BackgroundMammary microcalcifications have a crucial role in breast cancer detection, but the processes that induce their formation are unknown. Moreover, recent studies have described the occurrence of the epithelial–mesenchymal transition (EMT) in breast cancer, but its role is not defined. In this study, we hypothesized that epithelial cells acquire mesenchymal characteristics and become capable of producing breast microcalcifications.MethodsBreast sample biopsies with microcalcifications underwent energy dispersive X-ray microanalysis to better define the elemental composition of the microcalcifications. Breast sample biopsies without microcalcifications were used as controls. The ultrastructural phenotype of breast cells near to calcium deposits was also investigated to verify EMT in relation to breast microcalcifications. The mesenchymal phenotype and tissue mineralization were studied by immunostaining for vimentin, BMP-2, β2-microglobulin, β-catenin and osteopontin (OPN).ResultsThe complex formation of calcium hydroxyapatite was strictly associated with malignant lesions whereas calcium-oxalate is mainly reported in benign lesions. Notably, for the first time, we observed the presence of magnesium-substituted hydroxyapatite, which was frequently noted in breast cancer but never found in benign lesions. Morphological studies demonstrated that epithelial cells with mesenchymal characteristics were significantly increased in infiltrating carcinomas with microcalcifications and in cells with ultrastructural features typical of osteoblasts close to microcalcifications. These data were strengthened by the rate of cells expressing molecules typically involved during physiological mineralization (i.e. BMP-2, OPN) that discriminated infiltrating carcinomas with microcalcifications from those without microcalcifications.ConclusionsWe found significant differences in the elemental composition of calcifications between benign and malignant lesions. Observations of cell phenotype led us to hypothesize that under specific stimuli, mammary cells, which despite retaining a minimal epithelial phenotype (confirmed by cytokeratin expression), may acquire some mesenchymal characteristics transforming themselves into cells with an osteoblast-like phenotype, and are able to contribute to the production of breast microcalcifications.

The Energy Dispersive X-ray (EDX) microanalysis is a technique of elemental analysis associated to electron microscopy based on the generation of characteristic Xrays that reveals the presence of elements present in the specimens. The EDX microanalysis is used in different biomedical fields by many researchers and clinicians. Nevertheless, most of the scientific community is not fully aware of its possible applications. The spectrum of EDX microanalysis contains both semi-qualitative and semi-quantitative information. EDX technique is made useful in the study of drugs, such as in the study of drugs delivery in which the EDX is an important tool to detect nanoparticles (generally, used to improve the therapeutic performance of some chemotherapeutic agents). EDX is also used in the study of environmental pollution and in the characterization of mineral bioaccumulated in the tissues. In conclusion, the EDX can be considered as a useful tool in all works that require element determination, endogenous or exogenous, in the tissue, cell or any other sample.

Recently, interest for the potential impact of consumer-relevant engineered nanoparticles on pregnancy has dramatically increased. This study investigates whether inhaled silver nanoparticles (AgNPs) reach and cross mouse placental barrier and induce adverse effects. Apart from their relevance for the growing use in consumer products and biomedical applications, AgNPs are selected since they can be unequivocally identified in tissues. Pregnant mouse females are exposed during the first 15 days of gestation by nose-only inhalation to a freshly produced aerosol of 18-20 nm AgNPs for either 1 or 4 h, at a particle number concentration of 3.80 × 107 part./cm and at a mass concentration of 640 μg/m³. AgNPs are identified and quantitated in maternal tissues, placentas and foetuses by transmission electron microscopy coupled with energy-dispersive X-ray spectroscopy and single-particle inductively coupled plasma mass spectrometry. Inhalation of AgNPs results in increased number of resorbed foetuses associated with reduced oestrogen plasma levels, in the 4 h/day exposed mothers. Increased expression of pregnancy-relevant inflammatory cytokines is also detected in the placentas of both groups. These results prove that NPs are able to reach and cross the mouse placenta and suggest that precaution should be taken with respect to acute exposure to nanoparticles during pregnancy.

Vascular endothelial growth factor receptor-1 (VEGFR-1) is a tyrosine kinase transmembrane receptor that has also a soluble isoform containing most of the extracellular ligand binding domain (sVEGFR-1). VEGF-A binds to both VEGFR-2 and VEGFR-1, whereas placenta growth factor (PlGF) interacts exclusively with VEGFR-1. In this study we generated an anti-VEGFR-1 mAb (D16F7) by immunizing BALB/C mice with a peptide that we had previously reported to inhibit angiogenesis and endothelial cell migration induced by PlGF. D16F7 did not affect binding of VEGF-A or PlGF to VEGFR-1, thus allowing sVEGFR-1 to act as decoy receptor for these growth factors, but it hampered receptor homodimerization and activation. D16F7 inhibited both the chemotactic response of human endothelial, myelomonocytic and melanoma cells to VEGFR-1 ligands and vasculogenic mimicry by tumor cells. Moreover, D16F7 exerted in vivo antiangiogenic effects in a matrigel plug assay. Importantly, D16F7 inhibited tumor growth and was well tolerated by B6D2F1 mice injected with syngeneic B16F10 melanoma cells. The antitumor effect was associated with melanoma cell apoptosis, vascular abnormalities and decrease of both monocyte/macrophage infiltration and myeloid progenitor mobilization. For all the above, D16F7 may be exploited in the therapy of metastatic melanoma and other tumors or pathological conditions involving VEGFR-1 activation.

