Improving combination therapies: targeting A2B-adenosine receptor to modulate metabolic tumor microenvironment and immunosuppression

BACKGROUND

We investigated the role of A2B-adenosine receptor in regulating immunosuppressive metabolic stress in the tumor microenvironment. Novel A2B-adenosine receptor antagonist PBF-1129 was tested for antitumor activity in mice and evaluated for safety and immunologic efficacy in a phase I clinical trial of patients with non-small cell lung cancer.

METHODS

The antitumor efficacy of A2B-adenosine receptor antagonists and their impact on the metabolic and immune tumor microenvironment were evaluated in lung, melanoma, colon, breast, and epidermal growth factor receptor-inducible transgenic cancer models. Employing electron paramagnetic resonance, we assessed changes in tumor microenvironment metabolic parameters, including pO2, pH, and inorganic phosphate, during tumor growth and evaluated the immunologic effects of PBF-1129, including its pharmacokinetics, safety, and toxicity, in patients with non-small cell lung cancer.

RESULTS

Levels of metabolic stress correlated with tumor growth, metastasis, and immunosuppression. Tumor interstitial inorganic phosphate emerged as a correlative and cumulative measure of tumor microenvironment stress and immunosuppression. A2B-adenosine receptor inhibition alleviated metabolic stress, downregulated expression of adenosine-generating ectonucleotidases, increased expression of adenosine deaminase, decreased tumor growth and metastasis, increased interferon γ production, and enhanced the efficacy of antitumor therapies following combination regimens in animal models (anti-programmed cell death 1 protein vs anti-programmed cell death 1 protein plus PBF-1129 treatment hazard ratio = 11.74 [95% confidence interval = 3.35 to 41.13], n = 10, P < .001, 2-sided F test). In patients with non-small cell lung cancer, PBF-1129 was well tolerated, with no dose-limiting toxicities; demonstrated pharmacologic efficacy; modulated the adenosine generation system; and improved antitumor immunity.

CONCLUSIONS

Data identify A2B-adenosine receptor as a valuable therapeutic target to modify metabolic and immune tumor microenvironment to reduce immunosuppression, enhance the efficacy of immunotherapies, and support clinical application of PBF-1129 in combination therapies.

Melanoma-derived mediators can foster the premetastatic niche: crossroad to lymphatic metastasis

The natural history of advanced malignant melanoma demonstrates that, in most cases, widespread tumor dissemination is preceded by regional metastases involving tumor-draining lymph nodes [sentinel lymph nodes (SLNs)]. Under physiological conditions, LNs play a central role in immunosurveillance to non-self-antigens to which they are exposed via afferent lymph. The dysfunctional immunity in SLNs is mediated by tumor secretory factors that allow the survival of metastatic melanoma cells within the LN by creating a premetastatic niche (PMN). Recent studies outline the altered microenvironment of LNs shaped by melanoma mediators. Here, we discuss tumor secretory factors involved in subverting tumor immunity and remodeling LNs and highlight emerging therapeutic strategies to reinvigorate antitumoral immunity in SLNs.

Abstract A021: Older adult-specific microbes correlate with treatment response and markers of T-cell senescence in NSCLC

This abstract is being presented as a short talk in the scientific program. A full abstract is available in the Short Talks from Proffered Abstracts section (PR004) of the Conference Proceedings.

Citation Format: Daniel Spakowicz, Rebecca Hoyd, Caroline E. Wheeler, Nyelia Williams, Amna Bibi, Marium Husain, Srichandhana Rajamouli, Shankar Suman, Joseph Amann, Madison Grogan, Pooja Vibhakar, Dwight H. Owen, David P. Carbone, Ashley Rosko, Christin E. Burd, Carolyn J. Presley. Older adult-specific microbes correlate with treatment response and markers of T-cell senescence in NSCLC [abstract]. In: Proceedings of the AACR Special Conference: Aging and Cancer; 2022 Nov 17-20; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2022;83(2 Suppl_1):Abstract nr A021.

Abstract PR004: Older adult-specific microbes correlate with treatment response and markers of T-cell senescence in NSCLC

