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.

AR. 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 >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.