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result(s) for
"Tandon, Mayank"
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ZBP1 not RIPK1 mediates tumor necroptosis in breast cancer
2021
Tumor necrosis happens commonly in advanced solid tumors. We reported that necroptosis plays a major role in tumor necrosis. Although several key necroptosis regulators including receptor interacting protein kinase 1 (RIPK1) have been identified, the regulation of tumor necroptosis during tumor development remains elusive. Here, we report that Z-DNA-binding protein 1 (ZBP1), not RIPK1, mediates tumor necroptosis during tumor development in preclinical cancer models. We found that ZBP1 expression is dramatically elevated in necrotic tumors. Importantly, ZBP1, not RIPK1, deletion blocks tumor necroptosis during tumor development and inhibits metastasis. We showed that glucose deprivation triggers ZBP1-depedent necroptosis in tumor cells. Glucose deprivation causes mitochondrial DNA (mtDNA) release to the cytoplasm and the binding of mtDNA to ZBP1 to activate MLKL in a BCL-2 family protein, NOXA-dependent manner. Therefore, our study reveals ZBP1 as the key regulator of tumor necroptosis and provides a potential drug target for controlling tumor metastasis.
Tumour necroptosis is regulated by RIPK3 during tumour development. Here the authors show that ZBP1 is an upstream mediator of RIPK3 in tumour necroptosis and that glucose deprivation induces the release of mitochondrial DNA, which binds to ZBP1 to activate ZBP1-mediated necroptosis in breast cancer.
Journal Article
The Majority of MicroRNAs Detectable in Serum and Saliva Is Concentrated in Exosomes
2012
There is an increasing interest in using microRNAs (miRNA) as biomarkers in autoimmune diseases. They are easily accessible in many body fluids but it is controversial if they are circulating freely or are encapsulated in microvesicles, particularly exosomes. We investigated if the majority of miRNas in serum and saliva are free-circulating or concentrated in exosomes. Exosomes were isolated by ultracentrifugation from fresh and frozen human serum and saliva. The amount of selected miRNAs extracted from the exosomal pellet and the exosome-depleted serum and saliva was compared by quantitative RT-PCR. Some miRNAs tested are ubiquitously expressed, others were previously reported as biomarkers. We included miRNAs previously reported to be free circulating and some thought to be exosome specific. The purity of exosome fraction was confirmed by electronmicroscopy and western blot. The concentration of miRNAs was consistently higher in the exosome pellet compared to the exosome-depleted supernatant. We obtained the same results using an equal volume or equal amount of total RNA as input of the RT-qPCR. The concentration of miRNA in whole, unfractionated serum, was between the exosomal pellet and the exosome-depleted supernatant. Selected miRNAs, which were detectable in exosomes, were undetectable in whole serum and the exosome-depleted supernantant. Exosome isolation improves the sensitivity of miRNA amplification from human biologic fluids. Exosomal miRNA should be the starting point for early biomarker studies to reduce the probability of false negative results involving low abundance miRNAs that may be missed by using unfractionated serum or saliva.
Journal Article
The genomic landscape of Mongolian hepatocellular carcinoma
2020
Mongolia has the highest incidence of hepatocellular carcinoma (HCC) in the world, but its causative factors and underlying tumor biology remain unknown. Here, we describe molecular characteristics of HCC from 76 Mongolian patients by whole-exome and transcriptome sequencing. We present a comprehensive analysis of mutational signatures, driver genes, and molecular subtypes of Mongolian HCC compared to 373 HCC patients of different races and ethnicities and diverse etiologies. Mongolian HCC consists of prognostic molecular subtypes similar to those found in patients from other areas of Asia, Europe, and North America, as well as other unique subtypes, suggesting the presence of distinct etiologies linked to Mongolian patients. In addition to common driver mutations (TP53, CTNNB1) frequently found in pan-cancer analysis, Mongolian HCC exhibits unique drivers (most notably GTF2IRD2B, PNRC2, and SPTA1), the latter of which is associated with hepatitis D viral infection. These results suggest the existence of new molecular mechanisms at play in Mongolian hepatocarcinogenesis.
