• 대한의생명과학회지
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• 제13권2호
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• pp.75-81
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• 2007

Sodium salicylate (NaSal), a chemopreventive drug, has been shown to induce apoptosis and cell circle arrest depending on its concentrations in a variety of cancer cells. In A549 cells, low concentration of NaSal (5$\sim$10 mM) induces cell cycle arrest, whereas it induces apoptosis at higher concentration of 20 mM. In the present study, we examined the molecular mechanism for NaSal-induced cell cycle arrest. NaSal induced expression of p53, p21 (Wafl/Cipl), and p27 (Kipl) that play important roles in cell cycle arrest. p53 induction was mediated by its phosphorylation at Ser-15 that could be prevented by the PI3K-related kinase (ATM, ATR and DNA-PK) inhibitors including wortmannin, caffeine and LY294002. In addition, NaSal-induction of p2l (Wafl/Cipl) was detected in P53 (+/+) wild type A549 cells but not in p53 (-/-) mutant H1299 cells, indicating p53-dependent p21 (Wafl/Cipl) induction. In contrast, p27 (Kipl) that is a negative regulate. of cell cycle with p21 (Wafl/Cipl) was observed both in A549 cells and H1299 cells. Thus, 5 mM NaSal appeared to cause cell cycle arrest through inducing the cyclin-dependent kinase inhibitor p21 (Wafl/Cipl) via PI3K-related protein kinase-dependent p53 activation as well as by up-regulating p27 (Kipl) independently of p53 in A549 cells.

• 생명과학회지
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• 제27권12호
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• pp.1507-1514
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• 2017

김치는 한국에서 가장 인기 있는 발효식품이며, 여러 연구에서 암예방, 항비만, 항염증 등의 활성을 가지는 건강기능성 식품으로 보고되고 있다. 본 실험에서는 김치의 기능성을 높이기 위하여 항암기능성이 알려진 겨우살이 추출물을 첨가하여 개발한 암환자용 김치(kimchi B)의 암세포 증식억제능 및 그 기전에 대하여 검토하였다. 인체 폐암 A549세포를 이용하여 증식저해 효과와 apoptosis 유도 및 관련된 mRNA 유전자 발현에 미치는 영향을 관찰하였으며, 대조군으로는 표준화김치(kimchi A)를 사용하였다. A549 인체 폐암 세포를 이용한 성장 저해시험에서 MTT 방법과 hemocytometer를 이용하여 암세포 수를 개수한 결과, 김치를 첨가한 군에서 농도 의존적으로 증식억제 효과가 나타났으며, 특히 kimchi B를 첨가한 군에서 더 높은 증식억제 효과를 확인할 수 있었다. DAPI 염색을 통해 암세포 핵의 형태적 특징을 조사한 결과 kimchi B를 첨가한 군에서 DNA단편이 발견되어, A549 인체 폐암세포의 증식억제효과는 apoptosis에 의한 것으로 관찰되었다. Apoptosis의 기전을 알아보기 위하여 Bcl-2 family (Bax, Bcl-2, Bcl-xL) 발현과 p53, p21 발현을 측정한 결과, kimchi B를 첨가한 군에서 Bax 유전자는 증가하고 Bcl-2 유전자 발현이 감소하여, 이들 유전자 발현과 관련되어 apoptosis가 유도되었음을 확인할 수 있었으며, 이들 유전자들의 발현은 p21 발현 증가에 의한 것으로 보아 kimchi B를 처리한 A549인체 폐암세포는 p53 비의존적인 p21 발현증가에 의해 암세포 증식저해 효과를 나타낸 것으로 사료된다. 이 연구를 바탕으로 암환자들을 위한 기능성이 증진된 김치 개발에 활용이 가능할 것으로 기대된다.

• 동의생리병리학회지
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• 제19권1호
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• pp.167-173
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• 2005

To investigate the possible molecular mechanism (s) of bee venom as a candidate of anti-cancer drug, we examined the effects of the compound on the growth of human lung carcinoma cell line A549. Bee venom treatment declined the cell growth and viability of A549 cells in a concentration-dependent manner, which was associated with induction of apoptotic cell death. Bee venom down-regulated the levels of anti-apoptotic genes such as Bcl-2 and Bcl-XS/L, however, the levels of Bax, a pro-apoptotic gene, were up-regulated. Bee venom treatment induced not only tumor suppressor p53 but also cyclin-dependent kinase inhibitor p21WAF1/CIP1 expression in a dose-dependent manner. Furthermore, bee venom treatment induced the down-regulation of telomerase reverse transcriptase mRNA and telomeric repeat binding factor expression of A549 cells, however, the levels of telomerase-associated protein-1 and c-myc were not affected. Taken together, these findings suggest that bee venom-induced inhibition of human lung cancer cell growth is associated with the induction of apoptotic cell death via regulation of several major growth regulatory gene products, and bee venom may have therapeutic potential in human lung cancer.

