Exosome: From biology to drug delivery

In recent years, different advancements have been observed in nanosized drug delivery systems. Factors such as stability, safety and targeting efficiency cause hindrances in the clinical translation of these synthetic nanocarriers. Therefore, researchers employed endogenous nanocarriers like exosomes as drug delivery vehicles that have an inherent ability to target more efficiently after appropriate functionalization and show higher biocompatibility and less immunogenicity and facilitate penetration through the biological barriers more quickly than the other available carriers. Exosomes are biologically derived lipid bilayer-enclosed nanosized extracellular vesicles (size ranges from 30 to 150 nm) secreted from both prokaryotic and eukaryotic cells and appears significantly in the extracellular space. These EVs (extracellular vesicles) can exist in different sources, including mammals, plants and microorganisms. Different advanced techniques have been introduced for the isolation of exosomes to overcome the existing barriers present with conventional methods. Extensive research on the application of exosomes in therapeutic delivery for treating various diseases related to central nervous system, bone, cancer, skin, etc. has been employed. Several studies are on different stages of clinical trials, and many exosomes patents have been registered.

The G-protein-coupled estrogen receptor, a gene co-expressed with ERα in breast tumors, is regulated by estrogen-ERα signalling in ERα positive breast cancer cells

GPER is a seven transmembrane G-protein-coupled estrogen receptor that mediates rapid estrogen actions. Large volumes of data have revealed its association with clinicopathological variables in breast tumors, role in epidermal growth factor (EGF)-like effects of estrogen, potential as a therapeutic target or a prognostic marker, and involvement in endocrine resistance in the face of tamoxifen agonism. GPER cross-talks with estrogen receptor alpha (ERα) in cell culture models implicating its role the physiology of normal or transformed mammary epithelial cells. However, discrepancies in the literature have obfuscated the nature of their relationship, its significance, and the underlying mechanism. The purpose of this study was to assess the relationship between GPER, and ERα in breast tumors, to understand the mechanistic basis, and to gauge its clinical significance. We mined The Cancer Genome Atlas (TCGA)-BRCA data to examine the relationship between GPER and ERα expression. GPER mRNA, and protein expression were analyzed in ERα-positive or -negative breast tumors from two independent cohorts using immunohistochemistry, western blotting, or RT-qPCR. The Kaplan-Meier Plotter (KM) was employed for survival analysis. The influence of estrogen in vivo was studied by examining GPER expression levels in estrus or diestrus mouse mammary tissues, and the impact of 17β-estradiol (E2) administration in juvenile or adult mice. The effect of E2, or propylpyrazoletriol (PPT, an ERα agonist) stimulation on GPER expression was studied in MCF-7 and T47D cells, with or without tamoxifen or ERα knockdown. ERα-binding to the GPER locus was explored by analysing ChIP-seq data (ERP000380), in silico prediction of estrogen response elements, and chromatin immunoprecipitation (ChIP) assay. Clinical data revealed significant positive association between GPER and ERα expression in breast tumors. The median GPER expression in ERα-positive tumors was significantly higher than ERα-negative tumors. High GPER expression was significantly associated with longer overall survival (OS) of patients with ERα-positive tumors. In vivo experiments showed a positive effect of E2 on GPER expression. E2 induced GPER expression in MCF-7 and T47D cells; an effect mimicked by PPT. Tamoxifen or ERα-knockdown blocked the induction of GPER. Estrogen-mediated induction was associated with increased ERα occupancy in the upstream region of GPER. Furthermore, treatment with 17β-estradiol or PPT significantly reduced the IC₅₀ of the GPER agonist (G1)-mediated loss of MCF-7 or T47D cell viability. In conclusion, GPER is positively associated with ERα in breast tumors, and induced by estrogen-ERα signalling axis. Estrogen-mediated induction of GPER makes the cells more responsive to GPER ligands. More in-depth studies are warranted to establish the significance of GPER-ERα co-expression, and their interplay in breast tumor development, progression, and treatment.

Concordance of Frozen Section Diagnosis of Epithelial Ovarian Neoplasm and Discussing the Diagnostic Pitfalls: An Institutional Experience

Background  Ovarian neoplasm is the third most common malignancy in Indian women. Intraoperative diagnosis becomes the critical guiding tool for the surgeons to take the decisions on the extent of surgery specially when preserving fertility has to be considered. Aims and Objective  The aim of this study is to evaluate the concordance of intraoperative diagnosis of frozen section (IFS) of ovarian epithelial neoplasm at our institute and to review and discuss the diagnostic pitfalls along with the review of literature. Materials and Methods  Data were archived from departmental record and the detailed clinical data of the patients were retrieved from hospital record system. The discordant cases were reviewed again in an attempt to address the pitfalls. Statistical Analysis  Diagnostic accuracy, sensitivity, specificity, and positive and negative predictive value of IFS of ovarian neoplasm were analyzed. Results  The overall frozen section diagnosis was concordant with final histopathology in 36 out of 44 cases (81%). The sensitivity of IFS diagnosis was found to be 100% for benign and borderline tumors, whereas 88.9% for malignant epithelial tumors, but the correctness of diagnosis is high only for benign and malignant tumors (high positive predictive value) in compared with borderline ones. The diagnostic pitfalls were identified individually in discordant cases. Conclusion  An accurate interpretation of IFS in ovarian epithelial malignancy can be achieved in benign and malignant cases, but limited in borderline tumors. Awareness of the artifacts and the limitations in mind and the IFS diagnosis can be of great help for proper management of the ovarian neoplasm.

Urinary Metabolomics Identified Metabolic Perturbations Associated with Gutka, a Smokeless Form of Tobacco

Gutka, a form of smokeless tobacco, is widely used in the Indian subcontinent and in other regions of South Asia. Smokeless tobacco exposure is most likely to increase the incidence of oral cancer in the Indian population, and metabolic changes are a hallmark of cancer. The development of biomarkers for early detection and better prevention measures for smokeless tobacco users at risk of oral cancer can be aided by studying urinary metabolomics and offering insight into altered metabolic profiles. This study aimed to investigate urine metabolic alterations among smokeless tobacco users using targeted LC-ESI-MS/MS metabolomics approaches to better understand the effects of smokeless tobacco on human metabolism. Smokeless tobacco users' specific urinary metabolomics signatures were extracted using univariate, multivariate analysis and machine learning methods. Statistical analysis identified 30 urine metabolites significantly associated with metabolomic alterations in humans who chew smokeless tobacco. Receiver operator characteristic (ROC) curve analysis evidenced the 5 most discriminatory metabolites from each approach that could differentiate between smokeless tobacco users and controls with higher sensitivity and specificity. An analysis of multiple-metabolite machine learning models and single-metabolite ROC curves revealed discriminatory metabolites capable of distinguishing smokeless tobacco users from nonusers more effectively with higher sensitivity and specificity. Furthermore, metabolic pathway analysis depicted several dysregulated pathways in smokeless tobacco users, including arginine biosynthesis, beta-alanine metabolism, TCA cycle, etc. This study devised a novel strategy to identify exposure biomarkers among smokeless tobacco users by combining metabolomics and machine learning algorithms.

Small vessel childhood primary angiitis of the central nervous system with positive anti-glial fibrillary acidic protein antibodies: a case report and review of literature

BACKGROUND

Small vessel childhood primary angiitis of the central nervous system (SV-cPACNS) is a rare disease characterized by inflammation within small vessels such as arterioles or capillaries.

CASE PRESENTATION

We report a case of SV-cPACNS in an 8-year-old boy confirmed by brain biopsy. This patient was also incidentally found to have anti-glial fibrillary acidic protein (GFAP) antibodies in the cerebrospinal fluid (CSF) but had no evidence of antibody-mediated disease on brain biopsy. A literature review highlighted the rarity of SV-cPACNS and found no prior reports of CSF GFAP-associated SV-cPACNS in the pediatric age group.

CONCLUSION

We present the first case of biopsy proven SV-cPACNS vasculitis associated with an incidental finding of CSF GFAP antibodies. The GFAP antibodies are likely a clinically insignificant bystander in this case and possibly in other diseases with CNS inflammation. Further research is needed to determine the clinical significance of newer CSF autoantibodies such as anti-GFAP before they are used for medical decision-making in pediatrics.

Insight on Cardiac Chronobiology and Latest Developments of Chronotherapeutic Antihypertensive Interventions for Better Clinical Outcomes

Cardiac circadian rhythms are an important regulator of body functions, including cardiac activities and blood pressure. Disturbance of circadian rhythm is known to trigger and aggravate various cardiovascular diseases. Thus, modulating the circadian rhythm can be used as a therapeutic approach to cardiovascular diseases. Through this work, we intend to discuss the current understanding of cardiac circadian rhythms, in terms of quantifiable parameters like BP and HR. We also elaborate on the molecular regulators and the molecular cascades along with their specific genetic aspects involved in modulating circadian rhythms, with specific reference to cardiovascular health and cardiovascular diseases. Along with this, we also presented the latest pharmacogenomic and metabolomics markers involved in chronobiological control of the cardiovascular system along with their possible utility in cardiovascular disease diagnosis and therapeutics. Finally, we reviewed the current expert opinions on chronotherapeutic approaches for utilizing the conventional as well as the new pharmacological molecules for antihypertensive chronotherapy.

Variant influenza: connecting the missing dots

BACKGROUND

In June 2009, the World Health Organization declared a new pandemic, the 2009 swine influenza pandemic (swine flu). The symptoms of the swine flu pandemic causing strain were comparable to most of the symptoms noted by seasonal influenza.

AREA COVERED

Zoonotic viruses that caused the swine flu pandemic and its preventive measures.

