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Anjali Seth

Publications and source records attributed to Anjali Seth.

4 recordsLinked to original sources

Lung Squamous Cell Carcinoma Harbouring a Novel PAX8::PPARγ Fusion and a FGFR2 Exon 7 Missense Mutation.

Comprehensive molecular profiling is now routinely performed in newly diagnosed non-small cell lung carcinomas (NSCLCs) to identify actionable genomic alterations. Although numerous molecular abnormalities have been described in lung carcinomas, rare and unexpected gene fusions may create significant diagnostic challenges, particularly when they are characteristically associated with tumours of different lineages. To our knowledge, this is the first reported case of a primary lung squamous cell carcinoma harbouring an in-frame PAX8::PPARγ fusion with a concurrent FGFR2 exon 7 missense mutation (p.W290C). An 80-year-old man with a smoking history exceeding 50 years presented with a rapidly enlarging PET-avid right upper lobe pulmonary mass. Bronchial brushing cytology demonstrated a hypercellular malignant neoplasm composed of pleomorphic squamoid cells with hyperchromatic nuclei, dense cytoplasm and extensive necrosis. Cell block material showed squamous morphology and diffuse p40 positivity, supporting squamous differentiation. Reflex next-generation sequencing identified an FGFR2 exon 7 missense mutation (p.W290C; c.870G>C) and targeted RNA fusion analysis demonstrated an in-frame PAX8::PPARγ fusion resulting from a t(2;3)(q13;p25.2) translocation. Because PAX8::PPARγ rearrangements are strongly associated with follicular thyroid neoplasms, extensive clinicoradiologic and immunohistochemical correlation was performed to exclude metastatic thyroid carcinoma. Imaging studies showed no thyroid lesion or residual thyroid tissue, and tumour cells were negative for thyroglobulin, TTF-1 and PAX8. Correlation of the clinical history, radiologic findings, cytomorphology, immunophenotype and molecular profile supported the diagnosis of primary lung squamous cell carcinoma. This case expands the molecular spectrum of lung squamous cell carcinoma and highlights the importance of integrated cytopathologic, immunohistochemical, molecular and radiologic evaluation when unexpected gene fusions are identified in cytology specimens.

FGFR2 exon 7 missense mutation↗

High-throughput single-cell proteomics and transcriptomics from same cells with a nanoliter-scale, spin-transfer approach.

Single-cell multiomic platforms provide a comprehensive snapshot of cellular states and cell types by offering critical insights into the spatiotemporal regulation of biomolecular networks at a systems level, thereby defining the basis of multicellularity. Here, we introduce nanoSPINS, an advanced platform that enables high-throughput profiling and integrative analysis of the transcriptome and proteome from the same single cells using RNA sequencing and isobaric labeling LC-MS-based proteomics, respectively. NanoSPINS can efficiently transfer mRNA-containing droplets across two microarrays via a centrifugation-based approach, while proteins are retained on the initial platform. Benchmarking of nanoSPINS on two cell lines demonstrates its ability to generate global proteomic and transcriptomic profiles that align well with previously established methodologies/platforms. The incorporation of isobaric TMTpro labeling into this single-cell multiomics platform significantly enhances the throughput of single-cell proteomic analyses. Through the high-throughput quantification of the proteome and transcriptome, nanoSPINS not only facilitates the identification of molecular features at both mRNA and protein level but also provides larger sample sizes for improved statistical power in clustering and differential abundance. Given the broad applicability of single-cell multiomics in biological research and clinical settings, we believe nanoSPINS represents a powerful platform for the characterization of heterogeneous cell populations.

Single-Cell Analysis↗

Arginine homeostasis in J774.1 macrophages in the context of Mycobacterium bovis BCG infection.

The competition for L-arginine between the inducible nitric oxide synthase and arginase contributes to the outcome of several parasitic and bacterial infections. The acquisition of L-arginine, however, is important not only for the host cells but also for the intracellular pathogen. In this study we observe that strain AS-1, the Mycobacterium bovis BCG strain lacking the Rv0522 gene, which encodes an arginine permease, perturbs l-arginine metabolism in J774.1 murine macrophages. Infection with AS-1, but not with wild-type BCG, induced l-arginine uptake in J774.1 cells. This increase in L-arginine uptake was independent of activation with gamma interferon plus lipopolysaccharide and correlated with increased expression of the MCAT1 and MCAT2 cationic amino acid transport genes. AS-1 infection also enhanced arginase activity in resting J774.1 cells. Survival studies revealed that AS-1 survived better than BCG within resting J774.1 cells. Intracellular growth of AS-1 was further enhanced by inhibiting arginase and ornithine decarboxylase activities in J774.1 cells using L-norvaline and difluoromethylornithine treatment, respectively. These results suggest that the arginine-related activities of J774.1 macrophages are affected by the arginine transport capacity of the infecting BCG strain. The loss of Rv0522 gene-encoded arginine transport may have induced other cationic amino acid transport systems during intracellular growth of AS-1, allowing better survival within resting macrophages.

Amino Acid Transport Systems, Basic↗

Modulation of J774.1 macrophage L-arginine metabolism by intracellular Mycobacterium bovis BCG.

Using a Mycobacterium bovis BCG mutant (AS1) lacking a Bacillus subtilis L-arginine transporter homolog, we demonstrate here that the interaction between intracellular mycobacteria and the macrophage with respect to L-arginine transport and metabolism is quite complex. Intracellular AS1 stimulates macrophage L-arginine transport and accumulates 2.5-fold more (3)H label derived from L-arginine than does the wild type. These studies suggest that the accumulation of (3)H label reflects the acquisition of metabolites of L-arginine produced by the macrophage.

Amino Acid Transport Systems↗