15-one and ESE-16 exhibited anti-tumor and anti-metastatic properties in vivo, using the chick chorioallantoic membrane assay. In conclusion, the sulfamoylated 2-ME analogs displayed promising anti-tumor, anti-metastatic, and anti-angiogenic properties. Future studies will assess the compounds for myeloproliferative effects, as seen in clinical applications of other drugs in this class. [ABSTRACT FROM AUTHOR]

Despite much progress in our understanding of uveal melanoma (UM) over the past decades, this rare tumour is still often misclassified. Although UM, like other melanomas, is very probably derived from melanocytes, it is drastically different from cutaneous melanoma and most other melanoma subtypes in terms of epidemiology, aetiology, biology and clinical features, including an intriguing metastatic hepatotropism. UM carries distinctive prognostic chromosome alterations, somatic mutations and gene expression profiles, allowing an active tailored surveillance strategy and dedicated adjuvant clinical trials. There is no standard systemic treatment for disseminated UM at present. In contrast to cutaneous melanoma, UMs are not BRAF-mutated, thus curtailing the use of B-Raf inhibitors. Although these tumours are characterised by some immune infiltrates, immune checkpoint inhibitors are rarely effective, possibly due to a low mutation burden. UM patients across the world not only face rare cancer-related issues (e.g., specific management strategies, access to information and to expert centres), but also specific UM problems, which can be exacerbated by the common misconception that it is a subtype of cutaneous melanoma. As a European Consortium dedicated to research on UM and awareness on the disease, "UM Cure 2020" participants urge medical oncologists, pharmaceutical companies, and regulatory agencies to acknowledge UM as a melanoma with specific issues, in order to accelerate the development of new therapies for patients. [ABSTRACT FROM AUTHOR]

Uveal melanoma (UM) remains without effective therapy at the metastatic stage, which is associated with BAP-1 (BRCA1 associated protein) mutations. However, no data on DNA repair capacities in UM are available. Here, we use UM patient-derived xenografts (PDXs) to study the therapeutic activity of the PARP inhibitor olaparib, alone or in combination. First, we show that the expression and the activity of PARP proteins is similar between the PDXs and the corresponding patient's tumors. In vivo experiments in the PDX models showed that olaparib was not efficient alone, but significantly increased the efficacy of dacarbazine. Finally, using reverse phase protein arrays and immunohistochemistry, we identified proteins involved in DNA repair and apoptosis as potential biomarkers predicting response to the combination of olaparib and dacarbazine. We also observed a high increase of phosphorylated YAP and TAZ proteins after dacarbazine + olaparib treatment. Our results suggest that PARP inhibition in combination with the alkylating agent dacarbazine could be of clinical interest for UM treatment. We also observe an interesting effect of dacarbazine on the Hippo pathway, confirming the importance of this pathway in UM. [ABSTRACT FROM AUTHOR]

To better define the role of FOXO1 and FOXO3 transcriptional factors in breast carcinogenesis, we performed a comparative study of their expression at both the RNA and protein levels in a series of human breast tumors. We used qRT-PCR assay to quantify mRNA expression and Reverse Phase Protein Arrays (RPPA) to quantify protein expression in 218 breast tumors from patients with known clinical/pathological status and outcome. Weak correlations were observed between mRNA and protein expressions for both FOXO1 and FOXO3 genes. High expression of FOXO3 protein, but not FOXO1 protein, was a good prognostic marker, negatively correlated with KI67 and markers of activity of the PI3K/AKT/mTOR oncogenic pathway, and positively correlated with p53, a marker of apoptosis. Moreover, FOXO3 protein expression, but not FOXO1 protein expression, was also negatively correlated with various proteins involved in different DNA repair mechanisms. FOXO3 protein, but not FOXO1 protein, appears to be a tumor suppressor that inhibits breast cancer by altering DNA damage response (DDR), thereby inducing p53-dependent apoptosis. This antitumor effect appears to be suppressed by excessive activity of the PI3K/AKT/mTOR pathway. High FOXO3 protein expression could be a biomarker of deficient DDR in breast tumors. [ABSTRACT FROM AUTHOR]

Reverse Phase Protein Arrays (RPPA) were applied for the quantification and validation of protein biomarkers of beef qualities on M. longissimus thoracis sampled early post-mortem from young Charolais bulls. pHu was related to six proteins, three of which are glycolytic enzymes (ENO1, ENO3 and TPI1), while others belong to structural (TTN and α-actin) and proteolytic (μ-calpain) pathways. For color traits, several correlations were found, interestingly with structural proteins. The relationships were in some cases trait-dependent. To understand the mechanisms and explore animal variability, color data were categorized into three classes. α-actin and TTN allowed efficient separation of the classes and were strongly related with all color traits. Biomarkers belonging to heat stress and metabolism pathways were also involved. Two identified proteins, namely Four and a half LIM domains 1 (FHL1) and Tripartite motif-containing 72 (TRIM72), were for the first time related to beef color. Overall, these relationships could be used to develop muscle-specific processing strategies to improve beef color stability. [ABSTRACT FROM AUTHOR]