The gut microbiome changes with age and affects many aspects of human health, including response to cancer treatments. Cancer survival rates have improved with new treatment options, including immune checkpoint blockade (ICB); however, the objective response rate remains low. Manipulation of the microbiome is a promising approach to improving cancer outcomes, but the effect of age is understudied. Here, we sought to understand whether (1) specific microbes are associated with treatment response in older adults with non-small cell lung cancer (NSCLC) and (2) whether these microbes are the same as for younger adults. Next, we explored the causal effects of the microbiome on ICB response in mouse models and the relationship with blood-based markers of T-cell senescence. We conducted a prospective cohort study of adults ≥60 years with a new diagnosis of NSCLC who received any treatment modality. Stool was collected, and metagenomic whole-genome shotgun sequencing was performed. Blood T-cells were isolated, the RNA purified and then assessed for markers of senescence by nanostring. Response to treatment was determined by RECIST v1.1 criteria. Generalized linear regression was used to relate baseline microbiome abundances to treatment response and non-parametric correlations associated with CDKN2A (p16) expression to microbe abundances. To assess the causal role of the gut microbiome in ICB response, we gavaged gut microbiome samples from responders and non-responders into C57BL/6 mice to create human-microbiome avatar models. The mice were then injected with MC38 cancer cells and treated with anti-PD1 or isotype control antibodies, and tumor volume was measured over time. Biospecimens and best response data at three months were captured from 23 patients, of which five had a complete response, eight had a partial response, eight had stable disease, and two had progressive disease. Over 50 microbes were associated with a response after p-value adjustment. Responder stool was enriched for microbes associated with youth and ICB response (Bifidobacterium adolescentis, p = 2.64e-20). However, microbial taxa associated with response differed from those reported in younger populations (Firmicutes sp. CAG 145, p = 1.58e-20, Oscillibacter sp. 57-20, p = 7.96e-24). Stool from non-responders (NRs) was enriched in taxa previously linked to treatment-related toxicities and shorter progression-free survival (Streptococcus lutetiensis, p = 4.55E-24) but also contained microbes previously linked to response in younger adults (e.g., Roseburia sp. CAG 309, p = 5.16e-15). The T cell senescence marker, p16, correlated with the most enriched taxon in non-responders NRs (Streptococcus thermophilus, r = 0.45, p = 0.02), suggesting a connection between immune aging and the microbiome. Preliminary fecal transplant studies in mice showed improved ICB response in mice engrafted with stool from responders versus non-responders. Together, these data identify potential differences in the gut microbiomes of young and older adult NSCLC patients who respond to ICB.

Citation Format: Daniel Spakowicz, Rebecca Hoyd, Caroline E. Wheeler, Nyelia Williams, Amna Bibi, Marium Husain, Srichandhana Rajamouli, Shankar Suman, Joseph Amann, Madison Grogan, Pooja Vibhakar, Dwight H. Owen, David P. Carbone, Ashley Rosko, Christin E. Burd, Carolyn J. Presley. Older adult-specific microbes correlate with treatment response and markers of T-cell senescence in NSCLC [abstract]. In: Proceedings of the AACR Special Conference: Aging and Cancer; 2022 Nov 17-20; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2022;83(2 Suppl_1):Abstract nr PR004.

Metabolic reprogramming by adenosine antagonism and implications in non-small cell lung cancer therapy

Non-small cell lung cancer (NSCLC) is a heterogeneous disease with genetic and environmental parameters that influence cell metabolism. Because of the complex interplay of environmental factors within the tumor microenvironment (TME) and the profound impact of these factors on the metabolic activities of tumor and immune cells, there is an emerging interest to advance the understanding of these diverse metabolic phenotypes in the TME. High levels of adenosine are characteristic of the TME, and adenosine can have a significant impact on both tumor cell growth and the immune response. Consistent with this, we showed in NSCLC data from TCGA that high expression of the A2BR leads to worse outcome and that expression of A2BR may be different for different mutation backgrounds. We then investigated the metabolic reprogramming of tumor cells and immune cells (T and dendritic cells) by adenosine. We used A2AR and A2BR antagonism or agonism as well as receptor knockout animals to explore whether these treatments altered specific immune compartments or conferred specific therapeutic vulnerabilities. Using the seahorse assay, we found that an A2BR antagonist modulates oxidative stress homeostasis in NSCLC cell lines. In addition, we found distinct metabolic roles of A2AR and A2BR receptors in T cell activation and dendritic cell maturation. These data suggest potential mechanisms and therapeutic benefits of A2 receptor antagonist therapy in NSCLC.

Abstract 3523: A Black Raspberry dietary intervention to modify the gut microbiome and improve the response to immune checkpoint inhibitors

Lung cancer kills more people annually worldwide than any other cancer. Outcomes have improved with the use of immune checkpoint inhibitor (ICI) treatment, however, only about 20% of tumors respond. Emerging data demonstrate that responses to ICI may depend on the host microbiome. The challenge is to identify strategies to manipulate the gut microbiome to improve response to ICIs. Here we explore a targeted dietary intervention to modify the microbiome and determine the response to ICIs. Studies in a preclinical murine model showed that freeze-dried black raspberry powder (AIN-76A synthetic diet containing 5% lyophilized black raspberry powder) increased the abundance of Akkermansia muciniphila, which has been associated with improved response to ICIs in melanoma. Next, we conducted a human intervention trial called the BEWELL Study (Black raspberry nEctar Working to prEvent Lung cancer NCT04267874). This placebo-controlled, randomized, cross-over trial examined the impact of 2x 80 mL black raspberry (BRB) nectar drink boxes per day for 4 weeks. There were 96 participants recruited and classified as being at high risk of developing lung cancer (eligibility criteria: &gt;30 pack-year smoking history and 55-77 years old) in an attempt to match the phenotype of typical lung cancer patients but allowing us to clearly assess the impact of the intervention on the microbiome. Pre- and post-dietary intervention gut microbiome, blood, and urine samples were collected. Black raspberry dietary supplementation was not associated with a significant change in A. muciniphila (logistic regression with negative binomial Wald test p-value 0.056), however, changes in other taxa were observed. Finally, stool from participants in the BEWELL study was gavaged into C57BL/6J mice to create human microbiome avatar models. Mouse colon cancer cells (mc38) were injected subcutaneously and treated with anti-PD1 Ab (5mg/kg mouse; clone RMP1-14) or isotype control (clone 2A3). Preliminary experiments using avatar mice with post-BRB human microbiomes showed smaller tumors relative to mice receiving stool from that same individual pre-BRB dietary intervention, relative to isotype control (t-test, p-value 0.05). These results suggest that black raspberry nectar may modify the human gut microbiome in a way that promotes an improved response to immunotherapy.

