Treatment of Peritoneal Carcinomatosis by Targeted Delivery of the Radio-Labeled Tumor Homing Peptide 213Bi-DTPA-[F3]2 into the Nucleus of Tumor Cells

BACKGROUND: Alpha-particle emitting isotopes are effective novel tools in cancer therapy, but targeted delivery into tumors is a prerequisite of their application to avoid toxic side effects. Peritoneal carcinomatosis is a widespread dissemination of tumors throughout the peritoneal cavity. As peritoneal carcinomatosis is fatal in most cases, novel therapies are needed. F3 is a tumor homing peptide which is internalized into the nucleus of tumor cells upon binding to nucleolin on the cell surface. Therefore, F3 may be an appropriate carrier for alpha-particle emitting isotopes facilitating selective tumor therapies. PRINCIPAL FINDINGS: A dimer of the vascular tumor homing peptide F3 was chemically coupled to the alpha-emitter (213)Bi ((213)Bi-DTPA-[F3](2)). We found (213)Bi-DTPA-[F3](2) to accumulate in the nucleus of tumor cells in vitro and in intraperitoneally growing tumors in vivo. To study the anti-tumor activity of (213)Bi-DTPA-[F3](2) we treated mice bearing intraperitoneally growing xenograft tumors with (213)Bi-DTPA-[F3](2). In a tumor prevention study between the days 4-14 after inoculation of tumor cells 6x1.85 MBq (50 microCi) of (213)Bi-DTPA-[F3](2) were injected. In a tumor reduction study between the days 16-26 after inoculation of tumor cells 6x1.85 MBq of (213)Bi-DTPA-[F3](2) were injected. The survival time of the animals was increased from 51 to 93.5 days in the prevention study and from 57 days to 78 days in the tumor reduction study. No toxicity of the treatment was observed. In bio-distribution studies we found (213)Bi-DTPA-[F3](2) to accumulate in tumors but only low activities were found in control organs except for the kidneys, where (213)Bi-DTPA-[F3](2) is found due to renal excretion. CONCLUSIONS/SIGNIFICANCE: In conclusion we report that (213)Bi-DTPA-[F3](2) is a novel tool for the targeted delivery of alpha-emitters into the nucleus of tumor cells that effectively controls peritoneal carcinomatosis in preclinical models and may also be useful in oncology

Targeting of Tumor Blood Vessels: A Phage-Displayed Tumor-Homing Peptide Specifically Binds to Matrix Metalloproteinase-2-Processed Collagen IV and Blocks Angiogenesis <i>In vivo</i>

Abstract Proteolytic degradation of the basement membrane by the matrix metalloproteinase-2 and -9 is an essential step in tumor angiogenesis. On proteolytic degradation, cryptic sites in collagen IV are formed, which serve as a migration signal for endothelial cells and are specific for angiogenic blood vessels. The aim of this study was to generate peptides that bind specifically to proteolytically processed collagen IV and to test whether these peptides accumulate in tumor vasculature and are able to block angiogenesis. To obtain such peptides, we performed a combined in vivo and in vitro phage display screen using a recombinant phage-displayed peptide library. We found a phage displaying the peptide sequence TLTYTWS that specifically binds to collagen IV modified by matrix metalloproteinase-2. We then tested the ability of the phage to bind to the vasculature in xenograft tumors and found indeed a significant accumulation of the phage in tumors but not in control organs. The tumor homing of the TLTYTWS phage is specific, as it can be blocked by coinjection chemically synthesized cognate peptide. Moreover, TLTYTWS peptide inhibits angiogenesis in an in vivo assay in a concentration-dependent manner and significantly reduces endothelial differentiation in vitro. In conclusion, we report about a novel tumor-homing peptide that specifically binds to proteolytically processed collagen IV, accumulates in tumors, and blocks angiogenesis. This peptide may be a new useful tool for diagnostic and therapeutic procedures in oncology.(Mol Cancer Res 2009;7(7):1078–85)</jats:p

Intrinsic functional connectivity underlying successful emotion regulation of angry faces

Most of our social interaction is naturally based on emotional information derived from the perception of faces of other people. Negative facial expressions of a counterpart might trigger negative emotions and initiate emotion regulatory efforts to reduce the impact of the received emotional message in a perceiver. Despite the high adaptive value of emotion regulation in social interaction, the neural underpinnings of it are largely unknown. To remedy this, this study investigated individual differences in emotion regulation effectiveness during the reappraisal of angry faces on the underlying functional activity using functional magnetic resonance imaging (fMRI) as well as the underlying functional connectivity using resting-state fMRI. Greater emotion regulation ability was associated with greater functional activity in the ventromedial prefrontal cortex. Furthermore, greater functional coupling between activity in the ventrolateral prefrontal cortex and the amygdala was associated with emotion regulation success. Our findings provide a first link between prefrontal cognitive control and subcortical emotion processing systems during successful emotion regulation in an explicitly social context

