CoChat
Sign Up
Cited by 41

The DOI matches its Crossref record; 2 of the 2 references it cites were found in a registry or an index.

Exosome‐mediated uptake of mast cell tryptase into the nucleus of melanoma cells: a novel axis for regulating tumor cell proliferation and gene expression

Rabelo Melo, Fabio, Santosh Martin, Sebastin, Sommerhoff, Christian P., Pejler, Gunnar·2019·Cell Death & Disease
DOI 10.1038/s41419-019-1879-4PMC PMC6736983
Open this paper in CoChat — free account

Abstract

It is well established that mast cell accumulation accompanies most malignancies. However, the knowledge of how mast cells functionally impact on tumors is still rudimentary. Here we addressed this issue and show that mast cells have anti-proliferative activity on melanoma cells and that this effect is dependent on tryptase, a tetrameric protease stored in mast cell granules. Mechanistically, tryptase was found to be endocytosed by melanoma cells as cargo of DNA-coated exosomes released from melanoma cells, followed by transport to the nucleus. In the nucleus, tryptase executed clipping of histone 3 and degradation of Lamin B1, accompanied by extensive nuclear remodeling. Moreover, tryptase degraded hnRNP A2/B1, a protein involved in mRNA stabilization and interaction with non-coding RNAs. This was followed by downregulated expression of the oncogene EGR1 and of multiple non-coding RNAs, including oncogenic species. Altogether, these findings establish a new principle for regulation of tumor cell proliferation.

Overview

The claims and statistics of this paper haven’t been checked yet.

Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.

A few free checks a day · papers already verified open instantly · results are public

