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The chromatin regulator Brg1 suppresses formation of intraductal papillary mucinous neoplasm and pancreatic ductal adenocarcinoma

Abstract

Pancreatic ductal adenocarcinoma (PDA) develops through distinct precursor lesions, including pancreatic intraepithelial neoplasia (PanIN) and intraductal papillary mucinous neoplasia (IPMN). However, genetic features resulting in IPMN-associated PDA (IPMN–PDA) versus PanIN-associated PDA (PanIN-PDA) are largely unknown. Here we find that loss of Brg1, a core subunit of SWI/SNF chromatin remodelling complexes, cooperates with oncogenic Kras to form cystic neoplastic lesions that resemble human IPMN and progress to PDA. Although Brg1-null IPMN–PDA develops rapidly, it possesses a distinct transcriptional profile compared with PanIN-PDA driven by mutant Kras and hemizygous p53 deletion. IPMN–PDA also is less lethal, mirroring prognostic trends in PDA patients. In addition, Brg1 deletion inhibits Kras-dependent PanIN development from adult acinar cells, but promotes Kras-driven preneoplastic transformation in adult duct cells. Therefore, this study implicates Brg1 as a determinant of context-dependent Kras-driven pancreatic tumorigenesis and suggests that chromatin remodelling may underlie the development of distinct PDA subsets.

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Figure 1: Loss of Brg1 leads to reduced pancreas size and duct dilations.
Figure 2: Loss of Brg1 cooperates with Kras to form neoplastic cystic lesions.
Figure 3: Cystic neoplastic lesions resemble human IPMNs but not MCNs.
Figure 4: Molecular characterization of neoplastic cystic lesions.
Figure 5: IPMN lesions progress to form PDA with short latency but carry a much better prognosis for survival than PanIN-PDAs.
Figure 6: IPMN–PDA cells are intrinsically less proliferative than PanIN-PDA cells and carry a distinct molecular profile.
Figure 7: Brg1 ablation abrogates PanIN formation from adult acinar cells.
Figure 8: Brg1 ablation sensitizes adult duct cells to Kras-driven initiation of IPMN-like lesions.

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References

  1. Matthaei, H., Schulick, R. D., Hruban, R. H. & Maitra, A. Cystic precursors to invasive pancreatic cancer. Nat. Rev. Gastroenterol. Hepatol. 8, 141–150 (2011).

    Article  PubMed  PubMed Central  Google Scholar 

  2. Matthaei, H. et al. Clinicopathological characteristics and molecular analyses of multifocal intraductal papillary mucinous neoplasms of the pancreas. Ann. Surg. 255, 326–333 (2012).

    Article  PubMed  Google Scholar 

  3. Poultsides, G. A. et al. Histopathologic basis for the favorable survival after resection of intraductal papillary mucinous neoplasm-associated invasive adenocarcinoma of the pancreas. Ann. Surg. 251, 470–476 (2010).

    Article  PubMed  Google Scholar 

  4. Mino-Kenudson, M. et al. Prognosis of invasive intraductal papillary mucinous neoplasm depends on histological and precursor epithelial subtypes. Gut 60, 1712–1720 (2011).

    Article  PubMed  Google Scholar 

  5. Shi, C. & Hruban, R. H. Intraductal papillary mucinous neoplasm. Hum. Pathol. 43, 1–16 (2012).

    Article  PubMed  Google Scholar 

  6. Ray, K. C. et al. Epithelial tissues have varying degrees of susceptibility to Kras(G12D)-initiated tumorigenesis in a mouse model. PLoS One 6, e16786 (2011).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  7. Visvader, J. E. Cells of origin in cancer. Nature 469, 314–322 (2011).

    Article  CAS  PubMed  Google Scholar 

  8. Habbe, N. et al. Spontaneous induction of murine pancreatic intraepithelial neoplasia (mPanIN) by acinar cell targeting of oncogenic Kras in adult mice. Proc Natl Acad. Sci. USA 105, 18913–18918 (2008).

