Humans ; Psoriasis ; etiology ; therapy ; Signal Transduction ; Vascular Endothelial Growth Factor Receptor-1 ; antagonists & inhibitors ; physiology ; Vascular Endothelial Growth Factor Receptor-2 ; antagonists & inhibitors ; physiology

The current study was purposed to investigate the inhibitory effect of human soluble vascular endothelial growth factor-1 (sFLT-1) on the proliferation of leukemic cells in vitro. Reverse transcription-polymerase chain reaction (RT-PCR) was used to detect the VEGF mRNA and VEGF-R1 (FLT-1) mRNA in K562, HL60, U937 leukemic cell lines and bone marrow LTC-IC. Flow cytometry was used to detect the VEGF and VEGF-R1 (FLT-1) in all above-mentioned cells. VEGF concentrations in the cell culture supernatants were determined by enzyme-linked immunosorbent assay (ELISA). Cell proliferation was determined by MTT after adding sFLT-1 to K562, HL60 and LTC-IC culture system. The result showed that expression of VEGF could be detected in K562, HL60, U937 leukemic cell lines and LTC-IC, especially K562, K562 and HL60 cell lines also expressed FLT-1, but a little expression was found in U937 and LTC-IC. sFLT-1 could effectively inhibit the growth of K562 and HL60 cell lines in dose-dependent manner. The highest inhibition rate was found at 48 hours after adding sFLT-1. It is concluded that sFLT-1 can inhibit the growth of some leukemic cell lines, and the inhibition effect enhances as the concentration of the sFLT-1 increase, but sFLT -1 not influence the proliferation of normal marrow cells.
Cell Proliferation ; drug effects ; HL-60 Cells ; Humans ; K562 Cells ; RNA, Messenger ; biosynthesis ; genetics ; U937 Cells ; Vascular Endothelial Growth Factor A ; antagonists & inhibitors ; biosynthesis ; genetics ; Vascular Endothelial Growth Factor Receptor-1 ; biosynthesis ; genetics ; physiology

Pancreatic ductal adenocarcinoma is one of the most dreaded malignancies and the 5th leading cause of cancer-related death in Korea. Late diagnosis and unfavorable response to both chemotherapy and radiotherapy result in exceptionally poor prognosis. Recently, the rapid advances of molecular biology allowed an in-depth understanding of pancreatic carcinogenesis, and there are many attempts to modulate signal pathway using specific targeted agent. However, the most of them have so far failed to improve survival significantly except erlotinib. The real challenge is now how these impressive advances of molecular biology could be successfully integrated into better clinical implications. Herein, we summarize the latest insights into the carcinogenesis, and their repercussions for novel targeted agents for pancreatic cancer, and provide a review of recent clinical trials using molecular targeted therapy.
Antineoplastic Agents/*therapeutic use ; Epigenesis, Genetic ; Humans ; Mitogen-Activated Protein Kinase Kinases/antagonists & inhibitors/metabolism ; Molecular Targeted Therapy ; Pancreatic Neoplasms/*drug therapy/metabolism/pathology ; Poly(ADP-ribose) Polymerases/antagonists & inhibitors/metabolism ; Receptor, Epidermal Growth Factor/antagonists & inhibitors/metabolism ; Receptor, IGF Type 1/antagonists & inhibitors/metabolism ; Vascular Endothelial Growth Factor A/antagonists & inhibitors/metabolism

