10 results on '"Tomar VS"'
Search Results
2. Targeting genomic receptors in voided urine for confirmation of benign prostatic hyperplasia.
- Author
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Thakur M, Tomar VS, Dale E, Gomella LG, Solomides C, Kolesnikov O, Keith SW, Navarro HT, Dahlgren O, Chaga M, and Trabulsi EJ
- Abstract
Objectives: The objective of this study is to validate a hypothesis that a non-invasive optical imaging assay targeting genomic VPAC receptors on malignant cells shed in voided urine will represent either benign prostatic hyperplasia (BPH) or prostatic cancer (PCa). Risk for BPH in men 50-70 years old is 50-70% and PCa is 17%. BPH and PCa can coexist in 20% of men with BPH. Most commonly practiced methods to diagnose BPH do not distinguish BPH from PCa., Patients or Materials and Methods: Males with BPH ( N = 97, 60.8 ± 6.3 years, prostate-specific antigen 0.7 ± 0.4 ng/mL) and without oncologic disease ( N = 35, 63.4 ± 5.8 years, prostate-specific antigen < 1.5 ng/mL) signed informed consent form and provided voided urine. Urine was cytocentrifuged, cells collected on glass slide, fixed, treated with VPAC specific fluorophore TP4303 (Kd 3.1 × 10
-8 M), washed, incubated with DAPI and observed using a fluorescence microscope. Cells with no VPAC did not fluoresce (BPH) and those with VPAC had red-orange fluorescence (PCa). Real-time polymerase chain reaction analyses for VPAC and NKX3.1 assay for cell origin were performed., Results: Eighty-seven subjects were negative for VPAC expression. Positive VPAC expression was noted in 10 subjects. Patient chart review for clinical data on these 10 VPAC positive subjects showed five had nephrolithiasis, three had renal cysts, one had prostatitis and one was being treated with finasteride. Real-time polymerase chain reaction analysis-VPAC expressions for 7 normal and 12 BPH subjects were 1.31 ± 1.26 and 0.94 ± 0.89, respectively ( P = 0.46). NKX3.1 showed cells of prostate origin for finasteride-treated patient. Specificity for VPAC urine assay for excluding prostate cancer in this BPH cohort was 88.5%, positive predictive value 0.00% and negative predictive value 100%., Conclusion: VPAC assay may contribute extensively for BPH diagnosis and warrant continued investigation., Competing Interests: Drs. Mathew Thakur and Leonard Gomella hold patents on the use of TP4303 Biomolecule stated in this manuscript. Other authors declare that they have no known competing financial interests. None have personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Authors. BJUI Compass published by John Wiley & Sons Ltd on behalf of BJU International Company.)- Published
- 2024
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3. Protection of Regulatory T Cells from Fragility and Inactivation in the Tumor Microenvironment.
- Author
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Zhang H, Tomar VS, Li J, Basavaraja R, Yan F, Gui J, McBrearty N, Costich TL, Beiting DP, Blanco MA, Conejo-Garcia JR, Saggu G, Berger A, Nefedova Y, Gabrilovich DI, and Fuchs SY
- Subjects
- Humans, Tumor Microenvironment, Neuropilin-1, Immunotherapy, T-Lymphocytes, Regulatory, Neoplasms
- Abstract
Fragility of regulatory T (Treg) cells manifested by the loss of neuropilin-1 (NRP1) and expression of IFNγ undermines the immune suppressive functions of Treg cells and contributes to the success of immune therapies against cancers. Intratumoral Treg cells somehow avoid fragility; however, the mechanisms by which Treg cells are protected from fragility in the tumor microenvironment are not well understood. Here, we demonstrate that the IFNAR1 chain of the type I IFN (IFN1) receptor was downregulated on intratumoral Treg cells. Downregulation of IFNAR1 mediated by p38α kinase protected Treg cells from fragility and maintained NRP1 levels, which were decreased in response to IFN1. Genetic or pharmacologic inactivation of p38α and stabilization of IFNAR1 in Treg cells induced fragility and inhibited their immune suppressive and protumorigenic activities. The inhibitor of sumoylation TAK981 (Subasumstat) upregulated IFNAR1, eliciting Treg fragility and inhibiting tumor growth in an IFNAR1-dependent manner. These findings describe a mechanism by which intratumoral Treg cells retain immunosuppressive activities and suggest therapeutic approaches for inducing Treg fragility and increasing the efficacy of immunotherapies., (©2022 American Association for Cancer Research.)
- Published
- 2022
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4. Tumor factors stimulate lysosomal degradation of tumor antigens and undermine their cross-presentation in lung cancer.
