Publications by authors named "Patrick Nasarre"

Pancreatic adenocarcinoma (PDAC) is one of the deadliest cancers, with five-year survival rates of 9%. We hypothesized that secreted frizzled-related protein 2 (SFRP2) may influence stromal growth in pancreatic cancer, since it increases fibrosis and collagen production in non-neoplastic pathologies. We assessed SFRP2 value as a biomarker and assessed its function in PDAC.

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Secreted frizzled-related protein 2 (SFRP2) promotes the migration/invasion of metastatic osteosarcoma (OS) cells and tube formation by endothelial cells. However, its function on T-cells is unknown. We hypothesized that blocking SFRP2 with a humanized monoclonal antibody (hSFRP2 mAb) can restore immunity by reducing CD38 and PD-1 levels, ultimately overcoming resistance to PD-1 inhibitors.

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Objective: Innate and acquired resistance is the principle factor limiting the efficacy of tyrosine kinase inhibitors in lung cancer. We have observed a dramatic upregulation of the cell surface co-receptor neuropilin-2b in lung cancers clinically treated with tyrosine kinase inhibitors correlating with acquired resistance. We hypothesize that neuropilin-2b plays a functional role in acquired tyrosine kinase inhibitor resistance.

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Background: We previously reported that secreted frizzled-related protein-2 (SFRP2) is expressed in a variety of tumors, including sarcoma and breast carcinoma, and stimulates angiogenesis and inhibits tumor apoptosis. Therefore, we hypothesized that a humanized SFRP2 monoclonal antibody (hSFRP2 mAb) would inhibit tumor growth.

Methods: The lead hSFRP2 antibody was tested against a cohort of 22 healthy donors using a time course T-cell assay to determine the relative risk of immunogenicity.

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Adoptive transfer of tumor epitope-reactive T cells has emerged as a promising strategy to control tumor growth. However, chronically-stimulated T cells expanded for adoptive cell transfer are susceptible to cell death in an oxidative tumor microenvironment. Because oxidation of cell-surface thiols also alters protein functionality, we hypothesized that increasing the levels of thioredoxin (Trx), an antioxidant molecule facilitating reduction of proteins through cysteine thiol-disulfide exchange, in T cells will promote their sustained antitumor function.

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TRAF3-interacting protein 3 (TRAF3IP3) is expressed in the immune system and participates in cell maturation, tissue development, and immune response. In a previous study, we reported that TRAF3IP3 levels were substantially increased in the vasculature of breast cancer tissues, suggesting a proangiogenic role. In this study, we investigated TRAF3IP3 tumorigenic function.

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Secreted frizzled-related protein 2 (SFRP2) is a pro-angiogenic factor expressed in the vasculature of a wide variety of human tumors, and modulates angiogenesis via the calcineurin-dependent nuclear factor of activated T-cells cytoplasmic 3 (NFATc3) pathway in endothelial cells. However, until now, SFRP2 receptor for this pathway was unknown. In the present study, we first used amino acid alignments and molecular modeling to demonstrate that SFRP2 interaction with frizzled-5 (FZD5) is typical of Wnt/FZD family members.

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Neuropilins (NRP1 and NRP2) are co-receptors for heparin-binding growth factors and class 3 semaphorins. Different isoforms of NRP1 and NRP2 are produced by alternative splicing. We found that in non-small cell lung cancer (NSCLC) cell lines, transforming growth factor-β (TGFβ) signaling preferentially increased the abundance of NRP2b.

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Epithelial-mesenchymal transition (EMT) is one mechanism of acquired resistance to inhibitors of the epidermal growth factor receptor-tyrosine kinases (EGFR-TKIs) in non-small cell lung cancer (NSCLC). The precise mechanisms of EMT-related acquired resistance to EGFR-TKIs in NSCLC remain unclear. We generated erlotinib-resistant HCC4006 cells (HCC4006ER) by chronic exposure of EGFR-mutant HCC4006 cells to increasing concentrations of erlotinib.

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The semaphorins, discovered over 20 years ago, are a large family of secreted or transmembrane and glycophosphatidylinositol -anchored proteins initially identified as axon guidance molecules crucial for the development of the nervous system. It has now been established that they also play important roles in organ development and function, especially involving the immune, respiratory, and cardiovascular systems, and in pathological disorders, including cancer. During tumor progression, semaphorins can have both pro- and anti-tumor functions, and this has created complexities in our understanding of these systems.

