• 생명과학회지
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• 제12권4호
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• pp.469-476
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• 2002

남미지역에 서식하는 Tabebuia avellanedae의 수피에서 동정된 천연 quinone계 물질인 $\beta$-lapachone은 DNA topoisomerase I 억제제 이외 다양한 약리학적 기능이 있을 것으로 추정되지만 그 기능이 명확하지 않다. $\beta$-lapachone의 생리활성 기전 해석의 일환으로 본 연구에서는 인체 전립선 DU-145 암세포주의 성장에 미치는 $\beta$-lapachone의 영향을 조사하였다. p-lapachone이 함유된 배지에서 자란 암세포들은 $\beta$-lapachone 처리 농도 의존적으로 성장이 억제되었으며, 이는 apoptosis가 유발된 세포에서 특징적으로 관찰되는 chromatin condensation 및 DNA fragmentation 현상을 유발하였고, DNA flow cytometry 분석결과 apoptotic-sub Gl기에 해당하는 세포들의 빈도도 증가되었다. 또한 poly (ADP-ribose) polymerase 및 $\beta$-catenin 단백질의 발현에서도 apoptosis 유발 특이적인 분해 현상을 보여주었으며, DU-145 전립선 암세포에서 $\beta$-lapachone에 의한 이러한 apoptosis의 유발에는 Bax의 발현증가에 따른 Bcl-2 발현의 감소가 중요한 역할을 할 고 있는 것으로 사료된다.

• 생명과학회지
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• 제21권10호
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• pp.1494-1499
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• 2011

${\beta}$-lapachone은 남미에 자생하는 lapacho 나무(Tabeuia avellanedae)의 수액에 함유된 quinone계열의 일종으로 많은 인체암세포에서 apoptosis를 유발하는 것으로 알려져 있다. 본 연구는 A549 인체폐암세포를 대상으로 ${\beta}$-lapachone에 의한 apoptosis 유발 과정에서 나타나는 또 다른 현상들을 조사하기 위하여 실시되었다. ${\beta}$-lapachone이 처리된 A549 세포는 처리 농도의 증가에 따라 생존율이 감소되었으며, 이는 apoptosis 유발과 연관이 있음을 MTT assay와 flow cytometry 분석을 통하여 확인하였다. ${\beta}$-lapachone에 의한 A549 세포의 증식억제는 종양억제유전자 p53과 cyclin-dependent kinase 저해제인 p21의 발현을 전사 및 번역 수준에서 증가시켰으며, p53 단백질의 인산화 증가와 연관성이 있었다. 또한 ${\beta}$-lapachone은 caspase-3과 -9를 활성화시켰으며, 활성화된 caspase-3의 기질 단백질들[poly(ADP-ribose) polymerase, ${\beta}$-catenin 및 phospholipase C-$\gamma$1]의 단편화를 유도하였다. 아울러 ${\beta}$-lapachone은 cyclooxygenase (COX)-2의 mRNA 및 단백질의 발현을 억제하였으나 COX-1의 발현에는 영향을 미치지 않았으며, ${\beta}$-lapachone에 의한 COX-2의 발현억제는 prostaglandin E2의 생성 저하에 관련이 있었다. 본 연구의 결과는 ${\beta}$-lapachone의 항암활성 기전의 이해와 더불어 ${\beta}$-lapachone이 폐암세포에서 강력한 항암활성이 있음을 보여 주는 것이다.

• 생명과학회지
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• 제17권9호통권89호
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• pp.1298-1302
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• 2007

