Extended exposure to low doses of azacitidine induces differentiation of leukemic stem cells through activation of myeloperoxidase

Oral azacitidine (oral-Aza) treatment results in longer median overall survival (OS) (24.7 vs. 14.8 months in placebo) in patients with acute myeloid leukemia (AML) in remission after intensive chemotherapy. The dosing schedule of oral-Aza (14 days/28-day cycle) allows for low exposure of Aza for an extended duration thereby facilitating a sustained therapeutic effect. However, the underlying mechanisms supporting the clinical impact of oral-Aza in maintenance therapy remain to be fully understood. In this preclinical work, we explore the mechanistic basis of oral-Aza/extended exposure to Aza through in vitro and in vivo modeling. In cell lines, extended exposure to Aza results in sustained DNMT1 loss, leading to durable hypomethylation, and gene expression changes. In mouse models, extended exposure to Aza, preferentially targets immature leukemic cells. In leukemic stem cell (LSC) models, the extended dose of Aza induces differentiation and depletes CD34+CD38- LSC. Mechanistically, LSC differentiation is driven in part by increased myeloperoxidase (MPO) expression. Inhibition of MPO activity either by using an MPO-specific inhibitor or blocking oxidative stress, a known mechanism of MPO, partly reverses the differentiation of LSC. Overall, our preclinical work reveals novel mechanistic insights into oral-Aza and its ability to target LSC.

Ionotropic receptors mediate olfactory learning and memory in Drosophila

Phenylacetaldehyde (PAH), an aromatic compound, is present in a diverse range of fruits including overripe bananas and prickly pear cactus, the two major host fruits for Drosophila melanogaster. PAH acts as a potent ligand for the ionotropic receptor 84a (IR84a) in the adult fruit fly and it is detected by the IR84a/IR8a heterotetrameric complex. Its role in the male courtship behavior through IR84a as an environmental aphrodisiac is of additional importance. In D. melanogaster, two distinct kinds of olfactory receptors, that is, odorant receptors (ORs) and ionotropic receptors (IRs), perceive the odorant stimuli. They display unique structural, molecular, and functional characteristics in addition to having different evolutionary origins. Traditionally, olfactory cues detected by the ORs such as ethyl acetate, 1-butanol, isoamyl acetate, 1-octanol, 4-methylcyclohexanol, etc. classified as aliphatic esters and alcohols have been employed in olfactory classical conditioning using fruit flies. This underlines the participation of OR-activated olfactory pathways in learning and memory formation. Our study elucidates that likewise ethyl acetate (EA) (an OR-responsive odorant), PAH (an IR-responsive aromatic compound) too can form learning and memory when associated with an appetitive gustatory reinforcer. The association of PAH with sucrose (PAH/SUC) led to learning and formation of the long-term memory (LTM). Additionally, the Orco1 , Ir84aMI00501 , and Ir8a1 mutant flies were used to confirm the exclusive participation of the IR84a/IR8a complex in PAH/SUC olfactory associative conditioning. These results highlight the involvement of IRs via an IR-activated pathway in facilitating robust olfactory behavior.

Phenylacetaldehyde induced olfactory conditioning in Drosophila melanogaster (Diptera: Drosophilidae) larvae

Phenylacetaldehyde (PAH), an aromatic odorant, exists in varied fruits including overripe bananas and prickly pear cactus, the 2 major host fruits of Drosophila melanogaster. It acts as a potent ligand for the Ionotropic receptor 84a (IR84a) and the Odorant receptor 67a (OR67a), serving as an important food and courtship cue for adult fruit flies. Drosophila melanogaster larvae respond robustly to diverse feeding odorants, such as ethyl acetate (EA), an aliphatic ester. Since the chemical identity and concentration of an odorant are vital neural information handled by the olfactory system, we studied how larvae respond to PAH, an aromatic food odorant with aphrodisiac properties for adult flies. Our findings revealed that PAH attracted larvae significantly in a dose-dependent manner. Larvae could also be trained with PAH associated to appetitive and aversive reinforcers. Thus, like EA, PAH might serve as an important odorant cue for larvae, aiding in food tracking and survival in the wild. Since IR84a/IR8a complex primarily governs PAH response in adult flies, we examined expression of Ir84a and Ir8a in early third-instar larvae. Our experiments showed the presence of Ir8a, a novel finding. However, contrary to adult flies, PAH-responsive Ir84a was not found. Our behavioral experiments with Ir8a1 mutant larvae exhibited normal chemotaxis to PAH, whereas Orco1 mutant showed markedly reduced chemotaxis, indicating an OR-mediated neural circuitry for sensing of PAH in larvae. The results obtained through this study are significantly important as information on how larvae perceive and process PAH odorant at the neuronal level is lacking.

Single-cell analysis of localized prostate cancer patients links high Gleason score with an immunosuppressive profile

BACKGROUND

Evading immune surveillance is a hallmark for the development of multiple cancer types. Whether immune evasion contributes to the pathogenesis of high-grade prostate cancer (HGPCa) remains an area of active inquiry.

METHODS

Through single-cell RNA sequencing and multicolor flow cytometry of freshly isolated prostatectomy specimens and matched peripheral blood, we aimed to characterize the tumor immune microenvironment (TME) of localized prostate cancer (PCa), including HGPCa and low-grade prostate cancer (LGPCa).

RESULTS

HGPCa are highly infiltrated by exhausted CD8⁺ T cells, myeloid cells, and regulatory T cells (TRegs). These HGPCa-infiltrating CD8⁺ T cells expressed high levels of exhaustion markers including TIM3, TOX, TCF7, PD-1, CTLA4, TIGIT, and CXCL13. By contrast, a high ratio of activated CD8⁺  effector T cells relative to TRegs and myeloid cells infiltrate the TME of LGPCa. HGPCa CD8⁺  tumor-infiltrating lymphocytes (TILs) expressed more androgen receptor and prostate-specific membran antigen yet less prostate-specific antigen than the LGPCa CD8⁺  TILs. The PCa TME was infiltrated by macrophages but these did not clearly cluster by M1 and M2 markers.

CONCLUSIONS

Our study reveals a suppressive TME with high levels of CD8⁺ T cell exhaustion in localized PCa, a finding enriched in HGPCa relative to LGPCa. These studies suggest a possible link between the clinical-pathologic risk of PCa and the associated TME. Our results have implications for our understanding of the immunologic mechanisms of PCa pathogenesis and the implementation of immunotherapy for localized PCa.

Gefitinib: An Updated Review of its Role in the Cancer Management, its Nanotechnological Interventions, Recent Patents and Clinical Trials

BACKGROUND

Gefitinib, a tyrosine kinase inhibitor, is effectively used in the targeted treatment of malignant conditions. It suppresses the signal transduction cascades leading to cell proliferation in the tumors and is now currently approved in several countries globally as secondline and third-line treatment for non-small cell lung cancer (NSCLC).

OBJECTIVE

This review is aimed to summarize the journey of gefitinib as an established anticancer drug for the management of various cancers. Moreover, this review will focus on the mechanism of action, established anticancer activities, combination therapy, nanoformulations, as well as recent clinical trials and patents on gefitinib.

METHODS

The data for this review was collected from scientific databases such as PubMed, Science Direct, Google Scholar, etc. Recent patents on gefitinib granted in the last two years were collected from databases Patentscope, USPTO, Espacenet, InPASS and Google Patents. Data for the recent clinical trials were obtained from the U.S. National Library of Medicine database.

RESULTS

Recent pre-clinical and clinical studies during the period 2015-2021 demonstrating the efficacy of gefitinib were selected and summarized. Total 31 patents were granted in the year 2020-2021 concerning gefitinib. The efficacy of gefitinib against lung cancer, as well as other cancer types, including breast, prostate, colon, cervix etc., was reviewed.

