Matrix Degradation Assay to Measure the Ability of Tumor Cells to Degrade Extracellular Matrix

Divergent synthesis of fractionated Cannabis sativa extract led to multiple cannabinoids C-&O-glycosides with anti-proliferative/anti-metastatic properties

Here, we present an interesting, previously unreported method for fractionating a particular class of cannabinoids from the crude leaf extract of Cannabis sativa using HP-20 resins. In this study, we report a novel method of divergent synthesis of fractionated Cannabis sativa extract, which allows the generation of multiple cannabinoids C- and O-glycosides which react with the glycosyl donor 2,3,4,6-tetra-O-acetyl-d-mannosyl trichloroacetimidate (TAMTA) to create eight C- and O-β-d-cannabinoids glycosides (COCG), which are separated by HPLC and whose structures are characterized by 1D, 2D NMR, and mass spectrometry. These glycosides exhibit improved anti-proliferative and anti-metastatic effects against numerous cancer cell lines in vitro and are more water-soluble and stable than their parent cannabinoids. The in vitro testing of the pure cannabinoids (1-4) and their C- & O-glycosides (1a-4a) and 1b-4b exhibited anti-proliferative and anti-metastatic activities against a panel of eight human cancer cell lines in contrast to their respective parent molecules. Different cancer cell lines' IC50 values varied significantly when their cell viability was compared. In addition to the others, compounds 2a, 3a, 4a, and 2b, 3b were highly potent, with IC50values ranging from 0.74 µM (3a) to 51.40 µM (4a).Although2a(1.42 µM) and3a(0.74 µM) exhibited lower IC50values in the MiaPaca-2 cell line than4a(2.58 µM). But, in addition to the comparable anti-clonogenic activity of4ain MiaPaca-2 and Panc-1 cells, it manifested remarkable anti-invasive activity than either 2a or 3a.In contrast to 2a, 2b, 3a, and 3b and their respective parent compounds,4ahad substantial anti-invasive/anti-metastatic capabilities and possessed anti-proliferative activity.The effects of 4a treatment on MiaPaca-2 and Panc-1 cells include a dose-dependent increase in the expression of E-cadherin and a significant decrease in the expression of Zeb-1, Vimentin, and Snail1. Our results demonstrate that divergent synthesis of fractionated Cannabis sativa extract is a feasible and efficient strategy to produce a library of novel cannabinoid glycosides with improved pharmacological properties and potential anticancer benefits.

Fibroblast activation protein drives tumor metastasis via a protease-independent role in invadopodia stabilization

During metastasis, tumor cells invade through the basement membrane and intravasate into blood vessels and then extravasate into distant organs to establish metastases. Here, we report a critical role of a transmembrane serine protease fibroblast activation protein (FAP) in tumor metastasis. Expression of FAP and TWIST1, a metastasis driver, is significantly correlated in several types of human carcinomas, and FAP is required for TWIST1-induced breast cancer metastasis to the lung. Mechanistically, FAP is localized at invadopodia and required for invadopodia-mediated extracellular matrix degradation independent of its proteolytic activity. Live cell imaging shows that association of invadopodia precursors with FAP at the cell membrane promotes the stabilization and growth of invadopodia precursors into mature invadopodia. Together, our study identified FAP as a functional target of TWIST1 in driving tumor metastasis via promoting invadopodia-mediated matrix degradation and uncovered a proteolytic activity-independent role of FAP in stabilizing invadopodia precursors for maturation.

Collagen-alginate 3D microscaffolds for studying cellular migration

Metastasis is one of the major causes for cancer mortality. Its early steps comprise of invasion of basement membrane and migration. Thus, it is hypothesized that a platform, that allows quantification and grading of migration capability of cells can potentially be used for predicting metastatic potential. Two-dimensional (2D) models have been rendered inadequate for modelling in-vivo microenvironment due to various reasons. To attenuate homogeneity observed in 2D, three-dimensional (3D) platforms supplemented with bioinspired components have been designed. Unfortunately, till date there are no simple models to capture the migration of cells in 3D along with quantification of the process. In this study, we report an alginate-collagen based 3D model system, which can predict the migratory property of the cells within 72 h. The micron size of the scaffold enabled faster readout and the optimum pore-size provided conducive cellular growth environment. The platform's ability to allow observation of cellular migration was validated by encapsulating cells with transiently upregulated matrix metalloprotease 9 (MMP9), which has been reported to play a significant role in migration of cells during metastasis. The readout for migration was clustering of cells in the microscaffolds detected in a short span of 48 h. The observed clustering in MMP9 upregulated cells was validated by observing changes in the epithelial-mesenchymal transition (EMT) markers. Thus, this simple 3D platform can be used to study migration and predict the metastatic potential of cells.

