NOTCH1 Mutations Research Articles

Biofunctional study on chemoresistance in esophageal squamous carcinoma cells induced by missense mutation of NOTCH1 p.E450K.

Neoadjuvant chemotherapy (nCT) combined with surgery is one of the main strategies for the treatment of resectable locally advanced esophageal squamous cell carcinoma (ESCC). However, nearly 40% of patients did not benefit from nCT, and the detection rate of NOTCH1 missense mutation was significantly increased in patients who did not respond to chemotherapy, suggesting that the missense mutation may be related to tumor chemoresistance. We aim to explore the effect of a NOTCH1 missense mutation on cell phenotype, to interpret the biofunctional changes in cell lines with a NOTCH1 missense mutation and to analyze the effect of a NOTCH1 missense mutation on drug resistance in ESCC cell lines. Sanger sequencing was used to evaluate the exon mutations in the NOTCH1 ligand binding region of candidate ESCC cell lines. After screening, KYSE450 and KYSE140 cells were selected as the research objects, and point mutation cell lines [KYSE140-mutant-type (MT) and KYSE450-MT] were constructed by CRISPR/Cas9 technology. Then, functional experiments were performed with the four cell lines [KYSE450-MT/wild-type (WT) and KYSE140-MT/WT]. The drug resistance of ESCC cell lines was assessed with a drug sensitivity test, and the proliferation, invasion and migration of ESCC lines were evaluated by proliferation test, scratch test and Transwell test. The cell cycle status of ESCC cells was assessed using flow cytometry. Drug sensitivity tests showed that the NOTCH1 p.E450K point mutation caused chemotherapy resistance in KYSE140 and KYSE450 ESCC cell lines. Cell proliferation, Wound scratch and Transwell assays showed that the NOTCH1 p.E450K point mutation enhanced the proliferation, invasion and migration abilities of KYSE140 and KYSE450 cells. Flow cytometry analysis showed that the NOTCH1 p.E450K point mutation caused an increase in KYSE140 and KYSE450 cells in S phase. The NOTCH1 p.E450K point mutation causes chemotherapy resistance in KYSE140 and KYSE450 ESCC cells. Cell functional experiments showed that the NOTCH1 p.E450K point mutation enhanced the proliferation, migration and invasion abilities of KYSE140 and KYSE450 cells and increased the number of cells in S phase.

Enlarged perivascular spaces are associated with white matter injury, cognition and inflammation in cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy.

Enlarged perivascular spaces have been previously reported in cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy, but their significance and pathophysiology remains unclear. We investigated associations of white matter enlarged perivascular spaces with classical imaging measures, cognitive measures and plasma proteins to better understand what enlarged perivascular spaces represent in cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy and whether radiographic measures of enlarged perivascular spaces would be of value in future therapeutic discovery studies for cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy. Twenty-four individuals with cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy and 24 age- and sex-matched controls were included. Disease status was determined based on the presence of NOTCH3 mutation. Brain imaging measures of white matter hyperintensity, brain parenchymal fraction, white matter enlarged perivascular space volumes, clinical and cognitive measures as well as plasma proteomics were used in models. White matter enlarged perivascular space volumes were calculated via a novel, semiautomated pipeline, and levels of 7363 proteins were quantified in plasma using the SomaScan assay. The relationship of enlarged perivascular spaces with global burden of white matter hyperintensity, brain atrophy, functional status, neurocognitive measures and plasma proteins was modelled with linear regression models. Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy and control groups did not exhibit differences in mean enlarged perivascular space volumes. However, increased enlarged perivascular space volumes in cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy were associated with increased white matter hyperintensity volume (β = 0.57, P = 0.05), Clinical Dementia Rating Sum-of-Boxes score (β = 0.49, P = 0.04) and marginally with decreased brain parenchymal fraction (β = -0.03, P = 0.10). In interaction term models, the interaction term between cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy disease status and enlarged perivascular space volume was associated with increased white matter hyperintensity volume (β = 0.57, P = 0.02), Clinical Dementia Rating Sum-of-Boxes score (β = 0.52, P = 0.02), Mini-Mental State Examination score (β = -1.49, P = 0.03) and marginally with decreased brain parenchymal fraction (β = -0.03, P = 0.07). Proteins positively associated with enlarged perivascular space volumes were found to be related to leukocyte migration and inflammation, while negatively associated proteins were related to lipid metabolism. Two central hub proteins were identified in protein networks associated with enlarged perivascular space volumes: CXC motif chemokine ligand 8/interleukin-8 and C-C motif chemokine ligand 2/monocyte chemoattractant protein 1. The levels of CXC motif chemokine ligand 8/interleukin-8 were also associated with increased white matter hyperintensity volume (β = 42.86, P = 0.03), and levels of C-C motif chemokine ligand 2/monocyte chemoattractant protein 1 were further associated with decreased brain parenchymal fraction (β = -0.0007, P < 0.01) and Mini-Mental State Examination score (β = -0.02, P < 0.01) and increased Trail Making Test B completion time (β = 0.76, P < 0.01). No proteins were associated with all three studied imaging measures of pathology (brain parenchymal fraction, enlarged perivascular spaces, white matter hyperintensity). Based on associations uncovered between enlarged perivascular space volumes and cognitive functions, imaging and plasma proteins, we conclude that white matter enlarged perivascular space volumes may capture pathologies contributing to chronic brain dysfunction and degeneration in cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy.

