• 동의생리병리학회지
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• 제19권3호
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• pp.671-676
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• 2005

In this study, we investigated the antioxidant effect of extract from Monascus pillosus, on the human wild-type p53 and p21 expressing A549 lung epithelial cell line and MCF-7 mammary adenocarcinoma cell line stimulated by NO. $P21^{waf/cip1}$ was identified as a gene induced in senescent cells. It is a cyclin-dependent kinase inhibitor and has been shown to cause cell cycle arrest and apoptosis. While p53-regulated stimulation of p21 appears to be central for the permanent growth-arrest, the role of p21 in p53-triggered cell death is unclear. Low dose of sodium nitroprusside (SNP) induced the development of senescence associated with increased expression of p53 and p21 in A549 cells. Inhibition of p21 transactivating activity requires high level correlates with the amount of p53 necessary to cause cell death. Association of p21 and p53 results in inhibition of p21-stimulated transcription. This requires a higher p53 level than is necessary for transcriptional activation of endogenous p53-responsive gene but correlates well with the level of p53 necessary to cause cell death. Exposure to W-1 inhibited oxidative stresses-induced senescence-like arrest, resulting in a significant reduction in p53 and p21 steady state levels. These results suggest that p53 and p21 play a central role in the onset of senescence. Thus, it is important to emphasize control of oxidative balance in tumor prevention and aging.

• Molecules and Cells
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• 제21권1호
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• pp.42-51
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• 2006

We investigated the mechanism of contraction induced by S1P in esophageal smooth muscle cells. Western blot analysis demonstrated that $S1P_1$, $S1P_2$, $S1P_3$, and $S1P_5$ receptors existed in the cat esophagus. Only penetration of EDG-5 ($S1P_2$) antibody into permeabilized cells inhibited S1P-induced contraction. Pertussis toxin (PTX) also inhibited contraction, suggesting that it was mediated by $S1P_2$ receptors coupled to a PTXsensitive $G_i$ protein. Specific antibodies to $G_{i2}$, $G_q$ and $G_{\beta}$ inhibited contraction, implying that the S1P-induced contraction depends on PTX-insensitive $G_q$ and $G_{\beta}$ dimers as well as the PTX-sensitive $G_{i2}$. Contraction was not affected by the phospholipase $A_2$ inhibitor DEDA, or the PLD inhibitor ${\rho}$-chloromercuribenzoate, but it was abolished by the PLC inhibitor U73122. Incubation of permeabilized cells with $PLC{\beta}3$ antibody also inhibited contraction. Contraction involved the activation of a PKC pathway since it was affected by GF109203X and chelerythrine. Since $PKC{\varepsilon}$ antibody inhibited contraction, $PKC{\varepsilon}$ may be required. Preincubation of the muscle cells with the MEK inhibitor PD98059 blocked S1P-induced contraction, but the p38 MAP kinase inhibitor SB202190 did not. In addition, co-treatment of cells with GF 109203X and PD98059 did not have a synergistic effect, suggesting that these two kinases are involved in the same signaling pathway. Our data suggest that S1P-induced contraction in esophageal smooth muscle cells is mediated by $S1P_2$ receptors coupled to PTX-sensitive $G_{i2}$ proteins, and PTX-insensitive $G_q$ and $G_{\beta}$ proteins, and that the resulting activation of the $PLC{\beta}3$ and $PKC{\varepsilon}$ pathway leads to activation of a p44/p42 MAPK pathway.

• 한국식품영양과학회지
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• 제33권1호
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• pp.1-6
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• 2004

