PICU Admission of Children for Status Epilepticus: Is There a Different Approach Between Referral and Second-Level Hospitals in an Italian Region?

Appropriate status epilepticus (SE) management is key to minimize admission to the pediatric intensive care unit (PICU). We retrospectively describe 115 children admitted to the PICU of the tertiary-care referral hospital of Padova for seizures, SE, and SE-related complications (59% from second-level hospitals, 41% from the referral hospital) and compare SE management among hospitals. Compared with the referral center, in second-level hospitals, anesthetics were more often administered as first/second drug (P < .001), and intubation was more frequent (P < .001). Intubation was significantly associated with SE onset at home (P = .045) and benzodiazepine-associated respiratory depression (P = .044). There was no association between intubation and SE duration, etiology, PICU length of stay, and morbidity at discharge. In conclusion, adherence to treatment protocols on SE management after the first-line drug differs between referral center and second-level hospitals. Lack of association with SE characteristics and patient's outcome suggests PICU admission could be due to inappropriate invasive management.

A novel auxin-inducible degron system for rapid, cell cycle-specific targeted proteolysis

The discrimination of protein biological functions in different phases of the cell cycle is limited by the lack of experimental approaches that do not require pre-treatment with compounds affecting the cell cycle progression. Therefore, potential cycle-specific biological functions of a protein of interest could be biased by the effects of cell treatments. The OsTIR1/auxin-inducible degron (AID) system allows "on demand" selective and reversible protein degradation upon exposure to the phytohormone auxin. In the current format, this technology does not allow to study the effect of acute protein depletion selectively in one phase of the cell cycle, as auxin similarly affects all the treated cells irrespectively of their proliferation status. Therefore, the AID system requires coupling with cell synchronization techniques, which can alter the basal biological status of the studied cell population, as with previously available approaches. Here, we introduce a new AID system to Regulate OsTIR1 Levels based on the Cell Cycle Status (ROLECCS system), which induces proteolysis of both exogenously transfected and endogenous gene-edited targets in specific phases of the cell cycle. We validated the ROLECCS technology by down regulating the protein levels of TP53, one of the most studied tumor suppressor genes, with a widely known role in cell cycle progression. By using our novel tool, we observed that TP53 degradation is associated with increased number of micronuclei, and this phenotype is specifically achieved when TP53 is lost in S/G2/M phases of the cell cycle, but not in G1. Therefore, we propose the use of the ROLECCS system as a new improved way of studying the differential roles that target proteins may have in specific phases of the cell cycle.

Apneas requiring respiratory support in young infants with COVID-19: a case series and literature review

The objective of this study is to describe the clinical features of young infants with apneas as a clinical sign of COVID-19. We reported the cases of 4 infants who needed respiratory support in our PICU for a severe course of COVID-19 complicated with recurrent apneas. Moreover, we conducted a review of the literature about COVID-19 and apneas in infants ≤ 2 months of corrected age. A total of 17 young infants were included. Overall, in most of the cases (88%), apnea was an initial symptom of COVID-19, and in two cases, it recurred after 3-4 weeks. Regarding neurological workup, most children underwent a cranial ultrasound, while a minority underwent electroencephalography registration, neuroimaging, and lumbar punctures. One child showed signs of encephalopathy on electroencephalogram, with further neurological workup resulting normal. SARS-CoV-2 was never found in the cerebrospinal fluid. Ten children required intensive care unit admission, with five of them needing intubation and three non-invasive ventilation. A less invasive respiratory support was sufficient for the remaining children. Eight children were treated with caffeine. All patients had a complete recovery.  Conclusion: Young infants with recurrent apneas during COVID-19 usually need respiratory support and undergo a wide clinical work-up. They usually show complete recovery even when admitted to the intensive care unit. Further studies are needed to better define diagnostic and therapeutic strategies for these patients. What is Known: • Although the course of COVID-19 in infants is usually mild, some of them may develop a more severe disease needing intensive care support. Apneas may be a clinical sign in COVID-19. What is New: • Infants with apneas during COVID-19 may require intensive care support, but they usually show a benign course of the disease and full recovery.

Is ketamine infusion effective and safe as an adjuvant of sedation in the PICU? Results from the Ketamine Infusion Sedation Study (KISS)

STUDY OBJECTIVE

We aimed to evaluate the efficacy and safety of ketamine in ensuring comfort and sparing conventional drugs when used as an adjuvant for analgesia and sedation in the Pediatric Intensive Care Unit (PICU) as a continuous infusion (≥12 h).

DESIGN

Observational prospective study.

SETTING

Tertiary-care-center PICU.

PATIENTS

All consecutive patients <18 years who received ketamine for ≥12 h between January 2019 and July 2021.

INTERVENTIONS

ketamine infusion for ≥12 h.

MEASUREMENTS AND MAIN RESULTS

Seventy-seven patients (median age 16 months, Interquartile Range (IQR) 7-43) were enrolled. Twenty-six percent of patients (n = 20) were paralyzed, while 74% (n = 57) were not. The median infusion duration was 90 h (IQR 39-193), with doses between 15 (IQR 15-20) and 30 μg/kg/min (IQR 20-50). At 24 h of ketamine infusion, values of COMFORT-B-Scale (CBS) were significantly lower compared with values pre-ketamine (p < 0.001). Simultaneously, doses/kg/h of opioids and benzodiazepines significantly decreased at 24 h (p < 0.001 and p = 0.002, respectively), while doses/kg/h of propofol (p = 0.500) and dexmedetomidine (p = 0.072) did not significantly change. Seventy-four percent of non-paralyzed patients (42/57) had a decrease in CBS ≥2 points with no increase of concomitant analgosedation drugs. Among paralyzed patients (n = 20), 13 (65%) had no increase of concomitant analgosedation within 24 h after ketamine initiation. Overall, 55/77 (71%) of patients responded to ketamine. The mean and maximum ketamine infusion dosages were significantly higher in the non-responders (p = 0.021 and 0.028, respectively). Eleven patients had adverse events potentially related to ketamine (hypersalivation, systemic hypertension, dystonia/dyskinesia, tachycardia, and agitation) and six patients required intervention (dose reduction, suspension, or pharmacologic therapy). None of the patients developed delirium during ketamine infusion.

CONCLUSIONS

Ketamine used as a continuous infusion in the PICU might represent a valid strategy to ensure comfort and spare opioids and benzodiazepines in difficult-to-sedate PICU patients. Adverse events are minor and easily reversible. Future study will be needed to investigate long-term outcomes.

Potential association between working memory and physical fitness status: the BRAVE study

Introduction

The World Health Organization launched a global action plan targeted to obtain a 15% relative reduction in the global prevalence of physical inactivity in adolescents by 2030 also promoting school-based PA interventions and programs in school. Active Breaks (ABs) are a school-based intervention consisting of short bursts (5-15 minutes) of Pa led by teachers or peer. Many researches investigated the implementation of ABs into primary school setting as a strategy to reduce sedentary behaviour, improve cognitive and physical function. However, this kind of intervention has not extended to secondary school, especially in Italian context. For this reason we started the BRAVE study to evaluate the potential effect of implementing ABs in secondary school. The study is currently in the administration phase of ABs to adolescents The preliminary analysis aims to underline a potential association between working memory performance (WM) and physical fitness status among secondary school students at baseline.

Methods

In March 2022 we conducted baseline assessment in a secondary school in Valsamoggia (Bologna, Italy). Working memory was evaluated using backward digit span while physical fitness status was assessed using three different fitness test: standing long-jump (SLJ), six minute Cooper Test (6MCT) and Shuttle run test (SR).

Results

A total of n = 125 adolescent, mean age 12.79±0.89, were enrolled in the study. After performing a regression analysis we found that WM is significantly associated only with age of student (b = 0.2, 95%CI 0.25, 0.11 p = 0.02). A trend also emerged between WM performance and SLJ but with no statistically significant differences (b = 0.160, 95%CI 0.03, 0.02, p = 0.09). The 6MCT and HT have no relevant associations with WM score.

Conclusions

These preliminary results suggest that age is associated with cognitive performance but no positive association were found between WM score and physical fitness status excepted for a small trend with SLJ test.

Key messages

• Age is related to WM in adolescent students.

• ABs interventions could represent a valid strategy to encourage movement, improve cognitive and physical fitness performance.

The effect of active breaks on cognitive performance and classroom behaviour: the I-move study

Background

Active Breaks (ABs) intervention involves short bouts of moderate to vigorous physical activity (MVPA) conducted during or between curricular lessons by the appropriately trained teachers. The aim of the Imola Active Breaks Study (I-MOVE study) was to evaluate the effect of an ABs intervention on cognitive function and classroom behaviour in primary school children.