Citation Format: Amna Bibi, Aaditya Pallerla, Nyelia Williams, Caroline Wheeler, Rebecca Hoyd, Shankar Suman, Joseph Amann, Mounika Goruganthu, Tamio Okimoto, Yangyang Liu, Marisa Bittoni, Ni Shi, Shiqi Zhang, Alvin Anand, Kristen Heitman, Maxine Mendelson, Elizabeth M. Grainger, Madison Grogan, Carolyn J. Presley, Fred K. Tabung, Lang Li, Yael Vodovotz, Jiangjiang Zhu, David P. Carbone, Tong Chen, Steven K. Clinton, Daniel Spakowicz. A Black Raspberry dietary intervention to modify the gut microbiome and improve the response to immune checkpoint inhibitors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3523.

Abstract 1110: Targeting β-catenin enhances the therapeutic efficacy of osimertinib in EGFR- mutant non-small cell lung cancer (NSCLC)

In the US, ~15% of patients with metastatic lung adenocarcinoma have tumors harboring “driver” mutations in the EGFR gene, which demonstrate major clinical responses to EGFR Tyrosine Kinase Inhibitors (TKIs). The third-generation EGFR TKI osimertinib shows superior clinical activity compared to early-generation EGFR TKIs, however, essentially all tumors eventually develop resistance to osimertinib. We previously demonstrated that EGFR TKIs induce “adaptive persistence” in cancer cells with stem-like properties, allowing these cells to survive and acquire resistance. Activation of β-catenin and downstream signaling components is one of the major pathways enabling this adaptive persistence. Our goal is to identify and validate β-catenin inhibitors that have the potential to improve the depth and duration of response to osimertinib in EGFR-mutant NSCLC. We used the EGFR-mutant NSCLC cell lines HCC827, HCC4006, and H1975 to evaluate the effects of treatment with osimertinib and a β-catenin inhibitor, BC2059. Cell viability assays were done to determine the IC50 values of BC2059 in this panel of cell lines. ALDEFLUOR assays were performed to assay for induced stem-ness. We also assessed β-catenin protein levels and downstream signaling events in various treatment conditions. To evaluate the preclinical activity of β-catenin inhibition, we treated mice bearing HCC4006 and HCC827 xenografts with osimertinib alone or in combination with BC2059. Preclinical activity was assessed through progression free survival and overall survival. Our in vitro studies demonstrated that NSCLC cell lines are sensitive to β-catenin inhibition in a time and dose-dependent manner, and the addition of BC2059 to osimertinib enhances tumor cell killing. Osimertinib treatment increased non-phosphorylated and total β-catenin levels in EGFR-mutant cell lines. We further showed that osimertinib treatment induced ALDH activity that was sensitive to β-catenin inhibition in HCC4006 and HCC827 cells. BC2059 decreased osimertinib-induced ALDH positivity by &gt;10 fold in HCC4006 and ~2 fold in HCC827 cells. Osimertinib treatment increased levels of the secreted β-catenin transcriptional target PAI1 in cultured media, which was inhibited by BC2059. Our preclinical studies also demonstrated that the combination of osimertinib and BC2059 decreased tumor recurrence and improved overall survival in mice bearing EGFR-mutant human lung cancer xenografts. Overall, our studies show that osimertinib in combination with the β-catenin inhibitor BC2059 enhances osimertinib efficacy and delays tumor recurrence, possibly by targeting drug-tolerant persistent clones that are enriched for with EGFR TKI treatment alone. These data provide strong rationale for a clinical trial that evaluates the combination of osimertinib and BC2059 in patients with metastatic EGFR-mutant NSCLC.

Citation Format: Shankar Suman, Shu-Xiao Guan, Nastaran Navari, Rajeswara Rao Arasada, David P. Carbone, Regan M. Memmott. Targeting β-catenin enhances the therapeutic efficacy of osimertinib in EGFR- mutant non-small cell lung cancer (NSCLC) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1110.

