RET isoforms contribute differentially to invasive processes in pancreatic ductal adenocarcinoma

Abstract

Pancreatic ductal adenocarcinoma (PDAC) is a therapeutically challenging disease with poor survival rates, owing to late diagnosis and early dissemination. These tumors frequently undergo perineural invasion, spreading along nerves regionally and to distant sites. The RET receptor tyrosine kinase is implicated in increased aggressiveness, local invasion, and metastasis in multiple cancers, including PDAC. RET mediates directional motility and invasion towards sources of its neurotrophic factor ligands, suggesting that it may enhance perineural invasion of tumor cells towards nerves. RET is expressed as two main isoforms, RET9 and RET51, which differ in their protein interactions and oncogenic potentials, however, the contributions of RET isoforms to neural invasion have not been investigated. In this study, we generated total RET and isoform-specific knockdown PDAC cell lines and assessed the contributions of RET isoforms to PDAC invasive spread. Our data show that RET activity induces cell polarization and actin remodeling through activation of CDC42 and RHOA GTPases to promote directional motility in PDAC cells. Further, we show that RET interacts with the adaptor protein TKS5 to induce invadopodia formation, enhance matrix degradation and promote tumor cell invasion through a SRC and GRB2-dependent mechanism. Finally, we show that RET51 is the predominant isoform contributing to these RET-mediated invasive processes in PDAC. Together, our work suggests that RET expression in pancreatic cancers may enhance tumor aggressiveness by promoting perineural invasion, and that RET expression may be a valuable marker of invasiveness, and a potential therapeutic target in the treatment of these cancers.

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Fig. 1: RET knockdown induces isoform-specific changes in morphology and cell motility in pancreatic ductal adenocarcinoma cells.
Fig. 2: RET induces cell polarization towards GDNF.
Fig. 3: RET induces formation of F-actin and TKS5-rich structures.
Fig. 4: RET associates with TKS5.
Fig. 5: RET activity enhances formation of invadopodia.
Fig. 6: RET51 enhances proteolytic activity in PDAC cells.
Fig. 7: RET51 is primarily responsible for PDAC cell invasion.
Fig. 8: RET functions in PDAC cells.

References

  1. 1.

    Saad AM, Turk T, Al-Husseini MJ, Abdel-Rahman O. Trends in pancreatic adenocarcinoma incidence and mortality in the United States in the last four decades; a SEER-based study. BMC Cancer. 2018;18:688.

    PubMed  PubMed Central  Google Scholar 

  2. 2.

    Ilic M, Ilic I. Epidemiology of pancreatic cancer. World J Gastroenterol. 2016;22:9694–705.

    PubMed  PubMed Central  Google Scholar 

  3. 3.

    Huang L, Jansen L, Balavarca Y, Babaei M, van der Geest L, Lemmens V, et al. Stratified survival of resected and overall pancreatic cancer patients in Europe and the USA in the early twenty-first century: a large, international population-based study. BMC Med. 2018;16:125.

    PubMed  PubMed Central  Google Scholar 

  4. 4.

    Vincent A, Herman J, Schulick R, Hruban RH, Goggins M. Pancreatic cancer. Lancet. 2011;378:607–20.

    PubMed  PubMed Central  Google Scholar 

  5. 5.

    Marchesi F, Piemonti L, Mantovani A, Allavena P. Molecular mechanisms of perineural invasion, a forgotten pathway of dissemination and metastasis. Cytokine Growth Factor Rev. 2010;21:77–82.

    CAS  PubMed  Google Scholar 

  6. 6.

    Liebig C, Ayala G, Wilks JA, Berger DH, Albo D. Perineural invasion in cancer: a review of the literature. Cancer. 2009;115:3379–91.

    CAS  PubMed  Google Scholar 

  7. 7.

    Hirai I, Kimura W, Ozawa K, Kudo S, Suto K, Kuzu H, et al. Perineural invasion in pancreatic cancer. Pancreas. 2002;24:15–25.

    PubMed  Google Scholar 

  8. 8.

