Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

Acinar cell clonal expansion in pancreas homeostasis and carcinogenesis


Pancreatic ductal adenocarcinoma (PDAC) is one of the leading causes of cancer deaths worldwide1. Studies in human tissues and in mouse models have suggested that for many cancers, stem cells sustain early mutations driving tumour development2,3. For the pancreas, however, mechanisms underlying cellular renewal and initiation of PDAC remain unresolved. Here, using lineage tracing from the endogenous telomerase reverse transcriptase (Tert) locus, we identify a rare TERT-positive subpopulation of pancreatic acinar cells dispersed throughout the exocrine compartment. During homeostasis, these TERThigh acinar cells renew the pancreas by forming expanding clones of acinar cells, whereas randomly marked acinar cells do not form these clones. Specific expression of mutant Kras in TERThigh acinar cells accelerates acinar clone formation and causes transdifferentiation to ductal pre-invasive pancreatic intraepithelial neoplasms by upregulating Ras–MAPK signalling and activating the downstream kinase ERK (phospho-ERK). In resected human pancreatic neoplasms, we find that foci of phospho-ERK-positive acinar cells are common and frequently contain activating KRAS mutations, suggesting that these acinar regions represent an early cancer precursor lesion. These data support a model in which rare TERThigh acinar cells may sustain KRAS mutations, driving acinar cell expansion and creating a field of aberrant cells initiating pancreatic tumorigenesis.

This is a preview of subscription content, access via your institution

Relevant articles

Open Access articles citing this article.

Access options

Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.

Fig. 1: Identification of an acinar cell subpopulation with elevated Tert expression.
Fig. 2: TERThigh acinar cells repopulate the pancreas during homeostasis and regeneration.
Fig. 3: TERThigh acinar cells initiate pancreatic neoplasia upon Kras activation and injury.
Fig. 4: Identification of pERK+ human acinar cells harbouring KRAS mutations.

Data availability

Sequencing data for KRAS variants is available with the SRA accession: PRJNA598774. All other data are available from the authors upon reasonable request. Source data are provided with this paper.

Code availability

Custom Python scripts used in this manuscript are available at (


  1. Rawla, P., Sunkara, T. & Gaduputi, V. Epidemiology of pancreatic cancer: global trends, etiology and risk factors. World J. Oncol. 10, 10–27 (2019).

    Article  Google Scholar 

  2. Jan, M. et al. Clonal evolution of preleukemic hematopoietic stem cells precedes human acute myeloid leukemia. Sci. Transl. Med. 4, 149ra118 (2012).

    Article  Google Scholar 

  3. Barker, N. et al. Crypt stem cells as the cells-of-origin of intestinal cancer. Nature 457, 608–611 (2009).

    Article  ADS  CAS  Google Scholar 

  4. Murtaugh, L. C. & Keefe, M. D. Regeneration and repair of the exocrine pancreas. Annu. Rev. Physiol. 77, 229–249 (2015).

    Article  CAS  Google Scholar 

  5. Desai, B. M. et al. Preexisting pancreatic acinar cells contribute to acinar cell, but not islet β cell, regeneration. J. Clin. Invest. 117, 971–977 (2007).

    Article  CAS  Google Scholar 

  6. Westphalen, C. B. et al. Dclk1 defines quiescent pancreatic progenitors that promote injury-induced regeneration and tumorigenesis. Cell Stem Cell 18, 441–455 (2016).

    Article  CAS  Google Scholar 

  7. Sangiorgi, E. & Capecchi, M. R. Bmi1 lineage tracing identifies a self-renewing pancreatic acinar cell subpopulation capable of maintaining pancreatic organ homeostasis. Proc. Natl Acad. Sci. USA 106, 7101–7106 (2009).

    Article  ADS  CAS  Google Scholar 

  8. Hruban, R. H., Goggins, M., Parsons, J. & Kern, S. E. Progression model for pancreatic cancer. Clin. Cancer Res. 6, 2969–2972 (2000).

    CAS  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  Google Scholar 

  10. 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  ADS  CAS  Google Scholar 

  11. De La, O. J. et al. Notch and Kras reprogram pancreatic acinar cells to ductal intraepithelial neoplasia. Proc. Natl Acad. Sci. USA 105, 18907–18912 (2008).