${\beta}-lapachone$은 남미지역에서 자생하는 Tabebuia avellanedae라는 나무의 수피에서 동정된 quinone계 물질로서 다양한 인체암세포에서 항암효과가 있는 것으로 알려져있다. 본 연구에서는 ${\beta}-lapachone$의 암 전이 억제에 대한 연구의 일환으로 HepG2 및 Hep3B 인체 간암 세포의 전이관련 유전자의 발현에 미치는 ${\beta}-lapachone$의 영향을 조사하였다. MTT assay 및 세포형태변화 관찰 결과에서 ${\beta}-lapachone$ 처리에 따라 HepG2와 Hep3B 세포들은 ${\beta}-lapachone$ 농도 의존적으로 세포의 증식이 억제되었으며 그 형태적 변형도 동반하였다. ${\beta}-lapachone$처리에 의한 암 전이 지표가 되는 IGF-lR, Tjs (ZO-1, claudin-3,-4) 및 Tj 조절인자(${\beta}-catenin$)의 발현을 RT-PCR과 Western blot analysis를 통하여 확인한 결과 ${\beta}-lapachone$ 처리가 IGF-1R의 발현 억제와 Tj 유전자 발현의 증가를 유도함으로써 ${\beta}-lapachone$이 Tj를 강화하여 암세포의 전이 억제작용을 하는 것으로 관찰 되었다. 이상의 결과는 인체 간암세포에서 ${\beta}-lapachone$의 항전이 작용의 이해에 중요한 기초 자료가 될 것으로 생각한다.

• 생명과학회지
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• 제15권3호
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• pp.323-331
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• 2005

남미지역에서 자생하는 Tabebuia avellanedae라는 나무의 수피에서 동정된 quinone계 물질이며, DNA topoisomeras억제제로 알려진 $\beta-lapachone$의 항암작용에 관한 부가적인 자료를 얻기 위하여 인체 간암(HepG2) 및 방광암(T24)세포를 대상으로 조사한 결과 다음과 같은 결과를 얻게 되었다. MTT assay 및 flow cytometry 분석 등의 결과에서, $\beta-lapachone$의 처리에 따라 조사된 두 가지 암세포에서 $\beta-lapachone$처리 농도의존적으로 암세포의 심한 형태적 변형이 동반되면서 암세포의 증식이 억제되었으며, 생존율이 저하되었고 이는 apoptosis유발과 상관성이 있음을 알 수 있었다. $\beta-lapachone$처리에 의한 두 암세포의 증식억제는 종양억제 유전자 p53 및 Cdk inhibitor p21의 발현과는 큰 연관성이 없음을 RT-PCR 및 Western blot analysis를 통하여 확인하였다. 그러나 전사조절인자 Sp-1 및 세포증식 주요조절인자인 PCNA의 단백질 발현은 $\beta-lapachone$처리에 따라 매우 감소되었으며, telomere조절에 중요한 인자들의 선택적 발현 저하 현상도 관찰되었다. 이상의 결과들은 인체 암세포에서 $\beta-lapachone$의 항암작용을 이해하는 중요한 자료가 될 것이며, $\beta-lapachone$과 유사한 화학적 구조 및 성질을 가지는 항암제 후보물질들의 항암기전 비교 및 항암제 개발을 위한 기초 자료로서 응용될 것이다.

• Biomolecules & Therapeutics
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• 제23권3호
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• pp.296-300
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• 2015

${\beta}$-Lapachone has drawn increasing attention as an anti-inflammatory and anti-cancer drug. However, its oral bioavailability has not been yet assessed, which might be useful to develop efficient dosage forms possibly required for non-clinical and clinical studies and future market. The aim of the present study was thus to investigate pharmacokinetic properties of ${\beta}$-lapachone as well as its first-pass metabolism in the liver, and small and large intestines after oral administration to measure the absolute bioavailability in rats. A sensitive HPLC method was developed to evaluate levels of ${\beta}$-lapachone in plasma and organ homogenates. The drug degradation profiles were examined in plasma to assess the stability of the drug and in liver and intestinal homogenates to evaluate first-pass metabolism. Pharmacokinetic profiles were obtained after oral and intravenous administration of ${\beta}$-lapachone at doses of 40 mg/kg and 1.5 mg/kg, respectively. The measured oral bioavailability of ${\beta}$-lapachone was 15.5%. The considerable degradation of ${\beta}$-lapachone was seen in the organ homogenates but the drug was quite stable in plasma. In conclusion, we suggest that the fairly low oral bioavailability of ${\beta}$-lapachone may be resulted from the first-pass metabolic degradation of ${\beta}$-lapachone in the liver, small and large intestinal tracts and its low aqueous solubility.