    Article  PubMed  PubMed Central  Google Scholar 

  9. Kopp, J. L. et al. Identification of Sox9-dependent acinar-to-ductal reprogramming as the principal mechanism for initiation of pancreatic ductal adenocarcinoma. Cancer Cell 22, 737–750 (2012).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  10. Morris, J. P. t., Wang, S. C. & Hebrok, M. KRAS, Hedgehog, Wnt and the twisted developmental biology of pancreatic ductal adenocarcinoma. Nat. Rev. Cancer 10, 683–695 (2010).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  11. von Figura, G., Morris, J. P. t., Wright, C. V. & Hebrok, M. Nr5a2 maintains acinar cell differentiation and constrains oncogenic Kras-mediated pancreatic neoplastic initiation. Gut (2013)10.1136/gutjnl-2012-304287

  12. McKenna, E. S. & Roberts, C. W. Epigenetics and cancer without genomic instability. Cell Cycle 8, 23–26 (2009).

    Article  CAS  PubMed  Google Scholar 

  13. Wilson, B. G. & Roberts, C. W. SWI/SNF nucleosome remodellers and cancer. Nat. Rev. Cancer 11, 481–492 (2011).

    Article  CAS  PubMed  Google Scholar 

  14. Medina, P. P. & Sanchez-Cespedes, M. Involvement of the chromatin-remodelling factor BRG1/SMARCA4 in human cancer. Epigenetics 3, 64–68 (2008).

    Article  PubMed  Google Scholar 

  15. Versteege, I. et al. Truncating mutations of hSNF5/INI1 in aggressive paediatric cancer. Nature 394, 203–206 (1998).

    Article  CAS  PubMed  Google Scholar 

  16. Varela, I. et al. Exome sequencing identifies frequent mutation of the SWI/SNF complex gene PBRM1 in renal carcinoma. Nature 469, 539–542 (2011).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  17. Li, M. et al. Inactivating mutations of the chromatin remodelling gene ARID2 in hepatocellular carcinoma. Nat. Genet. 43, 828–829 (2011).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  18. Gui, Y. et al. Frequent mutations of chromatin remodelling genes in transitional cell carcinoma of the bladder. Nat. Genet. 43, 875–878 (2011).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  19. Wiegand, K. C. et al. ARID1A mutations in endometriosis-associated ovarian carcinomas. N. Engl. J. Med. 363, 1532–1543 (2010).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  20. Biankin, A. V. et al. Pancreatic cancer genomes reveal aberrations in axon guidance pathway genes. Nature 491, 399–405 (2012).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  21. Roberts, C. W., Leroux, M. M., Fleming, M. D. & Orkin, S. H. Highly penetrant, rapid tumorigenesis through conditional inversion of the tumour suppressor gene Snf5. Cancer Cell 2, 415–425 (2002).

    Article  CAS  PubMed  Google Scholar 

  22. Roberts, C. W., Galusha, S. A., McMenamin, M. E., Fletcher, C. D. & Orkin, S. H. Haploinsufficiency of Snf5 (integrase interactor 1) predisposes to malignant rhabdoid tumours in mice. Proc Natl Acad. Sci. USA 97, 13796–13800 (2000).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  23. Glaros, S., Cirrincione, G. M., Palanca, A., Metzger, D. & Reisman, D. Targeted knockout of BRG1 potentiates lung cancer development. Cancer Res. 68, 3689–3696 (2008).

    Article  CAS  PubMed  Google Scholar 

  24. Jones, S. et al. Core signalling pathways in human pancreatic cancers revealed by global genomic analyses. Science 321, 1801–1806 (2008).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  25. Shain, A. H. et al. Convergent structural alterations define SWItch/Sucrose NonFermentable (SWI/SNF) chromatin remodeler as a central tumour suppressive complex in pancreatic cancer. Proc Natl Acad. Sci. USA 109E, 252–259 (2012).

    Article  Google Scholar 

  26. Dal Molin, M. et al. Loss of expression of the SWI/SNF chromatin remodelling subunit BRG1/SMARCA4 is frequently observed in intraductal papillary mucinous neoplasms of the pancreas. Hum. Pathol. 43, 585–591 (2012).

