Blockade of growth hormone receptor signaling by using pegvisomant: A functional therapeutic strategy in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is an aggressive neoplasm with poor clinical outcome because most patients present at an advanced stage, at which point curative surgical options, such as tumor excision or liver transplantation, are not feasible. Therefore, the majority of HCC patients require systemic therapy. Nonetheless, the currently approved systemic therapies have limited effects, particularly in patients with advanced and resistant disease. Hence, there is a critical need to identify new molecular targets and effective systemic therapies to improve HCC outcome. The liver is a major target of the growth hormone receptor (GHR) signaling, and accumulating evidence suggests that GHR signaling plays an important role in HCC pathogenesis. We tested the hypothesis that GHR could represent a potential therapeutic target in this aggressive neoplasm. We measured GH levels in 767 HCC patients and 200 healthy controls, and then carried out clinicopathological correlation analyses. Moreover, specific inhibition of GHR was performed in vitro using siRNA and pegvisomant (a small peptide that blocks GHR signaling and is currently approved by the FDA to treat acromegaly) and in vivo, also using pegvisomant. GH was significantly elevated in 49.5% of HCC patients, and these patients had a more aggressive disease and poorer clinical outcome (P<0.0001). Blockade of GHR signaling with siRNA or pegvisomant induced substantial inhibitory cellular effects in vitro. In addition, pegvisomant potentiated the effects of sorafenib (P<0.01) and overcame sorafenib resistance (P<0.0001) in vivo. Mechanistically, pegvisomant decreased the phosphorylation of GHR downstream survival proteins including JAK2, STAT3, STAT5, IRS-1, AKT, ERK, and IGF-IR. In two patients with advanced-stage HCC and high GH who developed sorafenib resistance, pegvisomant caused tumor stability. Our data show that GHR signaling represents a novel “druggable” target, and pegvisomant may function as an effective systemic therapy in HCC. Our findings could also lead to testing GHR inhibition in other aggressive cancers.

Disruption of Growth Hormone Receptor Signaling Abrogates Hepatocellular Carcinoma Development

Introduction

Hepatocellular carcinoma (HCC) is the most common type of primary liver cancers. It is an aggressive neoplasm with dismal outcome because most of the patients present with an advanced-stage disease, which precludes curative surgical options. Therefore, these patients require systemic therapies that typically induce small improvements in overall survival. Hence, it is crucial to identify new and promising therapeutic targets for HCC to improve the current outcome. The liver is a key organ in the signaling cascade triggered by the growth hormone receptor (GHR). Previous studies have shown that GHR signaling stimulates the proliferation and regeneration of liver cells and tissues; however, a definitive role of GHR signaling in HCC pathogenesis has not been identified.

Methods

In this study, we used a direct and specific approach to analyze the role of GHR in HCC development. This approach encompasses mice with global (Ghr-/- ) or liver-specific (LiGhr-/- ) disruption of GHR expression, and the injection of diethylnitrosamine (DEN) to develop HCC in these mice.

Results

Our data show that DEN induced HCC in a substantial majority of the Ghr+/+ (93.5%) and Ghr +/- (87.1%) mice but not in the Ghr-/- (5.6%) mice (P < 0.0001). Although 57.7% of LiGhr-/- mice developed HCC after injection of DEN, these mice had significantly fewer tumors than LiGhr+/+ (P < 0.001), which implies that the expression of GHR in the liver cells might increase tumor burden. Notably, the pathologic, histologic, and biochemical characteristics of DEN-induced HCC in mice resembled to a great extent human HCC, despite the fact that etiologically this model does not mimic this cancer in humans. Our data also show that the effects of DEN on mice livers were primarily related to its carcinogenic effects and ability to induce HCC, with minimal effects related to toxic effects.

Conclusion

Collectively, our data support an important role of GHR in HCC development, and suggest that exploiting GHR signaling may represent a promising approach to treat HCC.

Enhancing Antigen Retrieval to Unmask Signaling Phosphoproteins in Formalin-fixed Archival Tissues

The introduction of targeted therapy has revolutionized cancer treatment. Nonetheless, for this approach to succeed, it is crucial to identify the targets, particularly when activated, in tumor tissues. Phosphorylation is a posttranslational modification that causes activation of numerous oncogenic protein kinases and transcription regulators. Hence, phosphoproteins is a class of biomarkers that has therapeutic and prognostic implications directly relevant to cancer patients' management. Despite the progress in histopathology methodology, analysis of the expression of phosphoproteins in tumor tissues still represents a challenge owing to preanalytical and analytical factors that include antigen retrieval strategies. In this study, we tested the hypothesis that optimizing antigen retrieval methods will improve phosphoproteins unmasking and enhance their immunohistochemical staining signal. We screened 4 antigen retrieval methods by using antibodies specific for 3 oncogenic phosphoproteins to stain human lymphoma tumors that were developed in severe combined immunodeficiency mice and subsequently fixed in formalin for 2 years. Then, we used antibodies specific for 15 survival phosphoproteins to compare the most effective method identified from our screening experiment to the antigen retrieval method that is most commonly utilized. Using the antigen retrieval buffer Tris-EDTA at pH 9.0 and heating for 45 minutes at 97°C unmasked and significantly enhanced the staining of 9 of the 15 phosphoproteins (P<0.0001). Our antigen retrieval approach is cost effective and feasible for clinical and research settings. We anticipate that combining this approach with the newly proposed methods to improve tissue fixation will further improve unmasking of phosphoproteins in human and animal tissues.

Few UK vascular centres offer a fully NICE-compliant supervised exercise programme: a national audit

INTRODUCTION

To determine the current (pre-COVID-19) provision of supervised exercise training (SET) for patients with peripheral arterial disease (PAD) in UK Vascular Centres.

METHODS

Hospital Trusts delivering vascular care to patients with PAD were identified from the National Vascular Registry and asked to complete an online questionnaire on their provisions for SET. If a centre offered SET, they were asked questions to determine whether the programme was compliant with NICE guidelines and the difficulties they faced delivering the service. If centres did not offer SET, they were asked what obstacles prevented them implement SET.

RESULTS

Of the 78 UK vascular centres, 59 (76%) responded and were included in the audit. Of these, 27 (46%) were able to offer SET but only 21 (36%) could offer it to all their patients with PAD. Only four (6.8%) offered SET that was fully compliant with current NICE guidelines. Reasons identified included insufficient funding, lack of resource and poor patient compliance.

CONCLUSIONS

The benefits of SET are well established yet the availability of the service in the UK is poor. The reasons for this are readily identified but have not yet been overcome. Research on novel methods of delivering supervised exercise that mitigates existing barriers, such as home exercise with remote monitoring, should be prioritised to facilitate optimal management for our patients with PAD.

Inorganic nitrate attenuates the systemic inflammatory response in typhoid vaccine-induced endothelial dysfunction in healthy volunteers

Background

Inflammatory responses underlie the development of endothelial dysfunction in CVD, however, therapeutics that might target this pathway have not been forthcoming. A key pathogenic mechanism mediating endothelial dysfunction is a reduction in bioavailable (eNOS-derived) nitric oxide (NO). Activation of the non-canonical pathway for in-vivo NO generation might offer an approach to improve NO levels and recover vascular function in pre-clinical models of CVD. Whether this might occur in humans is unknown.

Purpose

We hypothesize that consumption of inorganic nitrate will lead to increases in bioavailable NO and thus attenuate the inflammatory pathways leading to typhoid vaccine-induced endothelial dysfunction in healthy volunteers.

Methods

Healthy male volunteers were recruited (n=78) and randomized to receive either beetroot juice containing 8–10mmol nitrate or placebo (nitrate-deplete) juice once daily for 6 days. Participants underwent serial measurements of BP, FMD and GTN-induced brachial artery dilatation, and haematology and biochemistry, before and after typhoid vaccination. Blood, urine and saliva nitrite and nitrate were quantified using ozone chemiluminescence, and leukocyte flow cytometry analysis was conducted.

Results

8-hours post-vaccine endothelial function was depressed in placebo-treated volunteers, however this was prevented in nitrate-treated volunteers. This dysfunction was due to impaired endothelial function since responses to GTN were unaffected either by vaccination or dietary intervention (p=0.981). Dietary nitrate resulted in an increase in plasma (p&lt;0.0001), urine (p=0.0006) and saliva (p&lt;0.0001) nitrate, and urine (p=0.0354) and saliva (p&lt;0.0001) nitrite levels. There was a reduction in the proportions of CD14++/CD16+intermediate monocytes in nitrate-treated participants after vaccine (p=0.016, change from baseline between groups). In the nitrate-treated group, less CD14++/CD16+ intermediate monocyte CD62L expression was identified post-vaccine (p=0.0122), compared to placebo, with no difference in soluble plasma CD62L between groups (p=0.875). CD11b median fluorescence intensity was increased in CD3+/CD4+ T-lymphocytes in nitrate-treated volunteers (p=0.0095).