Thiophene-based Schiff base ligand as ionophore for Ni(II)-selective polyvinyl chloride membrane electrode

A synthesized Schiff base 2-acetylthiophene semicarbazone (3) was used for the preparation of Ni2+ selective polyvinyl chloride (PVC) membrane electrode. The prepared electrode with the optimized composition, PVC:3:sodium tetraphenylborate:di-n-butylphthalate as 33:6:3:58 exhibited a Nernstian response over the working range of 5.0 × 10−6–5.0 × 10−2 mol l−1 with a slope of 29.0 ± 0.3 mV/concentration. The electrode showed good selectivity towards Ni2+ with respect to several metal ions in the pH range of 2.5–10.0 in <15 s with a detection limit of 4.7 × 10−6 mol l−1. The electrode showed the additional benefit of working in partially nonaqueous media having up to 15% (v/v) methanol or ethanol. This electrode was also successfully applied in Ni2+ ion potentiometric titration with ethylenediaminetetraacetic acid as an indicator electrode.

AB1231 2019 LUPUS CLASSIFICATION CRITERIA SCORE PREDICTS FUTURE LUPUS HOSPITAL ADMISSION

Background:

There are several validated tools to quantitate lupus disease activity, end-organ damage and overall fragility. An algorithm to predict the hospitalization risk in lupus patients was proposed by Li et al1. That algorithm was able to effectively screen patients at increased risk of hospitalization using EHR information only. Recently, the new 2019 Lupus classification criteria score has been noted to accurately predict 10 year mortality2.

Objectives:

To test the above 2 algorithms with potential to predict lupus related hospital admissions.

First, we attempted to validate the existing algorithm from the index study of Li et al to predict lupus hospitalization.

Second, we tested the 2019 lupus clinical classification score for its ability to predict hospitalizations.

Methods:

A retrospective chart review was performed using EHR data collected from 2013 to 2018 at University of Kentucky (UK) Medical Center. Inclusion criteria were 18 years or older at first outpatient rheumatology appointment at UK, at least 3 outpatient rheumatology visits at UK, and ICD 9/10 code for Lupus. A total of 217 patients met inclusion criteria. Variables similar to the index study were extracted from patients’ first outpatient rheumatology visit at UK. Additionally, 2019 Lupus Classification Criteria score was calculated. Patients who were subsequently hospitalized, manual chart review was done to determine if the hospitalization was attributable to lupus or not.

Results:

Table 1 shows differences between the variables predicting hospitalization in patients in this study (UK) and the Ohio State University (OSU) cohort from whom the admission predicting algorithm was derived1. All the risk factors that were found to predict lupus hospitalization in the index study, failed to achieve a statistical significance in our validation study.

Table 1.

Differences in the variables predicting hospitalization between Index and Validation Cohort

Variables predicting Lupus HospitalizationIndex Study (Ohio State),% of patients(n=226)Validation Study(University of Kentucky)% of patients; (n=217)African American33%18%Creatinine > 1.217%7%Hemoglobin < 11g/dl79%18%Platelets < 180 / uL75%22%High Risk immunosuppression35%9. 2%Missed appointment27%25%

There was more success predicting lupus hospitalization using the 2019 lupus classification criteria score (CCS) (Figure 1). A CCS >=19 predicted higher risk of lupus related hospitalization vs CCS < 19 over the ensuing 2 years (p-0.05).

Figure 1.

Kaplan- Meier Survival Analysis comparing the risk of hospitalization between the groups with 2019 Lupus classification criteria score (CCS) of less than 19 (red) and more/equal to 19 (blue). A time-dependent effect, with the admission free survival curves crossing at two years (Figure 1), indicated a 1 out of 3 chance of lupus related admission during the first 6 months for a high CCS score > =19.

Conclusion:

We failed to validate the EHR algorithm identifying patients at high risk for lupus hospitalization in our less severely affected cohort with fewer admission events to analyze. Nonetheless, “criteria counting” using the weightings of the 2019 lupus classification criteria was granular enough to make these case finding criteria themselves prognostic for future hospitalization risk. It is likely that existing EHRs, using protocols based upon classification criteria scores, are now capable of predicting survival, costs, and admissions automatically.

References:

[1]D Li et al. Determining risk factors that increase hospitalizations in patients with systemic lupus erythematosus, Lupus (2018) 27, 1321–1328

[2]Carneiro et al. A comparison of three classification criteria sets for Systemic Lupus Erythematosus – a study looking at links to outcome and mortality; Arthritis Care Res (Hoboken). 2019 Sep 10. doi: 10.1002/acr.24061

Disclosure of Interests:

Saurav Suman: None declared, Mervat Eissa: None declared, Heidi Rogers: None declared, Aleksander Lenert: None declared, Arnold Stromberg: None declared, william roberts Shareholder of: Own Stocks of Pfizer and Novartis

Possible Role of Myoglobin in Regulating Calpain-1 Activity in Postmortem Beef Muscle