    Article  CAS  PubMed  Google Scholar 

  27. Sumi-Ichinose, C., Ichinose, H., Metzger, D. & Chambon, P. SNF2β-BRG1 is essential for the viability of F9 murine embryonal carcinoma cells. Mol. Cell Biol. 17, 5976–5986 (1997).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  28. Kawaguchi, Y. et al. The role of the transcriptional regulator Ptf1a in converting intestinal to pancreatic progenitors. Nat. Genet. 32, 128–134 (2002).

    Article  CAS  PubMed  Google Scholar 

  29. Heiser, P. W., Lau, J., Taketo, M. M., Herrera, P. L. & Hebrok, M. Stabilization of β-catenin impacts pancreas growth. Development 133, 2023–2032 (2006).

    Article  CAS  PubMed  Google Scholar 

  30. Bardeesy, N. et al. Both p16(Ink4a) and the p19(Arf)-p53 pathway constrain progression of pancreatic adenocarcinoma in the mouse. Proc Natl Acad. Sci. USA 103, 5947–5952 (2006).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  31. Hingorani, S. R. et al. Preinvasive and invasive ductal pancreatic cancer and its early detection in the mouse. Cancer Cell 4, 437–450 (2003).

    Article  CAS  PubMed  Google Scholar 

  32. Izeradjene, K. et al. Kras(G12D) and Smad4/Dpc4 haploinsufficiency cooperate to induce mucinous cystic neoplasms and invasive adenocarcinoma of the pancreas. Cancer Cell 11, 229–243 (2007).

    Article  CAS  PubMed  Google Scholar 

  33. Siveke, J. T. et al. Concomitant pancreatic activation of Kras(G12D) and Tgfa results in cystic papillary neoplasms reminiscent of human IPMN. Cancer Cell 12, 266–279 (2007).

    Article  CAS  PubMed  Google Scholar 

  34. Morris, J. P. t., Cano, D. A., Sekine, S., Wang, S. C. & Hebrok, M. β-catenin blocks Kras-dependent reprogramming of acini into pancreatic cancer precursor lesions in mice. J. Clin. Invest. 120, 508–520 (2010).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  35. Tanaka, T. et al. Evaluation of SOX9 expression in pancreatic ductal adenocarcinoma and intraductal papillary mucinous neoplasm. Pancreas 42, 488–493 (2012).

    Article  CAS  Google Scholar 

  36. Fukuda, A. et al. Stat3 and MMP7 contribute to pancreatic ductal adenocarcinoma initiation and progression. Cancer Cell 19, 441–455 (2011).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  37. Lesina, M. et al. Stat3/Socs3 activation by IL-6 transsignalling promotes progression of pancreatic intraepithelial neoplasia and development of pancreatic cancer. Cancer Cell 19, 456–469 (2011).

    Article  CAS  PubMed  Google Scholar 

  38. Corcoran, R. B. et al. STAT3 plays a critical role in KRAS-induced pancreatic tumorigenesis. Cancer Res. 71, 5020–5029 (2011).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  39. Aguirre, A. J. et al. Activated Kras and Ink4a/Arf deficiency cooperate to produce metastatic pancreatic ductal adenocarcinoma. Genes Dev. 17, 3112–3126 (2003).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  40. Morton, J. P. et al. LKB1 haploinsufficiency cooperates with Kras to promote pancreatic cancer through suppression of p21-dependent growth arrest. Gastroenterology 139, 586–597 (2010).

    Article  CAS  PubMed  Google Scholar 

  41. Takehara, A. et al. Gamma-aminobutyric acid (GABA) stimulates pancreatic cancer growth through overexpressing GABAA receptor pi subunit. Cancer Res. 67, 9704–9712 (2007).

    Article  CAS  PubMed  Google Scholar 

  42. Fusco, A. & Fedele, M. Roles of HMGA proteins in cancer. Nat. Rev. Cancer 7, 899–910 (2007).

    Article  CAS  PubMed  Google Scholar 

  43. Winslow, M. M. et al. Suppression of lung adenocarcinoma progression by Nkx2-1. Nature 473, 101–104 (2011).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  44. Piscuoglio, S. et al. HMGA1 and HMGA2 protein expression correlates with advanced tumour grade and lymph node metastasis in pancreatic adenocarcinoma. Histopathology 60, 397–404 (2012).

