MicroRNAs in the Tumor Microenvironment.

The tumor microenvironment (TME) is decisive for the eradication or survival of any tumor mass. Moreover, it plays a pivotal role for metastasis and for providing the metastatic niche. The TME offers special physiological conditions and is composed of, for example, surrounding blood vessels, the extracellular matrix (ECM), diverse signaling molecules, exosomes and several cell types including, but not being limited to, infiltrated immune cells, cancer-associated endothelial cells (CAEs), and cancer-associated fibroblasts (CAFs). These cells can additionally and significantly contribute to tumor and metastasis progression, especially also by acting via their own deregulated micro (mi) RNA expression or activity. Thus, miRNAs are essential players in the crosstalk between cancer cells and the TME. MiRNAs are small non-coding (nc) RNAs that typically inhibit translation and stability of messenger (m) RNAs, thus being able to regulate several cell functions including proliferation, migration, differentiation, survival, invasion, and several steps of the metastatic cascade. The dynamic interplay between miRNAs in different cell types or organelles such as exosomes, ECM macromolecules, and the TME plays critical roles in many aspects of cancer development. This chapter aims to give an overview on the multiple contributions of miRNAs as players within the TME, to summarize the role of miRNAs in the crosstalk between different cell populations found within the TME, and to illustrate how they act on tumorigenesis and the behavior of cells in the TME context. Lastly, the potential clinical utility of miRNAs for cancer therapy is discussed.

Onchocerciasis control in the Democratic Republic of Congo (DRC): challenges in a post-war environment.

OBJECTIVE: To evaluate onchocerciasis control activities in the Democratic Republic of Congo (DRC) in the first 12 years of community-directed treatment with ivermectin (CDTI). METHODS: Data from the National Programme for Onchocerciasis (NPO) provided by the National Onchocerciasis Task Force (NOTF) through the annual reports of the 21 CDTI projects for the years 2001-2012 were reviewed retrospectively. A hypothetical-inputs-process-outputs-outcomes table was constructed. RESULTS: Community-directed treatment with ivermectin expanded from 1968 communities in 2001 to 39 100 communities by 2012 while the number of community-directed distributors (CDD) and health workers (HW) multiplied. By 2012, there were ratios of 1 CDD per 262 persons and 1 HW per 2318 persons at risk. More than 80% of the funding came from the fiduciary funds of the African Programme for Onchocerciasis Control. The cost of treatment per person treated fell from US$ 1.1 in 2001 to US$ 0.1 in 2012. The therapeutic coverage increased from 2.7% (2001) to 74.2% (2012); the geographical coverage, from 4.7% (2001) to 93.9% (2012). Geographical coverage fell in 2005 due to deaths in loiasis co-endemic areas, and the therapeutic coverage fell in 2008 due to insecurity. CONCLUSIONS: Challenges to CDTI in DRC have been serious adverse reactions to ivermectin in loiasis co-endemic areas and political conflict. Targets for personnel or therapeutic and geographical coverages were not met. Longer term funding and renewed efforts are required to achieve control and elimination of onchocerciasis in DRC.

Immune Regulation by Cytosolic DNA Sensors in the Tumor Microenvironment.

cGAS and AIM2 are CDSs that are activated in the presence of cytosolic dsDNA and are expressed in various cell types, including immune and tumor cells. The recognition of tumor-derived dsDNA by CDSs in the cytosol of tumor-infiltrating dendritic cells (TIDCs) activates the innate and acquired immunity, thereby enhancing anti-tumor immune responses. STING is the downstream signaling effector of cGAS that induces type I interferon (IFN) signaling. Owing to their ability to activate TIDCs, STING agonists have been intratumorally injected in several clinical trials to enhance the anti-tumor immune response elicited by immune checkpoint antibodies. However, they have shown minimal effect, suggesting the importance of optimizing the dose and route of administration for STING agonists and deciphering other immune pathways that contribute to anti-tumor immune responses. Recent studies have revealed that AIM2 activity induces pro-tumor growth through multiple parallel pathways, including inhibition of STING-type I IFN signaling. Thus, AIM2 could be a potential molecular target for cancer immunotherapies. This review summarizes the current research on the roles of cGAS, STING, and AIM2 in immune cells and tumor cells in the tumor microenvironment and discusses the future prospects of anti-tumor treatment approaches based on these molecules.

High level of mature tumor-infiltrating dendritic cells predicts progression to muscle invasion in bladder cancer.

A prognostic value for tumor-associated macrophages (TAMs) and tumor-infiltrating dendritic cells (TIDCs) has been reported in many human cancers. The objective of this study is to determine the prognostic value of CD83(+) mature TIDCs and CD68(+) TAMs in non-muscle-invasive bladder cancer at first diagnosis. Immunohistochemistry staining was performed with anti-CD68 and anti-CD83 monoclonal antibodies on tissue sections from 93 formalin-fixed, paraffin-embedded tissue blocks from pTa and pT1 bladder tumors. A scoring index based on the average density of observed positive cells in the papillary axis, the stroma, lymphoid aggregates, and into tumor foci was calculated for each patient. Comparison of baseline characteristics with marker levels was done using Pearson χ(2) or Fisher exact test. Kaplan-Meier analyses and Cox regression models were fitted to evaluate the prognostic value of TIDCs and TAMs. The absence of both CD68(+) TAMs and CD83(+) TIDCs was associated with tumor recurrence. The presence of TIDCs was associated with a significant risk of progression to muscle-invasive cancer (hazard ratio, 8.253; P = .0179). Patients were risk stratified using age and TIDC score. Patients 70 years or older with a high score of TIDCs had a 56% progression-free survival after 6 years compared with 94% for patients younger than 70 years with a low score of TIDCs. None of 20 patients with a low score of TAMs progressed. These data indicate that the presence of mature TIDCs and possibly TAMs may help risk-stratify patients at the time of first diagnosis of non-muscle-invasive bladder cancer and may be useful in tailoring follow-up and treatment strategies.

A preliminary study of the immunotherapy of dendritic cells transfected with mRNA of gastric cancer cells in carried-tumor mice and its exosomes / 中国免疫学杂志

Objective:Our previous result showed unravel the functional status of DC in the tissue of gastric cancer (GC) and precancerous lesions, and probed into the possibility of preventing solid carcinoma such as GC.Methods:In the experiment of immunotherapy for the tumor-bearing mice,treated by DC sensitized by mRNA of gastric acncer cells.Results:The indices such as the production rate of ascites of mice(75%),the metastasis rate of tumor(25%),the survival rate of animals (75%) and the average weight of trmor(2.04?0.33 g)showed that the condition of the mice treated by DC was better than that in the control group(P