Integrity signals

Registry

Crossref · 10.1038/s41419-019-1879-4

Cites

2 of 2 references verified0 citation errors · 0 not checkable

Statistics

Figures

Fig. 1 Mast cell tryptase suppresses melanoma cell expansion and deliver tryptase into the nucleus of melanoma cells. WT (a) or tryptase-deficient (mMCP6−/−) (b) mouse mast cells were co-cultured with mouse melanoma cells (B16F10) at the ratios indicated, followed by quantification of viable cells using Trypan Blue exclusion. c After co-culture, melanoma cells were separated from mast cells and were analyzed by Western blotting for cell-associated tryptase (mMCP6), CPA3, and core histones H2B, H3, H2A, and H4. Actin was used as loading control. d After co-culture of mast cells and melanoma cells, cells were harvested and analyzed by qPCR for expression of melanoma markers DCT and GP100. The displayed results are from individual experiments, representative of at least three experiments. Data in (a) and (d) are given as mean values ± SEM; *p ≤ 0.05, **p ≤ 0.01, ***p ≤ 0.001. e Confocal microscopy image showing physical contact between mast cells (MC) and melanoma cells (Mel) after co-culture. f, g Controls showing mast cells (f) and melanoma cells (g) alone. h, i Confocal images were analyzed with IMARIS software to generate 3-D-images of the interaction between mast cells and melanoma cells. Note the presence of mast cell tryptase in the nucleus of melanoma cells after mast cell:melanoma cell co-culture
Fig. 1 Mast cell tryptase suppresses melanoma cell expansion and deliver tryptase into the nucleus of melanoma cells. WT (a) or tryptase-deficient (mMCP6−/−) (b) mouse mast cells were co-cultured with mouse melanoma cells (B16F10) at the ratios indicated, followed by quantification of viable cells using Trypan Blue exclusion. c After co-culture, melanoma cells were separated from mast cells and were analyzed by Western blotting for cell-associated tryptase (mMCP6), CPA3, and core histones H2B, H3, H2A, and H4. Actin was used as loading control. d After co-culture of mast cells and melanoma cells, cells were harvested and analyzed by qPCR for expression of melanoma markers DCT and GP100. The displayed results are from individual experiments, representative of at least three experiments. Data in (a) and (d) are given as mean values ± SEM; *p ≤ 0.05, **p ≤ 0.01, ***p ≤ 0.001. e Confocal microscopy image showing physical contact between mast cells (MC) and melanoma cells (Mel) after co-culture. f, g Controls showing mast cells (f) and melanoma cells (g) alone. h, i Confocal images were analyzed with IMARIS software to generate 3-D-images of the interaction between mast cells and melanoma cells. Note the presence of mast cell tryptase in the nucleus of melanoma cells after mast cell:melanoma cell co-cultureCC BY · PubMed Central
Fig. 2 Human recombinant tryptase affects human melanoma cell phenotype and expansion. Human melanoma cells (MEL526) were incubated for 48 hours with 50 nM human recombinant tryptase. a Microscopy analysis revealing gross morphological alterations in melanoma cell treated with tryptase. b Assessment of cellular size showing that tryptase causes a reduction in melanoma cell size. c, d Quantification of viable cells using Trypan Blue exclusion (c) and CellTiter-Blue® viability probe (d). e Dead cells were quantified using Trypan Blue positivity. Data in (b–e) are given as mean values ± SEM; *p ≤ 0.05, **p ≤ 0.01, ****p ≤ 0.0001
Fig. 2 Human recombinant tryptase affects human melanoma cell phenotype and expansion. Human melanoma cells (MEL526) were incubated for 48 hours with 50 nM human recombinant tryptase. a Microscopy analysis revealing gross morphological alterations in melanoma cell treated with tryptase. b Assessment of cellular size showing that tryptase causes a reduction in melanoma cell size. c, d Quantification of viable cells using Trypan Blue exclusion (c) and CellTiter-Blue® viability probe (d). e Dead cells were quantified using Trypan Blue positivity. Data in (b–e) are given as mean values ± SEM; *p ≤ 0.05, **p ≤ 0.01, ****p ≤ 0.0001CC BY · PubMed Central
