Intermolecular Interaction of Polymer Brushes Containing Phosphorylcholine and Inverse-Phosphorylcholine.

Choline phosphate (CP) is a phosphobetaine-type zwitterionic functional group, referred to as inverse phosphorylcholine (PC) due to the reverse orientation of a positively charged quaternary amine and anionic phosphate in contrast to PC lipids in nature. The A unique dipole paring between CP and PC groups has attracted much attention in the biointerface research field. Herein, to evaluate the molecular interaction between the CP and PC groups in water, force-distance curve measurements using scanning probe microscopy (SPM) with a PC-group-functionalized cantilever was carried out on the surface of polymer brushes bearing the CP groups. Three types of methacrylate monomers bearing CP with ethyl (Et), methoxyethyl (MOE), and isopropyl (iPr) phosphates were synthesized in 42-71% yields, and polymerized by surface-initiated atom transfer radical polymerization to form polymer brushes on silicon wafers. The surface free energy of CP-polymer brushes with Et, MOE, and iPr was estimated to be 64.0, 61.4, and 57.4 mN m-1, respectively, based on contact angle measurements. Force-distance curve measurements of polymer brushes having a CP group was conducted in water at 25 °C by SPM using a spherical probe produced by attaching a silica particle (SiP; d = 25 µm) covered with PC or CP groups to a tipless cantilever. Adhesion force larger than 14 nN was observed between the CP-polymer brushes and PC-SiP, whereas PC-polymer brushes revealed extremely low adhesion force of less than 0.6 nN with PC-SiP and propylsilane-modified SiP. The specific attractive molecular interaction between CP and PC groups was quantitatively evaluated.

Increase in intracellular Ca(2+) concentrations and the corresponding intracellular acidification are early steps for induction of apoptosis by geranylgeraniol in HL60 cells.

To elucidate the mechanism of induction of apoptosis by geranylgeraniol (GGO), which is a potent inducer of apoptosis in various lines of human cancer cells, we examined the role of intracellular acidification during GGO-induced apoptosis using human leukemia HL60 cells. Flow cytometry analysis revealed that apoptosis induced in human leukemia HL60 cells by GGO was associated with intracellular acidification. Both GGO-induced intracellular acidification and apoptosis as analyzed by DNA fragmentation were inhibited by phorbol myristate acetate (TPA) and O'-bis(2-aminophenyl)ethyleneglycol-N,N,N',N-tetraacetic acid tetraacetoxymethyl ester (BAPTA-AM), an intracellular Ca(2+) chelator, but not by ethyleneglycol-bis(2-aminoethylether)-N,N,N',N'-tetraacetic acid (EGTA). These results suggest that the early concentration change of intracellular Ca(2+) and the corresponding decrease in intracellular pH are required for the induction of apoptosis in HL60 cells by GGO.

Alteration in copy numbers of genes as a mechanism for acquired drug resistance.

Chemoresistance is a major obstacle for successful treatment of cancer. To identify regions of the genome associated with acquired resistance to therapeutic drugs, we conducted molecular cytogenetic analyses of 23 cancer-cell lines, each resistant to either camptothecin, cisplatin, etoposide (VP-16), Adriamycin, or 1-beta-D-arabinofuranosylcytosine, although the parental tumor lines were not. Subtractive comparative genomic hybridization studies revealed regions of gain or loss in DNA-copy numbers that were characteristic of drug-resistant cell lines; i.e., differences from their drug-sensitive parental cell lines. Thirteen ATP-binding cassette (ABC) transporter genes [ABCA3, ABCB1 (MDR1), ABCB6, ABCB8, ABCB10, ABCB11, ABCC1 (MRP1), ABCC4, ABCC9, ABCD3, ABCD4, ABCE1, and ABCF2] were amplified among 19 of the resistant cell lines examined. Three genes encoding antiapoptotic BCL-2 proteins (BCL2L2, MCL1, and BCL2L10) were also amplified and consequently overexpressed in three of the derivative lines. Down-regulation of BCL2L2 with an antisense oligonucleotide sensitized a VP-16 resistant ovarian-cancer cell line (SKOV3/VP) to VP-16. A decrease in copy numbers of genes encoding deoxycytidine kinase, DNA topoisomerase I, and DNA topoisomerase II alpha reduced their expression levels in one cytosine arabinoside-resistant line, two of three camptothecin-resistant lines, and two of five VP-16-resistant cell lines, respectively. Our results indicated that changes in DNA-copy numbers of the genes mentioned can activate or down-regulate them in drug-resistant cell lines, and that such genomic alterations might be implicated in acquired chemoresistance.