    Article  PubMed  Google Scholar 

  45. Dozynkiewicz, M. A. et al. Rab25 and CLIC3 collaborate to promote integrin recycling from late endosomes/lysosomes and drive cancer progression. Dev. Cell 22, 131–145 (2012).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  46. Masui, T. et al. Expression of METH-1 and METH-2 in pancreatic cancer. Clin Cancer Res. 7, 3437–3443 (2001).

    CAS  PubMed  Google Scholar 

  47. Wu, J. et al. Recurrent GNAS mutations define an unexpected pathway for pancreatic cyst development. Sci. Trans. Med. 3, 92ra66 (2011).

    Article  CAS  Google Scholar 

  48. Wu, J. et al. Whole-exome sequencing of neoplastic cysts of the pancreas reveals recurrent mutations in components of ubiquitin-dependent pathways. Proc. Nat. Acad. Sci. USA 108, 21188–21193 (2011).

    Article  PubMed  PubMed Central  Google Scholar 

  49. Furukawa, T. et al. Whole-exome sequencing uncovers frequent GNAS mutations in intraductal papillary mucinous neoplasms of the pancreas. Sci. Rep. 1, 161 (2011).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  50. Kanda, M. et al. Mutant GNAS detected in duodenal collections of secretin-stimulated pancreatic juice indicates the presence or emergence of pancreatic cysts. Gut 62, 1024–1033 (2013).

    Article  CAS  PubMed  Google Scholar 

  51. Pan, F. C. et al. Spatiotemporal patterns of multipotentiality in Ptf1a-expressing cells during pancreas organogenesis and injury-induced facultative restoration. Development 140, 751–764 (2013).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  52. Solar, M. et al. Pancreatic exocrine duct cells give rise to insulin-producing β cells during embryogenesis but not after birth. Dev. Cell 17, 849–860 (2009).

    Article  CAS  PubMed  Google Scholar 

  53. Wang, X. et al. Expression of p270 (ARID1A), a component of human SWI/SNF complexes, in human tumours. Int. J. Cancer 112, 636–642 (2004).

    Article  CAS  PubMed  Google Scholar 

  54. Kang, H., Cui, K. & Zhao, K. BRG1 controls the activity of the retinoblastoma protein via regulation of p21CIP1/WAF1/SDI. Mol. Cell Biol. 24, 1188–1199 (2004).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  55. Guan, B., Wang, T. L. & Shih Ie, M. ARID1A, a factor that promotes formation of SWI/SNF-mediated chromatin remodelling, is a tumour suppressor in gynecologic cancers. Cancer Res. 71, 6718–6727 (2011).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  56. Hendricks, K. B., Shanahan, F. & Lees, E. Role for BRG1 in cell cycle control and tumour suppression. Mol. Cell Biol. 24, 362–376 (2004).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  57. Kia, S. K., Gorski, M. M., Giannakopoulos, S. & Verrijzer, C. P. SWI/SNF mediates polycomb eviction and epigenetic reprogramming of the INK4b-ARF-INK4a locus. Mol. Cell Biol. 28, 3457–3464 (2008).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  58. Bourgo, R. J. et al. SWI/SNF deficiency results in aberrant chromatin organization, mitotic failure, and diminished proliferative capacity. Mol. Biol. Cell 20, 3192–3199 (2009).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  59. Trapnell, C., Pachter, L. & Salzberg, S. L. TopHat: discovering splice junctions with RNA-Seq. Bioinformatics 25, 1105–1111 (2009).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  60. Kent, W. J. et al. The human genome browser at UCSC. Genome Res. 12, 996–1006 (2002).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  61. Li, H. et al. The sequence alignment/map format and SAMtools. Bioinformatics 25, 2078–2079 (2009).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