ObjectivesPrevious research revealed a relationship between meat color and beef tenderness and indicated that myoglobin can inhibit calpain-1 in solution. The objective of this study was to determine the extent to which myoglobin and beef color are associated with calpain activity and beef tenderness.Materials and MethodsBeef Longissimus dorsi samples from the left side of Holstein beef carcasses (n = 21) were collected immediately post exsanguination on the processing floor for 0 h analyses. Muscle temperature and pH was measured at 0, 24, and 48 h postmortem. After USDA quality and yield grade determination, steaks (n = 6) were removed from the right side of each carcass (n = 21) at 48 h for analyses at 48 and 336 h postmortem. Color (L*, a*, and b* values), surface myoglobin redox forms, metmyoglobin reducing activity (MRA), total myoglobin concentrations, slice shear force (SSF), Warner-Bratzler shear force (WBSF) were measured. Calpain-1 concentrations and autolysis were determined via Western blot at 0, 48, and 336 h.ResultsDecline in muscle pH was 6.4, 5.8, and 5.6 at 0, 24, and 48 h, respectively. Shear force values at 48 h were 73.19 N for WBSF and 384.21 N for SSF and at 336 h were 48.75 N for WBSF and 260.47 N for SSF. Myoglobin reducing activity at 336 h was positively correlated to WBSF at 48 h and negatively correlated to calpain-1 concentration at 0 h (P < 0.05; Table 9). Color measurements of L* and b* at 48 h were moderately correlated with WBSF at 336 h (P < 0.05; Table 9). The b* measurement at 336 h showed a moderate relationship to calpain-1 concentration at 0 h (P < 0.05; Table 9).ConclusionModerate correlations between color and tenderness measurements taken at 48 h with those taken at 336 h were discovered indicating that myoglobin may impact calpain-1 in vivo.Table 9Correlations (P-values) between selected color and tenderness measurements (n = 21)

Comparison of Lipid and Protein Oxidation Products and their Impact on Colour Stability in Bison Longissimus Lumborum and Psoas Major Muscles

ObjectivesTo compare lipid (malondialdehyde [MDA], 4-hydroxy-2-nonenal [HNE]) and protein (carbonyl content [CAR]) oxidation products and determine their influence on color stability in two bison muscles (longissimus lumborum [LL; color stable] and psoas major [PM; color labile]).Materials and MethodsA total of 10 longissimus lumborun (LL) and 10 psoas major (PM) from five A1 grade bison carcasses were obtained from a commercial slaughter plant within 48 h post-mortem. From each muscle, a 10-cm thick piece was removed and subsampled for evaluation of pH, MDA (by thiobarbituric acid assay), HNE (by ELISA) and CAR (by 2,4-dinitrophenylhydrazine). These measurements allowed the establishment of a baseline for the different oxidation products. The remainder of the muscles were cut into two equal portions, and each portion was vacuum-packaged and assigned to an ageing period of 7 and 14 d at 2°C. At the end of each ageing period, each muscle portion was removed from their packages, pH measured, and steaks obtained for sensory (muscle and discoloration scores) and instrumental color measurements (L*, a* and b*) over 5 d of retail display, and for estimation of MDA, HNE and CAR. After 5 d in retail display and following color and pH measurements the steaks were removed and collected for MDA, HNE and CAR determination. Data were analyzed as a completely randomized design with a split-split plot arrangement. Additionally, correlation and regression analysis were performed to identify the influence of the measured attributes on color.ResultsRegardless of the ageing time, LL showed greater redness and lower surface discoloration by instrumental (a* value; P = 0.04) and sensory (P < 0.01) color evaluation than PM at the end of the retail display. Furthermore, LL exhibited lower MDA, HNE and CAR content compared to PM (P < 0.05). A three-way interaction (muscle × ageing time × retail day display) was detected on MDA content, where PM presented a higher level of MDA with increasing ageing time and retail display than LL (P = 0.02). The pH was not different between LL and PM (P > 0.05) steaks.In both muscles, Pearson (r) and Spearman (rs) correlation coefficients indicated that MDA was the oxidation compound showing the highest correlation to a* (r = –0.78; P < 0.01) and discoloration (rs = 0.81; P < 0.01) scores, followed by a moderate correlation with HNE and CAR (r or rs < 0.7; P < 0.01). The pH did not exhibit correlation with color traits, except for lightness, in both muscles. For the stepwise regression analysis, the main variable entered into the equation for predicting a*, color and discoloration score in PM muscle was MDA with an R2 of 0.72, 0.75 and 0.78, respectively, while for LL muscle, MDA presented an R2 of 0.62, 0.68 and 0.66;, respectively. The pH, HNE and CAR only explained an additional 2% of the variation in those attributes.ConclusionThe results of color attributes corroborated that bison LL is a color-stable muscle due to the lower level of protein and lipid oxidation products developed during storage and retail display compared to PM muscle, which is considered color-labile muscle. The MDA seemed to have remarkable importance in the color deterioration than HNE and CAR, particularly in bison PM muscle.