CONCLUSION

Gefitinib showed significant advantages in being more effective, safer and more stable, and the associated biopharmaceutical problems are addressed by the application of nanotechnology. The combination therapy using gefitinib and various anticancer molecules of natural and synthetic origin has shown an improved anticancer profile.

Myeloma Genome Project Panel is a Comprehensive Targeted Genomics Panel for Molecular Profiling of Patients with Multiple Myeloma

PURPOSE

We designed a comprehensive multiple myeloma targeted sequencing panel to identify common genomic abnormalities in a single assay and validated it against known standards.

EXPERIMENTAL DESIGN

The panel comprised 228 genes/exons for mutations, 6 regions for translocations, and 56 regions for copy number abnormalities (CNA). Toward panel validation, targeted sequencing was conducted on 233 patient samples and further validated using clinical FISH (translocations), multiplex ligation probe analysis (MLPA; CNAs), whole-genome sequencing (WGS; CNAs, mutations, translocations), or droplet digital PCR (ddPCR) of known standards (mutations).

RESULTS

Canonical immunoglobulin heavy chain translocations were detected in 43.2% of patients by sequencing, and aligned with FISH except for 1 patient. CNAs determined by sequencing and MLPA for 22 regions were comparable in 103 samples and concordance between platforms was R2 = 0.969. Variant allele frequency (VAF) for 74 mutations were compared between sequencing and ddPCR with concordance of R2 = 0.9849.

CONCLUSIONS

In summary, we have developed a targeted sequencing panel that is as robust or superior to FISH and WGS. This molecular panel is cost-effective, comprehensive, clinically actionable, and can be routinely deployed to assist risk stratification at diagnosis or posttreatment to guide sequencing of therapies.

Antibacterial activity of Ricinus communis plant extract against antibiotic resistant Helicobacter pylori and Gluconobacter oxydans isolated from fresh apple juices samples

Bacteria were isolated from samples of Fresh Apple juices from shops of three different localities of Lahore. Analysis of samples from Liberty, Anarkali and Yateem khana Markets show different levels of contamination. There were pathogenic and non-pathogenic bacteria in all samples and were identified by the morphological and biochemical tests. Most of the plasmids of pathogenic bacteria were 4kb in their molecular size. Ribotyping of 16S ribosomal RNA gene sequencing was done to confirm Helicobacter pylori strain and Gluconobacter oxydans. The highest sensitivity of 210mm was shown by Enterobacter sp. against Aztheromysine disk (15µg) while Micrococcus sp. was highly resistant against all of the Antibiotics applied. The antibiotic resistance of pathogenic bacteria was also checked against Ricinus communis plant's extracts, all isolated bacterial pathogens were resistant but only, E.coli was inhibited at 300µl of the extracts. Presence of pathogenic bacteria in Apple juice samples was due to contamination of sewage water in drinking water while some of these pathogenic bacteria came from Apple's tree and other from store houses of fruits.

Knowledge of Autism Spectrum Disorder Among 2nd to 4th Phase MBBS Students of Bangladesh

Autism spectrum disorder (ASD), being one of the fastest-growing disabilities in children, is an omnipresent, immutable neurodevelopmental disorder characterized by impaired socialization, impaired verbal and non-verbal communication, restricted interests, and repetitive behaviour patterns. A descriptive cross-sectional study was conducted from 30 October to 30 November 2019 among the MBBS students of 21 medical colleges in Bangladesh to assess their knowledge of autism. The 'Knowledge about Childhood Autism among Health Workers (KCAHW)' questionnaire containing 19 item questions divided into four domains was used. The total median score in the KCAHW questionnaire is 13 out of 19. The final total of respondents numbered 483. There were 215 (44.51%) male and 268 (55.49%) female students. Among 21 medical colleges, 10 are situated in the Dhaka district and 11 outside Dhaka; 14 medical colleges were public, and seven were private. The study shows that students' knowledge of autism spectrum disorder (ASD) is not up to the mark. While assessing the knowledge in each domain, Domain 4 (knowledge regarding nature, comorbidities, and onset) shows that only 32.6% of students of 4th phase and 21.5% of other phases have scored more than the median value, revealing that medical students were not familiar with nature, comorbidities, and the onset of ASD. It can be reliably diagnosed before two years of age, but the practical scenario is a different picturesque. Thus, medical students should have bona fide knowledge to diagnose this progressively prevailing disorder at the earliest possible time. We hope this study's aftermath will significantly impact the integrity and diversity of autism spectrum disorder.

Abstract 450: A targeted capture panel to identify translocations, copy number abnormalities, and mutations in multiple myeloma

Multiple myeloma (MM) is a genetically heterogeneous disease where risk stratification and outcomes are associated with translocations of the immunoglobulin (Ig) and MYC loci, copy number abnormalities and mutations. Therefore, we designed a comprehensive MM targeted sequencing panel (MM panel) to investigate the common genomic abnormalities and validated it against known standards. The MM panel includes targeted mutation and translocation panels encompassing ~ 990 kb and ~ 4.7 Mb respectively. The mutation panel includes exons of 228 genes and the translocation panel investigates the structural and copy number changes. The two panels are manufactured separately and combined in a 5:1 ratio to prevent over-sequencing of the larger translocation panel. To validate the MM panel, we performed targeted sequencing on 110 MM patient samples and compared the results to different orthogonal technologies. Libraries were prepared from the DNA extracted from CD138+ bone marrow cells and non-tumor tissue (peripheral blood or saliva) using the KAPA workflow. Following hybridization and amplification the libraries were sequenced using 75 bp paired end sequencing. Sequences were aligned to hg19 and mutations and translocations were identified using Strelka and Manta. Copy number was determined using the ratio of non-tumor to tumor reads in each targeted region. Data was further validated using clinical FISH (copy number and translocations), MLPA (copy number), known standards (mutations), or ddPCR (mutations). Canonical IgH translocations were detected in 33.6% of patients by sequencing which agreed with FISH except for one patient in which a t(11;14) was detected by FISH only. The overall sensitivity and specificity for translocation detection was 97.4% and 100%, respectively. Non-canonical translocations were detected in 14.5% of samples, 43% of which were to the MYC locus. MYC abnormalities were detected in 46.4% of samples. Copy number was determined by sequencing and MLPA for 22 regions that were directly comparable in 103 patient samples and the concordance between the technologies was R2=0.969. For the important prognostic regions, the concordance was R2=0.962 (CDKN2C), R2=0.986 (CKS1B), and R2=0.973 (TP53). Mutation detection validation was performed using samples with known variant allele frequencies (VAF) for common mutations. We were able to determine the sequencing VAF for 74 mutations across 5 samples with a concordance of R2=0.9849 between the expected and observed frequencies. The minimum detected VAF was 1.3% at an average depth of 891x. We also performed ddPCR on 6 patient samples with the common KRAS, NRAS and BRAF mutations with a VAF concordance of R2=0.9983. In summary, we have developed and validated a sequencing panel which is being deployed to clinical laboratories that is relevant to MM patient prognosis, risk stratification, and treatment.

Citation Format: Brian Andrew Walker, Aarif Ahsan, Parvathi Sudha, Tasneem Kausar, Sushmita Rane, Erin Flynt, Anjan Thakurta. A targeted capture panel to identify translocations, copy number abnormalities, and mutations in multiple myeloma [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 450.

170 Primary Breast Lymphoma-Mimicking Inflammatory Breast Disease: A Case Report

Primary breast lymphoma (PBL) is an unusual clinical entity accounting for 0.4–0.5% of all breast neoplasms. The usual presentation includes a painless palpable mass similar to that of breast carcinoma. Diffuse large B-cell lymphoma (DLBCL) is the most common identifiable type of PBL based on the histopathological examination.