Conclusions

Dietary nitrate reduced BP, as previously shown, indicating efficacy of the intervention. Importantly, we also now show for the first time that inorganic nitrate suppresses the systemic inflammatory response, specifically by reducing the numbers and activation state of CD14++/CD16+ intermediate monocytes. Furthermore, an increased expression of CD3+/CD4+ T-cell CD11b and preserved FMD in healthy volunteers treated with nitrate, suggests an anti-inflammatory phenotype, induced by the intervention, leading to improved endothelial function. Inorganic dietary nitrate modulates endothelial function through the attenuation of inflammatory responses and may be of potential therapeutic benefit in patients with established CAD.

Funding Acknowledgement

Type of funding sources: None.

Nanoparticles Modified With Cationic Thiol Surfactant as Efficient Inhibitors for the Corrosion of Carbon Steel

In this work, we report synthesis, characterization and corrosion inhibition properties of cationic thiol surfactant-capped silver (SC-Ag-NPs) and gold (SC-Au-NPs) nanoparticles. SC-Ag-NPs and SC-Au-NPs were characterized using regular techniques include TEM. Corrosion study was carried out using carbon steel (CS) in 3.5% NaCl aqueous solution and characterized using multiple electrochemical techniques. Our results suggest that the paint containing SC-Ag-NPs and SC-Au-NPs endow efficient corrosion protection to the CS. Especially, SC-Au-NPs based paint form a stronger barrier between the metal and the corrosive ions, leading to better inhibition properties.

HepatoScore-14: Measures of Biological Heterogeneity Significantly Improve Prediction of Hepatocellular Carcinoma Risk

BACKGROUND AND AIMS

Therapeutic, clinical trial entry and stratification decisions for hepatocellular carcinoma (HCC) are made based on prognostic assessments, using clinical staging systems based on small numbers of empirically selected variables that insufficiently account for differences in biological characteristics of individual patients' disease.

APPROACH AND RESULTS

We propose an approach for constructing risk scores from circulating biomarkers that produce a global biological characterization of individual patient's disease. Plasma samples were collected prospectively from 767 patients with HCC and 200 controls, and 317 proteins were quantified in a Clinical Laboratory Improvement Amendments-certified biomarker testing laboratory. We constructed a circulating biomarker aberration score for each patient, a score between 0 and 1 that measures the degree of aberration of his or her biomarker panel relative to normal, which we call HepatoScore. We used log-rank tests to assess its ability to substratify patients within existing staging systems/prognostic factors. To enhance clinical application, we constructed a single-sample score, HepatoScore-14, which requires only a subset of 14 representative proteins encompassing the global biological effects. Patients with HCC were split into three distinct groups (low, medium, and high HepatoScore) with vastly different prognoses (medial overall survival 38.2/18.3/7.1 months; P < 0.0001). Furthermore, HepatoScore accurately substratified patients within levels of existing prognostic factors and staging systems (P < 0.0001 for nearly all), providing substantial and sometimes dramatic refinement of expected patient outcomes with strong therapeutic implications. These results were recapitulated by HepatoScore-14, rigorously validated in repeated training/test splits, concordant across Myriad RBM (Austin, TX) and enzyme-linked immunosorbent assay kits, and established as an independent prognostic factor.

CONCLUSIONS

HepatoScore-14 augments existing HCC staging systems, dramatically refining patient prognostic assessments and therapeutic decision making and enrollment in clinical trials. The underlying strategy provides a global biological characterization of disease, and can be applied broadly to other disease settings and biological media.

Clinically Applicable Machine Learning Approaches to Identify Attributes of Chronic Kidney Disease (CKD) for Use in Low-Cost Diagnostic Screening

OBJECTIVE

Chronic kidney disease (CKD) is a major public health concern worldwide. High costs of late-stage diagnosis and insufficient testing facilities can contribute to high morbidity and mortality rates in CKD patients, particularly in less developed countries. Thus, early diagnosis aided by vital parameter analytics using affordable computer-aided diagnosis could not only reduce diagnosis costs but improve patient management and outcomes.

METHODS

In this study, we developed machine learning models using selective key pathological categories to identify clinical test attributes that will aid in accurate early diagnosis of CKD. Such an approach will save time and costs for diagnostic screening. We have also evaluated the performance of several classifiers with k-fold cross-validation on optimized datasets derived using these selected clinical test attributes.

RESULTS

Our results suggest that the optimized datasets with important attributes perform well in diagnosis of CKD using our proposed machine learning models. Furthermore, we evaluated clinical test attributes based on urine and blood tests along with clinical parameters that have low costs of acquisition. The predictive models with the optimized and pathologically categorized attributes set yielded high levels of CKD diagnosis accuracy with random forest (RF) classifier being the best performing.

CONCLUSIONS

Our machine learning approach has yielded effective predictive analytics for CKD screening which can be developed as a resource to facilitate improved CKD screening for enhanced and timely treatment plans.

Perspectives on natural compounds in chemoprevention and treatment of cancer: an update with new promising compounds

Cancer is the second deadliest disease worldwide. Although recent advances applying precision treatments with targeted (molecular and immune) agents are promising, the histological and molecular heterogeneity of cancer cells and huge mutational burdens (intrinsic or acquired after therapy) leading to drug resistance and treatment failure are posing continuous challenges. These recent advances do not negate the need for alternative approaches such as chemoprevention, the pharmacological approach to reverse, suppress or prevent the initial phases of carcinogenesis or the progression of premalignant cells to invasive disease by using non-toxic agents. Although data are limited, the success of several clinical trials in preventing cancer in high-risk populations suggests that chemoprevention is a rational, appealing and viable strategy to prevent carcinogenesis. Particularly among higher-risk groups, the use of safe, non-toxic agents is the utmost consideration because these individuals have not yet developed invasive disease. Natural dietary compounds present in fruits, vegetables and spices are especially attractive for chemoprevention and treatment because of their easy availability, high margin of safety, relatively low cost and widespread human consumption. Hundreds of such compounds have been widely investigated for chemoprevention and treatment in the last few decades. Previously, we reviewed the most widely studied natural compounds and their molecular mechanisms, which were highly exploited by the cancer research community. In the time since our initial review, many promising new compounds have been identified. In this review, we critically review these promising new natural compounds, their molecular targets and mechanisms of anticancer activity that may create novel opportunities for further design and conduct of preclinical and clinical studies.

Insulin-like growth factor 1/Child-Turcotte-Pugh composite score as a predictor of treatment outcomes in patients with advanced hepatocellular carcinoma treated with sorafenib

Background: Sorafenib was the first systemic therapy approved for the treatment of Child-Turcotte-Pugh (CTP) class A patients with advanced hepatocellular carcinoma (HCC). However, there are no biomarkers to predict survival and treatment outcomes and guide HCC systemic therapy. Type 1 insulin-like growth factor (IGF-1)/CTP composite score has emerged as a potential hepatic reserve assessment tool. Our study investigated the association of the IGF/CTP score with overall survival (OS) and progression-free survival (PFS) of HCC patients treated with sorafenib.

Materials and Methods: In this prospective study, patients with HCC were treated with sorafenib and followed up until progression/death. We calculated the IGF/CTP score and used the Kaplan-Meier method and log-rank test to estimate and compare the time-to-event outcomes between patient subgroups.

Results: 171 patients were included, 116 of whom were CTP class A. Median PFS for IGF/CTP score AA and AB patients were 6.88 and 4.28 months, respectively (p = 0.1359). Median OS for IGF/CTP score AA and AB patients were 14.54 and 7.60 months, respectively (p = 0.1378). The PFS and OS was superior in AA patients, but the difference was not significant, likely due to the sample size. However, there was a significant difference in early OS and PFS curves between AA and AB (p = 0.0383 and p = 0.0099), respectively.

Conclusions: In CTP class A patients, IGF/CTP score B was associated with shorter PFS and OS, however, study was underpowered to reach statistical significance. If validated in larger cohorts, IGF/CTP score may serve as stratification tool in clinical trials, a hepatic reserve assessment tool for HCC outcomes prediction and to assist in therapy decisions.

Impact of Integrating Insulin-Like Growth Factor 1 Levels into Model for End-Stage Liver Disease Score for Survival Prediction in Hepatocellular Carcinoma Patients

BACKGROUND

Liver reserve affects survival in hepatocellular carcinoma (HCC). Model for End-Stage Liver Disease (MELD) score is used to predict overall survival (OS) and to prioritize HCC patients on the transplantation waiting list, but more accurate models are needed. We hypothesized that integrating insulin-like growth factor 1 (IGF-1) levels into MELD score (MELD-IGF-1) improves OS prediction as compared to MELD.

METHODS

We measured plasma IGF-1 levels in training (n = 310) and validation (n = 155) HCC cohorts and created MELD-IGF-1 score. Cox models were used to determine the association of MELD and MELD-IGF-1 with OS. Harrell's c-index was used to compare the predictive capacity.