    Liang D, Shi S, Xu J, Zhang B, Qin Y, Ji S, et al. New insights into perineural invasion of pancreatic cancer: More than pain. Biochim Biophys Acta. 2016;1865:111–22.

    CAS  PubMed  Google Scholar 

  9. 9.

    Amit M, Na’ara S, Fridman E, Vladovski E, Wasserman T, Milman N, et al. RET, a targetable driver of pancreatic adenocarcinoma. Int J Cancer. 2019;144:3014–22.

    CAS  PubMed  Google Scholar 

  10. 10.

    Amit M, Na’ara S, Leider-Trejo L, Binenbaum Y, Kulish N, Fridman E, et al. Upregulation of RET induces perineurial invasion of pancreatic adenocarcinoma. Oncogene. 2017;36:3232–9.

    CAS  PubMed  Google Scholar 

  11. 11.

    Ceyhan GO, Demir IE, Altintas B, Rauch U, Thiel G, Muller MW, et al. Neural invasion in pancreatic cancer: a mutual tropism between neurons and cancer cells. Biochem Biophys Res Commun. 2008;374:442–7.

    CAS  PubMed  Google Scholar 

  12. 12.

    Ceyhan GO, Giese NA, Erkan M, Kerscher AG, Wente MN, Giese T, et al. The neurotrophic factor artemin promotes pancreatic cancer invasion. Ann Surg. 2006;244:274–81.

    PubMed  PubMed Central  Google Scholar 

  13. 13.

    Gil Z, Cavel O, Kelly K, Brader P, Rein A, Gao SP, et al. Paracrine regulation of pancreatic cancer cell invasion by peripheral nerves. J Natl Cancer Inst. 2010;102:107–18.

    CAS  PubMed  PubMed Central  Google Scholar 

  14. 14.

    Zeng Q, Cheng Y, Zhu Q, Yu Z, Wu X, Huang K, et al. The relationship between overexpression of glial cell-derived neurotrophic factor and its RET receptor with progression and prognosis of human pancreatic cancer. J Int Med Res. 2008;36:656–64.

    CAS  PubMed  Google Scholar 

  15. 15.

    Ito Y, Okada Y, Sato M, Sawai H, Funahashi H, Murase T, et al. Expression of glial cell line-derived neurotrophic factor family members and their receptors in pancreatic cancers. Surgery. 2005;138:788–94.

    PubMed  Google Scholar 

  16. 16.

    Mulligan LM. GDNF and the RET receptor in cancer: new insights and therapeutic potential. Front Physiol. 2019;9:1873.

    PubMed  PubMed Central  Google Scholar 

  17. 17.

    Lian EY, Maritan SM, Cockburn JG, Kasaian K, Crupi MJ, Hurlbut D, et al. Differential roles of RET isoforms in medullary and papillary thyroid carcinomas. Endocr Relat Cancer. 2017;24:53–69.

    CAS  PubMed  Google Scholar 

  18. 18.

    Kohno T, Ichikawa H, Totoki Y, Yasuda K, Hiramoto M, Nammo T, et al. KIF5B-RET fusions in lung adenocarcinoma. Nat Med. 2012;18:375–7.

    CAS  PubMed  PubMed Central  Google Scholar 

  19. 19.

    Morandi A, Plaza-Menacho I, Isacke CM. RET in breast cancer: functional and therapeutic implications. Trends Mol Med. 2011;17:149–57.

    CAS  PubMed  Google Scholar 

  20. 20.

    Moodley S, Lian EY, Crupi MJF, Hyndman BD, Mulligan LM. RET isoform-specific interaction with scaffold protein Ezrin promotes cell migration and chemotaxis in lung adenocarcinoma. Lung Cancer. 2020;142:123–31.

    PubMed  Google Scholar 

  21. 21.

    Tahira T, Ishizaka Y, Itoh F, Sugimura T, Nagao M. Characterization of ret proto-oncogene mRNAs encoding two isoforms of the protein product in a human neuroblastoma cell line. Oncogene. 1990;5:97–102.