Methods

The study was quasi-experimental, and it involved two groups attending a primary school in Imola (Bologna, Italy). The Active Breaks group (ABsG) performed the I-MOVE protocol consisting in 10 minutes of ABs divided in warm up, tone-up with high intensity interval training and cool-down. This is repeated three times a day for one year and half. The control group (CG) continued with regular lessons. The baseline assessment was conducted in October 2019 and the follow-up in May 2021. Cognitive performance was assessed using working memory test and classroom behaviour was monitored using an “ad hoc questionnaire”.

Results

Working memory performance increased significantly more in the ABsG (change: 1.30±1.17) than in CG (0.96±1.20), p &lt; 0.05. Almost the entire sample of the children wanted to continue with this intervention in the next following year. Children reported improvements in their school-life quality, including feeling better in class (75.40%) and in school (82.50%) when using ABs. Improvements were also reported in children time-on-task behaviours: 52.90% said they work easily in class, 52.90% that they could listen more clearly, 58.80% reported they can stay seated easily, and 59.60% that they learned better and were more focused after ABs.

Conclusions

In conclusion the program has proven to be very effective on the children's cognitive improvement and classroom behaviour. Since the ABs intervention demonstrates these positive effects, its implementation in schools can have a beneficial, sustainable and long-term impact on childhood health.

Key messages

• ABs intervention represents a cost-effective strategy to be implemented in the school settings regardless of the age and sex differences, to make the school a more dynamic environment.

• Despite the pandemic difficulties, the ABs intervention proved to be sustainable, and to have a positive effect on classroom behaviour by improving children’s concentration and attention in class.

Integrative Transcriptomic Analysis Reveals Distinctive Molecular Traits and Novel Subtypes of Collecting Duct Carcinoma

Collecting duct carcinoma (CDC) is a rare and highly aggressive kidney cancer subtype with poor prognosis and no standard treatments. To date, only a few studies have examined the transcriptomic portrait of CDC. Through integration of multiple datasets, we compared CDC to normal tissue, upper-tract urothelial carcinomas, and other renal cancers, including clear cell, papillary, and chromophobe histologies. Association between CDC gene expression signatures and in vitro drug sensitivity data was evaluated using the Cancer Therapeutic Response Portal, Genomics of Drug Sensitivity in Cancer datasets, and connectivity map. We identified a CDC-specific gene signature that predicted in vitro sensitivity to different targeted agents and was associated to worse outcome in clear cell renal cell carcinoma. We showed that CDC are transcriptionally related to the principal cells of the collecting ducts providing evidence that this tumor originates from this normal kidney cell type. Finally, we proved that CDC is a molecularly heterogeneous disease composed of at least two subtypes distinguished by cell signaling, metabolic and immune-related alterations. Our findings elucidate the molecular features of CDC providing novel biological and clinical insights. The identification of distinct CDC subtypes and their transcriptomic traits provides the rationale for patient stratification and alternative therapeutic approaches.

The Imola Active Breaks study: a new strategy in child public health to reduce sedentary

Background

Physical inactivity is worldwide considered one of the biggest public health problems of the 21st century. WHO recommended in children, at least 60 minute of Moderate Vigorous Physical activity (MVPA) per day, but low percentages comply with guidelines. Considering that children spend many hours at school, classroom is the ideal setting to increase their PA. Active Breaks (AB) are a 5-15-minute bouts of PA led by the teachers during academic lessons. The aim of the Imola AB study is to implement a 1-year intervention based on AB (10min/3per-day) in primary school as a new strategy to reduce inactivity. We present the baseline results.

Methods

Quasi-experimental pre-post study in 6-10aged primary school children, in Imola(Italy).We evaluated PA level with Actigraph accelerometers: time (in minutes) spent in MVPA Weekly and Daily (W-MVPA; D-MVPA) and Weekly Sedentary behaviours (W-SB).

Results

We recruited 152 children: N = 110 in Active Breaks experimental group (AB) and N = 42 in control group (CG). Actigraph's analysis showed that 42,5% of children in the ABG vs 31.0% in the CG reach the WHO recommendation (p=ns). We investigated baseline differences between groups using ANOVA dividing children by grade. In 3-4 grades: W-MVPA (AB = 318.3±15.5 vs CG = 310.4±98.0 p = 0.78); D-MVPA (AB = 53.0±20.3 vs CG = 51.8±16.3 p = 0.79);W-SB (AB = 6,687.5±375.3 vs CG = 6,754.7±281.0 p = 0.45). In 1grade: W-MVPA (AB = 376.1±127.9 vs CG = 300.3±120.0 p = 0.02); D-MVPA (AB = 62.7±21.3 vs CG = 50.0±20.0 p = 0.02); W-SB (AB = 6,436.0±496.0 vs CG = 6,373.3 ±1,532.0 p = 0.7).

Conclusions

Only the 39.2% of the total sample met the 60-minute/day of MVPA recommended. We found no significant baseline differences in PA level measured by Actigraph between CG and AB, excepted in 1 grade. The intervention implemented in the Imola AB study could be a good strategy to reduce sedentary in children and reach the WHO recommendation, thus contributing to the aims of the new Global Action Plan on PA 2018-2030.

Key messages

Less than 50% reach the WHO recommendations of PA. AB implemented in the Imola Study could be a public health school-based strategy to reduce sedentary and increase healthy behavior in children. Active breaks (AB) are emerging as a good strategy to increase the PA level, reducing the time in sedentary habits.

NCL Inhibition Exerts Antineoplastic Effects against Prostate Cancer Cells by Modulating Oncogenic MicroRNAs

Prostate cancer (PCa) is the most frequently diagnosed cancer in men and second most common cause of cancer-related deaths in the United States. Androgen deprivation therapy (ADT) is only temporarily effective for advanced-stage PCa, as the disease inevitably progresses to castration-resistant prostate cancer (CRPC). The protein nucleolin (NCL) is overexpressed in several types of human tumors where it is also mislocalized to the cell surface. We previously reported the identification of a single-chain fragment variable (scFv) immuno-agent that is able to bind NCL on the surface of breast cancer cells and inhibit proliferation both in vitro and in vivo. In the present study, we evaluated whether NCL could be a valid therapeutic target for PCa, utilizing DU145, PC3 (CRPC), and LNCaP (androgen-sensitive) cell lines. First, we interrogated the publicly available databases and noted that higher NCL mRNA levels are associated with higher Gleason Scores as well as with recurrent and metastatic tumors. Then, using our anti-NCL scFv, we demonstrated that NCL is expressed on the surface of all three tested cell lines and that NCL inhibition results in reduced proliferation and migration. We also measured the inhibitory effect of NCL targeting on the biogenesis of oncogenic microRNAs such as miR-21, -221 and -222, which was cell context dependent. Taken together, our data provide evidence that NCL targeting inhibits the key hallmarks of malignancy in PCa cells and may provide a novel therapeutic option for patients with advanced-stage PCa.

Tagging enhances histochemical and biochemical detection of Ran Binding Protein 9 in vivo and reveals its interaction with Nucleolin

The lack of tools to reliably detect RanBP9 in vivo has significantly hampered progress in understanding the biological functions of this scaffold protein. We report here the generation of a novel mouse strain, RanBP9-TT, in which the endogenous protein is fused with a double (V5-HA) epitope tag at the C-terminus. We show that the double tag does not interfere with the essential functions of RanBP9. In contrast to RanBP9 constitutive knock-out animals, RanBP9-TT mice are viable, fertile and do not show any obvious phenotype. The V5-HA tag allows unequivocal detection of RanBP9 both by IHC and WB. Importantly, immunoprecipitation and mass spectrometry analyses reveal that the tagged protein pulls down known interactors of wild type RanBP9. Thanks to the increased detection power, we are also unveiling a previously unknown interaction with Nucleolin, a protein proposed as an ideal target for cancer treatment. In summary, we report the generation of a new mouse line in which RanBP9 expression and interactions can be reliably studied by the use of commercially available αtag antibodies. The use of this line will help to overcome some of the existing limitations in the study of RanBP9 and potentially unveil unknown functions of this protein in vivo such as those linked to Nucleolin.