EXPERT OPINION

As per Centers for Disease Control and Prevention (CDC), the clinical manifestations in humans produced by the 2009 H1N1 'swine flu' virus were equivalent to the manifestations caused by related flu strains. The H1N1 vaccination was the most successful prophylactic measure since it prevented the virus from spreading and reduced the intensity and consequences of the pandemic. Despite the availability of therapeutics, the ongoing evolution and appearance of new strains have made it difficult to develop effective vaccines and therapies. Currently, the CDC recommends yearly flu immunization for those aged 6 months and above. The lessons learned from the A/2009/H1N1 pandemic in 2009 indicated that readiness of mankind toward new illnesses caused by mutant viral subtypes that leap from animals to people must be maintained.

Analysis of Biochemical and Hematological Parameters During the First and Second Wave of SARS-CoV-2 Infection among North-East Indian Cancer Patients

Introduction: SARS-CoV-2 (COVID-19) affects respiratory airways as well as the kidneys, hearts etc. This study aims to demonstrate the impact of COVID-19 infection on biochemical and hematological parameters in cancer patients of North-East India. Methods: The study includes biochemical parameters for 907 and hematological parameters for 1103 cancer patients who were tested for COVID-19 between 1st June 2020 and 1st June 2021. All the data were analyzed by the statistical software SPSS (ver20). Results: AST (p = 0.023), GGT (p = 0.026) and Urea (p = 0.004) significantly increased in COVID-19 positive cancer patients compared to negative cancer patients. Eosinophils (p=0.01), eosinophils absolute (p=0.01), monocyte (p=0.04) and MCHC (p=0.01) were significantly decreased in COVID-19 positive cancer patients compared to negative. Various biochemical and haematological parameters analysed in our study were found to be altered between the COVID-19 positive and negative group but their association was not found to be statistically significant. Conclusion: We conclude that in cancer patients of North-East India, significant alterations of biochemical and hematological parameters AST, GGT, Urea, Eosinophils, eosinophils absolute, monocyte and MCHC were found in COVID-19 positive cancer patients compared to negative cancer patients.

Histopathological study of round cell tumors of the head and neck region in a tertiary care hospital: A retrospective study

Background: Small round cell tumors are heterogeneous, highly aggressive malignant tumors occuring in unusual sites with overlapping clinical and radiographic features.  Their diagnosis is challenging using conventional histopathologic approaches because of indistinct features in small biopsy samples and hence immunohistochemistry is a must. This study was undertaken to evaluate the pattern, common types, age, sex distribution of round cell tumors of the head and neck region and to obtain morphological immunohistochemistry correlation. Material and Methods: It is a retrospective study of 99 cases which fulfilled the inclusion criteria. Paraffin blocks were retrieved and were reviewed by two independent expert observers and immunohistochemistry was repeated whenever necessary. Results: Final diagnosis was given based on the immunohistochemistry pattern and our study showed 8 spectrums of round cell tumours. Lymphoma was the most common followed by neuroendocrine carcinoma. Most B-cell Non Hodgkin Lymphoma, undifferentiated carcinomas and Neuroendocrine carcinomas were observed in older group whereas, Ewing sarcoma /Primitive Neuro Ectodermal Tumour and T cell NHL were seen more in younger group. According to sex wise distribution, 70 (70.7%) cases were male and 29 (29.3%) females with male to female ratio of 2.4:1. Conclusions: Round cell tumors can occur at any sites of the head and neck region. There are certain morphologic features for each tumor which may help the surgical pathologist to come to a probable diagnosis in addition to careful search of the detailed history, location of tumor, presentation, radiological findings and ultimately correlating with immunohistochemistry.

Salivary microbial dysbiosis may predict lung adenocarcinoma: A pilot study

BACKGROUND

Adenocarcinoma is a more common type of Non-small cell lung cancer (NSCLC). Lung cancer showed a statistically significant increment in the Kamrup Urban district of Assam, Tripura, Sikkim, and Manipur of India. The goal of our pilot study is to identify non-invasive microbial biomarkers to detect lung adenocarcinoma (LAC).

MATERIAL AND METHODS

DNA extraction from saliva samples of five LAC patients and five healthy controls was performed by Qiagen DNeasy blood and tissue kit using Lysozyme (3mg/ml) treatment. 16S rRNA genes of distinct regions (V3-V4) were amplified from saliva DNA by PCR. Paired-end sequencing targeting the V3-V4 region of the 16S rRNA gene has been performed on the Illumina MiSeq platform. Raw sequences were analyzed using the QIIME(Quantitative Insights Into Microbial Ecology) software package.

RESULTS

Our preliminary results showed that Rothia mucilaginosa, Veillonella dispar, Prevotella melaninogenica, Prevotella pallens, Prevotella copri, Haemophilus parainfluenzae, Neisseria bacilliformis and Aggregatibacter segnis were significantly elevated in saliva of LAC which may serve as potential non-invasive biomarkers for LAC detection. Functional prediction analysis showed that bacterial genes involved in glycosyltransferase, peptidases, amino sugar, and nucleotide sugar metabolism, starch and sucrose metabolism were significantly enriched in LAC.

CONCLUSION

These salivary bacteria may contribute to the development of LAC by increasing expression of glycosyltransferase and peptidases. However to understand their role in pathobiology, studies are required to perform in large cohort.

BMP4 enhances anoikis resistance and chemoresistance of breast cancer cells through canonical BMP signaling

Bone morphogenetic proteins (BMPs) regulate cell fate during development and mediate cancer progression. In this study, we investigated the role of BMP4 in proliferation, anoikis resistance, metastatic migration, and drug resistance of breast cancer cells. We utilized breast cancer cell lines and clinical samples representing different subtypes to understand the functional effect of BMP4 on breast cancer. The BMP pathway was inhibited with the small molecule inhibitor LDN193189 hydrochloride (LDN). BMP4 signaling enhanced the expression of stem cell genes CD44, ALDH1A3, anti-apoptotic gene BCL2 and promoted anoikis resistance in MDA-MB-231 breast cancer cells. BMP4 enhanced self-renewal and chemoresistance in MDA-MB-231 by upregulating Notch signaling while LDN treatment abrogated anoikis resistance and proliferation of anoikis resistant breast cancer cells in the osteogenic microenvironment. Conversely, BMP4 downregulated proliferation, colony-forming ability, and suppressed anoikis resistance in MCF7 and SkBR3 cells, while LDN treatment promoted tumor spheroid formation and growth. These findings indicate that BMP4 has a context-dependent role in breast cancer. Further, our data with MDA-MB-231 cells representing triple-negative breast cancer suggest that BMP inhibition might impair its metastatic spread and colonization.

Noncontrast MRI Protocol for Selected Pediatric Pituitary Endocrinopathies: A Procedure with High Diagnostic Yield and Potential to Reduce Anesthesia and Gadolinium-Based Contrast Exposure

BACKGROUND AND PURPOSE

Although many pediatric neuroradiology practices empirically use noncontrast brain and pituitary MR imaging for evaluation of growth hormone deficiency, central precocious puberty, and short stature, there are currently insufficient published data to support this practice in an evidence-based fashion. Therefore, the use of contrast-enhanced MR imaging for all pediatric pituitary endocrinopathies remains widespread. We evaluated whether noncontrast MR imaging has adequate diagnostic yield for the evaluation of pediatric growth hormone deficiency, central precocious puberty, and short stature.

MATERIALS AND METHODS

Pituitary MR imaging studies obtained for growth hormone deficiency, central precocious puberty, or short stature in patients 0-18 years of age from 2010 to 2019 were analyzed. Separate blinded review of noncontrast images in cases with abnormalities on the original radiology report was performed by 2 subspecialty-trained pediatric neuroradiologists, with discrepancies resolved by consensus.

RESULTS

Of the 134/442 MR imaging studies obtained for growth hormone deficiency, central precocious puberty, or short stature with hypothalamic-pituitary region abnormalities, there was 70% concordance with the original reports on blinded review of noncontrast images. Twenty-two of 40 discrepancies were deemed unrelated to the indication, and 9 cases originally interpreted as possible microadenoma were read as having normal findings on blinded review. Only 9 of 40 discrepancies required contrast for further characterization.

CONCLUSIONS

In our study, most relevant radiologic findings in patients with growth hormone deficiency, central precocious puberty, and short stature were detectable without contrast, providing evidence that contrast can be avoided in routine MR imaging evaluation of these indications. We propose a "rapid noncontrast pituitary" MR imaging protocol for pediatric patients presenting with growth hormone deficiency, central precocious puberty, or short stature, which may increase efficiency and decrease contrast and anesthesia exposure.

Fungal profile and antifungal susceptibility pattern of candidiasis in esophageal cancer patients

Aim

This study was carried out to determine the fungal profile and antifungal susceptibility pattern in the brushing samples of candidiasis in patients with carcinoma of esophagus.

Materials and Methods

The study was carried out in the Departments of Microbiology and Surgical Oncology of a regional cancer center from January 2017 to December 2017. Samples were collected under all aseptic precaution and Clinical Laboratory Standards Institute guidelines 2017 was followed for antifungal susceptibility testing.

Results

A total of 132 endoscopy brushing samples were collected from histological proven esophageal cancer patients and processed for fungal culture. Of which, 75 (56.81%) samples showed culture positivity and were recruited. Candida albicans in 40 (53.33%), Candida krusei in 25 (33.33%), Candida tropicalis in 7 (9.33%), and Candida glabrata in 3 (4%) patients were seen. Among the 40 C. albicans isolates, all were sensitive to caspofungin - 40 (100%), 34 (85%) showed sensitivity to fluconazole, and 32 (80%) showed sensitivity to flucytosine. C. krusei and C. tropicalis showed 100% sensitivity to caspofungin, and C. glabrata isolates showed 100% resistance to caspofungin and 80% resistance to Amphotericin B.

Conclusion

The present study revealed the emergence of multidrug-resistant, nonalbicans Candida isolates in cancer esophagus patients with candidiasis in northeast India.