    CAS  PubMed  Google Scholar 

  22. 22.

    Myers SM, Eng C, Ponder BA, Mulligan LM. Characterization of RET proto-oncogene 3’ splicing variants and polyadenylation sites: a novel C-terminus for RET. Oncogene. 1995;11:2039–45.

    CAS  PubMed  Google Scholar 

  23. 23.

    Besset V, Scott RP, Ibanez CF. Signaling complexes and protein-protein interactions involved in the activation of the Ras and phosphatidylinositol 3-kinase pathways by the c-Ret receptor tyrosine kinase. J Biol Chem. 2000;275:39159–66.

    CAS  PubMed  Google Scholar 

  24. 24.

    Boulay A, Breuleux M, Stephan C, Fux C, Brisken C, Fiche M, et al. The Ret receptor tyrosine kinase pathway functionally interacts with the ERalpha pathway in breast cancer. Cancer Res. 2008;68:3743–51.

    CAS  PubMed  Google Scholar 

  25. 25.

    Ibanez CF. Structure and physiology of the RET receptor tyrosine kinase. Cold Spring Harb Perspect Biol. 2013;5:a009134.

    PubMed  PubMed Central  Google Scholar 

  26. 26.

    Richardson DS, Rodrigues DM, Hyndman BD, Crupi MJ, Nicolescu AC, Mulligan LM. Alternative splicing results in RET isoforms with distinct trafficking properties. Mol Biol Cell. 2012;23:3838–50.

    CAS  PubMed  PubMed Central  Google Scholar 

  27. 27.

    Crupi MJ, Yoganathan P, Bone LN, Lian E, Fetz A, Antonescu CN, et al. Distinct temporal regulation of RET isoform internalization: roles of clathrin and AP2. Traffic. 2015;16:1155–73.

    CAS  PubMed  Google Scholar 

  28. 28.

    Tsui-Pierchala BA, Ahrens RC, Crowder RJ, Milbrandt J, Johnson EM Jr. The long and short isoforms of Ret function as independent signaling complexes. J Biol Chem. 2002;277:34618–25.

    CAS  PubMed  Google Scholar 

  29. 29.

    Hyndman BD, Crupi MJF, Peng S, Bone LN, Rekab AN, Lian EY, et al. Differential recruitment of E3 ubiquitin ligase complexes regulates RET isoform internalization. J Cell Sci. 2017;130:3282–96.

    CAS  PubMed  Google Scholar 

  30. 30.

    Crupi MJF, Maritan SM, Reyes-Alvarez E, Lian EY, Hyndman BD, Rekab AN, et al. GGA3-mediated recycling of the RET receptor tyrosine kinase contributes to cell migration and invasion. Oncogene. 2020;39:1361–77.

    CAS  PubMed  Google Scholar 

  31. 31.

    Griseri P, Garrone O, Lo Sardo A, Monteverde M, Rusmini M, Tonissi F, et al. Genetic and epigenetic factors affect RET gene expression in breast cancer cell lines and influence survival in patients. Oncotarget. 2016;7:26465–79.

    PubMed  PubMed Central  Google Scholar 

  32. 32.

    Bhinge K, Yang L, Terra S, Nasir A, Muppa P, Aubry MC, et al. EGFR mediates activation of RET in lung adenocarcinoma with neuroendocrine differentiation characterized by ASCL1 expression. Oncotarget. 2017;8:27155–65.

    PubMed  PubMed Central  Google Scholar 

  33. 33.

    Ben-Chetrit N, Chetrit D, Russell R, Korner C, Mancini M, Abdul-Hai A, et al. Synaptojanin 2 is a druggable mediator of metastasis and the gene is overexpressed and amplified in breast cancer. Sci Signal. 2015;8:ra7.

    PubMed  Google Scholar 

  34. 34.

    Parachoniak CA, Luo Y, Abella JV, Keen JH, Park M. GGA3 functions as a switch to promote Met receptor recycling, essential for sustained ERK and cell migration. Dev Cell. 2011;20:751–63.

