Modulation of E-Cadherin Function through the AmotL2 Isoforms Promotes Ameboid Cell Invasion.

The spread of tumor cells and the formation of distant metastasis remain the main causes of mortality in cancer patients. However, the mechanisms governing the release of cells from micro-environmental constraints remain unclear. E-cadherin negatively controls the invasion of epithelial cells by maintaining cell-cell contacts. Furthermore, the inactivation of E-cadherin triggers invasion in vitro. However, the role of E-cadherin is complex, as metastasizing cells maintain E-cadherin expression, which appears to have a positive role in the survival of tumor cells. In this report, we present a novel mechanism delineating how E-cadherin function is modulated to promote invasion. We have previously shown that E-cadherin is associated with p100AmotL2, which is required for radial actin formation and the transmission of mechanical force. Here, we present evidence that p60AmotL2, which is expressed in invading tumor cells, binds to the p100AmotL2 isoform and uncouples the mechanical constraint of radial actin filaments. We show for the first time that the coupling of E-cadherin to the actin cytoskeleton via p100AmotL2 is directly connected to the nuclear membrane. The expression of p60AmotL2 inactivates this connection and alters the properties of the nuclear lamina, potentiating the invasion of cells into micropores of the extracellular matrix. In summary, we propose that the balance of the two AmotL2 isoforms is important in the modulation of E-cadherin function and that an imbalance of this axis promotes ameboid cell invasion.

Label-free extraction of extracellular vesicles using centrifugal microfluidics.

Extracellular vesicles (EVs) play an important role as active messengers in intercellular communication and distant microenvironment modeling. Increasingly, these EVs are recognized as important biomarkers for clinical diagnostics. However, current isolation methods of EVs are time-consuming and ineffective due to the high diffusive characteristics of nanoparticles coupled with fluid flow instability. Here, we develop a microfluidic CEntrifugal Nanoparticles Separation and Extraction (µCENSE) platform for the rapid and label-free isolation of microvesicles. By utilizing centrifugal microhydrodynamics, we subject the nanosuspensions between 100 nm and 1000 nm to a unique fluid flow resulting in a zonal separation into different outlets for easy post-processing. Our centrifugal platform utilizes a gentle and efficient size-based separation without the requirements of syringe pump and other accessories. Based on our results, we report a high separation efficiency of 90% and an extraction purity of 85% within a single platform. Importantly, we demonstrate high EV extraction using a table top centrifuge within a short duration of eight minutes. The simple processes and the small volume requirement further enhance the utility of the platform. With this platform, it serves as a potential for liquid biopsy extraction and point-of-care diagnostics.

[Dynamic expression of matrix metalloproteinase-2, membrane type-matrix metalloproteinase-2 in experimental hepatic fibrosis and its reversal in rat].

OBJECTIVE: To investigate the expression dynamics and significance of matrix metalloproteinase-2 (MMP-2) membrane type-matrix metalloproteinase-2 (MT-MMP-2) in hepatic fibrosis and its reversal counterpart. METHODS: An experimental CCl4 induced hepatic fibrosis rat model was established by intraperitoneal administration of carbon tetrachloride for 2, 4, 6, 8, 10 weeks, and normal rats were used as a control group. The immunohistochemical methods and in situ hybridization were used to detect MMP-2,MT-MMP-2 mRNA and related antigens in the liver. RESULTS: MMP-2,MT-MMP-2 mRNA and related antigens were expressed in mesenchymal cells and parts of hepatocytes besides active pathological changes, especially in the fibrous septum and portal area. Expression of MMP-2,MT-MMP-2 mRNA and related antigens were increased in hepatic fibrosis and decreased gradually in its reversal counterpart. CONCLUSION: This study suggested that mesenchymal cells are the main cellular origins of MMPs. The levels of MMP-2 and MT-MMP-2 antigens and gene expression were closely related to hepatic fibrosis. MMP-2 and MT-MMP-2 may play important roles in hepatic fibrosis and its reversal counterpart.