Circulating tumor cells (CTCs) disseminating from primary tumor sites travel to distant organs and form secondary tumor sites, known as metastasis. After leaving the primary tumor microenvironment, CTCs enter the circulatory system where they routinely interact with immune cells. This interaction can paradoxically result in both limiting or promoting the metastatic potential of CTCs. The final steps of metastasis involve CTCs invaginating into the underlining tissue and forming secondary tumor sites. One plausible mechanism of CTCs leaving the circulatory system involves a similar process to leukocyte homing - selectin-mediated interaction. The scope of the work presented here can be divided into two parts: (a) exploiting the naturally occurring immune response called NETosis when neutrophils come into contact with cancer cells as a form of cancer therapy, and (b) gaining a better understanding of the mechanism of selectin- ligand interaction that playing a pivotal role in cancer metastasis and leukocyte homing. Immunotherapy is an emerging powerful clinical strategy for cancer therapy. NETosis is an innate immune response elicited by activated neutrophils to fight microbial infections. Activated neutrophils release DNA fibers decorated with anti-microbial proteins called neutrophil extracellular traps (NETs) into the extracellular space to trap and kill surrounding microbes. Here, we show tumor-derived IL-8 released by cancer cells also activates the release of NETs. Until now, there have been no existing technologies that leverage NETs as an anti-tumor drug delivery vehicle. In this study, we describe the re-engineering of neutrophils to express an apoptosis-inducing chimeric protein, supercharged eGFP-TRAIL, on NETs that can ensnare and kill tumor cells while retaining all of their anti-microbial capabilities. We observed significant TRAIL- induced apoptosis in tumor cells captured by TRAIL-decorated NETs. This work demonstrates NETs as a promising technology to deliver protein in response to local cytokine signals. The 3-member (E-, P-, L-) selectin family of cell adhesion molecules facilitates initial leukocyte tethering and subsequent cell rolling during the early stages of the inflammatory response via binding to glycoproteins expressing sialyl LewisX and sialyl LewisA (sLeX/A) to sites of inflammation and trauma. The extracellular microenvironments at these sites often become acidic. We investigated the influence of slightly acidic pH on the binding dynamics of selectins (P-, L-, and E-selectin) to P- selectin glycoprotein ligand-1 (PSGL-1) via computational modeling (molecular dynamics) and experimental rolling assays under shear in vitro. The P-selectin/PSGL-1 binding is strengthened at acidic pH, as evidenced by the formation of a new hydrogen bond (seen computationally) and the observed decrease in the rolling velocities of model cells. In the case of L-selectin/PSGL-1 binding dynamics, the binding strength and frequency increase at acidic pH, as indicated by the greater cell-rolling flux of neutrophils and slower rolling velocities of L-selectin-coated microspheres, respectively. The cell flux is most likely due to an increased population of L-selectin in the high-affinity conformation as pH decreases, whereas the velociti.

