Enhanced L1CAM expression on pancreatic tumor endothelium mediates selective tumor cell transmigration.

L1 cell adhesion molecule (L1CAM) is a transmembrane cell adhesion molecule initially defined as a promigratory molecule in the developing nervous system that appears to be also expressed in some endothelial cells. However, little is known about the functional role of L1CAM on endothelial cells. We observed that L1CAM expression was selectively enhanced on endothelium associated with pancreatic adenocarcinoma in situ and on cultured pancreatic tumor-derived endothelial cells in vitro.

Detection and functional analysis of tumor infiltrating T-lymphocytes (TIL) in liver metastases from colorectal cancer.

Background: Tumor-infiltrating T lymphocytes (TIL) play an important role in primary colorectal cancer, but their activity in liver metastases has not yet been investigated. The aim of this study was to examine whether tumor-selective infiltration, activation, and cytotoxic activity of TIL can be demonstrated in situ in colorectal liver metastases.

Methods: TIL were obtained from liver metastases and corresponding normal liver tissue of 16 patients with colorectal liver metastases.

Role of tumor endothelium in CD4+ CD25+ regulatory T cell infiltration of human pancreatic carcinoma.

Background: Regulatory T (Treg) cells have been detected in human carcinomas and may play a role in preventing the rejection of malignant cells.

Methods: We quantified Treg cells and the expression of the addressins and the respective ligands that attract them in blood and in human pancreatic tumors and adjacent nonmalignant tissues from 47 patients. The capacity of Treg cells to adhere to and transmigrate through autologous endothelial cells was tested in vitro using spheroid adhesion assays and in vivo using a xenotransplant NOD/SCID model and in the presence and absence of antibodies to addressins.

Tumor infiltrating T lymphocytes in colorectal cancer: Tumor-selective activation and cytotoxic activity in situ.

Objective: To examine whether tumor-selective infiltration, activation, and cytotoxic activity of tumor infiltrating T lymphocytes (TIL) can be demonstrated in situ in colorectal cancer samples.

Summary Background Data: Recent studies indicated a correlation between the presence of TIL and an improved prognosis in colorectal cancer. However, tumor-selective activation and cytotoxic activity of CD8 TIL in situ in colorectal cancer patients have not yet been examined.

High frequencies of functional tumor-reactive T cells in bone marrow and blood of pancreatic cancer patients.

Pancreatic cancer is characterized by aggressive growth and treatment resistance. New approaches include immunotherapeutic strategies but the type and extent of spontaneous immune responses against tumor antigens remains unclear. A dominance of TH2 cytokines in patients' sera reported previously suggests systemic tumor-induced immunosuppression, potentially inhibiting the induction of tumor-reactive T cells.