RANBP9 as potential therapeutic target in non-small cell lung cancer

Non-small cell lung cancer (NSCLC) remains the leading cause of cancer-related deaths in the Western world. Despite progress made with targeted therapies and immune checkpoint inhibitors, the vast majority of patients have to undergo chemotherapy with platinum-based drugs. To increase efficacy and reduce potential side effects, a more comprehensive understanding of the mechanisms of the DNA damage response (DDR) is required. We have shown that overexpressby live cell imaging (Incuyion of the scaffold protein RAN binding protein 9 (RANBP9) is pervasive in NSCLC. More importantly, patients with higher levels of RANBP9 exhibit a worse outcome from treatment with platinum-based drugs. Mechanistically, RANBP9 exists as a target and an enabler of the ataxia telangiectasia mutated (ATM) kinase signaling. Indeed, the depletion of RANBP9 in NSCLC cells abates ATM activation and its downstream targets such as pby live cell imaging (Incuy53 signaling. RANBP9 knockout cells are more sensitive than controls to the inhibition of the ataxia and telangiectasia-related (ATR) kinase but not to ATM inhibition. The absence of RANBP9 renders cells more sensitive to drugs inhibiting the Poly(ADP-ribose)-Polymerase (PARP) resulting in a "BRCAness-like" phenotype. In summary, as a result of increased sensitivity to DNA damaging drugs conferred by its ablation in vitro and in vivo, RANBP9 may be considered as a potential target for the treatment of NSCLC. This article aims to report the results from past and ongoing investigations focused on the role of RANBP9 in the response to DNA damage, particularly in the context of NSCLC. This review concludes with future directions and speculative remarks which will need to be addressed in the coming years.

Cancer-Derived Extracellular Vesicle-Associated MicroRNAs in Intercellular Communication: One Cell's Trash Is Another Cell's Treasure

Several non-protein-coding genomic regions, previously marked as "junk DNA", have been reported to be transcriptionally active, giving rise to non-coding RNA species implicated in fundamental biological and pathological processes. In particular, microRNAs (miRNAs), a class of small non-coding RNAs mediating post-transcriptional gene silencing, are causally involved in several human diseases, including various cancer types. Extracellular vesicles (EVs) are membranous structures physiologically released by most cell types. Initially, they were considered a "waste-removal" mechanism, through which cells could dispose unnecessary material and organelles. It is now widely demonstrated that EVs also play a critical role in intercellular communication, mediating the horizontal transfer of lipids, proteins, and genetic material. A paradigm shift in the biology of miRNAs was represented by the discovery that EVs, especially from cancer cells, contain miRs. EV-associated miRs act as autocrine, paracrine and endocrine factors, participating in cancer pathogenesis by modulating intercellular communication. Noteworthy, these formerly neglected molecules are now considered the next generation of cancer "theranostic" tools, with strong clinical relevance. In this review, we aim to summarize the most recent findings regarding EV-associated miRs in cancer pathogenesis and in the development of novel anti-neoplastic diagnostic and therapeutic approaches.

Abstract 3514: RANBP9 presence affects levels of Tip60 and activated p53 in lung cancer cells in response to DNA damage

Lung cancer is the leading cause of cancer-related deaths. Despite recent success with targeted and immune-therapies, DNA-damaging agents, such as platinum-based drugs, still represent the first-line of treatment. However, side effects and drug resistance limit their efficacy and use. We recently demonstrated that RAN Binding Protein 9 (RANBP9) plays a critical role in the DNA-damage response (DDR) of lung cancer cells. However, how it affects the mechanisms and outcome of the DDR is not known. In this regard, p53 activity is crucial for cell cycle arrest or programmed cell death. In particular, acetylation of p53 at lysine 120 by the Tat-Interacting Protein of 60 KDa (Tip60) is dispensable for p53-mediated growth arrest but is essential for p21 induction and p53-dependent apoptosis. It has been reported that RANBP9 and Tip60 co-localize. Here, we investigate whether RANBP9 affects Tip60-dependent activation of p53 and its relevance in deciding cell faith in response to DNA damage. For our study we used H1299, A549 and HeLa cells. By CRISPR/Cas9, we generated RANBP9 wild type (WT) and knockout (KO) A549 clones. We also established KO clones stably re-expressing RANBP9-FLAG. Cell response to DNA damage was assessed upon treatment with Ionizing Radiation (IR) and/or Cisplatin (CDDP). Interaction between RANBP9 with Tip60 was assessed by immunoprecipitation of transfected HeLa cell lysates. We show that RANBP9 and Tip60 co-immunoprecipitate either by pulling-down RANBP9 or Tip60. Using different deletion mutants of Tip60, we found that a region encompassing the Zinc Finger and part of the Histone Acetyl-Transferase domain is required for the interaction with RANBP9. Further, the enzymatic-dead Tip60 retained its ability to interact with RANBP9. Using p53 null H1299 cells, we established that this interaction is independent of p53. However, RANBP9 depletion affects both total and activated p53 (p-p53s15) levels after DNA damage. Re-expressing RANBP9 in stable KO clones rescued p53 levels. Upon CDDP treatment, p53 protein levels were higher in the clones stably re-expressing RANBP9 compared to the KO ones. Upon IR or CDDP treatment, p21 protein levels were higher in the presence of RANBP9. Finally, we found that Tip60 levels were higher in CDDP-treated and untreated WT cells comparing to the KO ones. Our results indicate that RANBP9 and Tip60 constitutively interact. The decrease of p53 in RANBP9 absence suggests that RANBP9 might favor p53 acetylation by Tip60 upon DNA damage. Further investigations will elucidate how RANBP9 affects the levels and the functions of Tip60. Also, we will measure the levels of p53-AcK120 both in the WT and KO clones. If p53-AcK120 is impaired when RANBP9 is absent, RANBP9 KO cells might undergo cell death instead of cell cycle arrest. Altogether, our results shed light on a potential RANBP9-Tip60-p53 axis at play during the DDR.

Citation Format: Shimaa Soliman, Arturo Orlacchio, Anna Tessari, Marina Capece, Rosa Visone, Carlo Croce, Dario Palmieri, Vincenzo Coppola. RANBP9 presence affects levels of Tip60 and activated p53 in lung cancer cells in response to DNA damage [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3514.

MicroRNAs for the Diagnosis and Management of Malignant Pleural Mesothelioma: A Literature Review

Malignant pleural mesothelioma (MPM) is a rare and aggressive tumor with a variable incidence among different countries. Occupational asbestos exposure is the most important etiological factor and a very long latency period is widely reported. In the early phase of the disease, clinical signs are absent or not specific. For this reason, the diagnosis is frequently achieved only in the advanced stages. The histopathological diagnosis per se is also very complex, and no known factor can predict the prognosis with certainty. Nonetheless, current survival rates remain very low, despite the use of standard treatments, which include surgery, chemotherapy and radiotherapy. The identification of new prognostic and/or diagnostic biomarkers, and the discovery of therapeutic targets is a priority and could lead to a real significant impact on the management of malignant pleural mesothelioma. In this scenario, the role of microRNAs is becoming increasingly relevant, with the promise of a quick translation in the current clinical practice. Despite the relative novelty of this field, the number of works and candidate microRNAs that are present in literature is striking. Unfortunately, to date the microRNAs with the most clinical relevance for MPM are still matter of debate, probably due to the variety of approaches, techniques, and collected samples. Although specific microRNAs (e.g., let-7, miR-15 and miR-16, miR-21, miR-34a, and the miR-200 family) have been reported several times from different groups, the heterogeneity of published data reinforces the need of more comprehensive and unified studies on this topic. In this review we collect and discuss the studies focused on the involvement of microRNAs in different aspects of MPM, from their biological role in tumorigenesis and progression, to their possible application as diagnostic, prognostic and predictive biomarkers. Lastly, we examine their potential value as for the design of therapeutic approaches that could benefit MPM patients.

Genetic ablation of interacting with Spt6 (Iws1) causes early embryonic lethality

IWS1 is an RNA-polymerase II (RNAPII)-associated transcription elongation factor whose biological functions are poorly characterized. To shed some light on the function of this protein at the organismal level, we performed a systematic tissue analysis of its expression and generated Iws1-deficient mice. A thorough immunohistochemical characterization shows that IWS1 protein is present in the nucleus of all cells in most of the examined tissues, with few notable exceptions. We also report that ablation of Iws1 consistently causes lethality at the pre-implantation stage with high expression of the gene in fertilized oocytes. In summary, we are providing evidence that Iws1 is expressed in all adult organs and it is an essential gene for mouse embryonic development.