    CAS  PubMed  PubMed Central  Google Scholar 

  35. 35.

    Condeelis JS, Wyckoff JB, Bailly M, Pestell R, Lawrence D, Backer J, et al. Lamellipodia in invasion. Semin Cancer Biol. 2001;11:119–28.

    CAS  PubMed  Google Scholar 

  36. 36.

    Abella JV, Parachoniak CA, Sangwan V, Park M. Dorsal ruffle microdomains potentiate Met receptor tyrosine kinase signaling and down-regulation. J Biol Chem. 2010;285:24956–67.

    CAS  PubMed  PubMed Central  Google Scholar 

  37. 37.

    Murphy DA, Courtneidge SA. The ‘ins’ and ‘outs’ of podosomes and invadopodia: characteristics, formation and function. Nat Rev Mol Cell Biol. 2011;12:413–26.

    CAS  PubMed  PubMed Central  Google Scholar 

  38. 38.

    Parachoniak CA, Park M. Dynamics of receptor trafficking in tumorigenicity. Trends Cell Biol. 2012;22:231–40.

    CAS  PubMed  Google Scholar 

  39. 39.

    Lamorte L, Royal I, Naujokas M, Park M. Crk adapter proteins promote an epithelial-mesenchymal-like transition and are required for HGF-mediated cell spreading and breakdown of epithelial adherens junctions. Mol Biol Cell. 2002;13:1449–61.

    CAS  PubMed  PubMed Central  Google Scholar 

  40. 40.

    Radhakrishna H, Al-Awar O, Khachikian Z, Donaldson JG. ARF6 requirement for Rac ruffling suggests a role for membrane trafficking in cortical actin rearrangements. J Cell Sci. 1999;112:855–66.

    CAS  PubMed  Google Scholar 

  41. 41.

    Menard L, Parker PJ, Kermorgant S. Receptor tyrosine kinase c-Met controls the cytoskeleton from different endosomes via different pathways. Nat Commun. 2014;5:3907.

    CAS  PubMed  Google Scholar 

  42. 42.

    Gorelik R, Gautreau A. Quantitative and unbiased analysis of directional persistence in cell migration. Nat Protoc. 2014;9:1931–43.

    CAS  PubMed  Google Scholar 

  43. 43.

    Mayor R, Carmona-Fontaine C. Keeping in touch with contact inhibition of locomotion. Trends Cell Biol. 2010;20:319–28.

    CAS  PubMed  PubMed Central  Google Scholar 

  44. 44.

    Rottner K, Hall A, Small JV. Interplay between Rac and Rho in the control of substrate contact dynamics. Curr Biol. 1999;9:640–8, S1.

    CAS  PubMed  Google Scholar 

  45. 45.

    Raftopoulou M, Hall A. Cell migration: Rho GTPases lead the way. Dev Biol. 2004;265:23–32.

    CAS  PubMed  Google Scholar 

  46. 46.

    Di Martino J, Paysan L, Gest C, Lagree V, Juin A, Saltel F, et al. Cdc42 and Tks5: a minimal and universal molecular signature for functional invadosomes. Cell Adh Migr. 2014;8:280–92.

    PubMed  PubMed Central  Google Scholar 

  47. 47.

    Courtneidge SA, Azucena EF, Pass I, Seals DF, Tesfay L. The SRC substrate Tks5, podosomes (invadopodia), and cancer cell invasion. Cold Spring Harb Symp Quant Biol. 2005;70:167–71.

    CAS  PubMed  Google Scholar 

  48. 48.

    Murphy DA, Diaz B, Bromann PA, Tsai JH, Kawakami Y, Maurer J, et al. A Src-Tks5 pathway is required for neural crest cell migration during embryonic development. PLoS ONE. 2011;6:e22499.

    CAS  PubMed  PubMed Central  Google Scholar 

  49. 49.

    Encinas M, Crowder RJ, Milbrandt J, Johnson EM. Tyrosine 981, a novel Ret autophosphorylation site, binds c-Src to mediate neuronal survival. J Biol Chem. 2004;279:18262–9.