- Author
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Lu Z, Chen J, Yu P, Atherton MJ, Gui J, Tomar VS, Middleton JD, Sullivan NT, Singhal S, George SS, Woolfork AG, Weljie AM, Hai T, Eruslanov EB, and Fuchs SY
- Subjects
- Mice, Humans, Animals, Antigens, Neoplasm, CD8-Positive T-Lymphocytes, Dendritic Cells, Lysosomes, Mice, Inbred C57BL, Tumor Microenvironment, Cross-Priming, Lung Neoplasms metabolism
- Abstract
Activities of dendritic cells (DCs) that present tumor antigens are often suppressed in tumors. Here we report that this suppression is induced by tumor microenvironment-derived factors, which activate the activating transcription factor-3 (ATF3) transcription factor and downregulate cholesterol 25-hydroxylase (CH25H). Loss of CH25H in antigen presenting cells isolated from human lung tumors is associated with tumor growth and lung cancer progression. Accordingly, mice lacking CH25H in DCs exhibit an accelerated tumor growth, decreased infiltration and impaired activation of intratumoral CD8
+ T cells. These mice do not establish measurable long-term immunity against malignant cells that undergo chemotherapy-induced immunogenic cell death. Mechanistically, downregulation of CH25H stimulates membrane fusion between endo-phagosomes and lysosomes, accelerates lysosomal degradation and restricts cross-presentation of tumor antigens in the intratumoral DCs. Administration of STING agonist MSA-2 reduces the lysosomal activity in DCs, restores antigen cross presentation, and increases therapeutic efficacy of PD-1 blockade against tumour challenge in a CH25H-dependent manner. These studies highlight the importance of downregulation of CH25H in DCs for tumor immune evasion and resistance to therapy., (© 2022. The Author(s).)- Published
- 2022
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5. ATF3 and CH25H regulate effector trogocytosis and anti-tumor activities of endogenous and immunotherapeutic cytotoxic T lymphocytes.
- Author
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Lu Z, McBrearty N, Chen J, Tomar VS, Zhang H, De Rosa G, Tan A, Weljie AM, Beiting DP, Miao Z, George SS, Berger A, Saggu G, Diehl JA, Koumenis C, and Fuchs SY
- Subjects
- Immunotherapy, Steroid Hydroxylases, Virus Replication genetics, T-Lymphocytes, Cytotoxic, Trogocytosis
- Abstract
Effector trogocytosis between malignant cells and tumor-specific cytotoxic T lymphocytes (CTLs) contributes to immune evasion through antigen loss on target cells and fratricide of antigen-experienced CTLs by other CTLs. The mechanisms regulating these events in tumors remain poorly understood. Here, we demonstrate that tumor-derived factors (TDFs) stimulated effector trogocytosis and restricted CTLs' tumoricidal activity and viability in vitro. TDFs robustly altered the CTL's lipid profile, including depletion of 25-hydroxycholesterol (25HC). 25HC inhibited trogocytosis and prevented CTL's inactivation and fratricide. Mechanistically, TDFs induced ATF3 transcription factor that suppressed the expression of 25HC-regulating gene-cholesterol 25-hydroxylase (CH25H). Stimulation of trogocytosis in the intratumoral CTL by the ATF3-CH25H axis attenuated anti-tumor immunity, stimulated tumor growth, and impeded the efficacy of chimeric antigen receptor (CAR) T cell adoptive therapy. Through use of armored CAR constructs or pharmacologic agents restoring CH25H expression, we reversed these phenotypes and increased the efficacy of immunotherapies., Competing Interests: Declaration of interests A.B. and G.S. were employees of and stockholders in Millennium Pharmaceuticals, Inc., a wholly owned subsidiary of Takeda Pharmaceutical Company Limited producing TAK981, while engaged in the research project. Z.L., N.M., and S.Y.F. are listed as inventors on The University of Pennsylvania’s patent application related to the matter described in this manuscript., (Copyright © 2022 Elsevier Inc. All rights reserved.)
- Published
- 2022
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6. Targeting PARP11 to avert immunosuppression and improve CAR T therapy in solid tumors.