RESULTS

IGF-1 was significantly associated with OS in both cohorts. Patients with an IGF-1 level of ≤26 ng/mL in the training cohort and in the validation cohorts had significantly higher hazard ratios than patients with the same MELD but IGF-1 >26 ng/mL. In both cohorts, MELD-IGF-1 scores had higher c-indices (0.60 and 0.66) than MELD scores (0.58 and 0.60) (p < 0.001 in both cohorts). Overall, 26% of training and 52.9% of validation cohort patients were reclassified into different risk groups by MELD-IGF-1 (p < 0.001).

CONCLUSIONS

After independent validation, the MELD-IGF-1 could be used to risk-stratify patients in clinical trials and for priority assignment for patients on liver transplantation waiting list.

Abstract 1907: Src-Met signaling confers apoptosis resistance to EGFR and PI3K co-targeting independently of AKT and ERK pathway activation in head and neck cancer

Purpose: Molecularly targeted agents will play a major role in the next generation of personalized cancer therapies. However, intrinsic and acquired resistance to targeted agents poses challenges to the success of such treatments. The purpose of the current study was to investigate the intrinsic resistance of head and neck cancer (HNC) cell lines to apoptosis induced by the combination of EGFR inhibitor erlotinib and PI3K inhibitor BKM120. Methods: In a panel of 10 malignant and 1 premalignant HNC cell lines, we evaluated cell growth inhibition (by SRB assay), IC50, combination index, dose reduction index (by CalcuSyn Software), and apoptosis (by Annexin-V staining). Protein expression levels were measured by Western blotting. Small molecule inhibitors and siRNA-mediated knockdown strategies were used to inactivate and shut down the expression of the relevant proteins, respectively. Results: We have reported previously that single targeting of EGFR with erlotinib or PI3K with BKM120 (pan-PI3K inhibitor) suppressed cellular growth without inducing significant apoptosis. Co-targeting EGFR and PI3K demonstrated in vitro synergy in all except the JHU022 cell line and more effectively inhibited HNC xenograft growth in vivo. The combination of erlotinib and BKM120 induced variable apoptosis: some cell lines were very sensitive (MDA686TU, MDA686LN, 93-VU-147T), some moderately (Fadu, SqCCy1, MDA1483, UPCI:SCC090) and others were resistant (UD-SCC2, MSK-LEUK1, JHU022) to apoptosis induction. We found that the resistant cell line JHU022 expressed very high levels of p-Met (Y1234/1235). Inhibition of Met with small molecule inhibitor crizotinib or siRNA rendered this cell line highly sensitive to apoptosis induced by the combination of erlotinib and BKM120. Although inhibition of hepatocyte growth factor (HGF), the only known ligand for Met, with soluble neutralization antibody had no effect on Met phosphorylation, inhibition of Src family kinases (SFK) with dasatinib abolished Met phosphorylation at Y1234/1235. Dasatinib also made this cell line sensitive to apoptosis. Ablation of c-Src with siRNA had similar effects on p-Met (Y1234/1235) and apoptosis. Interestingly, inhibition of Met had no effects on AKT and ERK phosphorylation, two critical downstream pathways of receptor tyrosine kinases including Met. Conclusions: Our results strongly suggest that co-targeting of EGFR and PI3K has synergistic activity, is effective in vivo, and induces apoptosis of some HNC cell lines. Some resistant cell lines express a high level of p-Met as a downstream target of SFK, which confers resistance of these cells to EGFR and PI3K co-targeting. Finally, Met confers apoptosis resistance independently of AKT and ERK pathway activation.

Citation Format: Abu S. Anisuzzaman, Abedul Haque, Zhuo G. Chen, Dong M. Shin, A.R.M. Ruhul Amin. Src-Met signaling confers apoptosis resistance to EGFR and PI3K co-targeting independently of AKT and ERK pathway activation in head and neck cancer [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 1907.

A Comparative Study Between 20% Mannitol and 3% Hypertonic Saline for Brain Oedema Reduction during Elective Brain Tumour Surgery

Cerebral oedema is an important manifestation of brain tumour. The significant reduction of cerebral oedema can show rapid improvement of the patients. Hypertonic saline solution and mannitol both are commonly used for this action. It is now time to choose the better one. This was a prospective randomized comparative study designed to evaluate the efficacy of 3% hypertonic saline (NaCl) in reduction of brain oedema during brain tumour surgery and compare it with that of 20% Mannitol. The study was conducted in the department of Anaesthesiology, Combined Military Hospital, Dhaka, Bangladesh from July 2016 to December 2016. A total number of 47 patients for brain tumour surgery were selected. After screening 40 patients were finalized. Then the patients were divided into 2 equal groups 20 patients in each. Patients of Group A received 3% hypertonic saline and Group B 20% mannitol. Uniform anaesthetic technique applied for all patients, fixed surgeon/group of surgeons carried out the surgery. Heart rate and noninvasive blood pressure were monitored and kept with in ±20% baseline values different means. ETCO2 were kept in between 28-32mm of Hg by adjusting ventilator setting. Reduction of brain oedema was monitored by subjective assessment of surgeons using a 3 point scale of brain relaxation. The data were recorded in preformed data sheet. The results were tested by chi-square test to see their level of significance i.e. p value <0.05 was considered as significant. At the opening of dura, the number of brain conditions classified as soft, adequate and tight were statistically non-significant between groups. After 0.5 hour and 1.0 hour 10% patient's brain was tight in Group A whereas it was 35% and 40% in Group B respectively. Reduction of brain oedema or brain relaxation was significantly better in Group A compared to Group B (p<0.05). Urine output was higher with mannitol than hypertonic saline (p<0.05). Duration of ICU and hospital stay in both Group A and Group B were statistically similar (p>0.05). Compared to mannitol, hypertonic saline caused an increase in serum sodium concentration over time (p<0.05). From the available data, use of 20% mannitol and 3% hypertonic saline for brain oedema reduction, it is suggested that hypertonic saline significantly reduces the risk of tight brain and produce the brain more soft than mannitol during brain tumour surgery.

Perioperative intravenous contrast administration and the incidence of acute kidney injury after major gastrointestinal surgery: prospective, multicentre cohort study

BACKGROUND

This study aimed to determine the impact of preoperative exposure to intravenous contrast for CT and the risk of developing postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery.

METHODS

This prospective, multicentre cohort study included adults undergoing gastrointestinal resection, stoma reversal or liver resection. Both elective and emergency procedures were included. Preoperative exposure to intravenous contrast was defined as exposure to contrast administered for the purposes of CT up to 7 days before surgery. The primary endpoint was the rate of AKI within 7 days. Propensity score-matched models were adjusted for patient, disease and operative variables. In a sensitivity analysis, a propensity score-matched model explored the association between preoperative exposure to contrast and AKI in the first 48 h after surgery.

RESULTS

A total of 5378 patients were included across 173 centres. Overall, 1249 patients (23·2 per cent) received intravenous contrast. The overall rate of AKI within 7 days of surgery was 13·4 per cent (718 of 5378). In the propensity score-matched model, preoperative exposure to contrast was not associated with AKI within 7 days (odds ratio (OR) 0·95, 95 per cent c.i. 0·73 to 1·21; P = 0·669). The sensitivity analysis showed no association between preoperative contrast administration and AKI within 48 h after operation (OR 1·09, 0·84 to 1·41; P = 0·498).

CONCLUSION

There was no association between preoperative intravenous contrast administered for CT up to 7 days before surgery and postoperative AKI. Risk of contrast-induced nephropathy should not be used as a reason to avoid contrast-enhanced CT.

SAT0234 SERUM AXL, FERRITIN, IGFBP4 AND STNFR2 AS BIOMARKERS OF PEDIATRIC SLE

Background:

Proteomic screening is an efficient approach for identifying protein biomarkers in various inflammatory diseases. Our preliminary proteomic analysis revealed elevated levels of serum Axl, Ferritin, IGFBP4 and sTNFR2 in adult patients with active lupus nephritis (LN) (1). However, the role of these serum biomarkers in pediatric systemic lupus erythematosus (SLE) patients has not been examined.

Objectives:

To evaluate the performance of 4 serum protein markers for detecting disease activity in pediatric patients with SLE.

Methods:

83 pediatric patients who fulfilled ≥4 ACR criteria for SLE and 25 healthy controls were recruited for serological testing of 4 protein markers identified by antibody-coated microarray screen, namely Axl, ferritin, IGFBP4 and sTNFR2. SLE disease activity was assessed using the SLEDAI-2k score, renal disease activity was assessed by the renal SLEDAI (range 0-16; 0= inactive LN, ≥ 8= active renal). 57 patients had clinically active SLE (SLEDAI score ≥ 4 or having a flare) (28 active renal and 29 active non-renal SLE patients). In active renal patients, concurrent renal biopsy was performed, unless contraindicated. The ISN/RPS criteria were used to assess the histopathologic features of LN. Those Patients were further subcategorized into 2 groups; active proliferative (ISN/RPS classes III/IV) and non-proliferative (classes I/II/V).

