Erschienen in:
03.05.2021 | Original Article
Inhibition of TLR7 and TLR9 Reduces Human Cholangiocarcinoma Cell Proliferation and Tumor Development
verfasst von:
Fatma El Zahraa Mohamed, Rajiv Jalan, Shane Minogue, Fausto Andreola, Abeba Habtesion, Andrew Hall, Alison Winstanley, Steven Olde Damink, Massimo Malagó, Nathan Davies, Tu Vinh Luong, Amar Dhillon, Rajeshwar Mookerjee, Dipok Dhar, Rajai Munir Al-Jehani
Erschienen in:
Digestive Diseases and Sciences
|
Ausgabe 5/2022
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Abstract
Background
Toll-like receptors (TLRs) are key players in innate immunity and modulation of TLR signaling has been demonstrated to profoundly affect proliferation and growth in different types of cancer. However, the role of TLRs in human intrahepatic cholangiocarcinoma (ICC) pathogenesis remains largely unexplored.
Aims
We set out to determine if TLRs play any role in ICCs which could potentially make them useful treatment targets.
Methods
Tissue microarrays containing samples from 9 human ICCs and normal livers were examined immunohistochemically for TLR4, TLR7, and TLR9 expression. Proliferation of human ICC cell line HuCCT1 was measured by MTS assay following treatment with CpG-ODN (TLR9 agonist), imiquimod (TLR7 agonist), chloroquine (TLR7 and TLR9 inhibitor) and IRS-954 (TLR7 and TLR9 antagonist). The in vivo effects of CQ and IRS-954 on tumor development were also examined in a NOD-SCID mouse xenograft model of human ICC.
Results
TLR4 was expressed in all normal human bile duct epithelium but absent in the majority (60%) of ICCs. TLR7 and TLR9 were expressed in 80% of human ICCs. However, TLR7 was absent in all cases of normal human bile duct epithelium and only one was TLR9 positive. HuCCT1 cell proliferation in vitro significantly increased following IMQ or CpG-ODN treatment (P < 0.03 and P < 0.002, respectively) but decreased with CQ (P < 0.02). In the mouse xenograft model there was significant reduction in size of tumors from CQ and IRS-954 treated mice compared to untreated controls.
Conclusion
TLR7 and TLR9 should be further explored for their potential as actionable targets in the treatment of ICC.