Evans, AR and Sharma, S and Hemers, E, E (2016) The role of High-Mobility Group Box 1 protein in mesenchymal-epithelial signalling in the tumour microenvironment. In: European Journal of Cancer Supplements , 61 (1359-6). (EACR 24th biennial conference, 09 July 2016 - 12 July 2016, Manchester UK). (Accepted)
HMGB1 Poster 2016.pdf - Presentation
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Introduction Glucose depravation, hypoxia, and acidosis are characteristic features of the central core most solid tumours. Myofibroblasts are stromal cells present in many such solid tumours including those of the colon, and they are known to be involved in all stages of tumour progression. HMGB1 is a nuclear protein that plays an important role in nucleosome stabilisation and gene transcription. HMGB1 is also released from immune cells and is involved in the inflammatory process. This work reports a novel finding that the microenvironmental condition of glucose depravation is responsible for the active release of HMGB1 from different types of cancer cell lines (HT-29, MCF-7 and A549) under normoxic conditions. Materials and method Human colonic myofibroblasts cells CCD18COCo, and cancer cells, colon HT-29, lung A549 and breast MCF7 were obtained from the ATCC and bladder cancer cells EJ138 from the ECACC. The human recombinant HMGB1, anti-HMGB1 antibody, anti-RAGE primary antibody and anti-TLR4 antibody were purchased from R&D systems. MEK1/2 inhibitor (U0126) and PI3K inhibitor (LY294002) were purchased from Cell Signalling Technology (USA). Medium was collected from HT-29, MCF-7, EJ138 and A549 cells after 48h treatment with various conditioned or fresh medium and analysed by western blotting for the presence of HMGB1. The MTT assay was used measure proliferation of myofibroblasts after treatment with conditioned medium with or without an MEK1/2 inhibitor or a PI3K inhibitor. Migration of CCD18Co cells in response to medium previously conditioned on HT-29 cells for 20h was studied using 8µm pore Boyden chamber inserts in 24-well plate system (BD Bioscience, California, USA). In addition, invasion assays of myofibroblast cells were performed using 8µm pore matrigel matrix Biocoat® inserts according to the manufacturer’s instruction (Becton Dickinson). Results and discussion Recombinant HMGB1 (10ng/ml) was shown to trigger proliferation in myofibroblasts cells via activation of PI3K and MEK1/2. Conditioned medium collected from glucose deprived HT-29 colon cancer cells was shown to stimulate migration and invasion of colonic myofibroblasts, and these processes were significantly inhibited by immunoneutralising antibodies to HMGB1, RAGE and TLR4, along with specific inhibitors of PI3K and MEK1/2. Conclusion Together these data suggests that HMGB1 released from the cancer cells under glucose depravation is involved in stimulating colonic myofibroblast migration and invasion and that this was through activation of RAGE and TLR4, resulting in activation of the MAPK and PI3K signalling pathways. Thus, it is proposed that HMGB1 may be released by cancer cells in areas of low glucose in solid tumours with the resulting activation of myofibroblasts. Therefore, HMGB1 may be considered as potential therapeutic target to inhibit solid tumour growth.
|Item Type:||Conference or Workshop Item (Poster)|
|Uncontrolled Keywords:||1112 Oncology And Carcinogenesis|
|Subjects:||R Medicine > RM Therapeutics. Pharmacology|
|Divisions:||Natural Sciences and Psychology
Pharmacy & Biomolecular Sciences
|Date Deposited:||13 Jul 2016 08:27|
|Last Modified:||13 Jul 2016 08:27|
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