Results:

The serum concentrations of Axl and ferritin were significantly higher in patients with active SLE than inactive SLE (3765±235 vs. 2513±130 pg/ml,P= 0.001) and (111±26 vs. 18±4 ng/ml,P =0.0001) respectively. Serum Axl levels were significantly higher in active renal versus active non-renal SLE patients (3765±235.3 vs. 2825±200.7 pg/ml,P= 0.04). In the active renal patients with paired kidney tissue and blood samples, none of the biomarkers tested discriminated classes of LN, although serum Axl, ferritin and IGBPB4 levels were higher in the proliferative subgroup. The levels of Axl, ferritin and IGFBP4 correlated significantly with SLEDAI scores (Axl, r= 0.58,P<0.0001; ferritin, r= 0.53,P<0.0001; IGFBP4, r= 0.229,P= 0.03). However, only serum Axl levels correlated significantly with the renal SLEDAI (r= 0.46,P= 0.01). The levels of Axl, IFGBP4 and sTNFR2 correlated with decreased C3 levels (r= - 0.54,P<0.0001; r= - 0.29,P= 0.007; r= - 0.29,P= 0.007) respectively. Only serum Axl and ferritin correlated with urinary PCR (r= 0.42,P<0.0001; r= 0.22,P=0.04) respectively. These markers were more specific, but less sensitive, in detecting concurrent SLE activity than elevated anti-dsDNA or decreased C3. The specificity values of serum ferritin and IGFBP4 for concurrent active lupus nephritis were higher than anti-dsDNA or C3. Serum ferritin was the best predictor of global SLE activity (AUC 0.81,P<0.0001), followed by C3 (AUC 0.79,P<0.0001) then Axl (AUC 0.71,P= 0.002), while both Axl and C3 were the best predictors of lupus nephritis activity (AUC 0.72, both).

Conclusion:

In pediatric SLE patients, serum ferritin and Axl perform better than traditional yardsticks in identifying disease activity, either global or renal. The performance of these serum markers should be explored further in a longitudinal cohort of pediatric SLE patients.

References:

[1]Wu T, Ding H, Han J, et al. Antibody-Array-Based Proteomic Screening of Serum Markers in Systemic Lupus Erythematosus: A Discovery Study. J Proteome Res. 2016 Jul 1;15 (7): 2102-14.

Disclosure of Interests:

None declared

Molecular Profiling of Hepatocellular Carcinoma Using Circulating Cell-Free DNA

PURPOSE

Molecular profiling has been used to select patients for targeted therapy and determine prognosis. Noninvasive strategies are critical to hepatocellular carcinoma (HCC) given the challenge of obtaining liver tissue biopsies.

EXPERIMENTAL DESIGN

We analyzed blood samples from 206 patients with HCC using comprehensive genomic testing (Guardant Health) of circulating tumor DNA (ctDNA).

RESULTS

A total of 153/206 (74.3%) were men; median age, 62 years (range, 18-91 years). A total of 181/206 patients had ≥1 alteration. The total number of alterations was 680 (nonunique); median number of alterations/patient was three (range, 1-13); median mutant allele frequency (% cfDNA), 0.49% (range, 0.06%-55.03%). TP53 was the common altered gene [>120 alterations (non-unique)] followed by EGFR, MET, ARID1A, MYC, NF1, BRAF, and ERBB2 [20-38 alterations (nonunique)/gene]. Of the patients with alterations, 56.9% (103/181) had ≥1 actionable alterations, most commonly in MYC, EGFR, ERBB2, BRAF, CCNE1, MET, PIK3CA, ARID1A, CDK6, and KRAS. In these genes, amplifications occurred more frequently than mutations. Hepatitis B (HBV)-positive patients were more likely to have ERBB2 alterations, 35.7% (5/14) versus 8.8% HBV-negative (P = 0.04).

CONCLUSIONS

This study represents the first large-scale analysis of blood-derived ctDNA in HCC in United States. The genomic distinction based on HCC risk factors and the high percentage of potentially actionable genomic alterations suggests potential clinical utility for this technology.

Dual inhibition of IGF-IR and ALK as an effective strategy to eradicate NPM-ALK+ T-cell lymphoma

Background

Nucleophosmin-anaplastic lymphoma kinase-expressing (NPM-ALK⁺) T cell lymphoma is an aggressive neoplasm. NPM-ALK, an oncogenic tyrosine kinase, plays a critical role in this lymphoma. Recently, selective ALK inhibitors have emerged as a first-line therapy for this neoplasm. Unfortunately, ALK inhibitors were hindered by emergence of resistance and relapse. We have previously demonstrated that type I insulin-like growth factor receptor (IGF-IR) is commonly expressed and activated in this lymphoma. In addition, IGF-IR and NPM-ALK are physically associated and reciprocally enhance their phosphorylation/activation. Herein, we tested the hypothesis that combined inhibition of IGF-IR and NPM-ALK could significantly improve the effects of inhibiting each kinase alone.

Methods

We used clinically utilized inhibitors of IGF-IR (picropodophyllin; PPP) and ALK (ASP3026) to assess the in vitro cellular effects of combined treatment versus treatment using a single agent. Moreover, we used a systemic NPM-ALK⁺ T cell lymphoma mouse model to analyze the in vivo effects of PPP and ASP3026 alone or in combination.

Results

Our data show that combined treatment with PPP and ASP3026 decreased the viability, proliferation, and anchorage-independent colony formation, and increased apoptosis of NPM-ALK⁺ T cell lymphoma cells in vitro. The in vitro effects of combined treatment were synergistic and significantly more pronounced than the effects of PPP or ASP3026 alone. Biochemically, simultaneous antagonism of IGF-IR and ALK induced more pronounced decrease in pIGF-IR^Y1135/1136, pNPM-ALK^Y646, and pSTAT3^Y705 levels than antagonizing IGF-IR or ALK alone. Moreover, combined targeting of IGF-IR and NPM-ALK decreased significantly systemic lymphoma tumor growth and improved mice survival in vivo. Consistent with the in vitro results, the in vivo effects of the combined therapy were more pronounced than the effects of targeting IGF-IR or ALK alone.

Conclusions

Combined targeting of IGF-IR and ALK is more effective than targeting IGF-IR or ALK alone in NPM-ALK⁺ T cell lymphoma. This strategy might also limit emergence of resistance to high doses of ALK inhibitors. Therefore, it could represent a successful therapeutic approach to eradicate this aggressive lymphoma. Importantly, combined inhibition is feasible because of the clinical availability of IGF-IR and ALK inhibitors. Our findings are applicable to other types of cancer where IGF-IR and ALK are simultaneously expressed.

Electronic supplementary material

The online version of this article (10.1186/s13045-019-0768-8) contains supplementary material, which is available to authorized users.

Abstract 706: A natural inhibitor of c-Met that sensitizes head and neck cancer cells resistant to EGFR and PI3K co-targeting

Purpose: Molecularly targeted agents will play a major role in the next generation of personalized cancer therapies. However, intrinsic and acquired resistance to targeted agents poses challenges to the success of such treatments. The Cancer Genome Atlas data suggest that both EGFR and PI3K pathways are reasonable targets in head and neck cancers (HNC). However, single agent treatment with EGFR inhibitor erlotinib or pan-PI3K inhibitor BKM120 fails to induce apoptosis of most HNC cell lines. We have previously reported that EGFR and PI3K co-targeting has synergistic antitumor effects both in vitro and in vivo and induces variable apoptosis. The purpose of the current study was to investigate the mechanism of intrinsic resistance to apoptosis induced by the combination of EGFR inhibitor erlotinib and PI3K inhibitor BKM120 and to sensitize the resistant cells with natural extracts.

Methods: In a panel of 10 malignant and 1 premalignant HNC cell lines, we evaluated apoptosis by Annexin-V staining. Protein expression levels were measured by Western blotting. Small molecule chemical inhibitors and siRNA-mediated knockdown strategies were used to inactivate and shut down the expression of the relevant proteins, respectively.

Results: The combination of erlotinib and BKM120 induced variable apoptosis. Some cell lines were very sensitive (Tu686, 686LN, 93-VU-147T), some were moderately sensitive (Fadu, SqCCy1, 1483, UMSSC90), and others were resistant (UD-SCC2, MSK-LEUK1, JHU022) to apoptosis induction. JHU022 and 1483 cell lines expressed very high levels of phosphorylated c-Met. Targeting c-Met with the small molecule inhibitor crizotinib or siRNA rendered these cell lines highly sensitive to erlotinib and BKM120 induced apoptosis. Moreover, inhibition of Src family kinases (SFK) with the small molecule inhibitor dasatinib or with c-Src-specific siRNA inhibited phosphorylated c-Met. In addition, inhibition of SFK in these cell lines conferred sensitivity to erlotinib and BKM120 induced apoptosis. We also screened several natural extracts isolated from microorganisms. We found that ACM, one of these extracts, strongly induced apoptosis of the resistant cell lines. Moreover, the extract inhibited constitutively active p-Met in the resistant cell line.