RANBP9 affects cancer cells response to genotoxic stress and its overexpression is associated with worse response to platinum in NSCLC patients

Although limited by severe side effects and development of resistance, platinum-based therapies still represent the most common first-line treatment for non-small cell lung cancer (NSCLC). However, a crucial need in the clinical management of NSCLC is represented by the identification of cases sensitive to DNA damage response (DDR)-targeting drugs, such as cisplatin or PARP inhibitors. Here, we provide a molecular rationale for the stratification of NSCLC patients potentially benefitting from platinum compounds based on the expression levels of RANBP9, a recently identified player of the cellular DDR. RANBP9 was found overexpressed by immunohistochemistry (IHC) in NSCLC compared to normal adjacent tissues (NATs) (n = 147). Moreover, a retrospective analysis of 132 platinum-treated patients from the multi-centric TAILOR trial showed that RANBP9 overexpression levels are associated with clinical response to platinum compounds [Progression Free Survival Hazard Ratio _{(RANBP9 high vs low)} 1.73, 95% CI 1.15-2.59, p = 0.0084; Overall Survival HR _{(RANBP9 high vs low)} 1.99, 95% CI 1.27-3.11, p = 0.003]. Accordingly, RANBP9 KO cells showed higher sensitivity to cisplatin in comparison with WT controls both in vitro and in vivo models. NSCLC RANBP9 KO cells were also more sensitive than control cells to the PARP inhibitor olaparib alone and in combination with cisplatin, due to defective ATM-dependent and hyper-activated PARP-dependent DDR. The current investigation paves the way to prospective studies to assess the clinical value of RANBP9 protein levels as prognostic and predictive biomarker of response to DDR-targeting drugs, leading to the development of new tools for the management of NSCLC patients.

Abstract 473: miR-135b mediates gemcitabine sensitivity in breast cancer cells by modulating epithelial-to-mesenchymal transition and mTOR-signaling

Background: We previously identified miR-135b as a possible biomarker for gemcitabine sensitivity in metastatic breast cancer patients. Here we aimed to better understand the role of this microRNA in breast cancer cells in order to identify new clinically relevant approaches to revert gemcitabine resistance.

Methods: miR-135b KO MDA-MB-231 breast cancer cells were generated through CRISPR-Cas9 technology and tested for gemcitabine sensitivity by cell survival and apoptosis activation assays. Gene expression profile was performed by GeneChip® Human Transcriptome Array 2.0 (HTA 2.0 - Affymetrix). The One-Way between-subject ANOVA algorithm was used to calculate statistical significance of pairwise comparisons. The validation of different gene expression was assessed by qRT-PCR. The mesenchymal phenotype of miR-135b KO cells was tested by wound-healing and migration assay. mTOR pathway has been tested by Western blot analysis.

Results: miR-135b KO MDA-MB-231 showed increased resistance to gemcitabine than WT cells. Gene expression profiling of miR-135b WT and KO cells revealed the upregulation of several genes, including miR-21 and gene involved in the epithelial-to-mesenchymal transition (EMT) in the absence of the microRNA. Functional enrichment analysis indicated the deregulation of multiple tumor-associated pathways, including focal adhesion, senescence and autophagy. Accordingly, miR-135b KO cells showed higher migrating properties and expression of mesenchymal genes. Moreover, miR-135b KO cells showed deregulation of the mTOR-signaling pathway upon starvation or treatment with gemcitabine. Based on these observations, we assessed whether inhibition of mTOR activation using a clinically approved inhibitor (everolimus) could enhance gemcitabine sensitivity in the absence of miR-135b. Our data indicate that blocking mTOR pathway could represent a valid approach to revert resistance to gemcitabine even in cancer cells with low levels of miR-135b.

Conclusions: We identified several deregulated genes and pathways in the absence of miR-135b in breast cancer cells, in particular related to the EMT and mTOR pathway. These results confirm the role of miR-135b in breast cancer and pave the way for new studies for the combination of gemcitabine and mTOR inhibitors in a specific subset of metastatic breast cancer patients that could largely benefit from it.

Citation Format: Anna Tessari, Meghan Pawlikowski, Kareesma Parbhoo, Olivia Willetts, Marianna Hernandez, Giovanni Nigita, Ashley Braddom, Joseph J. Mills, Dario Palmieri, Carlo M. Croce. miR-135b mediates gemcitabine sensitivity in breast cancer cells by modulating epithelial-to-mesenchymal transition and mTOR-signaling [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 473.

Abstract LB-245: Multiple DNA-damage response pathways are modulated by RANBP9 protein in NSCLC

Non-small cell lung cancer (NSCLC) is the most prominent cause of cancer-related deaths in the world. The most indicated treatment for over 50% of NSCLC patients is represented by platinum-based chemotherapy. These compounds exert their biological effects by inducing DNA damages. Differently from normal cells, cancer cells frequently display a defective DNA Damage Response (DDR), which results in cancer cell death upon treatment with DNA-damaging agents. However, cancer cells up-regulate specific DDR mechanisms to cope with genotoxic stress, leading to resistance to conventional chemotherapies. For these reasons, a better understanding of cellular DDR mechanisms in tumors might help to identify 1) biomarkers predictive of DNA-repair defects and 2) targeted agents to inhibit tumor specific DNA-repair pathways. We have previously demonstrated that RANBP9 is a new phosphorylation target and signaling facilitator of ATM, one of the most important kinases in DDR. We have recently shown that RANBP9 is upregulated in lung cancer vs normal adjacent tissues, and its protein levels correlate with tumor stage. Importantly, low RANBP9 levels were associated to enhanced progression free survival and overall survival upon treatment with platinum-based compounds, in a cohort of more than 130 NSCLC patients. To gain molecular insights in the role of RANBP9 in DDR and sensitivity to genotoxic stress, we generated NSCLC cell lines where its expression was abrogated by CRISPR/Cas9. These models confirmed that absence of RANBP9 results in enhanced therapeutic effects of cisplatin and reduced activation of ATM-dependent DDR. Notably, we also observed that RANBP9 abrogation resulted in increased levels of polyADP-ribosylated chromatin proteins, without affecting total levels of poly(ADP-ribose) polymerase 1 (PARP1), another critical mediator of DDR. Conversely, we found reduced levels of PAR-glycohydrolase (PARG), a negative regulator of nuclear PAR levels, in response DNA-damaging agents. Based on these results, we hypothesized that RANBP9 levels could dictate the preferential DDR mechanism activated by lung cancer cells in response to genotoxic stress. Accordingly, preliminary evidences show that RANBP9-negative cells (PARP-dependent) display higher sensitivity to PARP inhibition. On the other hand, RANBP9-positive cells (ATM-dependent) are more sensitive to ATM inhbition. In summary, our study suggests that RANBP9 could act both as a positive and as a negative regulator of different mechanisms of DDR. These findings pave the way to clinical studies where RANBP9 levels could be used to inform the choice of the most effective genotoxic therapy and prevent resistance.

Citation Format: Anna Tessari, Kareesma Parbhoo, Meghan Pawlikowski, Matteo Fassan, Eliana Rulli, Claudia Foray, Alessandra Fabbri, Valerio Embrione, Monica Ganzinelli, Marina Capece, Massimo Broggini, Gabriella Farina, Mirko Marabese, Marina C. Garassino, Carlo Croce, Dario Palmieri, Vincenzo Coppola. Multiple DNA-damage response pathways are modulated by RANBP9 protein in NSCLC [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr LB-245.

Scorpins in the DNA Damage Response

The DNA Damage Response (DDR) is a complex signaling network that comes into play when cells experience genotoxic stress. Upon DNA damage, cellular signaling pathways are rewired to slow down cell cycle progression and allow recovery. However, when the damage is beyond repair, cells activate complex and still not fully understood mechanisms, leading to a complete proliferative arrest or cell death. Several conventional and novel anti-neoplastic treatments rely on causing DNA damage or on the inhibition of the DDR in cancer cells. However, the identification of molecular determinants directing cancer cells toward recovery or death upon DNA damage is still far from complete, and it is object of intense investigation. SPRY-containing RAN binding Proteins (Scorpins) RANBP9 and RANBP10 are evolutionarily conserved and ubiquitously expressed proteins whose biological functions are still debated. RANBP9 has been previously implicated in cell proliferation, survival, apoptosis and migration. Recent studies also showed that RANBP9 is involved in the Ataxia Telangiectasia Mutated (ATM) signaling upon DNA damage. Accordingly, cells lacking RANBP9 show increased sensitivity to genotoxic treatment. Although there is no published evidence, extensive protein similarities suggest that RANBP10 might have partially overlapping functions with RANBP9. Like RANBP9, RANBP10 bears sites putative target of PIK-kinases and high throughput studies found RANBP10 to be phosphorylated following genotoxic stress. Therefore, this second Scorpin might be another overlooked player of the DDR alone or in combination with RANBP9. This review focuses on the relatively unknown role played by RANBP9 and RANBP10 in responding to genotoxic stress.