We report an unusual case of 22 years old Bangladeshi woman presented with a 6-month history of a lump on left breast. Although the lump was initially small, it began a rapid growth after 4 months. The swelling was localized and did not show any skin involvement or discharge and as she didn’t have any positive familial history of breast carcinoma her primary attending physician diagnosed it as a case of breast abscess. When local incision and drainage proved ineffective, she was referred to us. After doing an immunohistochemistry from incisional biopsy the diagnosis was confirmed as Diffuse Large B-cell Lymphoma. The patient was treated initially by chemotherapy with CHOP therapy followed by wide local excision.

Early and accurate diagnosis of PBL is crucial for selecting the appropriate MDT treatment strategies to avert potentially harmful surgical interventions.

Comparative assessment of nutritive values and safety characteristics of bread sold in Bangladesh

Safe and good quality food products are essential to minimize human health risks and to facilitate business. The objective of this study was to assess the nutritional quality and defects of bread produced in Bangladesh. A total of sixty different types of bread sold in Bangladesh were collected by stratified random sampling and categorized as Brand shop (A), Local shop (B), and Street shop (C) bread. The samples were assessed for their nutritive values, microbiological contaminations, aflatoxins, heavy metals content, and sensory attributes. Nutrient composition and microbial quality were analyzed by using standard methods of the Association of Official Analytical Chemists (AOAC) and the American Public Health Association (APHA). High-Performance liquid chromatography method was used for aflatoxins determination. All categories of bread were low in macro and micronutrients (protein, fat, calcium, and iron) and high in sodium and alcoholic acidity. The heavy metals detected in bread (lead, cadmium, nickel and arsenic) were within the specification. Microbiological results showed that Salmonella spp. and Bacillus spp. were detected in many of the bread samples, whereas Escherichia coli and coliform were found in significant amounts in all categories of bread. Another important health concern that aflatoxins B1 and B2 were found in three bread samples of the local shops. In terms of sensory attributes, the brand shop bread had acquired the highest score for taste, texture, color, and overall acceptability. The study results showed that many of the bread samples were not suitable for healthy consumption, and special awareness should be taken for public health concern; it also warrants further research on safety and manufacturing practices of bread in Bangladesh.

Reassessment of Therapeutic Applications of Carbon Nanotubes: A Majestic and Futuristic Drug Carrier

Carbon nanotubes (CNTs) have been identified as one of the most advanced and versatile nanovectors, theranostics, and futuristic drug delivery tools for highly effective delivery of genes, drugs, and biomolecules, as well as for use in bioimaging and as biosensors. CNTs have drawn tremendous attention and interest from researchers worldwide in the past two decades owing to a number of unique characteristics including well defined physicochemical properties, large surface area, in addition to exclusive electrical and optical properties. Numerous recent literature related to the design and applications of CNTs were studied and summarized accordingly. Special emphasis was given for the applications of CNTs in drug targeting. Specific targeting of anticancer drugs such as cisplatin, doxorubicin, taxol, gemcitabine, and methotrexate, and delivery of small interfering RNA, micro-RNA, as well as plasmid DNA have been successfully assisted using CNTs. All the major applications of CNTs were summarized in detail with possible toxicity concerns associated with them. As far as their toxicity is concerned, it was noticed that the functionalized CNTs pose little toxicity and do not have immunogenic effects. In conclusion, CNTs showed great potential in developing a new generation of carriers for various drugs and related biomolecules. The application of CNTs ranges from physics to chemistry and now they are expanding their roles in the therapeutic drug delivery in the modern healthcare system. With applications in every imaginable route of administration, CNTs bring therapeutic benefits to society. The pharmaceutical, biopharmaceutical, pharmacokinetic, pharmacodynamic, and clinical efficacy of CNTs is explored in detail in this review.

Ubiquitin ligase SMURF2 enhances epidermal growth factor receptor stability and tyrosine-kinase inhibitor resistance

The discovery of activating epidermal growth factor receptor (EGFR) mutations spurred the use of EGFR tyrosine kinase inhibitors (TKIs), such as erlotinib, as the first-line treatment of lung cancers. We previously reported that differential degradation of TKI-sensitive (e.g. L858R) and resistant (T790M) EGFR mutants upon erlotinib treatment correlates with drug sensitivity. We also reported that SMAD ubiquitination regulatory factor 2 (SMURF2) ligase activity is important in stabilizing EGFR. However, the molecular mechanisms involved remain unclear. Here, using in vitro and in vivo ubiquitination assays, MS, and superresolution microscopy, we show SMURF2-EGFR functional interaction is important for EGFR stability and response to TKI. We demonstrate that L858R/T790M EGFR is preferentially stabilized by SMURF2-UBCH5 (an E3-E2)-mediated polyubiquitination. We identified four lysine residues as the sites of ubiquitination and showed that replacement of one of them with acetylation-mimicking glutamine increases the sensitivity of mutant EGFR to erlotinib-induced degradation. We show that SMURF2 extends membrane retention of EGF-bound EGFR, whereas SMURF2 knockdown increases receptor sorting to lysosomes. In lung cancer cell lines, SMURF2 overexpression increased EGFR levels, improving TKI tolerance, whereas SMURF2 knockdown decreased EGFR steady-state levels and sensitized lung cancer cells. Overall, we propose that SMURF2-mediated polyubiquitination of L858R/T790M EGFR competes with acetylation-mediated receptor internalization that correlates with enhanced receptor stability; therefore, disruption of the E3-E2 complex may be an attractive target to overcome TKI resistance.

Density of tobacco advertising around schools

BACKGROUND: Indonesia has the second highest smoking prevalence among adult males in the world, with over 61.4 million current smokers. However, there is no national regulation on outdoor tobacco advertising.OBJECTIVE: >To assess the density of outdoor tobacco advertising around schools in Semarang City, Indonesia.METHODS: We conducted geospatial analyses using buffer and hotspot analyses based on advertising and school data in ArcMap 10.6. We statistically tested the significance of different densities, including between 100 m and 100-300-m buffers from schools using Stata 15.1.RESULTS: We found a total of 3453 tobacco advertisements, of which 3026 (87%) were at least medium in size (1.3 m x l.9 m), and 2556 (74%) were within 300 m of schools. We also found hotspots with a 45% higher density of adverts within 100 m of schools (compared to within 100-300 m). A total of 378 schools (39%) were in these advertising hotspots.CONCLUSION: There was high density of outdoor tobacco advertising, with significant clusters in close proximity to schools in Semarang City. The policy implications of this are discussed.

Immunosuppressive milieu of high-risk localized prostate cancer

344

Background: The immune factors that modulate the aggressiveness of localized treatment-naïve prostate cancer remain poorly understood. Methods: Fresh tumor and peripheral blood were collected at the time of radical prostatectomy in patients with localized prostate cancer. We evaluated the immune cell composition of 22 patient samples employing multi-parametric flow cytometry. Samples were grouped by histological grade into intermediate (INTPCA) and high-grade (HIGHPCA) prostate cancers based on standard NCCN criteria and immune cell abundances were quantified by mean +/- SEM. Statistical significance was assessed using the Mann-Whitney test. Results: INTPCA and HIGHPCA tumors harbored a similar increase in CD8+ T cells ( p < 0.0005 and p < 0.05, respectively) and CD11b+CD68-CD16+ myeloid-derived cells (p < 0.05) relative to the peripheral blood. Other cell types were similarly decreased in both INTPCA and HIGHPCA, including CD11b+CD68+CD14+ ( p < 0.005 and p < 0.05, respectively). By contrast, regulatory T cells were the only cell type in our analysis to be uniquely enriched in HIGHPCA rather than INTPCA ( p < 0.05). The most unique feature found in phenotypic profiling of the immune repertoire of HIGHPCA relative to INTPCA was an increase in the immune inhibitory receptor ligand, PD-L1, in the tumor associated macrophages (CD11b+CD68+CD14+) compared to the periphery (p < 0.05). Conclusions: Collectively, our findings reveal that HIGHPCA harbors a distinct immunological landscape. Although effector CD8+ T cells are preferentially expressed in the tumor, these are met with an increased proportion of regulatory T cells as well as PD-L1 expressing macrophages that contribute to the inert tumor microenvironment. These are key features of aggressive prostate cancer that may serve as potential biomarkers and therapeutic targets.