RUNX1T1, a potential prognostic marker in breast cancer, is co-ordinately expressed with ERα, and regulated by estrogen receptor signalling in breast cancer cells

BACKGROUND

RUNX1T1 is extensively studied in the context of AML1-RUNX1T1 fusion protein in acute myeloid leukemia. Little is known about the function of RUNX1T1 itself, although data on its function and regulation have begun to emerge from clinical, and in vitro studies. It is a putative tumor suppressor, whose expression is altered in a variety of solid tumors. Recently, reduced expression of RUNX1T1 in triple-negative breast tumors, and its influence on prognosis was reported.

METHODS AND RESULTS

The Kaplan-Meier Plotter online tool was used to study the relationship between RUNX1T1 expression and survival of breast cancer patients. High RUNX1T1 expression was associated with longer overall survival (OS), relapse-free survival (RFS) and distant metastasis free survival (DMFS). RUNX1T1 expression positively and negatively influenced OS of patients with ERα-positive and ERα-negative breast tumors, respectively. It was also associated with prolonged RFS, and DMFS in tamoxifen-treated patients. Expression of RUNX1T1 and ERα mRNA was analyzed in 40 breast tumor samples, and breast cancer cell lines using RT-PCR. TCGA-BRCA data was mined to study the relationship between RUNX1T1 and ERα mRNA expression. ERα-positive breast tumors showed significantly higher RUNX1T1 mRNA expression compared to ERα-negative tumors. RUNX1T1 mRNA expression was analyzed by qRT-PCR in MCF-7 or T47D cells, which were treated with 17β-estradiol, or the ERα agonist PPT, alone or in combination with 4-hydroxytamoxifen. Effect of ERα knockdown was also investigated. Results indicate that estrogen downmodulated RUNX1T1 mRNA expression via ERα.

CONCLUSION

Higher expression of RUNX1T1 in breast tumors is associated with favourable prognosis. RUNX1T1 and ERα show co-ordinated expression in breast tumors, and breast cancer cell lines. Estrogen-ERα signalling downmodulates the expression of RUNX1T1 mRNA in ERα-positive breast cancer cells. In-depth investigations on the interaction between RUNX1T1 and ERα are warranted to unravel the role and relevance of RUNX1T1 in breast cancer.

Geometry encoded functional programming of tumor homing peptides for targeted drug delivery

Poly-peptide molecules have shown promising applications in drug delivery and tumor targeting. A series of tumor homing peptides were designed by exhaustively sampling low energy geometrical basins of amino acids at specific sites of a peptide molecule to induce a conformational lock. This peptide library was pruned to a limited set of eight molecules, employing electrostatic interactions, docking, and molecular dynamics simulations. These designed and optimized peptides were synthesized and tested on various cell lines, including breast cancer (MDA-MB-231), cervical cancer (HeLa), osteosarcoma (U2-OS), and non-cancerous mammary epithelial cells (MCF-10A) using confocal microscopy and flow cytometry. Peptides show differential uptake in cancerous MDA-MB-231, HeLa, U2-OS, and non-cancerous MCF-10A cells. Confocal imaging verified their ability to penetrate even in 3D tumorospheres of MDA-MB-231 cells. Further, experiments of mitochondrial membrane potential depolarization and Caspase-3 activation confirmed that their cytotoxic effects are by apoptosis. Homing ability of the designed peptides in in vivo system and fluorescence imaging with clinical samples of human origin have further confirmed that the in vitro studies are qualitatively identical and quantitatively comparable in their ability to selectively recognize tumor cells. Overall, we present a roadmap for the functional programming of peptide-based homing and penetrating molecules that can perform selective tumor targeting.

Therapeutic nanostructures and nanotoxicity

Nanotechnology, with its continuous advancement, leads to the development of nanoscale-level therapeutics to mitigate many complex diseases. This results in the emergence of numerous novel nanomaterials and its composite products into the market such as liposome, polymeric nanoparticles, dendrimers, and nanostructured lipid carrier. However, their application is always determined by a high benefit to risk ratio. Very few research have been done on the toxicity assessment of nanoparticles in the biological system; therefore, the limited knowledge regarding the toxicity profile of nanotherapeutics is available leading to the ignorance of its side effects. Nanoparticles can distribute in the whole body through translocating in the bloodstream by crossing membrane barriers efficiently and shows effect in organs and tissues at cellular and molecular levels. The interaction of nanoparticle with cell may consequences into nanotoxicity. The narrow size distribution, large surface area to mass ratio and surface properties of nanoparticle are significantly associated with nanotoxicity. Nanoparticles can enter into the tissue and cell by invading the membranes and cause cellular injury as well as toxicity. Therefore, the exploration of mechanisms of nanotoxicity has prime importance now a day. The toxicity assessment should be an integral part of the development of nanotherapeutics using various toxicity evaluation models. This review has focused on the exploration of different nanostructures for therapeutic delivery system along with its physicochemical characteristics responsible for adverse effects on human biology, various toxicity evaluation models, and environmental and regulatory hurdles.

Bacteriological Profile and Antibiotic Sensitivity Pattern of Clinical Isolates in a Tertiary Cancer Care Center in the Northeast India

Background  This study was performed to determine the bacteriological profile and antibiotic sensitivity pattern of culture samples of patients with cancer at our institute. The study was undertaken to formulate an antibiotic policy for the treatment of infection in these patients. Materials and Methods  The study was performed in the Department of Microbiology of a regional cancer center during the period from January 2017 to December 2017. Samples were collected under all aseptic precaution, and they were processed as per the Clinical and Laboratory Standard Institute Guideline 2017. Results  A total of 464 clinical samples (urine, blood, sputum, pus, etc.) were collected and processed for culture, of which 198 (42.67%) samples showed culture positive that were identified as per standard recommended procedures and antibiotic susceptibility testing was performed on isolates as per the Clinical Laboratory Standard Institute guidelines 2017. Escherichia coli (48), Staphylococcus aureus, (45) Klebsiella pneumoniae (52), Coagulase-negative Staphylococcus (17), and Pseudomonas aeruginosa (15) were most commonly encountered. Of the 132 Gram-negative isolates, 101 (76.5%) were extended-spectrum β-lactamase producers. Among the 45 staphylococcal isolates, 18 (40%) were methicillin-resistant S . aureus. Conclusion  The present study reveals microbiological profile in patients attending our cancer institute.

Study of Serum CEA and Ca 19.9 in Esophageal Squamous Carcinoma and ROC Curve Analysis

Background: There are very few studies on the comparative diagnostic value of CEA and Ca19.9 in esophageal squamous cell carcinoma (ESCC).Aims and objectives: The aim of the present study was to access the clinical relevance of CEA and CA19.9 in ESCC and to determine whether combined use of these marker could improve diagnostic sensitivity and specificity. Material and Method: Venous blood Samples were collected from total 68 individuals, divided into two categories, group 1 includes 18 healthy individuals and group 2 includes 50 patients with already diagnosed cases of ESCC prior to any treatment. Tests were performed to estimate the value of CEA and Ca19.9. Different statistical analysis has been performed to derive a clinically meaningful value.Results: The mean serum CEA and CA 19.9 levels and also the ratio of CEA/Ca19.9 were higher in patients with ESCC than healthy subjects. In ESCC, the optimal combination of sensitivity and specificity for CEA were determined as 48% and 94% and for CA19.9 were determined as 76% and 72% respectively, whereas combined analysis of CEA/CA19.9 were lower than individual value in patients. Over all accuracy rate was better with CA19. The diagnostic power of CEA and CA19-9 as a screening test for ESCC were assessed by ROC curve analysis. The cut-off value for CEA and CA19-9 in ESCC were found to be 2.9 2 ng/ml and 7.4 ng/ml and were found to be above the cut-off value in 25 (50%) and 42 (84%) of the patients with ESCC respectively.Conclusion: The results of our study indicated that serum CA19.9 has a higher positivity than serum CEA in esophageal cancer. The combined use of CA19-9 and CEA (ratio) could not increase the diagnostic sensitivity in esophageal cancers in our study.

Experience with Orbital Tumors from a Tertiary Cancer Centre of North East India: A Pathology Perspective

Background  The orbit is an anatomically complex structure comprising the globe, extraocular muscles, fat, vascular, nervous, glandular, and connective tissues. A wide variety of neoplasms can arise from different orbital structures, which can create a diagnostic challenge to the pathologists. No formal study has been conducted in this regard in North East India. Aim and Objectives  This article aims to document the pattern and prevalence of orbital tumors in our institute and assess the utility of histopathological examination (HPE) and immunohistochemistry (IHC) in the precise diagnosis of these neoplasms. Materials and Methods  A retrospective analysis of orbital tumors was performed over a period of 5 years from 2013 to 2018 in the department of pathology at a tertiary cancer center of North East India following all the guidelines of the institutional ethics committee. Results  A total of 35 cases of orbital neoplasms, evaluated by HPE and IHC, were found, all of them being malignant tumors. The age range was 4 months to 85 years. Male to female ratio was 1.5:1. The most common tumor found was lymphoma, accounting for 10 cases (28.6%), all of which were non-Hodgkin lymphoma (NHL). All these cases except one occurred in adults, thus making it the most common tumor in adults in this study. Diffuse large B cell lymphoma, not otherwise specified, was the most common NHL, followed by follicular lymphoma, mature T cell NHL, extranodal marginal zone lymphoma, and B cell lymphoblastic lymphoma. Rhabdomyosarcoma and poorly differentiated/undifferentiated carcinoma jointly were the second most common tumors, totaling seven cases (21.21%) each. This was followed by melanoma (three cases), myeloid sarcoma (three cases), Ewing sarcoma/peripheral neuroectodermal tumor (PNET) (three cases), neuroblastoma (one case), and angiosarcoma (one case). Among these, rhabdomyosarcoma, granulocytic sarcoma, Ewing sarcoma/PNET, and neuroblastoma exclusively troubled the children. IHC markers including the lymphoma panel, and soft tissue ones were crucial in the precise diagnosis of the neoplasms encountered. Conclusion  A variety of malignant orbital tumors may be seen in clinical practice. Management of these tumors requires a multidisciplinary approach. HPE in conjunction with IHC evaluation is of utmost importance in the veracious recognition of orbital tumors for their proper management.

