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Pancreatic Neoplasms: HELP
Articles by Adnan A. Sheikh
Based on 2 articles published since 2009
(Why 2 articles?)

Between 2009 and 2019, Adnan Sheikh wrote the following 2 articles about Pancreatic Neoplasms.
+ Citations + Abstracts
1 Article S100A8 and S100A9 proteins form part of a paracrine feedback loop between pancreatic cancer cells and monocytes. 2018

Nedjadi, Taoufik / Evans, Anthony / Sheikh, Adnan / Barerra, Lawrence / Al-Ghamdi, Suliman / Oldfield, Lucy / Greenhalf, W / Neoptolemos, John P / Costello, Eithne. ·King Abdullah International Medical Research Centre, King Abdulaziz Medical City, Ministry of National Guard-Health Affairs, P. O. Box 9515, Jeddah, 21423, Saudi Arabia. nedjadita@ngha.med.sa. · Department of Molecular and Clinical Cancer Medicine, Institute of Translational Medicine, The University of Liverpool, Liverpool, UK. · King Abdullah International Medical Research Centre, King Abdulaziz Medical City, Ministry of National Guard-Health Affairs, P. O. Box 9515, Jeddah, 21423, Saudi Arabia. ·BMC Cancer · Pubmed #30558665.

ABSTRACT: BACKGROUND: The secretion of soluble factors enables communication between tumour cells and the surrounding microenvironment and plays an important role in oncogenesis. Pancreatic ductal adenocarcinoma (PDAC) is characterised by a highly reactive microenvironment, harbouring a variety of cell types, including S100A8/S100A9-expressing monocytes. S100A8/S100A9 proteins regulate the behaviour of cancer cells by inducing pre-metastatic cascades associated with cancer spread. The aim of this study was to examine how S100A8/A9 proteins mediate tumour-stroma crosstalk in PDAC. METHODS: Cytokine profiling of pancreatic cancer cell-derived conditioned media was performed using Bio-Plex Pro 27 Plex Human Cytokine assays. Protein expression and activation of downstream signalling effectors and NF-κB were assessed by western blotting analysis and reporter assays respectively. RESULTS: Stimulation of cultured pancreatic cancer cells with S100A8 and S100A9 increased the secretion of the pro-inflammatory cytokines IL-8, TNF-α, and FGF. S100A8, but not S100A9 induced PDGF secretion. Conversely, pancreatic cancer cell-derived conditioned media and the individual cytokines, TNF-α and TGF-β induced the expression of S100A8 and S100A9 proteins in the HL-60 monocytic cell line and primary human monocytes, while FGF and IL-8 induced the expression of S100A9 only. S100A8 and S100A9 activated MAPK and NF-κB signalling in pancreatic cancer. This was partially mediated via activation of the receptor of advanced glycosylation end-product (RAGE). CONCLUSION: S100A8 and S100A9 proteins induce specific cytokine secretion from PDAC cells, which in turn enhances the expression of S100A8/A9. This paracrine crosstalk could have implications for PDAC invasiveness and metastatic potential.

2 Article Smad4 loss is associated with fewer S100A8-positive monocytes in colorectal tumors and attenuated response to S100A8 in colorectal and pancreatic cancer cells. 2010

Ang, Chin Wee / Nedjadi, Taoufik / Sheikh, Adnan A / Tweedle, Elizabeth M / Tonack, Sarah / Honap, Sailish / Jenkins, Rosalind E / Park, B Kevin / Schwarte-Waldhoff, Irmgard / Khattak, Ilyas / Azadeh, Bahram / Dodson, Andrew / Kalirai, Helen / Neoptolemos, John P / Rooney, Paul S / Costello, Eithne. ·The Liverpool Cancer Research-UK Centre, Division of Surgery and Oncology, School of Cancer Studies, University of Liverpool, Liverpool L69 3GA, UK. ·Carcinogenesis · Pubmed #20622003.

ABSTRACT: S100A8 and its dimerization partner S100A9 are emerging as important chemokines in cancer. We previously reported that Smad4-negative pancreatic tumors contain fewer stromal S100A8-positive monocytes than their Smad4-positive counterparts. Here, we studied S100A8/A9-expressing cells in colorectal tumors relating their presence to clinicopathological parameters and Smad4 status. Two-dimensional gel electrophoresis (n = 12) revealed variation in the levels of S100A8 protein in colorectal cancer tumors, whereas immunohistochemical analysis (n = 313) showed variation in the numbers of stromal S100A8-positive and S100A9-positive cells. Loss of Smad4 expression was observed in 42/304 (14%) colorectal tumors and was associated with reduced numbers of S100A8-positive (P = 0.03) but not S100A9-positive stromal cells (P = 0.26). High S100A9 cell counts were associated with large tumor sizes (P = 0.0006) and poor differentiation grade (P = 0.036). However, neither S100A8 nor S100A9 cell counts predicted poor survival, except for patients with Smad4-negative tumors (P = 0.02). To address the impact of environmental S100A8/A9 chemokines on tumor cells, we examined the effects of exogenously added S100A8 and S100A9 proteins on cellular migration and proliferation of colorectal and pancreatic cancer cells. S100A8 and S100A9 enhanced migration and proliferation in Smad4-positive and Smad4-negative cancer cells. However, transient depletion of Smad4 resulted in loss of responsiveness to exogenous S100A8, but not S100A9. S100A8 and S100A9 activated Smad4 signaling as evidenced by phosphorylation of Smad2/3; blockade of the receptor for the advanced glycation end products inhibited this response. In conclusion, Smad4 loss alters the tumor's interaction with stromal myeloid cells and the tumor cells' response to the stromal chemokine, S100A8.