    Article  ADS  Google Scholar 

  12. Flowers, B. M. et al. Cell of origin influences pancreatic cancer subtype. Cancer Discov. 11, 660–677 (2021).

    Article  CAS  Google Scholar 

  13. Boj, S. F. et al. Organoid models of human and mouse ductal pancreatic cancer. Cell 160, 324–338 (2015).

    Article  CAS  Google Scholar 

  14. Lee, J. et al. Reconstituting development of pancreatic intraepithelial neoplasia from primary human pancreas duct cells. Nat. Commun. 8, 14686 (2017).

    Article  ADS  Google Scholar 

  15. Kanda, M. et al. Presence of somatic mutations in most early-stage pancreatic intraepithelial neoplasia. Gastroenterology 142, 730–733.e739 (2012).

    Article  CAS  Google Scholar 

  16. Shi, C. et al. KRAS2 mutations in human pancreatic acinar-ductal metaplastic lesions are limited to those with PanIN: implications for the human pancreatic cancer cell of origin. Mol. Cancer Res. 7, 230–236 (2009).

    Article  CAS  Google Scholar 

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

    Article  ADS  CAS  Google Scholar 

  18. 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  Google Scholar 

  19. Ying, H. et al. Genetics and biology of pancreatic ductal adenocarcinoma. Genes Dev. 30, 355–385 (2016).

    Article  CAS  Google Scholar 

  20. Roake, C. M. & Artandi, S. E. Regulation of human telomerase in homeostasis and disease. Nat. Rev. Mol. Cell Biol. 21, 384–397 (2020).

    Article  CAS  Google Scholar 

  21. Pech, M. F. et al. High telomerase is a hallmark of undifferentiated spermatogonia and is required for maintenance of male germline stem cells. Genes Dev. 29, 2420–2434 (2015).

    Article  CAS  Google Scholar 

  22. Petersen, G. M. et al. A genome-wide association study identifies pancreatic cancer susceptibility loci on chromosomes 13q22.1, 1q32.1 and 5p15.33. Nat. Genet. 42, 224–228 (2010).

    Article  CAS  Google Scholar 

  23. Lin, S. et al. Distributed hepatocytes expressing telomerase repopulate the liver in homeostasis and injury. Nature 556, 244–248 (2018).

    Article  ADS  CAS  Google Scholar 

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

    Article  CAS  Google Scholar 

  25. Pylayeva-Gupta, Y., Grabocka, E. & Bar-Sagi, D. RAS oncogenes: weaving a tumorigenic web. Nat. Rev. Cancer 11, 761–774 (2011).

    Article  CAS  Google Scholar 

  26. Collins, M. A., Yan, W., Sebolt-Leopold, J. S. & Pasca di Magliano, M. MAPK signaling is required for dedifferentiation of acinar cells and development of pancreatic intraepithelial neoplasia in mice. Gastroenterology 146, 822–834.e827 (2014).

    Article  CAS  Google Scholar 

  27. Bryant, K. L., Mancias, J. D., Kimmelman, A. C. & Der, C. J. KRAS: feeding pancreatic cancer proliferation. Trends Biochem. Sci 39, 91–100 (2014).

    Article  CAS  Google Scholar 

  28. Martincorena, I. et al. Somatic mutant clones colonize the human esophagus with age. Science 362, 911–917 (2018).

    Article  ADS  CAS  Google Scholar 

  29. Martincorena, I. et al. Tumor evolution. High burden and pervasive positive selection of somatic mutations in normal human skin. Science 348, 880–886 (2015).

    Article  ADS  CAS  Google Scholar 

  30. Busque, L. et al. Recurrent somatic TET2 mutations in normal elderly individuals with clonal hematopoiesis. Nat. Genet. 44, 1179–1181 (2012).

    Article  CAS  Google Scholar 

  31. Madisen, L. et al. A robust and high-throughput Cre reporting and characterization system for the whole mouse brain. Nat. Neurosci. 13, 133–140 (2010).

    Article  CAS  Google Scholar 

  32. Jackson, E. L. et al. Analysis of lung tumor initiation and progression using conditional expression of oncogenic K-ras. Genes Dev. 15, 3243–3248 (2001).

