• Title/Summary/Keyword: growth suppressor

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Role of Transforming Growth Factor-β in Tumor Invasion and Metastasis

  • Kim, Eun-Sook;Moon, Aree
    • Toxicological Research
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    • v.23 no.3
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    • pp.197-205
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    • 2007
  • Cancer metastasis is a major determinant of cancer patient mortality. Mounting evidence favors a strong positive role for $TGF-{\beta}$ in human cancer progression. The complex pattern on cross-talk of $TGF-{\beta}$ and the related other signaling pathways is an important area of investigation that will ultimately contribute to understanding of the bifunctional role of $TGF-{\beta}$ in cancer progression. This review summarizes some of the current understanding of $TGF-{\beta}$ signaling with a major focus in its contribution to the tumor cell invasion and metastasis. Five issues are addressed in this review: (1) $TGF-{\beta}$ signaling, (2) $TGF-{\beta}$ and EMT, (3) $TGF-{\beta}$ and MMP, (4) $TGF-{\beta}$ and Ras, and (5) Role of $TGF-{\beta}$ in invasion and metastasis. Due to the bifunctional cellular effects of $TGF-{\beta}$, as a tumor promoter and a tumor suppressor, more precisely defined $TGF-{\beta}$ signaling pathways need to be elucidated. According to the current literature, $TGF-{\beta}$ is clearly a major factor stimulating tumor progression through a complex spectrum of the interplay and cross-talk between various signaling molecules. Understanding the role of $TGF-{\beta}$ in invasion and metastasis will provide valuable information on establishing strategies to manipulate $TGF-{\beta}$ signaling which should be a high priority for the development of anti-metastatic therapeutics.

Apoptosis Induction of MCF-7 Human Breast Carcinoma Cells by Butein (Butein에 의한 MCF-7 유방암 세포의 세포사멸에 의한 항암 효과)

  • Song, Ba-Da;Kim, Sun-Rye;Kim, Sung-Hun;Shin, Yong-Cheol;Ko, Seong-Gyu
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.24 no.3
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    • pp.385-389
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    • 2010
  • Butein(3,4,2',4-tetrahydroxychalcone) has been reported anticancer effects in several cancer type, which is prostate, bladder cancer but breast cancer is not. This study was to investigate the antiproliferative effects by butein(3,4,2',4-tetrahydroxychalcone) in MCF-7 human breast carcinoma cells. We invastigated the effects of dose-dependently cell growth inhibition by butein, which could be proved by WST-1 assay. Also, flow cytometry analysis was butein increase percentage of subG1 phase. As well as, butein induces apoptosis through the expression of caspase-8,-3 and poly(ADP-ribose) polymerase(PARP) activation but not in DMSO treated cells. Taken together, this results suggest that butein induced MCF-7 apoptosis through extrinsic pathway and thus may have potential tumor suppressor in breast cancer.

Requirement of Bni5 Phosphorylation for Bud Morphogenesis in Saccharomyces cerevisiae

  • Nam, Sung-Chang;Sung, Hye-Ran;Chung, Yeon-Bok;Lee, Chong-Kil;Lee, Dong-Hun;Song, Suk-Gil
    • Journal of Microbiology
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    • v.45 no.1
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    • pp.34-40
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    • 2007
  • In budding yeast, G2/M transition is tightly correlated with bud morphogenesis regulated by Swel and septin that plays as a scaffold to recruits protein components. BNI5 isolated as a suppressor for septin defect is implicated in septin organization and cytokinesis. The mechanism by which Bni5 regulates normal septin function is not completely understood. Here, we show that Bni5 phosphorylation is required for mitotic entry regulated by Swel pathway. Bni5 modification was evident from late mitosis to G1 phase, and CIP treatment in vitro of affinity-purified Bni5 removed the modification, indicative of phosphorylation on Bni5. The phosphorylation-deficient mutant of BNI5 (bni5-4A) was defective in both growth at semi-restrictive temperature and suppression of septin defect. Loss of Bni5 phosphorylation resulted in abnormal bud morphology and cell cycle delay at G2 phase, as evidenced by the formation of elongated cells with multinuclei. However, deletion of Swel completely eliminated the elongated-bud phenotypes of both bni5 deletion and bni5-4A mutants. These results suggest that the bud morphogenesis and mitotic entry are positively regulated by phosphorylation-dependent function of Bni5 which is under the control of Swel morphogenesis pathway.

