The role of myeloid‐derived suppressor cells in gastrointestinal cancer

Abstract

Gastrointestinal (GI) cancer encompasses a range of malignancies that originate in the digestive system, which together represent the most common form of cancer diagnosed worldwide. However, despite numerous advances in both diagnostics and treatment, the incidence and mortality rate of GI cancer are on the rise. Myeloid‐derived suppressor cells (MDSCs) are a heterogeneous population of immature myeloid cells that increase in number under certain pathological conditions, such as infection and inflammation, and this expansion is of particular relevance to cancer. MDSCs are heavily involved in the regulation of the immune system and act to dampen its response to tumors, favoring the escape of tumor cells from immunosurveillance and increasing both metastasis and recurrence. Several recent studies have supported the use of MDSCs as a prognostic and predictive biomarker in patients with cancer, and potentially as a novel treatment target. In the present review, the mechanisms underlying the immunosuppressive functions of MDSCs are described, and recent researches concerning the involvement of MDSCs in the progression, prognosis, and therapies of GI cancer are reviewed. The aim of this work was to present the development of novel treatments targeting MDSCs in GI cancer in the hope of improving outcomes for patients with this condition.

Systemic Interleukins’ Profile in Early and Advanced Colorectal Cancer

“…M-MDSCs are considered to show even more suppressive functions via high expression of Arg1, driving T cell anergy by depleting arginine pools. In addition, MDSCs can secrete high levels of IL-10 and TGF-beta, IFN-gamma [ 166 ] and produce reactive nitrogen species, negatively affecting T cell recruitment and activation [ 167 ]. They also exhibit tumor-promoting functions independent of immune suppression, such as the promotion of metastasis and angiogenesis via the production of VEGF, basic fibroblast growth factor (bFGF), and matrix metalloproteinase 9 (MMP9) [ 168 , 169 ].…”

Correlation between high ratio of circulating PMN-MDSCs and poor prognosis in metastatic hormone sensitive prostate cancer

“…The high frequency of MDSCs was shown to be associated with a poor prognosis with various malignant neoplasms via the immunosuppressive effect in the tumor-associated immune system [11,12]. While the association between the total MDSC subsets and OS in PC patients has been reported in an earlier study [15], no studies have examined the impact of each of the MDSC subsets on the prognosis of patients with mHSPC.…”

“…In head and neck canner and ovarian cancer, it has been reported that e-MDSCs have an immunosuppressive property, but their speci c roles are still uncertain in other tumors [10]. It has been reported that the high frequency of MDSCs in peripheral blood is associated the disease progression and poor prognosis of many malignant neoplasms, including lung cancer and gastric cancer [11,12]. The several studies which have shown the role of MDSCs in localized PC or CRPC have been mainly focused on either PMN-MDSCs or M-MDSCs, however, there have been no reports on the involvement of the three MDSC subsets in untreated metastatic PC patients [13][14][15][16].…”

Therapeutic Values of Myeloid-Derived Suppressor Cells in Hepatocellular Carcinoma: Facts and Hopes

“…CCR2 is mainly expressed on specific cell types, such as monocytes, NK, T cells, and MDSCs, particularly for the subset of M-MDSCs [101,102]. CCR2 binds with several ligands (i.e., CCL2, CCL7, CCL8, and CCL12), with the most potent binding preference with CCL2 [101].…”