- Author
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Zhang H, Yu P, Tomar VS, Chen X, Atherton MJ, Lu Z, Zhang HG, Li S, Ortiz A, Gui J, Leu NA, Yan F, Blanco A, Meyer-Ficca ML, Meyer RG, Beiting DP, Li J, Nunez-Cruz S, O'Connor RS, Johnson LR, Minn AJ, George SS, Koumenis C, Diehl JA, Milone MC, Zheng H, and Fuchs SY
- Subjects
- Humans, Immunosuppression Therapy, Immunotherapy, Adoptive, Tumor Microenvironment, Neoplasms drug therapy, Poly(ADP-ribose) Polymerases metabolism, Receptors, Chimeric Antigen genetics
- Abstract
Evasion of antitumor immunity and resistance to therapies in solid tumors are aided by an immunosuppressive tumor microenvironment (TME). We found that TME factors, such as regulatory T cells and adenosine, downregulated type I interferon receptor IFNAR1 on CD8
+ cytotoxic T lymphocytes (CTLs). These events relied upon poly-ADP ribose polymerase-11 (PARP11), which was induced in intratumoral CTLs and acted as a key regulator of the immunosuppressive TME. Ablation of PARP11 prevented loss of IFNAR1, increased CTL tumoricidal activity and inhibited tumor growth in an IFNAR1-dependent manner. Accordingly, genetic or pharmacologic inactivation of PARP11 augmented the therapeutic benefits of chimeric antigen receptor T cells. Chimeric antigen receptor CTLs engineered to inactivate PARP11 demonstrated a superior efficacy against solid tumors. These findings highlight the role of PARP11 in the immunosuppressive TME and provide a proof of principle for targeting this pathway to optimize immune therapies., (© 2022. The Author(s), under exclusive licence to Springer Nature America, Inc.)- Published
- 2022
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7. Temozolomide induces activation of Wnt/β-catenin signaling in glioma cells via PI3K/Akt pathway: implications in glioma therapy.
- Author
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Tomar VS, Patil V, and Somasundaram K
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- Brain Neoplasms drug therapy, Cell Line, Tumor, Drug Resistance, Neoplasm drug effects, Gene Expression Regulation, Neoplastic drug effects, Glioblastoma metabolism, Glioma drug therapy, Glycogen Synthase Kinase 3 metabolism, Humans, Phosphatidylinositol 3-Kinases metabolism, Proto-Oncogene Proteins c-akt metabolism, Temozolomide metabolism, Wnt Proteins metabolism, Xenograft Model Antitumor Assays, beta Catenin metabolism, Glioma metabolism, Temozolomide pharmacology, Wnt Signaling Pathway physiology
- Abstract
Glioblastoma (GBM) is the most aggressive type of glioma. Temozolomide (TMZ) is currently the drug of choice used for post-operative chemotherapy of GBM. However, the presence of intrinsic and acquired resistance hinders the success of chemotherapy. To understand the TMZ resistant mechanisms in glioma, we investigated the alterations in cellular signaling pathways by performing transcriptome analysis of TMZ treated glioma cells. Gene Set Enrichment Analysis (GSEA) indicated a significant enrichment of Wnt/β-catenin signaling besides many other pathways in TMZ treated cells. Further, we demonstrate that TMZ treatment increased the activity from TOPflash reporter, (a Wnt responsive reporter), enhanced the levels of pGSK-3β (S9) and reduced the levels of p-β-catenin (S33/37/T41) with a concomitant increase in transcript and protein levels of Wnt targets in a concentration and time-dependent manner. While TMZ treated cells did not show alteration in any of the Wnt ligands, PI3K inhibitor (LY294002) treatment repressed Akt activation and abolished the TMZ-mediated induction of Wnt/β-catenin pathway. In addition, we show that Wnt/β-catenin signaling activation by TMZ is independent of ATM/Chk2 pathway. Further, we also demonstrate the activation of mTOR pathway after TMZ treatment. Thus, our results demonstrate that activation of Wnt/β-catenin pathway involves an ATM/Chk2- independent PI3K/Akt/GSK-3 cascade in TMZ treated cells and further provides mechanistic basis for the chemoresistance of glioma to TMZ.
- Published
- 2020
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8. The cancer-associated, gain-of-function TP53 variant P152Lp53 activates multiple signaling pathways implicated in tumorigenesis.