Pancreatic ductal adenocarcinoma is one of the most dreaded malignancies and the 5th leading cause of cancer-related death in Korea. Late diagnosis and unfavorable response to both chemotherapy and radiotherapy result in exceptionally poor prognosis. Recently, the rapid advances of molecular biology allowed an in-depth understanding of pancreatic carcinogenesis, and there are many attempts to modulate signal pathway using specific targeted agent. However, the most of them have so far failed to improve survival significantly except erlotinib. The real challenge is now how these impressive advances of molecular biology could be successfully integrated into better clinical implications. Herein, we summarize the latest insights into the carcinogenesis, and their repercussions for novel targeted agents for pancreatic cancer, and provide a review of recent clinical trials using molecular targeted therapy.
Antineoplastic Agents/*therapeutic use ; Epigenesis, Genetic ; Humans ; Mitogen-Activated Protein Kinase Kinases/antagonists & inhibitors/metabolism ; Molecular Targeted Therapy ; Pancreatic Neoplasms/*drug therapy/metabolism/pathology ; Poly(ADP-ribose) Polymerases/antagonists & inhibitors/metabolism ; Receptor, Epidermal Growth Factor/antagonists & inhibitors/metabolism ; Receptor, IGF Type 1/antagonists & inhibitors/metabolism ; Vascular Endothelial Growth Factor A/antagonists & inhibitors/metabolism

PURPOSE: Hypoxia-inducible factor-1alpha (HIF-1alpha) increases transcription of the vascular endothelial growth factor (VEGF) gene. Inhibition of VEGF abolishes VEGF mediated induction of HIF-1alpha. Recent reports suggested that HIF-1alpha also mediated the induction of class III beta-tubulin (TUBB3) in hypoxia. TUBB3 confers resistance to taxanes. Inhibition of VEGF may decrease the expression of HIF-1alpha and TUBB3. This study was undertaken to investigate the roles of vascular endothelial growth factor receptor (VEGFR) in gastric cancer cell behavior and to identify methods to overcome paclitaxel resistance in vitro. MATERIALS AND METHODS: The protein expression levels of HIF-1alpha and TUBB3 were measured in human gastric cancer cell lines (AGS) under normoxic and hypoxic conditions. The relationship between TUBB3 and paclitaxel resistance was assessed with small interfering TUBB3 RNA. AGS cells were treated with anti-VEGFR-1, anti-VEGFR-2, placental growth factor (PlGF), bevacizuamb, and paclitaxel. RESULTS: Hypoxia induced paclitaxel resistance was decreased by knockdown of TUBB3. Induction of HIF-1alpha and TUBB3 in AGS is VEGFR-1 mediated and PlGF dependent. Hypoxia-dependent upregulation of HIF-1alpha and TUBB3 was reduced in response to paclitaxel treatment. Expressions of HIF-1alpha and TUBB3 were most decreased when AGS cells were treated with a combination of paclitaxel and anti-VEGFR-1. AGS cell cytotoxicity was most increased in response to paclitaxel, anti-VEGFR-1, and anti-VEGFR-2. CONCLUSION: We suggest that blockade of VEGFR-1 and VEGFR-2 enhances paclitaxel sensitivity in TUBB3-expressing gastric cancer cells.
Angiogenesis Inhibitors/pharmacology ; Antibodies, Monoclonal, Humanized/pharmacology ; Antineoplastic Agents, Phytogenic/*pharmacology ; Cell Hypoxia ; Cell Line, Tumor ; *Drug Resistance, Neoplasm ; Gene Expression Regulation, Neoplastic/drug effects ; Gene Knockdown Techniques ; Humans ; Hypoxia-Inducible Factor 1, alpha Subunit/metabolism ; Paclitaxel/*pharmacology ; Pregnancy Proteins/pharmacology ; Stomach Neoplasms/drug therapy/genetics ; Tubulin/genetics/metabolism ; Vascular Endothelial Growth Factor Receptor-1/antagonists & inhibitors/*physiology ; Vascular Endothelial Growth Factor Receptor-2/antagonists & inhibitors/*physiology

