• 한국식품영양과학회지
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• 제31권2호
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• pp.329-332
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• 2002

본 연구는 사람의 간암세포인 HepG2 세포를 대상으로 강력한 암 예방 효과물질을 함유하고 있을 것으로 추측되는 향버섯 메탄올 추출물의 암세포 성장 저해 효과를 검토하고 또한 암세포 성장 억제 효과의 분자생물학적 기전을 파악하기 위하여 암세포주의 세포주기 조절인자들의 발현을 조사하였다. 향버섯 메탄을 추출물의 HePG2세포에 대한 성장 저해 효과를 MTT assay로 검토한 결과 높은 암세포 성장 저해 효과를 나타내었으며 사람의 정상 간세포인 Chang cell에서는 세포독성이 나타나지 않았다. 또한 향버섯 추출물의 작용으로 HepG2 세포에서 cyclin A와 Dl 단백질의 발현이 억제 되었으며 cyclin Bl 단백질의 발현은 증가하는 경향을 나타내었다. 그리고 암 억제 단백질인 p53의 발현은 전반적으로 증가되었으며, 이와 대조적으로 PCNA 단백질은 감소하는 경향을 나타내었고 세포분열 억제 단백질 p27의 발현은 증가 하는 경향을 나타내었다. 이러한 결과로 볼 때 향버섯 메탄올 추출물은 간암세포의 세포주기 중 Gl기 에서 S기로의 진행을 조절하는 인자인 cyclin A와 cyclin Dl 발현을 억제시키고 p53, p27 단백질을 활성화 시킴과 동시에 PCNA 작용을 억제 함으로써 세포주기 중 Gl/S기 차단을 유도하여 암세포 증식을 억제한 것으로 추정된다.

• 약학회지
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• 제41권1호
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• pp.94-98
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• 1997

Ceramide. a product of sphingomyelin hydrolysis, has been proposed as a lipid second messenger mediating antiproliferative activation. In this study, we examined the role of the cell cycle-related proteins in the ceramide-mediated growth suppression. Treatment of U-937 cells with C$_2$-ceramide(N-acetylsphingosine) resulted in growth suppression in a time- and concentration dependent manner. Ceramide induced concentration dependent dephosphorylation of retinoblastoma gene product (Rb). Rb remains hypophosphorylated in synchronized cells even after serum stimulation in the presence of ceramide. Ceramide decreased the expression of cyclin D$_1$ and cyclin E levels. These results suggest that antiproliferative effect of ceramide is associated with hypophosphorylation of Rb and decreased expression of cyclin D1 and cyclin E.

• Journal of Ginseng Research
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• 제39권2호
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• pp.125-134
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• 2015

Background: Black ginseng (Ginseng Radix nigra, BG) refers to the ginseng steamed for nine times and fine roots (hairy roots) of that is called fine black ginseng (FBG). It is known that the content of saponin of FBG is higher than that of BG. Therefore, in this study, we examined antitumor effects against MCF-7 breast cancer cells to target the FBG extract and its main component, ginsenoside Rg5 (Rg5). Methods: Action mechanism was determined by MTT assay, cell cycle assay and western blot analysis. Results: The results from MTT assay showed that MCF-7 cell proliferation was inhibited by Rg5 treatment for 24, 48 and 72 h in a dose-dependent manner. Rg5 at different concentrations (0, 25, 50 and $100{\mu}M$), induced cell cycle arrest in G0/G1 phase through regulation of cell cycle-related proteins in MCF-7 cells. As shown in the results from western blot analysis, Rg5 increased expression of p53, $p21^{WAF1/CIP1}$ and $p15^{INK4B}$ and decreased expression of Cyclin D1, Cyclin E2 and CDK4. Expression of apoptosiserelated proteins including Bax, PARP and Cytochrome c was also regulated by Rg5. These results indicate that Rg5 stimulated cell apoptosis and cell cycle arrest at G0/G1 phase via regulation of cell cycle-associated proteins in MCF-7 cells. Conclusion: Rg5 promotes breast cancer cell apoptosis in a multi-path manner with higher potency compared to 20(S)-ginsenoside Rg3 (Rg3) in MCF-7 (HER2/ER+) and MDA-MB-453 (HER2+/ER) human breast cancer cell lines, and this suggests that Rg5 might be an effective natural new material in improving breast cancer.

