• Bulletin of the Korean Chemical Society
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• v.34 no.12
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• pp.3782-3786
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• 2013

Non-small cell lung cancer (NSCLC) is the most common type of lung cancer and that accounts for 85% of lung cancer patients. Although several EGFR-targeted drugs have been developed in the treatment of NSCLC, the clinical efficacy of EGFR-targeted drugs in NSCLC is limited by the occurrence of drug resistance. In this regard, Hsp90 represents great promise as a therapeutic target of cancer due to its potential to simultaneously disable multiple signaling pathways. In this study, we discovered that a natural product, flavokawain B disrupted Hsp90 chaperoning function and impaired the growth of gefitinib-resistant non-small cell lung cancer (H1975). The result suggested that flavokawain B could serve as a potential lead compound to overcome the drug resistance in cancer chemotherapy.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.48 no.1
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• pp.11-24
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• 2022

It has been reported that the ethanolic extract of the root of Piper methysticum (P. methysticum) inhibits melanogenesis in melanocyte stimulating hormone (MSH)-activated B16 melanoma cells. Flavokawain B (FKB) and Flavokawain C (FKC) isolated from this extract have been found to inhibit melanin production based on anti-melanogenesis activity. This study was designed to find out the inhibition and its process of FKB and FKC on melanin synthesis in melan-a melanocytes. FKB and FKC inhibited melanogenesis at 10 μM, 5 μM respectively in melan-a melanocytes. However, they did not inhibit extracellular tyrosinase activity from melan-a melanocytes. FKB reduced the protein level of tyrosinase (Tyr), tyrosinase-related protein 1 (TRP-1), tyrosinase-related protein 2 (TRP-2), microphthalmia-associated transcription factor (MITF) and the mRNA level of Tyr and TRP-1. FKC reduced the protein level of TRP-2 and MITF and the mRNA level of TRP-1 and Tyr. The reduced expression of Tyr and TRP-1 might be resulted from the decreased MITF which regulates major melanogenic proteins. However, since the mRNA expression of MITF did not change by FKB and FKC treatment, the effects of FKB and FKC on extracellular signal regulating kinase (ERK)/AKT phosphorylation, known to regulate the degradation of MITF, were confirmed. FKB and FKC significantly increased the phosphorylation of ERK1/2, not in AKT. These results suggest that FKB and FKC may be helpful as a potential depigmenting agent for various hyper-pigmentary disorders.

• YAKHAK HOEJI
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• v.60 no.3
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• pp.135-140
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• 2016

Heat shock protein 90 (Hsp90) is a ubiquitous molecular chaperone, which is associated with stabilization of many oncogenic proteins for cancer cell survival. Hsp90 is overexpressed 2-10 fold higher in cancer cells than normal cells. Due to its potential to simultaneously disable multiple signaling pathway, Hsp90 has been identified as a validated target for cancer therapy. Accordingly, we designed and synthesized 2',4'-dimethoxychalcone derivatives to inhibit Hsp90 chaperone function. Among 2',4'-dimethoxychalcone derivatives, we found that compound 1g disrupted Hsp90 chaperoning function and impaired the growth of cancer cells. These findings indicated that 1g could serve a potential lead compound to target Hsp90 in cancer chemotherapy.