• Title/Summary/Keyword: PTEN

Search Result 100, Processing Time 0.052 seconds

Induction of Apoptosis by IGFBP3 Overexpression in Hepatocellular Carcinoma Cells

  • Han, Jian-Jun;Xue, De-Wen;Han, Qiu-Rong;Liang, Xiao-Hong;Xie, Li;Li, Sheng;Wu, Hui-Yong;Song, Bao
    • Asian Pacific Journal of Cancer Prevention
    • /
    • v.15 no.23
    • /
    • pp.10085-10089
    • /
    • 2015
  • Background: The insulin-like growth factor (IGF) system comprises a group of proteins that play key roles in regulating cell growth, differentiation, and apoptosis in a variety of cellular systems. The aim of this study was to investigate the role of insulin-like growth factor binding protein 3 (IGFBP3) in hepatocellular carcinoma. Materials and Methods: Expression of IGF2, IGFBP3, and PTEN was analyzed by qRT-PCR. Lentivirus vectors were used to overexpress IGFBP3 in hepatocellular carcinoma cell (HCC) lines. The effect of IGFBP3 on proliferation was investigated by MTT and colony formation assays. Results: Expression of IGF2, IGFBP3, and PTEN in several HCC cell lines was lower than in normal cell lines. After 5-aza-2'-deoxycytidine/trichostatin A treatment, significant demethylation of the promoter region of IGFBP3 was observed in HCC cells. Overexpression of IGFBP3 induced apoptosis and reduced colony formation in HUH7 cells. Conclusions: Expression of IGF2, IGFBP3, and PTEN in several HCC cell lines was lower than in normal cell lines. After 5-aza-2'-deoxycytidine/trichostatin A treatment, significant demethylation of the promoter region of IGFBP3 was observed in HCC cells. Overexpression of IGFBP3 induced apoptosis and reduced colony formation in HUH7 cells.

Apoptosis-inducing Effect of Takrisodokyeum Extract in Androgen Independent Prostate Cancer Cells (남성호르몬 비의존형 전립선 암세포에서 탁리소독음(托裏消毒飮) 추출물의 세포고사 유도 효과)

  • Lee, Hyung-Jae;Kwon, Kang-Beom;Shin, Byung-Cheul;Kim, Eun-Kyung;Han, Mi-Jeong;Song, Mi-Young;Lee, Young-Rae;Park, Byung-Hyun;Ryu, Do-Gon
    • Journal of Physiology & Pathology in Korean Medicine
    • /
    • v.20 no.4
    • /
    • pp.861-865
    • /
    • 2006
  • Takrisodokyeum (TRSDY) has been known to exert anti-tumoral activity in Korea. However, its molecular mechanism of action is not understood. In this study, we found that TRSDY induced apoptosis in androgen-independent prostate cancer DU145 cells as evidenced by DNA fragmentation and chromatine condensation in hoechst 33342 dye staining. Our data demonstrated that TRSDY-induced apoptotic cell death was accompanied by increases of PTEN and Par-4 in a time-dependent manner Taken together, these results suggest that TRSDY induce PTEN and Par-4 expression, and eventually lead to apoptotic cell death in androgen independent prostate cancer DU145 cells.

MiR-21 Upregulation Induced by Promoter Zone Histone Acetylation is Associated with Chemoresistance to Gemcitabine and Enhanced Malignancy of Pancreatic Cancer Cells

