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result(s) for
"Basu Anamika"
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Theoretical study of the antioxidant mechanism of chrysin and its metabolites – a computational approach
2026
Flavonoid chrysin, obtained from different plants, has different pharmacological property, due to its antioxidative effects. But the poor bioavailability of chrysin limits its therapeutics application. In systemic circulation, chrysin can be transported by binding with serum albumin protein. Furthermore, in hepatic circulation, two chrysin metabolites e.g. chrysin-7-O-glucuronide (C7G) and chrysin-7-O-sulphate (C7S) are formed by biotransformation process in liver. By using computational methods like density functional theory (DFT) study, the antioxidant potential of these four compounds has been investigated. In this study, both the Highest Occupied Molecular Orbital (HOMO) and the Lowest Unoccupied Molecular Orbital (LUMO) have been identified by using Gaussian software. The energies of these orbitals, as well as the energy gap between HOMO and LUMO, have been calculated. Using these calculations, it can be concluded that chrysin in its bound form with human serum albumin, is the best antioxidant among these four compounds. Since, it has the lowest energy gap between the calculated HOMO and LUMO. In this bound form, the cinnamoyl group present in chrysin molecule participates in the charge transfer event. The antioxidant activity by donating electrons to scavenge the free radicles, has been explained for chrysin and its derivatives. Global descriptive parameters, which describe the reactivity and stability of molecules, are calculated to highlight the electron or proton donation/acceptance of these four compounds. Antioxidant efficiency correlates strongly with electron-donating ability and stability of the resulting radical. The albumin bound chrysin is considered as best antioxidant among these four compounds for the three types of antioxidation reaction mechanisms. This finding will help us to overcome the problem regarding poor bioavailability of chrysin during its performance as antioxidant.
Journal Article
In Silico Epitope-Based Vaccine Prediction against Fungal Infection Aspergillosis
2022
Aspergillus fumigatus is a pathogenic microorganism that causes aspergillosis due to the presence of its allergenic proteins. During the last two years, a few clinical cases have been reported where allergic bronchopulmonary aspergillosis (ABPA) has been detected in COVID-19 patients. The administration of antifungal medicine did not provide satisfactory results. It is a challenging job for medical scientists to protect mankind by designing an epitope-based vaccine against the rare disease aspergillosis. Other than twenty-three allergenic proteins, this microorganism contains an extra-cellular cellulase CelA expansin protein (Afu5g08030), which is allergenic. To design a peptide vaccine against aspergillosis, the identification of B cell and T cell epitopes is state-of-the-art technology. In our latest research, probable T cell and B cell epitopes are predicted. Molecular docking analysis of these predicted epitopes with their receptors is performed. Here, the primary sequence of the expansin protein is extracted and analyzed. Then, its secondary and tertiary structures are predicted using a homology modeling method and validated. Considering the physicochemical properties of this antigenic protein, two short stretches of peptides, namely 80KPQADEDPNASSSSSSS96 and 286DGGKTWQGTTRTS298, are predicted as linear B cell epitopes. Similarly, based on its contacts with the highest number of alleles, the peptide sequence 221LDLFQNAFTQLADVS235 is chosen as the most possible T cell epitope for the protein present in Aspergillus fumigatus with the highest binding energy for MHC II allele HLA-DRB1* 01: 01. Considering the binding energy of the B cell epitope with IgE, the second epitope 286DGGKTWQGTTRTS298 is designated as the most potential epitope of B cells for this protein. Docking studies were performed with the T cell epitope with the human ternary complex of T cell receptor, CD4 receptor, and peptide-MHC II molecule (PDB ID 3T0E) with a binding energy of −192 Kcal/mole. For peptide-based vaccines, the proposed B cell and T cell epitopes may be used against aspergillosis after further experimental analysis.
Journal Article
Immunoinformatics Based Study of T Cell Epitopes in Zea m 1 Pollen Allergen
2019
Background and Objectives: Zea m 1 is a pollen allergen, which is present in maize, is accountable for a type I hypersensitivity reaction in all over the world. Several effective medications are available for the disorder with various side effects. Design and verification of a peptide-based vaccine is a state-of-art technology which is more cost effective than conventional drugs. Materials and Methods: Using immunoinformatic methods, the T cell epitopes from the whole structure of this allergenic protein can be predicted. Worldwide conserved region study among the other pollen allergens has been performed for T cell predicted epitopes by using a conservancy tool. This analysis will help to identify completely conserved HLA (human leukocyte antigen) binding epitopes. Lastly, molecular docking study and MHC-oligopeptide complex binding energy calculation data are applied to determine the interacting amino acids and the affinity of the epitopes to the class II MHCmolecule. Results: The study of criteria-based analysis predicts the presence of two epitopes YVADDGDIV and WRMDTAKAL on this pollen allergen. Conclusions: The T cell epitopes identified in this study provide insight into a peptide-based vaccine for a type I hypersensitivity reaction induced by Zea m 1 grass pollen allergenic protein.
