Glutamine is a conditionally essential amino acid for the growth and survival of rapidly proliferating cancer cells. Many cancers are addicted to glutamine, and as a result, targeting glutamine metabolism has been explored clinically as a therapeutic approach. Glutamine-catalyzing enzymes are highly expressed in primary and metastatic head and neck squamous cell carcinoma (HNSCC).
View Article and Find Full Text PDFPancreatic ductal adenocarcinoma (PDAC) cells use glutamine (Gln) to support proliferation and redox balance. Early attempts to inhibit Gln metabolism using glutaminase inhibitors resulted in rapid metabolic reprogramming and therapeutic resistance. Here, we demonstrated that treating PDAC cells with a Gln antagonist, 6-diazo-5-oxo-L-norleucine (DON), led to a metabolic crisis in vitro.
View Article and Find Full Text PDFGlutamine is a conditionally essential amino acid consumed by rapidly proliferating cancer cells, which deprives the same fuel from immune cells and contributes to tumor immune evasion. As such, the broad antagonism of glutamine in tumors and the tumor microenvironment may lead to direct antitumor activity and stimulation of antitumoral immune responses. DRP-104 (sirpiglenastat) was designed as a novel prodrug of the broad-acting glutamine antagonist 6-diazo-5-oxo-L-norleucine (DON).
View Article and Find Full Text PDFImprime PGG (Imprime) is in late-stage clinical development as a combinatorial agent with several therapeutic modalities. Here we present pre-clinical mechanistic data supportive of Imprime, a soluble yeast β-1,3/1,6-glucan pathogen-associated molecular pattern able to prime innate immune cells in a Dectin-1dependent manner. In tumor-free mice, Imprime evoked broad innate immune responses (type I interferon signature, mobilization of myeloid cells, dendritic cell and monocyte/macrophage expression of co-stimulatory ligands like CD86, and activation of natural killer cells).
View Article and Find Full Text PDFExpression of the TAM (TYRO3, AXL, MER) family of receptor tyrosine kinases (RTK) has been associated with cancer progression, metastasis, and drug resistance. In immune cells, TAM RTKs can dampen inflammation in favor of homeostatic wound-healing responses, thus potentially contributing to the evasion of cancer cells from immune surveillance. Here we characterize the small-molecule RXDX-106 as a selective and potent pan-TAM RTK inhibitor with slow dissociation kinetics and significant antitumor activity in multiple syngeneic tumor models.
View Article and Find Full Text PDFArboreous fruit of Schisandra chinensis Baillon, Schisandra Fruit (SF), is a crude drug used in Japanese traditional Kampo medicine. The marker compounds of SF for quality control are lignans, such as schizandrin (Sz) and gomisin A (GmA). Kampo formulation containing SF is usually prepared as decoctions in the dosage form of whole crude drug (W), as its size is small enough to measure using a spoon.
View Article and Find Full Text PDFIntroduction: An emerging therapy in oncology is the induction of apoptotic cell death through anti-death receptor therapy. However, pancreatic cancer is resistant to apoptosis including anti-death receptor therapy. We have previously described how triptolide decreases resistance to apoptosis in pancreatic cancer cells in vitro and in vivo.
View Article and Find Full Text PDFOvarian cancer cells use integrins to attach to the peritoneal wall. Integrin alpha(5)beta(1) is also the target for the angiogenesis inhibitor, endostatin. Therefore, the ability of endostatin to competitively inhibit tumor cell seeding of the peritoneum was investigated.
View Article and Find Full Text PDFInt J Cancer
December 2007
Endostatin, a C-terminal fragment of collagen type XVIII, is one of the well-characterized endogenous inhibitors of angiogenesis. Endostatin is known to bind integrin alpha(5)beta(1), which is upregulated on tumor endothelium. Most of the ovarian cancer cells express significant amounts of alpha(5)beta(1) integrin, which is important for ovarian cancer cells to attach to the peritoneal wall.
View Article and Find Full Text PDFObjective: To determine the impact of thalidomide and angiostatin on tumor growth, angiogenesis, and apoptosis in a xenograft model of cervical cancer.
Methods: Human umbilical endothelial cells were treated with angiostatin or thalidomide and bFGF-induced proliferation was assessed with the MTT assay. Human cervical cancer cells (CaSki and SiHa) were injected into the flanks of nude mice.
Background: Blood vessels in tumors express higher level of aminopeptidase N (APN) compared with normal tissues. It has been reported that peptides that contain asparagine-glycine-arginine (NGR) sequence home to APN in tumor vasculature. Increased expression of APN in tumor vascular endothelium, therefore, offers an opportunity to target NGR peptide-linked therapeutic reagents to tumors.
View Article and Find Full Text PDFEndothelial cells involved in vasculogenesis and angiogenesis are key targets in cancer therapy. Recent evidence suggests that tumor cells can express some genes typically expressed by endothelial cells and form extracellular matrix-rich tubular networks, phenomena known as vasculogenic mimicry. We examined the effects of three angiogenesis inhibitors (i.
View Article and Find Full Text PDFTumor vasculatures express high levels of alphaVbeta3/alphaVbeta5 and alpha5beta1 integrins. Consequently, peptides containing the RGD (Arg-Gly-Asp) sequence, which is present in ligands of integrins, is effective in targeting therapeutic reagents to tumor vascular endothelium. In our study, we investigated whether the biologic activity of endostatin can be enhanced by the addition of an integrin targeting sequence.
View Article and Find Full Text PDFRecently, we demonstrated that the designed peptide anginex displays potent antiangiogenic activity. The aim of the present study was to investigate anginex treatment as a single-agent therapy and to test its ability to improve conventional chemotherapy and antiangiogenesis therapy. In a human ovarian carcinoma mouse model, anginex inhibited tumor growth by 70%.
View Article and Find Full Text PDFCancer therapies based on the inhibition of angiogenesis by endostatin have recently been developed. We demonstrate that a mutated form of human endostatin (P125A) can inhibit the angiogenic switch in the C3(1)/Tag mammary cancer model. P125A has a stronger growth-inhibitory effect on endothelial cell proliferation than wild-type endostatin.
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