Shu-Jiau Chiou

Sennoside B inhibits PDGF receptor signaling and cell proliferation induced by PDGF-BB in human osteosarcoma cells.

AIMS To address the possibility that sennoside B inhibition of cell proliferation is mediated via interference with platelet-derived growth factor (PDGF) signaling. MAIN METHODS Human osteosarcoma MG63 cells were treated with PDGF in the presence or absence of sennoside B. Activation of the PDGF signaling pathway was monitored using western immunoblotting with specific antibodies against the PDGF receptor, phosphotyrosine and components of the downstream signaling cascade. Activation of cell metabolism and proliferation was assessed by chromogenic reduction of MTT. KEY FINDINGS Sennoside B was found to inhibit PDGF-BB-induced phosphorylation of the PDGF receptor (PDGFR) in human MG63 osteosarcoma cells. Downstream signaling was also affected; pre-incubation of PDGF-BB with sennoside B inhibited the phosphorylation of pathway components including Ak strain transforming protein (AKT), signal transducer and activator of transcription 5 (STAT-5) and extracellular signal-regulated kinase 1/2 (ERK1/2). Further, we found that sennoside B can bind directly to the extracellular domains of both PDGF-BB and the PDGF-beta receptor (PDGFR-beta). The effect was specific for sennoside B; other similar compounds including aloe-emodin, rhein and the meso isomer (sennoside A) failed to inhibit PDGFR activation or downstream signaling. Sennoside B also inhibited PDGF-BB stimulation of MG63 cell proliferation. SIGNIFICANCE These results indicate that sennoside B can inhibit PDGF-stimulated cell proliferation by binding to PDGF-BB and its receptor and by down-regulating the PDGFR-beta signaling pathway. Sennoside B is therefore of potential utility in the treatment of proliferative diseases in which PDGF signaling plays a central role.

Novel azulene-based derivatives as potent multi-receptor tyrosine kinase inhibitors.

A series of azulene-based derivatives were synthesized as potent inhibitors for receptor tyrosine kinases such as FMS-like tyrosine kinase 3 (FLT-3). Systematic side chain modification of prototype 1a was carried out through SAR studies. Analogue 22 was identified from this series and found to be one of the most potent FLT-3 inhibitors, with good pharmaceutical properties, superior efficacy, and tolerability in a tumor xenograft model.

The effect of doping element Zr on anisotropy and microstructure of SmCo7−xZrx

Ab initio density functional calculations, transmission electron microscope, and x-ray diffraction (XRD) were used to study the dominant factor of increased coercivity for the doping effect in SmCo7−xZrx (x = 0 to 0.3). Simulated values of saturated magnetization are 940 emu/cm3 for SmCo7 and 799 emu/cm3 for SmCo6.7Zr0.3, which agree with experimental results within 6%. The calculated anisotropy constant (for 2e) increases from 1.151 × 107 erg/cm3 for SmCo7 to 1.934 × 107 erg/cm3 for SmCo6.7Zr0.3. The grain sizes remain almost the same by adding ∼4% (atomic percent) Zr through the analyses of XRD. The increased anisotropy is the dominated factor for enhancing the coercivity in SmCo6.7Zr0.3. In addition, both results of Rietveld refinements of XRD data and ab initio calculations show that Zr situating at 2e/3g positions are more stable than 2e/2e locations, which were suggested conventionally.

Polygala tenuifolia extract inhibits lipid accumulation in 3T3-L1 adipocytes and high-fat diet–induced obese mouse model and affects hepatic transcriptome and gut microbiota profiles

ABSTRACT Obesity, the excessive accumulation of lipids in the body, is closely associated with many prevalent human disorders. Continued efforts to identify plant extracts that exhibit anti-obesity effects have drawn much attention. This study investigated whether a Polygala tenuifolia extract (PTE) possesses anti-obesity activity and how PTE may affect liver gene expression and gut microbiota. We used 3T3-L1 adipocytes and a high-fat diet–induced obese mouse model to determine the effects of PTE on lipid accumulation. Next-generation sequencing analysis of liver gene expression and gut microbiota profiles following PTE treatment were conducted to elucidate possible mechanisms. We found that treatment of fully differentiated 3T3-L1 adipocytes with PTE inhibited lipid accumulation in the cells through reducing lipid formation and triglyceride content and by increasing lipase activity. No cytotoxicity was observed from the PTE treatment. After 5 weeks of treatment with PTE, the increased body weight, elevated serum triglyceride content, and liver steatosis in the high-fat diet–induced obese mice were each reduced. Liver transcriptomic analysis revealed that expression of genes involved in lipid and cholesterol metabolism was significantly altered. The low-grade chronic inflammation of obesity caused by a high-fat diet was also decreased after PTE treatment. In addition, treatment with PTE improved the relatively low Bacteroidetes/Firmicutes ratio in the gut of high-fat diet–fed mice through enrichment of the Proteobacteria population and reduction of the Deferribacteres population. In conclusion, treatment with PTE inhibited lipid accumulation by inducing the expression of the master transcription factor PPARα, attenuated the low-grade chronic inflammation of obesity, and also altered gut microbiota profiles. These results indicate that PTE has the potential to be developed into an anti-obesity food supplement and therapy. Abbreviations: Abcg5: ATP-binding cassette subfamily G member 5; ALT: alanine aminotransferase; AMPK: adenosine monophosphate-activated protein kinase; AST: aspartate aminotransferase; B/F: Bacteroidetes to Firmicutes [ratio]; C/EBPα: CCAAT/enhancer-binding protein alpha; CR: creatinine; Cyp51: cytochrome P450 family 51; DMEM: Dulbecco’s modified Eagle’s medium; Fabp5: fatty acid-binding protein 5; FBS: fetal bovine serum; Fdps: farnesyl diphosphate synthase; Glc: Glucose; HFD: high-fat diet; GO: gene ontology; HPRT: hypoxanthine guanine phosphoribosyl transferase; IBMS: 3-isobutyl-1-methylxanthine; Idi1: isopentenyl-diphosphate delta isomerase 1; IL-1β: interleukin-1-beta; Lpin1: phosphatidic acid phosphohydrolase; LPS: lipopolysaccharide; Mvd: mevalonate diphosphate decarboxylase; ND: normal diet; OTU: operational taxonomic units; Pcsk9: proprotein convertase subtilisin/kexin 9; Pctp: phosphatidylcholine transfer protein; PPARα: peroxisome proliferator-activated receptor alpha; PPARγ: peroxisome proliferator-activated receptor gamma; PTE: Polygala tenuifolia extract; Saa1: serum amyloid A1; SD: standard deviation; SEM: standard error of the mean; Serpina12: serpin family member 12; Sqle: squalene monooxygenase; SREBP1C: sterol regulatory element-binding protein 1C; TCHO: total cholesterol; TG: triglyceride