• BMB Reports
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• 제36권2호
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• pp.223-229
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• 2003

The product of a tree (Tabebuia avellanedae) from South America, $\beta$-lapachone, is known to exhibit various pharmacological properties, the mechanisms of which are poorly understood. The aim of the present study was to further elucidate the possible mechanisms by which $\beta$-lapachone exerts its anti-proliferative action in cultured human prostate cancer cells. We observed that the proliferation-inhibitory effect of $\beta$-lapachone was due to the induction of apoptosis, which was confirmed by observing the morphological changes and cleavage of the poly(ADP-ribose) polymerase protein. A DNA flow cytometric analysis also revealed that $\beta$-lapachone arrested the cell cycle progression at the G1 phase. The effects were associated with the down-regulation of the phosphorylation of the retinoblastoma protein (pRB) as well as the enhanced binding of pRB and the transcription factor E2F-1. Also, $\beta$-lapachone suppressed the cyclindependent kinases (Cdks) and cyclin E-associated kinase activity without changing their expressions. Furthermore, this compound induced the levels of the Cdk inhibitor $p21^{WAF1/CIP1}$ expression in a p53-independent manner, and the p21 proteins that were induced by $\beta$-lapachone were associated with Cdk2. $\beta$-lapachone also activated the reporter construct of a p21 promoter. Overall, our results demonstrate a combined mechanism that involves the inhibition of pRB phosphorylation and induction of p21 as targets for $\beta$-lapachone. This may explain some of its anticancer effects.

• 동의생리병리학회지
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• 제19권3호
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• pp.722-728
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• 2005

The DNA topoismerase I inhibitor ${\beta}-lapachone$, the product of a lapacho tree (Tabebuia avellanedae) from South America, activates a novel apoptotic response in a number of cell lines. In the present report, we investigated the effects of ${\beta}-lapachone$ on the growth of human lung in human non-small-cell-lung-cancer A549 cells. Upon treatment with ${\beta}-lapachone$, a concentration-dependent inhibition of cell viability and cell proliferation was observed as measured by hemocytometer counts and MTT assay. The ${\beta}-lapachone-treated$ cells developed many of the hallmark features of apoptosis, including membrane shrinking, condensation of chromatin and DNA fragmentation. These apoptotic effects of ${\beta}-lapachone$ in A549 cells were associated with a marked induction of pro-apoptotic Bax expression, however the levels of anti-apoptotic Bcl-2 expression were decreased in a dose-dependent manner. Accordingly, elevated amount of cyclin-dependent kinase inhibitor p21 expression accompanied by up-regulation of tumor suppressor p53 was observed. By RT-PCR analyses, decrease in gene expression level of telomerase reverse transcriptase and telomeric repeat binding factor were also observed. Thus, these findings suggest that ${\beta}-lapachone$ may be a potential anti-cancer therapeutics for the control of human lung cancer cell model.

• Biomolecules & Therapeutics
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• 제22권3호
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• pp.184-192
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• 2014