Phase I study of tomuzotuximab, a glycoengineered therapeutic antibody against the epidermal growth factor receptor, in patients with advanced carcinomas

Background

Changes in glycosylation of the constant domain (Fc) of monoclonal antibodies (mAbs) enhance antibody-dependent cell-mediated cytotoxicity independently of downstream effects following receptor blockade by the antibody, thus extending their indication. We investigated the safety, pharmacokinetics, pharmacodynamics and antitumour activity of tomuzotuximab, an IgG1 glycoengineered mAb against the epidermal growth factor receptor with enhanced tumour cytotoxicity in a phase I dose-escalation study (NTC01222637).

Patients and methods

Forty-one patients with advanced solid tumours refractory to standard therapies received tomuzotuximab weekly (12–1370 mg) or two-weekly (990 mg) on a three-plus-three dose escalation design.

Results

A maximum tolerated dose was not reached. The most frequent treatment-related adverse events were infusion-related reactions in 31 (76%) patients (grade 3, 12%), mainly confined to the first dose, and skin toxicities (grade 1 or 2) in 30 (73%) patients. Hypomagnesaemia was observed in 9 out of 23 evaluable patients (39%). Similar to cetuximab, tomuzotuximab concentrations increased proportionally to dose from doses≥480 mg with a median terminal half life (t½) of 82 hours, range 55–113 hours. Antitumour activity included one complete response ongoing since more than 4.5 years in a patient with non-small-cell lung cancer and one partial response lasting 353 days in a patient with colorectal cancer. Twelve patients achieved stable disease (median, 166 days, range, 71–414 days) and two patients had prolonged control (>1 year) of their non-measurable disease.

Conclusion

Tomuzotuximab was safe and showed promising antitumour activity in heavily pretreated patients with advanced metastatic disease. A phase IIb trial of chemotherapy and weekly tomuzotuximab or cetuximab followed with maintenance therapy with the corresponding mAb in patients with recurrent or metastatic head and neck squamous cell carcinoma is ongoing.

Abstract A112: RanBP9 protects cells from genotoxic stress and increased expression is predictive of worse response to platinum in NSCLC patients

Platinum-based therapies currently represent the most common first-line treatment for non-small cell lung cancer (NSCLC). The efficacy of platinum compounds depends on the activation of the cellular DNA damage response (DDR), which leads to cancer cell death. However, severe toxic effects and development of resistance represent major limitations in the use of these drugs. Thus, a better mechanistic understanding and new prognostic and predictive biomarkers of the DDR are required to improve outcomes of NSCLC treatment. We have previously reported that RanBP9 (Palmieri et al., 2016), a poorly characterized scaffold protein, participates in the DDR and that its downregulation causes enhanced sensitivity to DNA damage induced by ionizing radiation. In the present study, we used immunohistochemical analysis to reveal that RanBP9 expression is significantly and commonly elevated in 178 lung tumors of different histotypes compared to their normal adjacent tissue (p&lt;0.02 - 0.001). We also show that knockout (KO) of RanBP9 in A549 NSCLC cell lines resulted in reduced DDR and higher levels of cisplatin-induced apoptosis both in vitro and in vivo. These findings were validated by a retrospective analysis of 134 NSCLC patients in which higher levels of RanBP9 associated with tumor stage (p&lt;0.0001), and poor response to platinum compounds as first-line treatment (PFS, HR (RanBP9 positive vs negative) 1.71, 95% CI 1.142 - 2.563, p = 0.0093). Finally, we show that ablation of RanBP9 is associated with overactivation of poly(ADP-ribose) polymerase (PARP) and increased cisplatin antineoplastic efficacy in combination with PARP inhibitors, indicating that the absence of RanBP9 results in a BRCAness-like phenotype. Overall, these results reveal that RanBP9 is a novel predictive biomarker of response to genotoxic treatments in NSCLC, paving the way to prospective studies aimed at assessing its clinical prognostic value and therapeutic targeting.

Citation Format: Anna Tessari, Kareesma Parbhoo, Meghan Pawlikowski, Matteo Fassan, Eliana Rulli, Claudia Foray, Alessandra Fabbri, Valerio Embrione, Monica Ganzinelli, Marina Capece, Moray J. Campbell, Massimo Broggini, Krista La Perle, Gabriella Farina, Sara Cole, Mirko Marabese, Joseph M. Amann, David P. Carbone, Marina C. Garassino, Carlo M. Croce, Dario Palmieri, Vincenzo Coppola. RanBP9 protects cells from genotoxic stress and increased expression is predictive of worse response to platinum in NSCLC patients [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2017 Oct 26-30; Philadelphia, PA. Philadelphia (PA): AACR; Mol Cancer Ther 2018;17(1 Suppl):Abstract nr A112.

Ran Binding Protein 9 (RanBP9) is a novel mediator of cellular DNA damage response in lung cancer cells

Ran Binding Protein 9 (RanBP9, also known as RanBPM) is an evolutionary conserved scaffold protein present both in the nucleus and the cytoplasm of cells whose biological functions remain elusive.

We show that active ATM phosphorylates RanBP9 on at least two different residues (S181 and S603). In response to IR, RanBP9 rapidly accumulates into the nucleus of lung cancer cells, but this nuclear accumulation is prevented by ATM inhibition. RanBP9 stable silencing in three different lung cancer cell lines significantly affects the DNA Damage Response (DDR), resulting in delayed activation of key components of the cellular response to IR such as ATM itself, Chk2, γH2AX, and p53. Accordingly, abrogation of RanBP9 expression reduces homologous recombination-dependent DNA repair efficiency, causing an abnormal activation of IR-induced senescence and apoptosis.

In summary, here we report that RanBP9 is a novel mediator of the cellular DDR, whose accumulation into the nucleus upon IR is dependent on ATM kinase activity. RanBP9 absence hampers the molecular mechanisms leading to efficient repair of damaged DNA, resulting in enhanced sensitivity to genotoxic stress. These findings suggest that targeting RanBP9 might enhance lung cancer cell sensitivity to genotoxic anti-neoplastic treatment.

Complete remission in metastatic breast cancer: expecting the unexpected-results of a cross-sectional study

BACKGROUND

Complete response (CR) in metastatic breast cancer (MBC) is rare. This study aims at analyzing the characteristics and outcome of MBC patients achieving CR.

METHODS

We performed a cross-sectional analysis of clinical data from a consecutive series of MBC patients admitted at the Division of Medical Oncology of Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy, achieving CR following treatment for systemic disease and with at least 2 years of follow-up.

RESULTS

Seventy-six MBC patients with CR were identified during a calendar year. 47 patients (61.8%) achieved CR more than once, for a total of 123 cases. Median age at MBC diagnosis was 56 years (range 30-76). 52 patients (68.4%) presented with recurrent disease, 24 (31.6%) with de novo metastatic disease. The majority of patients (80.3%) had hormone receptor (HR) positive and 26 (34.2%) had HER2 overexpressing MBC. 54 patients (71.1%) had only one site of metastatic disease. 33 patients (43.4%) received a local approach as part of their treatment and 67 (54.5%) achieved CR during maintenance therapy. CRs were durable, as after a median follow-up of 8.3 years (interquartile range 5.8-11.0 years) 42 patients (55.3%) were alive with no evidence of disease.

CONCLUSIONS

Durable CRs can occur after systemic therapy alone or after combined systemic and local treatments. Most cases presented CR in the presence of limited disease spreading, not necessarily on first-line therapy. Our study highlights the crucial role of multidisciplinary approach to MBC and the benefit of maintenance treatment.

miR-9 and miR-200 Regulate PDGFRβ-Mediated Endothelial Differentiation of Tumor Cells in Triple-Negative Breast Cancer

Organization of cancer cells into endothelial-like cell-lined structures to support neovascularization and to fuel solid tumors is a hallmark of progression and poor outcome. In triple-negative breast cancer (TNBC), PDGFRβ has been identified as a key player of this process and is considered a promising target for breast cancer therapy. Thus, we aimed at investigating the role of miRNAs as a therapeutic approach to inhibit PDGFRβ-mediated vasculogenic properties of TNBC, focusing on miR-9 and miR-200. In MDA-MB-231 and MDA-MB-157 TNBC cell lines, miR-9 and miR-200 promoted and inhibited, respectively, the formation of vascular-like structures in vitro Induction of endogenous miR-9 expression, upon ligand-dependent stimulation of PDGFRβ signaling, promoted significant vascular sprouting of TNBC cells, in part, by direct repression of STARD13. Conversely, ectopic expression of miR-200 inhibited this sprouting by indirectly reducing the protein levels of PDGFRβ through the direct suppression of ZEB1. Notably, in vivo miR-9 inhibition or miR-200c restoration, through either the generation of MDA-MB-231-stable clones or peritumoral delivery in MDA-MB-231 xenografted mice, strongly decreased the number of vascular lacunae. Finally, IHC and immunofluorescence analyses in TNBC specimens indicated that PDGFRβ expression marked tumor cells engaged in vascular lacunae. In conclusion, our results demonstrate that miR-9 and miR-200 play opposite roles in the regulation of the vasculogenic ability of TNBC, acting as facilitator and suppressor of PDGFRβ, respectively. Moreover, our data support the possibility to therapeutically exploit miR-9 and miR-200 to inhibit the process of vascular lacunae formation in TNBC. Cancer Res; 76(18); 5562-72. ©2016 AACR.