Diffuse Leptomeningeal Glioneuronal Tumor of Childhood

Diffuse leptomeningeal glioneuronal tumor is a newly defined entity under the neuronal and mixed neuronal-glial tumors category in the 2016 World Health Organization classification of brain tumors. In this series, we report clinical, radiologic, and histologic findings in 7 cases of diffuse leptomeningeal glioneuronal tumor. Our cases and literature review indicate that the most characteristic imaging finding is diffuse intracranial and intraspinal nodular leptomeningeal thickening and enhancement. This is often associated with small cyst-like, nonenhancing lesions. It should be noted that tumors sometimes bear nontypical features, for example, presenting as a solitary spinal cord mass without leptomeningeal involvement or with a dominant intracranial mass. In children with characteristic imaging findings and without clinical features of infection, the radiologist has an opportunity to promptly raise the possibility of diffuse leptomeningeal glioneuronal tumor, and thereby, affect streamlined diagnostic evaluation.

Dysbiosis of salivary microbiome and cytokines influence oral squamous cell carcinoma through inflammation

Advanced combinatorial treatments of surgery, chemotherapy, and radiotherapy do not have any effect on the enhancement of a 5-year survival rate of oral squamous cell carcinoma (OSCC). The discovery of early diagnostic non-invasive biomarkers is required to improve the survival rate of OSCC patients. Recently, it has been reported that oral microbiome has a significant contribution to the development of OSCC. Oral microbiome induces inflammatory response through the production of cytokines and chemokines that enhances tumor cell proliferation and survival. The study aims to develop saliva-based oral microbiome and cytokine biomarker panel that screen OSCC patients based on the level of the microbiome and cytokine differences. We compared the oral microbiome signatures and cytokine level in the saliva of OSCC patients and healthy individuals by 16S rRNA gene sequencing targeting the V3/V4 region using the MiSeq platform and cytokine assay, respectively. The higher abundance of Prevotella melaninogenica, Fusobacterium sp., Veillonella parvula, Porphyromonas endodontalis, Prevotella pallens, Dialister, Streptococcus anginosus, Prevotella nigrescens, Campylobacter ureolyticus, Prevotella nanceiensis, Peptostreptococcus anaerobius and significant elevation of IL-8, IL-6, TNF-α, GM-CSF, and IFN-γ in the saliva of patients having OSCC. Oncobacteria such as S. anginosus, V. parvula, P. endodontalis, and P. anaerobius may contribute to the development of OSCC by increasing inflammation via increased expression of inflammatory cytokines such as IL-6, IL-8, TNF-α, IFN-γ, and GM-CSF. These oncobacteria and cytokines panels could potentially be used as a non-invasive biomarker in clinical practice for more efficient screening and early detection of OSCC patients.

Clinicopathological and immunohistochemical characteristics of breast cancer patients from Northeast India with special reference to triple negative breast cancer: A prospective study

BACKGROUND

Molecular pathogenesis of Triple-negative breast cancer (TNBC) is inconclusively documented from resource limited countries and hence there is a lack of available targeted therapy for clinical interventions. Compared to other breast cancer subtypes, TNBC is more aggressive, higher recurrence rate, and higher prevalence in younger premenopausal women. Sporadic literature indicates predominance of TNBC in all reported breast cancer cases from Northeast India.

AIM

This study was conducted to evaluate the candidature of panel of key molecular markers involved in the development and progression of TNBC for prognosis and futuristic tailored targeted therapy.

MATERIALS AND METHODS

We analyzed the clinicopathological characterized and immunohistochemically screened the differential expression of key molecular markers involved in the development and progression of in TNBC cases vis-a-vis non-TNBC and autopsy-based control samples.

RESULTS

TNBC tends to display at an early reproductive age and is more aggressive in nature. Further, the differential expression of 2 specific markers viz., epidermal growth factor receptor (EGFR) and FolR1 was higher in TNBC cases compared to controls and non-TNBC (both in terms of susceptibility and specificity), clinical staging in TNBC cases (severity) and mortality (outcome). Although Ki67 and vascular endothelial growth factor expression also correlated with severity and outcome of the disease but their differences in non-TNBC cases were not significantly differentiable compared to TNBC.

CONCLUSIONS

The study indicates that EGFR and FolR1 could serve as useful biomarkers to determine TNBC prognosis. Further studies will be needed to evaluate EGFR and Folate pathways in order to screen out the molecular targets which may be meaningfully used for clinical stratification, intervention, and treatment.

Nose to brain delivery of antiretroviral drugs in the treatment of neuroAIDS

NeuroAIDS (Neuro Acquired Immunodeficiency Syndrome) or HIV (Human Immunodeficiency Virus) associated neuronal abnormality is continuing to be a significant health issue among AIDS patients even under the treatment of combined antiretroviral therapy (cART). Injury and damage to neurons of the brain are the prime causes of neuroAIDS, which happens due to the ingress of HIV by direct permeation across the blood-brain barrier (BBB) or else via peripherally infected macrophage into the central nervous system (CNS). The BBB performs as a stringent barricade for the delivery of therapeutics drugs. The intranasal route of drug administration exhibits as a non-invasive technique to bypass the BBB for the delivery of antiretroviral drugs and other active pharmaceutical ingredients inside the brain and CNS. This method is fruitful for the drugs that are unable to invade the BBB to show its action in the CNS and thus erase the demand of systemic delivery and thereby shrink systemic side effects. Drug delivery from the nose to the brain/CNS takes very less time through both olfactory and trigeminal nerves. Intranasal delivery does not require the involvement of any receptor as it occurs by an extracellular route. Nose to brain delivery also involves nasal associated lymphatic tissues (NALT) and deep cervical lymph nodes. However, very little research has been done to explore the utility of nose to brain delivery of antiretroviral drugs in the treatment of neuroAIDS. This review focuses on the potential of nasal route for the effective delivery of antiretroviral nanoformulations directly from nose to the brain.

Alterations of salivary microbial community associated with oropharyngeal and hypopharyngeal squamous cell carcinoma patients

The highest number (35.1% of global incident cases) of new oropharyngeal (OP) and hypopharyngeal (HP) cancer cases was reported in South-Central Asia. The highest incidence of HP cancer in India was reported in East Khasi Hills District of Meghalaya, Aizawl District of Mizoram, and Kamrup Urban District of Assam. HP and OP cancer showed the highest mortality rate, worst prognoses and the highest rate of nodal metastases and distant metastases. Thus, research is required to detect specific biomarkers for early prevention and diagnosis for these cancers. Oral microbiome signatures in saliva are considered as a potential diagnostic biomarker for OP and HP cancer. Bacterial profile alterations in OP and HP cancer have not been reported in India population, to establish the association of oral bacteria in the progression of OP and HP cancer; we studied bacterial communities in saliva of eight OP and seven HP cancer patients as compared to healthy controls using 16S rRNA V3-V4 region sequencing. The higher abundance of Haemophilus parainfluenzae, Haemophilus influenzae and Prevotella copri and lower abundance of Rothia mucilaginosa, Aggregatibacter segnis, Veillonella dispar, Prevotella nanceiensis, Rothia aeria, Capnocytophaga ochracea, Neisseria bacilliformis, Prevotella nigrescens and Selenomonas noxia in saliva of OP and HP cancer patients may be considered as a non-invasive diagnostic biomarker for OP and HP cancer patients. Streptococcus anginosus may be considered as a non-invasive diagnostic biomarker for OP cancer patients only. Therefore, evaluation of salivary microbial biomarkers may be informative to understand the pathobiology and carcinogenesis of OP and HP cancer.

Clinico-epidemiological features and response in childhood acute lymphoblastic leukemia at regional cancer center of Northeast India

Introduction:

Acute lymphoblastic leukemia (ALL) comprises 19.3% of all childhood cancers in Northeast India.

Methods:

We analyzed clinicoepidemiological features and early response to the treatment of all the cases of childhood ALL (age <15 years) diagnosed and treated at Dr. B Borooah Cancer Institute over 1 year.

Results:

Of 52 eligible cases, 69% were male (male:female ratio of 2.2:1) and the mean age was 7.1 years. Thirty-three children (63%) had baseline white blood cell count ≥20 × 10⁹/L. Precursor B-cell was most the common subtype seen in 61% of children. Seven cases (14%) had high-risk (HR) cytogenetics, with t (9,22) being the most common one. Male sex and HR cytogenetics were significantly associated with poor early responses.

Conclusion:

ALL is a common childhood malignancy with high cure rates. However, poor socioeconomic status and the presence of higher proportions of disease-related factors lead to poor outcome in this part of the country.

Human Parechovirus Meningoencephalitis: Neuroimaging in the Era of Polymerase Chain Reaction-Based Testing

Human parechovirus infection is an increasingly recognized cause of neonatal meningoencephalitis. We describe characteristic clinical features and brain MR imaging abnormalities of human parechovirus meningoencephalitis in 6 infants. When corroborated by increasingly available polymerase chain reaction-based testing of the CSF, the distinctive MR imaging appearance may yield a specific diagnosis that obviates costly and time-consuming further clinical evaluation. In our study, infants with human parechovirus presented in the first 35 days of life with seizures, irritability, and sepsis. MR imaging consistently demonstrated low diffusivity within the thalami, corpus callosum, and subcortical white matter with a frontoparietal predominance. T1 and T2 shortening connoting white matter injury along the deep medullary veins suggests venous ischemia as an alternative potential pathogenetic mechanism to direct neuroaxonal injury.

