Surface-bound TGF-beta1 on effusion-derived exosomes participates in maintenance of number and suppressive function of regulatory T-cells in malignant effusions.

Background: This study analysed the contribution of malignant-effusion derived exosomes (Eff-Ex) to the number and function of regulatory T-cells (Treg) in malignant effusions.

Patients And Methods: Eff-Ex were collected from the malignant effusions of 24 cancer patients. Peripheral blood mononuclear cells (PBMCs) were co-cultured with different concentrations of Eff-Ex.

Intratumoral CD8(+) T/FOXP3 (+) cell ratio is a predictive marker for survival in patients with colorectal cancer.

The human immune system consists of a balance between immune surveillance against non-self antigens and tolerance of self-antigens. CD8(+) T cells and CD4(+) regulatory T cells (Tregs) are the main players for immune surveillance and tolerance, respectively. We examined immunohistochemically the immunological balance at the tumor site using 94 surgically resected colorectal cancer tissues.

VEGFR2 is selectively expressed by FOXP3high CD4+ Treg.

CD25+ FOXP3+CD4+ T cells (Treg) have been considered to play an important role in immune tolerance against several tumor antigens. It has also been indicated that high-level expression of FOXP3 (FOXP3high) is sufficient to confer suppressive activity to normal non-Treg. Here, we showed for the first time that vascular endothelial growth factor receptor 2 (VEGFR2) is selectively expressed by FOXP3high but not FOXP3low Treg.

Lipopolysaccharide (LPS) increases the invasive ability of pancreatic cancer cells through the TLR4/MyD88 signaling pathway.

Background: Inflammation plays a multifaceted role in cancer progression, and NF-kappaB is one of the key factors connecting inflammation with cancer progression. We have shown that lipopolysaccharide (LPS) promotes NF-kappaB activation in colon cancer cells and pancreatic cancer cells. However, it is unclear why inflammatory stimuli can induce NF-kappaB activation in cancer cells.

The contribution of vascular endothelial growth factor to the induction of regulatory T-cells in malignant effusions.

It has been suggested that immunosuppressive cytokines such as transforming growth factor beta (TGF-beta) and interleukin 10 play an important role in the induction and/or maintenance of regulatory T-cells (Tregs) in patients with cancer. In the present study, whether or not vascular endothelial growth factor (VEGF) contributes to the induction and/or maintenance of Tregs was examined, because of experience with a patient in whom a positive correlation between VEGF concentration and the percentage of Tregs (% Tregs) among the total CD4(+) T-cells in the pleural effusion was found during dendritic cell activated lymphocyte therapy. CD4(+)CD25(high) T-cells were estimated as Tregs in the present study.

A protein-bound polysaccharide, PSK, enhances tumor suppression induced by docetaxel in a gastric cancer xenograft model.

Background: We have reported previously that docetaxel (TXT) induces apoptosis and nuclear factor-kappaB (NF-kappaB) activation, and that blockade of NF-kappaB activation augments TXT-induced apoptosis in human gastric cancer cells. In addition, we have also shown that a protein-bound polysaccharide PSK enhances TXT-induced apoptosis through NF-kappaB inhibition in human pancreatic cancer cells. Based on these observations, in the present study the possibility that PSK could enhance TXT-mediated tumor suppression was examined in vivo and in vitro.

Long-term outcome of immunotherapy for patients with refractory pancreatic cancer.

Background: Pancreatic cancer is one of the most fatal human cancers, with a 5-year survival rate of <5% . Although new chemotherapies have been used for pancreatic cancer, the outcome is still poor. Here, we retrospectively analyzed the outcome of immunotherapy in pancreatic cancer patients and revealed the potential of immunotherapy in advanced pancreatic cancer treatment.

Enhancement of paclitaxel-induced apoptosis by inhibition of mitogen-activated protein kinase pathway in colon cancer cells.

Resistance to chemotherapy represents a major obstacle to improving the survival of patients with colorectal cancer. In this study, the inhibition of the mitogen-activated protein kinase (MAPK) pathway was demonstrated to markedly enhance the apoptosis of colon cancer cells induced by paclitaxel, one of the key chemotherapeutic drugs widely used to treat various types of cancer. The treatment of the colon cancer cell lines SW480 and DLD-1 with paclitaxel resulted in increased activation of the MAPK pathway, which was blocked by PD98059, a MEK inhibitor.

Regulatory T-cells are possible effect prediction markers of immunotherapy for cancer patients.

We previously showed that a combination therapy with tumor cell-pulsed monocyte-derived dendritic cells (DCs) and activated lymphocytes was well tolerated in patients with disseminated carcinomas. Recently, accumulating evidence has indicated that regulatory T-cells (Tregs), a unique population of CD4+ T-cells, are increased in patients with several advanced malignancies and prevent cell-mediated immune responses against tumors. However, reports analyzing the relationship between the Tregs population and the effects of immunotherapy are extremely rare.

Gli1 contributes to the invasiveness of pancreatic cancer through matrix metalloproteinase-9 activation.

The hedgehog (Hh) signaling pathway has been reported to be associated with the growth of pancreatic cancer, but its role in the invasive phenotype is poorly understood. Therefore, we investigated the role of the Hh pathway in pancreatic cancer cell invasiveness using a Matrigel invasion assay. Blockade of the Hh pathway by cyclopamine inhibited pancreatic cancer cell invasion in association with a decreased expression of matrix metalloproteinase (MMP)-9.

Crosstalk of hedgehog and Wnt pathways in gastric cancer.

Morphogenic signals like Hedgehog (Hh) and Wnt are reported to play critical roles in the progression of gastric cancer. We aimed to assess the relationship between Hh and Wnt signaling pathways. In 58 gastric cancer specimens, Wnt pathway activation was inversely correlated with Hh pathway activation.

Gamma-secretase inhibitors enhance taxane-induced mitotic arrest and apoptosis in colon cancer cells.

Background & Aims: Colorectal cancers are resistant to conventional chemotherapeutic treatments, including taxanes. gamma-Secretase is a multimeric membrane protein complex responsible for the intramembrane proteolysis of various type I transmembrane proteins, including amyloid beta-precursor protein and Notch. gamma-Secretase inhibitors have attracted increasing interest as anticancer drugs because of their ability to inhibit Notch signaling.

A large quantity of CD3-/CD19-/CD16- lymphocytes in malignant pleural effusion from a patient with recurrent cholangio cell carcinoma.

Tumor infiltrating lymphocytes (TILs) are candidates for adoptive cellular immunotherapy. Here we report on a patient whose TILs presented unusual lymphocyte antigens. Pleural effusions were collected from a 47-year-old man with recurrent cholangio cell carcinoma and malignant effusion.