Combined therapy using Q-switched ruby laser and bleaching treatment with tretinoin and hydroquinone for acquired dermal melanocytosis.

BACKGROUND AND OBJECTIVE: Acquired dermal melanocytosis (ADM; acquired bilateral nevus of Ota-like macules) is known for its recalcitrance compared with Nevus of Ota, and we assume that one of the reasons is a higher rate and degree of postinflammatory hyperpigmentation (PIH) seen after laser treatments. METHODS: Topical bleaching treatment with 0.1% tretinoin aqueous gel and 5% hydroquinone ointment containing 7% lactic acid was initially performed (4 to 6 weeks) to discharge epidermal melanin. Subsequently, Q-switched ruby (QSR) laser was irradiated to eliminate dermal pigmentation. Both steps were repeated two to three times until patient satisfaction was obtained (usually at a 2-month interval for laser sessions). This treatment was performed in 19 patients with ADM. Skin biopsy was performed in six cases at baseline, after the bleaching pretreatment, and at the end of treatment. RESULTS: All patients showed good to excellent clearing after two to three sessions of QSR laser treatments. The total treatment period ranged from 3 to 13 (mean of 8.3) months. PIH was observed in 10.5% of the cases. Histologically, epidermal hyperpigmentation was observed in all specimens and was dramatically improved by the topical bleaching pretreatment. CONCLUSION: QSR laser combined with the topical bleaching pretreatment appeared to treat ADM consistently with a low occurrence rate of PIH and lessen the number of laser sessions and total treatment period and may also be applied to any other lesions with both epidermal and dermal pigmentation.

Comparative analysis of apoptosis-inducing activity of codeine and codeinone.

BACKGROUND: There are relatively few studies about the antiproliferative effects of codeine-related compounds on human cancer cell lines, compared with those of morphine-related compounds. The authors previously found that codeinone, an oxidation metabolite of codeine, among 10 opioids, showed the highest cytotoxic activity (DNA fragmentation-inducing activity) against human promyelocytic leukemic cell lines (HL-60). This was counteracted by an antioxidant, N-acetyl-L-cysteine (NAC). These findings prompted us to perform a more detailed study of apoptosis induction after codeinone treatment. METHODS: Apoptosis was induced by treating HL-60 cells for 1-6 h with codeine or codeinone. DNA fragmentation was assessed by both agarose gel electrophoresis and fluorometric determination of the fragmented DNA after staining with diamidinophenylindole (DAPI). The appearance of apoptotic cells was monitored by microscopic observation after staining with Hoechst (H)-33342, and fluorescence activated cell sorter (FACS) after staining with Annexin. The release of cytochrome c and cytochrome oxidase from mitochondria and activation of caspase 3 were monitored by Western blot analysis. Intracellular caspase 3-like activity was confirmed by FACS, using cell permeable substrate. Mitochondrial manganese-containing superoxide dismutase (MnSOD) activity and mRNA expression were assayed by activity staining after separation on the polyacrylamide gel electrophoresis, and reverse transcriptase-polymerase chain reaction (RT-PCR), respectively. RESULTS: Codeinone induced internucleosomal DNA fragmentation and production of Annexin-positive apoptotic cells more potently than codeine in HL-60 cells. Codeinone stimulated the release of both cytochrome c and cytochrome oxidase, and cleavage of procaspase 3 without significant changes in both the activity and expression of MnSOD. CONCLUSIONS: Codeinone was found to possess both apoptosis and necrosis-inducing activity, in addition to the reported antinociceptive activity, further substantiating its antitumor potential.

Diverse biological activities of fermented pine seed shell extract.

Intraperitoneal administration of fermented pine seed shell extract (PSSE) (up to 2 g/kg) induced no apparent acute toxicity to mice. Pretreatment of mice with PSSE protected them from the lethality of Escherichia coli infection. PSSE showed a very weak cytotoxic activity against both normal and tumor cells and no anti-HIV activity, but stimulated the mouse macrophage-like Raw 264.7 cells to produce nitric oxide (NO) and citrulline. ESR spectroscopy showed that PSSE produced no detectable radicals, but effectively scavenged O2- (generated by the hypoxanthine-xanthine oxidase reaction), hydroxyl radical (generated by the Fenton reaction) and NO (generated by NOC-7). Comparison of PSSE with other natural products, such as polyphenols and vitamins, further confirmed the close association between radical intensity and radical scavenging activity, suggesting the bimodal action of natural products. Although the biological activities of PSSE were relatively lower than those of other natural products, the present study suggests the possible medicinal efficacy of PSSE.