@article{ecc4f95d3acd4ebab01d11eff64fe0d5,
title = "Hedgehog transcriptional effector GLI mediates mTOR-Induced PD-L1 expression in gastric cancer organoids",
abstract = "Tumors evade immune surveillance by expressing Programmed Death-Ligand 1 (PD-L1), subsequently inhibiting CD8+ cytotoxic T lymphocyte function. Response of gastric cancer to immunotherapy is relatively low. Our laboratory has reported that Helicobacter pylori-induced PD-L1 expression within the gastric epithelium is mediated by the Hedgehog (Hh) signaling pathway. The PI3K/AKT/mTOR pathway is activated in gastric cancer and may have immunomodulatory potential. We hypothesize that Hh signaling mediates mTOR-induced PD-L1 expression. Patient-derived organoids (PDOs) were generated from gastric biopsies and resected tumor tissues. Autologous organoid/immune cell co-cultures were used to study the immunosuppressive function of MDSCs. NanoString Digital Spatial Profiling (DSP) of immune-related protein markers using FFPE slide-mounted tissues from gastric cancer patients was performed. DSP analysis showed infiltration of immunosuppressive MDSCs expressing Arg1, CD66b, VISTA and IDO1 within cancer tissues. Orthotopic transplantation of patient derived organoids (PDOs) resulted in the engraftment of organoids and the development of histology similar to that observed in the patient's tumor tissue. PDO/immune cell co-cultures revealed that PD-L1-expressing organoids were unresponsive to nivolumab in vitro in the presence of PMN-MDSCs. Depletion of PMN-MDSCs within these co-cultures sensitized the organoids to anti-PD-1/PD-L1-induced cancer cell death. Rapamycin decreased phosphorylated S6K, Gli2 and PD-L1 expression in PDO/immune cell co-cultures. Transcriptional regulation of PD-L1 by GLI1 and GLI2 was blocked by rapamycin. In conclusion, the PDO/immune cell co-cultures may be used to study immunosuppressive MDSC function within the gastric tumor microenvironment. The mTOR signaling pathway mediates GLI-induced PD-L1 expression in gastric cancer.",
keywords = "Cytotoxic T lymphocytes, Myeloid derived suppressor cells, Sonic hedgehog, Tumor microenvironment",
author = "Vivien Koh and Jayati Chakrabarti and Meaghan Torvund and Nina Steele and Hawkins, {Jennifer A.} and Yoshiaki Ito and Jiang Wang and Helmrath, {Michael A.} and Merchant, {Juanita L.} and Ahmed, {Syed A.} and Asim Shabbir and {Yan So}, {Jimmy Bok} and Yong, {Wei Peng} and Yana Zavros",
note = "Funding Information: This research is supported by: Singapore Ministry of Health National Medical Research Council under its Open Fund-Large Collaborative Grant (OF-LCG; MOH-OFLCG18May-0003) awarded to the Singapore Gastric Cancer Consortium; NIH (NIDDK) 2 R01 DK083402-06A1 grant, NIH 1U19AI116491-01 grant and Yeoh Ghim Seng Visiting Professorship in Surgery research fund from the National University of Singapore awarded to YZ; National Cancer Institute Singapore Center Grant Programme awarded to WPY. This project was also supported in part by PHS Grant P30 DK078392 (Integrative Morphology Core) of the Digestive Diseases Research Core Center in Cincinnati. We are sincerely grateful to Jocelyn Fimbres in the Tissue Acquisition and Cellular/Molecular Analysis Shared Resource (TACMASR) Core for their assistance with embedding, sectioning and immunohistochemistry of tissue and organoids. We would also like to acknowledge Patty Jansma (Marley Imaging Core, University Arizona) and, Douglas W Cromey (TACMASR core, University of Arizona) for assistance in microscopy. Research reported also partly supported by the National Cancer Institute of the National Institutes of Health under award number P30 CA023074 (Sweasy). Merchant (R01 DK 118563). We would like to thank Dr. CHAN Shing Leng from the Cancer Science Institute of Singapore for her advice on organoid generation and critically reviewing the manuscript. We would also like to thank Fiona CHIA from the Microscopy Core Facility at the Cancer Science Institute of Singapore for her assistance with confocal microscopy, Chet Closson (Live Microscopy Core, University of Cincinnati and Lisa McMILLIN from the Pathology Research Core at Cincinnati Children's Hospital Medical Center for her assistance with histology. Funding Information: This research is supported by: Singapore Ministry of Health National Medical Research Council under its Open Fund-Large Collaborative Grant (OF-LCG; MOH-OFLCG18May-0003) awarded to the Singapore Gastric Cancer Consortium; NIH (NIDDK) 2 R01 DK083402-06A1 grant, NIH 1U19AI116491-01 grant and Yeoh Ghim Seng Visiting Professorship in Surgery research fund from the National University of Singapore awarded to YZ; National Cancer Institute Singapore Center Grant Programme awarded to WPY. This project was also supported in part by PHS Grant P30 DK078392 (Integrative Morphology Core) of the Digestive Diseases Research Core Center in Cincinnati. We are sincerely grateful to Jocelyn Fimbres in the Tissue Acquisition and Cellular/Molecular Analysis Shared Resource (TACMASR) Core for their assistance with embedding, sectioning and immunohistochemistry of tissue and organoids. We would also like to acknowledge Patty Jansma (Marley Imaging Core, University Arizona) and, Douglas W Cromey (TACMASR core, University of Arizona) for assistance in microscopy. Research reported also partly supported by the National Cancer Institute of the National Institutes of Health under award number P30 CA023074 (Sweasy). Merchant (R01 DK 118563). We would like to thank Dr. CHAN Shing Leng from the Cancer Science Institute of Singapore for her advice on organoid generation and critically reviewing the manuscript. We would also like to thank Fiona CHIA from the Microscopy Core Facility at the Cancer Science Institute of Singapore for her assistance with confocal microscopy, Chet Closson (Live Microscopy Core, University of Cincinnati and Lisa McMILLIN from the Pathology Research Core at Cincinnati Children's Hospital Medical Center for her assistance with histology. Publisher Copyright: {\textcopyright} 2021",
year = "2021",
month = oct,
day = "10",
doi = "10.1016/j.canlet.2021.06.007",
language = "English (US)",
volume = "518",
pages = "59--71",
journal = "Cancer Letters",
issn = "0304-3835",
publisher = "Elsevier Ireland Ltd",
}