Fig. 3 Tryptase causes decreased proliferation of melanoma cells. Melanoma cells (MEL526) were incubated for 48 hours with 50 nM human tryptase. a After incubation, melanoma cells were stained with Annexin V/Draq7 to monitor apoptosis (Annexin V+/Draq7−) and necrosis (Annexin V+/Draq7+). Note that tryptase does not induce apoptosis/necrosis in melanoma cells. b Quantification of the Annexin V/Draq7 staining. c Tryptase-treated melanoma cells (MEL526) were assessed for proliferation through EdU staining. Note the decreased EdU staining after treatment of melanoma cells with tryptase. d–g Quantification of EdU staining of MEL526 (d), MM466 (e), MM253 (f), and A375 (g) melanoma cells. Data in (b, d–g) are given as mean values ± SEM; **p ≤ 0.01, ***p ≤ 0.001; ns, not significant
Fig. 3 Tryptase causes decreased proliferation of melanoma cells. Melanoma cells (MEL526) were incubated for 48 hours with 50 nM human tryptase. a After incubation, melanoma cells were stained with Annexin V/Draq7 to monitor apoptosis (Annexin V+/Draq7−) and necrosis (Annexin V+/Draq7+). Note that tryptase does not induce apoptosis/necrosis in melanoma cells. b Quantification of the Annexin V/Draq7 staining. c Tryptase-treated melanoma cells (MEL526) were assessed for proliferation through EdU staining. Note the decreased EdU staining after treatment of melanoma cells with tryptase. d–g Quantification of EdU staining of MEL526 (d), MM466 (e), MM253 (f), and A375 (g) melanoma cells. Data in (b, d–g) are given as mean values ± SEM; **p ≤ 0.01, ***p ≤ 0.001; ns, not significantCC BY · PubMed Central
Fig. 4 Tryptase is taken up into the nucleus of human melanoma cells, and affects nuclear morphology and histone processing. a Human melanoma cells (MEL526) were incubated with human tryptase at the indicated concentrations, followed by washing of the cells and Western blot analysis for tryptase. Histone 1 (H1) was used as loading control. b Western blot analysis for core histones H2A, H2B, H3, and H4 after incubation of human melanoma cells with tryptase at the indicated concentrations for 48 h. Note the clipping of H3 after treatment of melanoma cells with tryptase. c Confocal analysis showing uptake of tryptase into melanoma cells and blocked uptake in the presence of an endocytosis inhibitor (Dynasore). d 3-D imaging using the IMARIS software showing the presence of tryptase in both the cytoplasm and nucleus of human melanoma cells (see also Supplementary Fig. 2). e DAPI staining of control and tryptase-treated human melanoma cells using super-resolution microscopy analysis. Note the extensive morphological alterations of the nucleus after tryptase treatment. Note also the presence of pores in the nuclear envelope after treatment with tryptase
Fig. 4 Tryptase is taken up into the nucleus of human melanoma cells, and affects nuclear morphology and histone processing. a Human melanoma cells (MEL526) were incubated with human tryptase at the indicated concentrations, followed by washing of the cells and Western blot analysis for tryptase. Histone 1 (H1) was used as loading control. b Western blot analysis for core histones H2A, H2B, H3, and H4 after incubation of human melanoma cells with tryptase at the indicated concentrations for 48 h. Note the clipping of H3 after treatment of melanoma cells with tryptase. c Confocal analysis showing uptake of tryptase into melanoma cells and blocked uptake in the presence of an endocytosis inhibitor (Dynasore). d 3-D imaging using the IMARIS software showing the presence of tryptase in both the cytoplasm and nucleus of human melanoma cells (see also Supplementary Fig. 2). e DAPI staining of control and tryptase-treated human melanoma cells using super-resolution microscopy analysis. Note the extensive morphological alterations of the nucleus after tryptase treatment. Note also the presence of pores in the nuclear envelope after treatment with tryptaseCC BY · PubMed Central
