In vitro 2D and 3D cancer models to evaluate compounds that modulate macrophage polarization.

In vitro cancer models that can identify novel immunomodulating compounds are essential. Using a 3D multicellular tumor spheroid (MCTS) model comprising cancer cells, fibroblasts, and macrophages, we tested tumor-associated macrophage (TAM)-inhibiting compounds (CCL2 Ab, CSF1R inhibitor, CSF1R Ab) and TAM-reprograming compounds (poly I:C, CD40 Ab, CD40 ligand) for their effects on monocyte infiltration and polarization in tumor spheroids. For characterization of macrophage polarization, we measured the expression of CD206, CD163, CD86, MHC II, CD40, and CD14 and measured 43 soluble factors in the 3D MCTS cultures. 2D macrophage models were evaluated for comparison. A CSF1R inhibitor prevented infiltration of monocytes into pancreatic cancer spheroids, and macrophages treated with the inhibitor showed decreased expression of M2 markers. Treatment with a CD40 ligand and poly I:C induced M1 macrophage polarization in our models. We propose that these models can be used to improve the drug screening process of anti-cancer immunotherapies targeting macrophages.

Expression and Localization of miR-21 and miR-126 in Mucosal Tissue from Patients with Inflammatory Bowel Disease.

BACKGROUND: microRNAs (miRNAs) are small noncoding RNAs that guide degradation of mRNA and regulate protein expression. miRNA based diagnostic biomarkers for ulcerative colitis (UC) and Crohn's disease (CD) are emerging but information about the cellular localization of many miRNAs is limited and more detailed histologic evaluation of miRNA expression patterns is needed to understand their immunobiological function. METHODS: Formalin-fixed paraffin-embedded colon biopsies from 10 patients with UC and 8 patients with CD together with 9 controls were examined by RT-qPCR and quantitative in situ hybridization (ISH). The cellular expression of miR-21 positive cells was further characterized using immunohistochemical cellular markers. RESULTS: Increased levels of miR-21 and miR-126 were found in UC compared with controls and increased levels of miR-21 were observed in UC compared with CD by both RT-qPCR and quantitative in situ hybridization. miR-126 was localized to endothelial cells and miR-21 to cells in the lamina propria. Multiplex immunohistochemical staining showed miR-21 expression in subsets of CD68 macrophages and CD3 T cells in UC, however, far the majority of the miR-21 positive cells could not be categorized among CD68, CD3, and CD19 cells. CONCLUSIONS: This study shows that miR-126 levels are increased in UC and expressed in endothelial cells. miR-21 is expressed in subsets of monocytes/macrophages and T cells and may work as a potential biomarker to distinguish UC from CD. Quantitative in situ hybridization may be a powerful tool for such analysis as it combines overall expression with validation of cellular origin. Studies in larger cohorts may confirm this for clinical diagnostics.

Urokinase receptor-associated protein (uPARAP) is expressed in connection with malignant as well as benign lesions of the human breast and occurs in specific populations of stromal cells.

The urokinase-type plasminogen activator (uPA) and the uPA receptor (uPAR) are key components in the plasminogen activation system, serving to promote specific events of extracellular matrix degradation in connection with tissue remodeling and cancer invasion. We recently described a new uPAR-associated protein (uPARAP), an internalization receptor that interacts with the pro-uPA:uPAR complex. In our study, we generated a specific polyclonal peptide antibody against human uPARAP and used it for the localization of uPARAP in different breast lesions. The affinity-purified antibodies specifically recognized uPARAP in Western blotting and gave a strong signal in immunohistochemistry. The immunohistochemic localization pattern was found to be identical to that of uPARAP mRNA as determined in parallel by in situ hybridization. uPARAP expression was then studied in both benign and malignant breast lesions. Whereas the normal breast tissue was uPARAP-negative, all benign lesions and ductal carcinoma in situ lesions showed immunoreactivity in fibroblast-like cells and myoepithelial cells associated with the lesion. In invasive carcinoma, uPARAP immunoreactivity was limited to tumor-associated mesenchymal cells. Double immunofluorescence analysis of invasive ductal carcinoma using antibodies against specific cell markers showed that uPARAP was localized in myofibroblasts and macrophages. No malignant cells, no endothelial cells and no vascular smooth muscle cells showed uPARAP immunoreactivity. We conclude that expression of uPARAP is associated with the abnormal breast and that expression appears in myofibroblasts, macrophages and myoepithelium. We suggest that uPARAP is involved in the clearance of the uPA:uPAR complex as well as other possible ligands during benign and malignant tissue remodeling.