• Asian Pacific Journal of Cancer Prevention
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• v.17 no.12
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• pp.5185-5188
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• 2016

Objective: Targeted-drug-delivery based lipid nanoparticles has emerged as a new and effective approach in cancer chemotherapy. Here, we investigated the ability of folate-modified nanostructured lipid carriers (NLCs) to enhance letrozol (LTZ) efficacy in MCF-7 breast cancer cells. Methods: New formulations were evaluated regarding to particle size and scanning electron microscope (SEM) features. Anti-proliferative effects of LTZ loaded nanoparticles were examined by MTT assay. To understand molecular mechanisms of apoptosis and cell cycle progression, flow cytometric assays were applied. Results: Optimum size of nanoparticles was obtained in mean average of $98{\pm}7nm$ with a poly dispersity index (PDI) of 0.165. The IC50 value was achieved for LTZ was $2.2{\pm}0.2{\mu}M$. Folate-NLC-LTZ increased the percentage of apoptotic cells from 24.6% to 42.2% compared LTZ alone (p<0.05). Furthermore, LTZ loaded folate targeted NLCs caused marked accumulation of cells in the subG1 phase. Conclusion: Taken together, our results concluded that folate targeted LTZ can be considered as potential delivery system which may overcome limitations of clinical application of LTZ and improve drug efficacy in tumor tissue.

• Korean Journal of Microbiology
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• v.28 no.1
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• pp.35-40
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• 1990

The restriction clevage map of multi-copy recombinant plasmid, pJY712(8.1kb), carrying the thiostrepton resistance gene(tsr) was determined. pJY712 had a broad host range in Streptomyces and contained single BglII site for cloning purpose. The plasmid showed the phenomenon of lethal zygosis ($Ltz^{+}$). Transformation frequency of pJY712 was $5.0\times 10^{4}$ transformants per ug plasmid DNA (TFU) in S. lividans. Plasmid pJY713 was constructed by inserting the tyrosinase gene(mel) into the BclI site of pJY712. Recombinant plasmid pJY714 carrying the mel gene was constructed by in vitro deletion of a segment (1.9kb BglII-BclI fragment) from pJY713.