Fig. 5 Tryptase is taken up into human melanoma cells as cargo of melanoma cell-derived exosomes. a Human tryptase was incubated with heparin, cDNA or purified melanoma-derived exosomes as indicated, followed by assessment of enzymatic activity using a chromogenic substrate (S-2288). Note that the symbols representing samples without tryptase (Heparin, cDNA, exosomes) are superimposed and show no detectable activity against S-2288. b Purified melanoma cell-derived exosomes (~4 × 107 exosomes) were either non-treated or digested with DNAse and then incubated with or without tryptase (as indicated), followed by washing and detection of bound tryptase by Western blot analysis. Purified tryptase was included as positive control (left lane). c Purified melanoma cell-derived exosomes (~2.5 × 107 exosomes) were labeled with WGA, incubated with purified tryptase, washed and then incubated with human melanoma cells for 6 h, followed by confocal microscopy analysis. Note the presence of tryptase:WGA double-positive exosomes in the nucleus and cytoplasm of the melanoma cells
Fig. 5 Tryptase is taken up into human melanoma cells as cargo of melanoma cell-derived exosomes. a Human tryptase was incubated with heparin, cDNA or purified melanoma-derived exosomes as indicated, followed by assessment of enzymatic activity using a chromogenic substrate (S-2288). Note that the symbols representing samples without tryptase (Heparin, cDNA, exosomes) are superimposed and show no detectable activity against S-2288. b Purified melanoma cell-derived exosomes (~4 × 107 exosomes) were either non-treated or digested with DNAse and then incubated with or without tryptase (as indicated), followed by washing and detection of bound tryptase by Western blot analysis. Purified tryptase was included as positive control (left lane). c Purified melanoma cell-derived exosomes (~2.5 × 107 exosomes) were labeled with WGA, incubated with purified tryptase, washed and then incubated with human melanoma cells for 6 h, followed by confocal microscopy analysis. Note the presence of tryptase:WGA double-positive exosomes in the nucleus and cytoplasm of the melanoma cellsCC BY · PubMed Central
Fig. 6 Tryptase degrades nuclear hnRNP A2/B1 and Lamin B1 in human melanoma cells. a Nuclear extracts were prepared from human melanoma cells and were incubated with tryptase as indicated, followed by SDS-PAGE analysis and Coomassie staining. The major bands affected by tryptase (arrows) were identified as hnRNP A2/B1 and Lamin B1, respectively. b–d Western blot analysis of hnRNP A2/B1 and Lamin B1 in tryptase-treated nuclear extracts. Quantification of the Lamin B1 and hnRNP A2/B1 bands by densitometric scanning is shown in (c) and (d), respectively. e–g Western blot analysis of hnRNP A2/B1 and Lamin B1 in tryptase-treated cells. Quantification of the Lamin B1 and hnRNP A2/B1 bands by densitometric scanning is shown in (f) and (g), respectively. h Recombinant hnRNP A2/B1 was treated with tryptase, followed by SDS-PAGE and Coomassie staining
Fig. 6 Tryptase degrades nuclear hnRNP A2/B1 and Lamin B1 in human melanoma cells. a Nuclear extracts were prepared from human melanoma cells and were incubated with tryptase as indicated, followed by SDS-PAGE analysis and Coomassie staining. The major bands affected by tryptase (arrows) were identified as hnRNP A2/B1 and Lamin B1, respectively. b–d Western blot analysis of hnRNP A2/B1 and Lamin B1 in tryptase-treated nuclear extracts. Quantification of the Lamin B1 and hnRNP A2/B1 bands by densitometric scanning is shown in (c) and (d), respectively. e–g Western blot analysis of hnRNP A2/B1 and Lamin B1 in tryptase-treated cells. Quantification of the Lamin B1 and hnRNP A2/B1 bands by densitometric scanning is shown in (f) and (g), respectively. h Recombinant hnRNP A2/B1 was treated with tryptase, followed by SDS-PAGE and Coomassie stainingCC BY · PubMed Central
Fig. 7 Tryptase affects the expression of non-coding RNAs and EGR1 in human melanoma cells. Human melanoma cells (MEL526) were incubated with 50 nM tryptase for 48 h, followed by qPCR analysis of the expression of SNORA80E, EGR1, P53, SNORA55, MIR16–2, RNU4–2, SNORA25, and RN7SK as indicated. Data are given as mean values ± SEM; *p ≤ 0.05, **p ≤ 0.01, ****p ≤ 0.0001
Fig. 7 Tryptase affects the expression of non-coding RNAs and EGR1 in human melanoma cells. Human melanoma cells (MEL526) were incubated with 50 nM tryptase for 48 h, followed by qPCR analysis of the expression of SNORA80E, EGR1, P53, SNORA55, MIR16–2, RNU4–2, SNORA25, and RN7SK as indicated. Data are given as mean values ± SEM; *p ≤ 0.05, **p ≤ 0.01, ****p ≤ 0.0001CC BY · PubMed Central