  • Song, Wei-Feng;Wang, Lei;Huang, Wei-Yi;Cai, Xun;Cui, Jiu-Jie;Wang, Li-Wei
    • Asian Pacific Journal of Cancer Prevention
    • /
    • v.14 no.12
    • /
    • pp.7529-7536
    • /
    • 2013
  • Background and Aims: MicroRNA-21 (miR-21) is reported to be overexpressed and to contribute to proliferation, apoptosis and gemcitabine resistance in pancreatic ductal adenocarcinomas (PDACs). The aims of this study were to explore regulation of miR-21 expression by epigenetic change and its impact on chemoresistance and malignant properties of of pancreatic cancer. Materials and methods: We retrospectively collected 41 cases of advanced pancreatic cancer patients who were sensitive or resistant to gemcitabine and assessed levels of serum circulating miR-21 for correlation with cytotoxic activity. Histone acetylation in the miR-21 promoter was also studied in gemcitabine-sensitive and gemcitabine-resistant PDAC cells. Gemcitabine-resistant HPAC and PANC-1 cells were transfected with pre-miR-21 precursors (pre-miR-21) and antisense oligonucleotides (anti-miR-21), and were treated with TSA. Finally, invasion and metastasis assays were performed and alteration in mir-21, PTEN, AKT and pAKT level was evaluated in these cells. Results: Serum miR-21 levels were increased in gemcitabine-resistant PDAC patients compared with gemcitabine-sensitive subjects. The miR-21 levels were increased in 6 PDAC cells treated with gemcitabine significantly, associated with 50% inhibitory concentrations ($IC_{50}s$). Histone acetylation levels at miR-21 promoter were increased in PDAC cells after treatment with gemcitabine. Enhanced invasion and metastasis, increased miR-21 expression, decreased PTEN, elevated pAKT level were demonstrated in gemcitabine-resistant HPAC and PANC-1 cells. Pre-miR-21 transfection or TSA treatment further increased invasion and metastasis ability, decreased PTEN, and elevated pAKT levels in these two lines. In contrast, anti-miR-21 transfection could reverse invasion and metastasis, and PTEN and pAKT expressions induced by gemcitabine. Conclusions: MiR-21 upregulation induced by histone acetylation in the promoter zone is associated with chemoresistance to gemcitabine and enhanced malignant potential in pancreatic cancer cells.

15-Hydroxyeicosatetraenoic Acid Inhibits Phorbol-12-Myristate-13-Acetate-Induced MUC5AC Expression in NCI-H292 Respiratory Epithelial Cells

  • Song, Yong-Seok;Kim, Man Sub;Lee, Dong Hun;Oh, Doek-Kun;Yoon, Do-Young
    • Journal of Microbiology and Biotechnology
    • /
    • v.25 no.5
    • /
    • pp.589-597
    • /
    • 2015
  • It has been reported that overexpression of MUC5AC induced by excessive inflammation leads to airway obstruction in respiratory diseases such as chronic obstructive pulmonary disease and asthma. 15-Hydroxyeicosatetraenoic acid (15-HETE) has been reported to have anti-inflammatory effects, but the role of 15-HETE in respiratory inflammation has not been determined. Therefore, the aim of this study was to investigate the effects of 15-HETE on MUC5AC expression and related pathways. In this study, phorbol-12-myristate-13-acetate (PMA) was used to stimulate NCI-H292 bronchial epithelial cells in order to examine the effects of 15-HETE. 15-HETE inhibited PMA-induced expression of MUC5AC mRNA and secretion of MUC5AC protein. Moreover, 15-HETE regulated matrix metallopeptidase 9 (MMP-9), mitogen-activated protein kinase kinase (MEK), and extracellular signal-regulated kinase (ERK). In addition, 15-HETE decreased the nuclear translocation of specificity protein-1 (Sp-1) transcription factor and nuclear factor κB (NF-κB). Furthermore, 15-HETE enhanced the transcriptional activity of peroxisome proliferator-activated receptor gamma (PPARγ) as a PPARγ agonist. This activity reduced the phosphorylation of protein kinase B (PΚB/Akt) by increasing the expression of phosphatase and tensin homolog (PTEN). In conclusion, 15-HETE regulated MUC5AC expression via modulating MMP-9, MEK/ERK/Sp-1, and PPARγ/PTEN/Akt signaling pathways in PMA-treated respiratory epithelial cells.