Background: The immune landscape of uveal melanoma liver metastases (UMLM) has not been sufficiently studied. Methods: Immune cell infiltrates (ICIs), PD-1 and PD-L1 were characterised in 62 UMLM and 28 primary uveal melanomas (PUM). ICI, PD-1 and PD-L1 were scored as: (1) % tumoral area occupied by tumour-infiltrating lymphocytes or macrophages (TILs, TIMs) and (2) % perTumoral (perT) area. ICIs and other variables including histopathologic growth patterns (HGPs), replacement and desmoplastic, of UMLM were analysed for their prognostic value. Results: ICIs recognised by haematoxylin-eosin-saffron (HES) and IHC (e.g., T cells (CD3), B cells (CD20). Macrophages (CD68), (CD163), were primarily localised to the perT region in PUM and UMLM and were more conspicuous in UMLM. HES, CD3, CD4, FoxP3, CD8, CD20, PD-1 TILs were scant (<5%). TIMs were more frequent, particularly in UMLM than in PUM. Both CD68+ TIMs and HGPs remained significant on multivariate analysis, influencing overall (OS) and metastasis-specific overall survival (MSOS). CD68 + , CD163+ and CD20+ perT infiltrates in UMLM predicted increased OS and MSOS on univariate analysis. Conclusions: TILs and PD-L1 have no predictive value in PUM or UMLM. CD68+ and CD163+TIMs, CD20+ perT lymphocytes, and HGPs are important prognostic factors in UMLMs. [ABSTRACT FROM AUTHOR]

Background: Radiotherapy plays a major role in the management of high grade glioma. However, the radioresistance of glioma cells limits its efficiency and drives recurrence inside the irradiated tumor volume leading to poor outcome for patients. Stereotactic hypofractionated radiotherapy is one option for recurrent high grade gliomas. Optimization of hypofractionated radiotherapy with new radiosensitizing agents requires the identification of robust druggable targets involved in radioresistance.Methods: We generated 11 xenografted glioma models: 6 were derived from cell lines (1 WHO grade III and 5 grade IV) and 5 were patient derived xenografts (2 WHO grade III and 3 grade IV). Xenografts were treated by hypofractionated radiotherapy (6x5Gy). We searched for 89 biomarkers of radioresistance (39 total proteins, 26 phosphoproteins and 24 ratios of phosphoproteins on total proteins) using Reverse Phase Protein Array.Results: Both type of xenografted models showed equivalent spectrum of sensitivity and profile of response to hypofractionated radiotherapy. We report that Phospho-EGFR/EGFR, Phospho-Chk1/Chk1 and VCP were associated to resistance to hypofractionated radiotherapy.Conclusions: Several compounds targeting EGFR or CHK1 are already in clinical use and combining them with stereotactic hypofractionated radiotherapy for recurrent high grade gliomas might be of particular interest. [ABSTRACT FROM AUTHOR]

Targeting CSF-1R may revert resistance to PD1inh in uveal melanoma, a report from @institut_curie, @GustaveRoussy, and #OscarLambret @GroupeUnicancer [ABSTRACT FROM AUTHOR]

A correction to the article "Histone chaperones: an escort network regulating histone traffic," that was published in the November 5, 2007 issue is presented.

Background: Medullary thyroid carcinoma (MTC) is a rare tumor that is caused by activating mutations in the proto-oncogene RET. Vandetanib, a tyrosine-kinase inhibitor, has been recently approved to treat adult patients with metastatic MTC. The aim of this study was to investigate changes in signaling pathways induced by vandetanib treatment in preclinical MTC models, using the reverse-phase protein array method (RPPA). Methods: The human TT cell line was used to assess in vitro and in vivo activity of vandetanib. Protein extracts from TT cells or TT xenografted mice, treated by increasing concentrations of vandetanib for different periods of time, were probed with a set of 12 antibodies representing major signaling pathways, using RPPA. Results were validated using two distinct protein detection methods: Western immunoblotting and immunohistochemistry. Results: Vandetanib displays antiproliferative and antiangiogenic activities and inhibits RET autophosphorylation. The MAPK and AKT pathways were the two major signaling pathways inhibited by vandetanib. Interestingly, phosphorylated levels of NFκB-p65 were significantly increased by vandetanib. Comparable results were obtained in both the in vitro and in vivo approaches, as well as for the protein detection methods. However, some discrepancies were observed between RPPA and Western immunoblotting, possibly due to lack of specificity of the primary antibodies used. Conclusions: Overall, our results confirmed the interest of RPPA for screening global changes induced in signaling pathways by kinase inhibitors. MAPK and AKT were identified as the main pathways involved in vandetanib response in MTC models. Our results also suggest alternative routes for controlling the disease, and provide a rationale for the development of therapeutic combinations based on the comprehensive identification of molecular events induced by inhibitors. [ABSTRACT FROM AUTHOR]