Verification

Claims the paper makes

The claims and statistics of this paper haven’t been checked yet.

Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.

A few free checks a day · papers already verified open instantly · results are public

Claims other papers make about this one

Each is checked against this paper’s own text: does it say what the citing paper says it does?

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

The self-check needs the paper’s full text.

Citations

Cites

Research works printed but not linked: 48

  1. Metcalfe, D. D., Baram, D. & Mekori, Y. A. Mast cells. Physiol. Rev. 77, 1033–1079 (1997). · DOI
  2. Gurish, M. F. & Austen, K. F. Developmental origin and functional specialization of mast cell subsets. Immunity 37, 25–33 (2012). · DOI
  3. Galli, S. J., Nakae, S. & Tsai, M. Mast cells in the development of adaptive immune responses. Nat. Immunol. 6, 135–142 (2005). · DOI
  4. Ribatti, D. & Crivellato, E. The controversial role of mast cells in tumor growth. Int. Rev. Cell Mol. Biol. 275, 89–131 (2009). · DOI
  5. Dalton, D. K. & Noelle, R. J. The roles of mast cells in anticancer immunity. Cancer Immunol. Immunother. 61, 1511–1520 (2012). · DOI
  6. Marichal, T., Tsai, M. & Galli, S. J. Mast cells: potential positive and negative roles in tumor biology. Cancer Immunol. Res. 1, 269–279 (2013). · DOI
  7. Theoharides, T. C. & Conti, P. Mast cells: the JEKYLL and HYDE of tumor growth. Trends Immunol. 25, 235–241 (2004). · DOI
  8. Oldford, S. A. & Marshall, J. S. Mast cells as targets for immunotherapy of solid tumors. Mol. Immunol. 63, 113–124 (2015). · DOI
  9. Rabenhorst, A. et al. Mast cells play a protumorigenic role in primary cutaneous lymphoma. Blood 120, 2042–2054 (2012). · DOI
  10. Soucek, L. et al. Mast cells are required for angiogenesis and macroscopic expansion of Myc-induced pancreatic islet tumors. Nat. Med. 13, 1211–1218 (2007). · DOI
  11. Wernersson, S. & Pejler, G. Mast cell granules: armed for battle. Nat. Rev. Immunol. 14, 478–494 (2014). · DOI · Paper page
  12. Pejler, G., Rönnberg, E., Waern, I. & Wernersson, S. Mast cell proteases: multifaceted regulators of inflammatory disease. Blood 115, 4981–4990 (2010). · DOI
  13. Pejler, G., Åbrink, M., Ringvall, M. & Wernersson, S. Mast cell proteases. Adv. Immunol. 95, 167–255 (2007). · DOI
  14. Galli, S. J. et al. Approaches for analyzing the roles of mast cells and their proteases in vivo. Adv. Immunol. 126, 45–127 (2015). · DOI · Paper page
  15. Grujic, M. et al. The combined action of mast cell chymase, tryptase and carboxypeptidase A3 protects against melanoma colonization of the lung. Oncotarget 8, 25066–25079 (2017). · DOI
  16. Siiskonen, H. et al. Low numbers of tryptase+ and chymase+ mast cells associated with reduced survival and advanced tumor stage in melanoma. Melanoma Res. 25, 479–485 (2015). · DOI
  17. Stieglitz, D. et al. BMP6-induced modulation of the tumor micro-milieu. Oncogene 38, 609–621 (2019). · DOI
  18. Thakurdas, S. M. et al. The mast cell-restricted tryptase mMCP-6 has a critical immunoprotective role in bacterial infections. J. Biol. Chem. 282, 20809–20815 (2007). · DOI
  19. Shin, K. et al. Mouse mast cell tryptase mMCP-6 is a critical link between adaptive and innate immunity in the chronic phase of Trichinella spiralis infection. J. Immunol. 180, 4885–4891 (2008). · DOI
  20. Waern, I. et al. Mast cells limit extracellular levels of IL-13 via a serglycin proteoglycan-serine protease axis. Biol. Chem. 393, 1555–1567 (2012). · DOI
  21. Melo, F. R. et al. Proteolytic histone modification by mast cell tryptase, a serglycin proteoglycan-dependent secretory granule protease. J. Biol. Chem. 289, 7682–7690 (2014). · DOI
  22. Melo, F. R. et al. Tryptase-catalyzed core histone truncation: a novel epigenetic regulatory mechanism in mast cells. J. Allergy Clin. Immunol. 140, 474–485 (2017). · DOI
  23. Akers, I. A. et al. Mast cell tryptase stimulates human lung fibroblast proliferation via protease-activated receptor-2. Am. J. Physiol. Lung Cell Mol. Physiol. 278, L193–L201 (2000). · DOI
  24. Berger, P., Tunon-De-Lara, J. M., Savineau, J. P. & Marthan, R. Selected contribution: tryptase-induced PAR-2-mediated Ca(2+) signaling in human airway smooth muscle cells. J. Appl. Physiol. 91, 995–1003 (2001). · DOI
  25. Corvera, C. U. et al. Mast cell tryptase regulates rat colonic myocytes through proteinase- activated receptor 2. J. Clin. Invest. 100, 1383–1393 (1997). · DOI