Renin-Angiotensin System Inhibitors Suppress the Growth of Leukemia Cells.

The renin-angiotensin system (RAS) regulates blood pressure. The RAS is also related to cell growth, and its activation has been reported in various cancer cells. Therefore, we investigated the effects of RAS inhibitors on the in vitro growth of leukemia cell lines. THP-1, MV4-11, and TMD7 cells derived from acute myeloid leukemia, K-562 cells from chronic myeloid leukemia, and Jurkat and KOPT-K1 cells from T-lymphoblastic leukemia (T-ALL) with NOTCH1 mutations were used. We used four RAS inhibitors: the renin inhibitor aliskiren, angiotensin-converting enzyme 1 inhibitor captopril, angiotensin II type 1 receptor antagonist azilsartan, and angiotensin II type 2 receptor antagonist PD123319. Cells were cultured with the inhibitors and cell growth was assessed using a colorimetric assay. The expression of signaling proteins was assessed using immunoblotting. Treatment with aliskiren, azilsartan, or PD123319 suppressed the growth of all cell lines. Captopril treatment suppressed the growth of K-562, KOPT-K1, and MV4-11 cells. Flow cytometric analysis revealed that the growth suppression was due to the induction of apoptosis. Their suppressive effects on normal lymphocytes were milder than those on leukemia cells. Treatment with these inhibitors decreased MYC expression, induced caspase3 and PARP cleavage, and suppressed mTOR signaling. The treatment also suppressed NOTCH1 signaling in T-ALL cells. RAS inhibitors can be repurposed as molecular-targeted drugs for leukemia. However, the concentrations of the inhibitors were much higher than those in the plasma of patients with hypertension. Therefore, further investigation is required for their clinical use.

Effect of Ferroptosis Inducers and Inhibitors on Cell Proliferation in Acute Leukemia.

Ferroptosis refers to an iron-dependent mechanism of regulated cell death that is attributable to lipid peroxidation. Ferroptosis has been documented as a therapeutic target for various solid cancers; nonetheless, its implication in leukemia remains ambiguous. Therefore, this study aimed at investigating the impact of ferroptosis inducers and inhibitors on in vitro leukemia cell line proliferation. Six leukemia cell lines, including acute myeloid leukemia (AML)-derived MV4-11, THP-1, HL-60, and U-937, and T-lymphoblastic leukemia (T-ALL)-derived Jurkat and KOPT-K1 with activating NOTCH1 mutations, were assessed. Erastin, which interrupts cystine uptake and depletes intracellular glutathione, and RAS-selective lethal 3 (RSL3), which suppresses glutathione peroxidase 4 (GPX4), were employed as ferroptosis inducers. Lipid peroxidation-arresting ferrostatin-1 and deferoxamine were used as ferroptosis inhibitors. Cells were cultured with these compounds and cell proliferation was assessed using a colorimetric assay. Additionally, signaling protein expression was monitored using immunoblotting, and the outcome of GPX4 knockdown was evaluated. Ferroptosis inducers suppressed proliferation in all cell lines except THP-1 for Erastin and THP-1 and Jurkat for RSL3. Although the ferroptosis inhibitors did not affect cell proliferation, they rescued inducer-mediated growth suppression. Ferroptosis inducers impeded MYC and cyclin D3 expression in certain cell lines and NOTCH1 signaling in T-ALL cells. GPX4 knockdown and RSL3 treatment interrupted MYC and cyclin D3 expression, respectively, in four cell lines. Ferroptosis inducers may serve as potential candidates for novel molecular therapy against AML and T-ALL.