Abstract 5781: ITRI-260, a new azaazulenone class kinase inhibitor, induces complete tumor regression and prolongs survival in AML mice

The FMS-like tyrosine kinase-3 (FLT3) is a receptor tyrosine kinase with important roles in hematopoietic stem/progenitor cell survival and proliferation. FLT3 is over-expressed in the majority of acute myeloid leukemia (AML) and the presence of FLT3 active mutations is associated with poor prognosis, implicating FLT3 as a potential target for AML treatment. ITRI-260 is a new azaazulenone class kinase inhibitor that inhibited FLT3-ITD-dependent MV4-11 cell growth with IC50 of 21 nM and cellular phosphorylation with IC50 of 17 nM. In in vivo PK study, ITRI-260 showed favorable oral PK profiles. The maximum concentration of ITRI-260 was 700 nM after a single 100 mg/kg oral dosing in mice, with dose proportional exposure from 10 to 150 mg/kg. ITRI-260 showed therapeutic efficacy in a human AML orthotopic SCID mouse model, following a 100 mg/kg/qd oral dosing regimen. The treatment group showed 100% survival of animals at day 90 after tumor cell inoculation, while the vehicle control group showed 100% mortality. In the other study, ITRI-260 also increased survival in primary tumor cell engraftment model inoculated with cells isolated from sunitinib- and sorafenib-resistant AML patient. Through hERG assay with patch clamp technology, we found higher IC50 of ITIR-260 compared with sunitinib and MLN-518, which indicates that ITRI-260 might arise less cardiotoxic concern. In a 14-day subchronic toxicology study in mice, ITRI-260 was generally tolerated at 300 mg/kg/qd. The most prominent adverse effect appeared at 600 mg/kg/qd group is starry sky appearance in spleen, which is moderate and reversible. No specific clinical signs or body weight loss were attributed to the test article. In conclusion, the in vitro/in vivo PK/PD/toxicology studies have provided the basis for the clinical developmental potential of ITRI-260 in AML. The bridge studies from discovery to development such as CMC, GLP toxicology/safety pharmacology and pre-formulation are now in progress. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 5781.

Abstract LB-160: ITRI-260, a promising candidate for treatment of acute myeloid leukemia

Proceedings: AACR 101st Annual Meeting 2010‐‐ Apr 17‐21, 2010; Washington, DC Acute myeloid leukemia (AML) is a highly malignant hematopoietic tumor characterized by an abnormal proliferation of myeloid progenitor cells, decreased rate of self-destruction and an arrest in cell differentiation. The internal tandem duplication mutations of FMS-like tyrosine kinase-3 (FLT3/ITD mutations) are common in AML and linked to poor prognosis. ITRI-260 generated from designed by computer-assisted rationale drug design and in silico prioritized approaches, was proved to be a potent cell growth inhibitor against FLT3/ITD mutated AML cells through FLT3 and c-Kit inhibition. The in vivo efficacy of ITRI-260 via oral route was demonstrated in MV4-11 xenograft mice model. Besides, two more orthotopic murine models were used to assess the in vivo therapeutic efficacy of ITRI-260. The first one is MV4-11 cell orthotopically engraft into NOD/SCID mice bone marrow and the second one is primary AML cells from AML patient engraft into NOD/SCID mice bone marrow. The results show that ITII-260 can decrease FLT3/ITD mutant leukemia blasts in peripheral blood and bone marrow in both animal models. Finally, ITRI-260 prolongs the survival in both bone marrow engraft mice models. These findings strongly suggest clinical benefits of ITRI-260 in patients with FLT3/ITD AML. Currently we are planning the bridged projects to push ITRI-260 toward IND status. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr LB-160.