Abstract 4563: Profiling the tumor immune microenvironment of adenocarcinoma and squamous cell NSCLC

The emergence of immune checkpoint inhibitors has changed the treatment paradigm for NSCLC. Recently, immunotherapy in combination with chemotherapy was shown to be a promising first-line treatment strategy for patients with squamous cell lung cancer, where targeted therapy has had little efficacy due to the pathological driver mutations for this disease being poorly understood. However, for both adenocarcinoma and squamous cell NSCLC, use of such immune checkpoint inhibitors has shown to improve the outcome for only a subset of patients with advanced or metastatic disease. Understanding the diversity in the tumor immune microenvironment will be critical to not only advance immune oncology research but to also determine potential clinical distinctions that dictate therapeutic response. Here, we take a multifaceted approach to compare the tumor immune microenvironments of over 50 patients diagnosed with either adenocarcinoma or squamous cell NSCLC. To this end, we performed a comprehensive multicolor flow cytometry analysis to compare tumor immune infiltrates and expression of suppressive markers to adjacent normal lung tissue as well as peripheral blood immune cells from the same patient. This analysis showed differences in the CD4+ and CD8+ T cell, CD19+ B cell, NK cell, and CD14+/CD16+ myeloid cell populations between the tumor and matched tissue and blood. These immune profiles were then compared between adenocarcinoma and squamous cell carcinoma subtypes as well as early versus late stage disease. We then integrated these findings with multiplexed immunofluorescence analysis on a panel of immune cell markers. Finally, 10x genomics single-cell RNA sequencing (scRNAseq) data were used to analyze single-cell transcriptomes from both adenocarcinoma and squamous cell lung tumors. Our result showed great heterogeneity of immune infiltrates across different patient samples, including different subtypes and different disease stages. This detailed comparative analysis will help us further understand the involvement of tumor infiltrating immune cells for different subtypes of lung cancer.

Citation Format: Kayla Harmeyer, Jiehui Deng, Suhagi Shah, Ece Bagdatlioglu, Aarif Ahsan, Christopher Reid, Aatish Thennavan, Charles Perou, Kwok-Kin Wong, Harvey Pass. Profiling the tumor immune microenvironment of adenocarcinoma and squamous cell NSCLC [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 4563.

RIP1 Kinase Drives Macrophage-Mediated Adaptive Immune Tolerance in Pancreatic Cancer

Pancreatic ductal adenocarcinoma (PDA) is characterized by immune tolerance and immunotherapeutic resistance. We discovered upregulation of receptor-interacting serine/threonine protein kinase 1 (RIP1) in tumor-associated macrophages (TAMs) in PDA. To study its role in oncogenic progression, we developed a selective small-molecule RIP1 inhibitor with high in vivo exposure. Targeting RIP1 reprogrammed TAMs toward an MHCII^hiTNFα⁺IFNγ⁺ immunogenic phenotype in a STAT1-dependent manner. RIP1 inhibition in TAMs resulted in cytotoxic T cell activation and T helper cell differentiation toward a mixed Th1/Th17 phenotype, leading to tumor immunity in mice and in organotypic models of human PDA. Targeting RIP1 synergized with PD1-and inducible co-stimulator-based immunotherapies. Tumor-promoting effects of RIP1 were independent of its co-association with RIP3. Collectively, our work describes RIP1 as a checkpoint kinase governing tumor immunity.

A Perspective on Low Molecular Weight Heparins in the Management of Thrombosis

The introduction of low molecular weight heparins has added a new dimension to the pharmacological management of thrombotic disorders. Because of different chemical and pharmacological characteristics, due to the manufacturing process, each LMWH should be considered as a distinct entitity and only be used for its given indication. A list of commercially available LMWHs is included. The mechanism of action of the LMWHs and their use in various disorders are discussed. Available laboratory tests for monitoring LMWHs are presented and their limitations pointed out.

ATM is the primary kinase responsible for phosphorylation of Hsp90α after ionizing radiation

Heat shock protein 90 is a chaperone that plays an essential role in the stabilization of a large number of signal transduction molecules, many of which are associated with oncogenesis. An Hsp90 isoform (Hsp90α) has been shown to be selectively phosphorylated on two N-terminal threonine residues (threonine 5 and 7) and is involved in the DNA damage response and apoptosis. However, the kinase that phosphorylates Hsp90α after ionizing radiation (IR) and its role in post-radiation DNA repair remains unclear. Inasmuch as several proteins of the DNA damage response machinery are Hsp90 clients, the functional consequences of Hsp90α phosphorylation following IR have implications for the design of novel radiosensitizing agents that specifically target the Hsp90α isoform. Here we show that ATM phosphorylates Hsp90α at the T5/7 residues immediately after IR. The kinetics of Hsp90α T5/7 phosphorylation correlate with the kinetics of H2AX S139 phosphorylation (γH2AX). Although Hsp90α is located in both the cytoplasm and nucleus, only nuclear Hsp90α is phosphorylated by ATM after IR. The siRNA mediated knockdown of Hsp90α sensitizes head and neck squamous cell carcinoma cells, lung cancer cells and lung fibroblasts to IR. Furthermore, MEF cells that are Hsp90α null have reduced levels of γH2AX indicating that Hsp90α is important for the formation of γH2AX. Thus, this study provides evidence that Hsp90α is a component of the signal transduction events mediated by ATM following IR, and that Hsp90α loss decreases γH2AX levels. This work supports additional investigation into Hsp90α T5/7 phosphorylation with the goal of developing targeted radiosensitizing therapies.

Differential protein stability of EGFR mutants determines responsiveness to tyrosine kinase inhibitors

Non-small cell lung cancer (NSCLC) patients carrying specific EGFR kinase activating mutations (L858R, delE746-A750) respond well to tyrosine kinase inhibitors (TKIs). However, drug resistance develops within a year. In about 50% of such patients, acquired drug resistance is attributed to the enrichment of a constitutively active point mutation within the EGFR kinase domain (T790M). To date, differential drug-binding and altered ATP affinities by EGFR mutants have been shown to be responsible for differential TKI response. As it has been reported that EGFR stability plays a role in the survival of EGFR driven cancers, we hypothesized that differential TKI-induced receptor degradation between the sensitive L858R and delE746-A750 and the resistant T790M may also play a role in drug responsiveness. To explore this, we have utilized an EGFR-null CHO overexpression system as well as NSCLC cell lines expressing various EGFR mutants and determined the effects of erlotinib treatment. We found that erlotinib inhibits EGFR phosphorylation in both TKI sensitive and resistant cells, but the protein half-lives of L858R and delE746-A750 were significantly shorter than L858R/T790M. Third generation EGFR kinase inhibitor (AZD9291) inhibits the growth of L858R/T790M-EGFR driven cells and also induces EGFR degradation. Erlotinib treatment induced polyubiquitination and proteasomal degradation, primarily in a c-CBL-independent manner, in TKI sensitive L858R and delE746-A750 mutants when compared to the L858R/T790M mutant, which correlated with drug sensitivity. These data suggest an additional mechanism of TKI resistance, and we postulate that agents that degrade L858R/T790M-EGFR protein may overcome TKI resistance.