Journal Article
The association of genomic lesions and PD-1/PD-L1 expression in resected triple-negative breast cancers
by
McCullough, Ann E.
,
Kosiorek, Heidi E.
,
Yearley, Jennifer Holmes
in
Adaptive immunity
,
Analysis
,
Biological markers
2018
Background
Elevated PD-L1 expression on tumor cells, a context associated with an adaptive immune response, has been linked to the total burden of copy number variants (CNVs) in aneuploid tumors, to microsatellite instability (MSI), and to specific genomic driver lesions, including loss of
PTEN
,
MYC
amplification, and activating mutations in driver oncogenes such as
KRAS
and
PIK3CA
. Triple-negative breast cancers (TNBCs) typically have high levels of CNVs and diverse driver lesions in their genomes. Thus, there is significant interest in exploiting genomic data to develop predictive immunotherapy biomarkers for patients with TNBC.
Methods
Whole tissue samples from 55 resected TNBCs were screened by immunohistochemistry (IHC) for PD-1 and PD-L1 by using validated antibodies and established scoring methods for staining of tumor and non-tumor cells. In parallel, we interrogated biopsies from each resection with DNA content flow cytometry and sorted the nuclei of diploid, tetraploid, and aneuploid cell populations. CNVs were mapped with CNV oligonucleotide arrays by using purified (>95%) tumor populations. We generated whole exome data for 12 sorted tumor samples to increase the resolution within loci of interest and to incorporate somatic mutations into our genomic signatures.
Results and Conclusions
PD-L1 staining was detected on tumor cells in 29 out of 54 (54%) evaluable cases and was associated with increased overall survival (
P
= 0.0024). High levels of PD-1 and PD-L1 (IHC ≥4) were present in 11 out of 54 (20%) and 20 out of 54 (37%) cases with staining of PD-L1 primarily on tumor cells for 17 out of 20 (85%) cases. The latter included tumors with both high (>50) and low (<20) numbers of CNVs. Notably, homozygous deletion of
PTEN
(
n
= 6) or activating mutation in
PIK3CA
(
n
= 1) was not associated with increased expression of either immune checkpoint activator in TNBC. In contrast, two treatment-naïve cases with
EGFR
driver amplicons had high PD-L1 tumor staining. High mutational load and predicted neoepitopes were observed in MSI
+
and high CNV burden TNBCs but were not associated with high PD-L1 expression on tumor cells. Our results challenge current models of genomic-based immunotherapy signatures yet suggest that discrete genomic lesions may complement existing biomarkers to advance immune checkpoint therapies for patients with TNBC.
Journal Article
Molecular docking study of potential phytochemicals and their effects on the complex of SARS-CoV2 spike protein and human ACE2
by
Basu, Anamika
,
Sarkar, Anasua
,
Maulik, Ujjwal
in
631/114/2248
,
631/154/309/606
,
Allosteric Regulation
2020
Angiotensin converting enzyme 2 (ACE2) (EC:3.4.17.23) is a transmembrane protein which is considered as a receptor for spike protein binding of novel coronavirus (SARS-CoV2). Since no specific medication is available to treat COVID-19, designing of new drug is important and essential. In this regard, in silico method plays an important role, as it is rapid and cost effective compared to the trial and error methods using experimental studies. Natural products are safe and easily available to treat coronavirus affected patients, in the present alarming situation. In this paper five phytochemicals, which belong to flavonoid and anthraquinone subclass, have been selected as small molecules in molecular docking study of spike protein of SARS-CoV2 with its human receptor ACE2 molecule. Their molecular binding sites on spike protein bound structure with its receptor have been analyzed. From this analysis, hesperidin, emodin and chrysin are selected as competent natural products from both Indian and Chinese medicinal plants, to treat COVID-19. Among them, the phytochemical hesperidin can bind with ACE2 protein and bound structure of ACE2 protein and spike protein of SARS-CoV2 noncompetitively. The binding sites of ACE2 protein for spike protein and hesperidin, are located in different parts of ACE2 protein. Ligand spike protein causes conformational change in three-dimensional structure of protein ACE2, which is confirmed by molecular docking and molecular dynamics studies. This compound modulates the binding energy of bound structure of ACE2 and spike protein. This result indicates that due to presence of hesperidin, the bound structure of ACE2 and spike protein fragment becomes unstable. As a result, this natural product can impart antiviral activity in SARS CoV2 infection. The antiviral activity of these five natural compounds are further experimentally validated with QSAR study.