First report of a p.Cys484Tyr Notch3 mutation in a CADASIL patient with acute bilateral multiple subcortical infarcts—case report and brief review

BackgroundCADASIL(Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy)is an inherited small vessel disease caused by mutations in NOTCH3 gene. Although NOTCH3 has numerous hotspots of gene mutations, mutations in exons 9 are rare. The p.C484T gene mutation type associated with it has not been reported in any relevant cases yet. Furthermore, CADASIL patients rarely present with acute bilateral multiple subcortical infarcts.Case presentationWe report the case of a Chinese female patient with CADASIL who experienced “an acute bilateral subcortical infarction” because of“hemodynamic changes and hypercoagulability”. In genetic testing, we discovered a new Cys484Tyr mutation in exon 9, which has also been found in the patient’s two daughters.ConclusionsIt is important to note that this discovery not only expands the mutation spectrum of Notch3 mutations in CADASIL patients, but also examines the mechanism behind acute bilateral subcortical infarction in CADASIL patients via case reviews and literature reviews, in order to provide some clinical recommendations for early intervention, diagnosis, and treatment in similar cases in the future.

Protein aggregates containing wild-type and mutant NOTCH3 are major drivers of arterial pathology in CADASIL.

Loss of arterial smooth muscle cells (SMCs) and abnormal accumulation of the extracellular domain of the NOTCH3 receptor (Notch3ECD) are the 2 core features of CADASIL, a common cerebral small vessel disease caused by highly stereotyped dominant mutations in NOTCH3. Yet the relationship between NOTCH3 receptor activity, Notch3ECD accumulation, and arterial SMC loss has remained elusive, hampering the development of disease-modifying therapies. Using dedicated histopathological and multiscale imaging modalities, we could detect and quantify previously undetectable CADASIL-driven arterial SMC loss in the CNS of mice expressing the archetypal Arg169Cys mutation. We found that arterial pathology was more severe and Notch3ECD accumulation greater in transgenic mice overexpressing the mutation on a wild-type Notch3 background (TgNotch3R169C) than in knockin Notch3R170C/R170C mice expressing this mutation without a wild-type Notch3 copy. Notably, expression of Notch3-regulated genes was essentially unchanged in TgNotch3R169C arteries. We further showed that wild-type Notch3ECD coaggregated with mutant Notch3ECD and that elimination of 1 copy of wild-type Notch3 in TgNotch3R169C was sufficient to attenuate Notch3ECD accumulation and arterial pathology. These findings suggest that Notch3ECD accumulation, involving mutant and wild-type NOTCH3, is a major driver of arterial SMC loss in CADASIL, paving the way for NOTCH3-lowering therapeutic strategies.

Williams-Beuren syndrome in pediatric T-cell acute lymphoblastic leukemia: A rare case report and review of literature.

Williams-Beuren syndrome (WBS) is a rare genetic disorder caused by hemizygous microdeletion of contiguous genes on chromosome 7q11.23. Although the phenotype features extensive heterogeneity in severity and performance, WBS is not considered to be a predisposing factor for cancer development. Currently, hematologic cancers, mainly Burkitt lymphoma, are rarely reported in patients with WBS. Here in, we report a unique case of T-cell acute lymphoblastic leukemia in a male child with WBS. This retrospective study analyzed the clinical data of this case receiving chemotherapy were analyzed. This is a retrospective study. The patient, who exhibited a typical WBS phenotype and presented with hemorrhagic spots. Chromosomal genome-wide chip analysis (CMA) revealed abnormalities on chromosomes 7 and 9. The fusion gene STIL-TAL1 and mutations in BCL11B, NOTCH1, and USP7 have also been found and all been associated with the occurrence of T-cell leukemia. The patient responded well to the chemotherapy. To the best of our knowledge, this is the first reported case of WBS in T-cell acute lymphoblastic leukemia. We want to emphasize that the occurrence of leukemia in this patient might be related to the loss of 7q11.23 and microdeletion of 9p21.3 (including 3 TSGs), but the relationship between WBS and malignancy remains unclear. Further studies are required to clarify the relationship between WBS and malignancy.

Alternative mechanisms of Notch activation by partitioning into distinct endosomal domains.