A phase I study of PankoMab-GEX, a humanised glyco-optimised monoclonal antibody to a novel tumour-specific MUC1 glycopeptide epitope in patients with advanced carcinomas

BACKGROUND

A phase I open-label dose-escalation study was conducted to define the safety, tolerability, and pharmacokinetics (PK) of PankoMab-GEX, a glyco-optimised humanised IgG1, with high affinity to a novel tumour-specific glycopeptide epitope of MUC1 (TA-MUC1) with excellent preclinical anti-tumour activity.

PATIENTS AND METHODS

Seventy-four patients with advanced TA-MUC1-positive carcinomas received PankoMab-GEX intravenously every 3 (Q3W), 2 (Q2W), or 1 (QW) week in doses of 1-2200 mg in a three-plus-three dose-escalation design until disease progression (NCT01222624).

RESULTS

No maximum tolerated dose was reached. Adverse events were mainly mild-to-moderate infusion-related reactions (IRRs) by the first infusion in 45% of patients. Only one dose-limiting toxicity, a grade III IRR, was observed. PankoMab-GEX exhibited linear PK over all doses. Mean terminal half-life was 189 ± 66 h (Q3W), without dose dependency. A target trough level ≥50 μg/mL was reached after one infusion with doses ≥1700 mg Q3W in 80% of patients. Clinical benefit in 60 evaluable patients included one complete response in a patient with ovarian cancer treated 483 d and confirmed disease stabilisation in 19 patients lasting a median (range) of 23 (10-109) weeks. All but two of the patients with clinical benefit had received a compounded total dose ≥700 mg over a 3-week period, including 8 of 12 (67%) patients with ovarian cancer.

CONCLUSION

PankoMab-GEX is safe, well tolerated, and showed promising anti-tumour activity in advanced disease. A phase IIb study is ongoing evaluating the efficacy of PankoMab-GEX as a maintenance therapy in advanced ovarian cancer.

A correlational study between signature, writing abilities and decision-making capacity among people with initial cognitive impairment

BACKGROUND

Some clinical conditions, including dementia, compromise cognitive functions involved in decision-making processes, with repercussions on the ability to subscribe a will. Because of the increasing number of aged people with cognitive impairment there is an acute and growing need for decision-making capacity evidence-based assessment.

AIMS

Our study investigates the relationship between writing abilities and cognitive integrity to see if it is possible to make inferences on decision-making capacity through handwriting analysis. We also investigated the relationship between signature ability and cognitive integrity.

METHODS

Thirty-six participants with diagnosis of MCI and 38 participants with diagnosis of initial dementia were recruited. For each subject we collected two samples of signature-an actual and a previous one-and an extract of spontaneous writing. Furthermore, we administered a neuropsychological battery to investigate cognitive functions involved in decision-making.

RESULTS

We found significant correlations between spontaneous writing indexes and neuropsychological test results. Nonetheless, the index of signature deterioration does not correlate with the level of cognitive decline.

DISCUSSION

Our results suggest that a careful analysis of spontaneous writing can be useful to make inferences on decision-making capacity, whereas great caution should be taken in attributing validity to handwritten signature of subjects with MCI or dementia.

CONCLUSIONS

The analysis of spontaneous writing can be a reliable aid in cases of retrospective evaluation of cognitive integrity. On the other side, the ability to sign is not an index of cognitive integrity.

Gene-expression profiling of collecting duct carcinoma of the kidney

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Background: Collecting duct carcinoma (CDC) of the kidney is a rare tumor, originating from renal medulla, characterized by younger age at diagnosis and poor prognosis. Since targeted therapies are currently not available for CDC, we aimed to identify the most deregulated pathways in this type of cancer to gain insights into new molecular targets. Methods: Total RNA was extracted from FFPE samples of primary CDC (n=9), clear cell carcinoma (CCC, n=7) and healthy normal (n=7) adjacent renal tissues (23 total samples). Gene expression profile was performed by GeneChip Human Transcriptome Array 2.0 (HTA 2.0 -Affymetrix). The One-Way between-subject ANOVA algorithm was used to calculate statistical significances of pairwise comparisons. Transcripts with a linear fold change (f.c.) of <-2/>2 (p-value<0.05) were included in the study. Functional enrichment analysis identified the most deregulated pathways in CDC. Results: A total of 1,079 genes (827 coding, 252 non-coding) were significantly deregulated comparing CDC, CCC and normal kidney (p<0.05). In CDC vs normal tissue comparison, 484 genes (339 coding, 145 non-coding) are significantly up-regulated, and 49 (40 coding, 9 non-coding) down regulated in tumors (p<0.05). The 4 most highly expressed transcripts in CDC are currently unknown, requiring further studies. Among the most altered known transcripts, we identified FN1 (f.c. 6.33), miR-21 (f.c. 4.01), KNG1 (f.c. -9.4) and AQP2 (f.c. -6.03), whose deregulation was previously associated with advanced disease and lower survival in renal cancer, supporting the quality of our analysis. Functional enrichment analysis indicated a strong downregulation of transcripts associated with histone modifications, function of cytoplasmic ribosomal proteins, senescence, autophagy and focal adhesion in CDC vs both CCC and normal tissues. Conclusions: Our analysis identifies several coding and non-coding transcripts differentially expressed in CDC vs CCC and normal kidney, resulting in alteration of a number of cellular pathways associated with cancer pathogenesis, progression and prognosis. These results pave the way to a deeper understanding of a rare tumor as CDC, driving the development of new, targeted therapies for this aggressive disease.

Abstract C17: Role of miR-135b in gemcitabine sensitivity for metastatic breast cancer patients

Background: MicroRNAs are a class of small non-coding RNAs that modulate gene expression at post-transcriptional level, resulting crucial in many physiological and pathological processes. Their involvement in cancer initiation and tumor progression has been clearly established, as well as their linkage with chemoresistance. Gemcitabine is a nucleoside analog used in the treatment of metastatic breast cancer (MBC), characterized by a favorable safety profile. Only a small percentage of pts show a strong and prolonged response to this drug, thus suggesting the need of predictive biomarkers. Here, we aimed to identify microRNAs whose expression could be related to gemcitabine sensitivity in MBC.

Methods: 24 MBC pts were treated with gemcitabine as single-agent therapy from 1999 to 2011 at Fondazione IRCCS Istituto Nazionale Tumori (Milan). They were selected and classified by the response to the treatment (11 gemcitabine sensitive, stable or partial response after &gt;24 weeks of treatment, and 13 gemcitabine resistant, progressive disease within 16 weeks from the first drug administration). MicroRNA expression profiling was performed by Nanostring nCounter Technology using RNA from FFPE metastatic lesions. Biological normalization was executed to correct for differences in sample abundances. Each sample was normalized to the geometric mean of the top 100 most highly expressed microRNAs. Student's t test was used to calculate statistical significances of pairwise comparisons. The nCounter analysis was validated on a wider population of 50 MBC pts (17 sensitive and 33 resistant) by qRT-PCR.

The correlation between microRNA expression levels and gemcitabine half maximal inhibitory concentration (IC50) was evaluated using different BC cell lines. Finally, gemcitabine sensitivity was assessed on these cell lines by cell survival assays following exogenous modulation of microRNA expression levels.

Results: Median age at diagnosis was 47 yrs (range 21-74 yrs). Hormone receptors were positive in thirty-one pts (62%), while Her2 in 15 cases (30%). Soft tissues were the most frequent site of metastasis (84%), followed by bone (64%), liver (36%), lung (34%) and CNS (16%). Sixteen pts (32%) had local recurrences. Median number of chemotherapies and endocrine therapies received prior to gemcitabine was 3 (range 1-6) and 2 (range 1-5) respectively.