Abstract: Hyperhomocysteinemia, characterized by high plasma homocysteine levels, is recognized as an independent risk factor for cardiovascular diseases. The increased synthesis of homocysteine, a product of methionine metabolism involving B vitamins, and its slower intracellular utilization cause increased flux into the blood. Plasma homocysteine level is an important reflection of hepatic methionine metabolism and the rate of processes modified by B vitamins as well as different enzyme activity. Lowering homocysteine might offer therapeutic benefits. However, approximately 50% of hyperhomocysteinemic patients due to cystathionine-beta-synthase deficiency are biochemically responsive to pharmacological doses of B vitamins. Therefore, effective treatments to reduce homocysteine levels are needed, and gene therapy could provide a novel approach. We recently showed that hepatic expression of DYRK1A, a serine/threonine kinase, is negatively correlated with plasma homocysteine levels in cystathionine-beta-synthase deficient mice, a mouse model of hyperhomocysteinemia. Therefore, Dyrk1a is a good candidate for gene therapy to normalize homocysteine levels. We then used an adenoviral construct designed to restrict expression of DYRK1A to hepatocytes, and found decreased plasma homocysteine levels after hepatocyte-specific Dyrk1a gene transfer in hyperhomocysteinemic mice. The elevation of pyridoxal phosphate was consistent with the increase in cystathionine-beta-synthase activity. Commensurate with the decreased plasma homocysteine levels, targeted hepatic expression of DYRK1A resulted in elevated plasma paraoxonase-1 activity and apolipoprotein A-I levels, and rescued the Akt/GSK3 signaling pathways in aorta of mice, which can prevent homocysteine-induced endothelial dysfunction. These results demonstrate that hepatocyte-restricted Dyrk1a gene transfer can offer a useful therapeutic targets for the development of new selective homocysteine lowering therapy. [Copyright &y& Elsevier]

Slug/Snail2 belongs to the Epithelial-Mesenchymal Transition (EMT)-inducing transcription factors involved in development and diseases. Slug is expressed in adult stem/progenitor cells of several epithelia, making it unique among these transcription factors. To investigate Slug role in human bronchial epithelium progenitors, we studied primary bronchial basal/progenitor cells in an air-liquid interface culture system that allows regenerating a bronchial epithelium. To identify Slug downstream genes we knocked down Slug in basal/progenitor cells from normal subjects and subjects with COPD, a respiratory disease presenting anomalies in the bronchial epithelium and high levels of TGF-β in the lungs. We show that normal and COPD bronchial basal/progenitors, even when treated with TGF-β, express both epithelial and mesenchymal markers, and that the epithelial marker E-cadherin is not a target of Slug and, moreover, positively correlates with Slug. We reveal that Slug downstream genes responding to both differentiation and TGF-β are different in normal and COPD progenitors, with in particular a set of proliferation-related genes that are among the genes repressed downstream of Slug in normal but not COPD. In COPD progenitors at the onset of differentiation in presence of TGF-β,we show that there is positive correlations between the effect of differentiation and TGF-β on proliferation-related genes and on Slug protein, and that their expression levels are higher than in normal cells. As well, the expression of Smad3 and β-Catenin, two molecules from TGF-βsignaling pathways, are higher in COPD progenitors, and our results indicate that proliferation-related genes and Slug protein are increased by different TGF-β-induced mechanisms. [ABSTRACT FROM AUTHOR]

Reverse-phase protein array (RPPA) technology uses panels of high-specificity antibodies to measure proteins and protein post-translational modifications in cells and tissues. The approach offers sensitive and precise quantification of large numbers of samples and has thus found applications in the analysis of clinical and pre-clinical samples. For effective integration into drug development and clinical practice, robust assays with consistent results are essential. Leveraging a collaborative RPPA model, we set out to assess the variability between three different RPPA platforms using distinct instrument set-ups and workflows. Employing multiple RPPA-based approaches operated across distinct laboratories, we characterised a range of human breast cancer cells and their protein-level responses to two clinically relevant cancer drugs. We integrated multi-platform RPPA data and used unsupervised learning to identify protein expression and phosphorylation signatures that were not dependent on RPPA platform and analysis workflow. Our findings indicate that proteomic analyses of cancer cell lines using different RPPA platforms can identify concordant profiles of response to pharmacological inhibition, including when using different antibodies to measure the same target antigens. These results highlight the robustness and the reproducibility of RPPA technology and its capacity to identify protein markers of disease or response to therapy. [ABSTRACT FROM AUTHOR]

Highlights • Three signal pathway inhibitors show higher toxicities than cisplatin: verteporfin, defactinib and NSC668394. • Verteporfin sensitivity is related to molecular classification in subgroups. • Verteporfin inhibits cell viability independently of YAP. • Defactinib sensitivity is related to FAK protein kinase activation. • Predictive biomarkers of inhibitors response were defined based on gene expression. Abstract Objectives Malignant pleural mesothelioma (MPM) is an aggressive tumor with limited therapeutic options, requiring the development of efficient targeted therapies based on molecular phenotype of the tumor and to identify predictive biomarkers of the response. Materials and methods The effect of inhibitors was investigated by cell viability assessment on primary MPM cell lines established in our laboratory from patient tumors, well characterized at the molecular level. Effects on apoptosis, cell proliferation and viability on MPM growing in multicellular spheroid were also assessed for verteporfin. Gene and protein expression, and gene knockdown by RNA interference were used to define mechanism of inhibition and specific predictive biomarkers. Results Anti-tumor effect of eight major signaling pathways inhibitors involved in mesothelial carcinogenesis was investigated. Three inhibitors were more efficient than cisplatin, the drug used as first-line chemotherapy in patients with MPM: verteporfin, a putative YAP inhibitor, defactinib, a FAK inhibitor and NSC668394, an Ezrin inhibitor. Verteporfin, the most efficient inhibitor, induced cell proliferation arrest and cell death, and is effective on 3D spheroid multicellular model. Verteporfin sensitivity was YAP-independent and related to molecular classification of the tumors. Biomarkers based on gene expression were identified to predict accurately sensitivity to these three inhibitors. Conclusion Our study shows that drug screening on well-characterized MPM cells allows for the identification of novel potential therapeutic strategies and defining specific biomarkers predictive of the drug response. [ABSTRACT FROM AUTHOR]