Membrane Transition Temperature Determines Cisplatin Response

Cisplatin is a classical chemotherapeutic agent used in treating several forms of cancer including head and neck. However, cells develop resistance to the drug in some patients through a range of mechanisms, some of which are poorly understood. Using isolated plasma membrane vesicles as a model system, we present evidence suggesting that cisplatin induced resistance may be due to certain changes in the bio-physical properties of plasma membranes. Giant plasma membrane vesicles (GPMVs) isolated from cortical cytoskeleton exhibit a miscibility transition between a single liquid phase at high temperature and two distinct coexisting liquid phases at low temperature. The temperature at which this transition occurs is hypothesized to reflect the magnitude of membrane heterogeneity at physiological temperature. We find that addition of cisplatin to vesicles isolated from cisplatin-sensitive cells result in a lowering of this miscibility transition temperature, whereas in cisplatin-resistant cells such treatment does not affect the transition temperature. To explore if this is a cause or consequence of cisplatin resistance, we tested if addition of cisplatin in combination with agents that modulate GPMV transition temperatures can affect cisplatin sensitivity. We found that cells become more sensitive to cisplatin when isopropanol, an agent that lowers GPMV transition temperature, was combined with cisplatin. Conversely, cells became resistant to cisplatin when added in combination with menthol that raises GPMV transition temperatures. These data suggest that changes in plasma membrane heterogeneity augments or suppresses signaling events initiated in the plasma membranes that can determine response to cisplatin. We postulate that desired perturbations of membrane heterogeneity could provide an effective therapeutic strategy to overcome cisplatin resistance for certain patients.

Moving Beyond Cancer: Immediate Impact on-the Health-Related Quality of Life of Breast Cancer Patients After Mastectomy

During the last decade, survival rates for breast cancer have increased as a result of earlier detection and increased use of adjuvant therapy. Limited data exist on the post mastectomy quality of life in the process of transition from health to cancer in its different phases of treatment. The aim of current study was to evaluate the changes of health-related quality of life (HRQoL) after mastectomy and to measure their impression about future perspectives in Bangladeshi Breasts cancer patients. A group of 250 women with a diagnosis of primary breast cancer who was admitted in the department of surgical oncology in National Institute of Cancer Research and Hospital, Dhaka were enrolled in this study from January 2012 to March 2013. Two-point interview like pre(MI) and post mastectomy(M2) was taken using the structured questionnaire made by European Organization for Research and Treatment of Cancer (EORTC)- EORTC Q30 and BR23. The mean age of the patients was 44.7?9.87 years, 52.6% were locally advanced. HRQoL scores of breast cancer patients deteriorated after mastectomy, general features like presence of fatigability, nausea, apatite loss, sleeplessness and pain has got tremendous effect on the quality of life(p<.005). Financial difficulties and sleep disorders did not affect much. Four of the Global Health status/QOL parameters like physical functioning, role functioning, emotional functioning, cognitive functioning deteriorated but only physical functioning status affected significantly(p<0.005). Breast symptoms like body image problem, general breast symptoms like pain, arm swelling and sexual feeling affected their (HRQOL) after mastectomy. A diagnosis of cancer and associated treatments affects multiple domains of life. The complicated transitions between health, illness and living with cancer can often be challenged with a preoperative information for the patient confronted with breast cancer should include possible psychological effects of cancer diagnosis, surgery, and other treatment. Breast conservation particularly in the young group may give a better outcome in the treatment protocol of breast cancer patients.

Epidemiology, Risk Factors and Tumor Profiles of Breast Cancer in Bangladeshi underprivileged women

Similar to cancer statistics in developed countries, breast cancer is also the leading cause of cancer-related death in the women population of Bangladesh particularly the poor and underprivileged. The objective of this study was to study the socio-demography, tumor patterns and risk factors that affect these women from Dhaka and Bangladesh in general.

METHOD

This cross-sectional study involved 250 patients who presented to NICRH, Dhaka for treatment. These patients were interviewed, physically examined and vital information were gathered using approved questionnaires. Various personal, social, reproductive and tumor related factors were recorded and analyzed.

RESULT

The mean age of the study group was 44.7 years, standard deviation (SD) was 9.82 (range: 21-67), 87% have children, 57.2% were postmenopausal, 92% were housewives, 51.4% were illiterate, 62% attended 6 months after initiation of symptoms, 72% of the patients' yearly family income were less than US$1000/year. Almost 100% of the patients gave history of cooking from wooden fire source in the rural areas. In our study group, 79.7 percent women were within the group of BMI 20 kg/m2or more. Locally advanced breast cancer patients (T3 and T4) were 52.6%, axillary lymph node involvement was present in 80% of cases, 61.6 % patient received neoadjuvant chemotherapy. In the elderly group (above 40 years) Estrogen receptor was positive in 53.2% cases, 26.6% were Triple negative breast cancer patients.

CONCLUSION

Women with poor socio-economic status and have none or low educational level are often victims of late presentation and tend to have a higher stage at diagnosis. Poverty, literacy and assorted risk factors have influenced the outcome of breast cancer cases among Bangladeshi women.

Destabilization of the epidermal growth factor receptor (EGFR) by a peptide that inhibits EGFR binding to heat shock protein 90 and receptor dimerization

An eight-amino acid segment is known to be responsible for the marked difference in the rates of degradation of the EGF receptor (ErbB1) and ErbB2 upon treatment of cells with the Hsp90 inhibitor geldanamycin. We have scrambled the first six amino acids of this segment of the EGF receptor (EGFR), which lies in close association with the ATP binding cleft and the dimerization face. Scrambling these six amino acids markedly reduces EGFR stability, EGF-stimulated receptor dimerization, and autophosphorylation activity. Two peptides were synthesized as follows: one containing the wild-type sequence of the eight-amino acid segment, which we call Disruptin; and one with the scrambled sequence. Disruptin inhibits Hsp90 binding to the EGFR and causes slow degradation of the EGFR in two EGFR-dependent cancer cell lines, whereas the scrambled peptide is inactive. This effect is specific for EGFR versus other Hsp90 client proteins. In the presence of EGF, Disruptin, but not the scrambled peptide, inhibits EGFR dimerization and causes rapid degradation of the EGFR. In contrast to the Hsp90 inhibitor geldanamycin, Disruptin inhibits cancer cell growth by a nonapoptotic mechanism. Disruptin provides proof of concept for the development of a new class of anti-tumor drugs that specifically cause EGFR degradation.

Abstract 1028: Role of Hsp90 in the stability of EGFR from radiation and cisplatin-induced degradation

Heat-shock protein 90 (Hsp90) is an evolutionary conserved eukaryotic molecular chaperone that has a large number of clients including signaling molecules such as EGFR. Induction of Hsp90 upon cellular stress induced by radiation or chemotherapy can enhance stabilization of its clients which may lead to resistance to therapy and can often provide an environment for metastasis. Therefore, targeting Hsp90 has been shown to be a potential therapeutic approach to induce EGFR degradation and block metastatic spread. The aim of this study is to further understand the mechanism of Hsp90 induction and its post-translational modifications within cancer cells as well as its microenvironment and their significance in EGFR protein stability. We hypothesized that activation of Hsp90 upon cellular stress induced by radiation and chemotherapy provides stability to EGFR not only in cancer cells, but also in tumor-associated endothelial cells, which allows cancer cell survival and metastatic spread by increasing EGFR (and other clients) stability. Our preliminary data indicate that an enhancement in EGFR protein interaction with Hsp90 in both endothelial cells and head and neck cancer cell lines correlate with cell survival upon radiation or cisplatin treatment. Cisplatin treatment also caused an increase in Hsp90 activation as reflected by an increase in ATP binding activity. Increase in EGFR phosphorylation led to a decrease in its interaction with Hsp90. We also found that inhibition of Hsp90 activity reduced this interaction, which decreased EGFR half-life and promoted cell-death in cancer and endothelial cells. We are now extending our research efforts to understand the effects of radiation and cisplatin on the post-translational modifications of Hsp90 such as phosphorylation and its potential role in binding with EGFR. The long-term goal of this study is to develop a specific protein-protein interaction antagonist (PPI) to induce selective EGFR degradation and block the survival and metastatic spread regulated by EGFR.