Download references

Acknowledgements

We thank C. Wright for sharing Ptf1a–Cre and Ptf1a–CreER mice, D. Tuveson for KrasG12D mice, and P. Chambon and D. Reisman for Brg1flox mice, respectively. We thank C. Austin and D. Ngow for tissue processing and excellent technical assistance and all M.H. laboratory members for helpful discussion. Work in M.H.’s laboratory was supported by a grant from the NIH (CA112537). G.v.F. was supported by a post-doctoral Research Fellowship from the Deutsche Forschungsgemeinschaft (DFG, FI 1719/1-1) and a Klein Family Foundation Fellowship. A.F. was supported by a post-doctoral Research Fellowship from the Japan Society for the Promotion of Science, a Fellowship from the US National Pancreas Foundation, and a Fellowship from the Kato Memorial Biosciences Foundation. M.E.L. was supported by CIRM training grant TG2 01153. W.F.M., A.B. and K.J.H. were supported by a grant from the NIH (CA149548). Image acquisition was supported by the imaging core of the UCSF Diabetes and Endocrinology Research Center (DERC) NIH grant P30DK63720.

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Contributions

G.V.F., A.F., N.R. and M.E.L. contributed to equal parts. G.V.F., A.F., N.R. and M.E.L. carried out all experiments and were involved together with M.H. in design and analysis of the experiments. G.V.F., A.F., N.R., M.E.L. and M.H. drafted the manuscript. J.P.M.I.V. generated cell lines, contributed to the survival analysis, was involved in experimental analysis, and critically reviewed the manuscript. G.E.K. performed the histopathological analysis including IPMN and tumour identification and tumour grading. H.R. performed quantification of tumour proliferation. J.F. generated the HNF1b–CreERT2 mice. D.W.D. analysed Brg1 expression on human samples. M.A.F., S.J.M. and J.F. provided intellectual contribution to this study. M.F.W., A.B. and K.J.H. carried out deep sequencing analyses. M.H. conceived the study.

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Correspondence to Matthias Hebrok.

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The authors declare no competing financial interests.

Integrated supplementary information

Supplementary Figure 1 Cystic lesions in Ptf1a-Cre; KrasG12D; Brg1f/f pancreata are marked by thin stroma and are reminiscent of human pancreatobiliary IPMN.

(a) Representative H&E staining of a cystic lesion in Ptf1a-Cre; KrasG12D; Brg1f/f pancreata reveals thin underlying stroma (S = stroma, E = epithelium). Despite some variability the majority of cystic lesions in Ptf1a-Cre; KrasG12D; Brg1f/f mice presented with thin stroma lacking cells with wavy nuclei. (b) H&E staining of representative fibrovascular bundle in Ptf1a-Cre; KrasG12D; Brg1f/f pancreata. (c) Cystic lesions of Ptf1a-Cre; KrasG12D; Brg1f/f and PanINs of Ptf1a-Cre; KrasG12D mice stain positive for Muc5AC (a’e’), and Muc1 (a”’e”’), but are negative for Muc2 (a”e”). In contrast, ducts of control mice do not express Muc5AC and Muc2 (a’, a”, a”’). The mucin expression pattern of the cystic lesions in Ptf1a-Cre; KrasG12D; Brg1f/f pancreata (positivity for Muc1, and Muc5AC and negativity for Muc2) matches that of human IPMNs of the pancreatobiliary type (e’, e”, e”’). (a) and (c) scale bar 50 μm, (b) scale bar 100 μm.

Supplementary Figure 2 Brg1 is lost in neoplastic epithelium of Ptf1a-Cre; KrasG12D; Brg1f/f mice and characterization of Brg1 null PDA cell lines.