Different membrane microdomain compositions provide unique environments that can regulate signaling receptor function. We identify microdomains on the endosome membrane of Drosophila endosomes, enriched in lipid-raft or clathrin/ESCRT-0, which are associated with Notch activation by distinct, ligand-independent mechanisms. Transfer of Notch between microdomains is regulated by Deltex and Suppressor of deltex ubiquitin ligases and is limited by a gate-keeper role for ESCRT complexes. Ubiquitination of Notch by Deltex recruits it to the clathrin/ESCRT-0 microdomain and enhances Notch activation by an ADAM10-independent/TRPML-dependent mechanism. This requirement for Deltex is bypassed by the downregulation of ESCRT-III. In contrast, while ESCRT-I depletion also activates Notch, it does so by an ADAM10-dependent/TRPML-independent mechanism and Notch is retained in the lipid raft-like microdomain. In the absence of such endosomal perturbation, different activating Notch mutations also localize to different microdomains and are activated by different mechanisms. Our findings demonstrate the interplay between Notch regulators, endosomal trafficking components, and Notch genetics, which defines membrane locations and activation mechanisms.

Abstract A035: Mutation of NOTCH1 is selected within normal esophageal tissues, yet leads to selective epistasis suppressive of further evolution into cancer

Abstract Sequencing of tissues from histologically normal esophagus, among other organs, has revealed that normal tissues acquire somatic variants that are also found in cancers arising from the same tissue types. Our understanding of how somatic mutations that are commonly found in normal tissue can contribute to tumorigenesis is limited: common somatic mutations may or may not confer phenotypes compatible with oncogenesis. However, the strength of selection for somatic variants that appear in both normal and cancer tissues can be quantified in each context using evolutionary modeling approaches. We studied the evolutionary trajectory from normal esophageal tissue to esophageal squamous-cell carcinoma (ESCC) by analysis of sequencing data from previous studies on normal esophageal epithelium and ESCC to reveal the stepwise contributions of somatic mutations to increased cellular division and survival. We also analyzed pairwise selective epistasis between somatically mutated genes that may lead to stepwise substitution patterns. We found that NOTCH1 substitutions are at high prevalence in normal tissue, and scaled selection coefficients indicate that NOTCH1 mutations are highly selected in normal esophageal tissue. In contrast, there is little to no positive selection for NOTCH1 mutations in ESCC, suggesting that NOTCH1 substitutions do not drive tumorigenesis. Indeed, NOTCH1 mutations have recently been shown to favor clonal expansion in normal esophageal tissue. Furthermore, we calculate that mutations in NOTCH1 exhibit antagonistic epistasis with well-known cancer drivers, including TP53, reducing selection for progressive mutations in tumorigenesis. This antagonistic epistasis likely underlies the low likelihood of tumor progression in the presence of NOTCH1 mutations in the esophagus. Citation Format: Kira A. Glasmacher, Vincent L. Cannataro, Jeffrey D. Mandell, Mia Jackson, J. Nic Fisk, Jeffrey P. Townsend. Mutation of NOTCH1 is selected within normal esophageal tissues, yet leads to selective epistasis suppressive of further evolution into cancer [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Translating Cancer Evolution and Data Science: The Next Frontier; 2023 Dec 3-6; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(3 Suppl_2):Abstract nr A035.

Abstract TP280: Monogenetic Stroke Syndrome Testing in Adults: A Single Center Experience

As access and coverage of genetic testing has increased, it is being used more commonly in adults with strokes. However, no clear guidelines exist for who should undergo genetic testing. Our retrospective review aims to provide guidance in this regard and show our experience. Genetic testing was ordered at our comprehensive stroke center between June 2022 and September 2023. Tests were ordered from GeneDx and genetic material was collected by buccal swab after consent was obtained. Most of the testing was done routinely in the outpatient setting, but was rarely performed inpatient when diagnosis would change acute management. Genetic testing was ordered for 41 patients. Tests ordered included whole exome sequencing, mitochondrial genome sequencing, Marfan syndrome and thoracic aortic aneurysm and dissection panel, Disorders of connective tissues panel and expedited whole genome sequencing. Indications for testing included evaluation of carotid and vertebral dissections, recurrent stroke, cryptogenic stroke, and leukoencephalopathy. The average age of tested patients was 47. Of these patients, 6 had not had a stroke and the testing was ordered to evaluate etiology of vertebral or carotid dissections. Of the 35 patients being evaluated for stroke etiology, 60% had at least one stroke or TIA prior to presentation. Of patients tested, 14 had evidence of dissection in the carotid arteries or vertebral arteries. At the time of analysis, 27 patients had results available, of which 15 had negative results. Positive results with pathogenic variant were seen in 4 patients. Pathologic variants detected included mutations in ABCC6, NOTCH3, MT-TL1, HBB, and MCCACHC genes. Variants of unknown significance were seen in 8 patients. These variants included mutations in MYLK, COL5A1, COL5A2, KRIT1, CCM2, XPR1, MT-CYB, MT-ND4, and MT-ATP6 genes. This study highlights that in the right clinical population, like young patients with recurrent stroke, genetic testing can be helpful to elucidate the etiology of cerebrovascular disease when standard stroke work up is inconclusive. With retrospective review, we aim to provide guidance on indications for genetic testing in adults with stroke and dissection.