MYC Regulates the HIF2α Stemness Pathway via Nanog and Sox2 to Maintain Self-Renewal in Cancer Stem Cells versus Non-Stem Cancer Cells

Cancer stem cells (CSC) maintain both undifferentiated self-renewing CSCs and differentiated, non-self-renewing non-CSCs through cellular division. However, molecular mechanisms that maintain self-renewal in CSCs versus non-CSCs are not yet clear. Here, we report that in a transgenic mouse model of MYC-induced T-cell leukemia, MYC, maintains self-renewal in Sca1⁺ CSCs versus Sca-1^- non-CSCs. MYC preferentially bound to the promoter and activated hypoxia-inducible factor-2α (HIF2α) in Sca-1⁺ cells only. Furthermore, the reprogramming factors, Nanog and Sox2, facilitated MYC regulation of HIF2α in Sca-1⁺ versus Sca-1^- cells. Reduced expression of HIF2α inhibited the self-renewal of Sca-1⁺ cells; this effect was blocked through suppression of ROS by N-acetyl cysteine or the knockdown of p53, Nanog, or Sox2. Similar results were seen in ABCG2⁺ CSCs versus ABCG2^- non-CSCs from primary human T-cell lymphoma. Thus, MYC maintains self-renewal exclusively in CSCs by selectively binding to the promoter and activating the HIF2α stemness pathway. Identification of this stemness pathway as a unique CSC determinant may have significant therapeutic implications. SIGNIFICANCE: These findings show that the HIF2α stemness pathway maintains leukemic stem cells downstream of MYC in human and mouse T-cell leukemias. GRAPHICAL ABSTRACT: http://cancerres.aacrjournals.org/content/canres/79/16/4015/F1.large.jpg.

Pattern of T-cell Non-Hodgkin's Lymphoma in a Tertiary Care Center in North East India

Context: The non-Hodgkin's lymphomas (NHLs) are lymphoid neoplasms that arise primarily in the lymph nodes. They are classified into B-cell, T-cell, and natural killer cell types and are subtyped on the basis of morphologic and immunohistochemical studies. T-cell neoplasms are clonal tumors of mature and immature T-cells at various stages of differentiation. T-cell lymphoma is common in Asia compared to Europe and America. The pattern and prevalence of T-cell lymphoma in India are, however, different from that of other Asian countries. Aims: The main aim of this study is to analyze the prevalence and pattern of T-cell NHL in North East India, as less number of studies have been carried out in this part of the country. Settings and Design: A 5-year retrospective study (2012–2016) was carried out in our institute, which is a regional cancer center located in North East India. Materials and Methods: Five-year records of previously diagnosed cases were obtained, and then the hematoxylin- and eosin-stained sections and the immunohistochemistry slides were reviewed and studied. Results: A total number of 294 cases of NHL were reviewed in the study period. Seventy-one cases were found to be of T-cell NHL type which comprised 24% of the total NHL. Peripheral T-cell lymphoma not-otherwise specified (PTCL-NOS) (62%) was the most common followed by anaplastic large cell lymphoma (27%). T-lymphoblastic lymphoma (7%) was common in children and young adults. Conclusion: PTCL-(NOS) was found to be the most common T-cell lymphoma. Treatment of most of the cases was by chemotherapy using the cyclophosphamide, doxorubicin, vincristine, and prednisone regimen.

Abstract 3342: A novel indigenous knowledge system based approach to study cancer health disparities in rural population of North East India

Background: India's North East is an economically deprived and politically unstable region inhabited by diverse groups of indigenous people. The incidence of cancer (mainly oral) is unusually high in the region. Through our KaviKrishna telemedicine care (www.kavikrishnalab.org) with collaboration of Thoreau Lab for Global Health (www.thoreaulab.org) we have initiated a longitudinal study in the greater Sualkuchi (50,000 population) area to identify different elements that underlie cancer health disparities. Specially, we wanted to develop an indigenous knowledge system (IKS) based approach (1) as an analytical tool to study cancer health disparities. IKS may be defined as a knowledge-emergence mechanism as a result of non-linear communication between an individual and his/her culture (1).

Methods: An IKS-based experimental approach was developed as follows. First, we identified 45 cancer patients (mostly oral cancer, age group- 30-65 years; 60% male) living in Sualkuchi. Second, we mapped out each patient’s social network/support system through regular home visit, interviews, focused group discussion, and visits to attending doctors. Third, one group of patients (n= 30 out of 45 patients) and relatives were empowered with basic knowledge about their disease and the available treatments needs through regular focused group meetings. After three months, we repeated interviews/group discussion to find whether they communicated their knowledge/experience to generate an IKS-based system (1). The data were then fed into the IKS-network analysis tool, which we developed partly, based on hub-system (3) and thematic network based approach (3). 10 patients from urban area served as a control population.

Results: We found that 40 out of 45 patients find it extremely difficult to navigate the complex cancer care system due to lack of communication with treating oncologists/surgeons as compared to urban patients. 15 patients discontinued follow up visit mainly for this reason alone. 25 patients showed evidence of communicating through a pre-existing IKS-based system. Surprisingly, these 25 patients were positively responding to our care services/group discussion and becoming emotionally and psychologically strong towards managing their self-care.

Conclusion: Our study indicates that lack of communication is a major cause of cancer health disparity. An IKS based approach may enhance communication, and contribute to cancer care in rural India.

1. Bikul Das. Globalization and Emerging Opportunities of Indigenous Culture. 2003. (www.academia.edu/ 7882695).2. Anita Kothari et al. Using an integrated knowledge translation approach to build a public health research agenda. Healthy Research Policy and Systems, 2014. (PMID: 24475759).3. Jennifer Attride-stirling: Thematic networks: an analytic tool for qualitative research. 2001. Qualitative Research.

Note: This abstract was not presented at the meeting.

Citation Format: Lekhika Pathak, Bidisha Pal, Tutumoni Baishya, Anupam Sarma, Bikul Das. A novel indigenous knowledge system based approach to study cancer health disparities in rural population of North East India [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 3342.

Assessment and clinicopathological correlation of matrix metalloproteinase 9 expression in nasopharyngeal carcinoma

INTRODUCTION

Nasopharyngeal cancer is not a common disease in most parts of the world. In India also, nasopharyngeal carcinoma (NPC) is not a common cancer, except for the Northeastern region of the country. Expression of matrix metalloproteinase 9 (MMP9) in the tumor cells is related to tumor invasion and metastasis. The aim of the present study is to analyze the expression of MMP9 in NPC and evaluate its prognostic implications.

MATERIALS AND METHODS

A total of 32 histologically confirmed tissue samples of NPC were examined by immunohistochemical staining to assess the expression of MMP9. Clinicopathological parameters and levels of MMP9 expression in the tumor tissue were analyzed using Chi-square test. Survival analysis was done using the Kaplan-Meier method and was compared using log-rank test. P <0.05 was considered statistically significant.

RESULTS

Of the 32 tissue samples of NPC, 23 (71.9%) were male and 9 (28.1%) were female. 7 (21.9%) patients presented in T1 Stage, 8 (25.0%) in T2, 12 (37.5%) in T3, and 5 (15.6%) in T4 Stages, respectively. 29 (90.6%) patients presented with lymph node metastasis. MMP9 expression level was significantly correlated with patient's age (P = 0.033), tumor histology (P = 0.017), tumor stage (P = 0.021), and lymph node metastasis (P = 0.011). The 5-year overall survival is higher for low-level expression as compared to high-level expression of MMP9 (P = 0.046).

CONCLUSION

MMP9 is an important prognostic factor for NPC. High expression of MMP9 is associated with cervical lymph nodes metastasis and poor survival outcome.

Causes of Treatment Abandonment of Pediatric Cancer Patients – Experience in a Regional Cancer Centre in North East India

Introduction:

Refusal and abandonment of treatment is often considered as an important reason for poor survival of pediatric cancer patients in developing and underdeveloped countries. In this study we analyze the factors responsible for treatment abandonment and refusal in a Regional Cancer Centre (RCC) in North East India.

Material and Methods:

All histopathologically or cytologically confirmed cases of childhood cancer from below 15 years of age registered from 1st April, 2010 to 31st March, 2017 were included in this study. Parents or caregivers were interviewed thoroughly and a questionnaire was filled up for analysis of demographic and socio-economic factors. Modified Kuppuswamy scale was used to measure socioeconomic status.

Results:

Of 592 patients 161 (27.1%) abandoned therapy and 23 (3.9%) refused treatment. Factors associated with abandonment of treatment included: lower risk if residing in urban areas (Odds ratio [OR] = 0.8333, 95% CI 0.565-1.228; P=0.36) and higher risk with maternal education less than secondary school (OR = 1.357; 95%CI: 0.553-3.326; P=0.505). Low socioeconomic status and age >5yrs were also associated with abandonment of treatment. In a binary logistic regression analysis, male sex [Odds Ratio (OR) = 0.701; 95% CI 0.48-1.01; P=0.062] have lowest risk of abandoning treatment with trend to statistical significance.

Conclusion:

There is a need for proper definition of the problem of childhood cancer patients so that appropriate policy can be introduced to improve survival by improving treatment compliance.