Myoglobin Modeling to Study Species-Specific Differences in the Distance Between Heme Iron and Proximal and Distal Histidines

ObjectivesSpecies-specific differences in amino acid sequence influence myoglobin redox properties. Previous studies reported that the number and location of histidine residues can influence myoglobin redox stability. However, limited knowledge is currently available on the species-specific differences in the distances between the proximal (His 93) and distal (His 64) histidines and the heme iron in myoglobin. The objective of the current research was to utilize homology-based modeling to determine the distances between the proximal and distal histidines and the heme iron in the myoglobins from beef, pork, goat, bison, sheep, water-buffalo, venison, and emu.Materials and MethodsThe homology-based modeling was conducted using the Iterative Threading Assembly Refinement server (I-TASSER), which identifies the homologous structure models of myoglobins (beef, pork, goat, bison, sheep, water-buffalo, venison, and emu) from Protein Data Bank (PDB) using an algorithm named Local Meta-Threading-Server. The secondary structure of the target protein was predicted based on sequence information from the Protein Secondary Structure PREDiction algorithm. The lowest free energy conformations of the proteins were determined by SPICKER (a clustering approach to identify near-native protein folds). Refinement of the low free energy conformations were done by using Fragment Guided Molecular Dynamics simulations and ModRefiner. Prediction of the ligand-binding site of the target proteins were made by COACH algorithm. The distances between histidines (His 64 and His 93) and the iron in the heme group in the predicted structure of eight different species were determined using PyMOL, a computer software used for molecular visualization.ResultsThe homology-based modeling has shown that despite having 80% sequence similarity and conserved histidine residues (His 64 and His 93), the distance between the distal histidine (His 64) and heme iron varied between 4.3–5.5 Angstrom. Pork myoglobin has the shortest distance, and beef myoglobin has the longest distance. The distance between the proximal histidine (His 93) to the heme varied between 1.9 to 3 Angstrom; sheep myoglobin had the shortest and bison had the longest.ConclusionThe results suggest that in addition to the inherent differences in muscle biochemistry, variations in myoglobin structure also contributes to species-specific differences in meat color.

Phospho-proteomic analysis of primary human colon epithelial cells during the early Trypanosoma cruzi infection phase

The protozoan parasite Trypanosoma cruzi, the causative agent of Chagas disease, causes severe morbidity and mortality in afflicted individuals. About 30% of T. cruzi-infected individuals present with cardiac, gastrointestinal tract, and/or neurological disorders. Megacolon, one of the major pathologies of Chagas disease, is accompanied by gastrointestinal motility disorders. The molecular mechanism of T. cruzi-mediated megacolon in Chagas disease is currently unknown. To decipher the molecular mechanism of T. cruzi-induced alteration in the colon during the early infection phase, we exposed primary human colonic epithelial cells (HCoEpiC) to invasive T. cruzi trypomastigotes at multiple time points to determine changes in the phosphoprotein networks in the cells following infection using proteome profiler Human phospho-kinase arrays. We found significant changes in the phosphorylation pattern that can mediate cellular deregulations in colonic epithelial cells after infection. We detected a significant increase in the levels of phosphorylated heat shock protein (p-HSP) 27 and transcription factors that regulate various cellular functions, including c-Jun and CREB. Our study confirmed significant upregulation of phospho (p-) Akt S473, p-JNK, which may directly or indirectly modulate CREB and c-Jun phosphorylation, respectively. We also observed increased levels of phosphorylated CREB and c-Jun in the nucleus. Furthermore, we found that p-c-Jun and p-CREB co-localized in the nucleus at 180 minutes post infection, with a maximum Pearson correlation coefficient of 0.76±0.02. Increased p-c-Jun and p-CREB have been linked to inflammatory and profibrotic responses. T. cruzi infection of HCoEpiC induces an increased expression of thrombospondin-1 (TSP-1), which is fibrogenic at elevated levels. We also found that T. cruzi infection modulates the expression of NF-kB and JAK2-STAT1 signaling molecules which can increase pro-inflammatory flux. Bioinformatics analysis of the phosphoprotein networks derived using the phospho-protein data serves as a blueprint for T. cruzi-mediated cellular transformation of primary human colonic cells during the early phase of T. cruzi infection.

Metabolic fingerprinting in breast cancer stages through 1H NMR spectroscopy-based metabolomic analysis of plasma

Breast cancer (BC) is one of the most common malignancies among women worldwide, which is indeed associated with metabolic reprogramming. However, BC is a very complex and heterogeneous disease, which can relate with the changes in metabolic profiles during BC progression. Hence, investigating the metabolic alterations during BC stage progression may reveal the deregulated pathways and useful metabolic signatures of BC. To demonstrate the metabolic insights, we opted ¹H NMR spectroscopy based metabolomics of blood plasma of early and late stage BC (N = 72) with age and gender matched healthy subjects (N = 50). Further, the metabolic profiles were analyzed to delineate the potential signatures of BC by performing multivariate and nonparametric statistical analysis in early and late stages of BC in comparison with healthy subjects. Sixteen metabolites levels were differentially changed (p < 0.05) in the early and late stages of BC from healthy subjects. Among them, the levels of hydroxybutyrate, lysine, glutamate, glucose, N-acetyl glycoprotein, Lactate were highly distinguished in BC stages and showed a good biomarker potential using receiver-operating curves based diagnostic models. Furthermore, the significant modulation and good diagnostic performances of glutamate, N-acetyl glycoprotein and Lactate in LBC as compared to EBC give their significance in the BC progression. In general, our observations demonstrate that these panels of metabolites may act as vital component of the metabolism of early to late stage BC progression. Our results also open new avenue towards early and late stage BC diagnosis and intervention implying metabolomics approaches.

