Background: Regulatory T cells(Tregs) and myeloid-derived suppressor cells(MDSCs) represent two immunosuppressive cell populations that are important in the establishment and maintenance of cancer immune tolerance. MDSCs can express IDO and promote immune tolerance via expansion of Treg cell.Method: We use needle biopsy breast cancer tissues prior to neoadjuvant chemotherapy(NCT) staining for CD33, Foxp3 and IDO by immunohistochemistry to evaluate whether they were correlated with subsequent treatment responses in breast cancer.Results: Expressions of IDO, CD33⁺MDSCs and Foxp3⁺Tregs were correlated with each other. Immunohistochemical double staining revealed that IDO expression in CD33⁺MDSCs was positively correlated with Foxp3⁺Tregs (P < 0.05). CD33⁺MDSCs, Foxp3⁺Tregs, and IDO expression in tumor tissues were associated with advanced clinical stage prior to NCT (P < 0.05). CD33⁺MDSCs, Foxp3⁺Tregs, IDO expression, IDO expression in CD33⁺MDSCs and clinical T3–T4 stage prior to NCT, pathological T3–T4 stage, ER(+), luminal type were correlated with clinical responses of PD+SD (P < 0.05). Multivariate analysis showed that CD33⁺MDSCs, IDO expression, IDO expression in CD33⁺MDSCs, and advanced pathological T stage were risk factors for PD+SD. Focusing on the pCR of NCT, only CD33⁺MDSCs, clinical T3–T4, and N1–N3 stage prior to NCT were associated with no-pCR (P < 0.05). The multivariate analysis showed that advanced clinical T stage and N stage were risk factors for no-pCR. Clinical stage prior to NCT were significantly correlated with progression free survival (P = 0.021), while Foxp3⁺Tregs and clinical T stage were significantly correlated with overall survival (P = 0.022 and P = 0.001, respectively). Foxp3+Treg was significant risk factor for overall survival after adjusting covariates by COX regression.Conclusion: Tumor-infiltrating MDSCs, Tregs, IDO expression and IDO expression in MDSCs were correlated with clinicopathological features, NCT response, and prognosis of breast cancer patients, suggesting that they might be potential markers for clinical outcomes of NCT and help clinical decision-making for improved therapies for breast cancer.

Background: The tumor microenvironment represents an abnormal niche containing numerous factors, such as T cells, dendritic cells (DCs), regulatory T cells (Tregs), and indoleamine 2,3‐dioxygenase (IDO), involved in maintaining immune homeostasis and tolerance. All these factors may influence the choice of therapy and the clinical outcomes.Methods: Flow cytometry was performed to identify CD4+/CD8 + T cells and DCs, and immunohistochemistry was used to evaluate IDO and Forkhead Box P3 (Foxp3) expression; these experiments were performed in order to explore the clinical and prognostic significance of CD4/CD8 + T cells, DCs, Tregs, and IDO expression in gastric carcinoma.Results: Smaller tumor size was correlated with higher expression levels of peripheral CD4 + T cells (P = .003) and CD8 + T cells (P = .002), and lower IDO expression (P = .044) in tumors. Well‐differentiated gastric carcinomas displayed higher peripheral (P = .029) and tumor‐infiltrating CD4 + T cell (P = .009) populations and a higher tumor‐infiltrating DC1/DC2 ratio (P = .048). Gastric cancer in the early T stages exhibited higher populations of peripheral DC2s (P = .044) and a higher tumor‐infiltrating DC1/DC2 ratio (P = .012). Gastric cancer at the N0 stage had lower tumor‐infiltrating DC2s (P = .032) and a higher DC1/DC2 ratio (P = .037). IDO expression was positively correlated with tumor‐infiltrating Foxp3 + Tregs (P < .001) as well as DC2s (P < .001), whereas it was negatively correlated with the tumor‐infiltrating CD4/CD8 + T cell ratio (P = .023). Tumor‐infiltrating Foxp3 + Treg was positively correlated with tumor‐infiltrating DC2s (r² = 0.772; P < .001). At T, N, and TNM stages, the expression levels of peripheral DC2s, tumor‐infiltrating DC1/DC2 ratios, Foxp3 + Tregs, and IDO were significantly correlated with prognosis (P < .05). The T stage and peripheral DC2s were significant risk factors for overall survival.Conclusion: Immunocompetent cells and humoral immune factors, including DC2s, CD4+/CD8 + T cells, Foxp3 + Tregs, and IDO, interact with each other to compose a complex community of tumor immune microenvironment, ultimately affecting tumor progression and survival of gastric cancer.