Formulation by Design (FbD) approach to develop Tenofovir Disoproxil Fumarate loaded Nanostructured Lipid Carriers (NLCs) for the aptness of nose to brain delivery

The objective of the present investigation was to optimize and develop Tenofovir Disoproxil Fumarate (TDF) loaded Nanostrucrured Lipid Carriers (NLCs) with Compritol 888 ATO as solid lipid and oleic acid as liquid lipid by modified emulsion solvent diffusion method using Central Composite design (CCD). Three independent variables viz., Lipid to Drug ratio (A), Aqueous phase pH (B) and Sonication time (min) (C) were taken to investigate their effect on dependent variables viz., particle size (nm) (R1), PDI (R2) and % Entrapment Efficiency (%EE) (R3). Optimized formula of NLC was selected from the design space which was further optimized by changing the surfactants quantity. NLCs were evaluated for physicochemical, morphological, solid state characterization, and in-vitro dissolution in PBS pH 6.4, PBS 7.4 and ACSF. The average particle size was found to be 94.7 ± 15.70 nm with PDI of 0.380 ± 0.024 and 134.3 ± 9.71 nm with PDI of 0.358 ± 0.038 respectively for T4 and T5 NLC formulation. The zeta potential value of -17. ± 3.87 mV and -17.17 ± 1.05 mV and %EE of 35.5 ± 1.04 % and 34.2 ± 2.78 %. Overall, the above finding shows promising results in the area of developing non-invasive intranasal route as an alternative to oral route for brain delivery.  Keywords: Central composite design, Intranasal, Neuro-AIDS, CNS targeting.

Oxidative Stress and Cardiovascular Risk in Type 1 Diabetes Mellitus: Insights From the DCCT/EDIC Study

Background

Hyperglycemia leading to increased oxidative stress is implicated in the increased risk for the development of macrovascular and microvascular complications in patients with type 1 diabetes mellitus.

Methods and Results

A random subcohort of 349 participants was selected from the DCCT / EDIC (Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications) cohort. This included 320 controls and 29 cardiovascular disease cases that were augmented with 98 additional known cases to yield a case cohort of 447 participants (320 controls, 127 cases). Biosamples from DCCT baseline, year 1, and closeout of DCCT , and 1 to 2 years post‐ DCCT ( EDIC years 1 and 2) were measured for markers of oxidative stress, including plasma myeloperoxidase, paraoxonase activity, urinary F 2α isoprostanes, and its metabolite, 2,3 dinor‐8 iso prostaglandin F 2α . Following adjustment for glycated hemoblobin and weighting the observations inversely proportional to the sampling selection probabilities, higher paraoxonase activity, reflective of antioxidant activity, and 2,3 dinor‐8 iso prostaglandin F 2α , an oxidative marker, were significantly associated with lower risk of cardiovascular disease (−4.5% risk for 10% higher paraoxonase, P <0.003; −5.3% risk for 10% higher 2,3 dinor‐8 iso prostaglandin F 2α , P =0.0092). In contrast, the oxidative markers myeloperoxidase and F 2α isoprostanes were not significantly associated with cardiovascular disease after adjustment for glycated hemoblobin. There were no significant differences between DCCT intensive and conventional treatment groups in the change in all biomarkers across time segments.

Conclusions

Heightened antioxidant activity (rather than diminished oxidative stress markers) is associated with lower cardiovascular disease risk in type 1 diabetes mellitus, but these biomarkers did not change over time with intensification of glycemic control.

Clinical Trial Registration

URL : https://www.clinicaltrials.gov . Unique identifiers: NCT 00360815 and NCT 00360893.

Nano-ART and NeuroAIDS

Human immunodeficiency virus (HIV) is a neurotropic virus that enters the central nervous system (CNS) early in the course of infection. Although highly active antiretroviral therapy (HAART) has resulted in remarkable decline in the morbidity and mortality in AIDS patients, controlling HIV infections still remains a global health priority. HIV access to the CNS serves as the natural viral preserve because most antiretroviral (ARV) drugs possess inadequate or zero delivery across the brain barriers. The structure of the blood-brain barrier (BBB), the presence of efflux pumps, and the expression of metabolic enzymes pose hurdles for ARV drug-brain entry. Thus, development of target-specific, effective, safe, and controllable drug delivery approach is an important health priority for global elimination of AIDS progression. Nanoformulations can circumvent the BBB to improve CNS-directed drug delivery by affecting such pumps and enzymes. Alternatively, they can be optimized to affect their size, shape, and protein and lipid coatings to facilitate drug uptake, release, and ingress across the barrier. Improved drug delivery to the CNS would affect pharmacokinetic and drug biodistribution properties. This review focuses on how nanotechnology can serve to improve the delivery of antiretroviral medicines, termed NanoART, across the BBB and affect the biodistribution and clinical benefit for NeuroAIDS.

Abstract 42: MYC through HIF-2α regulates the altruistic stemness program in human leukemia stem cells

Leukemia is hierarchically organized into two distinct population of cancer cells, cancer stem cells (CSCs) and non-stem cancer cells (NSCC). Numerous studies suggest that CSCs may express embryonic stem (ES) cells related stemness genes including Nanog, Sox-2, and Oct-4. However, potential cell surface markers that could specifically enrich the leukemia stem cell (LSC) subfraction based on the expression of these stemness genes have not yet been identified. Previously, we reported that ABCG2, a drug efflux pump, could enrich a subpopulation of cells exhibiting very high level of Nanog, Sox-2, and Oct-4 in ES cells. Additionally, these ABCG2+ ES cells also exhibited high HIF-2α, a transcription factor, which in cooperation with MYC-regulated both Nanog and Sox-2. In addition to these features, ABCG2+ cells demonstrated highly cytoprotective altruistic behavior by secreting high levels of glutathione. In the present study, we evaluated whether ABCG2+ subfraction of human LSCs exhibits high level of Nanog, Sox2, and Oct4. We also investigated the altruistic behavior of the LSCs, a potential novel mechanism of drug resistance and disease relapse.

Methods: ABCG2+ cells from cervical lymph node and peripheral blood of T- cell acute lymphoblastic lymphoma/leukemia (T-ALL) and chronic myeloid leukemia (CML) patients (n=12) were enriched using immunomagnetic sorting. These cells were then expanded and used for different experiments including flow cytometry, ChiP on ChiP assay, in vivo transplantation assay, and siRNA inhibition treatment, to demonstrate the role of HIF-2α and MYC in regulating the altruistic stemness program in human LSCs.

Results: We were able to enrich ABCG2+ cell subfraction from human T-ALL (n=5) and CML (n=7) patients exhibiting high levels of stemness genes such as Nanog, Sox-2, and Oct-4 in addition to MYC and HIF-2α. Higher engraftment potential was observed in ABCG2+ cells in comparison to ABCG2- cells as indicated by in vivo transplantation assay in NOD/SCID mice. The inhibition of stemness genes Nanog and Sox2 by siRNA gene silencing led to the loss of expression of MYC and HIF-2α, indicating that these genes are regulated MYC and HIF-2α. We then investigated the altruistic stemness phenotype of the ABCG2+ cells by studying the distinct molecular signature of MYC binding to HIF-2α in these cells. siRNA HIF-2α treatment led to ABCG2+ cell loss of proliferative capacity and reduced GSH levels, suggesting reduction of cytoprotective altruistic behavior in vitro. Additionally, siRNA HIF-2α treated ABCG2+ cells, when injected in mice, exhibited increased survival. Importantly, treatment of ABCG2+ cell harboring mice with FM19G11, a HIF inhibitor, led to marked loss in the secondary engraftment in NOD/SCID mice, thus indicating loss of ABCG2+ cell self-renewal capacity. Then we found that siRNA MYC inhibition led to loss of HIF-2α expression, suggesting that MYC might be regulating HIF-2α mediated altruistic stemness program in the ABCG2+ cells.

Conclusion: To summarize, we found that ABCG2 is an excellent marker to enrich the LSC subfraction having high expression of stemness genes. The ABCG2+ LSCs exhibit altruistic stemness phenotype that includes high secretion of GSH and the distinct binding of MYC to HIF-2a, Sox2, and Nanog. Thus, we now report that a subfraction of LSC could also be enriched such that it exhibits altruistic stemness phenotype which was previously reported by us in ES cells. Our findings may open up new understanding of the LSC-mediated cancer relapse and drug resistance.

Citation Format: Bidisha Pal, Anupam Sarma, Joyeeta Talukdar, Seema Bhuyan, Sora Sandhya, Sukanya Gayan, Gayatri Gogoi, Debabrat Baishya, Amal Chandra Kataki, Dean W. Felsher, Bikul Das. MYC through HIF-2α regulates the altruistic stemness program in human leukemia stem cells [abstract]. In: Proceedings of the Second AACR Conference on Hematologic Malignancies: Translating Discoveries to Novel Therapies; May 6-9, 2017; Boston, MA. Philadelphia (PA): AACR; Clin Cancer Res 2017;23(24_Suppl):Abstract nr 42.

Abstract 2056: MYC and HIF-2alpha mediates resistance to Epidermal Growth Factor Receptor (EGFR) antagonism in oral squamous carcinoma cells

Background: Oral squamous cell carcinoma (OSCC) is a devastating disease. Recent findings suggest that the EGFR antagonist including erlotinib may induce tumor regression alone or in combination with chemo/radiation. Our preliminary clinical study conducted at KaviKrishna laboratory indicates that many poor patients are taking the highly expensive drug Erlotinib, and or equivalent EGFR antagonists. However, oral cancer lesions are often hypoxic, and the hypoxia-induced cellular mechanisms might contribute to drug resistance. Here, we investigated, whether resistance to EGFR antagonists may involve MYC and HIF-2alpha, two transcription factors upregulated during hypoxia by using established oral cancer cell lines. We have also obtained primary oral cancer cells from patients living in the Kamrup district of Assam, where KaviKrishna laboratory is located. We intend to evaluate the drug sensitivity of these oral cancer cells towards EGFR antagonists.

Method: We used SSC-25 and SCC-9 cell lines, as well patient derived primary oral cancer cells (n=5) for the study. Immunomagnetic sorting was performed to obtain ABCG2+ population. The self-renewal was studied using in vitro clonogenic and in vivo serial transplantation assay in NOD/SCID mice.