TEM1 up-regulates MMP-2 and promotes ECM remodeling for facilitating invasion and migration of uterine sarcoma

OBJECTIVES

To explore the correlation between tumor endothelial marker 1 (TEM1) and matrix metalloproteinase 2 (MMP-2) in uterine sarcoma and their roles in the progression of uterine sarcoma.

METHODS

Uterine leiomyosarcoma (uLMS, n = 25) and uterine leiomyoma (n = 25) specimens were collected from a total of 50 patients. Immunohistochemistry assay was conducted to determine the expression of TEM1, MMP-2 and MMP-9. TEM1 over expression (hTEM1) and low expression (shRNA-TEM1) MES-SA cell lines were established as in vitro uterine sarcoma models. MMP-2 mRNA, protein expression and enzymatic activity were verified using qPCR, Western blot and gelatin zymography respectively. MMP-2 expression was downregulated using MMP-2 siRNA in hTEM1 MES-SA cells to better study the role of MMP-2. The invasive and migratory capacities of hTEM1, shRNA-TEM1, and hTEM1 treated with MMP-2 siRNA MES-SA cells were determined using transwell assays. Extracellular matrix (ECM) remodeling mediated by TEM1 was examined using cell-ECM adhesion and fluorescent gelatin-ECM degradation assays. The immunofluorescence of F-actin was examined to analyze the formation of invadopodia. Subcutaneous and intraperitoneal xenografts were established to validate the role of TEM1 in promoting uterine sarcoma metastasis.

RESULTS

TEM1 and MMP-2 were expressed in 92% (n = 23) and 88% (n = 22) of uterine leiomyosarcoma specimens, respectively. Both TEM1 and MMP-2 were highly expressed in 100% (n = 17) of high stage (III-IV) uterine leiomyosarcoma specimens. In addition, TEM1 expression was positively correlated with MMP-2 expression in uterine leiomyosarcoma. The successful establishment of in vitro uterine sarcoma models was confirmed with qPCR and Western blotting tests. TEM1 promoted the invasion and metastasis of uterine sarcoma in vivo and in vitro. MMP-2 expression and activity were up-regulated in hTEM1 cells but down-regulated in shRNA-TEM1 cells. Importantly, MMP-2 knockdown impaired the invasive and migratory capacity of hTEM1 cells. TEM1 promoted ECM remodeling by increasing cell-ECM adhesion and ECM degradation. TEM1 overexpression also induced the formation of invadopodia.

CONCLUSION

TEM1 was co-expressed and positively correlated with MMP-2 in uterine leiomyosarcoma specimens. In addition, both TEM1 and MMP-2 were associated with tumor development. TEM1 promoted uterine sarcoma progression by regulating MMP-2 activity and ECM remodeling.

Analysis of Polycomb Epigenetic Marks in HeLa Spheroids

Biochemical composition of the nucleus affects both its physical properties and its morphology. In recent years, several studies demonstrated the formation of f-actin in the nuclei. These filaments intermingle with the chromatin fibers underlying the crucial role of the mechanical force in chromatin remodeling, being thus involved in transcription, differentiation, replication, and DNA repair. Given the suggested role of Ezh2 in the cross-talk between f-actin and chromatin, we describe here how to obtain HeLa cell spheroids and a method to perform immunofluorescence analysis of nuclear epigenetic marks in a 3D cell culture system.

Current methods for studying metastatic potential of tumor cells

Cell migration and invasiveness significantly contribute to desirable physiological processes, such as wound healing or embryogenesis, as well as to serious pathological processes such as the spread of cancer cells to form tumor metastasis. The availability of appropriate methods for studying these processes is essential for understanding the molecular basis of cancer metastasis and for identifying suitable therapeutic targets for anti-metastatic treatment. This review summarizes the current status of these methods: In vitro methods for studying cell migration involve two-dimensional (2D) assays (wound-healing/scratch assay), and methods based on chemotaxis (the Dunn chamber). The analysis of both cell migration and invasiveness in vitro require more complex systems based on the Boyden chamber principle (Transwell migration/invasive test, xCELLigence system), or microfluidic devices with three-dimensional (3D) microscopy visualization. 3D culture techniques are rapidly becoming routine and involve multicellular spheroid invasion assays or array chip-based, spherical approaches, multi-layer/multi-zone culture, or organoid non-spherical models, including multi-organ microfluidic chips. The in vivo methods are mostly based on mice, allowing genetically engineered mice models and transplant models (syngeneic mice, cell line-derived xenografts and patient-derived xenografts including humanized mice models). These methods currently represent a solid basis for the state-of-the art research that is focused on understanding metastatic fundamentals as well as the development of targeted anti-metastatic therapies, and stratified treatment in oncology.