R(+)-alpha lipoic acid (RALA) is one of the cofactors for mitochondrial enzymes and, therefore, plays a central role in energy metabolism. RALA is unstable when exposed to low pH or heat, and therefore, it is difficult to use enantiopure RALA as a pharma- and nutra-ceutical. In this study, we have aimed to stabilize RALA through complex formation with cyclodextrins (CDs). α-CD, β-CD and γ-CD were used for the formation of these RALA-CD complexes. We confirmed the complex formation using differential scanning calorimetry and showed by using HPLC analysis that complexed RALA is more stable than free RALA when subjected to humidity and high temperature or acidic pH conditions. Scanning electron microscopy studies showed that the particle size and shape differed depending on the cyclodextrin used for complexation. Further, the complexes of CD and RALA showed a different particle size distribution pattern compared with that of CD itself or that of the physical mixture of RALA and CD.

To investigate the cellular/molecular mechanisms of nickel (Ni) tolerance in high‐biomass‐producing plants, we selected a Ni‐tolerant (NIT) cell line from tobacco (Nicotiana tabacum L. cv. bright yellow‐2) suspension culture. Examination of response to various abiotic stresses showed that the NIT cells acquired remarkable tolerance to excess Ni, Cu, and Al but not to the other stresses. That the NIT cells accumulated approximately 2 mM Ni under the 700 µM Ni condition suggests that the NIT cells can hyperaccumulate Ni and possess internal detoxification mechanisms for Ni. Two different sizes of putative β‐d‐xylosidase were constitutively secreted by the NIT cells, and the NIT cells showed greater elongation than the wild‐type (WT) cells. Oxalate, citrate, 2‐oxoglutarate, and glutamate contents were constitutively two‐ or three‐fold higher in the NIT cells than in the WT cells, and histidine content was increased by up to three‐fold in the NIT cells exposed to 700 µM Ni compared to those in the WT cells. Newport green DCF diacetate (NPG), a Ni‐specific fluorescence indicator, enabled the visualization of the subcellular localization of Ni in both WT and NIT cells. The NPG fluorescence was localized mainly in the vacuoles regardless of the WT or NIT cells under excess Ni conditions. The transport of Ni‐organic acids and/or Ni‐histidine complex into the vacuoles might be an important mechanism contributing to the high Ni tolerance of and the hyperaccumulation of Ni by the NIT cells.

(H.I.) 1. These authors contributed to this work equally. Word count: 4,388 ABSTRACTSex determining region Y-box 2 (SOX2) is well known as one of the "stemness" factors and is often expressed in cancers including breast cancer. In this study, we developed a reporter system using fluorescent protein driven by the promoter for SOX2 gene to detect and isolate living SOX2-positive cells. Using this system, we determined that SOX2 promoter activities were well correlated with SOX2 mRNA expression levels in 5 breast cancer cell lines, and that the cell population with positive SOX2 promoter activity (pSp-T + ) isolated from one of the 5 cell lines, MCF-7 cells, showed a high SOX2 protein expression and high sphere-forming activity compared with very low promoter activity (pSp-T low/-). The pSp-T + population expressed higher mRNA levels of several stemness-related genes such as CD44, ABCB1, NANOG and TWIST1 than the pSp-T low/-population whereas the two populations expressed CD24 at similar levels. These results suggest that the cell population with SOX2 promoter activity contains cancer stem cell (CSC)-like cells which show different expression profiles from those of CSC-marker genes previously recognized in human breast cancers.

In this study, we examined the effects of hypoxia on the malignancy of human malignant pleural mesothelioma (MPM) cell lines, and found 1) hypoxia enhanced motility and invasiveness of human malignant pleural mesothelioma (MPM) cells; 2) this phenomenon resulted from increased expression of sialylated MUC1 through the activation of HIF-1 pathway; 3) two HIF-binding sites located in the promoter region of MUC1 were important for MUC1 transactivation under hypoxia. These findings are useful for better understanding molecular mechanisms of aggressive behavior of MPM cells and for targeting them in the clinical therapies for MPM patients.

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