Results: First, we identified a rare ABCG2+ expressing, highly tumorigenic cell population in SSC-25, and SCC-9 having cancer stem cell (CSC) like characteristics. Second, we found that the ABCG2+ cells exhibited sensitivity to PD158780 (10 uM; 62% inhibition within 48 hours), and AG1478 (10 uM; 56% inhibition within 48 hours), two small molecular inhibitors of EGFR tyrosine kinase. These small molecular inhibitors significantly inhibited the clonogenic capacity of the ABCG2+ cells. Next, we found that ABCG2+ cells also showed sensitivity to Erlotinib in the in vitro clonogenic assay. Third, the ABCG2+ cells, when exposed to hypoxia (&lt;0.1% O2, 24 hours), exhibited enhanced expression and transcriptional activity of MYC, and HIF-2alpha. The post-hypoxia ABCG2+ cells exhibited complete resistance to PD158780, AG1478 and Erlotinib treatment, which could be reversed by siRNA silencing of MYC and or HIF-2alpha. ChIP assay revealed that HIF-2alpha directly binds to MYC in ABCG2+ cells. We found similar results in ABCG2+ cells obtained from primary oral cancer samples (n=4). Importantly, ABCG2+ cells directly isolated from patients exhibited hypoxic phenotype, including the high expression of HIF-1alpha, and HIF-2alpha, as well as resistance to erlotinib. Furthermore, erlotinib enhanced the stemness of ABCG2+ cells by activation of the MYC/HIF-2alpha self-renewal pathway (1).

Conclusion: These data indicate that MYC and HIF-2alpha co-operate to mediate intrinsic resistance of oral squamous cancer cells to EGFR antagonist in the hypoxia microenvironment.

(1). Bhuyan et al. Cancer Research, volume 76 (14), abstract 935; 2016

Note: This abstract was not presented at the meeting.

Citation Format: Sukanya Gayan, Reza Bayat-Mokhtari, Bidisha Pal, Anupam Sarma, Joyeeta Talkudar, Sorra Sandhya, Rashmi Bhuyan, Seema Bhuyan, Jaishree Garhyan, Debabrat Baishya, Amal Kataki, Rakesh Bhatnagar, Herman Yeger, Bikul Das. MYC and HIF-2alpha mediates resistance to Epidermal Growth Factor Receptor (EGFR) antagonism in oral squamous carcinoma cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2056. doi:10.1158/1538-7445.AM2017-2056

Abstract 2681: Oral micro biome enhances stemness in oral cancer cells by activating Toll like receptor signaling

Background: The resistance and progression of cancers after chemotherapy to invasive and metastatic stages accounts for the overwhelming majority of cancer deaths. Recent studies suggest, microbiomes can induce a cascade of host events to either support or inhibit tumor growth. Specially, in oral cancer, chemotherapy treatment may alter the oral microbial flora, which may favor or inhibit tumor growth. Hence, it is importantl to develop novel experimental approaches to study the role of oral microbial flora in oral cancer stemness (self-renewal and undifferntiated state of cancer stem cells). Importantly, patients in developing area, including Assam, where KaviKrishna laboratory is located, may have distinct oral microbial flora that could favor oral cancer growth. Hence, it is important to include patients from developing countries for such studies. Our previous research showed that chemotherapy ehances stemenss in many cancer cell types, including oral squamous cell carcinoma cell line SSC-25. The stemness switch is characterized by enhanced expression of stemness associated genes including Nanog, Lin28A/B, Oct-4, MYC, HIF-2alpha and inflammation associated genes including Toll like receptor (TLR) 2/4. Here we investigated the role of oral microbiomes in the TLR mediated stemness switch of oral cancer cells.

Methods: SCC-25 oral cancer cell line was treated with bacterial product lipopoly saccharide (LPS), and the stemness switch evaluated by isolation of ABCG2+ cells and expression of stemness associated genes by these cells. Capacity of interaction of tumor stromal cells with mesenchymal stem cells was also evaluated. Additionally, we obtained sputum from oral cancer subjects undergoing chemotherapy. The patients were from the Kamrup district of Assam, where KaviKrishna laboratory is located. The sputum was processed and then added to the culture medium of SCC-25 cells. These post-sputum treated SCC-25 cells were subjected to phenotypic stemness switch analysis.

Results: We found, LPS and sputum treatment led to the enhanced stemness of ABCG2+ cells, including the high expression of TLR2/4, MYC, Nanog, Sox-2, and HIF-2alpha. Importantly, sputum derived from oral cancer subjects under remission showed inhibitory activity on ABCG2+ cell self-renewal. In contrast, sputum obtained from oral cancer subjects with relapse showed enhanced stemness of ABCG2+ cells, and also increased tumorigenic potential. The post-sputum treated ABCG2+ cells exhibited high expression of TLR2/4 and associated increase of HIF-2alpha and MYC transcriptional activity. The sputum treated with broad spectrum antibiotic ciprofloxacin did not enhance the stemness and TLR2/4 signaling of SCC-25 cells.

Conclusion: These results indicate that oral microbiomes may differentially influence the stemness of oral cancer cells. We also conclude that live bacteria present in the sputum may be required to enhance stemness in a TLR2/4 dependent manner.

Note: This abstract was not presented at the meeting.

Citation Format: Joyeeta Talukdar, Rashmi Bhuyan, Bidisha Pal, Sorra Sandhya, Hong Li, Seema Bhuyan, Sukanya Garhyan, Debabrat Baishya, Anupam Sarma, Jyotirmoy Phukan, Amal Kataki, Bikul Das. Oral micro biome enhances stemness in oral cancer cells by activating Toll like receptor signaling [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2681. doi:10.1158/1538-7445.AM2017-2681

Utilization of Euryale ferox Salisbury seed shell for removal of basic fuchsin dye from water: equilibrium and kinetics investigation

Euryale ferox Salisbury (E. ferox) is an environmentally and economically important wetland macrophyte.

Abstract 935: Oral cancer cells may hijack stem cell altruism to survive during extreme hypoxia, and exposure to chemotherapeutic drugs

The mechanism of tumor hypoxia induced reprogramming of cancer cells are not understood well. Hypoxia might activate evolutionary preserved cellular defense mechanism that could contribute to tumor progression and metastasis. We recently described that during hypoxia/oxidative stress, human embryonic stem cells (hES) exhibit an altruistic defense mechanism, where a few cells reprogram to a highly undifferentiated state, and secrete glutathione to protect rest of the community of cells from oxidative stress induced DNA damage (Das B et al, Stem Cells, 2012). The altruistic stem cells phenotype exhibited high HIF-2alpha and low p53 activity. After a few weeks, the reprogrammed cells, although highly fit to survives, underwent spontaneous apoptosis/differentiation by re-activating the p53/MDM2 oscillation. Thus, the reprogrammed cells sacrificed its own fitness to enhance the fitness of the rest of the community, an altruistic behavior (Das B et al. Stem Cells, 2012). Here, we investigated the potential hijacking of the altruistic defense mechanism by oral cancer cells during exposure to hypoxia. We exposed the four oral cancer cell lines SCC-25, SCC-15, SCC-9 and SCC-5 to extreme hypoxia followed by re-oxygenation for 72 hours. We found that while majority of cancer cells underwent apoptosis, a few cancer cell lines survived, exhibited side-population (SP) phenotype, high level of HIF-2alpha, Nanog, Sox-2 and MYC. The SP cells exhibited migratory activity, as well as high tumorigenic and metastatic activity in NOD/SCID mice. ChIP assay indicated that HIF-2alhpa interact with MYC and NOTCH1. The conditioned media of SP cells exhibited high level of glutathione, and ability to protect non-SP cells from cisplatin-induced toxicity. These results indicate that HIF-2alpha and MYC may cooperate to reprogram a few oral cancer cells to altruistic stemness phenotype. The altruistic phenotype that exhibited cytoprotective activity against cisplatin mediated toxicity. Thus, similar to bacteria, where altruistic biofilm exhibit novel drug resistance mechanism, stem cell altruism may serve as a novel drug resistance mechanism in oral cancer.

Citation Format: Rashmi Bhuyan, Hong Li, Sukanya Gayan, Bidisha Pal, Reza Bayat-Mokhtari, Jyotirmoy Phukan, Debabrata Baishya, Anupam Sarma, Joyeeta Talukdar, Manaf Muhammad Alkurdi, Wael Tasabehji, Seema Bhuyan, Gayatri Gogoi, Ista Pulu, Herman Yeger, Bikul Das. Oral cancer cells may hijack stem cell altruism to survive during extreme hypoxia, and exposure to chemotherapeutic drugs. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 935.