Abstract IA010: Unraveling mutation and selection to better understand early cancer evolution

Abstract Molecular variants drive tumorigenesis. The degree by which specific molecular variants drive cell proliferation varies between tissues, is dependent upon mutational background within tissues, and also varies along the progression from normal tissue development through cancer growth. Knowledge regarding the magnitude by which variants drive cell proliferation, quantifiable as the scaled selection coefficient or cancer effect size of variants, throughout the trajectory from healthy tissue into cancer informs early cancer evolution, detection, and diagnosis—and also has direct relevance to clinical trials, targeted therapeutics, and basic research prioritization. However, in order to quantify these scaled selection coefficients one must disentangle the prevalence of fixed substitutions from the rate at which they occur within cells—the mutation rate. These mutation rates also vary between tissues, throughout genomes, and over stages of tissue development and carcinogenesis within the same tissue lineage. Here, we present a novel methodology to quantify scaled selection coefficients in a stepwise manner over several discrete steps in tissue evolution and tumorigenesis. We highlight results from ongoing work in two tissue types: the esophagus and the endometrium. Within the normal esophagus and esophageal squamous cell carcinoma we find that mutation rates vary substantially along the trajectory from embryogenesis through normal tissue and from normal tissue through tumorigenesis. Accordingly, we also find that selective advantages vary between these steps of evolution, with variants of NOTCH1, NOTCH2, and FAT1 having measurable proliferative advantage within normal tissues but no detectable proliferative advantage during tumorigenesis, and variants of PIK3CA, TP53, NFE2L2, and FBXW7 being selected to fix within both normal and tumorigenic tissues. Intriguingly, we complement this analysis with a quantification of pairwise epistasis and find that mutation of NOTCH1 decreases the selective advantage of variants within TP53 and other drivers, informing recent research suggesting NOTCH1 substitutions may actively inhibit tumorigenesis. We similarly deconvolute mutation and selection between embryogenesis through atypical hyperplasia of the endometrium and atypical hyperplasia through Stage 1 endometrial carcinoma and find that variants within CTNNB1 and PTEN have higher selective advantage within hyperplasia, whereas variants within ARID1A and PIK3R1 are more highly selected through Stage 1 tumorigenesis. Overall, we demonstrate how accounting for differences in mutational processes and rates among discrete steps in tumorigenesis and epistatic interactions allows one to determine which variants are contributing to clonal expansion within normal tissues, which variants are contributing to tumorigenesis, which variants are important to both, and in certain instances which variants may impede the progression of a tumor. Citation Format: Vincent L. Cannataro, Kira A. Glasmacher, Mary Summers, Jeffrey D. Mandell, J. Nic Fisk, Mia Jackson, Sem Asmelash, Jeffrey P. Townsend. Unraveling mutation and selection to better understand early cancer evolution [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Translating Cancer Evolution and Data Science: The Next Frontier; 2023 Dec 3-6; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(3 Suppl_2):Abstract nr IA010.

Abstract TMP67: Cerebral Autosomal Dominant Arteriopathy With Subcortical Infarcts and Leukoencephalopathy May Affect Large Cerebral Arteries