Indoleamine 2,3-dioxygenase (IDO), which catalyzes the breakdown of the essential amino acid tryptophan into kynurenine, is understood to have a key role in cancer immunotherapy. IDO has also received more attention because of its non-immune functions including regulating angiogenesis. The purpose of this study was to investigate the effects of IDO on microvessel density (MVD), and to explore its prognostic role in breast cancer. We showed IDO expression was positively correlated with MVD labeled by CD105 (MVD-CD105) rather than MVD labeled by CD31 (MVD-CD31) in breast cancer specimens. Both IDO expression and MVD-CD105 level were associated with initial TNM stage, histological grade, and tumor-draining lymph nodes (TDLNs) metastasis in breast cancer. In the prognostic analysis, TDLNs metastasis, an advanced TNM stage (III) and high histological grade (III) significantly predicted shorter survival in univariate analysis. Concentrating on IDO and MVD, the patients with IDO expression or high MVD level had poorer prognosis compared with no IDO expression [P = 0.047 for progress-free survival (PFS)] and low MVD level (P = 0.019 for OS); the patients with IDO expression and high MVD level had a tendency with shorter overall survival when compared with non IDO expression, low MVD level, or both (P = 0.062 for OS). In multivariate analysis, an advanced TNM stage (III) was significantly associated with shorter 5-year survival rate of PFS (HR: 0.126, 95% CI: 0.024–0.669, P = 0.015). In order to verify the phenomenon of IDO promoting angiogenesis, we contained the study in vitro. We detected the expression of IDO mRNA in breast cancer cell lines and measured the concentration of tryptophan and kynurenine in the supernatants of MCF-7 by high performance liquid chromatography. The ratio of Kyn and trp (kyn/trp) was calculated to estimate IDO-enzyme activity. MCF-7 cells, which produce high level of IDO and metabolize tryptophan, promoted human umbilical vein endothelial cells (HUVEC) proliferation significantly in co-culture system. Meanwhile IDO could upregulate the expression of CD105 in HUVEC, which was downregulated after adding IDO inhibitor, 1-methyl-d-trytophan. These results suggest that IDO could promote angiogenesis in breast cancer, providing a novel, potentially effective molecular or gene therapy target for angiogenesis inhibition in the future.

Background: Metabolic syndrome (MetS) play a carcinogenic role in variety of cancers and influence the prognosis of cancer patients both systemically and hormonally. Methods: The data of clinicopathologic features and MetS of 808 gastric cancer patients and 1,146 randomly healthy controls were analyzed retrospectively. Results: Higher TG level, lower HDL-C level and higher hypertension frequency were observed in all gastric cancer patients when compared with healthy controls. While, gastric cancer patients had greater waist circumference only in females. Among three definitions of MetS, the MetS identified by the Chinese Diabetes Society (CDS) was associated with the most significant increasing risk of gastric cancer. Comparing all gastric cancer patients with healthy controls, OR of gastric cancer was enhanced by various individual components of the MetS, including higher TG level, lower HDL-C level, hypertension and diabetes; In male subgroup, OR of gastric cancer was enhanced by higher BMI, hypertension and diabetes; In females, OR of gastric cancer was enhanced by lower HDL-C, hypertension and diabetes. MetS was associated with poor differentiated carcinoma, more advanced pathological T, N stage and TNM stage of gastric cancer. Conclusion: The presence of MetS and its components were increased in gastric cancer, especially in gastric cancer patients with poor differentiation and advanced stage, which implies that metabolic disorder may play an important role in the development of gastric cancer.