Biology subjects

Kulshreshtha, A.

Publications and source records attributed to Kulshreshtha, A..

4 recordsLinked to original sources

bioRxiv2025

HPV integration in head and neck cancer: downstream splicing events and expression ratios linked with poor outcomes

HPV integration (HPVint) is associated with carcinogenesis and tumor progression in HPV-associated cancers, including head and neck squamous cell carcinomas (HNSCC). While its impact on human DNA has been well characterized, its relationship with clinical outcomes remains unconfirmed. Here we investigate the consequences of HPVint both with respect to human and HPV characteristics by analyzing 261 HPV-associated HNSCC bulk and single-cell RNA-seq samples from five cohorts, and DNA HPVint events from 102 HPV+ participants in two of the cohorts. By leveraging this large meta-cohort, we first reveal an oncogenic network based on the recurrent HPV integration locations in HNSCC. We then classify HPVint-positive (HPVint(+)) participants by HPV RNA features, specifically based on spliced HPV-human fusion transcripts and ratios of HPV gene transcripts, showing that subsets of participants have worse clinical outcomes. Our analyses, focused mainly on RNA instead of DNA, expand our understanding of the carcinogenic mechanisms of HPVint, partially addressing the conflicting findings of whether HPVint is associated with aggressive phenotypes and worse clinical consequences, and provide potential biomarkers to advance precision oncology in HPV-associated HNSCC.

cancer biology↗

bioRxiv2024

APV9WR: An Integrated Web Resource of Alpha papillomavirus 9 for Genomics, Proteomics, Phylogenetic and Therapeutic Analysis

PurposeAlphapapillomavirus 9 is a virus belonging to the Papillomaviridae family. It has a close genetic relationship with high-risk HPV-16 and other HPV strains such as HPV-31, HPV-52, HPV-35, HPV-58, HPV-67, and HPV-35. This virus is responsible for causing warts and malignant tumors and is responsible for about 75% of cervical malignancies and pre-cancerous lesions worldwide. As a result, it requires specialized research and attention. Our goal is to create a comprehensive resource that can assist researchers and scientific groups in their work. Material and MethodologyA total of 1230 full genome sequences and 9140 protein sequences were obtained from GenBank and NCBI Virus, respectively. Further Phylogenetic Analysis, Codon usage and context analysis, CpG islands analysis, Glycosylation sites, Diagnostic Primers, B cell Epitopes and MHC I and MHC II binders were identified and analyzed using relevant Bioinformatics tools and Python program ResultsAPV9WR is a web resource that was developed after analysis. Our data indicate that HPV 35 and HPV 38 have the most genomic diversity. From codon usage analysis, it was observed that AAA, AUU, UAU, UGU, and UUU are the most used codons, while ACG, CCG, CGA, CGG, CGU, GCG, and UCG are some of the unusual codons in APV9 nucleotide sequence with accession id - LC626346.1. We found 4714 CpG island locations in 1230 complete nucleotide sequences of APV9, and only 663 CpG island locations were unique. Further N-linked glycosylation, O-linked glycosylation, diagnostic primers, Potential B-cell epitopes and MHC I and MHC II binders were also analyzed and tabulated. ConclusionWe have consolidated basic information about the virus, such as entire genomic sequences and proteins. It primarily comprises a wide range of studies and outcomes, including genome alignment, phylogenetic inferences, codon context and usage bias, and important CpG island statistics. Furthermore, primers for molecular diagnostics were identified, and glycosylation sites were located and investigated. Most significantly, potential therapeutic elements such as vaccine epitopes and obtaining potential information about them were investigated. Our collective effort on this tool is meant to serve the greater good of the research community for therapeutic intervention for Alphapapillomavirus 9. Using this link https://apv9nsut.web.app will take you to the web app.

bioinformatics↗

bioRxiv2023

Inhibiting the GPI Transamidase Subunit GPAA1 Abolishes CD24 Surface Localization and Enhances Macrophage-Mediated Phagocytosis of Ovarian Cancer Cells

The CD24-Siglec10 signaling axis is an immune checkpoint pathway that shields ovarian cancer cells from phagocytosis by tumor-associated macrophages (TAMs), making it an appealing immunotherapeutic target. Here, we investigate factors influencing CD24 cell surface expression and assess their suitability as drug targets. Using a CRISPR-based knockout screen, we identify GPAA1 (glycosylphosphatidylinositol anchor attachment-1) as a positive regulator of CD24 cell surface expression. GPAA1 is a crucial component of the multi-subunit GPI transamidase complex, which facilitates the attachment of GPI lipid anchor to the C-terminus of CD24, enabling its surface localization. Reducing the activity of GPAA1 in ovarian cancer cells, either by genetic ablation or targeting with an aminopeptidase inhibitor bestatin, disrupts GPI attachment to CD24. This disruption impairs CD24 cell surface localization, enhances phagocytosis by TAMs, and suppresses tumor growth in mice. Our study highlights the potential of GPAA1 targeting as a therapeutic approach for CD24-positive ovarian cancers.

cancer biology↗

bioRxiv2018

Simvastatin mediates inhibition of exosome synthesis, localization, and secretion via multicomponent interventions.

Discovery of exosomes as modulator of cellular communication has added a new dimension to our understanding of biological processes. Exosomes influence the biological systems by mediating trans-communication across tissues and cells, which has important implication for health and disease. Identification of strategies for exosome modulation may pave the way towards better understanding of exosome biology and development of novel therapeutics. In absence of well-characterized modulators of exosome biogenesis, an alternative option is to target pathways generating important exosomal components. Cholesterol represents one such essential component required for exosomal biogenesis. We initiated this study to test the hypothesis that owing to its cholesterol lowering effect, simvastatin, a HMG CoA inhibitor, might be able to alter exosome formation and secretion. Using previously established protocols for detecting secreted exosomes in biological fluids, simvastatin was tested for its effect on exosome secretion under various in-vitro and in-vivo settings. Murine model of AAI was used for further validation of our findings. Utilizing aforementioned systems, we demonstrate exosome-lowering potential of simvastatin in various in-vivo and in-vitro models, of AAI and atherosclerosis. We believe that the knowledge acquired in this study holds potential for extension to other exosome dominated pathologies and model systems.

cell biology↗