Mongolia has the highest incidence of—and mortality from—hepatocellular carcinoma (HCC) in the world. Here, the authors examine the genomic and transcriptomic landscape of Mongolian HCC, uncover novel driver mutations, and suggest distinct disease etiologies.
Journal Article
Inhibition of JAK-STAT pathway corrects salivary gland inflammation and interferon driven immune activation in Sjögren’s disease
by
Nakamura, Hiroyuki
,
Burbelo, Peter
,
Khavandgar, Zohreh
in
Adult
,
Antirheumatic Agents
,
Autoimmune Diseases
2024
ObjectivesInflammatory cytokines that signal through the Janus kinases–signal transducer and activator of transcription (JAK-STAT) pathway, especially interferons (IFNs), are implicated in Sjögren’s disease (SjD). Although inhibition of JAKs is effective in other autoimmune diseases, a systematic investigation of IFN-JAK-STAT signalling and the effect of JAK inhibitor (JAKi) therapy in SjD-affected human tissues has not been fully investigated.MethodsHuman minor salivary glands (MSGs) and peripheral blood mononuclear cells (PBMCs) were investigated using bulk or single-cell (sc) RNA sequencing (RNAseq), immunofluorescence (IF) microscopy and flow cytometry. Ex vivo culture assays on PBMCs and primary salivary gland epithelial cell (pSGEC) lines were performed to model changes in target tissues before and after JAKi.ResultsRNAseq and IF showed activated JAK-STAT pathway in SjD MSGs. Elevated IFN-stimulated gene (ISGs) expression associated with clinical variables (eg, focus scores, anti-SSA positivity). scRNAseq of MSGs exhibited cell type-specific upregulation of JAK-STAT and ISGs; PBMCs showed similar trends, including markedly upregulated ISGs in monocytes. Ex vivo studies showed elevated basal pSTAT levels in SjD MSGs and PBMCs that were corrected with JAKi. SjD-derived pSGECs exhibited higher basal ISG expressions and exaggerated responses to IFN-β, which were normalised by JAKi without cytotoxicity.ConclusionsSjD patients’ tissues exhibit increased expression of ISGs and activation of the JAK-STAT pathway in a cell type-dependent manner. JAKi normalises this aberrant signalling at the tissue level and in PBMCs, suggesting a putative viable therapy for SjD, targeting both glandular and extraglandular symptoms. Predicated on these data, a phase Ib/IIa randomised controlled trial to treat SjD with tofacitinib was initiated.
Journal Article
Generation of murine tumor models refractory to αPD-1/-L1 therapies due to defects in antigen processing/presentation or IFNγ signaling using CRISPR/Cas9
by
Chariou, Paul L.
,
Chari, Raj
,
Gameiro, Sofia R.
in
Animal models
,
Animals
,
Antigen Presentation
2024
Immune checkpoint blockade (ICB) targeting the programmed cell death protein 1 (PD-1) and its ligand 1 (PD-L1) fails to provide clinical benefit for most cancer patients due to primary or acquired resistance. Drivers of ICB resistance include tumor antigen processing/presentation machinery (APM) and IFNγ signaling mutations. Thus, there is an unmet clinical need to develop alternative therapies for these patients. To this end, we have developed a CRISPR/Cas9 approach to generate murine tumor models refractory to PD-1/-L1 inhibition due to APM/IFNγ signaling mutations. Guide RNAs were employed to delete B2m , Jak1 , or Psmb9 genes in ICB-responsive EMT6 murine tumor cells. B2m was deleted in ICB-responsive MC38 murine colon cancer cells. We report a detailed development and validation workflow including whole exome and Sanger sequencing, western blotting, and flow cytometry to assess target gene deletion. Tumor response to ICB and immune effects of gene deletion were assessed in syngeneic mice. This workflow can help accelerate the discovery and development of alternative therapies and a deeper understanding of the immune consequences of tumor mutations, with potential clinical implications.