Introduction: CADASIL is the most common monogenic small-vessel disease (SVD) form. Large and small brain arteries are intimately related, but it is unclear whether people with CADASIL have changes in their large arteries as a result. We hypothesized that CADASIL patients have affected large arteries compared to controls. Methods: We conducted a comparative analysis by matching 37 CADASIL patients with 104 lacunar stroke patients from the NYP/ Columbia University Medical Center Stroke Registry Study matched by age +/-3 and sex. We measured the basilar and intracranial carotid artery diameters in both groups in T2 MRI images. We rated cervical artery tortuosity as 0 for no tortuosity, 1 for 45-90°, and 2 for &gt;90°. We ran generalized linear models to compare cases and controls, adjusting for demographics and clinical variables. Results: Patients with CADASIL were less likely Hispanic\Latino (10.8% vs. 51.9%, p=&lt;0.001), hypertensive (27% vs. 73.1%, p=&lt;0.001), current smokers (5.4%vs. 22.1%, p=0.024), but more likely to have a prior stroke (56.8% vs. 24%, p=&lt;0.001) than controls—Table 1. In the adjusted model, patients with CADASIL had larger basilar artery diameters (p=0.007) and a statistical trend for greater cervical carotid artery tortuosity—Table 2. Conclusions: Although traditionally considered an example of pure SVD, patients with CADASIL have a higher prevalence of cervical tortuosity and intracranial artery dilatation. Whether changes in large arteries result from small artery disease or part of the NOTCH3 mutation phenotype is uncertain. Further investigation is needed to determine if large artery involvement influences the clinical manifestations of CADASIL.

Thymic-Epithelial-Cell-Dependent Microenvironment Influences Proliferation and Apoptosis of Leukemic Cells.

T-cell acute lymphoblastic leukemia (T-ALL) is a hematological cancer characterized by the infiltration of immature T-cells in the bone marrow. Aberrant NOTCH signaling in T-ALL is mainly triggered by activating mutations of NOTCH1 and overexpression of NOTCH3, and rarely is it linked to NOTCH3-activating mutations. Besides the known critical role of NOTCH, the nature of intrathymic microenvironment-dependent mechanisms able to render immature thymocytes, presumably pre-leukemic cells, capable of escaping thymus retention and infiltrating the bone marrow is still unclear. An important challenge is understanding how leukemic cells shape their tumor microenvironment to increase their ability to infiltrate and survive within. Our previous data indicated that hyperactive NOTCH3 affects the CXCL12/CXCR4 system and may interfere with T-cell/stroma interactions within the thymus. This study aims to identify the biological effects of the reciprocal interactions between human leukemic cell lines and thymic epithelial cell (TEC)-derived soluble factors in modulating NOTCH signaling and survival programs of T-ALL cells and TECs. The overarching hypothesis is that this crosstalk can influence the progressive stages of T-cell development driving T-cell leukemia. Thus, we investigated the effect of extracellular space conditioned by T-ALL cell lines (Jurkat, TALL1, and Loucy) and TECs and studied their reciprocal regulation of cell cycle and survival. In support, we also detected metabolic changes as potential drivers of leukemic cell survival. Our studies could shed light on T-cell/stroma crosstalk to human leukemic cells and propose our culture system to test pharmacological treatment for T-ALL.

The genetic and immune features of salivary gland secretory carcinoma with high-grade transformation.

To compare the clinicopathological, molecular, and immune features of conventional and high-grade transformation (HGT) secretory carcinoma (SC) in salivary glands. The clinicopathological data of 88 cases including 74 conventional SCs and 14 SCs with HGT were reviewed. Targeted next-generation sequencing was performed in 11 SCs with HGT and 7 conventional SCs. The level of PD-L1 and CD8+ TILs was determined by immunohistochemistry. Compared with the conventional group, the rates of nodal metastasis, local recurrence, distant metastasis and mortality were significantly higher in the HGT cohort. Mutations of ARID1A/B, KMT2A, HOXD13, NRG1 and ETV6 genes were identified in HGT SCs. A recurrent E307G mutation in GATA6 gene was also observed in two cases. Two deceased HGT patients with distant metastasis harboured NOTCH3 mutations. ETV6-RET translocation was prone to occur in the HGT SCs. Additionally, PD-L1 expression was low, and CD8+ TILs were sparse in most HGT cases. Our findings reveal novel gene alterations involved in the progression of HGT in SCs. Most HGT SCs patients cannot benefit from PD-L1 blocking and may be approached with a distinct treatment strategy including the lymph node dissection and application of molecular target drugs in precision oncology.

Genomic alteration in sporadic adolescent and young adult-onset colorectal adenocarcinoma.