Conclusions: Our results strongly suggest that some of the resistant cell lines expressed high levels of phosphorylated c-Met downstream of SFK. This confers resistance of these cells to the combination of erlotinib and BKM120 as inhibition of this pathway sensitizes the cells. Moreover, the bacterial extract ACM is a natural inhibitor of c-Met which sensitizes these resistant cell lines. It may be an excellent direction for further drug development.

Citation Format: Asm Anisuzzaman, Abedul Haque, Brian Butler, ARM R. AMIN. A natural inhibitor of c-Met that sensitizes head and neck cancer cells resistant to EGFR and PI3K co-targeting [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 706.

Autotaxin determines colitis severity in mice and is secreted by B cells in the colon

Autotaxin (ATX or ENPP2) is a secreted lysophospholipase D that produces lysophosphatidic acid (LPA), a pleiotropic lipid mediator acting on specific GPCRs. ATX and LPA have been implicated in key (patho)physiologic processes, including embryonic development, lymphocyte homing, inflammation, and cancer progression. Using LPA receptor knockout mice, we previously uncovered a role for LPA signaling in promoting colitis and colorectal cancer. Here, we examined the role of ATX in experimental colitis through inducible deletion of Enpp2 in adult mice. ATX expression was increased upon induction of colitis, whereas ATX deletion reduced the severity of inflammation in both acute and chronic colitis, accompanied by transient weight loss. ATX expression in lymphocytes was strongly reduced in Rag1-/- and μMT mice, suggesting B cells as a major ATX-producing source, which was validated by immunofluorescence and biochemical analyses. ATX secretion by B cells from control, but not Enpp2 knockout, mice led to ERK activation in colorectal cancer cells and promoted T cell migration. We conclude that ATX deletion suppresses experimental colitis and that B cells are a major source of ATX in the colon. Our study suggests that pharmacological inhibition of ATX could be a therapeutic strategy in colitis.-Lin, S., Haque, A., Raeman, R., Guo, L., He, P., Denning, T. L., El-Rayes, B., Moolenaar, W. H., Yun, C. C. Autotaxin determines colitis severity in mice and is secreted by B cells in the colon.

Direct conversion of carbon nanofibers and nanotubes into diamond nanofibers and the subsequent growth of large-sized diamonds

We report a pulsed laser annealing method to convert carbon fibers and nanotubes into diamond fibers at ambient temperature and pressure in air. The conversion of carbon nanofibers and nanotubes into diamond nanofibers involves melting in a super undercooled state using nanosecond laser pulses, and quenching rapidly to convert into phase-pure diamond. The conversion process occurs at ambient temperature and pressure, and can be carried out in air. The structure of diamond fibers has been confirmed by selected-area electron diffraction in transmission electron microscopy, electron-back-scatter-diffraction in high-resolution scanning electron microscopy, all showing characteristic diffraction lines for the diamond structure. The bonding characteristics were determined by Raman spectroscopy with a strong peak near 1332 cm-1, and high-resolution electron-energy-loss spectroscopy in transmission electron microscopy with a characteristic peak at 292 eV for σ* for sp3 bonding and the absence of π* for sp2 bonding. The Raman peak at 1332 cm-1 downshifts to 1321 cm-1 for diamond nanofibers due to the phonon confinement in nanodiamonds. These laser-treated carbon fibers with diamond seeds are used to grow larger diamond crystallites further by using standard hot-filament chemical vapor deposition (HFCVD). We compare these results with those obtained without laser treating the carbon fibers. The details of diamond conversion and HFCVD growth are presented in this paper.

Inhibition of autotaxin alleviates inflammation and increases the expression of sodium-dependent glucose cotransporter 1 and Na+/H+ exchanger 3 in SAMP1/Fc mice

Crohn's disease (CD) is a chronic, relapsing, inflammatory disease that is often associated with malnutrition because of inflammation in the small intestine. Autotaxin (ATX) is a secreted enzyme that produces extracellular lysophosphatidic acid. Increasing evidence suggests that ATX is upregulated during inflammation, and inhibition of ATX has been effective in attenuating chronic inflammatory conditions, such as arthritis and pulmonary fibrosis. This study aims to determine whether inhibition of ATX alleviates CD-associated inflammation and malnutrition by using SAMP1/Fc mice, a model of CD-like ileitis. SAMP1/Fc mice were treated the ATX inhibitor PF-8380 for 4 wk. Inhibition of ATX led to increased weight gain in SAMP1/Fc mice, decreased T helper 2 cytokine expression, including IL-4, IL-5, and IL-13, and attenuated immune cell migration. SAMP1/Fc mice have low expression of Na⁺-dependent glucose transporter 1 (SGLT1), suggesting impaired nutrient absorption associated with ileitis. PF-8380 treatment significantly enhanced SGLT1 expression in SAMP1/Fc mice, which could reflect the increased weight changes. However, IL-4 or IL-13 did not alter SGLT1 expression in Caco-2 cells, ruling out their direct effects on SGLT1 expression. Immunofluorescence analysis showed that the expression of sucrase-isomaltase, a marker for intestinal epithelial cell (IEC) differentiation, was decreased in inflamed regions of SAMP1/Fc mice, which was partially restored by PF-8380. Moreover, expression of Na⁺/H⁺ exchanger 3 was also improved by PF-8380, suggesting that suppression of inflammation by PF-8380 enhanced IEC differentiation. Our study therefore suggests that ATX is a potential target for treating intestinal inflammation and restoration of the absorptive function of the intestine. NEW & NOTEWORTHY This study is the first, to our knowledge, to determine whether autotoxin (ATX) inhibition improves inflammation and body weights in SAMP1/Fc mice, a mouse model of ileitis. ATX inhibition increased body weights of SAMP1/Fc mice and increased Na⁺-dependent glucose transporter 1 (SGLT1) expression. Increased SGLT1 expression in the inflamed regions was not a direct effect of cytokines but an indirect effect of increased epithelial cell differentiation upon ATX inhibition.

Perineal closure following extralevator abdominoperineal excision for cancer of the rectum

AIM

Extralevator abdominoperineal resection (ELAPE) may be complicated by perineal wound healing problems and herniation. We report a consecutive series of 38 such patients with selective use of a fasciocutaneous V-Y buttock advancement flap (BAF).

METHOD

Data were collected on a series of patients undergoing ELAPE for rectal malignancy between August 2011 and July 2017. Demographics, management and outcomes were recorded prospectively. Perineal wound problems were considered as 'major' if they required packing; otherwise, they were classed as 'minor'.

RESULTS

Thirty-eight patients [eight female and 30 male; median age 63 (range: 35-89) years] underwent ELAPE. Thirty-seven had an adenocarcinoma of the rectum and one had a malignant melanoma. The median tumour height (from the anal verge) was 30 (range: 0-80) mm. Sixteen patients had a BAF. The median length of stay was 10 (range: 6-25) days. Primary perineal healing occurred in 18 (47%) patients. Major wound breakdown occurred in three (10%) patients and minor wound breakdown in 17 (45%). Two of the 16 patients having a BAF had major wound breakdown: one wound took 9 weeks to heal completely and the other took 9 months. Of the 22 patients who did not have a BAF, one had a major wound breakdown which closed by 3 months. There were no perineal fistulae or chronic sinuses. There were two perineal herniae that were successfully repaired by perineal insertion of biological mesh (Permacol™; Covidien, Dublin, Ireland).

CONCLUSIONS

Selective use of a BAF for perineal closure can give good results in terms of healing and an acceptably low early perineal herniation rate.

Comparative Study of Alginate and Omeprazole in Symptomatic Treatment of Non-erosive Gastroesophageal Reflux Disease

Gastroesophageal reflux disease is widely reported most prevalent disease of the gastrointestinal tract. The burden of gastroesophageal reflux disease (GERD) is increasing in Asia and the majority of patients have non-erosive reflux disease. This prospective, open label, non random (consecutive), experimental study was performed due to compare the therapeutic efficacy of alginate and omeprazole in relieving symptoms of non erosive reflux disease (NERD) and was carried out in the Outpatient Department of Gastroenterology, Dhaka Medical College Hospital, Dhaka, Bangladesh from December 2013 to May 2014. Sixty patients were enrolled for this study and were divided into two groups. Among them, 30 subjects were assigned to the omeprazole group (Group I) and 30 subjects to the alginate group (Group II). Omeprazole 20mg enteric coated capsule daily and alginate 10ml three times daily were administered 14 days in this study. In ITT analysis, achieving complete symptom relief (heart burn) was 56.7% in alginate group & 60% in omeprazole group. Statistically which was not significant (p=0.793). In PP analysis, this was 65.4% and 66.7% respectively. In this study, the overall satisfaction of omeprazole & alginate was more than 86% and the mean duration of heart burn free was found 5.0±4.0 days in Group I and 3.65±2.8 days in Group II. The difference was not statistically (p>0.05) significant between two groups in this study. Therapeutic efficacy and safety profiles of alginate were comparable to omeprazole after two weeks treatment in NERD subjects. So alginate may be considered as a relevant and effective alternative medication in non-erosive reflux.

