Protecting future antimalarials from the trap of resistance:Lessons from artemisinin-based combination therapy(ACT)failures / 药物分析学报

Having faced increased clinical treatment failures with dihydroartemisinin-piperaquine(DHA-PPQ),Cambodia swapped the first line artemisinin-based combination therapy(ACT)from DHA-PPQ to artesunate-mefloquine given that parasites resistant to piperaquine are susceptible to mefloquine.However,triple mutants have now emerged,suggesting that drug rotations may not be adequate to keep resistance at bay.There is,therefore,an urgent need for alternative treatment strategies to tackle resistance and prevent its spread.A proper understanding of all contributors to artemisinin resistance may help us identify novel strategies to keep artemisinins effective until new drugs become available for their replacement.This review highlights the role of the key players in artemisinin resistance,the current strategies to deal with it and suggests ways of protecting future antimalarial drugs from bowing to resistance as their predecessors did.

Effect of 12-O-tetradecanoylphorbol 13-acetate (TPA) on the Expression of Keratin in HaCaT Cells / 대한해부학회지

In human skin, specific keratin markers reflect on normal differentiation and pathologic conditions. This experiment focused on the expressional pattern of keratin 10 (K10: normal differentiation marker), and keratin 8 & 13 (K8 & K13: pathologic differentiation marker) together with their cellular localization after treating HaCaT cells with 12-Otetradecanoylphorbol 13-acetate (TPA). The cells were treated with TPA at 0, 0.1, 1 microgram/ml for 2 hours or 6 hours. Morphologic studies revealed that TPA treatment changed the shape of cells into the fibroblast-like cells with highly folded nuclear membrane and reduced number of the desmosome. The results of indirect immunofluorescent staining and Northern blotting analysis showed that TPA considerably down-regulated the expression of K10, while markedly up-regulating the expression of K8 and K13 both at protein and mRNA levels. Furthermore, by simultaneous staining for keratins and DNA content in flow cytometry, it was found that TPA increased the expression of K8 and K13 dramatically at the S-G2-M phase of the cells. In conclusion, these changes induced by TPA in HaCaT cells may indicate a close relationship between the morphologic change and the altered expression of keratin subfamilies. It also suggests that TPA known as a tumor promotor may directly induce the potentially malignant cells even without the support of tumor initiator.

Change in Expression of Keratin and Proto-oncogene Induced by Beta-propiolactone in HaCaT Cell / 대한해부학회지

To investigate the relationship between the morphologic changes and the expression of keratin and proto-oncogene induced by Beta-propiolactone (BPL), we assessed on the expression of keratins (K8, K10, K13) and proto-oncogenes (c-fos, c-jun, c-myc) in human HaCaT cell line. The cells were treated with 0, 0.1, 1 microgram/ml BPL for 2 or 6 hours. Morphologic studies revealed that BPL changed the cells into fibrocyte-shaped, caused highly lobulated nuclei and reduced desmosomes in their number. Findings of immunofluorescence and Northern blotting indicated that BPL consistently decrease expression of K10 representing a normal differentiation marker of keratinocytes, while increasing expression of K8 and K13 associated with a pathologic differentiation. This reagent also up-regulated expression of c-fos and c-jun, and down-regulated expression of c-myc. Together with staining for each keratin or proto-oncogene and DNA content in flow cytometry, BPL increased K8 expression dramatically at S-G2-M phase. The induction of c-Fos at S-G2-M phase appeared within 2 hours, and c-Jun gradually occurred. However, c-Myc was inhibited regardless of phases of cell cycle. In conclusion, these changes caused by BPL demonstrate a close relationship between the morphologic evidence and the altered expression of each keratin and proto-oncogene.

Expression of kringle 1-3 domain fragment of human plasmihogen in E.coli and the anti-tumor activity of its product / 中国免疫学杂志

Objective:To study the expression of kringle 1-3 domain fragment of human plasmihogen in E.coli and the anti-tumor activity of its product.Methods:The K1-3 domain fragment was cloned in expression vector pBV220,the resulted recombinant plasmid pBV-K13 was transformed into E.coli DH5? and its product was purified and assayed its bioactivity.Results:K1-3 domain fragment was expressed in(E.coli) DH5?.The results showed the expressed product covered 20% of the total bacterial protein on SDS-PAGE and the Western blot analysis showed that the product had immunological specificity with the antiserum of human plasminogen and inhibits the growth of chorioallantoic membrane(CAM) angiogenesis and mouse B16 melanoma.Conclusion:Human plasminogen K1-3 domain fragment was expressed in E.coli;the expressed product has anti-angiogenesis and anti-tumor activity.