The collagenase of the bacterium Clostridium histolyticum does not favor metastasis of breast cancer.

BACKGROUND: Breast cancer is the most common malignancy among women worldwide. As survival rates increase, breast reconstruction and quality of life gain importance. Of all women undergoing breast reconstruction, approximately, 70% opt for silicone implants and 50% of those develop capsular contracture, the most prevalent long-term complication. The collagenase of the bacterium Clostridium histolyticum (CCH) showed promising results in the therapy of capsule contracture; however, its influence on residual cancer cells is unknown. The aim of this study was to investigate whether CCH-treatment negatively impacts breast cancer cells in vitro and in vivo. METHODS: MDA-MB-231 and MCF-7 cells were used in this study. In vitro, we tested the influence of CCH on proliferation, wound healing, migration and cell cycle by MTT-assay, scratch-assay, transwell-migration-assay, and flow cytometry. In vivo, solid tumors were induced in immune-deficient mice. CCH was injected into the tumors and tumor growth and metastasis formation was monitored by caliper measurement, in vivo bioluminescence imaging and histology. Gene expression analysis was performed by microarray including 27,190 genes. RESULTS: CCH-incubation led to a dose-dependent reduction in proliferation for both cell lines, while wound healing was reduced only in MDA-MB-231 cells. No morphological alterations were monitored in cell cycle or apoptosis. In vivo, bioluminescence imaging and histology did not show any evidence of metastasis. Although CCH led to changes in gene expression of breast cancer cells, no relevant alterations in metastasis-related genes were monitored. CONCLUSION: CCH has no impact on tumor growth or metastasis formation in vitro and in vivo. This paves the way for first clinical trials.

Activating Natural Killer Cell Receptors, Selectins, and Inhibitory Siglecs Recognize Ebolavirus Glycoprotein.

Expression of the extensively glycosylated Ebolavirus glycoprotein (EBOV-GP) induces physical alterations of surface molecules and plays a crucial role in viral pathogenicity. Here we investigate the interactions of EBOV-GP with host surface molecules using purified EBOV-GP, EBOV-GP-transfected cell lines, and EBOV-GP-pseudotyped lentiviral particles. Subsequently, we wanted to examine which receptors are involved in this recognition by binding studies to cells transfected with the EBOV-GP as well as to recombinant soluble EBOV-GP. As the viral components can also bind to inhibitory receptors of immune cells (e.g., Siglecs, TIM-1), they can even suppress the activity of immune effector cells. Our data show that natural killer (NK) cell receptors NKp44 and NKp46, selectins (CD62E/P/L), the host factors DC-SIGNR/DC-SIGN, and inhibitory Siglecs function as receptors for EBOV-GP. Our results show also moderate to strong avidity of homing receptors (P-, L-, and E-selectin) and DC-SIGNR/DC-SIGN to purified EBOV-GP, to cells transfected with EBOV-GP, as well as to the envelope of a pseudotyped lentiviral vector carrying the EBOV-GP. The concomitant activation and inhibition of the immune system exemplifies the evolutionary antagonism between the immune system and pathogens. Altogether these interactions with activating and inhibitory receptors result in a reduced NK cell-mediated lysis of EBOV-GP-expressing cells. Modulation of these interactions may provide new strategies for treating infections caused by this virus.