    CAS  PubMed  Google Scholar 

  50. 50.

    Poteryaev D, Titievsky A, Sun YF, Thomas-Crusells J, Lindahl M, Billaud M, et al. GDNF triggers a novel ret-independent Src kinase family-coupled signaling via a GPI-linked GDNF receptor alpha1. FEBS Lett. 1999;463:63–6.

    CAS  PubMed  Google Scholar 

  51. 51.

    Rajadurai CV, Havrylov S, Zaoui K, Vaillancourt R, Stuible M, Naujokas M, et al. Met receptor tyrosine kinase signals through a cortactin-Gab1 scaffold complex, to mediate invadopodia. J Cell Sci. 2012;125:2940–53.

    CAS  PubMed  PubMed Central  Google Scholar 

  52. 52.

    Paz H, Pathak N, Yang J. Invading one step at a time: the role of invadopodia in tumor metastasis. Oncogene. 2014;33:4193–202.

    CAS  PubMed  Google Scholar 

  53. 53.

    Oikawa T, Itoh T, Takenawa T. Sequential signals toward podosome formation in NIH-src cells. J cell Biol. 2008;182:157–69.

    CAS  PubMed  PubMed Central  Google Scholar 

  54. 54.

    Burger KL, Learman BS, Boucherle AK, Sirintrapun SJ, Isom S, Diaz B, et al. Src-dependent Tks5 phosphorylation regulates invadopodia-associated invasion in prostate cancer cells. Prostate. 2014;74:134–48.

    CAS  PubMed  Google Scholar 

  55. 55.

    Stylli SS, Stacey TT, Verhagen AM, Xu SS, Pass I, Courtneidge SA, et al. Nck adaptor proteins link Tks5 to invadopodia actin regulation and ECM degradation. J Cell Sci. 2009;122:2727–40.

    CAS  PubMed  PubMed Central  Google Scholar 

  56. 56.

    Jacquemet G, Hamidi H, Ivaska J. Filopodia in cell adhesion, 3D migration and cancer cell invasion. Curr Opin Cell Biol. 2015;36:23–31.

    CAS  PubMed  Google Scholar 

  57. 57.

    Eddy RJ, Weidmann MD, Sharma VP, Condeelis JS. Tumor cell invadopodia: invasive protrusions that orchestrate metastasis. Trends Cell Biol. 2017;27:595–607.

    CAS  PubMed  PubMed Central  Google Scholar 

  58. 58.

    Itoh Y. Membrane-type matrix metalloproteinases: their functions and regulations. Matrix Biol. 2015;44–46:207–23.

    PubMed  Google Scholar 

  59. 59.

    Bakst RL, Wong RJ. Mechanisms of perineural invasion. J Neurol Surg B Skull Base. 2016;77:96–106.

    PubMed  PubMed Central  Google Scholar 

  60. 60.

    Rodrigues DM, Li AY, Nair DG, Blennerhassett MG. Glial cell line-derived neurotrophic factor is a key neurotrophin in the postnatal enteric nervous system. Neurogastroenterol Motil. 2011;23:e44–56.

    CAS  PubMed  Google Scholar 

  61. 61.

    Honma Y, Araki T, Gianino S, Bruce A, Heuckeroth RO Jr, Johnson E, et al. Artemin is a vascular-derived neurotropic factor for developing sympathetic neurons. Neuron. 2002;35:267–82.

    CAS  PubMed  Google Scholar 

  62. 62.

    Suter-Crazzolara C, Unsicker K. GDNF is expressed in two forms in many tissues outside the CNS. NeuroReport. 1994;5:2486–8.

    CAS  PubMed  Google Scholar 

  63. 63.

    Chermenina M, Schouten P, Nevalainen N, Johansson F, Oradd G, Stromberg I. GDNF is important for striatal organization and maintenance of dopamine neurons grown in the presence of the striatum. Neuroscience. 2014;270:1–11.

    CAS  PubMed  Google Scholar 

  64. 64.