The survival rate for patients with metastatic vs. localized cancer is dramatically reduced. Most cancer-related deaths are associated with the formation of secondary tumors. In order to form a secondary tumor, cancer cells must detach from the primary tumor, using a complex series of steps change the surrounding tissue making its way to the circulatory system, survive within the circulation and evade the immune system, and leave the circulatory system at a distal site to form a secondary tumor. While circulating, cancer cells interact with the endothelial lining of the vasculature via a series of adhesive interactions that facilitate tethering mediated via transient bond formation with the selectin group of glycoproteins. This ultimately leads to firm adhesion of cancer cells to vessels in the initial steps of metastasis. Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL), identified based on its homology to the TNF superfamily, holds promise as a tumorspecific cancer therapeutic agent. Unlike other TNF family members, TRAIL specifically induces a death signal in transformed cells while sparing non-cancerous cells via a caspase-dependent pathway. In the present work, we exploit this phenomenon to deliver a receptor-mediated apoptosis signal to cancer cells under flow conditions. My studies show that cancer cells exhibit shear-dependent rolling behavior over a selectin-coated microcapillary flow chamber and that the density of the selectin molecule, along with the shear force imposed by the flowing fluid on the cancer cell play an important role in regulating the rolling velocity. Further, I have demonstrated that flowing cancer cells through a microtube functionalized with TRAIL and E-selectin is capable of killing the captured cancer cells. This killing is time-dependent and is more efficient compared to static conditions with immobilized TRAIL and E-selectin. The functionalized microtubes do not kill healthy blood and bone marrow cells neither do they activate!2 integrin present on leukocytes. Studies suggest that many cancer cells that are resistant to TRAIL can be sensitized by chemotherapy and radiation. To this extent, the microtube device was tested for use as adjuvant therapy. When pre-treating cells with sublethal doses of chemotherapeutic agent, a super-additive (greater than the sum of kill by individual agent) increase in kill rate was seen. This represents the first demonstration of a novel biomimetic method to capture metastatic cells from circulation and deliver an apoptotic signal, thereby reducing the metastatic load with a hope to improve patient survival. Using a different approach, nanoscale lipid particles decorated with two proteins are developed that would bind circulating cancer cells and kill them. Results show that the lipid nanoparticles bind to cells under conditions of uniform shear with high efficiency and kill over 50% of cells in 2 hours. When cancer cells were spiked in blood, a kill of over 90% was seen when compared to control lipid nanoparticles. Before these modalities become therapies, further studies evaluating the efficacy in animal models are necessary. However, these results show promising possibilities in killing metastatic cancer cells, thereby improving chances for patient survival.

The microcirculation is highly responsive to, and a vital participant in, the inflammatory response. All segments of the microvasculature (arterioles, capillaries, and venules) exhibit characteristic phenotypic changes during inflammation that appear to be directed toward enhancing the delivery of inflammatory cells to the injured/infected tissue, isolating the region from healthy tissue and the systemic circulation, and setting the stage for tissue repair and regeneration. The best characterized responses of the microcirculation to inflammation include impaired vasomotor function, reduced capillary perfusion, adhesion of leukocytes and platelets, activation of the coagulation cascade, and enhanced thrombosis, increased vascular permeability, and an increase in the rate of proliferation of blood and lymphatic vessels. A variety of cells that normally circulate in blood (leukocytes, platelets) or reside within the vessel wall (endothelial cells, pericytes) or in the perivascular space (mast cells, macrophages) are activated in response to inflammation. The activation products and chemical mediators released from these cells act through different well-characterized signaling pathways to induce the phenotypic changes in microvessel function that accompany inflammation. Drugs that target a specific microvascular response to inflammation, such as leukocyte-endothelial cell adhesion or angiogenesis, have shown promise in both the preclinical and clinical studies of inflammatory disease. Future research efforts in this area will likely identify new avenues for therapeutic intervention in inflammation. Table of Contents: Introduction / Historical Perspectives / Anatomical Considerations / Impaired Vasomotor Responses / Capillary Perfusion / Angiogenesis / Leukocyte-Endothelial Cell Adhesion / Platelet-Vessel Wall Interactions / Coagulation and Thrombosis / Endothelial Barrier Dysfunction / Epilogue / References

This volume examines in detail the role of chronic inflammatory processes in the development of several types of cancer. Leading experts describe the latest results of molecular and cellular research on infection, cancer-related inflammation and tumorigenesis. Further, the clinical significance of these findings in preventing cancer progression and approaches to treating the diseases are discussed. Individual chapters cover cancer of the lung, colon, breast, brain, head and neck, pancreas, prostate, bladder, kidney, liver, cervix and skin as well as gastric cancer, sarcoma, lymphoma, leukemia and multiple myeloma.

This comprehensive encyclopedic reference provides rapid access to focused information on topics of cancer research for clinicians, research scientists and advanced students. Given the overwhelming success of the first edition, which appeared in 2001, and fast development in the different fields of cancer research, it has been decided to publish a second fully revised and expanded edition. With an A-Z format of over 7,000 entries, more than 1,000 contributing authors provide a complete reference to cancer. The merging of different basic and clinical scientific disciplines towards the common goal of fighting cancer makes such a comprehensive reference source all the more timely.