The validation of biomarkers and tools for the prediction of beef texture remains a challenging task. In this study, reverse phase protein arrays (RPPA) quantified 29 protein biomarkers in the m. Longissimus thoracis of Charolais cattle sampled early post-mortem . Myosin heavy chain 1 (MHC1, slow-oxidative fibers) and Retinal dehydrogenase 1 (ALDH1A1, oxidative enzyme) discriminated between tender and juicy vs. tough meat with residues classes and are validated as prime biomarkers of beef texture. Several proteins belonging to energy metabolism, heat shock and oxidative stress, cytoskeletal, cell signaling and apoptosis were related with tenderness. Among the unusual proteins, Four and a half LIM domains 1 (FHL1) and Tripartite motif protein 72 (TRIM72) correlated respectively negatively and positively with beef tenderness. Principal component regression was used for the first time to explain beef texture traits using biomarkers. The results are very promising as they revealed sophisticated mechanisms behind the tenderizing process. [ABSTRACT FROM AUTHOR]

Background: Metastatic colorectal cancer (mCRC) patients with mutant KRAS or NRAS are ineligible for anti-epidermal growth factor receptor (anti-EGFR) therapy, as RAS mutations activate downstream pathways independently of EGFR and induce primary resistance. However, even among RAS wild-type (WT) patients, only a fraction responds to anti-EGFR therapy, suggesting that other mechanisms of resistance exist. We hypothesise that different (epi)genetic alterations can lead to primary anti-EGFR resistance and that the crucial end point is the activation of protein signalling pathways.Methods: We analysed the expression and activation of proteins involved in cell signalling, using reverse phase protein arrays, on a multicentre French cohort of RAS WT mCRC treated with anti-EGFR treatment.Results: We identify activated EGFR and HER3 as protein biomarkers predictive for better overall survival. Active EGFR signalling and downstream PI3K, but not MAPK, pathway activation are associated with response to anti-EGFR treatment. Left-sided mCRC displays active ErbB2/3 and Wnt pathways and a better response to anti-EGFR therapy compared to right-sided mCRC.Conclusions: We identify active EGFR and PI3K signalling as a key factor for response to anti-EGFR treatment in mCRC and highlight the importance of developing these biomarkers in clinical practice for the selection of RAS WT mCRC patients that would benefit from anti-EGFR treatment. [ABSTRACT FROM AUTHOR]

High intensity training (HIT) has been shown to improve maximal aerobic capacity and muscle protein synthesis but has not yet been investigated in senescent rats. We hypothesized that the change of speed (acceleration) during each bout of HIT acts as a stimulus responsible for the adaptations of the organism to exercise. Twenty two month-old (mo) rats ( n = 13) were subjected to a short acceleration protocol (20–30 min) of exercise, comprising 3 independent bouts of acceleration and compared to an age-matched sedentary group ( n = 14). The protocol was repeated twice a week for two months. Following the protocol, performance, cardiac function, muscle mechanics, and the cellular and molecular pathways that are implicated in exercise adaptations were investigated. This new training, comprising only 16 sessions, improved maximal oxygen uptake (⩒ O 2peak ; + 6.6%, p < 0.05), running distance (+ 95.2%; p < 0.001), speed (+ 29.7%; p < 0.01) and muscle function of 24 mo rats in only 8 weeks. This new training protocol induced cardiac hypertrophy and improved fractional shortening (47.3% vs. 41.1% in the control group, p < 0.01) and ejection fraction. Moreover, it also improved the mechanics of skeletal muscle by increasing developed force (+ 31% vs. the control group, p < 0.05) and maximal mechanical efficiency, activated the IGF1/mTOR/Akt pathway, and reduced the Smad2/3 pathway. Our results clearly show that the change in speed is a stimulus to control cardiac and skeletal muscle mass. This acceleration-based training is not time-consuming and may be adaptable for athletes, the elderly or chronic disease patients in order to improve strength, oxidative capacity, and quality of life. [ABSTRACT FROM AUTHOR]

Background: Cervical cancer (CC) remains a leading cause of gynaecological cancer-related mortality worldwide. CC pathogenesis is triggered when human papillomavirus (HPV) inserts into the genome, resulting in tumour suppressor gene inactivation and oncogene activation. Collecting tumour and blood samples is critical for identifying these genetic alterations.Methods: BIO-RAIDs is the first prospective molecular profiling clinical study to include a substantial biobanking effort that used uniform high-quality standards and control of samples. In this European Union (EU)-funded study, we identified the challenges that were impeding the effective implementation of such a systematic and comprehensive biobanking effort.Results: The challenges included a lack of uniform international legal and ethical standards, complexities in clinical and molecular data management, and difficulties in determining the best technical platforms and data analysis techniques. Some difficulties were encountered by all investigators, while others affected only certain institutions, regions, or countries.Conclusions: The results of the BIO-RAIDs programme highlight the need to facilitate and standardise regulatory procedures, and we feel that there is also a need for international working groups that make recommendations to regulatory bodies, governmental funding agencies, and academic institutions to achieve a proficient biobanking programme throughout EU countries. This represents the first step in precision medicine. [ABSTRACT FROM AUTHOR]

