Directed cancer cell migration induced by the environmental signals is a critical process in cancer metastasis. Cancer cells are exposed to complex chemical and mechanical signals stimulating directed migration in the tumor microenvironment, where the physical nature is highly complex. It is still barely understood how cells sense and process the complex environmental signals through the complex intercellular signaling networks to execute the cell responses. This study explores the migratory response of cancer cells under a single and combined signal. The driving hypothesis is that the cell innate capability constraints the signal stimulations physically in inducing directed cell migration. We assess the hypothesis by engineering the microenvironment in the microfluidic platform, exposing a single or combined signal environment. The combined signal environment is established by 1) two different chemoattractants (TGF-β1 and EGF) and 2) the convection-driven signal environment (TGF-β1 and interstitial flow). The results show that the performance of cancer cell directed migration is physically constrained when the environmental stimulation meets the cell’s innate physical limit. We illustrate the results in a physical and quantitative manner. This approach provides a novel insight to understand the cellular process and eventually enables to predict the cellular response under the complex environmental signals. <br>

Cancer metastasis is a highly complex process and is of great clinical importance since majority of cancer related mortality is associated with metastatic disease rather than primary tumor. The fact that cancer metastasis can develop years or even decades after primary tumor diagnosis, makes this process even more complex and therefore its understanding is of vital importance. Cervical cancer (CxC) is one of the most commonly diagnosed and cause of death among gynecologic cancers worldwide. In this chapter, our aim is to provide a broad overview of risk factors, modes of metastasis and major molecular factors and signaling pathways involved in the progression and metastasis of CxC. The understanding of these factors will enhance the knowledge of CxC pathogenesis and targeting these pathways would help combat against CxC and its metastasis.

Lymphatic metastasis in breast cancer (BC) is one of the most important prognostic factors for patient survival. The escaped tumor cells reach distant vital organs and their unopposed expansion in these organs may cause mortality to patient. Tumor cells are transported to lymph node (LN) exclusively by tumor lymphatic vessels (LV). Increased tumor lymphangiogenesis, i.e., the formation of new LV is currently thought to be promoted by soluble factors such as VEGF-C and –D that activate VEGFR-3 expressed in lymphatic endothelial cells (LEC). These factors are secreted by malignant, tumor-infiltrating immune and stromal cells and create a favorable environment for formation of new vessels. However, emerging evidence suggests that tumor lymphangiogenesis is also promoted by Myeloid-derived Lymphatic Endothelial Cell Progenitors (M-LECP). We recently showed that M-LECP are abundant in mouse and human breast tumors and that their density strongly correlates with both lymphatic formation and nodal metastasis. Characterization of M-LECP showed that nearly all these cells express typical markers of the M2-type of macrophages such as CD163, CD204, and CD209. These cells are consider to be strongly immunosuppressive as exemplified by their inhibition of mobilization, activation, and survival of the key defenders against cancer cells, cytotoxic CD8+ T lymphocytes. Here, we compare the in vitro differentiation of M-LECP derived from bone marrow (BM) myeloid precursors primed with CSF-1 followed by secondary stimulants such as LPS, an immunomodulatory ligand for TLR4, and IL-4, IL-13, and IL-10 downstream targets of this receptor that are known to promote M2-macrophage development. Expression of these stimulants was analyzed by qPCR, flow cytometry, and ELISA during M-LECP differentiation. Our study describes the expression and functionality of these Th2 cytokines and their receptors during M-LECP differentiation. We found that each of the Th2 pathways singularly promotes M-LECP differentiation but there is an absent additive effect. We also found that IL-10 but no other Th2 cytokines is upregulated along with its receptor and contributes to the expression of the lymphatic properties similarly to LPS. To our knowledge, the role of IL-10 in development of lymphatic phenotype through differentiation of M-LECP has not been reported previously. Lastly, we show recruitment of M-LECP in a mouse BC model and the co-expression of the Th2 cytokine receptors in these cells. These studies have a potential to identify new regulators of M-LECP production in the bone marrow that could serve as biomarkers and targets for inhibiting tumor lymphatic formation, and by extension, lymph node metastasis.

No description available.

Digital image processing is widely used in the field of time-lapse microscopy and biological research to provide statistical data of cellular dynamics. The data can provide more comprehensive understanding of the molecular phenomenon. Further, digital image processing enables rapid and consistent quantification of qualitative observations. The image processing model examined here provides a study to identify structures called retraction fibers (RFs) that are formed during epithelial-mesenchymal transition (EMT) [1], an important developmental process which also occurs during cancer metastasis. Quantifying RF formation is an important task for biologists studying cellular regulation of EMT. This thesis work uses digital image processing and computer vision algorithms to detect and track each RF in image sequences of cells undergoing EMT that are captured using time-lapse microscopy. The algorithms isolate the RFs with reasonable precision. Statistical information is generated about these automatically detected RFs, such as the number formed during a particular time window, lifetime of each, and their geometric dimension. This information can in turn be used by biologists to quantitatively measure the extent of EMT under different test conditions. Biologists feel that the information thus obtained may help clarify the molecular interactions of cell migration and will aid in developing methods of preventing cancer metastasis. Experimental results show that this methodology has significant potential in helping biologists determine RF behavior during EMT.