The Phosphorylation Status of Merlin Is Important for Regulating the Ras-ERK Pathway

  • Jung, Ju Ri;Kim, Hongtae;Jeun, Sin-Soo;Lee, Joo Yong;Koh, Eun-Jeoung;Ji, Cheol
    • Molecules and Cells
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    • v.20 no.2
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    • pp.196-200
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    • 2005
  • The neurofibromatosis type2 (NF2) tumor suppressor gene product, merlin, is structurally related to the ezrin-radixin-moesin (ERM) family of proteins that anchor the actin cytoskeleton to specific membrane proteins and participate in cell signaling. However, the basis of the tumor suppressing activity of merlin is not well understood. Previously, we identified a role of merlin as an inhibitor of the Ras-ERK signaling pathway. Recent studies have suggested that phosphorylation of merlin, as of other ERM proteins, may regulate its function. To determine whether phosphorylation of merlin affects its suppression of Ras-ERK signaling, we generated plasmids expressing full-length merlin with substitutions of serine 518, a potential phosphorylation site. A substitution that mimics constitutive phosphorylation (S518D) abrogated the ability of merlin to suppress effects of the Ras-ERK signaling pathway such as Ras-induced SRE transactivation, Elk-mediated SRE transactivation, Ras-induced ERK phosphorylation and Ras-induced focus formation. On the other hand, an S518A mutant, which mimics nonphosphorylated merlin, acted like wild type merlin. These observations show that mimicking merlin phosphorylation impairs not only growth suppression by merlin but also its inhibitory action on the Ras-ERK signaling pathway.

Development of TGF-$\beta$ Resistance During Malignant Progression

  • Kim, Yong-Seok;Yi, Young-Suk;Choi, Shin-Geon;Kim, Seong-Jin
    • Archives of Pharmacal Research
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    • v.22 no.1
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    • pp.1-8
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    • 1999
  • Transforming growth factor-$\beta$ (TGF-$\beta$) is the prototypical multifunctional cytokine, participating in the regulation of vital cellular activities such as proliferation and differentiations as well as a number of basic physiological functions. The effects of TGF-$\beta$ are critically dependent on the expression and distribution of a family of TGF-$\beta$ receptors, the TGF-$\beta$ types I, II, and III. It is now known that a wide variety of human pathology can be caused by aberrant expression and function of these receptors. the coding sequence of the type II receptor (RII) appears to render it uniquely susceptible to DNA replication errors in the course of normal cell division. By virtue of its key role in the regulation of cell proliferation, TGF-$\beta$ RII should be considered as a tumor suppressor gene. High levels of mutation in the TGF-$\beta$ RII gene have been observed in a wide range of primarily epithelial malignancies, including colon and gastric cancer. It appears likely that mutation of the TGF-$\beta$ RII gene may be a very critical step in the pathway of carcinogenesis.

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Hepatoprotective Functions of Sulfur Containing Amino Acids: Possibilities of Hepatocellular Carcinoma Prevention (황함유 아미노산의 간기능 보호 작용: 간세포암 예방의 가능성)

  • Ko, Kwang Suk
    • Korean Journal of Food Science and Technology
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    • v.44 no.6
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    • pp.653-657
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    • 2012
  • While it is known that sulfur containing amino acids (SCAA) are very important in regulating hepatocyte growth and preventing liver-diseases, the fundamental molecular mechanisms of how they exert their hepatoprotective functions are not well known. Since it is widely understood that the hepatic concentrations of S-adenosylmethionine (SAMe) in chronic liver disease patients are severely decreased, the pathophysiological importance of SAMe and its downstream antioxidant, glutathione should be discussed in order to see a big picture of relationship between SCAA and liver diseases. Chronic SAMe deficient mice have shown spontaneous hepatocellular carcinoma development due to impaired mitochondria functions with low levels of prohibitin1 protein, and through deficiency in many genes which are known to ameliorate genetic instability, such as APEX1 and DUSP1, the functions of which are recovered by SAMe treatment. In this review, current knowledge of the basic concepts of the mechanisms through which SCAAs protect the liver will be discussed in detail. Also, a possible tumor suppressor in livers, prohibitin1, and its functional relationship with SAMe will be discussed.

Structural and Thermodynamic Characteristics of cHLH Peptide and cHLH/HDM2 Complex

  • Im, Haeri;Cho, Sunhee;Ham, Sihyun
    • Proceeding of EDISON Challenge
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    • 2016.03a
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    • pp.62-66
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    • 2016
  • Tumor suppressor protein p53 loses its function upon binding with the HDM2 protein, and inhibiting the p53-HDM2 interaction is critical to suppress tumor cell growth. Recently, the cyclized helix-loop-helix peptide (cHLH) mimicking the ${\alpha}-helix$ part of the p53 protein has been designed and found to exhibit high binding affinity with HDM2. Here, we report the structural and thermodynamic characteristics of the bound complex of the cHLH peptide with the HDM2 protein. We performed molecular dynamics simulations to investigate the structural features of the cHLH peptide as well as its complex with the HDM2. The binding free energy calculation based on the integral equation theory was also executed to quantify the binding affinity for the cHLH/HDM2 complex and to understand the factors contributing to the binding affinity. We found a variety of factors for the helix stability of the cHLH peptide as well as in the complexation with the HDM2, which may provide an insight into the development of anti-cancer drug designs.