• Natural Product Sciences
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• 제19권2호
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• pp.155-159
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• 2013

Honokiol, a naturally occurring neolignan mainly found in Magnolia species, has exhibited a potential anti-proliferative activity in human cancer cells. However, the growth inhibitory activity against hepatocellular carcinoma cells and the underlying molecular mechanisms has been poorly determined. The present study was designed to examine the anti-proliferative effect of honokiol in SK-HEP-1 human hepatocellular cancer cells. Honokiol exerted anti-proliferative activity with cell-cycle arrest at the G0/G1 phase and sequential induction of apoptotic cell death. The cell-cycle arrest was well correlated with the down-regulation of checkpoint proteins including cyclin D1, cyclin A, cyclin E, CDK4, PCNA, retinoblastoma protein (Rb), and c-Myc. The increase of sub-G1 peak by the higher concentration of honokiol ($75{\mu}M$) was closely related to the induction of apoptosis, which was evidenced by decreased expression of Bcl-2, Bid, and caspase-9. Hohokiol was also found to attenuate the activation of signaling proteins in the Akt/mTOR and ERK pathways. These findings suggest that the anti-proliferative effect of honokiol was associated in part with the induction of cell-cycle arrest, apoptosis, and dow-nregulation of Akt/mTOR signaling pathways in human hepatocellular cancer cells.

• Asian Pacific Journal of Cancer Prevention
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• 제13권9호
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• pp.4341-4346
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• 2012

Purpose: The aim of this study was to cast light on initiating molecular events associated with the development of premalignant oral lesions induced by tobacco and/or areca nut. Method: Immunohistochemical analyses of cell cycle regulatory proteins (LIMD1, RBSP3, p16, RB, phosphorylated RB, p53), EGFR and SH3GL2 (EGFR associated protein) were performed with inflammatory/ulcerative epithelium and adjacent hyperplastic/mild dysplastic lesions. Results: No change in expression of the proteins was seen in inflammatory epithelium. Reduced nuclear expression of LIMD1 was evident in ulcerative epithelium. In hyperplastic lesions, reduced expression of RBSP3, p16, SH3GL2 and overexpression of p-RB and EGFR were apparent. Reduced nuclear expression of p53 was observed in mild dysplastic lesions. Conclusion: Our data suggest that inactivation of LIMD1 in ulcerative epithelium might predispose the tissues to alterations of other cell cycle regulatory and EGFR signaling proteins needed for the development of premalignant oral lesions.

• 한국식품영양학회지
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• 제24권2호
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• pp.258-267
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• 2011

14-3-3 is a highly conserved, ubiquitously expressed protein family. It associates with diverse cellular proteins through its specific phosphoserine/phosphothreonine-binding activity and thus contributes to the regulation of crucial cellular processes such as metabolism, signal transduction, cell-cycle control, apoptosis, protein trafficking, transcription and stress responses. This study aims to determine changes in levels of 14-3-3 isoforms and 14-3-3 - associated proteins in Helicobacter pylori(H. pylori)-infected gastric epithelial AGS cells. AGS cells were stimulated with H. pylori(NCTC 11637) at the ratio of 300:1(bacterium:cell). Western blot analysis revealed that 14-3-3 $\sigma$ was elevated at 3 hr after H. pylori treatment. Other isoforms were not significantly affected by H. pylori infection. Using immunoprecipitation to 14-3-3 $\sigma$, followed by proteomic analysis, we found that S phase kinase associated protein isoform 2 bound to 14-3-3 $\sigma$ has increased. In contrast, three proteins (DEAD-box polypeptide 3, heterogeneous nuclear ribonucleoprotein H2 and WD repeat-containing protein isoform 1) bound to 14-3-3 decreased by H. pylori infection. Our results suggest that 14-3-3 may play an important regulatory role in H. pylori-induced signal transduction in gastric epithelial cells.

• Nutrition Research and Practice
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• 제2권4호
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• pp.322-325
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• 2008

The aim of present study was to investigate the effects of kaempferol on cellular proliferation and cell cycle arrest and explore the mechanism for these effects in human breast carcinoma MDA-MB-453 cells. Cells were treated with kaempferol at various concentrations (ranging from 1 to $200\;{\mu}M$) for 24 and 48 hrs. Kaempferol significantly inhibited cancer cell growth in cells exposed to 50 and $10\;{\mu}M$ of kaempferol and incubated for 24 and 48 hrs, respectively. Exposure to kaempferol resulted in cell cycle arrest at the G2/M phase. Of the G2/M-phase related proteins, kaempferol down-regulated CDK1 and cyclin A and B in cells exposed to kaempferol. In addition, small DNA fragments at the sub-G0 phase were increased by up to 23.12 and 31.90% at 10 and $50\;{\mu}M$ incubated for 24 and 48 hrs, respectively. The kaempferol-induced apoptosis was associated with the up-regulation of p53. In addition, the phosphorylation of p53 at the Ser-15 residue was observed with kaempferol. Kaempferol inhibits cell proliferation by disrupting the cell cycle, which is strongly associated with the induction of arrest at G2/M phase and may induce apoptosis via p53 phosphorylation in human breast carcinoma MDA-MB-453 cells.