The extra-cellular microenvironment has a fundamental role in tumor growth and progression, strongly affecting the migration strategies adopted by single cancer cells during metastatic invasion. In this study, we use a novel microfluidic device to investigate the ability of mesenchymal and epithelial breast tumor cells to fluidize and migrate through narrowing microstructures upon chemoattractant stimulation. We compare the migration behavior of two mesenchymal breast cancer cell lines and one epithelial cell line, and find that the epithelial cells are able to migrate through the narrowest microconstrictions as the more invasive mesenchymal cells. In addition, we demonstrate that migration of epithelial cells through a highly compressive environment can occur in absence of a chemoattractive stimulus, thus evidencing that they are just as prone to react to mechanical cues as invasive cells

The traditional picture of tissues, where they are treated as liquids defined by properties such as surface tension or viscosity has been redefined during the last few decades by the more fundamental question: under which conditions do tissues display liquid-like or solid-like behaviour? As a result, basic concepts arising from the treatment of tissues as solid matter, such as cellular jamming and glassy tissues, have shifted into the current focus of biophysical research. Here, we review recent works examining the phase states of tissue with an emphasis on jamming transitions in cancer. When metastasis occurs, cells gain the ability to leave the primary tumour and infiltrate other parts of the body. Recent studies have shown that a linkage between an unjamming transition and tumour progression indeed exists, which could be of importance when designing surgery and treatment approaches for cancer patients

no / When cells change functions or activities (such as during differentiation, response to extracellular stimuli, or migration), gene expression undergoes large-scale reprogramming, in cell type- and function-specific manners. Large changes in gene regulation require changes in chromatin architecture, which involve recruitment of chromatin remodeling enzymes and epigenomic modification enzymes to specific genomic loci. Transcription factors must also be accurately assembled at these loci. SATB1 is a genome organizer protein that facilitates these processes, providing a nuclear architectural platform that anchors hundreds of genes, through its interaction with specific genomic sequences; this activity allows expression of all these genes to be regulated in parallel, and enables cells to thereby alter their function. We review and describe future perspectives on SATB1 function in higher-order chromatin structure and gene regulation, and its role in metastasis of breast cancer and other tumor types.

Polysialic acid (polySia) is a carbohydrate polymer highly expressed during embryonic development but rarely expressed during postnatal development. Two polysialyltransferase (polyST) enzymes are responsible for the synthesis of polySia: ST8SiaII and ST8SiaIV. During oncogenesis polySia is re-expressed and it modulates cell-cell and cell-matrix adhesion, migration, invasion and metastasis. PolySia expression is strongly associated with poor clinical prognosis and correlates with aggressive and invasive disease in neuroblastoma and many other tumours. PolyST inhibition thus presents a novel, selective and largely unexplored therapeutic opportunity to reduce tumour dissemination. Progress towards development of polyST inhibitors has been limited by lack of an efficient technique for quantitative assessment of enzyme activity. We have validated a highly sensitive cell-based and cell-free high throughput HPLC-based inhibition assays. Using isogenic cell lines (C6-STX: polySia+/ST8SiaII+ and C6-WT: polySia-/ST8SiaII-) and naturally polySia expressing human neuroblastoma cells (SH-SY5Y), a set of ST8SiaII inhibitors designed and synthesised in house were evaluated for their ability to reduce polySia expression and to modulate cell migration in vitro. We have identified CMP-sialic acid precursors, including ICT-3176, which reduced polySia expression and tumour cell migration by up to 70%. These effects were only found in cell lines expressing ST8SiaII and polySia. Furthermore, we have investigated the possible additive anti-migratory effect of combining polyST inhibition with the inhibition of certain signalling pathways that have been previously suggested to be modulated by polySia expression. Out of these combinations it was found that combining ST8SiaII and C-MET/ALK inhibition had a synergistic effect on inhibiting cancer cell migration. Additionally, the effect of polySia expression on cancer cell behaviour under hypoxic conditions was examined, where it was found that polySia expression enhanced cell migration and survival and inhibits cell adhesion. In summary, polyST inhibitors which dramatically decrease cell migration in vitro through modulation of polySia assembly were identified, using optimised cell-free and cell-based assays. Initial investigations into the role of polySia in hypoxia were also accomplished. This work paves the way for development of a novel therapeutic for the treatment of neuroblastoma.

No description available.