Background: Epigenetic deregulation is considered as a new hallmark of cancer. The long non-coding RNA MALAT1 has been implicated in several cancers; however, its role in breast cancer is still little known.Methods: We used RT-PCR, in situ hybridisation, and RPPA methods to quantify (i) the full-length (FL) and an alternatively spliced variant (Δsv) of MALAT1, and (ii) a panel of transcripts and proteins involved in MALAT1 pathways, in a large series of breast tumours from patients with known clinical/pathological status and long-term outcome.Results: MALAT1 was overexpressed in 14% (63/446) of the breast tumours. MALAT1-overexpressed tumour epithelial cells showed marked diffuse nuclear signals and numerous huge nuclear speckles. Screening of the dbEST database led to the identification of Δsv-MALAT1, a major alternatively spliced MALAT1 transcript, with a very different expression pattern compared with FL-MALAT1. This alternative Δsv-MALAT1 transcript was mainly underexpressed (18.8%) in our breast tumour series. Multivariate analysis showed that alternative Δsv-MALAT1 transcript is an independent prognostic factor. Δsv-MALAT1 expression was associated with alterations of the pre-mRNAs alternative splicing machinery, and of the Drosha-DGCR8 complex required for non-coding RNA biogenesis. Alternative Δsv-MALAT1 transcript expression was associated to YAP protein status and with an activation of the PI3K-AKT pathway.Conclusions: Our results reveal a complex expression pattern of various MALAT1 transcript variants in breast tumours, and suggest that this pattern of expressions should be taken into account to evaluate MALAT1 as predictive biomarker and therapeutic target. [ABSTRACT FROM AUTHOR]

Background: The Arp2/3 complex is required for cell migration and invasion. The Arp2/3 complex and its activators, such as the WAVE complex, are deregulated in diverse cancers. Here we investigate the expression of Arpin, the Arp2/3 inhibitory protein that antagonises the WAVE complex.Methods: We used qRT-PCR and reverse phase protein arrays in a patient cohort with known clinical parameters and outcome, immunofluorescence in breast biopsy cryosections and breast cancer cell lines.Results: Arpin was downregulated at the mRNA and protein levels in mammary carcinoma cells. Arpin mRNA downregulation was associated with poor metastasis-free survival (MFS) on univariate analysis (P=0.022). High expression of the NCKAP1 gene that encodes a WAVE complex subunit was also associated with poor MFS on univariate analysis (P=0.0037) and was mutually exclusive with Arpin low. Arpin low or NCKAP1 high was an independent prognosis factor on multivariate analysis (P=0.0012) and was strongly associated with poor MFS (P=0.000064).Conclusions: Loss of the Arp2/3 inhibitory protein Arpin produces a similar poor outcome in breast cancer as high expression of the NCKAP1 subunit of the Arp2/3 activatory WAVE complex. [ABSTRACT FROM AUTHOR]

The Hippo signaling network is a key regulator of cell fate. In the recent years, it was shown that its implication in cancer goes well beyond the sole role of YAP transcriptional activity and its regulation by the canonical MST/LATS kinase cascade. Here we show that the motin family member AMOTL1 is an important effector of Hippo signaling in breast cancer.AMOTL1connectsHippo signaling to tumor cell aggressiveness. We show that both canonical and noncanonical Hippo signaling modulates AMOTL1 levels. The tumor suppressor Merlin triggers AMOTL1 proteasomal degradation mediated by the NEDD family of ubiquitin ligases through direct interaction. In parallel, YAP stimulates AMOTL1 expression. The loss of Merlin expression and the induction of Yap activity that are frequently observed in breast cancers thus result in elevated AMOTL1 levels. AMOTL1 expression is sufficient to trigger tumor cell migration and stimulates proliferation by activating c-Src. In a large cohort of human breast tumors, we show that AMOTL1 protein levels are upregulated during cancer progression and that, importantly, the expression of AMOTL1 in lymph node metastasis appears predictive of the risk of relapse. Hence we uncover an important mechanism by which Hippo signaling promotes breast cancer progression by modulating the expression of AMOTL1. [ABSTRACT FROM AUTHOR]

Triple-negative breast cancer (TNBC) represents a subgroup of breast cancers (BC) associated with the most aggressive clinical behavior. No targeted therapy is currently available for the treatment of patients with TNBC. In order to discover potential therapeutic targets, we searched for protein kinases that are overexpressed in human TNBC biopsies and whose silencing in TNBC cell lines causes cell death. A cohort including human BC biopsies obtained at Institut Curie as well as normal tissues has been analyzed at a gene-expression level. The data revealed that the human protein kinase monopolar spindle 1 (hMPS1), also known as TTK and involved in mitotic checkpoint, is specifically overexpressed in TNBC, compared to the other BC subgroups and healthy tissues. We confirmed by immunohistochemistry and reverse phase protein array that TNBC expressed higher levels of TTK protein compared to the other BC subgroups. We then determined the biological effects of TTK depletion by RNA interference, through analyses of tumorigenic capacity and cell viability in different human TNBC cell lines. We found that RNAi-mediated depletion of TTK in various TNBC cell lines severely compromised their viability and their ability to form colonies in an anchorage-independent manner. Moreover, we observed that TTK silencing led to an increase in H2AX phosphorylation, activation of caspases 3/7, sub-G1 cell population accumulation and high annexin V staining, as well as to a decrease in G1 phase cell population and an increased aneuploidy. Altogether, these data indicate that TTK depletion in TNBC cells induces apoptosis. These results point out TTK as a protein kinase overexpressed in TNBC that may represent an attractive therapeutic target specifically for this poor prognosis associated subgroup of breast cancer. [ABSTRACT FROM AUTHOR]