• Biomolecules & Therapeutics
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• 제20권2호
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• pp.177-182
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• 2012

Tetrazolium violet is a tetrazolium salt and has been proposed as an antitumor agent. In this study, we reported for the first time that tetrazolium violet not only inhibited human lung cancer A549 cell proliferation but also induced apoptosis and blocked cell cycle progression in the G1 phase. The results showed that tetrazolium violet significantly decreased the viability of A549 cells at $5-15{\mu}M$. Tetrazolium violet -induced apoptosis in A549 cells was confirmed by H33258 staining assay. In A549, tetrazolium violet blocked the progression of the cell cycle at G1 phase by inducing p53 expression and further up-regulating p21/WAF1 expression. In addition, an enhancement in Fas/APO-1 and its two forms of ligands, membrane-bound Fas ligand (mFasL) and soluble Fas ligand (sFasL), as well as caspase, were responsible for the apoptotic effect induced by tetrazolium violet. The conclusion of this study is that tetrazolium violet induced p53 expression which caused cell cycle arrest and apoptosis. These findings suggest that tetrazolium violet has strong potential for development as an agent for treatment lung cancer.

• 동의생리병리학회지
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• 제21권4호
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• pp.973-981
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• 2007

In the present study, we investigated the antiproliferative activity of the water extract of Samgibopae-tang (SGBPT) in NCI-H460 and A549 non-small-cell lung cancer cell lines. We found that exposure of A549 cells to SGBPT resulted in the growth inhibition in a dose-dependent manner as measured by MTT assay, however SGBPT did not affect the growth of NCI-H460 cells. The antiproliferative effect by SGBPT treatment in A549 cells was associated with morphological changes such as membrane shrinking and cell rounding up. SGBPT treatment did not induce the cell cycle arrest in both cell lines, however the frequency of sub-G1 population was concentration-dependently increased by SGBPT treatment in A549 cells. SGBPT treatment partially induced the expression of tumor suppressor p53 in A549 cells and the expression of cyclin-dependent kinase inhibitor p21(WAF1/CIP1) was markedly increased in both transcriptional and translational levels in A549 cells. The up-regulation of p21 by SGBPT occurred in a similar a concentration dependent manner to that observed with the inhibition of cell viability and induction of sub-G1 population of the cell cycle. However SGBPT treatment did not affect other growth regulation-related genes such as early growth response-1 (Egr-1), nonsteroidal anti-inflammatory drug-activated gene-1 (NAG-1), inducible nitric oxide synthease (iNOS), cyclooxygenases (COXs), telomere-regulatory factors in A549 as well as NCI-H460 cells. Taken together, these findings suggested that SGBPT-induced inhibition of human lung carcinoma A549 cell growth was aoosciated with the induction of p21 and the results provided important new insights into the possible molecular mechanisms of the anti-cancer activity of SGBPT.

• IMMUNE NETWORK
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• 제2권1호
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• pp.19-24
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• 2002

Background: Salvia miltiorrhiza (SM), a traditional oriental medicine, has been reported to have anti-tumor properties, but its exact mechanism remains to be elucidated. In this study, we investigated several of the molecular events that occur in human breast carcinoma MCF-7 cells and human pulmonary adenocarcinoma A549 cells. Methods: For this purpose, we evaluated the growth-inhibitory effect of SM in association with the expressions of p53, p21, cyclin D1, and pRb, which are known to be involved in cell cycle arrest. The extent of thymidine incorporation was also examined to assess G1/S phase cell cycle arrest in both cells by $^3H$-thymidine incorporation. Results: Our results show that SM inhibits the growth and the proliferation of MCF-7 and A549 cells. Furthermore, we also observed increased expression of p21 via a p53-dependent pathway in both cell lines after treating with SM. In addition, treatment with SM for 24 hours caused the suppression of hyperphosphorylated retinoblastoma protein (pRb) expression and the dephosphorylation of pRb. Conclusion: These findings suggest that the growth inhibitory and the anti-proliferation effects of SM on MCF-7 cells and A549 cells are mediated via the decreased expression and dephosphorylation of pRB by p21 up-regulation in a p53-dependent manner. To the best of our knowledge, this study is the first to report upon the molecular mechanisms involved in SM-induced tumor cell growth inhibition.