Resveratrol improves the anticancer effects of doxorubicin in vitro and in vivo models: A mechanistic insight

BACKGROUND

Resveratrol (RSVL), a well known dietary compound and in combination with doxorubicin (DOX) has gained a global importance for cancer prevention. However, mechanism of action by this combination is not well understood till date.

HYPOTHESIS

The synergistic combination of RSVL and DOX might be more effective in anti-cancer activity by modulating the diverse cancer signaling pathways as compared to their alone treatments.

METHODS

The cytotoxicity of alone and combination doses of RSVL and DOX were analyzed by colorimetric MTT(3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide) cell proliferation assay. The migration and colony forming abilities were evaluated by wound healing and clonogenic assays. Apoptosis was detected by Annexin V/PI and DAPI stainings. The cell cycle and intracellular reactive oxygen species (ROS) generation were measured by flow cytometry. The differential expression of genes and proteins were measured by qRT-PCR and western blotting analyses. Finally, in-vivo studies were performed in Ehrlich ascitic carcinoma (EAC) mouse model.

RESULTS

The synergistic combination of DOX (IC20) and RSVL (IC30) was selected based on the combination index values in MCF-7 and MDA-MB-231 cell lines. This combination showed potent growth inhibition with ∼2.5 fold of dose advantage and also significantly decreased the wound healing and clonogenic potential of breast cancer cells. The combination treatment was also found to inhibit the inflammatory response (NF-kB, COX-2), autophagic flux (LC3, Beclin-1), redox regulation (Nrf2) and induces apoptosis (BAX: BCL-2 ratio and Caspase-9) in breast cancer cells. Further, combined dosages of DOX (5 mg/kg b.wt) and RSVL (10 mg/kg b.wt) inhibited tumor volume with increased life span (139%, p value<0.05) in Ehrlich ascitic carcinoma (EAC) cells bearing mice.

CONCLUSION

In brief, our results suggested that resveratrol chemosensitizes doxorubicin in combination, through inhibiting breast cancer cells proliferation and invasion, and inducing apoptosis via suppression of chronic inflammation and autophagy.

Diallyl Sulfide and Its Role in Chronic Diseases Prevention

Diallyl sulfide (C₆H₁₀S, DAS) is one of the novel natural organosulfur compounds, which is mostly obtained from the genus Allium plants. Numerous studies have revealed several unique properties of DAS in terms of its health-promoting effects. DAS has proved to be anticancer, antimicrobial, anti-angiogenic, and immunomodulatory like unique functions as demonstrated by the multiple investigations. Diallyl sulfide can also impede oxidative stress and chronic inflammation as suggested by the literature. Studies also explored that DAS could thwart the development of chronic diseases like cancer, neuronal, cardiovascular disease through modulating mechanistic pathways involved in pathogenesis. In this book chapter, we have attempted to give the comprehensive view on DAS about the physiochemical and biological properties, and its preventive role in chronic diseases with a mechanistic overview.

Current perspectives of molecular pathways involved in chronic inflammation-mediated breast cancer

Inflammation has multifaceted role in cancer progression including initiation, promotion and invasion by affecting the immune surveillance and associated signaling pathways. Inflammation facilitates the over-expression of cytokines, chemokines and growth factors involved in progression of different cancers including breast cancer progression. Deregulation of biological processes such as oxidative stress, angiogenesis, and autophagy elicit favorable immune response towards chronic inflammation. Apart from the role in carcinogenesis, chronic inflammation also favors the emergence of drug resistance clones by inducing the growth of breast cancer stem-like cells. Immunomodulation mediated by cytokines, chemokines and several other growth factors present in the tumor microenvironment regulate chronic inflammatory response and alter crosstalk among various signaling pathways such as NF-κB, Nrf-2, JAK-STAT, Akt and MAPKs involved in the progression of breast cancer. In this review, we focused on cellular and molecular processes involved in chronic inflammation, crosstalk among different signaling pathways and their association in breast cancer pathogenesis.

The pro-apoptotic role of autophagy in breast cancer

BACKGROUND

Autophagy is a catabolic process that has a vital role in cancer progression and treatment. Current chemotherapeutic agents, which target autophagy, result in growth inhibition in many cancer types. In this study, we examined the role of autophagy in breast cancer (BCa) patients as well as BCa cell lines.

METHODS

Tissue microarray was used to detect the expression of an autophagy marker, LC3B in BCa patients (normal/hyperplasia=8; grade-I=15, grade-II=84, and grade-III=27) and BCa cell lines. To modulate the activation of autophagy, we used novel herbal compound nimocinol acetate (NA) in BCa cell lines and the anticancer activity was measured by phenotypic and molecular analysis.

RESULTS

LC3B is highly expressed in tumours as compared with normal tissues. Activation of LC3B in NA-treated BCa (MCF-7 and MDA-MB-231) cells was evident as compared with other autophagy makers. Further, our results confirmed that NA-transcriptionally regulates LC3B (as confirmed by mRNA levels and reporter assay), which resulted in the formation of acidic autophagy vesicles and autolysosomes in BCa cells. Nimocinol acetate inhibited mTOR-mediated pro-survival signalling that resulted in inhibition of growth in BCa cells without affecting normal breast epithelial cells. Downregulation of LC3B expression by siRNA significantly inhibited the anticancer effects of NA in BCa cells.

