The L1 adhesion molecule plays an important role in axon guidance and cell migration in the nervous system. L1 is also expressed by many human carcinomas. In addition to cell surface expression, the L1 ectodomain can be released by a metalloproteinase, but the biological function of this process is unknown. Here we demonstrate that membrane-proximal cleavage of L1 can be detected in tumors and ...

Mesenchymal stem cells (MSCs) show high expression of PD-L1. Exosomes can transmit signals between tumor and stromal cells; however, the effect tumor-derived exosomes on cell signaling pathways is unclear. The PD-L1 in bone marrow mesenchymal (BMMSCs) was detected by western blot RT-PCR. effects gastric cancer line-derived BMMSC migration conditioned medium from educated BMMSCs were analyzed. O...

It is unclear whether PD-L1 on tumor cells is sufficient for tumor immune evasion or simply correlates with an inflamed tumor microenvironment. We used three mouse tumor models sensitive to PD-1 blockade to evaluate the significance of PD-L1 on tumor versus nontumor cells. PD-L1 on nontumor cells is critical for inhibiting antitumor immunity in B16 melanoma and a genetically engineered melanoma...

Programmed cell death ligand 1 (PD-L1) is a negative regulator of the immune response that enables tumor cells to escape T-cell immunity. Although PD-L1 expression in cancer cells has been extensively studied, the expression of PD-L1 in stromal cells and its clinical significance remain largely unknown. Here, we show that bone marrow stromal cells express a low level of PD-L1 and that this mole...

On neural cells, the cell adhesion molecule L1 is generally found coexpressed with N-CAM. The two molecules have been suggested, but not directly shown, to affect each other's function. To investigate the possible functional relationship between the two molecules, we have characterized the adhesive interactions between the purified molecules and between cultured cells expressing them. Latex bea...

This study investigated the function of the adhesion molecule L1 in unmyelinated fibers of the peripheral nervous system (PNS) by analysis of L1- deficient mice. We demonstrate that L1 is present on axons and Schwann cells of sensory unmyelinated fibers, but only on Schwann cells of sympathetic unmyelinated fibers. In L1-deficient sensory nerves, Schwann cells formed but failed to retain normal...

Aberrant activation of Wnt/β-catenin signaling is common in most sporadic and inherited colorectal cancer (CRC) cells leading to elevated β-catenin/TCF transactivation. We previously identified the neural cell adhesion molecule L1 as a target gene of β-catenin/TCF in CRC cells. Forced expression of L1 confers increased cell motility, invasion, and tumorigenesis, and the induction of human CRC c...

PURPOSE Intrahepatic cholangiocarcinoma (ICC), a highly malignant hepatobiliary cancer, has a poor prognosis and is refractory to conventional therapies. The aim of this study is to discover a novel molecular target for the treatment of ICC. EXPERIMENTAL DESIGN To discover novel cancer-associated membrane antigens expressed in ICC cells, we generated monoclonal antibodies (mAb) by immunizing ...

L1-CAM, a neuronal cell adhesion receptor, is also expressed in a variety of cancer cells. Recent studies identified L1-CAM as a target gene of beta-catenin-T-cell factor (TCF) signaling expressed at the invasive front of human colon cancer tissue. We found that L1-CAM expression in colon cancer cells lacking L1-CAM confers metastatic capacity, and mice injected in their spleen with such cells ...

Abstract Although immune checkpoint blockade that targets the PD-L1 has revolutionized treatment of human cancers, only a small proportion patients positively respond to this form treatment. A limitation these therapies is they target and inhibit PD-L1’s extracellular function, which bind its receptor on PD-1 T cells cell cytotoxicity. Recent discoveries have shown expressed tumor can signal in...