Breast cancers are composed of molecularly distinct subtypes with different clinical outcomes and responses to therapy. To discover potential therapeutic targets for the poor prognosis-associated triple-negative breast cancer (TNBC), gene expression profiling was carried out on a cohort of 130 breast cancer samples. Polo-like kinase 1 (PLK1) was found to be significantly overexpressed in TNBC compared with the other breast cancer subtypes. High PLK1 expression was confirmed by reverse phase protein and tissue microarrays. In triple-negative cell lines, RNAi-mediated PLK1 depletion or inhibition of PLK1 activity with a small molecule (BI-2536) induced an increase in phosphorylated H2AX, G2--M arrest, and apoptosis. A soft-agar colony assay showed that PLK1 silencing impaired clonogenic potential of TNBC cell lines. When cells were grown in extracellular matrix gels (Matrigel), and exposed to BI-2536, apoptosiswas observed specifically in TNBC cancerous cells, and not in a normal cell line. When administrated as a single agent, the PLK1 inhibitor significantly impaired tumor growth in in vivo two xenografts models established from biopsies of patients with TNBC. Most importantly, the administration of BI-2536, in combination with doxorubicin + cyclophosphamide chemotherapy, led to a faster complete response compared with the chemotherapy treatment alone and prevented relapse, which is the major risk associated with TNBC. Altogether, our observations suggest PLK1 inhibition as an attractive therapeutic approach, in association with conventional chemotherapy, for the management of patients with TNBC. [ABSTRACT FROM AUTHOR]

Motivation: Reverse phase protein array (RPPA) is a powerful dot-blot technology that allows studying protein expression levels as well as post-translational modifications in a large number of samples simultaneously. Yet, correct interpretation of RPPA data has remained a major challenge for its broad-scale application and its translation into clinical research. Satisfying quantification tools are available to assess a relative protein expression level from a serial dilution curve. However, appropriate tools allowing the normalization of the data for external sources of variation are currently missing. Results: Here we propose a new method, called NormaCurve, that allows simultaneous quantification and normalization of RPPA data. For this, we modified the quantification method SuperCurve in order to include normalization for (i) background fluorescence, (ii) variation in the total amount of spotted protein and (iii) spatial bias on the arrays. Using a spike-in design with a purified protein, we test the capacity of different models to properly estimate normalized relative expression levels. The best performing model, NormaCurve, takes into account a negative control array without primary antibody, an array stained with a total protein stain and spatial covariates. We show that this normalization is reproducible and we discuss the number of serial dilutions and the number of replicates that are required to obtain robust data. We thus provide a ready-touse method for reliable and reproducible normalization of RPPA data, which should facilitate the interpretation and the development of this promising technology. [ABSTRACT FROM AUTHOR]

DNA damage triggers a complex signaling cascade involving a multitude of phosphorylation events. We found that the threonine 7 (Thr-7) residue of heat shock protein 90α (Hsp90α) was phosphorylated immediately after DNA damage. The phosphorylated Hsp90α then accumulated at sites of DNA double strand breaks and formed repair foci with slow kinetics, matching the repair kinetics of complex DNA damage. The phosphorylation of Hsp90α was dependent on phosphatidylinositol 3-kinase-like kinases, including the DNA-dependent protein kinase (DNA-PK) in particular. DNA-PK plays an essential role in the repair of DNA double strand breaks by nonhomologous end-joining and in the signaling of DNA damage. It is also present in the cytoplasm of the cell and has been suggested to play a role in cytoplasmic signaling pathways. Using stabilized double-stranded DNA molecules to activate DNA-PK, we showed that an active DNA-PK complex could be assembled in the cytoplasm, resulting in phosphorylation of the cytoplasmic pool of Hsp90α. In vivo, reverse phase protein array data for tumors revealed that basal levels of Thr-7-phosphorylated Hsp90α were correlated with phosphorylated histone H2AX levels. The Thr-7 phosphorylation of the ubiquitously produced and secreted Hsp90α may therefore serve as a surrogate biomarker of DNA damage. These findings shed light on the interplay between central DNA repair enzymes and an essential molecular chaperone. [ABSTRACT FROM AUTHOR]