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Aspergillus fumigatus-derived demethoxyfumitremorgin C inhibits proliferation of PC3 human prostate cancer cells through p53/p21-dependent G1 arrest and apoptosis induction

  • Kim, Young-Sang;Park, Sun Joo
    • Fisheries and Aquatic Sciences
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    • v.24 no.1
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    • pp.1-9
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    • 2021
  • Human prostate cancer is the second most frequently diagnosed cancer worldwide, and its incidence rate continues to increase. Advanced prostate cancer is more difficult to treat than early forms due to its chemotherapy resistance. There is need for more effective agents that can inhibit the progression of advanced prostate cancer. Demethoxyfumitremorgin C (DMFTC) was isolated from the fermentation extract of the marine fungus Aspergillus fumigatus. Antiproliferative activity of DMFTC against human prostate cancer PC3 cells was examined through cell cycle analysis by flow cytometry, the fluorescent nuclear imaging analysis with propidium iodide (PI), and proteins expression related to cell cycle arrest and apoptosis were investigated via Western blotting. DMFTC inhibited PC3 cells growth through G1 phase cell cycle arrest and apoptosis induction. It activated the tumor suppressor p53 and the Cdk inhibitor p21, which regulate the cell progression into the G1 phase. Additionally, PI-positive late apoptotic non-viable cells were increased and the expression levels of the G1-positive downstream regulators cyclin D, cyclin E, Cdk2, and Cdk4 were decreased by DMFTC treatment. These results suggest that DMFTC induces G1 arrest and apoptosis induction through regulation of p53/p21-dependent cyclin-Cdk complexes, and it may be a useful therapeutic agent for the treatment of human advanced prostate cancer.

Emerging role of anti-proliferative protein BTG1 and BTG2

  • Kim, Sang Hyeon;Jung, In Ryeong;Hwang, Soo Seok
    • BMB Reports
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    • v.55 no.8
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    • pp.380-388
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    • 2022
  • The B cell translocation gene 1 (BTG1) and BTG2 play a key role in a wide range of cellular activities including proliferation, apoptosis, and cell growth via modulating a variety of central biological steps such as transcription, post-transcriptional, and translation. BTG1 and BTG2 have been identified by genomic profiling of B-cell leukemia and diverse lymphoma types where both genes are commonly mutated, implying that they serve as tumor suppressors. Furthermore, a low expression level of BTG1 or BTG2 in solid tumors is frequently associated with malignant progression and poor treatment outcomes. As physiological aspects, BTG1 and BTG2 have been discovered to play a critical function in regulating quiescence in hematopoietic lineage such as Hematopoietic stem cells (HSCs) and naive and memory T cells, highlighting their novel role in maintaining the quiescent state. Taken together, emerging evidence from the recent studies suggests that BTG1 and BTG2 play a central anti-proliferative role in various tissues and cells, indicating their potential as targets for innovative therapeutics.

Effect of Extract of Acanthopanax Senticosus Fruit on Breast Cancer Cells (가시오가피 열매 추출물이 유방암 세포주에 미치는 영향)

  • Hwang, Jong-hyun;Kim, Seung-man;Hwang, Gwi-seo;Jeon, Chan-yong;Kang, Ki-sung
    • The Journal of Internal Korean Medicine
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    • v.43 no.4
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    • pp.529-541
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    • 2022
  • Objectives: Acanthopanax senticosus is a tree used in traditional medicine for various diseases. In this study, we investigated the anti-cancer effects of a water extract of Acanthopanax senticocus fruit (ASF) on 2 human breast cancer cell lines (MCF-7 and MDA-MB-231). Methods: The MTT assay was used to assess cell proliferation. The expression of apoptosis-related genes was assessed by quantitative real-time PCR. Results: ASF treatment caused a dose-dependent inhibition of cell growth in both estrogen-independent MDA-MB-231 and estrogen-dependent MCF-7 breast cancer cells. ASF decreased mRNA expression of the apoptotic suppressor gene Bcl-xL, and increased mRNA expression of proapoptotic genes. ASF increased the mRNA expression of p21 and RIP-1 in both cell types. ASF decreased the mRNA expression of survivin in the MCF-7 cell line. Conclusions: ASF exhibits anti-cancer activity involving apoptotic cell death.