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Despite the screening program, breast cancer is the commonest cause of cancer death in women in the industrialized world. In this study, we investigate the correlation among poorly differentiated carcinoma, epithelial to mesenchymal transition (EMT) phenomenon, and expression of NF-kB, Sonic Hedgehog (SHH), K-RAS, and PTX3 in breast cancer in 100 breast biopsies. Samples were classified as follows: 30 benign lesions (BL), 30 ductal infiltrating carcinomas low grade (MLG1), and 40 ductal infiltrating carcinomas high grade (MLG3). Expression of vimentin, CD44, β-catenin, NF-kB, SHH, K-RAS, CD44, and PTX3 was studied by immunohistochemistry. The different rate of cells with vimentin, nuclear β-catenin, and CD44 expression in MLG3 as compared with MLG1 and BL suggested that the process of de-differentiation of breast cancer cells could be related to the EMT. Our results showed a significant increase in NF-kB signal in MLG3 (2.33 ± 0.77) with respect to MLG1 (1.26 ± 0.55) and BL (0.86 ± 0.52). SHH expression appeared low in BL (1.00 ± 0.41) and homogenously widespread in MLG1 (1.23 ± 0.63) and MLG3 (1.56 ± 0.54). An important increase in K-RAS signal was observed in MLG3 compared to that in BL (2.20 ± 0.69 vs 0.82 ± 0.59). As regards PTX3, we observed a strong expression in MLG3 (2.00 ± 0.78) with respect to BL (0.58 ± 0.55) and MLG1 (1.53 ± 0.76). The recurring expression of NF-kB, SHH, K-RAS, and PTX3 in vimentin- and CD44-positive breast cancer cells allows to speculate that breast cells acquire the ability to express these molecules in concomitance to EMT phenomenon.

Pentraxin 3 (PTX3) is a multifunctional glycoprotein regulating inflammatory response, cell proliferation and migration and deposition and remodelling of the extracellular matrix by a variety of cells. In this study, we investigated the possible role of PTX3 in bone homeostasis. To this end, we compared the expression and function of PTX3 in human osteoblasts of osteoporotic, osteoarthritic patients and young subjects not affected by bone diseases. Immunohistochemical analysis performed on bone head biopsies showed a close association between bone health and the number of osteoblasts expressing PTX3. Noteworthy, the proportion of PTX3-positive osteoblasts resulted to be significantly lower in osteoporotic patients compared with both young patients and osteoarthritic patients of the same age. Ex vivo culture of osteoblasts isolated from the three groups of patients confirmed in vivo observation. Specifically, we observed rare runt-related transcription factor 2 (RUNX2) immunopositive osteoblasts expressing PTX3 in cell cultures derived from osteoporotic patients and western blotting analysis showed 80% reduction of PTX3 in the corresponding culture extracts compared with young and osteoarthritic patients. The treatment of human osteoblast primary cultures derived from young patients with anti-PTX3 antibody dramatically affected osteoblast behaviour. Indeed, they lost the morphological and molecular features typical of mature osteoblasts, acquiring fibroblast-like shape and highly decreasing nuclear factor kappa-B ligand (RANKL) and RUNX2 expression. Also, the inhibition of PTX3 negatively affected osteoblast proliferation and their ability to form cell clusters and microhydroxyapatite crystals. Altogether, these results suggest a central role of PTX3 in bone homeostasis showing its involvement in osteoblast proliferation, differentiation and function.

Ellagic acid (EA) is a polyphenolic compound that can be found as a naturally occurring hydrolysis product of ellagitannins in pomegranates, berries, grapes, green tea and nuts. Previous studies have reported the antitumor properties of EA mainly using in vitro models. No data are available about EA influence on bladder cancer cell invasion of the extracellular matrix triggered by vascular endothelial growth factor-A (VEGF-A), an angiogenic factor associated with disease progression and recurrence, and tumor growth in vivo. In this study, we have investigated EA activity against four different human bladder cancer cell lines (i.e., T24, UM-UC-3, 5637 and HT-1376) by in vitro proliferation tests (measuring metabolic and foci forming activity), invasion and chemotactic assays in response to VEGF-A and in vivo preclinical models in nude mice. Results indicate that EA exerts anti-proliferative effects as a single agent and enhances the antitumor activity of mitomycin C, which is commonly used for the treatment of bladder cancer. EA also inhibits tumor invasion and chemotaxis, specifically induced by VEGF-A, and reduces VEGFR-2 expression. Moreover, EA down-regulates the expression of programmed cell death ligand 1 (PD-L1), an immune checkpoint involved in immune escape. EA in vitro activity was confirmed by the results of in vivo studies showing a significant reduction of the growth rate, infiltrative behavior and tumor-associated angiogenesis of human bladder cancer xenografts. In conclusion, these results suggest that EA may have a potential role as an adjunct therapy for bladder cancer.