$\beta$-Sitosterol은 과일과 야채 등을 포함한 대부분의 고등식물에 존재하는 중요한 phytosterol의 하나로서, 인체 암의 예방과 치료에 매우 유효한 것으로 보고되어져 오고 있다. 본 연구에서는 $\beta$-sitosterol의 암세포 증식억제 기전의 해석을 시도하기 위하여 인체 대장암세포 HCT116의 증식에 미치는 $\beta$-sitosterol의 영향을 조사하였다. $\beta$-Sitosterol의 처리로 HCT116 암세포의 증식은 처리 농도 의존적으로 감소되었으며, 특히 7.5 $\mu$M 이상 처리에서는 급격한 성장억제 효과가 있었다. 또한 5.0 $\mu$M 처리군에서부터 apoptotic body의 형성이 관찰되었고, $\beta$-catenin 단백질의 분해 현상과 연관성이 있었다. 그리고 $\beta$-sitosterol이 처리된 암세포에서는 종양억제유전자 p53 및 Cdk inhibitor p21의 발현이 전사 및 번역 수준에서 모두 증가되었다. 본 결과는 그동안 연구가 거의 진행되어져 있지 않았던 $\beta$-sitosterol에 의한 암세포주기 조절 해석을 위한 주요한 자료로 활용될 것이다.

• The Korean Journal of Physiology and Pharmacology
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• 제20권2호
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• pp.161-168
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• 2016

Abnormal localization of tumor suppressor proteins is a common feature of renal cancer. Nuclear export of these tumor suppressor proteins is mediated by chromosome region maintenance-1 (CRM1). Here, we investigated the antitumor effects of a novel reversible inhibitor of CRM1 on renal cancer cells. We found that S109 inhibits the CRM1-mediated nuclear export of RanBP1 and reduces protein levels of CRM1. Furthermore, the inhibitory effects of S109 on CRM1 is reversible. Our data demonstrated that S109 significantly inhibits proliferation and colony formation of renal cancer cells. Cell cycle assay showed that S109 induced G1-phase arrest, followed by the reduction of Cyclin D1 and increased expression of p53 and p21. We also found that S109 induces nuclear accumulation of tumor suppressor proteins, Foxo1 and p27. Most importantly, mutation of CRM1 at Cys528 position abolished the effects of S109. Taken together, our results indicate that CRM1 is a therapeutic target in renal cancer and the novel reversible CRM1 inhibitor S109 can act as a promising candidate for renal cancer therapy.

• 동의생리병리학회지
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• 제16권6호
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• pp.1177-1183
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• 2002

We investigated the effects of Sabaek-san (SBS) water extract on the cell proliferation of human lung carcinoma A549 cells. SBS treatment resulted in the inhibition of cell proliferation in a concentration-dependent manner. This anti-proliferative effect of A549 cells by SBS treatment was associated with morphological changes such as membrane shrinking and cell rounding up. DNA flow cytometric histograms showed that population of G1 phase of the cell cycle was increased by SBS treatment in a concentration-dependent manner. SBS treatment induced a marked accumulation of tumor suppressor p53 and a concomitant induction of cyclin-dependent kinase (Cdk) inhibitor p21WAF1/CIP, which appears to be transcriptionally upregulated and is p53 dependent. In addition, SBS treatment resulted in down-regulation of cyclooxygenase-2 (COX-2) as determined by RT-PCR analysis. The present results indicated that SBS-induced inhibition of lung cancer cell proliferation is associated with the blockage of G1/S progression the induction of apoptosis.

• Molecules and Cells
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• 제26권4호
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• pp.396-403
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• 2008

The first ORF of the ARV S1133 S1 segment encodes the nonstructural protein p10, which is responsible for the induction of cell syncytium formation. However, p10-dependent signaling during syncytium formation is fully unknown. Here, we show that dominant negative RhoA, Rho inhibitor C3 exoenzyme, ROCK/Rho-kinase inhibitor Y-27632 and Rac1 inhibitor NSC23766 inhibit p10-mediated cell fusion. p10 over-expression is concomitant with activation and membrane translocation of RhoA and Rac1, but not cdc42. RhoA and Rac1 downstream events, including JNK phosphorylation and transcription factor AP-1 and $NF-{\kappa}B$ activation, as well as MLC expression and phosphorylation are simultaneously activated by p10. p10 point mutant T13M possessed 20% fusion-inducing ability and four p10 fusion-deficient mutants V15M, V19M, C21S and L32A reduced or lost their ability to activate RhoA and Rac1 signaling. We conclude that p10-mediated syncytium formation proceeds by utilizing RhoA and Rac1-dependent signaling.