(a) (a’) Immunohistochemistry staining for Brg1 on neoplastic epithelium of a 9 weeks old Ptf1a-Cre; KrasG12D; Brg1f/f mouse. Low grade dysplasia marked by the presence of abundant mucin, undulating base, nuclear enlargement, or papillary or very dilated structures, tended to be negative for Brg1. In contrast, intermediate to high-grade dysplasia was uniformly negative for Brg1. (b’) Higher magnification of a low-grade dysplastic epithelium. (c’) Higher magnification of an intermediate to high-grade dysplastic epithelium. Scale bar 250 μm. (b) (a”) PCR analysis of the KrasG12D (Kras PCR: 1–4) and Brg1f/f (Brg1 PCR: 5–9) alleles in cancer cell lines. Murine genomic DNA was isolated from the following sources 1: Kras+/+ (embryonic fibroblasts isolated from a wild type mouse). 2: unrecombined KrasG12D/+ (embryonic fibroblasts isolated from a KrasG12D/+ mouse). 3: Ptf1a-Cre; KrasG12D; p53f/+ cancer cell line. 4: Ptf1a-Cre; KrasG12D; Brg1f/f cancer cell line. 5: Brg1+/+ (tail of a wild type mouse). 6: unrecombined Brg1f/+ (tail of Brg1f/+ mouse). 7: unrecombined Brg1f/f (tail of Brg1f/f mouse). 8: Ptf1a-Cre; KrasG12D; p53f/+ cancer cell line. 9: Ptf1a-Cre; KrasG12D; Brg1f/f cancer cell line. wt = wt allele, flox = unrecombined floxed allele, rec = recombined floxed allele. (b”) Western blot analysis of Brg1 in cancer cell lines derived from IPMN- and PanIN-PDAs. (c) Anoikis analysis of PanIN-PDA (n = 3), IPMN–PDA (n = 3 independent experiments) and Ptf1a-Cre; KrasG12D (n = 3 independent experiments) derived cancer cells by Annexin V/PI staining. 200,000 Cells were seeded onto poly-hema coated petri dishes to inhibit cell adhesion. After 48 h, detachment induced cell death or anoikis was assayed by measuring both early and late apoptosis. Total apoptosis is measured by counting both Annexin V single positive cells (early apoptotic) and Annexin V/PI double positive cells are (late apoptotic). Values are shown mean + /− SD. p value for total apoptosis was calculated by one way ANOVA between three sets of cell lines.

Supplementary Figure 3 Tumour suppressor gene expression in PDA and PDA precursor lesions.

(a) Immunohistochemistry staining for p53, p21, and p16 on pancreatic tissue isolated from PanIN-PDA and IPMN–PDA in mice. Scale bars 50 μm. (b) Immunohistochemistry for p53, p21, and p16 in ADM/PanIN and IPMN neoplastic precursor lesions on pancreatic sections derived from Ptf1a-Cre; KrasG12D and Ptf1a-Cre; KrasG12D; Brg1f/f mice. Insets show higher magnification pictures of PanIN or IPMN lesions. Scale bars 50 μm. (c) Quantification of p16 positive PDA cells in PanIN- versus IPMN–PDA (n = 7 tumours; values are shown as mean ± s.e.m. unpaired t-test was used for calculating p values). (d) Summary of tumour suppressor gene expression in cancer and precursor lesions of the respective genotypes. (e) Real-time PCR (RT-PCR) for Hmga2 relative to Cyclophilin A in murine pancreas containing PanIN (from Ptf1a-Cre; KrasG12D mice;n = 3) or IPMN (from Ptf1a-Cre; KrasG12D; Brg1f/f mice;n = 3) lesions. Values are shown mean ± s.e.m. Unpaired t-test was performed to calculate the p value.

Supplementary Figure 4 Brg1 null PDA cells display a gene pathway signature indicative of lower malignant potential.

Gene pathway/function analysis displaying the deep sequencing results of PanIN-PDA versus Brg1 null IPMN–PDA using Ingenuity®; software. The analysis was performed by focusing on those genes with significantly altered expression levels (p < 0.05) between PanIN- and IPMN–PDA. (a) Depicted is the heatmap clustering of the affected genes grouped into categories of cellular function. Highlighted in green are gene signatures with a z-score <= −2. The z-score reflects the significance and direction of the deviation of the individual gene signature from the mean. Category 1 = Cellular Movement, 2 = Hematological System Development and function, 3 = Cell to cell signalling and interaction, 4 = Tissue Development, 5 = Immune Cell Trafficking, 6 = Cancer, 7 = Cardiovascular system development and function, 8 = Inflammatory response, 9 = Cellular growth and proliferation, 10 = Cellular development, 11 = Organismal injury and abnormalities, 12 = Tissue morphology, 13 = Skeletal and muscular system development and function, 14 = Gastrointestinal diseases, 15 = Antigen presentation, 16 = Hepatic system disease, 17 = Infectious disease. (b) List of the 15 most significantly down-regulated pathways in IPMN–PDA.