- Author
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Singh S, Kumar M, Kumar S, Sen S, Upadhyay P, Bhattacharjee S, M N, Tomar VS, Roy S, Dutt A, and Kundu TK
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- Animals, Cell Line, Tumor, Cell Movement genetics, Cell Proliferation genetics, Female, Gain of Function Mutation, Humans, Lung Neoplasms genetics, Lung Neoplasms metabolism, Lung Neoplasms pathology, Mice, Mice, Nude, Mouth Neoplasms genetics, Mouth Neoplasms metabolism, Mouth Neoplasms pathology, Neoplasm Invasiveness genetics, Polymorphism, Single Nucleotide, Signal Transduction genetics, Transcriptional Activation, Tumor Suppressor Protein p53 metabolism, Xenograft Model Antitumor Assays, Carcinogenesis genetics, Tumor Suppressor Protein p53 genetics
- Abstract
TP53 is the most frequently mutated tumor suppressor gene in many cancers, yet biochemical characterization of several of its reported mutations with probable biological significance have not been accomplished enough. Specifically, missense mutations in TP53 can contribute to tumorigenesis through gain-of-function of biochemical and biological properties that stimulate tumor growth. Here, we identified a relatively rare mutation leading to a proline to leucine substitution (P152L) in TP53 at the very end of its DNA-binding domain (DBD) in a sample from an Indian oral cancer patient. Although the P152Lp53 DBD alone bound to DNA, the full-length protein completely lacked binding ability at its cognate DNA motifs. Interestingly, P152Lp53 could efficiently tetramerize, and the mutation had only a limited impact on the structure and stability of full-length p53. Significantly, when we expressed this variant in a TP53-null cell line, it induced cell motility, proliferation, and invasion compared with a vector-only control. Also, enhanced tumorigenic potential was observed when P152Lp53-expressing cells were xenografted into nude mice. Investigating the effects of P152Lp53 expression on cellular pathways, we found that it is associated with up-regulation of several pathways, including cell-cell and cell-extracellular matrix signaling, epidermal growth factor receptor signaling, and Rho-GTPase signaling, commonly active in tumorigenesis and metastasis. Taken together, our findings provide a detailed account of the biochemical and cellular alterations associated with the cancer-associated P152Lp53 variant and establish it as a gain-of-function TP53 variant., (© 2019 Singh et al.)
- Published
- 2019
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9. Serine/threonine/tyrosine-interacting-like protein 1 (STYXL1), a pseudo phosphatase, promotes oncogenesis in glioma.
- Author
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Tomar VS, Baral TK, Nagavelu K, and Somasundaram K
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- Animals, Apoptosis Regulatory Proteins metabolism, Brain Neoplasms metabolism, Brain Neoplasms therapy, Cell Line, Tumor, Gene Expression Regulation, Neoplastic, Glioma metabolism, Glioma therapy, Humans, Mice, Phosphoric Monoester Hydrolases metabolism, RNAi Therapeutics methods, Xenograft Model Antitumor Assays methods, Apoptosis Regulatory Proteins genetics, Brain Neoplasms genetics, Carcinogenesis genetics, Glioma genetics, Phosphoric Monoester Hydrolases genetics
- Abstract
Phosphatases play an important role in cellular signaling and are often found dysregulated in cancers including glioblastoma (GBM). A comprehensive bioinformatics analysis of phosphatases (n = 403) in multiple datasets revealed their deregulation in GBM. Among the differentially regulated phosphatases (n = 186; 46.1%), majority of them were found to be regulated by microRNA (n = 94; 50.5%) followed by DNA methylation (n = 22; 11.8%) and altered copy number variation (n = 10; 5.37%). STYXL1 (Serine/threonine/tyrosine-interacting-like protein 1) was found to be the second most amplified gene in GBM, upregulated, and correlated to poor prognosis. The expression of STYXL1 was also found to be higher in IDH1 mutant gliomas and G-CIMP- gliomas which are reported to be more aggressive than their corresponding counterparts. Silencing STYXL1 inhibited glioma cell growth, soft agar colony formation, migration, invasion, proliferation, and xenograft tumor growth. Further, ectopic expression of STYXL1 was found to promote glioma cell growth, soft agar colony formation, migration, and RasV12 induced in-vitro transformation of immortalized human astrocytes, thus confirming its oncogenic potential in GBM. In this report, we provide a comprehensive overview of deregulation of phosphatases in GBM and demonstrate for the first time, the oncogenic nature of STYXL1 in GBM. This study might be useful for treatment of GBM patients with deregulated STYXL1., (Copyright © 2019 Elsevier Inc. All rights reserved.)
- Published
- 2019
- Full Text
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10. Haemophilic pseudotumour: surgical management of a rare case.
- Author
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Dutt K, Agarwal PN, Singh R, and Tomar VS
- Abstract
Haemophilia is a common cause of genetically inherited bleeding disorders. Pseudotumours occur in 1-2 % of persons with severe forms of haemophilia. These are a result of repeated haemorrhage into soft tissues, subperiosteum or a site of bone fracture with inadequate resorption of the extravasated blood. There are a number of therapeutic alternatives for this dangerous condition: surgical removal, percutaneous management, irradiation, embolization etc. In this case report, we describe the natural history, clinical course and successful surgical management of a patient with haemophilia who presented with a massive pseudotumour. We also briefly review the relevant literature on the various therapeutic modalities that have been implemented in the management of this rare complication. Though surgeons may be averse to operate on haemophiliacs, primary surgical management as done in our case may prove to be the definitive treatment option for such patients.
- Published
- 2015
- Full Text
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