Journal Article
IL 15 enhances preclinical efficacy of anti-core 1 O-glycans monoclonal antibody NEO-201 against human endometrial and ovarian cancer
by
Hernandez, Lidia
,
Arlen, Philip M.
,
Edmondson, Elijah F.
in
Animals
,
Antibodies, Monoclonal - pharmacology
,
Antibodies, Monoclonal, Humanized - pharmacology
2026
Resistance of gynecological cancers to immunotherapy is due to their ability to impair the cytotoxic activity of immune cells. One strategy to overcome this resistance is the combination of different types of immunotherapies with different mechanisms of action and different targets. The disruption of O-glycosylation pathway in ovarian and endometrial cancer is associated with cancer growth, metastasis, and poor prognosis.
In this study we treated
endometrial and ovarian human cancer cell lines with the combination of the monoclonal antibody (mAb) NEO-201 and IL-15 to overcome the resistance of gynecological cancers to immunotherapy. The combination was also used
to treat mice bearing human ovarian cancer. NEO-201 is a humanized IgG1 mAb that binds to core 1 and/or extended core 1 O-glycans expressed by human cancer cells (including different ovarian cancer subtypes), as well as non-cancerous CD15
granulocytes and immunosuppressive cells. NEO-201 can mediate the killing of its target cells through different mechanisms of action, including antibody-dependent cell-mediated cytotoxicity (ADCC) and complement-dependent cytotoxicity (CDC). One strategy to enhance ADCC mediated by mAbs is to boost natural killer (NK) cells with IL-15. A previous study showed that IL-15 superagonist complex (N-803) enhanced ADCC activity mediated by NEO-201
against several human carcinoma cells, by modulating NK cells activation and cytotoxicity.
In this study we demonstrated that IL-15 enhanced ADCC mediated by NEO-201
against human endometrial and ovarian cancer cell lines expressing NEO-201 target antigen, and that the combination of IL-15 and NEO-201, using purified human NK cells as effectors, had a modest effect in prolonging the survival of mice bearing human ovarian cancer, compared to IL-15 or NEO-201 alone.
The ability of IL-15 to enhance NEO-201 efficacy, with NK cells as effectors, supports the hypothesis of combining NEO-201 and IL-15 with NK cell therapy (i.e. IL-15-secreting CAR-NK cells with a longer IL-15
half-life and stronger NK activity) for the treatment of gynecological cancers expressing O-glycans recognized by NEO-201.
Journal Article
MAFDash: An easy-to-use dashboard builder for mutation data version 1; peer review: 2 not approved
2022
Characterizing the somatic mutation landscape of a cohort of patients has become a routine task in cancer research in recent years. Such studies are often highly interdisciplinary, requiring iterative analysis that must be evaluated at each step by many researchers. Therefore, there is a growing need for reporting tools that can easily generate interactive reports for sharing data and results with collaborators. Here we present an R package, MAFDash, that tries to simplify summarization and visualization of mutation data from Mutation Annotation Format (MAF) files. The output HTML dashboard is a self-contained report that can be used for downstream analysis and sharing results. MAFDash is freely available on Github (https://github.com/CCBR/MAFDash).
Journal Article
Distinct roles of treatment schemes and BRCA2 on the restoration of homologous recombination DNA repair and PARP inhibitor resistance in ovarian cancer
2022
Poly (ADP-ribose) polymerase inhibitors (PARPis) represent a major advance in ovarian cancer, now as a treatment and as a maintenance therapy in the upfront and recurrent settings. However, patients often develop resistance to PARPis, underlining the importance of dissecting resistance mechanisms. Here, we report different dosing/timing schemes of PARPi treatment in
BRCA2
-mutant PEO1 cells, resulting in the simultaneous development of distinct resistance mechanisms. PARPi-resistant variants PEO1/OlaJR, established by higher initial doses and short-term PARPi treatment, develops PARPi resistance by rapidly restoring functional BRCA2 and promoting drug efflux activity. In contrast, PEO1/OlaR, developed by lower initial doses with long-term PARPi exposure, shows no regained BRCA2 function but a mesenchymal-like phenotype with greater invasion ability, and exhibits activated ATR/CHK1 and suppressed EZH2/MUS81 signaling cascades to regain HR repair and fork stabilization, respectively. Our study suggests that PARPi resistance mechanisms can be governed by treatment strategies and have a molecular basis on BRCA2 functionality. Further, we define different mechanisms that may serve as useful biomarkers to assess subsequent treatment strategies in PARPi-resistant ovarian cancer.