From the nCounter analysis, a subset of 20 microRNAs was significantly deregulated (p&lt;0.001) between sensitive and resistant pts. Among them, the three most relevant (miR-135b, miR-146b and miR-155) were selected for further investigation. RT-PCR validation confirmed microRNA expression profiling data on the wider cohort of 50 pts (p&lt;0.05). In vitro studies confirmed the correlation between miR-135b levels and gemcitabine sensitivity in different BC cell lines. Moreover, the exogenous upregulation of this microRNA increased the response to the drug.

Conclusions: We identified miR-135b, miR-146b and miR-155 as potentially predictive for gemcitabine sensitivity in MBC pts. In particular, miR-135b appears to be causally involved in BC cells response to gemcitabine. These results pave the way to a better understanding of the molecular mechanisms underlying gemcitabine resistance in BC, and may have a clinical impact to identify those patients expected to obtain strong and prolonged benefits from this well-tolerated treatment.

Citation Format: Anna Tessari, Dario Palmieri, Giovanni Nigita, Dario Veneziano, Sara Cresta, Biagio Paolini, Maria Silvia Cona, Taylor Vargo, Erika Reese, Tyler Sheetz, Vincenzo Coppola, Filippo De Braud, Carlo M. Croce. Role of miR-135b in gemcitabine sensitivity for metastatic breast cancer patients. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr C17.

Abstract C171: Human anti-Nucleolin recombinant immunoagents as new potential tools for melanoma treatment

Immunotherapy and immune-based anti-cancer molecules represent a valid strategy to fight cancer. However, the choice of tumor-specific surface molecules for the selective targeting of cancer cells still represents a critical step in the study design for the development of new therapeutic approaches. Notably, the development of phage-display technology for the selection of fully human single chain antibody fragments (scFvs) and complete antibodies directed toward tumor-associated antigens has represented a significant advancement for immunotherapy.

Nucleolin (NCL) is one of the most abundant non-ribosomal proteins in the nucleolus. NCL is frequently up-regulated in cancer and in cancer-associated endothelial cells compared to normal tissues, where it is also present on the cell surface. Altered NCL expression and localization results in oncogenic effects such as stabilization of oncogenic mRNAs and microRNAs (miRNAs). Particularly, we demonstrated that NCL enhances the maturation of specific miRNAs (including miR-21, miR-221 and miR-222) causally involved in cancer pathogenesis, aggressiveness, metastatic potential and resistance to several anti-neoplastic treatments.

Because of its oncogenic role and specific expression on cancer cell surface, NCL represents an attractive target for anti-neoplastic therapies. To produce a new anti-NCL molecule with significant potential for clinical applications, we took advantage of phage-display technology to isolate a fully human single chain Fragment variable (scFv), named 4LB5, which binds with high affinity to the RNA binding domain (RBD) of NCL. In our previous study we demonstrated that 4LB5 binds NCL on the surface of aggressive breast cancer cells and inhibits their proliferation both in vitro and in vivo, representing the prototype of a new class of immune-based anti-NCL compounds.

Since NCL expression has been previously reported on the cell surface of skin cancer cell lines and up-regulation of NCL-dependent microRNAs was described in human melanomas, the objective of this project was the assessment of 4LB5 as a potential tool for melanoma therapy.

To this aim, the recombinant scFv was expressed as His6-fusion protein in E.Coli and purified by affinity chromatography, as previously described. By using Enzyme-Linked Immunosorbent Assays (ELISA), we demonstrated a significant binding of 4LB5 to the cell surface of different melanoma cell lines of both human and mouse origins. Notably, inhibition of NCL expression by siRNA transfection reduced the binding of 4LB5 to the cell surface of these cell lines, further supporting its specificity against NCL. Then, we assessed the potential effects of 4LB5 treatment on cell proliferation. Colony formation assays demonstrated that 4LB5 significantly affected cell proliferation of both human and mouse melanoma cell lines.

Our results, in agreement with previously reported data, further support the potential activity of 4LB5 as a tool for cancer therapy, paving the way for additional investigations aimed to fully elucidate the molecular mechanisms affected by this scFv and resulting in its anti-neoplastic therapy in human melanomas. Furthermore, this study supports the idea that anti-NCL immunoagents might represent a class of new anti-cancer compounds with a strong clinical relevance for a wide range of human tumors.

Citation Format: Ashley Braddom, Timothy Richmond, Tyler Sheetz, Erika Reese, Anna Tessari, Kathleen Tober, Christin E. Burd, Claudia De Lorenzo, Edward W. Martin, Jr., Vincenzo Coppola, Michael F. Tweedle, Tatiana Oberyszyn, Carlo M. Croce, Dario Palmieri. Human anti-Nucleolin recombinant immunoagents as new potential tools for melanoma treatment. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr C171.

Abstract LB-164: Ran Binding Protein 9 (RanBP9) is a novel mediator of cellular DNA damage response in lung cancer cells

Currently, most of the anti-neoplastic treatments for lung cancer patients are based on DNA-damaging cytotoxic therapies such as platinum-containing compounds and radiotherapy. Therefore, a better understanding of the molecular mechanisms involved in the cellular response to genotoxic stresses is required in order to improve the clinical management of lung cancer.

Ran Binding Protein 9 (RanBP9, also known as RanBP-M) is a ubiquitous and evolutionary conserved scaffold protein that shuttles between the nucleus and the cytoplasm, and interacts with many major players in tumor biology. However, its biological functions are not well studied and still debated.

Here, we show that RanBP9 interacts with and is phosphorylated by ATM, one of the apical activators of the DNA damage response (DDR) following DNA Double-Strand Breaks (DSBs). Following ATM-dependent phosphorylation, RanBP9 rapidly accumulates into the nucleus of lung cancer cells. By using three different lung cancer cell lines (A549, H460, and H1299), we found that stable silencing of RanBP9 (ShRanBP9) significantly affects the DDR. In fact, stable ShRanBP9 clones display a delayed and/or reduced activation of key components of the cellular response to Ionizing Radiation (IR), including ATM, Chk2, H2AX-γ and p53. Accordingly, abrogation of RanBP9 expression significantly affected Homology-Directed repair of damaged DNA. On the other hand, stable silencing of RanBP9 results in increased IR-induced senescence and apoptosis.

In summary, here we present evidence that RanBP9 is a novel mediator of the cellular DDR, whose recruitment into the nucleus upon IR is dependent on ATM kinase activity. In turn, nuclear RanBP9 participates to the efficient activation of cellular DDR. On the contrary, its absence hampers the repair of damaged DNA following DSBs, resulting in enhanced lung cancer sensitivity to genotoxic stresses.

Taken together, our findings suggest that targeting RanBP9 might represent a new potential approach to increase sensitivity of lung cancer cells to genotoxic anti-neoplastic treatments.

Citation Format: Dario Palmieri, Mario Scarpa, Anna Tessari, Rexhep Uka, Foued Amari, Cindy Lee, Timothy Richmond, Tyler Sheetz, Jeffrey Parvin, Thomas Ludwig, Carlo M. Croce, Vincenzo Coppola. Ran Binding Protein 9 (RanBP9) is a novel mediator of cellular DNA damage response in lung cancer cells. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr LB-164. doi:10.1158/1538-7445.AM2015-LB-164

Everolimus in advanced solid tumors: when to start, early or late?

Everolimus is an oral derivative of rapamycin which acts as a signal transduction inhibitor. It targets the mammalian target of rapamycin (mTOR), a key serine/threonine kinase regulating cell growth and angiogenesis. Everolimus has been approved for the treatment of pancreatic neuroendocrine tumors (pNETs), metastatic renal cell carcinoma (mRCC), and breast carcinoma. The activity of everolimus was demonstrated in three phase III randomized placebo-controlled trials, RADIANT-3, RECORD 1 and BOLERO 2, in patients with pNETs, mRCC and breast carcinoma, respectively. All three trials reported a statistically significant increase in median progression-free survival, the primary endpoint of the studies, in favor of everolimus. The absence of an overall survival benefit could be related to the cross-over design and subsequent therapies. The focus of our paper is on the best timing to start treatment with everolimus, while additional questions concern the opportuneness of intermittent use of everolimus specifically in long-responding patients. Lastly, we suggest this treatment could be optimized on the basis of patient and disease characteristics.