CONCLUSIONS

Together, our results suggest that LC3B is highly expressed in BCa tissues and increasing the threshold of LC3B activation dictates the pro-apoptotic function, which in turn, suppresses the growth of BCa cells. Nimocinol acetate could be a potential agent for treatment of BCa.

Corneal stromal pseudohypopyon in a pseudophakic patient

BACKGROUND

Corneal stromal pseudohypopyon is a rare entity.

CASE

A 65-year-old female developed a suture abscess in her pseudophakic right eye, three years after conventional extra-capsular cataract extraction with posterior chamber intraocular lens implantation. Pusfrom the suture abscess tracked down the corneal stromal layers and formed a pus level leading to the appearance of a corneal intra-stromal pseudo-hypopyon.

CONCLUSION

This case is unique due to its unusual clinical presentation and highlights the fact that corneal pseudo hypopyon may occur without any associated anterior chamber hypopyon or Descemet's detachment.

Use of the pro-seal laryngeal mask airway facilitates percutaneous dilatational tracheostomy in an intensive care unit

Purpose:

To study the feasibility of using the pro-seal laryngeal mask airway (LMA) for airway maintenance during bronchoscopic-guided percutaneous tracheostomy.

Materials and Methods:

Observational study of 60 patients in a 16-bed intensive care unit. The patient’s tracheal tube was exchanged for a pro-seal LMA before undertaking percutaneous tracheostomy.

Results:

Inspiratory pressure and tidal volumes achieved during the procedure were recorded. The median peak inspiratory pressure was 25 (standard deviation 4.4) cm H2O. There was no loss of tidal volume in 30 patients, a loss of less than 100 mL/breath in 27, and loss of more than 100 mL in 3 patients. A pro-seal LMA successfully maintained the airway and allowed adequate ventilation during per-cutaneous tracheostomy in all 60 patients. In all patients, fiber optic bronchoscopy through the pro-seal LMA provided a clear view of the cords and trachea and there was no laryngeal or tracheal soiling at any stage of the procedure.

Conclusion:

The pro-seal LMA provides a reliable airway and allows effective ventilation during percutaneous tracheostomy. The passage of a fiberscope through the pro-seal LMA and glottis is easy and provides a clear view of the upper trachea.

Primary pericardial mesothelioma presenting as pericardial constriction: a case report

A 19 year old man presented with a six month history of chest pain, dyspnoea, and lethargy and was found on an echocardiogram to have a dilated left ventricle with a small pericardial effusion. Ramipril and a course of steroids were tried but serial echocardiograms showed a persistently thickened pericardium and slowly developing features of constriction. On computed tomography, a large mediastinal mass encasing the heart, along with para-aortic and paratracheal lymphadenopathy, was found. Right heart catheter studies showed equal pressures in all four chambers. His deteriorating clinical condition led to a pericardiectomy. Histology confirmed primary pericardial mesothelioma. The patient died soon after surgery.

Successful management of infantile hypertrophic pyloric stenosis with atropine sulfate

OBJECTIVE

To evaluate the effectiveness of atropine sulfate in management of infantile hypertrophic pyloric stenosis (IHPS).

DESIGN

Prospective observational.

SUBJECT

Patients attending the hospital with complaints of persistent vomiting and later clinically and sonographically diagnosed as cases of IHPS were selected for the trial.

METHODS

Atropine was initially administered intravenously in a dose of 0.06 mg/kg/day in eight divided doses, increased by 0.15 mg/kg/day till vomiting ceased and remained so for a period of 24 hours at a stretch and ultrasonography showed a transit time (of gastric contents through pyloric canal) of less than 1 minute. Intravenous atropine was then substituted by oral atropine at double the effective IV dose for 3 weeks. Ultrasonographic evaluation of pyloric muscle thickness and length was done at the commencement of IV treatment, after completion of oral treatment and at 3,6,9,12 and 15 months follows up. Transit time of gastric contents was measured at the commencement of intravenous treatment and then daily after the vomiting stopped for more than 24 h at a stretch.

RESULTS

Medical treatment of IHPS with atropine was successful in 50/52 (96.2%) cases. Vomiting ceased in 1-3 days in all patients with mild hypertrophy and in 4-7 days in all the cases with moderate hypertrophy. In all except 2 patients with severe hypertrophy, vomiting ceased in 8-12 days. These two cases continued to vomit at least once daily even after 2 weeks of IV treatment and ultimately opted out for pyloromyotomy. All the 50 medically treated children made uneventful recovery during oral therapy except 3 cases (6%) in whom vomiting recurred during the follow-up. These 3 children later responded by increasing the dose of oral atropine. All of them began to gain weight by the time oral therapy was commenced and ultrasonographic evidence of normalization of pylorus was observed in all these children 3-15 months after completion of oral therapy.

CONCLUSION

Atropine sulfate proved to be an effective and safe treatment option for IHPS.