Angiogenesis-Enabled Human Ovarian Tumor Microenvironment-Chip Evaluates Pathophysiology of Platelets in Microcirculation.

The tumor microenvironment (TME) promotes angiogenesis for its growth through the recruitment of multiple cells and signaling mechanisms. For example, TME actively recruits and activates platelets from the microcirculation to facilitate metastasis, but platelets may simultaneously also support tumor angiogenesis. Here, to model this complex pathophysiology within the TME that involves a signaling triad of cancer cells, sprouting endothelial cells, and platelets, an angiogenesis-enabled tumor microenvironment chip (aTME-Chip) is presented. This platform recapitulates the convergence of physiology of angiogenesis and platelet function within the ovarian TME and describes the contribution of platelets in promoting angiogenesis within an ovarian TME. By including three distinct human ovarian cancer cell-types, the aTME-Chip quantitatively reveals the following outcomes-first, introduction of platelets significantly increases angiogenesis; second, the temporal dynamics of angiogenic signaling is dependent on cancer cell type; and finally, tumor-educated platelets either activated exogenously by cancer cells or derived clinically from a cancer patient accelerate tumor angiogenesis. Further, analysis of effluents available from aTME-Chip validate functional outcomes by revealing changes in cytokine expression and several angiogenic and metastatic signaling pathways due to platelets. Collectively, this tumor microphysiological system may be deployed to derive antiangiogenic targets combined with antiplatelet treatments to arrest cancer metastasis.

Engineering Lymphangiogenesis-On-Chip: The Independent and Cooperative Regulation by Biochemical Factors, Gradients, and Interstitial Fluid Flow.

Despite the crucial role of lymphangiogenesis during development and in several diseases with implications for tissue regeneration, immunity, and cancer, there are significantly fewer tools to understand this process relative to angiogenesis. While there has been a major surge in modeling angiogenesis with microphysiological systems, they have not been rigorously optimized or standardized to enable the recreation of the dynamics of lymphangiogenesis. Here, a Lymphangiogenesis-Chip (L-Chip) is engineered, within which new sprouts form and mature depending upon the imposition of interstitial flow, growth factor gradients, and pre-conditioning of endothelial cells with growth factors. The L-Chip reveals the independent and combinatorial effects of these mechanical and biochemical determinants of lymphangiogenesis, thus ultimately resulting in sprouts emerging from a parent vessel and maturing into tubular structures up to 1 mm in length within 4 days, exceeding prior art. Further, when the constitution of the pre-conditioning cocktail and the growth factor cocktail used to initiate and promote lymphangiogenesis are dissected, it is found that endocan (ESM-1) results in more dominant lymphangiogenesis relative to angiogenesis. Therefore, The L-Chip provides a foundation for standardizing the microfluidics assays specific to lymphangiogenesis and for accelerating its basic and translational science at par with angiogenesis.

Human tumor microenvironment chip evaluates the consequences of platelet extravasation and combinatorial antitumor-antiplatelet therapy in ovarian cancer.

Platelets extravasate from the circulation into tumor microenvironment, enable metastasis, and confer resistance to chemotherapy in several cancers. Therefore, arresting tumor-platelet cross-talk with effective and atoxic antiplatelet agents in combination with anticancer drugs may serve as an effective cancer treatment strategy. To test this concept, we create an ovarian tumor microenvironment chip (OTME-Chip) that consists of a platelet-perfused tumor microenvironment and which recapitulates platelet extravasation and its consequences. By including gene-edited tumors and RNA sequencing, this organ-on-chip revealed that platelets and tumors interact through glycoprotein VI (GPVI) and tumor galectin-3 under shear. Last, as proof of principle of a clinical trial, we showed that a GPVI inhibitor, Revacept, impairs metastatic potential and improves chemotherapy. Since GPVI is an antithrombotic target that does not impair hemostasis, it represents a safe cancer therapeutic. We propose that OTME-Chip could be deployed to study other vascular and hematological targets in cancer.