No abstract

Purpose: Near-IR fluorescence imaging has great potential for noninvasive in vivo imaging of tumors. In this study, we show the preferential uptake and retention of two hepatamethine cyanine dyes, IR-783 and MHI-148, in tumor cells and tissues.Experimental Design: IR-783 and MHI-148 were investigated for their ability to accumulate in human cancer cells, tumor xenografts, and spontaneous mouse tumors in transgenic animals. Time-and concentration-dependent dye uptake and retention in normal and cancer cells and tissues were compared, and subcellular localization of the dyes and mechanisms of the dye uptake and retention in tumor cells were evaluated using organelle-specific tracking dyes and bromosulfophthalein, a competitive inhibitor of organic anion transporting peptides. These dyes were used to detect human cancer metastases in a mouse model and differentiate cancer cells from normal cells in blood.Results: These near-IR hepatamethine cyanine dyes were retained in cancer cells but not normal cells, in tumor xenografts, and in spontaneous tumors in transgenic mice. They can be used to detect cancer metastasis and cancer cells in blood with a high degree of sensitivity. The dyes were found to concentrate in the mitochondria and lysosomes of cancer cells, probably through organic anion transporting peptides, because the dye uptake and retention in cancer cells can be blocked completely by bromosulfophthalein. These dyes, when injected to mice, did not cause systemic toxicity.Conclusions: These two heptamethine cyanine dyes are promising imaging agents for human cancers and can be further exploited to improve cancer detection, prognosis, and treatment.

IL-7, a powerful lymphopoietic cytokine, is elevated in rheumatoid arthritis (RA) and known to induce bone loss when administered in vivo. IL-7 has been suggested to induce bone loss, in part, by stimulating the proliferation of B220 ؉ cells, a population capable of acting as early osteoclast (OC) precursors. However, the mechanism by which IL-7 leads to differentiation of precursors into mature OCs remains unknown. We previously reported that, in vitro, IL-7 up-regulated T cell cytokines including receptor activator of nuclear factor B ligand (RANKL). To demonstrate the importance of T cells to the bone-wasting effect of IL-7 in vivo, we have now examined IL-7-induced bone loss in T cell-deficient nude mice. We show that T cell-replete mice undergo significant osteoclastic bone loss after IL-7 administration, concurrent with induction of RANKL and tumor necrosis factor ␣ (TNF-␣) secretion by splenic T cells. In contrast, nude mice were resistant to IL-7-induced bone loss and showed no detectable increase in either RANKL or TNF-␣, despite an up-regulation of B220 ؉ cells. Importantly, T cell adoptive transfer into nude mice restored IL-7-induced bone loss, and RANKL and TNF-␣ secretion, demonstrating that T cells are essential mediators of IL-7-induced bone loss in vivo.osteoclast ͉ cytokines ͉ osteoporosis ͉ rheumatoid arthritis

Estrogen (E) deficiency leads to an expansion of the pool of tumor necrosis factor (TNF)-producing T cells through an IFN-␥-dependent pathway that results in increased levels of the osteoclastogenic cytokine TNF in the bone marrow. Disregulated IFN-␥ production is instrumental for the bone loss induced by ovariectomy (ovx), but the responsible mechanism is unknown. We now show that mice with T cell-specific blockade of type ␤ transforming growth factor (TGF␤) signaling are completely insensitive to the bone-sparing effect of E. This phenotype results from a failure of E to repress IFN-␥ production, which, in turn, leads to increased T cell activation and T cell TNF production. Furthermore, ovx blunts TGF␤ levels in the bone marrow, and overexpression of TGF␤ in vivo prevents ovx-induced bone loss. These findings demonstrate that E prevents bone loss through a TGF␤-dependent mechanism, and that TGF␤ signaling in T cells preserves bone homeostasis by blunting T cell activation. Thus, stimulation of TGF␤ production in the bone marrow is a critical ''upstream'' mechanism by which E prevents bone loss, and enhancement of TGF␤ levels in vivo may constitute a previously undescribed therapeutic approach for preventing bone loss.A lthough multiple genotropic and nongenotropic effects contribute to explain how estrogen (E) controls bone remodeling (1, 2), most of the bone-sparing activity exerted by E occurs through modulation of bone cell life span and decreased cytokine-driven osteoclastogenesis (3, 4). Among the factors that up-regulate osteoclast (OC) formation and lead to bone loss in estroprevic humans and rodents is tumor necrosis factor (TNF) ␣ (5). This E-regulated cytokine promotes osteoclastogenesis by augmenting the production of receptor activator of nuclear factor-B ligand (RANKL) (1), the nonredundant cytokine responsible for OC development (6) and by increasing the responsiveness of maturing OCs to this factor (7-9). Furthermore, TNF stimulates the production of other cytokines known to be implicated in the pathogenesis of ovariectomy (ovx)-induced bone loss, such as IL-1, IL-6, IL-7, and macrophage colony-stimulated factor (1, 10).ovx increases TNF levels in the bone marrow (BM) via an expansion of the pool of TNF-producing T cells (7, 11) induced by a complex mechanism driven by IFN-␥ (12). This cytokine augments antigen (Ag) presentation by enhancing MHCII expression on BM macrophages (BMMs), through induction of class II transactivator (CIITA) expression (13). Up-regulation of Ag presentation results, in turn, in increased T cell activation. Thus, upregulation of IFN-␥ production induced by ovx leads to increased T cell proliferation and life span, a phenomenon that results in an increase in both the total number of T cells and the pool of TNF-producing T cells (12). T cell-produced TNF plays a pivotal role in the mechanism of ovx-induced bone loss, as demonstrated by the failure of ovx to induce bone loss in T cell-deficient nude mice and by the ability to reconstitute with WT T cells, but not TNFϪ͞Ϫ ...