• The Korean Journal of Physiology and Pharmacology
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• 제14권5호
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• pp.299-304
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• 2010

Losartan is a selective angiotensin II (Ang II) type 1 ($AT_1$) receptor antagonist which inhibits vascular smooth muscle cells (VSMCs) contraction and proliferation. We hypothesized that losartan may prevent cell proliferation by activating AMP-activated protein kinase (AMPK) in VSMCs. VSMCs were treated with various concentrations of losartan. AMPK activation was measured by Western blot analysis and cell proliferation was measured by MTT assay and flowcytometry. Losartan dose- and time-dependently increased the phosphorylation of AMPK and its downstream target, acetyl-CoA carboxylase (ACC) in VSMCs. Losartan also significantly decreased the Ang II- or 15% FBS-induced VSMC proliferation by inhibiting the expression of cell cycle associated proteins, such as p-Rb, cyclin D, and cyclin E. Compound C, a specific inhibitor of AMPK, or AMPK siRNA blocked the losartan-induced inhibition of cell proliferation and the $G_0/G_1$ cell cycle arrest. These data suggest that losartan-induced AMPK activation might attenuate Ang II-induced VSMC proliferation through the inhibition of cell cycle progression.

• 한국식품영양과학회지
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• 제32권6호
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• pp.931-936
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• 2003

본 연구에서는 항암효과를 가진 성분을 포함하여 여러 다양한 생리활성 물질을 함유하고 있을 것으로 기대되는 노루궁뎅이 버섯(Hericium erinaceus)을 이용하여 암세포 성장저해효과와 세포주기 조절자인 cyclin 단백질의 발현에 미치는 영향을 조사하였다. 노루궁뎅이 버섯의 메탄을 추출물과 그 분획물들의 사람의 암세포주인 HT29와 HepG2에 대한 성장 저해 효과를 MTT assay로 검토한 결과 노루궁뎅이 버섯의 메탄을 추출물과 헥산, 클로로포름 그리고 에틸아세테이트 분획물들이 높은 암세포 성장 저해 효과를 나타내었으며 농도 의존적인 경향을 보였다. 그러나 사람의 정상 간세포인 Chang cell에서는 세포독성이 나타나지 않았다 그리고 노루궁뎅이 버섯 메탄올추출물이 간암 세포주인 HepG2의 cyclin 단백질 발현에 미치는 영향을 조사한 결과 노루궁뎅이 버섯 메탄을 추출물이 cyclin A와 D 단백질 발현을 다소 감소시켰으며 특히 cyclin B1에 대한 효과가 더욱 크게 나타나 1 mg/mL 농도에서 48시간 처리 하였을 때 대조군에 비해 30% 정도까지 단백질 발현이 감소하였다. 이러한 결과로 노루궁뎅이 버섯은 세포주기 중 G2기에서 M기로의 전환에 관여하는 cyclin B1 단백질의 발현을 크게 감소시키므로 세포주기 진행을 차단시켜 간암세포의 증식을 억제시키는 것으로 사료된다.

• Asian Pacific Journal of Cancer Prevention
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• 제14권11호
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• pp.6419-6425
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• 2013

Background: Neoadjuvant chemotherapy (NACT) is a treatment modality whereby chemotherapy is used as the initial treatment of HNSCC in patients presenting with advanced cancer that cannot be treated by other means. It leads to shrinkage of tumours to an operable size without significant compromise to essential oro-facial organs of the patients. The molecular mechanisms behind shrinkage due to NACT is not well elucidated. Materials and Methods: Eleven pairs of primary HNSCCs and adjacent normal epithelium, before and after chemotherapy were screened for cell proliferation and apoptosis. This was followed by immunohistochemical analysis of some cell cycle (LIMD1, RBSP3, CDC25A, CCND1, cMYC, RB, pRB), DNA repair (MLH1, p53) and apoptosis (BAX, BCL2) associated proteins in the same set of samples. Results: Significant decrease in proliferation index and increase in apoptotic index was observed in post-therapy tumors compared to pre-therapy. Increase in the RB/pRB ratio, along with higher expression of RBSP3 and LIMD1 and lower expression of cMYC were observed in post-therapy tumours, while CCND1 and CDC25A remained unchanged. While MLH1 remained unchanged, p53 showed higher expression in post-therapy tumors, indicating inhibition of cell proliferation and induction of apoptosis. Increase in the BAX/BCL2 ratio was observed in post-therapy tumours, indicating up-regulation of apoptosis in response to therapy. Conclusions: Thus, modulation of the G1/S cell cycle regulatory proteins and apoptosis associated proteins might play an important role in tumour shrinkage due to NACT.