Imaging the up’s and down’s of emotion regulation in lifetime depression

Reappraisal is a particularly effective strategy for influencing emotional experiences, specifically for reducing the impact of negative stimuli. Although depression has repeatedly been linked to dysfunctional behavioral and neural emotion regulation, prefrontal and amygdala engagement seems to vary with clinical characteristics and the specific regulation strategy used. Whereas previous neuroimaging research has focused on down-regulating reactions to emotionally evocative scenes, the current study compared up- and down-regulation in response to angry facial expressions in patients with depression and healthy individuals. During the initial viewing of faces, patients with depression showed hypoactivation particularly in areas implicated in emotion generation, i.e., amygdala, insula and putamen. In contrast, up-regulating negative emotions yielded stronger recruitment of core face processing areas and posterior medial frontal cortex in patients than in controls. However, group differences did not extend to resting-state functional connectivity. Recurrent depression was inversely associated with amygdala activation specifically during down-regulation, but differences in medication status may limit the current findings. Despite a pattern of reduced neural emotional reactivity in mainly medicated patients, their ‘successful’ recruitment of the regulation network for up-regulation might point toward an effective use of reappraisal when increasing negative emotions. Future studies need to address how patients might benefit from transferring this ability to adaptive goals, such as improving interpersonal emotion regulation

Noninvasive <i>In Vivo</i> Imaging and Biologic Characterization of Thyroid Tumors by ImmunoPET Targeting of Galectin-3

Abstract The high prevalence of thyroid nodules in the adult population and the relatively low incidence of thyroid cancer make the preoperative identification of malignant lesions challenging. The β-galactoside–binding protein galectin-3 is widely expressed in well-differentiated thyroid carcinomas, but not in normal thyrocytes and benign thyroid nodules. This molecule offers a candidate biomarker to improve thyroid cancer diagnosis. Here we report the development of an immunoPET approach for noninvasive imaging of thyroid cancer. The method employs a 89Zr-labeled mAb to galectin-3, which shows high specificity and binding affinity in vitro. Reliable and specific immunoPET imaging was obtained of thyroid cancer in vivo in murine xenograft models of human thyroid cancer. Our findings provide a method to improve the clinical management of patients with thyroid nodules while reducing unnecessary surgery and social costs. Cancer Res; 76(12); 3583–92. ©2016 AACR.</jats:p

213Bi-anti-EGFR radioimmunoconjugates and X-ray irradiation trigger different cell death pathways in squamous cell carcinoma cells

Introduction: Treatment of patients with squamous cell carcinoma of head and neck is hampered by resistance of tumor cells to irradiation. Additional therapies enhancing the effect of X-ray irradiation may be beneficial. Antibodies targeting EGFR have been shown to improve the efficacy of radiation therapy. Therefore, we analyzed cytotoxicity of Bi-213-anti-EGFR immunoconjugates in combination with X-ray irradiation. Methods: The monoclonal anti-EGFR antibody matuzumab was coupled to CHX-A"-DTPA forming stable complexes with Bi-213. Cytotoxicity of X-ray radiation, of treatment with Bi-213-anti-EGFR monoclonal antibodies (MAb) or of a combined treatment regimen was assayed using cell proliferation and colony formation assays in UD-SCC5 cells. Key proteins of cell-cycle arrest and cell death were examined by Western blot analysis. Cell cycle analysis was performed by flow cytometry. DNA double-strand breaks were detected via gamma H2AX and quantified using Definiens (TM) software. Results: Irradiation with X-rays or treatment with Bi-213-anti-EGFR-MAb resulted in median lethal dose (LD50) values of 12 Gy or 130 kBq/mL, respectively. Treatment with 37 kBq/mL of Bi-213-anti-EGFR-MAb or 2 Gy of X-rays had only little effect on colony formation of UD-SCC5 cells. In contrast, a combined treatment regimen (37 kBq/mL plus 2 Gy) significantly decreased colony formation and enhanced the formation of DNA double-strand breaks. As revealed by flow cytometry, radiation treatments caused accumulation of cells in the GO/G1 phase. Both treatment with Bi-213-anti-EGFR immunoconjugates and application of the combined treatment regimen triggered activation of genes of signaling pathways involved in cell-cycle arrest and induction of apoptosis like p21/Waf, GADD45, Puma and Box, which were only marginally modulated by X-ray irradiation of cells. Conclusions: Bi-213-anti-EGFR-MAb enhances cytotoxicity of X-ray irradiation in UD-SCC5 cells most probably due to effective induction of DNA double-strand breaks. Induction of genes involved in cell-cycle arrest and cell death is almost exclusively due to Bi-213-anti-EGFR-MAb and seems to be independent of p53 function. (C) 2014 Elsevier Inc. All rights reserved

Table S1 from Noninvasive <i>In Vivo</i> Imaging and Biologic Characterization of Thyroid Tumors by ImmunoPET Targeting of Galectin-3

Biodistribution analysis of 89Zr-labelled anti-Gal3 mAb in FRO82-1 tumor bearing mice as selected model.</p