154 Background: Colorectal cancer (CRC) incidence is increasing in adults younger than 50 years. This study evaluated genomic alteration in adolescent and young adult (AYA)-onset sporadic CRC patients who aged between 15 and 39 years. Methods: DNA from 90 archived formalin-fixed, paraffin-embedded (FFPE) tissue samples that histologically confirmed adenocarcinoma with proficient mismatch repair tumors at Siriraj Hospital (Bangkok, Thailand) were extracted. Patients who clinically suspected familial adenomatous polyposis were excluded. Gene mutational analysis was performed by next-generation sequencing (NGS) using an Oncomine Comprehensive Assay Plus kit (Thermo Fisher Scientific, Inc., Waltham, MA, USA) and compared with previous reported molecular data in adult-onset CRC from our group. Results: The top 5 mutations frequency observed were TP53, KRAS, FBXW7, PIK3CA, and SMAD4 mutations which were comparable to what reported in adult-onset CRC. However, FBXW7, PIK3CA, NOTCH1, FGFR3, ERBB2, and PTEN were reported more frequent in AYA group. No difference in number of KRAS, NRAS, and BRAF mutations among 2 groups. Table below shows key cancer genes mutation frequencies. Conclusions: This study is the comprehensive report hotspot mutations using NGS in sporadic AYA-onset sporadic CRC patients. The most commonly identified gene mutation frequencies among AYA-onset were similar to those reported in adult-onset, except for FBXW7, PIK3CA, NOTCH1, FGFR3, ERBB2, and PTEN mutations that had a slightly higher frequency. Further studies on larger sample set for genetic and epigenetic landscape are required. [Table: see text]

Progress to Clarify How NOTCH3 Mutations Lead to CADASIL, a Hereditary Cerebral Small Vessel Disease.

Notch signaling is conserved in C. elegans, Drosophila, and mammals. Among the four NOTCH genes in humans, NOTCH1, NOTCH2, and NOTCH3 are known to cause monogenic hereditary disorders. Most NOTCH-related disorders are congenital and caused by a gain or loss of Notch signaling activity. In contrast, cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) caused by NOTCH3 is adult-onset and considered to be caused by accumulation of the mutant NOTCH3 extracellular domain (N3ECD) and, possibly, by an impairment in Notch signaling. Pathophysiological processes following mutant N3ECD accumulation have been intensively investigated; however, the process leading to N3ECD accumulation and its association with canonical NOTCH3 signaling remain unknown. We reviewed the progress in clarifying the pathophysiological process involving mutant NOTCH3.

CAD204520 Targets NOTCH1 PEST Domain Mutations in Lymphoproliferative Disorders.

NOTCH1 PEST domain mutations are often seen in hematopoietic malignancies, including T-cell acute lymphoblastic leukemia (T-ALL), chronic lymphocytic leukemia (CLL), splenic marginal zone lymphoma (SMZL), mantle cell lymphoma (MCL), and diffuse large B-cell lymphoma (DLBCL). These mutations play a key role in the development and progression of lymphoproliferative tumors by increasing the Notch signaling and, consequently, promoting cell proliferation, survival, migration, and suppressing apoptosis. There is currently no specific treatment available for cancers caused by NOTCH1 PEST domain mutations. However, several NOTCH1 inhibitors are in development. Among these, inhibition of the Sarco-endoplasmic Ca2+-ATPase (SERCA) showed a greater effect in NOTCH1-mutated tumors compared to the wild-type ones. One example is CAD204520, a benzimidazole derivative active in T-ALL cells harboring NOTCH1 mutations. In this study, we preclinically assessed the effect of CAD204520 in CLL and MCL models and showed that NOTCH1 PEST domain mutations sensitize cells to the anti-leukemic activity mediated by CAD204520. Additionally, we tested the potential of CAD204520 in combination with the current first-line treatment of CLL, venetoclax, and ibrutinib. CAD204520 enhanced the synergistic effect of this treatment regimen only in samples harboring the NOTCH1 PEST domain mutations, thus supporting a role for Notch inhibition in these tumors. In summary, our work provides strong support for the development of CAD204520 as a novel therapeutic approach also in chronic lymphoproliferative disorders carrying NOTCH1 PEST domain mutations, emerging as a promising molecule for combination treatment in this aggressive subset of patients.

Genetic and prognostic analysis of blastoid and pleomorphic mantle cell lymphoma: a multicenter analysis in China.