Journal Article
Immunogenomic profiling and pathological response results from a clinical trial of docetaxel and carboplatin in triple-negative breast cancer
by
Peterson, Lindsay L
,
Hagemann, Ian S
,
Skidmore, Zachary L
in
Breast cancer
,
Cancer research
,
Carboplatin
2021
PurposePatients with triple-negative breast cancer (TNBC) who do not achieve pathological complete response (pCR) following neoadjuvant chemotherapy have a high risk of recurrence and death. Molecular characterization may identify patients unlikely to achieve pCR. This neoadjuvant trial was conducted to determine the pCR rate with docetaxel and carboplatin and to identify molecular alterations and/or immune gene signatures predicting pCR.Experimental designPatients with clinical stages II/III TNBC received 6 cycles of docetaxel and carboplatin. The primary objective was to determine if neoadjuvant docetaxel and carboplatin would increase the pCR rate in TNBC compared to historical expectations. We performed whole-exome sequencing (WES) and immune profiling on pre-treatment tumor samples to identify alterations that may predict pCR. Thirteen matching on-treatment samples were also analyzed to assess changes in molecular profiles.ResultsFifty-eight of 127 (45.7%) patients achieved pCR. There was a non-significant trend toward higher mutation burden for patients with residual cancer burden (RCB) 0/I versus RCB II/III (median 80 versus 68 variants, p 0.88). TP53 was the most frequently mutated gene, observed in 85.7% of tumors. EGFR, RB1, RAD51AP2, SDK2, L1CAM, KPRP, PCDHA1, CACNA1S, CFAP58, COL22A1, and COL4A5 mutations were observed almost exclusively in pre-treatment samples from patients who achieved pCR. Seven mutations in PCDHA1 were observed in pre-treatment samples from patients who did not achieve pCR. Several immune gene signatures including IDO1, PD-L1, interferon gamma signaling, CTLA4, cytotoxicity, tumor inflammation signature, inflammatory chemokines, cytotoxic cells, lymphoid, PD-L2, exhausted CD8, Tregs, and immunoproteasome were upregulated in pre-treatment samples from patients who achieved pCR.ConclusionNeoadjuvant docetaxel and carboplatin resulted in a pCR of 45.7%. WES and immune profiling differentiated patients with and without pCR.Trial registration: Clinical trial information: NCT02124902, Registered 24 April 2014 & NCT02547987, Registered 10 September 2015.
Journal Article
Interventions to improve latent and active tuberculosis treatment completion rates in underserved groups in low incidence countries: a scoping review
2024
BackgroundPeople in underserved groups have higher rates of tuberculosis (TB) and poorer treatment outcomes compared with people with no social risk factors.ObjectivesThis scoping review aimed to identify interventions that improve TB treatment adherence or completion rates.Eligibility criteriaStudies of any design focusing on interventions to improve adherence or completion of TB treatment in underserved populations in low incidence countries.Sources of evidenceMEDLINE, Embase and Cochrane CENTRAL were searched (January 2015 to December 2023).Charting methodsPiloted data extraction forms were used. Findings were tabulated and reported narratively. Formal risk of bias assessment or synthesis was not undertaken.Results47 studies were identified. There was substantial heterogeneity in study design, population, intervention components, usual care and definition of completion rates. Most studies were in migrants or refugees, with fewer in populations with other risk factors (eg, homelessness, imprisonment or substance abuse). Based on controlled studies, there was limited evidence to suggest that shorter treatment regimens, video-observed therapy (compared with directly observed therapy), directly observed therapy (compared with self-administered treatment) and approaches that include tailored health or social support beyond TB treatment may lead to improved outcomes. This evidence is mostly observational and subject to confounding. There were no studies in Gypsy, Roma and Traveller populations, or individuals with mental health disorders and only one in sex workers. Barriers to treatment adherence included a lack of knowledge around TB, lack of general health or social support and side effects. Facilitators included health education, trusted relationships between patients and healthcare staff, social support and reduced treatment duration.ConclusionsThe evidence base is limited, and few controlled studies exist. Further high-quality research in well-defined underserved populations is needed to confirm the limited findings and inform policy and practice in TB management. Further qualitative research should include more people from underserved groups.