Overview of diagnostic/targeted treatment combinations in personalized medicine for breast cancer patients

Breast cancer includes a body of molecularly distinct subgroups, characterized by different presentation, prognosis, and sensitivity to treatments. Significant advances in our understanding of the complex architecture of this pathology have been achieved in the last few decades, thanks to new biotechnologies that have recently come into the research field and the clinical practice, giving oncologists new instruments that are based on biomarkers and allowing them to set up a personalized approach for each individual patient. Here we review the main treatments available or in preclinical development, the biomolecular diagnostic and prognostic approaches that changed our perspective about breast cancer, giving an overview of targeted therapies that represent the current standard of care for these patients. Finally, we report some examples of how new technologies in clinical practice can set in motion the development of new drugs.

Abstract P4-07-18: PDGFRbeta-induced miR-9 is up-regulated in triple negative breast cancer

miR-9 has been described as an oncogenic microRNA associated to a metastatic phenotype and able to induce EMT (epithelial-to-mesenchymal transition) through direct targeting of E-cadherin. However, data available concerning the expression and the role of this microRNA in different subgroups of breast cancer are still not exhaustive.

Evaluating miR-9 expression by Real-Time PCR in a series of 92 breast cancer specimens (35 luminal, 36 HER2, 21 triple negative), we found that this microRNA is increasingly higher in HER2 and Triple Negative versus ER positive patients (fold change 3 and 8 respectively).

Moreover, preliminary analysis of miR-9 expression in correlation with bio-pathological features and clinical data also indicates a trend in association with disease progression.

Triple Negative Breast Cancers represent a very aggressive breast cancer subgroup, still lacking specific markers for an effective targeted therapy; we investigated whether miR-9 might play a role in the biology of this tumor subtype. Preliminary data indicate that miR-9 is activated downstream PDGFRbeta, which represents a crucial player in the aggressive phenotype of Triple Negative Breast Cancer.

In summary, here we show that miR-9 is significantly upregulated in triple negative breast cancer in comparison with other breast cancer subgroups and is activated downstream PDGFRbeta.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P4-07-18.

Role of BAX for outcome prediction in gastrointestinal malignancies

Our group and numerous others have shown in both preclinical and clinical studies that the proapoptotic mediator BAX may be deregulated through gene mutation or loss of protein expression, affecting resistance to chemotherapy and radiotherapy in several cancer types. However, BAX is also involved in cancer development and may related to prognosis, independently of treatment outcome. The clinical impact of BAX status in gastrointestinal malignancies remains controversial, although it is generally hypothesized that high expression may be a positive prognostic factor and predict increased efficacy of chemotherapy (with particular regard to platinum derivatives). The present review aims to provide updated information on BAX as potential prognostic and/or predictive biomarker in gastroesophageal and colorectal cancers, as well as in other less studied gastrointestinal malignancies.

Pathologic response, KRAS status, and bevacizumab: The Bermuda triangle for outcome prediction after hepatic colorectal cancer metastases (HCRM) resection

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Background: Clinicopathologic factors are insufficient to stratify prognosis after HCRM resection. The identification of prognostic biomarkers is an unmet clinical need. Even if the prognostic role of KRAS mutations in the metastatic setting is controversial, recent data hypothesized a correlation to worse outcome after HCRM resections. This analysis evaluated the correlation between KRAS mutation, pathological response and outcome. Methods: Fifty-eight pts with HCRM were resected at National Cancer Institute of Milan from 2007 to 2012 following bevacizumab (Bev) (n=30) or cetuximab (Cmab) (n=28) based neoadjuvant regimens. Tumor regression grade (TRG) was classified from TRG 1 for pathological complete response (pCR), to TRG5 for no response; TRG 1-3 for response; TRG 4-5 for scarce/no response. KRAS exons 2 to 4 were sequenced by direct PCR. Results: KRAS missing in 3 pts (1 Bev/2 Cmab), mutated in 23 (42%) vs wild-type in 32 (58%), mutated in 18 (62%) of Bev group vs 5 (19%) of Cmab. Mean TRG: 2.9 (2.2-4) in Bev vs 3.8 (3-5) in Cmab group (p=0.04 at Kruskal-Wallis test). Pathological response higher for Bev vs Cmab (70% vs 39%; p=0.037 at Chi-square test). Bev also increased pCRs (20% vs 0%, p=0.024 at Fisher’s test). Pathological response higher for KRAS mutant vs wild-type (70% vs 41%; p=0.003 at Chi-square test). At log-rank test, DFS significantly shorter for KRAS mutated vs wild-type (7.6 vs 14.6 months; p=0.05), and for TRG4-5 vs TRG1-3 (8.1 vs 15.3 months; p=0.02), while no difference observed according to treatment. OS data are not mature. Multivariable Cox model for DFS shown in the Table. Conclusions: After Bev-based neoadjuvant treatment, patients with KRAS mutated HCRM and without good pathological response may have the worst outcome after curative resection. [Table: see text]

Hepatic trans-arterial chemoembolization (TACE) in metastatic breast cancer

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Background: Liver metastasis is one of the most frequent cause of death in breast cancer patients. Among loco-regional approaches available for solid tumor liver metastasis, TACE allows a prolonged intra-lesion exposure to chemotherapeutic agents. Initial studies have highlighted a benefit in terms of response rate (RR) and overall survival (OS) in breast cancer patients treated with TACE versus systemic chemotherapy. Methods: We have retrospectively evaluated 14 patients affected by breast cancer with liver metastasis. Patients had been selected for liver TACE according to the presence of liver metastasis as only site of disease, or in the event of further sites of metastasis that were stable or in response from the previous treatment. All the patients received one or more TACE with DC-Bead (Biocompatibles UK) 100-300 micron, loaded with a chemotherapeutic agent (doxorubicin, paclitaxel).The systemic therapy received by patients before TACE could be confirmed or changed according to disease response. Objective of the study was to evaluate the response rate to TACE and its correlation with the response to the very last treatment performed before it. As surrogate of efficacy, time to progression (TTP) and OS were analyzed. Results: Among the 14 treated patients (5 heavily pretreated, with more than three lines of chemotherapy) only one obtained a complete remission (RC). Four patients presented a partial remission (PR). Three of them were progressing from previous treatment and one had a PR. Stable disease (SD) after TACE was obtained in four cases: two of them had a progressive disease (PD) before TACE and two had a responsive disease. Five patients did not respond to TACE (one with PR from the previous line of therapy). Median TTP observed in responsive patients (CR + PR) was 4.5 times higher than non-responders (PD) (13.2 vs. 2.9 months). Patients with SD had a median TTP of 4.3 months. Median OS of responsive patients was 25.6 months vs. 17.5 and 19.2 months of patients with SD or PD respectively. Conclusions: In our experience, chemoembolization can represent a valid therapeutic option in breast cancer patients with liver metastasis, independently from the response to the previous systemic therapy, and may prolong survival.

Gain of ALK gene copy number to predict lack of response to anti-EGFR treatment in advanced chemorefractory colorectal cancer (CRC) with KRAS/NRAS/BRAF/PI3KCA wild-type status

3641

Background: KRAS, BRAF, NRAS and exon 20 PIK3CA quadruple wild-type CRC is associated with 41.2% response rate to anti-EGFR treatments. Even in molecular characterized patients, there is still a subset of non responders. The identification of additional predictive biomarkers is an unmet clinical need for treatment personalization. Alterations of ALK oncoprotein may interfere with the biological activity of EGFR through cross-talk of downstream signalling pathways. Methods: This retrospective analysis aimed to investigate the correlation between ALK gene copy number (GCN), assessed by fluorescence in situ hybridization (FISH), and clinical outcome in KRAS/NRAS/BRAF/PI3KCA wild-type chemorefractory advanced CRC patients receiving cetuximab or panitumumab. FISH was perfomed with break-apart ALK (2p23) probes and gain of ALK GCN was defined as a mean of 3 to 5 signals in ≥10% of cells and amplification as ≥6 signals. Association of ALK status with RECIST response was performed by Fisher’s exact test. Results: Forty-one patients were identified, of whom 17 (41%) were ALK GCN positive, whereas the remaining 24 cases (59%) were ALK GCN negative. No ALK translocations were detected. Overall response rate was 19/41 (46%). We observed a partial response in 3/17 patients with ALK GCN positive versus 16/24 patients with ALK GCN negative (18% versus 67%, respectively; P=0.0036). Kaplan-meier curves for comparison of median progression-free and overall survival, as well as correlation with ALK expression by immunohistochemistry, will be presented at the Meeting exploring the whole National Cancer Institute data-set. Conclusions: In this study population with KRAS/NRAS/BRAF/PI3KCA wild-type tumors, the response rate greater than 40% is in line with literature data. ALK GCN may be a biomarker for clinical outcome prediction in advanced chemorefractory CRC patients treated with cetuximab or panitumumab.