Supplementary Figure 5 Sequence alignment of promoter regions.

Sequence alignment of promoter regions from mouse and human. Peak heights indicate degree of homology. Pink horizontal lines indicate evolutionary conserved regions. +1 indicates the start site. Black boxes are regions analyzed by ChIP. Blue: Coding exons, Yellow: Untranslated region, Red: Promoter elements, Salmon: Intronic region.

Supplementary Figure 6 ChIP analysis of promoter regions in PanIN- and IPMN–PDA cells.

(a) Relative fold enrichment of H3K4Me3 and H3K27Me3 (over IgG control) on promoter regions in PanIN-PDA cells (1 × 106 cells/ ., n = 3 independent experiments). Decreases in the solid color bars (H3K27) indicate a relative increase in active chromatin marks. Increases in the solid bars point to a relative increase in repressive marks. Each panel indicates individual cell lines. Values are shown as mean ± s.e.m. (b) Relative fold enrichment of H3K4Me3 and H3K27Me3 (over IgG control) on promoter regions in IPMN–PDA cells (1 × 106 cells/ ChIP; n = 3 independent experiments). Decreases in the solid color bars (H3K27) indicate a relative increase in active chromatin marks. Increases in the solid bars point to a relative increase in repressive marks. Each panel indicates individual cell lines. Values are shown as mean ± s.e.m.

Supplementary Figure 7 Brg1 ablation abrogates PanIN formation from adult acinar cells and does not induce duct cell atypia in the absence of oncogenic Kras.

(a) H&E and Alcian blue stainings of pancreata derived from Ptf1a-CreER; Kras, Ptf1a-CreER; Kras; Brg1f/+ (= Brg1 het) and Ptf1a-CreER; Kras; Brg1f/f (= Brg1 KO) mice 4 months after tamoxifen induction. Note the strong reduction of Alcian blue PanIN lesions in Ptf1a-CreER; Kras; Brg1f/f (= Brg1 KO) mice. (b) A representative image of a pancreatic duct of an Hnf1b-CreERT2; Brg1f/f; R26REYFP mouse 6 weeks after tamoxifen induction. A total of, 3 Hnf1b-CreERT2; Brg1f/f (± R26REYFP) mice were analyzed 6 weeks (n = 1) or 12 weeks (n = 2) after tamoxifen induction. None of the mice showed duct cell atypia on histological examination (c) YFP staining confirmed recombination upon tamoxifen administration in both the large (arrow) and small (asterisks) duct system. (a) and (b) Scale bar 100 μm, (c) scale bar 50 μm.

Supplementary Figure 8 Brg1 expression is associated with progression of human PanIN- and IPMN–PDA.

(a) Kaplan-Meier survival curve of PanIN-PDA patients with low or high Brg1 expression in tumour cells (n = 36 for low Brg1 and n = 106 for high Brg1). Brg1 expression was scored using a histoscore ranging from 0–8 (low to high expression). The cut off histoscore was 0–6 for low and 7–8 for high Brg1 expression. Log rank test, p = 0.007. Median survival was for low BRG1 = 15.1 months (95% CI 12.3-18.0) and for high BRG1 = 28.1 months (95% CI 24.3–31.8). (b) Brg1 labeling score from matched patient samples with IPMN and associated IPMN–PDA. The Brg1 expression was scored on the same section of a patient sample that contained an IPMN precursor and its associated IPMN–PDA. p value was calculated using the paired t-test; n=11 samples for IPMN precursors and n = 12 samples for IPMN–PDA, values are shown as mean ± s.e.m.

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von Figura, G., Fukuda, A., Roy, N. et al. The chromatin regulator Brg1 suppresses formation of intraductal papillary mucinous neoplasm and pancreatic ductal adenocarcinoma. Nat Cell Biol 16, 255–267 (2014). https://doi.org/10.1038/ncb2916

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