Citation Format: Ameer L. Elaimy, Aarif Ahsan, Dipankar Ray, Theodore S. Lawrence, Mukesh K. Nyati. Role of Hsp90 in the stability of EGFR from radiation and cisplatin-induced degradation. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 1028. doi:10.1158/1538-7445.AM2013-1028

Effect of erlotinib on epidermal growth factor receptor and downstream signaling in oral cavity squamous cell carcinoma

BACKGROUND

The purpose of this study was to determine if there are differences in biomarker modulation and epidermal growth factor receptor (EGFR) degradation between the tumor and the normal mucosa after treatment with an EGFR inhibitor, erlotinib, in head and neck cancer.

METHODS

Patients with primary oral cavity squamous cell cancers received a course of erlotinib, 150 mg every day for 7 days before surgical resection. Tumor and normal mucosa biopsies were obtained both pre-erlotinib and post-erlotinib. Changes in known markers of EGFR activity (phospho, AKT, STAT3) were measured by immunoblotting, whereas changes in tissue distribution were analyzed by immunohistochemical analysis.

RESULTS

Twelve patients were enrolled; 7 had evaluable paired tumors and normal mucosa biopsies pretreatment and posttreatment. Expression of EGFR was higher in tumors compared to the normal mucosa (p = .005). Erlotinib administration was associated with marked inhibition of phosphorylated epidermal growth factor receptor (pEGFR) and reduction in total EGFR protein (p = .004, p = .007) in tumors, whereas there was heterogeneity in EGFR inhibition in the normal mucosa (p = .10 [pEGFR], and p = .07 [EGFR]). Reduced levels of pSrc and pSTAT3 and enhanced p27 levels were noted in tumors after erlotinib. Cell culture studies confirmed that EGFR is degraded in tumor cells after prolonged treatment with erlotinib.

CONCLUSION

Our results show that EGFR inhibition by erlotinib led to a marked reduction in EGFR protein levels in patients. Differential effects of erlotinib on tumors compared to the normal mucosa suggest there may be individual patient heterogeneity. These preliminary data suggest EGFR degradation should be further analyzed as a potential biomarker in selecting patients likely to benefit from EGFR inhibitors.

Role of NGOs and CBOs in Waste Management

BACKGROUND

Developing cities like Khulna, the third largest metropolitan city in Bangladesh, have now begun to confess the environmental and public health risks associated with uncontrolled dumping of solid wastes mainly due to the active participation of non-governmental organizations (NGOs) and community-based organizations (CBOs) in municipal solid waste (MSW) management.

METHODS

A survey was conducted to observe the present scenarios of secondary disposal site (SDS), ultimate disposal site (UDS), composting plants, medical wastes management and NGOs and CBOs MSW management activities.

RESULTS

A total of 22 NGOs and CBOs are involved in MSW management in 31 wards of Khulna City Corporation. About 9 to 12% of total generated wastes are collected by door-to-door collection system provided by mainly NGOs and CBOs using 71 non-motorized rickshaw vans. A major portion of collected wastes is disposed to the nearest SDS by these organizations and then transferred to UDS or to private low-lying lands from there by the city authority. A small portion of organic wastes is going to the composting plants of NGOs.

CONCLUSION

The participation of NGOs and CBOs has improved the overall MSW management system, especially waste collection process from sources and able to motivate the residents to store the waste properly and to keep clean the premises.

Early tumor progression associated with enhanced EGFR signaling with bortezomib, cetuximab, and radiotherapy for head and neck cancer

PURPOSE

A phase I clinical trial and molecular correlative studies were conducted to evaluate preclinical evidence for combinatorial activity of the proteasome inhibitor bortezomib, the epidermal growth factor receptor (EGFR) inhibitor cetuximab, and radiation therapy.

EXPERIMENTAL DESIGN

Patients with radiotherapy-naive stage IV or recurrent squamous cell carcinoma of the head and neck (SCCHN) were studied. Escalating doses of bortezomib (0.7, 1.0, and 1.3 mg/m²) were given intravenously twice weekly on days 1, 4, 8, and 11, every 21 days, with weekly cetuximab beginning 1 week prior and concurrently with intensity-modulated radiotherapy, delivered in 2 Gy fractions to 70 to 74 Gy. Molecular effects were examined in serial serum and SCCHN tumor specimens and the cell line UMSCC-1.

RESULTS

Seven patients were accrued before the study was terminated when five of six previously untreated patients with favorable prognosis oropharyngeal SCCHN progressed within 1 year (progression-free survival = 4.8 months; 95% CI, 2.6-6.9). Three patients each received bortezomib 0.7 or 1.0 mg/m², without dose-limiting toxicities; one patient treated at 1.3 mg/m² was taken off study due to recurring cetuximab infusion reaction and progressive disease (PD). Expected grade 3 toxicities included radiation mucositis (n = 4), dermatitis (n = 4), and rash (n = 1). SCCHN-related cytokines increased in serial serum specimens of patients developing PD (P = 0.029). Bortezomib antagonized cetuximab- and radiation-induced cytotoxicity, degradation of EGFR, and enhanced prosurvival signal pathway activation in SCCHN tumor biopsies and UMSCC-1.

CONCLUSIONS

Combining bortezomib with cetuximab and radiation therapy showed unexpected early progression, evidence for EGFR stabilization, increased prosurvival signaling, and SCCHN cytokine expression, warranting avoidance of this combination.

Abstract 509: Novel role of MeCP2 in response to EGFR targeted therapy

One of the targets towards the development of new agents to combat cancer is the inhibition of epidermal growth factor receptor (EGFR). A therapeutic antibody to EGFR, cetuximab, is seen to be effective in combination with cisplatin or radiation. However, only one out of four patients treated benefit from this therapy. It is therefore important to identify patients who can gain from this treatment. We hypothesize that through phosphoproteome analysis, we can identify alterations in novel signal transduction molecule(s) induced by cetuximab treatment in sensitive cell lines or TMA that will predict response to treatment. Phosphoproteomic changes upon cetuximab treatment in UMSCC-1 (cetuximab-responsive) and UMSCC-74B (cetuximab-non-responsive) cell lines using nonporous silica reverse-phase high performance liquid chromatography (NPS-RP-HPLC) were assessed. To confirm the results of phosphoproteomics data, three proteins that were seen to be affected in the sensitive cell line were investigated by immunoprecipitating total proteins followed by immunoblotting with phospho-specific antibodies. We found pharmacodynamic changes in 12 novel proteins upon cetuximab treatment in UMSCC-1 cell line. By Immunoblotting, we confirmed that these three proteins (methyl-CpG binding proteins) are indeed phosphorylated at serine, threonine and tyrosine sites. Cetuximab treatment in UMSCC-1, induced phosphorylation of NCoR1 and MeCP2 (which cause transcriptional repression) and decreased phosphorylation of MBD2 (which causes transcriptional activation), thus confirming the phosphoproteomic data. In contrast, the phosphoproteomics data in UMSCC-74B indicated either no effect or an opposing effect to that seen in the sensitive cells. These data suggest that we have a powerful strategy to identify novel phosphoproteins that are affected by EGFR inhibition and thus, novel biomarkers of response to cetuximab. These and additional biomarkers that we hope to discover will undergo rigorous in vitro and in vivo testing before employing them on TMA from xenografts.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 509.