  26. Hallgren, J. & Pejler, G. Biology of mast cell tryptase. An inflammatory mediator. FEBS J. 273, 1871–1895 (2006). · DOI
  27. Mori, S. et al. Nafamostat mesilate is an extremely potent inhibitor of human tryptase. J. Pharm. Sci. 92, 420–423 (2003). · DOI
  28. Sharma, P. et al. Immunoaffinity-based isolation of melanoma cell-derived exosomes from plasma of patients with melanoma. J. Extracell. Vesicles 7, 1435138 (2018). · DOI
  29. Meehan, K. & Vella, L. J. The contribution of tumour-derived exosomes to the hallmarks of cancer. Crit. Rev. Clin. Lab Sci. 53, 121–131 (2016). · DOI
  30. Åbrink, M., Grujic, M. & Pejler, G. Serglycin is essential for maturation of mast cell secretory granule. J. Biol. Chem. 279, 40897–40905 (2004). · DOI
  31. Hallgren, J., Karlson, U., Poorafshar, M., Hellman, L. & Pejler, G. Mechanism for activation of mouse mast cell tryptase: dependence on heparin and acidic pH for formation of active tetramers of mouse mast cell protease 6. Biochemistry 39, 13068–13077 (2000). · DOI
  32. Hallgren, J., Spillmann, D. & Pejler, G. Structural requirements and mechanism for heparin-induced activation of a recombinant mouse mast cell tryptase, mouse mast cell protease-6: formation of active tryptase monomers in the presence of low molecular weight heparin. J. Biol. Chem. 276, 42774–42781 (2001). · DOI
  33. Thakur, B. K. et al. Double-stranded DNA in exosomes: a novel biomarker in cancer detection. Cell Res. 24, 766–769 (2014). · DOI
  34. Hanahan, D. & Weinberg, R. A. Hallmarks of cancer: the next generation. Cell 144, 646–674 (2011). · DOI · Paper page
  35. Coussens, L. M., Zitvogel, L. & Palucka, A. K. Neutralizing tumor-promoting chronic inflammation: a magic bullet? Science 339, 286–291 (2013). · DOI
  36. Pereira, P. J. et al. Human beta-tryptase is a ring-like tetramer with active sites facing a central pore. Nature 392, 306–311 (1998). · DOI
  37. Sommerhoff, C. P. et al. The structure of the human betaII-tryptase tetramer: fo(u)r better or worse. Proc. Natl Acad. Sci. USA 96, 10984–10991 (1999). · DOI
  38. Camps, J., Erdos, M. R. & Ried, T. The role of lamin B1 for the maintenance of nuclear structure and function. Nucleus 6, 8–14 (2015). · DOI · Paper page
  39. Jean-Philippe, J., Paz, S. & Caputi, M. hnRNP A1: the Swiss army knife of gene expression. Int. J. Mol. Sci. 14, 18999–19024 (2013). · DOI
  40. Okugawa, Y. et al. Clinical significance of SNORA42 as an oncogene and a prognostic biomarker in colorectal cancer. Gut 66, 107–117 (2017). · DOI
  41. Mei, Y. P. et al. Small nucleolar RNA 42 acts as an oncogene in lung tumorigenesis. Oncogene 31, 2794–2804 (2012). · DOI
  42. Crea, F. et al. Integrated analysis of the prostate cancer small-nucleolar transcriptome reveals SNORA55 as a driver of prostate cancer progression. Mol. Oncol. 10, 693–703 (2016). · DOI
  43. Kuhlmann, J. D. et al. Increased level of circulating U2 small nuclear RNA fragments indicates metastasis in melanoma patients. Clin. Chem. Lab Med. 53, 605–611 (2015). · DOI
  44. Tian, R. et al. Differential expression of miR16 in glioblastoma and glioblastoma stem cells: their correlation with proliferation, differentiation, metastasis and prognosis. Oncogene 36, 5861–5873 (2017). · DOI
  45. Zhao, D. Y., Jacobs, K. M., Hallahan, D. E. & Thotala, D. Silencing Egr1 attenuates radiation-induced apoptosis in normal tissues while killing cancer cells and delaying tumor growth. Mol. Cancer Ther. 14, 2343–2352 (2015). · DOI
  46. Kouzarides, T. Chromatin modifications and their function. Cell 128, 693–705 (2007). · DOI · Paper page
  47. Rönnberg, E. & Pejler, G. Serglycin: the master of the mast cell. Methods Mol. Biol. 836, 201–217 (2012). · DOI
  48. Paivandy, A., Eriksson, J., Melo, F. R., Sellin, M. E. & Pejler, G. Lysosomotropic challenge of mast cells causes intra-granular reactive oxygen species production. Cell Death Discov. 5, 95 (2019). · DOI

Cited by

Sorted by citations

See all 41

Metadata

Authors
Rabelo Melo, F., Santosh Martin, S., Sommerhoff, C. P., & Pejler, G.
Venue
Cell Death & Disease
Publisher
Springer Science and Business Media LLC
Published
2019-09-10
Volume
10
Issue
9
ISSN
2041-4889
DOI
10.1038/s41419-019-1879-4
PMC
PMC6736983
Cited by
41
References
2
Language
en
Licence
Funders
  • Cancerfonden
  • Barncancerfonden
  • Knut och Alice Wallenbergs Stiftelse

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

What counts as a claim ›How we measure confidence ›How we check this ›

Are you an author, or do you see a problem with this page? Request a review