Role of Liver Biopsy in the Diagnosis of Neonatal Cholestasis due to Biliary Atresia

Biliary atresia is the commonest cause of cholestatic jaundice. Early diagnosis & surgical correction helps long time survival & prevent development of cirrhosis. This study was conducted to find out the role of liver biopsy in the diagnosis of biliary atresia having positive hepatobiliary scintigraphy as there is chance of false positivity. This cross sectional study was carried out in Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, Bangladesh at Paediatric Gastroenterology & Nutrition Department from January 2014 to June 2015. All admitted patients with the diagnosis of neonatal cholestasis were evaluated clinically and by scintigraphy for biliary atresia. Having positive hepatobiliary scintigraphy but highly suggestive of biliary atresia were enrolled for this study. A total of 108 cases were initially selected. Among them 33 patients showed no excretion of tracer during hepatobiliary scintigraphy. Liver biopsy was done in these 33 cases. All cases (100%) had history of passage of pale or acholic stool. Fractionated serum bilirubin of >2mg/dl was found all of the cases. Histological scoring system reveals typical features of biliary atresia in 27(81.8%). Two had no conclusive histology of biliary atresia, four had features of neonatal hepatitis (12.1%). In this study, percutaneous liver biopsy with histological analysis by scoring system was found useful for the correct diagnosis of biliary atresia.

First characterization of immunogenic conjugates of Vi negative Salmonella Typhi O-specific polysaccharides with rEPA protein for vaccine development

Efficacious typhoid vaccines for young children will significantly reduce the disease burden in developing world. The Vi polysaccharide based conjugate vaccines (Vi-rEPA) against Salmonella Typhi Vi positive strains has shown high efficacy but may be ineffective against Vi negative S. Typhi. In this study, for the first time, we report the synthesis and evaluation of polysaccharide-protein conjugates of Vi negative S. Typhi as potential vaccine candidates. Four different conjugates were synthesized using recombinant exoprotein A of Pseudomonas aeruginosa (rEPA) and human serum albumin (HSA) as the carrier proteins, using either direct reductive amination or an intermediate linker molecule, adipic acid dihydrazide (ADH). Upon injection into mice, a significantly higher antibody titer was observed in mice administrated with conjugate-1 (OSP-HSA) (P=0.0001) and conjugate 2 (OSP-rEPA) (P≤0.0001) as compared to OSP alone. In contrast, the antibody titer elicited by conjugate 3 (OSPADH-HSA) and conjugate 4 (OSPADH-rEPA) were insignificant (P=0.1684 and P=0.3794, respectively). We conclude that reductive amination is the superior method to prepare the S. Typhi OSP glycoconjugate. Moreover, rEPA was a better carrier protein than HSA. Thus OSP-rEPA conjugate seems to be efficacious typhoid vaccines candidate, it may be evaluated further and recommended for the clinical trials.

IL-6 promotes CD4+ T-cell and B-cell activation during Plasmodium infection

Humoral immunity develops in the spleen during blood-stage Plasmodium infection. This elicits parasite-specific IgM and IgG, which control parasites and protect against malaria. Studies in mice have elucidated cells and molecules driving humoral immunity to Plasmodium, including CD4⁺ T cells, B cells, interleukin (IL)-21 and ICOS. IL-6, a cytokine readily detected in Plasmodium-infected mice and humans, is recognized in other systems as a driver of humoral immunity. Here, we examined the effect of infection-induced IL-6 on humoral immunity to Plasmodium. Using P. chabaudi chabaudi AS (PcAS) infection of wild-type and IL-6^-/- mice, we found that IL-6 helped to control parasites during primary infection. IL-6 promoted early production of parasite-specific IgM but not IgG. Notably, splenic CD138⁺ plasmablast development was more dependent on IL-6 than germinal centre (GC) B-cell differentiation. IL-6 also promoted ICOS expression by CD4⁺ T cells, as well as their localization close to splenic B cells, but was not required for early Tfh-cell development. Finally, IL-6 promoted parasite control, IgM and IgG production, GC B-cell development and ICOS expression by Tfh cells in a second model, Py17XNL infection. IL-6 promotes CD4⁺ T-cell activation and B-cell responses during blood-stage Plasmodium infection, which encourages parasite-specific antibody production.

Abstract 4097: Src-met signaling confers apoptosis resistance to the combination of BKM120 and erlotinib in head and neck cancer

Purpose: Molecularly targeted agents will play a major role in the next generation of personalized cancer therapies. However, intrinsic and acquired resistance to targeted agents poses challenges to the success of such treatments. The purpose of the current study was to investigate the intrinsic resistance of head and neck cancer (HNC) cell lines to apoptosis induced by the combination of EGFR inhibitor erlotinib and PI3K inhibitor BKM120.

Methods: In a panel of 10 malignant and 1 premalignant HN cell lines, we evaluated cell growth inhibition (by SRB assay), IC50, combination index, dose reduction index (by CalcuSyn Software), and apoptosis (by Annexin-V staining). Protein expression levels were measured by Western blotting. Small molecule chemical inhibitors and siRNA-mediated knockdown strategies were used to inactivate and shut down the expression of the relevant proteins, respectively.

Results: Single targeting of EGFR with erlotinib or PI3K with BKM120 (pan-PI3K inhibitor) suppressed cellular growth without inducing significant apoptosis. Co-targeting EGFR and PI3K demonstrated in vitro synergy in all except one cell line (based on combination index and dose reduction index) and more effectively inhibited HNC xenograft growth in vivo. The combination of erlotinib and BKM120 induced variable apoptosis: some cell lines were very sensitive (Tu686, 686LN, 93-VU-147T), some moderately (Fadu, SqCCy1, 1483, UMSSC90) and others were resistant (UD-SCC2, MSK-LEUK1, JHU022) to apoptosis induction. JHU022 and 1483 cell lines expressed very high levels of p-cMet. Targeting cMet with the small molecule inhibitor crizotinib or siRNA rendered these cell lines highly sensitive to erlotinib and BKM120 induced apoptosis. Moreover, inhibition of Src family kinases with the small molecule inhibitor dasatinib or with c-Src-specific siRNA inhibited p-cMet. In addition, inhibition of SFK in these cell lines conferred sensitivity to erlotinib and BKM120 induced apoptosis.

Conclusions: Our results strongly suggest that co-targeting of EGFR and PI3K has synergistic activity, is effective in vivo, and induces apoptosis of some HNC cell lines. Two of the resistant cell lines express a high level of p-cMet as a downstream target of SFK, which confers resistance of these cells to the combination of erlotinib and BKM120.

Citation Format: A.R.M. Ruhul Amin, Abu Anisuzzaman, Abedul Haque, Zhuo Chen, Dong Shin. Src-met signaling confers apoptosis resistance to the combination of BKM120 and erlotinib in head and neck cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 4097. doi:10.1158/1538-7445.AM2017-4097

In Vitro and In Vivo Synergistic Antitumor Activity of the Combination of BKM120 and Erlotinib in Head and Neck Cancer: Mechanism of Apoptosis and Resistance

We previously reported that the EGFR-targeted inhibitor erlotinib induces G₁ arrest of squamous cell carcinoma of the head and neck (SCCHN) cell lines without inducing significant apoptosis. Large-scale genomic studies suggest that >50% of SCCHN cases have activation of PI3K pathways. This study investigated whether cotargeting of EGFR and PI3K has synergistic antitumor effects and apoptosis induction. We examined growth suppression, apoptosis, and signaling pathway modulation resulting from single and combined targeting of EGFR and PI3K with erlotinib and BKM120, respectively, in a panel of SCCHN cell lines and a xenograft model of SCCHN. In a panel of 12 cell lines, single targeting of EGFR with erlotinib or PI3K with BKM120 suppressed cellular growth without inducing significant apoptosis. Cotargeting of EGFR and PI3K synergistically inhibited SCCHN cell line and xenograft tumor growth, but induced variable apoptosis; some lines were highly sensitive, others were resistant. Mechanistic studies revealed that the combination inhibited both axes of the mTORC1 (S6 and 4EBP1) pathway in apoptosis-sensitive cell lines along with translational inhibition of Bcl-2, Bcl-xL, and Mcl-1, but failed to inhibit p-4EBP1, Bcl-2, Bcl-xL, and Mcl-1 in an apoptosis-resistant cell line. siRNA-mediated knockdown of eIF4E inhibited Bcl-2 and Mcl-1 and sensitized this cell line to apoptosis. Our results strongly suggest that cotargeting of EGFR and PI3K is synergistic and induces apoptosis of SCCHN cell lines by inhibiting both axes of the AKT-mTOR pathway and translational regulation of antiapoptotic Bcl-2 proteins. These findings may guide the development of clinical trials using this combination of agents. Mol Cancer Ther; 16(4); 729-38. ©2017 AACR.

