Jun T Low1, Michael Christie2, Matthias Ernst3, Laure Dumoutier4, Adele Preaudet5, Yanhong Ni6, Michael D W Griffin7, Lisa A Mielke3, Andreas Strasser1, Tracy L Putoczki8, Lorraine A O'Reilly9. 1. The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia; Department of Medical Biology, The University of Melbourne, Parkville, Victoria, Australia. 2. The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia; Department of Pathology, University of Melbourne, Parkville, Victoria, Australia. 3. Olivia Newton-John Cancer Research Institute and La Trobe University School of Cancer Medicine, Heidelberg, Victoria, Australia. 4. Institut de Duve, Bruxelles, Belgium. 5. The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia. 6. Visiting scientist from Central Laboratory, Nanjing Stomatological Hospital, Medical School of Nanjing University, Nanjing, China to The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia. 7. Department of Biochemistry and Molecular Biology, University of Melbourne, Parkville, Victoria, Australia; Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, Victoria, Australia. 8. The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia; Department of Medical Biology, The University of Melbourne, Parkville, Victoria, Australia; Department of Surgery, The University of Melbourne, Parkville, Victoria, Australia. 9. The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia; Department of Medical Biology, The University of Melbourne, Parkville, Victoria, Australia. Electronic address: oreilly@wehi.edu.au.
Abstract
BACKGROUND & AIMS: Activity of nuclear factor κB transcription factors and signaling via signal transducer and activator of transcription (STAT) are frequently altered in gastric cancer cells. Mice lacking NFKB1 (Nfkb1-/- mice) develop invasive gastric cancer, and their gastric tissues have increased levels of cytokines, such as interleukin (IL) 6, IL22, IL11, and tumor necrosis factor (TNF), as well as increased activation of STAT1. We investigated whether these cytokines were required for STAT1 activation in gastric tissues of mice and critical for gastric tumorigenesis. METHODS: We crossed Nfkb1-/- mice with Il6-/-, Il22-/-, Il11Rα-/-, and Tnf-/- mice. Stomach tissues from compound mutant mice were analyzed by histology, immunoblotting, and RNA sequencing. Lymphoid, myeloid, and epithelial cells were isolated from stomachs, and the levels of cytokines were determined by flow cytometric analysis. RESULTS: Nfkb1-/- mice developed gastritis, oxyntic atrophy, gastric dysplasia, and invasive tumors, whereas Nfkb1-/-Stat1-/- mice did not, even when followed for as long as 2 years. The levels of Il6, Il11, Il22, and Tnf messenger RNA were increased in the body and antrum of the stomachs from Nfkb1-/- mice, from 3-6 months of age. However, Nfkb1-/-Il6-/-, Nfkb1-/-Il22-/-, and Nfkb1-/-Il11Rα-/- mice still developed gastric tumors, although the absence of IL11 receptor (IL11R) significantly reduced development of invasive gastric tumors. Stomachs from Nfkb1-/-Tnf-/- mice exhibited significantly less gastritis and oxyntic atrophy and fewer tumors than Nfkb1-/- mice. This correlated with reduced activation of STAT1 and STAT3 and fewer numbers of T cells and B cells infiltrating the gastric body. Loss of STAT1 or TNF significantly reduced expression of PD-L1 on epithelial and myeloid (CD11b+) cells in the gastric mucosa of Nfkb1-/- mice-indeed, to the levels observed on the corresponding cells from wild-type mice. CONCLUSIONS: In studies of gastric tumor development in knockout mice, we found that loss of NFKB1 causes increased expression of TNF in the stomach and thereby drives activation of STAT1, resulting in an inflammatory immune response and the development of gastric cancer. IL11R appears to be required for the progression of gastric tumors to the invasive stage. These findings suggest that inhibitors of TNF, and possibly also inhibitors of IL11/IL11Rα, might be useful in the treatment of gastric cancer.
BACKGROUND & AIMS: Activity of nuclear factor κB transcription factors and signaling via signal transducer and activator of transcription (STAT) are frequently altered in gastric cancer cells. Mice lacking NFKB1 (Nfkb1-/- mice) develop invasive gastric cancer, and their gastric tissues have increased levels of cytokines, such as interleukin (IL) 6, IL22, IL11, and tumor necrosis factor (TNF), as well as increased activation of STAT1. We investigated whether these cytokines were required for STAT1 activation in gastric tissues of mice and critical for gastric tumorigenesis. METHODS: We crossed Nfkb1-/- mice with Il6-/-, Il22-/-, Il11Rα-/-, and Tnf-/- mice. Stomach tissues from compound mutant mice were analyzed by histology, immunoblotting, and RNA sequencing. Lymphoid, myeloid, and epithelial cells were isolated from stomachs, and the levels of cytokines were determined by flow cytometric analysis. RESULTS:Nfkb1-/- mice developed gastritis, oxyntic atrophy, gastric dysplasia, and invasive tumors, whereas Nfkb1-/-Stat1-/- mice did not, even when followed for as long as 2 years. The levels of Il6, Il11, Il22, and Tnf messenger RNA were increased in the body and antrum of the stomachs from Nfkb1-/- mice, from 3-6 months of age. However, Nfkb1-/-Il6-/-, Nfkb1-/-Il22-/-, and Nfkb1-/-Il11Rα-/- mice still developed gastric tumors, although the absence of IL11 receptor (IL11R) significantly reduced development of invasive gastric tumors. Stomachs from Nfkb1-/-Tnf-/- mice exhibited significantly less gastritis and oxyntic atrophy and fewer tumors than Nfkb1-/- mice. This correlated with reduced activation of STAT1 and STAT3 and fewer numbers of T cells and B cells infiltrating the gastric body. Loss of STAT1 or TNF significantly reduced expression of PD-L1 on epithelial and myeloid (CD11b+) cells in the gastric mucosa of Nfkb1-/- mice-indeed, to the levels observed on the corresponding cells from wild-type mice. CONCLUSIONS: In studies of gastric tumor development in knockout mice, we found that loss of NFKB1 causes increased expression of TNF in the stomach and thereby drives activation of STAT1, resulting in an inflammatory immune response and the development of gastric cancer. IL11R appears to be required for the progression of gastric tumors to the invasive stage. These findings suggest that inhibitors of TNF, and possibly also inhibitors of IL11/IL11Rα, might be useful in the treatment of gastric cancer.
Authors: Tracy L Putoczki; Lorraine A O'Reilly; Jun T Low; Gwo-Yaw Ho; Mark Scott; Chin Wee Tan; Lachlan Whitehead; Kathy Barber; Hon Y K Yip; Johanna F Dekkers; Yumiko Hirokawa; John Silke; Antony W Burgess; Andreas Strasser Journal: Cell Death Dis Date: 2021-11-17 Impact factor: 8.469