• 동의생리병리학회지
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• 제18권2호
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• pp.553-560
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• 2004

In the present study, we investigated the anti-proliferative effects of aqueous extract of Wikyung-tang(WKT) on the growth of human lung carcinoma cell line A549. WKT treatment declined the cell viability and proliferation of A549 cells in a concentration-dependent manner. The anti-proliferative effects by WKT treatment in A549 cells was associated with morphological changes such as membrane shrinking and cell rounding up. WKT treatment induced an inhibition and/or degradation of apoptotic target proteins such poly(ADP-ribose) polymerase (PARP) and phospholipase C-γ1 (PLC-γ1). WKT treatment did not affect the levels of other Bcl-2 family gene products, such as Bcl-2, Bax and Bad. Western blot analysis and RT-PCT data revealed that the levels of tumor suppressor p53 and cyclin-dependent kinase inhibitor p21 were induced by WKT treatment in A549 cells. Additionally, WKT treatment induced the down-regulation of telomerase reverse transcriptase mRNA (hTERT) expression of A549 cells, however, the levels of other telomere-regulatory gene products were not affected. Taken together, these findings suggest that WKT-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 WKT may have therapeutic potential in human lung cancer.

• BMB Reports
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• 제29권4호
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• pp.380-385
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• 1996

Ovomucoid third domain is a serine proteinase inhibitor protein which consists of 56 amino acid residues. A fifty picosecond molecular dynamics (MD) simulation was carried out for ovomucoid third domain protein with 5 $\AA$ layer of water molecules. A comparison of main chain atoms in the MD averaged structure with the crystal structure showed that most of the backbone structures are maintained during the simulation. Investigation of the intramolecular hydrogen bondings indicated that most of the interactions between main chain atoms were conserved, whereas those between side chains were reorganized for the period of the simulation. Especially, the side chain interactions around the scissile bond of reactive site P1 (Met18) were found to be more extensive for the MD structures. During the simulation, hydrogen bonds were maintained between the side chains of Glu19 and Arg21 as well as those of Thr17 and Glu19. Extensive side chain interactions observed in the MD structures may shed light on the question of why protein proteinase inhibitors are strong inhibitors for proteinases rather than good substrates.

• 생명과학회지
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• 제15권5호
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• pp.726-733
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• 2005

Histone deacetylase (HDAC) 억제제가 새로운 항암치료제 후보물질로서 유용성이 높은 것으로 평가되지만, 아직까지 인체폐암세포에 관한 연구는 상대적으로 미미한 실정이다. 따라서 본 연구에서는 폐암세포에 미치는 HDAC 억제제의 항암작용 기전을 조사하기 위하여 A549 인체폐암세포주를 대상으로 암세포의 증식에 미치는 대표적인 HDAC 억제제인 tichostatin A (TSA)에 의한 영향을 세포주기 조절관련인자 중심으로 조사하였다. TSA의 처리에 의하여 A549 폐암세포의 증식은 처리 농도 의존적으로 억제되었으며, 심한 형태적 변형을 동반하였다. 저농도 처리군에서는 TSA 농도가 증가할수록 세포주기 G1기의 빈도가 증가하였으나, 고농도 처리군에서는 G2/M기에 속하는 세포의 빈도가 증가되었다. 또한 apoptosis 유발의 간접적인 지표가 되는 sub-G1기에 속하는 세포의 빈도 역시 TSA 처리 농도 의존적으로 매우 증가되었다. 이러한 TSA의 A549 폐암세포 증식억제 효과는 cyclins 및 CdkS의 발현 억제, 종양억제유전자인 p53 및 Cdks 억제제인 p21과 p27의 발현 증가와도 연관성이 있었다. TSA의 항암 기전을 규명하기 위해서는 더 많은 연구가 부가적으로 필요하겠지만, 본 연구의 결과들에 의하면 TSA는 강력한 인체폐암세포의 증식 억제 및 항암작용이 있음을 시사하여 준다고 할 수 있다.

• 대한약학회:학술대회논문집
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• 대한약학회 2000년도 NEW STRATEGY FOR DRUG DEVELOPMENT IN POST-GENOMIC ERA(대한약학회)
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• pp.182.2-182.2
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• 2000