COX-2 INHIBITOR INDUCED APOPTOSIS IN ORAL SQUAMOUS CELL CARCINOMA CELL LINE THROUGH AKT PATHWAY (COX-2 억제제에 의한 AKT 경로를 통한 구강편평세포암종 세포주의 세포사멸 유도)

  • Seo, Young-Ho;Han, Se-Jin;Lee, Jae-Hoon
    • Maxillofacial Plastic and Reconstructive Surgery
    • /
    • v.30 no.1
    • /
    • pp.30-40
    • /
    • 2008
  • The objectives of this study was to check up the effect of celecoxib, COX-2 inhibitor, on the pathogenesis of oral squamous cell carcinoma. After mefenamic acid, aspirin and celecoxib, COX-2 inhibitor, were inoculated to HN 22 cell line, the following results were obtained through tumor cell viability by wortmannin, growth curve of tumor cell line, apoptotic index, PGE2 synthesis, total RNA extraction, RT-PCR analysis and TEM features. 1. When wortmannin and celecoxib were given together, the survival rate of tumor cells was lowest about 47 %. So wortmannin had an effect on the decrease of survival rate of tumor cells. 2. In growth curve, the slowest growth was observed in celecoxib inoculated group. 3. The synthesis of PGE2 was decreased in all group and the obvious suppression and highest apoptotic index was observed in celecoxib inoculated group. 4. Suppression of expression of COX-2 mRNA was evident in celecoxib inoculated group. But that of COX-1,2 mRNA was observed in mefenamic acid inoculated group and aspirin inoculated group. 5. In celecoxib inoculated group, mRNA expression of AKT1 was decreased and that of PTEN & expression of caspase 3 and 9 was evidently increased. Depending on above results, when celecoxib was inoculated to oral squamous cell carcinoma cell line, an increase of mRNA expression of caspase 3,9 and PTEN is related to a decrease of mRNA expression of AKT1. Wortmannin had an effect on the decrease of survival rate of tumor cells. Celecoxib might induce apoptosis of tumor cell by suppression of AKT1 pathway and COX-2 inhibition. This results suggested that COX-2 inhibitor might be significantly effective in chemoprevention of oral squamous cell carcinoma.

Peroxisome Proliferator-Activated Receptor-Gamma Agonist 4-O-Methylhonokiol Induces Apoptosis by Triggering the Intrinsic Apoptosis Pathway and Inhibiting the PI3K/Akt Survival Pathway in SiHa Human Cervical Cancer Cells

  • Hyun, Seungyeon;Kim, Man Sub;Song, Yong Seok;Bak, Yesol;Ham, Sun Young;Lee, Dong Hun;Hong, Jintae;Yoon, Do Young
    • Journal of Microbiology and Biotechnology
    • /
    • v.25 no.3
    • /
    • pp.334-342
    • /
    • 2015
  • 4-O-Methylhonokiol (MH), a bioactive compound derived from Magnolia officinalis, is known to exhibit antitumor effects in various cancer cells. However, the precise mechanism of its anticancer activity in cervical cancer cells has not yet been studied. In this study, we demonstrated that MH induces apoptosis in SiHa cervical cancer cells by enhancing peroxisome proliferator-activated receptor-gamma (PPARγ) activation, followed by inhibition of the PI3K/Akt pathway and intrinsic pathway induction. MH upregulated PPARγ and PTEN expression levels while it decreased p-Akt in the MH-induced apoptotic process, thereby supporting the fact that MH is a PPARγ activator. Additionally, MH decreased the expression of Bcl-2 and Bcl-XL, inducing the intrinsic pathway in MH-treated SiHa cells. Furthermore, MH treatment led to the activation of caspase-3/caspase-9 and proteolytic cleavage of polyADP ribose polymerase. The expression levels of Fas (CD95) and E6/E7 oncogenes were not altered by MH treatment. Taken together, MH activates PPARγ/PTEN expression and induces apoptosis via suppression of the PI3K/Akt pathway and mitochondria-dependent pathways in SiHa cells. These findings suggest that MH has potential for development as a therapeutic agent for human cervical cancer.