${\beta}$-lapachone is a naturally occurring quinone that selectively induces apoptotic cell death in a variety of human cancer cells in vitro and in vivo; however, its mechanism of action needs to be further elaborated. In this study, we investigated the effects of ${\beta}$-lapachone on the induction of apoptosis in human gastric carcinoma AGS cells. ${\beta}$-lapachone significantly inhibited cellular proliferation, and some typical apoptotic characteristics such as chromatin condensation and an increase in the population of sub-G1 hypodiploid cells were observed in ${\beta}$-lapachone-treated AGS cells. Treatment with ${\beta}$-lapachone caused mitochondrial transmembrane potential dissipation, stimulated the mitochondria-mediated intrinsic apoptotic pathway, as indicated by caspase-9 activation, cytochrome c release, Bcl-2 downregulation and Bax upregulation, as well as death receptor-mediated extrinsic apoptotic pathway, as indicated by activation of caspase-8 and truncation of Bid. This process was accompanied by activation of caspase-3 and concomitant with cleavage of poly(ADP-ribose) polymerase. The general caspase inhibitor, z-VAD-fmk, significantly abolished ${\beta}$-lapachone-induced cell death and inhibited growth. Further analysis demonstrated that the induction of apoptosis by ${\beta}$-lapachone was accompanied by inactivation of the phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathway. The PI3K inhibitor LY29004 significantly increased ${\beta}$-lapachone-induced apoptosis and growth inhibition. Taken together, these findings indicate that the apoptotic activity of ${\beta}$-lapachone is probably regulated by a caspase-dependent cascade through activation of both intrinsic and extrinsic signaling pathways, and that inhibition of the PI3K/Akt signaling may contribute to ${\beta}$-lapachone-mediated AGS cell growth inhibition and apoptosis induction.

• Bulletin of the Korean Chemical Society
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• 제32권1호
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• pp.153-156
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• 2011

A concise synthesis of (${\pm}$)-rhinacanthin A is achieved in two steps by epoxidation of dehydro-$\alpha$-lapachone, followed by chemo- and regioselective reduction. Dehydro-$\alpha$-lapachone was also synthesized in two steps starting from 4-methoxy-1-naphthol by ethylenediamine diaetate (EDDA)-catalyzed benzopyran formation and a CAN-mediated oxidation reaction. $\beta$-Lapachone was synthesized in three steps from 4-methoxy-1-naphthol by benzopyran formation, catalytic hydrogenation, and Jones oxidation. As additional reactions, synthesis of pyranonaphthoquinone derivatives with the pyranokunthone B skeleton has been achieved in a single step from readily available 2-hydroxy-6-methoxy-1,4-naphthoquinone and 2-hydroxy-7-methoxy-1,4-naphthoquinone.

• Animal cells and systems
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• 제5권4호
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• pp.267-274
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• 2001

Calpains are a family of cysteine proteases existing primarily in two forms designated by the $Ca^{2+}$ concentration needed for activation in vitro, $\mu$-calpain (calpain-I) and m-calpain (calpain-II). The physiologica1 roles of calpains remain unclear. Many groups have proposed a role for calpains In apoptosis, but their patterns of activation are not well characterized. Calpains have been implicated in neutrophil apoptosis, glucocorticoid-induced thymocyte apoptosis, as well as many other apoptotic pathways. Calpain activation in apoptosis is usually linked upstream or downstream to caspase activation, or in a parallel pathway alongside caspase activation. Calpains have been suggested to be involved in DNA fragmentation (via endonuclease activation), but also as effector proteases that cleave cellular proteins involved in DNA repair, membrane associated proteins and other homeostatic regulatory proteins. Recently, our laboratory demonstrated $\mu$-calpain activation in NAD(P)H: quinone oxidoreducatse 1 (NQO1)-expressing cells after exposure to $\beta$-lapachone, a novel quinone and potential chemo- and radio-therapeutic agent. Increased cytosolic $Ca^{2+}$ in NQO1-expressing cells after $\beta$-lapachone exposures were shown to lead to $\mu$-calpain activation. In turn, $\mu$-calpain activation was important for substrate proteolysis and DNA fragmentation associated with apoptosis. Upon activation, $\mu$-calpain translocated to the nucleus where it could proteolytically cleave PARP and p53. We provided evidence that $\beta$-lapachone-induced, $\mu$-calpain stimulated, apoptosis did not involve any of the known caspases; known apoptotic caspases were not activated after $\beta$-lapachone treatment of NQO1-expressing cells, nor did caspase inhibitors have any effect on $\beta$-1apachone-induced cell death. Elucidation of processes by which $\beta$-1apachone-stimulated $\mu$-calpain activation and calpains ability to activate endonucleases and induce apoptosis independent of caspase activity will be needed to further develop/modulate $\beta$-lapachone for treatment of human cancers that over-express NQO1.