Abstract 5451: Role of novel peptides targeting Hsp90-EGFR interaction to promote EGFR degradation and cisplatin cytotoxicity in head and neck cancer

Background: The eukaryotic heat shock protein 90 (Hsp90) is a ubiquitous chaperone protein that regulates many client proteins involved in signal transduction, cell cycle control and transcriptional regulation. These include the kinases implicated in tumorigenesis such as EGFR, Raf-1, ErbB-2, v-Src family kinases and Cdk4. Our previous data indicated that the interaction of Hsp90 with EGFR is critical for head and neck cancer cell survival upon treatment with cisplatin. We have also identified a potential region in EGFR that is involved in its interaction with Hsp90. We hypothesized that a small peptide analogous to this binding region of EGFR will competitively inhibit Hsp90 binding to EGFR, and therefore EGFR will not be protected from cisplatin induced degradation leading to cell death.

Methods and Results: Using Immunoblotting and clonogenic survival assays in eight head and neck squamous cancer cell lines we found that cisplatin-induced EGFR degradation significantly correlates with cytotoxicity. Immunoprecipitation of Hsp90 and/or EGFR showed that cisplatin induced EGFR degradation followed with its dissociation from Hsp90 in cisplatin sensitive cells. In contrary, cisplatin resistant cells showed a stabilized Hsp90-EGFR interaction and therefore EGFR was protected from cisplatin induced degradation. We also found that the Hsp90-EGFR interaction is reduced between EGFR mutants for the binding region of Hsp90 when compared to wild-type EGFR in Chinese hamster ovary cells (EGFR negative). Therefore, we design peptides targeting Hsp90-EGFR binding region. Importantly, we found that transfection of a novel peptide (8 amino acids) abolished the Hsp90-EGFR interaction in cisplatin resistant UMSCC-1 cells, promoted EGFR degradation and sensitized these cells to cisplatin in both culture and xenograft models. We further confirmed by using HIV-TAT-biotin derivative of this peptide that the peptide is getting internalized in cells and tumors. We also found the interaction of specific peptide with Hsp90.

Conclusions: Our results indicated that enhanced Hsp90-EGFR interaction is an adaptive response that can protect EGFR degradation induced by cisplatin treatment. We have identified a region in EGFR which is required for its interaction with Hsp90. Our data also indicated that using a novel peptide this interaction can be disrupted which promotes EGFR degradation and increases cytotoxicity in both culture and xenograft models. We are now investigating the role of this peptide in radiosensitization in head and neck carcinoma cell lines.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 5451.

Role of epidermal growth factor receptor degradation in cisplatin-induced cytotoxicity in head and neck cancer

Cisplatin and its analogues are the most commonly used agents in the treatment of head and neck squamous cell carcinoma. In this study, we investigated a possible role of epidermal growth factor (EGF) receptor (EGFR) phosphorylation and degradation in cisplatin-induced cytotoxicity. Cisplatin treatment led to an increase in initial EGFR phosphorylation at Y1045, the binding site of ubiquitin ligase, Casitas B-lineage lymphoma (c-Cbl), followed by ubiquitination in the relatively cisplatin-sensitive cell lines. However, cisplatin-resistant cell lines underwent minimal EGFR phosphorylation at the Y1045 site and minimal ubiquitination. We found that EGFR degradation in response to cisplatin was highly correlated with cytotoxicity in seven head and neck cancer cell lines. Pretreatment with EGF enhanced cisplatin-induced EGFR degradation and cytotoxicity, whereas erlotinib pretreatment blocked EGFR phosphorylation, degradation, and cisplatin-induced cytotoxicity. Expression of a mutant Y1045F EGFR, which is relatively resistant to c-Cbl-mediated degradation, in Chinese hamster ovary cells and the UMSCC11B human head and neck cancer cell line protected EGFR from cisplatin-induced degradation and enhanced cell survival compared with wild-type (WT) EGFR. Transfection of WT c-Cbl enhanced EGFR degradation and cisplatin-induced cytotoxicity compared with control vector. These results show that cisplatin-induced EGFR phosphorylation and subsequent ubiquitination and degradation is an important determinant of cisplatin sensitivity. Our findings suggest that treatment with an EGFR inhibitor before cisplatin would be antagonistic, as EGFR inhibition would protect EGFR from cisplatin-mediated phosphorylation and subsequent ubiquitination and degradation, which may explain the negative results of several recent clinical trials. Furthermore, they suggest that EGFR degradation is worth exploring as an early biomarker of response and as a target to improve outcome.

Sperm protein 17 is a novel marker for predicting cisplatin response in esophageal squamous cancer cell lines

Expression of sperm protein 17 (Sp17) mRNA has been reported in various malignancies. In an earlier study, we reported the upregulation of Sp17 transcripts in primary esophageal squamous cell carcinomas (ESCCs) using differential display and detected Sp17 transcripts in 86% of ESCCs by RT-PCR, whereas no transcripts were detected in the paired normal esophageal tissues. Herein we hypothesized that Sp17 might be used as a marker for detecting the response of anticancer therapies in ESCCs. Our results indicated that Sp17 protein levels in esophageal squamous cancer cell lines decreased in response to treatment with (i) the HSP90 activity inhibitor geldanamycin, (ii) the tyrosine kinase inhibitor erlotinib and (iii) cisplatin (chemotherapeutic agent commonly used in management of ESCC). In contrast, the Sp17 levels did not decrease in response to radiation therapy and treatment with the chemotherapeutic agent, gemcitabine. Further investigations showed that cisplatin induced decrease in Sp17 levels was due to transcriptional inhibition and cisplatin-resistant cell lines did not show this decrease in Sp17 levels in response to cisplatin treatment. In addition, we also carried our mass spectophotometric analysis to identify the binding partners of Sp17 to characterize its possible involvement in esophageal tumorigenesis and chemoresistance.

Staging of prostatic adenocarcinoma with radical prostatectomy specimens in Pakistan

OBJECTIVES

Data for pathological staging of radical prostatectomy specimens reported in the Section of Histopathology of a large tertiary care hospital in Pakistan were compared with sextant biopsy findings to determine whether clinically localized disease is actually localized pathologically.

DESIGN

A study was conducted of radical prostatectomy specimens reported in the Section of Histopathology from Jan 2001 to July 2008, with cases staged according to the pathologic TNM staging system. Other variables such as amount of tumor in prostatectomy specimens and lobes affected were also determined.

RESULTS

Out of 65 cases, 83.3% were clinical stage TIc. 29.2% were pT3a, 24.6% were pT3b and 3.1% were pT4. Therefore, in the majority of cases, disease was not localized to the prostate and perineurial invasion was seen in all. Comparison with biopsy results showed Gleason's grade to be altered in 20% cases.

CONCLUSIONS

The large majority of prostatic carcinomas in Pakistan are advanced cancers with pathologic stage more advanced than evident on clinical staging. On average, tumors involved 35-40% of the prostate with a particular preponderance in posterior lobes.