• Molecules and Cells
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• 제45권10호
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• pp.718-728
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• 2022

Splicing factor B subunit 4 (SF3B4), a component of the U2-pre-mRNA spliceosomal complex, contributes to tumorigenesis in several types of tumors. However, the oncogenic potential of SF3B4 in lung cancer has not yet been determined. The in vivo expression profiles of SF3B4 in non-small cell lung cancer (NSCLC) from publicly available data revealed a significant increase in SF3B4 expression in tumor tissues compared to that in normal tissues. The impact of SF3B4 deletion on the growth of NSCLC cells was determined using a siRNA strategy in A549 lung adenocarcinoma cells. SF3B4 silencing resulted in marked retardation of the A549 cell proliferation, accompanied by the accumulation of cells at the G0/G1 phase and increased expression of p27, p21, and p53. Double knockdown of SF3B4 and p53 resulted in the restoration of p21 expression and partial recovery of cell proliferation, indicating that the p53/p21 axis is involved, at least in part, in the SF3B4-mediated regulation of A549 cell proliferation. We also provided ubiquitination factor E4B (UBE4B) is essential for p53 accumulation after SF3B4 depletion based on followings. First, co-immunoprecipitation showed that SF3B4 interacts with UBE4B. Furthermore, UBE4B levels were decreased by SF3B4 depletion. UBE4B depletion, in turn, reproduced the outcome of SF3B4 depletion, including reduction of polyubiquitinated p53 levels, subsequent induction of p53/p21 and p27, and proliferation retardation. Collectively, our findings indicate the important role of SF3B4 in the regulation of A549 cell proliferation through the UBE4B/p53/p21 axis and p27, implicating the therapeutic strategies for NSCLC targeting SF3B4 and UBE4B.

• 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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• 제23권11호
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• pp.1351-1359
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• 2013

${\beta}$-Ionone의 인체 비소폐암세포 A-549 cells (human non-small lung cancer A-549 cell)에 대한 anti-proliferative effect에 관한 연구를 수행하였다. A-549 cell에 다양한 농도의 ${\beta}$-ionone (1, 5, 10, and 15 ${\mu}M$)을 2, 4, 6일 간 처리하고, 배양 2일에 A-549 cell의 생육억제와 관련되는 biochemical marker를 측정하였다. ${\beta}$-Ionone은 A-549 cell 생육을 dose와 time 의존적으로 저해하였다. ${\beta}$-Ionone 배양 2일의 $IC_{50}$은 5.0 ${\mu}g/ml$이었다. ${\beta}$-Ionone은 농도 의존적으로 apoptosis를 유도하였다. ${\beta}$-Ionone은 p53, p21 및 Bax protein 수준을 증가시켰으나, Bcl-2 protein 발현은 억제시켰다. ${\beta}$-ionone은 cytosol cytochrome c 함량을 증가시켰고, caspase-9과 caspase-3 효소 활성증가를 유도하였다. 또한, ${\beta}$-ionone은 $cPLA_2$와 COX-2 protein level을 감소시켰다. 이와 같은 결과는 ${\beta}$-ionone의 A-549 cell에 대한 생육억제효과는 Bax와 Bcl-2 gene 발현을 reciprocal regulation하여 유도한 apoptosis와 $cPLA_2$ 및 COX-2 protein 발현 억제에 기인함을 의미한다.

• 동의생리병리학회지
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• 제18권4호
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• pp.1147-1152
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• 2004

To investigate the anti-cancer effects of aqueous extract of Cheonkumwikyung-tang (CKWKT) on the growth of human lung carcinoma cell line A549, we performed various biochemical experiments such as the effects of CKWKT on the cell proliferation and viability, the morphological changes, the effects on expression of apoptosis and cell growth-regulatory gene products. Results obtained are as follow; CKWKT treatment declined the cell viability and proliferation of A549 cells in a concentration-dependent manner. The anti-proliferative effect by CKWKT treatment in A549 cells was associated with morphological changes such as membrane shrinking and cell rounding up. CKWKT treatment induced apoptotic cell death of A549 cells in a concentration-dependent manner, which was associated with inhibition and/or degradation of apoptotic target proteins such poly(ADP-ribose) polymerase, β-catenin and phospholipase C-γ1. Western blot analysis revealed that the levels cyclin-dependent kinase inhibitor p21 expression were induced by CKWKT treatment in A549 cells. Taken together, these findings suggest that CKWKT-induced inhibition of human lung cancer cell proliferation is associated with the induction of apoptotic cell death via regulation of several major growth regulatory gene products and CKWKT may have therapeutic potential in human lung cancer.