Ethacrynic Acid Inhibits Sphingosylphosphorylcholine-Induced Keratin 8 Phosphorylation and Reorganization via Transglutaminase-2 Inhibition.

Sphingosylphosphorylcholine (SPC) is significantly increased in the malicious ascites of tumor patients and induces perinuclear reorganization of keratin 8 (K8) filaments in PANC-1 cells. The reorganization contributes to the viscoelasticity of metastatic cancer cells resulting in increased migration. Recently, we reported that transglutaminase-2 (Tgase-2) is involved in SPC-induced K8 phosphorylation and reorganization.

Novel suppressive effects of cardamonin on the activity and expression of transglutaminase-2 lead to blocking the migration and invasion of cancer cells.

Aims: Alpinia katsumadai was recently found in our previous study to have anti-migratory and anti-invasion activities against HT-1080 cells. However, the study did not demonstrate the exact component of Alpinia katsumadai with anti-migratory and anti-invasive activities. We tested the effects and relevant mechanism of cardamonin (CDN) on the migration and invasion of cancer cells.

Momordin I, an inhibitor of AP-1, suppressed osteoclastogenesis through inhibition of NF-kappaB and AP-1 and also reduced osteoclast activity and survival.

Osteoclasts originating from hematopoietic precursor cells differentiate into multinucleated cells through multiple steps. The essential roles of NF-kappaB and AP-1 in osteoclast differentiation have been clearly demonstrated in numerous studies. c-Fos, a component of AP-1 transcription factor, plays a key role in osteoclast differentiation.

Negative regulation of beta-catenin/Tcf signaling by naringenin in AGS gastric cancer cell.

Functional activation of beta-catenin/Tcf signaling plays an important role in early events in carcinogenesis. We examined the effect of naringenin against beta-catenin/Tcf signaling in gastric cancer cells. Reporter gene assay showed that naringenin inhibited beta-catenin/Tcf signaling efficiently.

Determination of the dissociation constants for recombinant c-Myc, Max, and DNA complexes: the inhibitory effect of linoleic acid on the DNA-binding step.

c-Myc, the protein product of protooncogene c-myc, functions in cell proliferation, differentiation, and neoplastic disease. In this study, recombinant c-Myc and Max proteins, encompassing DNA binding (basic region) and dimerization (helix-loop-helix/leucine zipper) domain of human origin, were expressed in bacteria as Myc87 and Max85. Myc87 was purified under denatured conditions and was renatured again.

Ionomycin downregulates beta-catenin/Tcf signaling in colon cancer cell line.

Functional activation of beta-catenin/Tcf signaling plays an important role in the early events in colorectal carcinogenesis. We examined the effect of ionomycin against beta-catenin/Tcf signaling in colon cancer cells. Reporter gene assay showed that ionomycin inhibited beta-catenin/Tcf signaling efficiently.

Inhibition of beta-catenin-mediated transactivation by flavanone in AGS gastric cancer cells.

Recently, data which prove that Wnt pathway activation may be an early event in multistep carcinogenesis in the stomach have been accumulating. We examined the effect of flavanone against beta-catenin/Tcf signaling in AGS gastric cancer cells. Reporter gene assay showed that flavanone inhibited beta-catenin/Tcf signaling efficiently.

Determination of binding constant of transcription factor myc-max/max-max and E-box DNA: the effect of inhibitors on the binding.

The truncated myc and max proteins, only containing basic regions and helix-loop-helix/zipper (b/HLH/Zip) regions were over-expressed in E. coli and used for the determination of the binding constant and of the inhibitory mechanism on myc-max (or max-max)-DNA complex formation. The association kinetic constants (k(1) and k(-1)) of truncated max-max or myc-max dimer and DNA were determined as k(1)=(1.