Journal Article
A Phase II Study of Pembrolizumab in Combination with Capecitabine and Oxaliplatin with Molecular Profiling in Patients with Advanced Biliary Tract Carcinoma
by
Duffy, Austin G
,
Ma, Lichun
,
Budhu, Anuradha
in
Adult
,
Analysis
,
Antibodies, Monoclonal, Humanized
2022
Abstract
Background
We conducted a phase II study of the combination of pembrolizumab with capecitabine and oxaliplatin (CAPOX) in patients with advanced biliary tract carcinoma (BTC) to assess response rate and clinical efficacy. Exploratory objectives included correlative studies of immune marker expression, tumor evolution, and immune infiltration in response to treatment.
Patients and Methods
Adult patients with histologically confirmed BTC were enrolled and received oxaliplatin and pembrolizumab on day 1 of cycles 1-6. Capecitabine was administered orally twice daily as intermittent treatment, with the first dose on day 1 and the last dose on day 14 of cycles 1-6. Starting on cycle 7, pembrolizumab monotherapy was continued until disease progression. The primary endpoint was progression-free survival (PFS). Secondary endpoints were safety, tolerability, feasibility, and response rate. Immunohistochemistry (IHC) for PD-L1 and immune infiltrates was analyzed in paired tumor biopsies, as well as bulk transcriptome and exome profiling for five patients and single-cell RNA sequencing for one partial responder.
Results
Eleven patients enrolled, three of whom had received no prior systemic therapy. Treatment was well tolerated, and the most common treatment-related grade 3 or 4 adverse events were lymphocytopenia, anemia, and decreased platelet count. Three patients (27.3%) achieved a partial response, and six (54%) had stable disease. The disease control rate was 81.8%. The median PFS was 4.1 months with a 6-month PFS rate of 45.5%. Molecular profiling suggests qualitative differences in immune infiltration and clonal evolution based on response.
Conclusion
Capecitabine and oxaliplatin in combination with pembrolizumab is tolerable and a potentially effective treatment for refractory advanced BTC. This study highlights a design framework for the precise characterization of individual BTC tumors.
Trial Registration
This study was registered in ClinicalTrials.gov (NCT03111732).
This article reports results of a phase II study of the combination of pembrolizumab with capecitabine and oxaliplatin in patients with advanced biliary tract carcinoma to assess response rate and clinical efficacy.
Journal Article
Generation of murine tumor models refractory to alphaPD-1/-L1 therapies due to defects in antigen processing/presentation or IFNgamma signaling using CRISPR/Cas9
2024
Immune checkpoint blockade (ICB) targeting the programmed cell death protein 1 (PD-1) and its ligand 1 (PD-L1) fails to provide clinical benefit for most cancer patients due to primary or acquired resistance. Drivers of ICB resistance include tumor antigen processing/presentation machinery (APM) and IFN[gamma] signaling mutations. Thus, there is an unmet clinical need to develop alternative therapies for these patients. To this end, we have developed a CRISPR/Cas9 approach to generate murine tumor models refractory to PD-1/-L1 inhibition due to APM/IFN[gamma] signaling mutations. Guide RNAs were employed to delete B2m, Jak1, or Psmb9 genes in ICB-responsive EMT6 murine tumor cells. B2m was deleted in ICB-responsive MC38 murine colon cancer cells. We report a detailed development and validation workflow including whole exome and Sanger sequencing, western blotting, and flow cytometry to assess target gene deletion. Tumor response to ICB and immune effects of gene deletion were assessed in syngeneic mice. This workflow can help accelerate the discovery and development of alternative therapies and a deeper understanding of the immune consequences of tumor mutations, with potential clinical implications.
Journal Article