Device-associated infections in a paediatric intensive care unit in Pakistan

This study assessed the effect of implementation of active infection control and surveillance on the occurrence of device-associated infections (DAIs) in a paediatric intensive care unit (PICU) from 2012 to 2015. There were 1378 patients, equating to 4632 patient-days, on the PICU, and 29 DAI episodes, giving an incidence rate of 2.1% and an incidence density rate of 6.26 per 1000 patient-days. The rates of central-line-associated bloodstream infections, ventilator-associated pneumonia and catheter-related urinary tract infections were 7/1000 central-line-days, 1.17/1000 ventilator-days and 0.24/1000 urinary-catheter-days, respectively. Despite the overall low rate of DAIs in the PICU, there was a relatively high rate of central-line-associated bloodstream infections.

Processable PMR-Type Polyimides: Process-Property Relationships, Curing Kinetics, and Thermooxidative Stability

The rheological and structural characteristics of polyimides with enhanced melt flow have been investigated. The polyimides were based on 2,3,3′,4′-biphenyltertracarboxylic dianhydride (PBDA) and a mixture of a diamine, 4,4′ (1,4-phenylene-bismethylene) bisaniline (BAX) and a triamine, 1,3,5-Tris (4-aminophenoxybenzene), TAB, where the amount of TAB was 4 and 8%. Melt viscosities of these polymers suggest that they are processable by resin infusion methods. Although curing occurs through the phenylethynyl endcap, the steric and electronic differences of the three amines results in different cure kinetics and heterogeneous crosslinking. This is manifested in multiple Tg values in the differential scanning calorimetry (DSC) scan of the cured samples. Rheological and DSC kinetic studies of the cure behavior indicate that the sample with 4% TAB cures more quickly than the system with 8% TAB and it has a lower activation energy (147 versus 185 kJ mole-1). Thermal gravimetric analysis (TGA) scans indicate that both TAB based samples are more thermally stable than PMR-15. The lower activation energy for 8% TAB, relative to 4% TAB (147.0 versus 170.2 kJ mole-1) suggests the additional branching present decreases the thermal stability.

Abstract 3502: Combination of BKM120 and erlotinib in squamous cell carcinoma of the head and neck: mechanism of in vitro and in vivo synergy

Purpose: Molecularly targeted agents will play a major role in the next generation of personalized cancer therapies. The EGFR-targeted monoclonal antibody cetuximab is currently the only FDA-approved targeted treatment for head and neck cancers (HNC) with a response rate of less than 15%. Recent large scale genomic studies including TCGA suggest that &gt;50% of HNC cases have activation of the PI3K/AKT/mTOR

pathways, suggesting PI3K as an excellent target for HNC. The purpose of the current study is to investigate whether co-targeting EGFR and PI3K has synergistic antitumor effects and to understand the mechanism of synergy.

Methods: In a panel of 10 malignant and 1 premalignant HN cell lines, we evaluated cell growth inhibition (by SRB assay); IC50, combination index, and dose reduction index (by CalcuSyn), and apoptosis (by Annexin-V staining). mRNA and protein expression were measured by qPCR and Western blotting, respectively. Small molecule chemical inhibitors and siRNA-mediated knockdown strategies were used to inactivate and shut down the expression of the relevant proteins, respectively.

Results: Single targeting of EGFR with erlotinib or PI3K with BKM120 (pan-PI3K inhibitor) suppressed cellular growth without inducing significant apoptosis. Co-targeting EGFR and PI3K had in vitro synergy in all except one cell line (based on combination index and dose reduction index) and more effectively inhibited HNC xenograft growth in vivo. The combination of erlotinib and BKM120 induced variable apoptosis: some cell lines were very sensitive (Tu686, 686LN, 93-VU-147T), some moderately (Fadu, SqCCy1, 1483, UMSSC90) and others were resistant (UD-SCC2, MSK-LEUK1, JHU022) to apoptosis induction. Only pan-PI3K inhibitors (BKM120 and BEZ235) induced effective apoptosis in combination with erlotinib, since the PI3K-α inhibitor BYL279 or allosteric mTORC1 inhibitor RAD001 failed to induce apoptosis in combination with erlotinib. Erlotinib strongly inhibited p-EGFR and p-ERK in vitro and in vivo, but only partially inhibited p-AKT. On the other hand, BKM120 completely inhibited p-AKT without affecting p-ERK. We also found that the combination of BKM120 and erlotinib strongly inhibited both axes of the AKT-mTORC1 pathway in sensitive cell lines, but failed to inhibit p-4EBP1 in one resistant cell line (UD-SCC2). In addition, the combination of BKM120 and erlotinib strongly inhibited Bcl-2, Bcl-xL and MCL-1 at the translational level in the sensitive cell lines but not the resistant one. siRNA-mediated knockdown of eIF4E (to inhibit 4EBP1-eIF4E-dependent translation) sensitized UD-SCC2 cells to the combination of erlotinib and BKM-induced apoptosis.

Conclusions: Our results strongly suggest that co-targeting of EGFR and PI3K is synergistic and induces apoptosis of HNC cell lines by inhibiting both axes of the AKT-mTOR pathway and translational regulation of anti-apoptotic Bcl-2 proteins.

Citation Format: Abu Anisuzzaman, Abedul Haque, Zhuo Chen, Dong M. Shin, A.R.M. Ruhul Amin. Combination of BKM120 and erlotinib in squamous cell carcinoma of the head and neck: mechanism of in vitro and in vivo synergy. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3502.

Mental Health Systems Development in UAE

Background

This paper examines the historical development of mental health services in the UAE including formation of federal laws associated with mental health and ministerial decrees. It also discusses cultural considerations in mental health practice in a society that is highly pluralistic and populated mainly by foreigners. The sharia aspects of mental health are also addressed.

Aims

The aims of the paper are to familiarize readers in above areas and encourage further work in the area of mental health in UAE.

Methods

The research is based on literature review.

Results

All federal laws and ministerial decrees are listed and local cultural considerations and sharia laws discussed, as they are unique to his country and region.

Conclusion

Although mental health is traditionally neglected in this country it is developing very fast and it is essential to keep track of and encourage such growth for the benefit of consumers and mental health professionals.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Combination of erlotinib and EGCG induces apoptosis of head and neck cancers through posttranscriptional regulation of Bim and Bcl-2

Combinatorial approaches using two or more compounds are gaining increasing attention for cancer therapy. We have previously reported that the combination of the EGFR-TKI erlotinib and epigallocatechin-3-gallate (EGCG) exhibited synergistic chemopreventive effects in head and neck cancers by inducing the expression of Bim, p21, p27, and by inhibiting the phosphorylation of ERK and AKT and expression of Bcl-2. In the current study, we further investigated the mechanism of regulation of Bim, Bcl-2, p21 and p27, and their role in apoptosis. shRNA-mediated silencing of Bim significantly inhibited apoptosis induced by the combination of erlotinib and EGCG (p = 0.005). On the other hand, overexpression of Bcl-2 markedly protected cells from apoptosis (p = 0.003), whereas overexpression of constitutively active AKT only minimally protected cells from apoptosis induced by the combination of the two compounds. Analysis of mRNA expression by RT-PCR revealed that erlotinib, EGCG and their combination had no significant effects on the mRNA expression of Bim, p21, p27 or Bcl-2 suggesting the post-transcriptional regulation of these molecules. Furthermore, we found that erlotinib or the combination of EGCG and erlotinib inhibited the phosphorylation of Bim and stabilized Bim after inhibition of protein translation by cycloheximide. Taken together, our results strongly suggest that the combination of erlotinib and EGCG induces apoptosis of SCCHN cells by regulating Bim and Bcl-2 at the posttranscriptional level.