Simple Summary: For clinicians, rapid diagnosis of early neoplastic lesions and prediction of treatment response are two key aspects to guide their choice of treatment. Current histological markers are based on proliferation, differentiation states or specific cell function, but do not take full advantage of tumor characteristics. We show that the subnuclear distribution of CENP-A, the centromeric histone variant, provides, for both aspects, information distinct from and independent of commonly used markers. Our study reveals that in locally advanced head and neck squamous cell cancer patients, the subnuclear distribution of CENP-A at the time of diagnosis is an independent predictive marker of local disease control and curability by concurrent chemoradiation therapy. We provide evidence for the clinical applicability of this CENP-A labeling as a cost-effective marker regardless of genetic alterations in the tumor, perfectly compatible with the clinical time constraints in the course of therapy. Effective biomarkers predictive of the response to treatments are key for precision medicine. This study identifies the staining pattern of the centromeric histone 3 variant, CENP-A, as a predictive biomarker of locoregional disease curability by chemoradiation therapy. We compared by imaging the subnuclear distribution of CENP-A in normal and tumoral tissues, and in a retrospective study in biopsies of 62 locally advanced head and neck squamous cell carcinoma (HNSCC) patients treated by chemoradiation therapy. We looked for predictive factors of locoregional disease control and patient's survival, including CENP-A patterns, Ki67, HPV status and anisokaryosis. In different normal tissues, we reproducibly found a CENP-A subnuclear pattern characterized by CENP-A clusters both localized at the nuclear periphery and regularly spaced. In corresponding tumors, both features are lost. In locally advanced HNSCC, a specific CENP-A pattern identified in pretreatment biopsies predicts definitive locoregional disease control after chemoradiation treatment in 96% (24/25) of patients (OR = 17.6 CI 95% [2.6; 362.8], p = 0.002), independently of anisokaryosis, Ki67 labeling or HPV status. The characteristics of the subnuclear pattern of CENP-A in cell nuclei revealed by immunohistochemistry could provide an easy to use a reliable marker of disease curability by chemoradiation therapy in locally advanced HNSCC patients. [ABSTRACT FROM AUTHOR]

Simple Summary: Melanin content in uveal melanoma is suspected to influence tumoral microenvironment and antitumoral response and is related to higher risk of metastasis and death in the primary disease. However, the prognostic impact of melanin content in liver metastases of uveal melanoma (LMUM) remains unexplored. The aim of our retrospective study was to evaluate the prognostic implications of melanin quantification assessed by MRI with clinical, pathological, and genetic features of LMUM. We found in a population of 63 patients eligible for margin-free resection of LMUM that MRI melanin quantification was an independent prognostic factor associated with overall survival. Liver metastases with high MRI melanin content and high genetic risk "M3/8g" were associated with lower overall survival compared with that of liver metastases with low MRI melanin content and/or low/intermediate genetic risk. The level of pigmentation in "M3/8g" LMUM identified two subsets that were correlated with distinct clinical outcomes. To evaluate the prognostic implications of melanin quantification assessed by magnetic resonance imaging (MRI) with respect to the clinical, pathological, and genetic features of liver metastases of uveal melanoma (LMUM). This single-center retrospective cohort study included 63 patients eligible for margin-free resection of LMUM between 2007 and 2018. Comparative genomic hybridization of resected liver metastases on microarrays was performed for genetic risk classification. Metastases exhibiting monosomy 3 with any type of gain of chromosome 8 (M3/8g) were considered high-genetic-risk. MRI melanin quantification using the mean T1 signal (mT1s) in liver metastases was assessed quantitatively on preoperative imaging examination and compared to that of gross pathological evaluation. The association between MRI melanin quantification and overall survival (OS) was assessed by multivariate analysis using the Cox proportional hazards model. Gross pathological assessment of melanin content and MRI melanin quantification were strongly correlated (r = 0.8, p < 0.001). Independent prognostic factors associated with OS were disease-free interval ≤ 24 months (HR = 3.1; 95% CI, 1.6–6.0; p < 0.001), high-genetic-risk (HR = 2.2; 95% CI, 1.1–4.8; p = 0.04), mT1s > 1.1 (HR = 2.3; 95% CI, 1.2–4.7; p = 0.019), and complete hepatic resection (HR = 0.3; 95% CI, 0.2–0.7; p = 0.004). In patients with high-genetic-risk, mT1s showed a significant association with OS (HR = 3.7; 95% CI, 1.5–9.3; p = 0.006). The median OS was 17.5 months vs. 27 months for >1.1 and ≤1.1 mT1s tumors, respectively (p = 0.003). We showed that the level of pigmentation in M3/8g LMUM identified two subsets that were correlated with distinct clinical outcomes. [ABSTRACT FROM AUTHOR]

The search for novel anti-cancer compounds which can circumvent chemotherapeutic drug resistance and limit systemic toxicity remains a priority. 2-Ethyl-3-O-sulphamoyl-estra-1,3,5(10)15-tetraene-3-ol-17one (ESE-15-one) and 2-ethyl-3-O-sulphamoyl-estra-1,3,5(10)16-tetraene (ESE-16) are sulphamoylated 2-methoxyestradiol (2-ME) analogues designed by our research team. Although their cytotoxicity has been demonstrated in vitro, the temporal and mechanistic responses of the initiated intracellular events are yet to be determined. In order to do so, assays investigating the compounds' effects on microtubules, cell cycle progression, signalling cascades, autophagy and apoptosis were conducted using HeLa cervical- and MDA-MB-231 metastatic breast cancer cells. Both compounds reversibly disrupted microtubule dynamics as an early event by binding to the microtubule colchicine site, which blocked progression through the cell cycle at the G1/S- and G2/M transitions. This was supported by increased pRB and p27Kip1 phosphorylation. Induction of apoptosis with time-dependent signalling involving the p-JNK, Erk1/2 and Akt/mTOR pathways and loss of mitochondrial membrane potential was demonstrated. Inhibition of autophagy attenuated the apoptotic response. In conclusion, the 2-ME analogues induced a time-dependent cross-talk between cell cycle checkpoints, apoptotic signalling and autophagic processes, with an increased reactive oxygen species formation and perturbated microtubule functioning appearing to connect the processes. Subtle differences in the responses were observed between the two compounds and the different cell lines. [ABSTRACT FROM AUTHOR]