Role of cell cycle in epidermal growth factor receptor inhibitor-mediated radiosensitization

Epidermal growth factor receptor (EGFR) inhibitors are increasingly used in combination with radiotherapy in the treatment of various EGFR-overexpressing cancers. However, little is known about the effects of cell cycle status on EGFR inhibitor-mediated radiosensitization. Using EGFR-overexpressing A431 and UMSCC-1 cells in culture, we found that radiation activated the EGFR and extracellular signal-regulated kinase pathways in quiescent cells, leading to progression of cells from G(1) to S, but this activation and progression did not occur in proliferating cells. Inhibition of this activation blocked S-phase progression and protected quiescent cells from radiation-induced death. To determine if these effects were caused by EGFR expression, we transfected Chinese hamster ovary (CHO) cells, which lack EGFR expression, with EGFR expression vector. EGFR expressed in CHO cells also became activated in quiescent cells but not in proliferating cells after irradiation. Moreover, quiescent cells expressing EGFR underwent increased radiation-induced clonogenic death compared with both proliferating CHO cells expressing EGFR and quiescent wild-type CHO cells. Our data show that radiation-induced enhancement of cell death in quiescent cells involves activation of the EGFR and extracellular signal-regulated kinase pathways. Furthermore, they suggest that EGFR inhibitors may protect quiescent tumor cells, whereas radiosensitization of proliferating cells may be caused by downstream effects such as cell cycle redistribution. These findings emphasize the need for careful scheduling of treatment with the combination of EGFR inhibitors and radiation and suggest that EGFR inhibitors might best be given after radiation in order to optimize clinical outcome.

Endothelial nitric oxide synthase gene variants contribute to oxidative stress in COPD

Nitric oxide (NO) plays critical role in endothelial dysfunction and oxidative stress in COPD, pointing to the significance of endothelial nitric oxide synthase gene (eNOS) variants. We investigated the association of -786T/C, -922A/G, 4B/4A, and 894G/T polymorphisms of eNOS with the disease and its impact on nitrite and malonaldehyde levels in 190 COPD patients and 134 healthy controls, all smokers. The -786C, -922G and 4A alleles were significantly over-represented in patients (p=0.02, p=0.02, and p=0.03, respectively). The haplotypes, -786C:4A, 4A:894G, -786C:894G, and -786C:4A:894G were significantly over-represented in patients (p<0.0001, p =0.02, p=0.02, and p <0.0001, respectively), whereas, haplotypes, -786T:4B, 4B:894G, -786T:894G, and -786T:4B:894G were significantly under-represented in the patients (p<0.0001). The patients had significantly increased levels of nitrite (p=0.003) and malonaldehyde (p<0.0001). Combination of genotypes containing -786C and 4A alleles were greater in patients (p 0.05), and these combinations associated with decreased FEV1 value and nitrite level (p=0.03 and p=0.04, respectively) and with increased malonaldehyde levels (p=0.02). The eNOS -786C, -922G, and 4A alleles, these alleles associated haplotypes and genotype combinations were over-represented in patients. The variants and their combinations of four polymorphisms of eNOS contribute to disturbed pulmonary function and oxidative stress in COPD.

Ataxia Telangiectasia Mutated Down-regulates Phospho-Extracellular Signal-Regulated Kinase 1/2 via Activation of MKP-1 in Response to Radiation

Ataxia telangiectasia mutated (ATM) kinase plays a crucial role in the cellular response to DNA damage and in radiation resistance. Although much effort has focused on the relationship between ATM and other nuclear signal transducers, little is known about interactions between ATM and mitogenic signaling pathways. In this study, we show a novel relationship between ATM kinase and extracellular signal-regulated kinase 1/2 (ERK1/2), a key mitogenic stimulator. Activation of ATM by radiation down-regulates phospho-ERK1/2 and its downstream signaling via increased expression of mitogen-activated protein kinase phosphatase MKP-1 in both cell culture and tumor models. This dephosphorylation of ERK1/2 is independent of epidermal growth factor receptor (EGFR) activity and is associated with radioresistance. These findings show a new function for ATM in the control of mitogenic pathways affecting cell signaling and emphasize the key role of ATM in coordinating the cellular response to DNA damage.

Heterozygotes of NOS3 Polymorphisms Contribute to Reduced Nitrogen Oxides in High-Altitude Pulmonary Edema

STUDY OBJECTIVES

High-altitude pulmonary edema (HAPE), which develops on exertion under hypoxic conditions, aggravates due to endothelial dysfunction. Repeat events of the disorder suggests of genetic susceptibility. Endothelial nitric oxide synthase gene (NOS3), a regulator of vasodilation, has emerged as a strong candidate marker. In the present study, we investigated G894T, 27-base-pair 4b/4a (variable number of tandem repeat), -922A/G, and -786T/C polymorphisms of NOS3, individually or in combination, for an association with HAPE.

DESIGN

A cross-sectional case control study.

SETTINGS

Blood samples of HAPE-resistant lowlanders (HAPE-r) were obtained at sea level, and blood samples of patients with HAPE (HAPE-p) were obtained at Sonam Norboo Memorial Hospital, Leh, at 3,500 m.

PARTICIPANTS

The study groups consisted of 60 HAPE-r inducted two to three times to altitudes > 3,600 m; and 72 HAPE-p, who had HAPE on their first visit to high altitude.

RESULTS

Nitrogen oxides (NOx) at 77.9 +/- 28.6 micromol/L were significantly elevated in HAPE-r as compared to 42.39 +/- 12.93 micromol/L in HAPE-p (p < 0.0001). Genotype distribution of G894T and 4b/4a polymorphisms was significantly different in the two groups (p = 0.001 and 0.009, respectively). Haplotype analysis revealed -922A/G and -786T/C polymorphisms in complete linkage disequilibrium. The wild-type haplotypes G-b (G894T, 4b/4a), G-A (G894T, -922A/G), and G-b-A (G894T, 4b/4a, -922A/G) were significantly overrepresented in HAPE-r (p < 0.0001, p = 0.03, and p = 0.02, respectively). The heterozygote genotype combination GTba as compared to wild-type combination GGbb was significantly higher in HAPE-p (chi2 = 18.62, p = 0.00009; odds ratio, 7.20; 95% confidence interval, 2.82 to 18.38). The combination of four heterozygotes GTbaAGTC was overrepresented in HAPE-p (p = 0.04), whereas the wild-type genotype combination GGbbAATT was overrepresented in HAPE-r (p = 0.002). Furthermore, the GGbb combination correlated with significantly elevated NOx as compared to remaining combinations as a whole in both HAPE-r and HAPE-p (p = 0.01 and 0.004, respectively).

CONCLUSIONS

Reduced NOx and combination of heterozygotes associate with the susceptibility to HAPE. The study impels another step toward application of NOx as a diagnostic marker for HAPE. The NOS3 GTba and GTbaAGTC genotype combinations may find application as genetic markers for predicting the risk for HAPE.

Synthesis, conformational and pharmacological studies of glycosylated chimeric peptides of Met-enkephalin and FMRFa

Our previous study showed that a chimeric peptide of Met-enkephalin and FMRFamide, YFa (YGGFMKKKFMRFa) not only caused antinociception and potentiated morphine analgesia but also blocked the development of tolerance and physical dependence. In the continuation of that study three chimeric analogues of YFa, [Ser5]YFa, [O-Glu-Ser5]YFa and [O-Gal-Ser5]YFa, were synthesized. To increase the bioavailability and penetration of blood brain barrier (BBB), glycosylated analogues, [O-Glu-Ser5]YFa and [O-Gal-Ser5]YFa, have been synthesized by solid phase peptide synthesis by building block method using anomeric acetate activation method. Circular dichroism studies showed that all the three chimeric peptides are stable and have a propensity for adopting helical conformation in the presence of membrane mimicking solvent. In comparison of parent chimeric peptide YFa, helicity of [Ser5]YFa, [O-Glu-Ser5]YFa and [O-Gal-Ser5]YFa has decreased. Pharmacological studies using tail-flick latency in mice showed that [O-Glu-Ser5]YFa have increased analgesia and bioavailability in comparison of [O-Gal-Ser5]YFa and non-glycosylated analogue [Ser5]YFa. Exhibition of enhanced analgesia by [O-Glu-Ser5]YFa as compared to [O-Gal-Ser5]YFa seems to be due to preference of GLUT-1 transporter system for glucose.