Abstract 920: Migratory cancer side population cells induces stem cell altruism in bone marrow mesenchymal stem cells to resist therapy, and enhance tumorigenic potential of non-tumorigenic cells

Stem cell may exhibit altruistic behavior that may benefit cancer cells. We recently demonstrated altruistic phenotype in human embryonic stem cells (Das B et al. Stem Cells 2012). The phenotype exhibited reversible induction of high HIF-2alpha and low p53 expression, associated with high glutathione secretion. We speculated that cancer stem cell might induce a similar altruistic phenotype in human bone marrow (BM) derived stem cells (hematopoietic, mesenchymal and endothelial cells). The altruistic reprogrammed BM cells may then facilitate tumor growth, as well as resist the toxicity of oxidative-stress inducing anti-cancer agents. To investigate this possibility, we have obtained conditioned media (CM) from migratory side-population (SPm) and non-SP cells of a diverse panel of tumors including epithelial tumors. The SPm cells exhibit very high tumorigenic capacity (Das B et al, Stem Cell, 2008). The CM was added to in vitro bone marrow (BM) derived CD133+ cells that contain hematopoietic, endothelial, and mesenchymal stem cells. We found that SPm derived CM (henceforth known as SPm-CM) treatment increased the self-renewal capacity of CD271+/CD45- BM-MSCs. Importantly, the reprogrammed CD271+ BM-MSCs (henceforth known as R-MSCs) phenotype exhibited enhanced stemness reprogramming, a cytoprotective mechanism associated with stem cell altruism (Das B et al. Stem Cells, 2012). In contrast, the treatment with CM obtained from non-SP cells did not exhibit R-MSCs. We found that VEGF/VEGR1 autocrine signaling may be involved in R-MSCs mechanism. Importantly, the R-MSCs derived CM reprogrammed non-CSCs to CSCs, and reduced the toxicity of chemotherapy on non-SP cells. In vivo, R-MSCs derived CM, when injected to mice, exhibited mobilization of CD271+ BM-MSCs to circulation. The circulatory CD271+ BM-MSCs exhibited distinct phenotype of R-MSCs including high expression of HIF-2alpha, and VEGFR1. Finally, in human cancer patients, we identified R-MSC phenotype in the peripheral circulation. These studies suggest that cancer stem cells may exploit stem cell altruism to reprogram BM-MSCs for their own benefit. The reprogrammed BM-MSCs gene expression may have the potential as a diagnostic marker for CSC-induced stem cell altruism.

Citation Format: Joyeeta Talukdar, Rashmi Bhuyan, Jaishree Garhyan, Bidisha Pal, Sora Sandhya, Sukanya Gayan, Anupam Sarma, Reza Bayat-Mokhtari, Hong Li, Jyotirmoy Phukan, Wael Tasabehji, Seema Bhuyan, Amal Ch Kataki, Rika Tsuchida, Herman Yeger, Debabrata Baishya, Bikul Das. Migratory cancer side population cells induces stem cell altruism in bone marrow mesenchymal stem cells to resist therapy, and enhance tumorigenic potential of non-tumorigenic cells. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 920.

Abstract 4073: The potential role of oral mucosa stem cell altruistic behavior as the initiating event of malignant transformation

Oral cancer presents a major health burden across the globe, specially in developing countries. Kamrup, a district of India, where the KaviKrishna laboratory is located has the highest incidence of oral cancer in the entire world. The mechanism of oral cancer carcinogenesis process is not clearly known. Previous studies indicate the potential role of HPV-16 virus as well as tobacco consumption as major contributing factors of oral cancer. In mouse, the carcinogen agent 4-NQO was found to induce oral cancer having similar phenotype as human oral mucosa cancer. 4-NQO may exert tobacco like oxidative stress toxicity to oral mucosa. Hence, developing both in vitro and in vivo models of HPV-16 and 4-NQO mediated oral carcinogenesis might help to understand the initiating event of oral carcinogenesis. In this study, we propose that oral mucosa stem cells (OMSCs) could be the target of HPV-16, and 4-NQO induced carcinogensis. Thus, in vitro treatment of oral mucosa cells of healthy human volunteers with HPV-16 protein E6, and 4-NQO led to expansion of CD271+ cells, which are enriched in OMSCs. Importantly, the expanded CD271+ cells exhibited high HIF-2alpha, low p53, and high glutathione secretion, a phenotype of stem cell altruism that we recently described in human embryonic stem cells (Das B et al. Stem Cells, 2012). In human ES cells, the altruistic reprogramming served as an initiating event of malignant transformation by altering p53/MDM2 oscillation, in an abnormal state of low p53 and high MDM2. Therefore, we performed a complete evaluation of E6 protein and 4-NQO treated CD271+ oral mucosa cells for altruistic behavior, including low p53 and high MDM2 state. For this purpose, the carcinogen treated oral mucosa cells were subjected to immunomagnetic sorting for CD271+ cells. We found that post-carcinogen treated CD271+ cells exhibited in vitro self-renewal activity, high GSH secretion, and importantly activation of a HIF-2alpha/MYC co-operation. ChiP assay revealed the MYC binding to HIF-2alpha, and Sox-2, an stemness associated transcription factor. Importantly, HIF-2alpha was important for the reversible but prolonged suppression of p53 for more than two weeks. We also found that the high HIF-2alpha and low p53 expressing CD271+ cells could be enriched in a ABCG2+ population. Thus, we were able to enrich a CD271+/ABCG2+ cell population in oral mucosa cells of both human and mouse. Based on these findings we propose to use HPV-16 and 4NQO derived carcinogenesis models to study the potential role of altruistic reprogramming in the malignant transformation of oral mucosa stem cells to oral cancer stem cell like cells. Our study may unravel a novel mechanism of malignant transformation, the failure of altruistic stem cells to sacrifice its fitness (altruism) as a potential initiating event of malignant transformation of stem cells to cancer stem cells.

Citation Format: Sukanya Gayan, Hong Li, Rashmi Bhuyan, Sora Sandhya, Joyeeta Talukdar, Bidisha Pal, Jaishree Garhyan, Wael Tasabehji, Manaf Muhammad Alkurdi, Heidar Zohrehei, Seema Bhuyan, Anupam Sarma, Gayatri Gogoi, A.C. Kataki, Rakesh Bhatnagar, Debabrata Baishya, Bikul Das. The potential role of oral mucosa stem cell altruistic behavior as the initiating event of malignant transformation. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 4073.

Abstract 251: Stem cell altruism may serve as a novel drug resistance mechanism in oral cancer

Background: The mechanism of oral squamous cell carcinoma resistance to platinum-based chemotherapy is not clearly known. Previous studies indicated that glutathione (GSH), a cellular antioxidant may detoxify cisplatinum (CDDP), a commonly used chemotherapy agent in oral cancer. Our previous research in human embryonic stem cells (hESCs) indicated the altruistic behavior of ABCG2+ hESCs that secrete high level of GSH to protect other hESCs exposed to oxidative stress (Das B et al. Stem Cells, 2012). Here we investigated if CDDP exposure lead to altruistic stem cell reprogramming of ABCG2+ oral squamous cell carcinoma cells and subsequent GSH-mediated resistance against CDDP. Methods: Two oral squamous cell cancer cell lines SCC-25 and SCC-15 were treated with 3-10 uM CDDP for three-days, and then subjected to flow cytometry and immunomagnetic sorting based evaluation of ABCG2+ cells. The conditioned media (CM) obtained from ABCG2+ cells were examined for GSH content. The CM treated cancer cell lines were examined for resistance against CDDP toxicity. Next, the post-CDDP treated ABCG2+ cells were examined for enhanced stemness phenotype that corresponds to altruistic stem cell phenotype (Das B et al, Stem Cells 2012). Results: We found that CDDP treatment increases the ABCG2+ self-renewal capacity of SCC-25 and SCC-15 cells as measured by serial transplantation assay. The CM of the post-CDDP treated cells exhibited high level of GSH. When the SCC-15 and SCC-25 cells were treated with CM plus CDDP, the cancer cells exhibited 10-15-fold increase in resistance against CDDP toxicity. Next, the post-CDDP treated SCC-25 and SCC-15 cells exhibited enhanced stemness reprogramming phenotype characterized by very high HIF-2alpha, Sox-2 and Nanog transcriptional activity. Furthemore, we found increased expression of EMT (epithelial mesenchymal transition) marker expression including Snail, Twist and vimentin as evaluated by flow cytometry. siRNA HIF-2alpha treatment led to marked loss in the in vivo self-renewal capacity of ABCG2+ SCC-25 and SCC-15 cells. We then noted that post-CDDP ABCG2+ cells exhibited reversible state, as after two weeks of culture, most of the cells either differentiated or underwent apoptosis. Conclusions: These results indicate that oral cancer cells exhibit altruistic defense mechanism to resist the toxicity of CDDP. The altruistic defense mechanism involved high secretion of GSH. Thus, we suggest that similar to bacterial altruism as a mechanism of drug resistance, stem cell altruism may also serve as a novel mechanism of drug resistance in cancer.

Citation Format: Bidisha Pal, Reza Bayat-Mokhtari, Hong Li, Rashmi Bhuyan, Joyeeta Talukdar, Sora Sandhya, Anupam Sarma, Wael Tasabehji, Seema Bhuyan, Sukanya Gayan, Amal Ch Kataki, Debabrata Baishya, Herman Yeger, Dean W. Felsher, Bikul Das. Stem cell altruism may serve as a novel drug resistance mechanism in oral cancer. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 251.

Expression of aberrant CD markers in acute leukemia: a study of 100 cases with immunophenotyping by multiparameter flowcytometry

BACKGROUND

Acute leukemia is a heterogenous disease having diverse phenotypes. Immunophenotyping by flowcytometry is essential for diagnosis of myeloid and lymphoid subtypes. Aberrant phenotype incidence is controversial and dissimilar results have been reported by different groups.

OBJECTIVES

Purpose of the study was to determine the incidence of aberrant phenotypes in North East Indian patients with acute leukemia.

METHODS

We analysed a total of 100 cases (AML = 36, ALL = 61, MPAL = 3) by multiparametric flow cytometry using an acute panel of monoclonal antibodies (MoAbs). The MoAbs were selected to identify differentiation-associated antigens of both myeloid and lymphoid lineages.

RESULTS

Aberrant phenotypes were found in 21 (58.3%) cases of AML, 36 (59.2%) cases of B-ALL and 6 (66.7%) cases of T-ALL. CD7 was the most frequent lymphoid associated antigen found in 33% of AML cases while CD117 was the myeloid antigen most frequently detected in ALL (54%) cases. Aberrant expression of CD 117 is highly significant by Fischer's exact test (P< 0.0001).

CONCLUSION

We conclude that aberrant phenotypes are present in a great majority of acute leukemia patients of North East India. Future studies will be directed to correlate of these markers with prognosis and therapeutic response.