• Absolute and relative quantification assays of bovine meat quality protein markers. • MDH1, MYH1, TPI1, ALDH1A1 and CRYAB qualified as biomarkers of meat marbling in bovine. • HSPB1, TNNT1, MDH1, ENO3 and PRDX6 qualified as biomarkers of meat tenderness in bovine. • MYH1, TPI1, ALDH1A1 or CRYAB abundance explains high part of marbling variability. • TNNT1, MDH1, PRDX6 or ENO3 abundance explains high part of shear force variability. We and others have identified biomarker candidates of tenderness or marbling, two major attributes of bovine meat-eating qualities for consumers' satisfaction. In this study, Reverse Phase Protein Arrays (RPPA) and targeted mass spectrometry assays using Parallel Reaction Monitoring (PRM) were developed to test whether 10 proteins pass the sequential qualification and verification steps of the challenging biomarker discovery pipeline. At least MYH1, TPI1, ALDH1A1 and CRYAB were qualified by RPPA or PRM as being differentially abundant according to marbling values of longissimus thoracis and semimembranosus muscles. Significant mathematical relationships between the individual abundance of each of the four proteins and marbling values were verified by linear or logistic regressions. Four proteins, TNNT1, MDH1, PRDX6 and ENO3 were qualified and verified for tenderness, and the abundance of MDH1 explained 49% of the tenderness variability. The present PRM and RPPA results pave the way for development of useful meat industrial multiplex-proteins assays. [ABSTRACT FROM AUTHOR]

In up to 30% of non-small cell lung cancer (NSCLC) patients, the oncogenic driver of tumor growth is a constitutively activated epidermal growth factor receptor (EGFR). Although these patients gain great benefit from treatment with EGFR tyrosine kinase inhibitors, the development of resistance is inevitable. To model the emergence of drug resistance, an EGFR-driven, patient-derived xenograft (PDX) NSCLC model was treated continuously with Gefitinib in vivo. Over a period of more than three months, three separate clones developed and were subsequently analyzed: Whole exome sequencing and reverse phase protein arrays (RPPAs) were performed to identify the mechanism of resistance. In total, 13 genes were identified, which were mutated in all three resistant lines. Amongst them the mutations in NOMO2, ARHGEF5 and SMTNL2 were predicted as deleterious. The 53 mutated genes specific for at least two of the resistant lines were mainly involved in cell cycle activities or the Fanconi anemia pathway. On a protein level, total EGFR, total Axl, phospho-NFκB, and phospho-Stat1 were upregulated. Stat1, Stat3, MEK1/2, and NFκB displayed enhanced activation in the resistant clones determined by the phosphorylated vs. total protein ratio. In summary, we developed an NSCLC PDX line modelling possible escape mechanism under EGFR treatment. We identified three genes that have not been described before to be involved in an acquired EGFR resistance. Further functional studies are needed to decipher the underlying pathway regulation. [ABSTRACT FROM AUTHOR]

Supplementary Table 1 and the Supplementary Figure legends were not included when this manuscript was first published. The files are now available here. [ABSTRACT FROM AUTHOR]

Background: The insulin growth factor (IGF) pathway has been proposed as a potential therapeutic target in bladder cancer. We characterized the expression of components of the IGF pathway - insulin growth factor receptors (INSR, IGF1R, IGF2R), ligands (INS, IGF1, IGF2), and binding proteins (IGFBP1-7, IGF2BP1-3) - in bladder cancer and its correlation with IGF1R activation, and the anti-proliferative efficacy of an IGF1R kinase inhibitor in this setting.Methods: We analyzed transcriptomic data from two independent bladder cancer datasets, corresponding to 200 tumoral and five normal urothelium samples. We evaluated the activation status of the IGF pathway in bladder tumors, by assessing IGF1R phosphorylation and evaluating its correlation with mRNA levels for IGF pathway components. We finally evaluated the correlation between inhibition of proliferation by a selective inhibitor of the IGF1R kinase (AEW541), reported in 13 bladder cancer derived cell lines by the Cancer Cell Line Encyclopedia Consortium and mRNA levels for IGF pathway components.Results: IGF1R expression and activation were stronger in non-muscle-invasive than in muscle-invasive bladder tumors. There was a significant inverse correlation between IGF1R phosphorylation and IGFBP5 expression in tumors. Consistent with this finding, the inhibition of bladder cell line viability by IGF1R inhibitor was also inversely correlated with IGFBP5 expression.Conclusion: The IGF pathway is activated and therefore a potential therapeutic target for non muscle-invasive bladder tumors and IGFBP5 could be used as a surrogate marker for predicting tumor sensitivity to anti-IGF therapy. [ABSTRACT FROM AUTHOR]