Blastoid or pleomorphic mantle cell lymphoma (B/P-MCL) is characterized by high invasiveness and unfavorable outcomes, which is still a challenge for treating MCL. This retrospective study was performed to comprehensively analyze the clinical, genomic characteristics and treatment options of patients with B/PMCL from multicenter in China. Data were obtained from 693 patients with B/PMCL from three centers in China between April 1999 and December 2019. Seventy-four patients with BMCL (n = 43) or PMCL (n = 31) were included in the analysis. The median age of the cohort was 60.0years with a male-to-female ratio of 2.89:1. The 3-year progression-free survival (PFS) and overall survival (OS) rates were 44.1% and 46.0%, respectively. Mutations of TP53, ATM, NOTCH1, NOTCH2, NSD2, SMARCA4, CREBBP, KMT2D, FAT1, and TRAF2 genes were the most common genetic changes in B/P-MCL. Progression of disease within 12months (POD12) could independently predict the poor prognosis of patients with blastoid and pleomorphic variants. Patients with POD12 carried a distinct mutation profile (TP53, SMARCA4, NSD2, NOTCH2, KMT2D, PTPRD, CREBBP, and CDKN2A mutations) compared to patients with non-POD12. First-line high-dose cytosine arabinoside exposure obtained survival benefits in these populations, and BTKi combination therapy as the front-line treatment had somewhat improvement in survival with no significant difference in the statistic. In conclusion, B/P-MCL had inferior outcomes and a distinct genomic profile. Patients with POD12 displayed a distinct mutation profile and a poor prognosis. New therapeutic drugs and clinical trials for B/P-MCL need to be further explored.

Analysis of Notch1 protein expression in methotrexate-associated lymphoproliferative disorders.

Methotrexate (MTX)-associated lymphoproliferative disorder (MTX-LPD) is a lymphoproliferative disorder in patients treated with MTX. The mechanism of pathogenesis is still elusive, but it is thought to be a complex interplay of factors, such as underlying autoimmune disease activity, MTX use, Epstein-Barr virus infection, and aging. The NOTCH genes encode receptors for a signaling pathway that regulates various fundamental cellular processes, such as proliferation and differentiation during embryonic development. Mutations of NOTCH1 have been reported in B-cell tumors, including chronic lymphocytic leukemia/lymphoma, mantle cell lymphoma, and diffuse large B-cell lymphoma (DLBCL). Recently, it has also been reported that NOTCH1 mutations are found in post-transplant lymphoproliferative disorders, and in CD20-positive cells in angioimmunoblastic T-cell lymphoma, which might be associated with lymphomagenesis in immunodeficiency. In this study, to investigate the association of NOTCH1 in the pathogenesis of MTX-LPD, we evaluated protein expression of Notch1 in nuclei immunohistochemically in MTX-LPD cases [histologically DLBCL-type (n = 24) and classical Hodgkin lymphoma (CHL)-type (n = 24)] and de novo lymphoma cases [DLBCL (n = 19) and CHL (n = 15)]. The results showed that among MTX-LPD cases, the expression of Notch1 protein was significantly higher in the DLBCL type than in the CHL type (P < 0.001). In addition, among DLBCL morphology cases, expression of Notch1 tended to be higher in MTX-LPD than in the de novo group; however this difference was not significant (P = 0.0605). The results showed that NOTCH1 may be involved in the proliferation and tumorigenesis of B cells under the use of MTX. Further research, including genetic studies, is necessary.

Mutant NOTCH3ECD Triggers Defects in Mitochondrial Function and Mitophagy in CADASIL Cell Models.

Cerebral autosomal-dominant arteriopathy with subcortical infarction and leukoencephalopathy (CADASIL) is an inherited small-vessel disease that affects the white matter of the brain. Recent studies have confirmed that the deposition of NOTCH3ECD is the main pathological basis of CADASIL; however, whether different mutations present the same pathological characteristics remains to be further studied. Some studies have found that mitochondrial dysfunction is related to CADASIL; however, the specific effects of NOTCH3ECD on mitochondrial remain to be determined. We aimed to explore the role of mitochondrial dysfunction in CADASIL. We established transgenic human embryonic kidney-293T cell models (involving alterations in cysteine and non-cysteine residues) via lentiviral transfection. Mitochondrial function and structure were assessed using flow cytometry and transmission electron microscopy, respectively. Mitophagy was assessed using western blotting and immunofluorescence. We demonstrated that NOTCH3ECD deposition affects mitochondrial morphology and function, and that its protein levels are significantly correlated with mitochondrial quality and can directly bind to mitochondria. Moreover, NOTCH3ECD deposition promoted the induction of autophagy and mitophagy. However, these processes were impaired, leading to abnormal mitochondrial accumulation. This study revealed a common pathological feature of NOTCH3ECD deposition caused by different NOTCH3 mutations and provided new insights into the role of NOTCH3ECD in mitochondrial dysfunction and mitophagy.