Overcoming resistance to chemotherapy is a major and unmet medical challenge in the treatment of pancreatic cancer. Poor drug delivery due to stromal barriers in the tumor microenvironment and aggressive tumor biology are additional impediments toward a more successful treatment of pancreatic cancer. In attempts to address these challenges, we developed IGF1 receptor (IGF1R)-directed, multi-functional theranostic nanoparticles for targeted delivery of therapeutic agents into IGF1R-expressing drug-resistant tumor cells and tumor-associated stromal cells. These nanoparticles were prepared by conjugating recombinant human IGF1 to magnetic iron oxide nanoparticles (IONPs) carrying the anthracycline doxorubicin (Dox) as the chemotherapeutic payload. Intravenously administered IGF1-IONPs exhibited excellent tumor targeting and penetration in an orthotopic patient-derived xenograft (PDX) model of pancreatic cancer featuring enriched tumor stroma and heterogeneous cancer cells. IGF1R-targeted therapy using the theranostic IGF1-IONP-Dox significantly inhibited the growth of pancreatic PDX tumors. The effects of the intratumoral nanoparticle delivery and therapeutic responses in the orthotopic pancreatic PDX tumors could be detected by magnetic resonance imaging (MRI) with IONP-induced contrasts. Histological analysis showed that IGF1R-targeted delivery of Dox significantly inhibited cell proliferation and induced apoptotic cell death of pancreatic cancer cells. Therefore, further development of IGF1R-targeted theranostic IONPs and MRI-guided cancer therapy as a precision nanomedicine may provide the basis for more effective treatment of pancreatic cancer.

Surface properties, as well as inherent physicochemical properties, of the engineered nanomaterials play important roles in their interactions with the biological systems, which eventually affect their efficiency in diagnostic and therapeutic applications. Here we report a new class MRI contrast agent based on milk casein protein coated iron oxide nanoparticles (CNIOs) with a core size of 15 nm and hydrodynamic diameter ~30 nm. These CNIOs exhibited excellent water-solubility, colloidal stability, and biocompatibility. Importantly, CNIOs exhibited prominent T2 enhancing capability with a transverse relaxivity r2 of 273 mM−1s−1 at 3 Tesla. The transverse relaxivity is ~2.5-fold higher than that of iron oxide nanoparticles with the same core but an amphiphilic polymer coating. CNIOs showed pH-responsive properties, formed loose and soluble aggregates near the pI (pH~4.0). The aggregates could be dissociated reversibly when the solution pH was adjusted away from the pI. The transverse relaxation property and MRI contrast enhancing effect of CNIOs remained unchanged in the pH range of 2.0 to 8.0. Further functionalization of CNIOs can be achieved via surface modification of the protein coating. Bio-affinitive ligands, such as a single chain fragment from the antibody of epidermal growth factor receptor (ScFvEGFR), could be readily conjugated onto the protein coating, enabling specific targeting to MDA-MB-231 breast cancer cells over-expressing EGFR. T2-weighted MRI of mice intravenously administered with CNIOs demonstrated strong contrast enhancement in the liver and spleen. These favorable properties suggest CNIOs as a class of biomarker targeted magnetic nanoparticles for MRI contrast enhancement and related biomedical applications.

No abstract

LIV-1, a zinc transporter, is an effector molecule downstream from soluble growth factors. This protein has been shown to promote epithelial-to-mesenchymal transition (EMT) in human pancreatic, breast, and prostate cancer cells. Despite the implication of LIV-1 in cancer growth and metastasis, there has been no study to determine the role of LIV-1 in prostate cancer progression. Moreover, there was no clear delineation of the molecular mechanism underlying LIV-1 function in cancer cells. In the present communication, we found increased LIV-1 expression in benign, PIN, primary and bone metastatic human prostate cancer. We characterized the mechanism by which LIV-1 drives human prostate cancer EMT in an androgen-refractory prostate cancer cells (ARCaP) prostate cancer bone metastasis model. LIV-1, when overexpressed in ARCaPE (derivative cells of ARCaP with epithelial phenotype) cells, promoted EMT irreversibly. LIV-1 overexpressed ARCaPE cells had elevated levels of HB-EGF and matrix metalloproteinase (MMP) 2 and MMP 9 proteolytic enzyme activities, without affecting intracellular zinc concentration. The activation of MMPs resulted in the shedding of heparin binding-epidermal growth factor (HB-EGF) from ARCaPE cells that elicited constitutive epidermal growth factor receptor (EGFR) phosphorylation and its downstream extracellular signal regulated kinase (ERK) signaling. These results suggest that LIV-1 is involved in prostate cancer progression as an intracellular target of growth factor receptor signaling which promoted EMT and cancer metastasis. LIV-1 could be an attractive therapeutic target for the eradication of pre-existing human prostate cancer and bone and soft tissue metastases.