Journal Article
Personalized ctDNA micro-panels can monitor and predict clinical outcomes for patients with triple-negative breast cancer
by
Fulton, Robert
,
Griffith, Obi L.
,
Richters, Megan M.
in
631/67/1347
,
631/67/1857
,
Biomarkers, Tumor - genetics
2022
Circulating tumor DNA (ctDNA) in peripheral blood has been used to predict prognosis and therapeutic response for triple-negative breast cancer (TNBC) patients. However, previous approaches typically use large comprehensive panels of genes commonly mutated across all breast cancers. Given the reduction in sequencing costs and decreased turnaround times associated with panel generation, the objective of this study was to assess the use of custom micro-panels for tracking disease and predicting clinical outcomes for patients with TNBC. Paired tumor-normal samples from patients with TNBC were obtained at diagnosis (T0) and whole exome sequencing (WES) was performed to identify somatic variants associated with individual tumors. Custom micro-panels of 4–6 variants were created for each individual enrolled in the study. Peripheral blood was obtained at baseline, during Cycle 1 Day 3, at time of surgery, and in 3–6 month intervals after surgery to assess variant allele fraction (VAF) at different timepoints during disease course. The VAF was compared to clinical outcomes to evaluate the ability of custom micro-panels to predict pathological response, disease-free intervals, and patient relapse. A cohort of 50 individuals were evaluated for up to 48 months post-diagnosis of TNBC. In total, there were 33 patients who did not achieve pathological complete response (pCR) and seven patients developed clinical relapse. For all patients who developed clinical relapse and had peripheral blood obtained ≤ 6 months prior to relapse (
n
= 4), the custom ctDNA micro-panels identified molecular relapse at an average of 4.3 months prior to clinical relapse. The custom ctDNA panel results were moderately associated with pCR such that during disease monitoring, only 11% of patients with pCR had a molecular relapse, whereas 47% of patients without pCR had a molecular relapse (Chi-Square;
p
-value = 0.10). In this study, we show that a custom micro-panel of 4–6 markers can be effectively used to predict outcomes and monitor remission for patients with TNBC. These custom micro-panels show high sensitivity for detecting molecular relapse in advance of clinical relapse. The use of these panels could improve patient outcomes through early detection of relapse with preemptive intervention prior to symptom onset.
Journal Article
LEDGF/p75 Overexpression Attenuates Oxidative Stress-Induced Necrosis and Upregulates the Oxidoreductase ERP57/PDIA3/GRP58 in Prostate Cancer
by
Basu, Anamika
,
Leoh, Lai Sum
,
Acevedo-Martinez, Stephanny
in
Acquired immune deficiency syndrome
,
AIDS
,
Apoptosis
2016
Prostate cancer (PCa) mortality is driven by highly aggressive tumors characterized by metastasis and resistance to therapy, and this aggressiveness is mediated by numerous factors, including activation of stress survival pathways in the pro-inflammatory tumor microenvironment. LEDGF/p75, also known as the DFS70 autoantigen, is a stress transcription co-activator implicated in cancer, HIV-AIDS, and autoimmunity. This protein is targeted by autoantibodies in certain subsets of patients with PCa and inflammatory conditions, as well as in some apparently healthy individuals. LEDGF/p75 is overexpressed in PCa and other cancers, and promotes resistance to chemotherapy-induced cell death via the transactivation of survival proteins. We report in this study that overexpression of LEDGF/p75 in PCa cells attenuates oxidative stress-induced necrosis but not staurosporine-induced apoptosis. This finding was consistent with the observation that while LEDGF/p75 was robustly cleaved in apoptotic cells into a p65 fragment that lacks stress survival activity, it remained relatively intact in necrotic cells. Overexpression of LEDGF/p75 in PCa cells led to the upregulation of transcript and protein levels of the thiol-oxidoreductase ERp57 (also known as GRP58 and PDIA3), whereas its depletion led to ERp57 transcript downregulation. Chromatin immunoprecipitation and transcription reporter assays showed LEDGF/p75 binding to and transactivating the ERp57 promoter, respectively. Immunohistochemical analysis revealed significantly elevated co-expression of these two proteins in clinical prostate tumor tissues. Our results suggest that LEDGF/p75 is not an inhibitor of apoptosis but rather an antagonist of oxidative stress-induced necrosis, and that its overexpression in PCa leads to ERp57 upregulation. These findings are of significance in clarifying the role of the LEDGF/p75 stress survival pathway in PCa.
Journal Article