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The epithelial to mesenchymal transition (EMT) enables epithelial cells with a migratory mesenchymal phenotype. It is activated in cancer cells and is involved in invasion, metastasis and stem-like properties. ZEB1, an E-box binding transcription factor, is a major suppressor of epithelial genes in lung cancer.

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The epithelial-mesenchymal transition (EMT) and its reversal, mesenchymal-epithelial transition (MET), are fundamental processes involved in tumor cell invasion and metastasis. SEMA3F is a secreted semaphorin and tumor suppressor downregulated by TGF-β1 and ZEB1-induced EMT. Here, we report that neuropilin (NRP)-2, the high-affinity receptor for SEMA3F and a coreceptor for certain growth factors, is upregulated during TGF-β1-driven EMT in lung cancer cells.

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The HLX gene encoding a diverged homeobox transcription factor has been found to be up-regulated by vascular endothelial growth factor-A (VEGF-A) in endothelial cells. We have now investigated the gene repertoire induced by HLX and its potential biologic function. HLX strongly increased the transcripts for several repulsive cell-guidance proteins including UNC5B, plexin-A1, and semaphorin-3G.

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The epithelial to mesenchymal transition (EMT) is a developmental process enabling epithelial cells to gain a migratory mesenchymal phenotype. In cancer, this process contributes to metastases; however the regulatory signals and mechanistic details are not fully elucidated. Here, we sought to identify the subset of genes regulated in lung cancer by ZEB1, an E-box transcriptional repressor known to induce EMT.

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Guidance molecules were first described in the nervous system to control axon outgrowth direction. They are also widely expressed outside the nervous system where they control cell migration, tissue development and establishment of the vascular network. In addition, they are involved in cancer development, tumor angiogenesis and metastasis.

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The angiopoietin/Tie2 system has been identified as the second vascular-specific receptor tyrosine kinase system controlling vessel assembly, maturation, and quiescence. Angiopoietin-2 (Ang-2) is prominently up-regulated in the host-derived vasculature of most tumors, making it an attractive candidate for antiangiogenic intervention. Yet, the net outcome of Ang-2 functions on tumor angiogenesis is believed to be contextual depending on the local cytokine milieu.

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Loss of SEMA3F occurs frequently in lung cancer and correlates with advanced stage of disease. We previously reported that SEMA3F blocked tumor formation by H157 lung cancer cells in a rat orthotopic model. This was associated with loss of activated alpha(V)beta(3) integrin, impaired cell adhesion to extracellular matrix components, and down-regulation of phospho-extracellular signal-regulated kinase 1/2 (ERK1/2).

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Semaphorins, a family of genes encoding guidance molecules in the nervous system, influence a variety of cellular mechanisms including migration, proliferation and cytoskeleton reorganization. Interestingly, many members are expressed throughout lymphoid tissues and by different immune cells like lymphocytes, NK, monocytes and dendritic cells. Besides, the array of functions semaphorins usually regulate during organogenesis coincide with several key events required for the initiation as well as the regulation of the host immune response.

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Semaphorins, first described as axon guidance molecules, play an essential role in neural development, angiogenesis and immunological response. In 1996, two semaphorin genes, SEMA3B and SEMA3F, were isolated from chromosomal region 3p21.3 believed to contain a tumor suppressor gene based on frequent loss of heterozygosity in lung and breast cancer.

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Loss of the 3p21.3-encoded semaphorins, SEMA3B and SEMA3F, is implicated in lung cancer development. Although both antagonize VEGF binding/response to neuropilin (NRP) receptors, in lung cancer lines, SEMA3F is predominantly expressed and preferentially utilizes NRP2.

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Previously, we demonstrated that loss of SEMA3F, a secreted semaphorin encoded in 3p21.3, is associated with higher stages in lung cancer and primary tumor cells studied with anti-vascular endothelial growth factor (VEGF) and SEMA3F antibodies. In vitro, SEMA3F inhibits cell spreading; this activity is opposed by VEGF.

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SEMA3F, isolated from a 3p21.3 deletion, has antitumor activity in transfected cells, and protein expression correlates with tumor stage and histology. In primary tumors, SEMA3F and VEGF surface staining is inversely correlated.

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