    Nevalainen N, Chermenina M, Rehnmark A, Berglof E, Marschinke F, Stromberg I. Glial cell line-derived neurotrophic factor is crucial for long-term maintenance of the nigrostriatal system. Neuroscience. 2010;171:1357–66.

    CAS  PubMed  PubMed Central  Google Scholar 

  65. 65.

    Meka DP, Muller-Rischart AK, Nidadavolu P, Mohammadi B, Motori E, Ponna SK, et al. Parkin cooperates with GDNF/RET signaling to prevent dopaminergic neuron degeneration. J Clin Invest. 2015;125:1873–85.

    PubMed  PubMed Central  Google Scholar 

  66. 66.

    Drinkut A, Tillack K, Meka DP, Schulz JB, Kugler S, Kramer ER. Ret is essential to mediate GDNF’s neuroprotective and neuroregenerative effect in a Parkinson disease mouse model. Cell Death Dis. 2016;7:e2359.

    CAS  PubMed  PubMed Central  Google Scholar 

  67. 67.

    Kramer ER, Liss B. GDNF-Ret signaling in midbrain dopaminergic neurons and its implication for Parkinson disease. FEBS Lett. 2015;589:3760–72.

    CAS  PubMed  Google Scholar 

  68. 68.

    Leong HS, Robertson AE, Stoletov K, Leith SJ, Chin CA, Chien AE, et al. Invadopodia are required for cancer cell extravasation and are a therapeutic target for metastasis. Cell Rep. 2014;8:1558–70.

    CAS  PubMed  Google Scholar 

  69. 69.

    Williams KC, Cepeda MA, Javed S, Searle K, Parkins KM, Makela AV, et al. Invadopodia are chemosensing protrusions that guide cancer cell extravasation to promote brain tropism in metastasis. Oncogene. 2019;38:3598–615.

    CAS  PubMed  PubMed Central  Google Scholar 

  70. 70.

    He S, Chen CH, Chernichenko N, He S, Bakst RL, Barajas F, et al. GFRalpha1 released by nerves enhances cancer cell perineural invasion through GDNF-RET signaling. Proc Natl Acad Sci USA. 2014;111:E2008–17.

    CAS  PubMed  Google Scholar 

  71. 71.

    Cavel O, Shomron O, Shabtay A, Vital J, Trejo-Leider L, Weizman N, et al. Endoneurial macrophages induce perineural invasion of pancreatic cancer cells by secretion of GDNF and activation of RET tyrosine kinase receptor. Cancer Res. 2012;72:5733–43.

    CAS  PubMed  Google Scholar 

  72. 72.

    Sawai H, Okada Y, Kazanjian K, Kim J, Hasan S, Hines OJ, et al. The G691S RET polymorphism increases glial cell line-derived neurotrophic factor-induced pancreatic cancer cell invasion by amplifying mitogen-activated protein kinase signaling. Cancer Res. 2005;65:11536–44.

    CAS  PubMed  Google Scholar 

  73. 73.

    Gupton SL, Gertler FB. Filopodia: the fingers that do the walking. Sci STKE. 2007;2007:re5.

    PubMed  Google Scholar 

  74. 74.

    Sit ST, Manser E. Rho GTPases and their role in organizing the actin cytoskeleton. J Cell Sci. 2011;124:679–83.

    CAS  PubMed  Google Scholar 

  75. 75.

    Mattila PK, Lappalainen P. Filopodia: molecular architecture and cellular functions. Nat Rev Mol Cell Biol. 2008;9:446–54.

    CAS  PubMed  Google Scholar 

  76. 76.

    Partridge MA, Marcantonio EE. Initiation of attachment and generation of mature focal adhesions by integrin-containing filopodia in cell spreading. Mol Biol Cell. 2006;17:4237–48.

    CAS  PubMed  PubMed Central  Google Scholar 

  77. 77.

    Arjonen A, Kaukonen R, Ivaska J. Filopodia and adhesion in cancer cell motility. Cell Adh Migr. 2011;5:421–30.