Transfer of aflatoxins from naturally contaminated feed to milk of Nili-Ravi buffaloes fed a mycotoxin binder

The objectives of this study were to observe the extent of transfer of aflatoxin B1 in feed to the aflatoxin M1 metabolite in milk in Nili-Ravi buffaloes and to evaluate the efficacy of a commercial mycotoxin binder (Mycofix, Biomin Singapore) incorporated into feed to minimise this transfer. Multiparous animals (n = 28) were randomly distributed to four groups corresponding to two treatments each with two levels of aflatoxin B1. Individual animals were exposed to naturally contaminated feed providing a total of 1475 µg/day (Groups A and B) or 2950 µg/day (Groups C and D) of aflatoxin B1. Groups B and D were given 50 g of mycotoxin binder daily mixed with feed whereas Groups A and C were kept as controls. Feed samples were analysed by reverse phase high performance liquid chromatography for aflatoxin B1 and milk samples were evaluated by enzyme-linked immunosorbent assay for the liver metabolite aflatoxin M1. The mean value of total daily aflatoxin M1 excretion for animals fed 2950 µg/day of aflatoxin B1 (112.6 µg/day) was almost double (P < 0.001) than the excretion in buffaloes fed 1475 µg/day (62.2 µg/day). The mean daily concentration of aflatoxin M1 in milk of animals from both treatment groups supplemented with 50 g/day of mycotoxin binder was 76.5 µg/day, nearly 22 µg lower than those without binder at 98.3 µg/day (s.e.d. = 5.99: P < 0.01). The interaction of binder and treatment was not significant i.e. the 50 g/day of binder was able to sequester aflatoxin B1 with the same efficiency in groups fed with high and low concentrations of aflatoxin B1. Carry over was (3.44%) lower (P = 0.001) in animals supplemented with 50 g/day of mycotoxin binder than those fed no binder (4.60%). Thus buffaloes are highly efficient at transferring aflatoxins in feed to the aflatoxin M1 metabolite in milk, whereas mycotoxin binder is capable of alleviating without preventing this contamination risk.

Association between vasoactive-inotropic score and mortality in pediatric septic shock

OBJECTIVE

To assess the association between Vasoactive Inotrope Score (vis) and mortality in children with fluid-refractory septic shock.

METHODS

A retrospective chart review of 71 children (age 1 mo-16y) admitted with fluid-refractory septic shock in pediatric intensive care unit during a two year period was done. We divided our cohort into two groups viz High vasoactive inotrope score (Group-H) and Low-vasoactive inotrope score (Group-L) based on a cut-off value of 20.

RESULTS

73% of the children were in Group-L. The mortality rate was 44% and 100% in Group L and Group H, respectively.

CONCLUSIONS

High inotropic score in children with septic shock is associated with high mortality rate.

Preclinical In Vitro, In Vivo, and Pharmacokinetic Evaluations of FLLL12 for the Prevention and Treatment of Head and Neck Cancers

Despite its high promise for cancer prevention and therapy, the potential utility of curcumin in cancer is compromised by its low bioavailability and weak potency. The purpose of the current study was to assess the in vitro and in vivo efficacy and pharmacokinetic parameters of the potent curcumin analogue FLLL12 in SCCHN and identify the mechanisms of its antitumor effect. IC50 values against a panel of one premalignant and eight malignant head and neck cancer cell lines as well as apoptosis assay results suggested that FLLL12 is 10- to 24-fold more potent than natural curcumin depending on the cell line and induces mitochondria-mediated apoptosis. In vivo efficacy (xenograft) and pharmacokinetic studies also suggested that FLLL12 is significantly more potent and has more favorable pharmacokinetic properties than curcumin. FLLL12 strongly inhibited the expression of p-EGFR, EGFR, p-AKT, AKT, Bcl-2, and Bid and increased the expression of Bim. Overexpression of constitutively active AKT or Bcl-2 or ablation of Bim or Bid significantly inhibited FLLL12-induced apoptosis. Further mechanistic studies revealed that FLLL12 regulated EGFR and AKT at transcriptional levels, whereas Bcl-2 was regulated at the translational level. Finally, FLLL12 strongly inhibited the AKT downstream targets mTOR and FOXO1a and 3a. Taken together, our results strongly suggest that FLLL12 is a potent curcumin analogue with more favorable pharmacokinetic properties that induces apoptosis of head and neck cancer cell lines by inhibition of survival proteins including EGFR, AKT, and Bcl-2 and increasing of the proapoptotic protein Bim.

Abstract 29: Potent curcumin analog FLLL12 induces apoptosis in lung cancer cells through death receptor-5-dependent pathway

Background: Drug-associated toxicity is one of the major challenges in the management of cancer patients. Unlike chemotherapy drugs, the safety of natural compounds such as curcumin has been well established. However, the potential use of curcumin in cancer treatment has been compromised by its low bioavailability, limited tissue distribution, and rapid biotransformation leading to low efficacy. To circumvent these problems, more potent and bioavailable analogs have been synthesized. In the current study, we investigated the mechanism of anti-tumor effect of one such analog, FLLL12, in lung cancer cells.

Methods: A panel of premalignant and malignant lung cancer cell lines was used for the study. SRB assay was used to measure cell growth inhibition and IC50. Annexin-V staining was conducted for apoptosis assay. Expression of mRNAs and proteins were measured by RT-PCR and Western blotting, respectively. Small molecule chemical inhibitors and siRNA-mediated knockdown strategies were used to inactivate and shut down the expression of the relevant proteins, respectively.

Results: IC50 values (0.63-1.67 μM for FLLL12 as compared to 6.06-12.4 μM for curcumin, depending on the cell lines) and apoptosis results (annexin V staining and cleavage of PARP and caspase 3) suggest that FLLL12 is 5-10-fold more potent than curcumin against lung cancer cells. Moreover, FLLL12 induced the expression of death receptor-5 (DR5). Ablation of the expression of the components of the extrinsic apoptotic pathway (DR5, caspase 8 and BID) significantly protected cells from FLLL12-induced apoptosis as evidenced by reduced annexin V staining (p = 0.0008, p = 0.0001 and p = 0.0007 for DR5, caspase 8 and BID, respectively) and cleavage of PARP and caspase 3. Analysis of mRNA expression by RT-PCR revealed that FLLL-12 had no significant effect on the expression of DR5 mRNA. Interestingly, inhibition of global phosphatase activity by phosphatase inhibitor cocktail (PIC) completely abolished DR5 expression and significantly inhibited apoptosis (p = 0.0007 and p = 0.001, respectively) and the cleavage of casepase-3 and PARP. Similarly, inhibition of protein tyrosine phosphatases (PTPs) by sodium orthovanadate, but not by the alkaline phosphatase inhibitor imidazole, inhibited DR5 expression, apoptosis (p = 0.006) and cleavage of caspase-3 and PARP, suggesting the involvement of PTPs in the regulation of DR5 expression. FLLL12 also induced the expression of p53 and p73. However, inactivation of these proteins with their dominant negative construct or siRNA had no significant effects on apoptosis induction.

Conclusions: Our results strongly suggest that FLLL12 induces apoptosis of lung cancer cell lines by posttranscriptional regulation of DR5 through activation of protein tyrosine phosphatase(s). This study was supported by NCI R03 CA171663, NCI P50 CA128613 and Robbins Scholar Award of Winship Cancer Institute of Emory University.

Citation Format: Abedul Haque, Mohammad A. Rahman, James R. Fuchs, Zhuo G. Chen, Fadlo R. Khuri, Dong M. Shin, A.R.M. Ruhul Amin. Potent curcumin analog FLLL12 induces apoptosis in lung cancer cells through death receptor-5-dependent pathway. [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 29. doi:10.1158/1538-7445.AM2015-29

Modelling the increased frequency of extreme sea levels in the Ganges-Brahmaputra-Meghna delta due to sea level rise and other effects of climate change

Coastal flooding due to storm surge and high tides is a serious risk for inhabitants of the Ganges-Brahmaputra-Meghna (GBM) delta, as much of the land is close to sea level. Climate change could lead to large areas of land being subject to increased flooding, salinization and ultimate abandonment in West Bengal, India, and Bangladesh. IPCC 5th assessment modelling of sea level rise and estimates of subsidence rates from the EU IMPACT2C project suggest that sea level in the GBM delta region may rise by 0.63 to 0.88 m by 2090, with some studies suggesting this could be up to 0.5 m higher if potential substantial melting of the West Antarctic ice sheet is included. These sea level rise scenarios lead to increased frequency of high water coastal events. Any effect of climate change on the frequency and severity of storms can also have an effect on extreme sea levels. A shelf-sea model of the Bay of Bengal has been used to investigate how the combined effect of sea level rise and changes in other environmental conditions under climate change may alter the frequency of extreme sea level events for the period 1971 to 2099. The model was forced using atmospheric and oceanic boundary conditions derived from climate model projections and the future scenario increase in sea level was applied at its ocean boundary. The model results show an increased likelihood of extreme sea level events through the 21st century, with the frequency of events increasing greatly in the second half of the century: water levels that occurred at decadal time intervals under present-day model conditions occurred in most years by the middle of the 21st century and 3-15 times per year by 2100. The heights of the most extreme events tend to increase more in the first half of the century than the second. The modelled scenarios provide a case study of how sea level rise and other effects of climate change may combine to produce a greatly increased threat to life and property in the GBM delta by the end of this century.