    Article  CAS  Google Scholar 

  33. Kopinke, D. et al. Ongoing Notch signaling maintains phenotypic fidelity in the adult exocrine pancreas. Dev. Biol. 362, 57–64 (2012).

    Article  CAS  Google Scholar 

  34. Hegyi, P. et al. l-arginine-induced experimental pancreatitis. World J. Gastroenterol. 10, 2003–2009 (2004).

    Article  CAS  Google Scholar 

Download references


This work was supported by grants from the NIH (AG056575, CA244114 and CA197563; S.E.A.), the Emerson Collective (S.E.A.), anonymous support (S.E.A.), the DFG (NE 2006/1-1; P.N.), California TRDRP (25FT-0011; P.N.) and the California Institute for Regenerative Medicine (R.J.L.). We thank members of the Artandi laboratory for critical comments and P. Chu from the Stanford Human Pathology/Histology Service Center for technical assistance, and acknowledge the Stanford Functional Genomics Facility and Stanford Shared FACS Facility.

Author information

Authors and Affiliations



P.N. and S.E.A. conceived the study. P.N. and S.E.A. designed the experiments. P.N., S.J.K. and R.J.L. performed histological analysis. P.N. and R.B.W. performed the LCM experiments. G.W.C. analysed and evaluated the human patient samples. C.M.R. performed the sequencing analyses. P.N. and S.E.A. analysed the data and wrote the paper.

Corresponding author

Correspondence to Steven E. Artandi.

Ethics declarations

Competing interests

The authors declare no competing interests.

Additional information

Peer review information Nature thanks Laura Wood and the other, anonymous, reviewer(s) for their contribution to the peer review of this work. Peer reviewer reports are available.

Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Extended data figures and tables

Extended Data Fig. 1 Identification of a TERT-high subpopulation in acinar cells and beta cells but not duct cells using lineage tracing.

a, TertCreERT2/+; Rosa26LSL-tdTomato/+ mouse, which responds to tamoxifen-induced Cre-mediated activation of the tdTomato reporter allele. b, Immunohistochemistry analysis of Tomato in a TertCreERT2/+; Rosa26LSL-tdTomato/+ (TertCreER) pancreas after oil and tamoxifen injection (n=4 mice for oil ctrl; n=11 mice for tamoxifen). Mo, month. c, d, Co-immunofluorescence stains 10 days after single dose of tamoxifen (5mg) in TertCreER pancreas (n=4 mice). Tomato (red, c, d), DAPI (blue, c, d), Insulin (grey, c, d) Sox9 (green, c) and Amylase (green, d) are shown. e, f, Single-molecule RNA FISH for Tert mRNA (e) on FACS-purified bulk acinar cells (e, f) from TertCreER mice 10d after Tamoxifen (5mg) injection (n=4 mice). g, Quantification of Tomato-positive cells in TertCreER mice in the acinar cell compartment 10 days and within pancreatic ductal cells 10 days and 12 months post tamoxifen activation (n=5 mice). h, qRT-PCR for indicated genes in FACS-sorted TomNeg (white bars) and TomPos (grey bars) acinar cells. i, j, Immunofluorescence analysis of a TertCreER pancreas 10 days after a single dose of 5mg tamoxifen (n=5 mice). Tomato (red), Dclk1 (i, green) or BMI1 (j, green) and DAPI (blue) are shown. Scale bar, 100µm (b), 50µm (e, f) and 25µm (c, d, i, j). All data are mean± SD. P values calculated by two-sided Mann-Whitney test (h).

Source data

Extended Data Fig. 2 Randomly marked acinar cells show limited clonogenicity and TERT-high acinar cells renew to yield TERT-low cells.