    PubMed  PubMed Central  Google Scholar 

  78. 78.

    Fischer RS, Lam PY, Huttenlocher A, Waterman CM. Filopodia and focal adhesions: an integrated system driving branching morphogenesis in neuronal pathfinding and angiogenesis. Dev Biol. 2019;451:86–95.

    CAS  PubMed  Google Scholar 

  79. 79.

    Friedl P, Alexander S. Cancer invasion and the microenvironment: plasticity and reciprocity. Cell. 2011;147:992–1009.

    CAS  PubMed  Google Scholar 

  80. 80.

    Beaty BT, Condeelis J. Digging a little deeper: the stages of invadopodium formation and maturation. Eur J Cell Biol. 2014;93:438–44.

    CAS  PubMed  PubMed Central  Google Scholar 

  81. 81.

    Hoshino D, Branch KM, Weaver AM. Signaling inputs to invadopodia and podosomes. J Cell Sci. 2013;126:2979–89.

    CAS  PubMed  PubMed Central  Google Scholar 

  82. 82.

    Yang C, Svitkina T. Filopodia initiation: focus on the Arp2/3 complex and formins. Cell Adh Migr. 2011;5:402–8.

    PubMed  PubMed Central  Google Scholar 

  83. 83.

    Sharma VP, Eddy R, Entenberg D, Kai M, Gertler FB, Condeelis J. Tks5 and SHIP2 regulate invadopodium maturation, but not initiation, in breast carcinoma cells. Curr Biol. 2013;23:2079–89.

    CAS  PubMed  Google Scholar 

  84. 84.

    Richardson DS, Lai AZ, Mulligan LM. RET ligand-induced internalization and its consequences for downstream signaling. Oncogene. 2006;25:3206–11.

    CAS  PubMed  Google Scholar 

  85. 85.

    Esseghir S, Todd SK, Hunt T, Poulsom R, Plaza-Menacho I, Reis-Filho JS, et al. A role for glial cell derived neurotrophic factor induced expression by inflammatory cytokines and RET/GFR alpha 1 receptor up-regulation in breast cancer. Cancer Res. 2007;67:11732–41.

    CAS  PubMed  Google Scholar 

  86. 86.

    Gujral TS, van Veelen W, Richardson DS, Myers SM, Meens JA, Acton DS, et al. A novel RET kinase-beta-catenin signaling pathway contributes to tumorigenesis in thyroid carcinoma. Cancer Res. 2008;68:1338–46.

    CAS  PubMed  Google Scholar 

  87. 87.

    Hickey JG, Myers SM, Tian X, Zhu SJ, Shaw JLV, Andrew SD. et al. RET-mediated gene expression pattern is affected by isoform but not oncogenic mutation. Genes Chromosomes Cancer. 2009;48:429–40.

    CAS  PubMed  Google Scholar 

  88. 88.

    Maritan SM, Lian EY, Mulligan LM. An efficient and flexible cell aggregation method for 3D spheroid production. J Vis Exp. 2017;121:e55544.

    Google Scholar 

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Acknowledgements

The authors would like to thank Dr. Marco Magalhaes (University of Toronto) for the gift of TKS5 constructs and Dr. Donald Maurice (Queen’s University) for providing human smooth muscle cell lines.

Funding

This work was supported by an operating grant from the Cancer Research Society of Canada (19439) and a Canadian Institutes for Health Research operating grant (MOP-142303 (LMM)) and postdoctoral fellowship (398979 (SM)), and Canadian Graduate Scholarship (SMM) and by Ontario Graduate Scholarships and studentships from the Terry Fox Research Institute Training Program in Transdisciplinary Cancer Research (EYL, SMM).

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Correspondence to Lois M. Mulligan.

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Lian, E.Y., Hyndman, B.D., Moodley, S. et al. RET isoforms contribute differentially to invasive processes in pancreatic ductal adenocarcinoma. Oncogene 39, 6493–6510 (2020). https://doi.org/10.1038/s41388-020-01448-z

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