The purpose of this study was to devise an expanded ischemic flap model and to investigate the role of AMD-3100 (Plerixafor, chemokine receptor 4 inhibitor) in this model by confirming its effect on mobilization of stem cells from the bone marrow. Male Sprague-Dawley rats were used as an animal research model. The mobilization of stem cells from the bone marrow was confirmed in the AMD-3100-treated group. The fractions of endothelial progenitor cells (EPC) and the vascular endothelial growth factor receptor (VEGFR) 2+ cells in the peripheral blood were increased in groups treated with AMD-3100. The expression of vascular endothelial growth factor (VEGF) was increased in response to expansion or AMD injection. The expression of stromal cell derived factor (SDF)-1 and VEGFR2 were increased only in unexpanded flap treated with AMD-3100. Treatment with AMD-3100 increased both the number and area of blood vessels. However, there were no statistically significant differences in the survival area or physiologic microcirculation in rats from the other groups. This endogenous neovascularization induced by AMD-3100 may be a result of the increase in both the area and number of vessels, as well as paracrine augmentation of the expression of VEGF and EPCs. However, the presence of a tissue expander under the flap could block the neovascularization between the flap and the recipient regardless of AMD-3100 treatment and expansion.
Animals ; Anti-HIV Agents/pharmacology ; Bone Marrow Cells/cytology ; Chemokine CXCL12/biosynthesis ; Endothelial Progenitor Cells/*cytology ; Hematopoietic Stem Cells/*cytology ; Heterocyclic Compounds/*pharmacology ; Hypoxia-Inducible Factor 1, alpha Subunit/metabolism ; Male ; Neovascularization, Physiologic ; Nitric Oxide Synthase Type III/metabolism ; Rats ; Rats, Sprague-Dawley ; Receptors, CXCR4/antagonists & inhibitors ; Surgical Flaps/*blood supply/surgery ; Tissue Expansion/*methods ; Vascular Endothelial Growth Factor A/biosynthesis ; Vascular Endothelial Growth Factor Receptor-2/biosynthesis/metabolism

To evaluate the effect of imatinib mesylate (STI571) on primitive/committed malignant progenitor cells in chronic myelogenous leukemia (CML) and to further elucidate the mechanisms involved in CML relapse and in some CML cells resistant to STI571, bone marrow-derived malignant bcr/abl-positive, Flk1(+)CD31CD34(-) cells with hemangioblastic characteristics from CML patients were grown in Methocult GF+ media with or without STI571, and inhibitory effect of STI571 on proliferation of differentiated and differentiating, bcr/abl(+), Flk1(+)CD31CD34(-) cells with hemangioblastic characteristics was investigated in vitro. The results showed that in vitro exposure to 5 micromol/L STI571 (the concentration of STI571 usually achieved in patients is 1-2 micromol/L) for 96 hours inhibited bcr/abl(+) committed progenitors (colony-forming cells, CFCs). No evident suppression of normal primitive, bcr/abl(+), and Flk1(+)CD31(-)CD34(-) cells were observed. It is concluded that CML primitive stem cells remain viable in the presence of STI571 and that inhibition of bcr/abl tyrosine kinase by STI571 restores normal hematopoiesis by removing the proliferative advantage of CML committed progenitors but that elimination of all CML progenitors may not occur. So despite dramatic short-term responses in vivo, such in vitro resistance to STI571, may translate into disease relapse after prolonged therapy.
Antigens, CD34 ; analysis ; genetics ; Benzamides ; Bone Marrow Cells ; drug effects ; metabolism ; pathology ; Cell Differentiation ; drug effects ; Cell Proliferation ; drug effects ; Drug Resistance, Neoplasm ; Fluorescent Antibody Technique ; Fusion Proteins, bcr-abl ; genetics ; metabolism ; Hematopoietic Stem Cells ; drug effects ; metabolism ; pathology ; Humans ; Imatinib Mesylate ; In Situ Hybridization, Fluorescence ; Leukemia, Myelogenous, Chronic, BCR-ABL Positive ; blood ; genetics ; metabolism ; Piperazines ; pharmacology ; Platelet Endothelial Cell Adhesion Molecule-1 ; analysis ; genetics ; Protein Kinase Inhibitors ; pharmacology ; Protein-Tyrosine Kinases ; antagonists & inhibitors ; Pyrimidines ; pharmacology ; Reverse Transcriptase Polymerase Chain Reaction ; Vascular Endothelial Growth Factor Receptor-2 ; analysis ; genetics