a, Schematic of lineage tracing in TertCreER mice treated with a single dose of tamoxifen on postnatal day 60 and analysis at indicated time points. Mo, month. bd, Immunohistochemistry for Tomato in Ptf1aCreER mice 10d post tamoxifen (5mg (b), 0.5mg (c) and 0.05mg (d)) injection (n=4 mice). e, Distribution of Tomato-positive acinar cells per clone for each time point in Ptf1aCreER mice (each color represents one mouse; n=4 for each time point) f, TertCreER mice are injected with Tamoxifen (5mg) on postnatal day 60 and put on BrdU water (1mg/ml) for 30 days. g, Immunofluorescence analysis of a TertCreER pancreas after 30 days of BrdU water. Tomato (red), BrdU (green) and DAPI (blue) are shown. TERTHigh Tomato/BrdU double positive cells (green arrow) and TERTLow BrdU positive cells (orange arrow) shown. h, Quantification of TERTLow and TERTHigh BrdU+ cells (n=5 mice) (mean ± SD). ik, Single-molecule RNA FISH for Tert on FACS-purified bulk (i), TERTHigh (j) and TERTLow derived (k) acinar cells of TertCreER mice(n=3). Scale bars, 25µm (g), 50µm (ik), 100 µm (bd). P values calculated by two-sided Mann-Whitney test (h).

Source data

Extended Data Fig. 3 During injury, TERTHigh acinar show enhanced repopulation compared with randomly marked acinar cells.

a, Schema of cerulein-induced pancreatitis. b, Immunofluorescence analysis of TertCreER mice 30 days after cerulein injections. Tomato (red), Ki67 (green) and DAPI (blue) are shown. TERTHigh, Ki67+ positive cells (green arrow) and TERTLow, Ki67+ cells (orange arrows) are shown. c, Quantification of TERTHigh, Ki67+ and TERTLow, Ki67+ cells at indicated time points (n=5 mice) (mean ± SD). d, Schematic of L-Arginine induced pancreatitis. e, Immunofluorescence analysis of TertCreER mice 30 days after L-Arginine induced pancreatitis. f, Quantification of Tomato-positive cells per clone with and without injury (n=5 mice) (mean ± SD). Scale bars, 25µm (d), 250 µm (e). P values calculated by two-sided Mann-Whitney test (c, f).

Source data

Extended Data Fig. 4 Enhanced PanIN formation from TERT-High acinar cells compared with sparsely labeled randomly marked acinar cells.

a, Schema for cerulein-induced pancreatitis. b, Immunohistochemistry for Tomato in Ptf1aCreER; Kras mice and TertCreER; Kras mice one month after cerulein-induced pancreatitis (AP). c, Quantification of number of clones per 20x high-power field (HPF) in Ptf1aCreER; Kras mice (n=7) and TertCreER; Kras mice (n=7) one month after cerulein-induced pancreatitis (AP) (mean ± SD). d, e, Representative metaplastic area (d, dashed line) and PanIN lesion (e, black arrow) in H&E staining of TertCreER; Kras mice one-month post injury (AP) (n=9 mice). f, g, Representative H&E staining (f) and Immunohistochemistry for Tomato (g) of Ptf1aCreER; Krasmice one-month post injury (AP) with high dose tamoxifen (5mg) (n=9 mice). hk, Immunofluorescence analysis of a TertCreER (h, i) and TertCreER; Kras (j, k) mice one month after sham (h, j) or cerulein (i, k) treatment. Acinar cell expansion (red arrows) and PanINs (white arrow) are shown. Scale bar 100µm (a, cf) and 50µm (gj).

Source data

Extended Data Fig. 5 MEK inhibitor prevents PanIN formation from TERT-High cells expressing mutant Kras.

a, Schema of cerulein-induced pancreatitis with MEKi treatment (Trametinib). b, c, H&E (b) and Tomato (c) staining of TertCreER; Kras mice one month after cerulein induced pancreatitis with (Trametinib) and without (Vehicle) MEKi treatment. d, Quantification of Tomato-positive cells per clone with (n=4 mice) and without (n=3 mice) MEK inhibition (mean ± SD). Scale bars, 100µm.

Source data

Extended Data Fig. 6 Specificity of pERK-positive acinar regions in human samples.

pERK 1/2 staining of human pancreas cancer specimen using indicated antibodies and IgG control (n=7 for #4376, n=44 for #4370 and n=3 for IgG control. Scale bars, 100µm.

Extended Data Table 1 Disease status of non-PDAC and autopsy samples
Extended Data Table 2 pERK status and Kras mutation sequences

Supplementary information

Source data

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Neuhöfer, P., Roake, C.M., Kim, S.J. et al. Acinar cell clonal expansion in pancreas homeostasis and carcinogenesis. Nature 597, 715–719 (2021).

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI:

This article is cited by


By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.


Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing