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Currier N, Solomon SE, Demicco EG, Chang DLF, Farago M, Ying H, Dominguez I, Sonenshein GE, Cardiff RD, Xiao ZXJ, Sherr DH, Seldin DC. Oncogenic Signaling Pathways Activated in DMBA-Induced Mouse Mammary Tumors. Toxicol Pathol 2017; 33:726-37. [PMID: 16263698 DOI: 10.1080/01926230500352226] [Citation(s) in RCA: 116] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Only about 5% of human breast cancers can be attributed to inheritance of breast cancer susceptibility genes, while the balance are considered to be sporadic in origin. Breast cancer incidence varies with diet and other environmental influences, including carcinogen exposure. However, the effects of environmental carcinogens on cell growth control pathways are poorly understood. Here we have examined oncogenic signaling pathways that are activated in mammary tumors in mice treated with the prototypical polycyclic aromatic hydrocarbon (PAH) 7,12-dimethylbenz[ a]anthracene (DMBA). In female FVB mice given 6 doses of 1 mg of DMBA by weekly gavage beginning at 5 weeks of age, all of the mice developed tumors by 34 weeks of age (median 20 weeks after beginning DMBA); 75% of the mice had mammary tumors. DMBA-induced mammary tumors exhibited elevated expression of the aryl hydrocarbon receptor (AhR), c- myc, cyclin D1, and hyperphosphorylated retinoblastoma (Rb) protein. Because of this, the activation of upstream regulatory pathways was assessed, and elements of the Wnt signaling pathway, the NF-κB pathway, and the prolyl isomerase Pin-1 were found to be frequently up-regulated in the tumors when compared to normal mammary gland controls. These data suggest that environmental carcinogens can produce long-lasting alterations in growth and anti-apoptotic pathways, leading to mammary tumorigenesis.
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MESH Headings
- 9,10-Dimethyl-1,2-benzanthracene
- Animals
- Apoptosis/drug effects
- Carcinogens
- Casein Kinase II/metabolism
- DNA/metabolism
- Female
- Gene Expression Regulation, Neoplastic/drug effects
- Genes, bcl-1/drug effects
- Genes, bcl-1/physiology
- Genes, myc/drug effects
- Genes, myc/physiology
- Mammary Neoplasms, Experimental/chemically induced
- Mammary Neoplasms, Experimental/genetics
- Mammary Neoplasms, Experimental/metabolism
- Mice
- NF-kappa B/metabolism
- NIMA-Interacting Peptidylprolyl Isomerase
- Oncogenes/drug effects
- Oncogenes/physiology
- Peptidylprolyl Isomerase/metabolism
- RNA, Messenger/metabolism
- Receptors, Aryl Hydrocarbon/genetics
- Receptors, Aryl Hydrocarbon/metabolism
- Retinoblastoma Protein/metabolism
- Signal Transduction/drug effects
- Wnt Proteins/metabolism
- beta Catenin/metabolism
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Affiliation(s)
- Nicolas Currier
- Boston University School of Medicine, Department of Medicine, Boston, MA, USA
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Shimizu Y, Takeuchi T, Mita S, Notsu T, Mizuguchi K, Kyo S. Krüppel-like factor 4 mediates anti-proliferative effects of progesterone with G₀/G₁ arrest in human endometrial epithelial cells. J Endocrinol Invest 2010; 33:745-50. [PMID: 20479568 DOI: 10.1007/bf03346681] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Activation of the progesterone receptor (PR) inhibits cell proliferation in various reproductive tissues. However, the molecular mechanisms underlying the regulation of cell proliferation by PR remain poorly understood. It is well established that Krüppel-like factor 4 (KLF4), a family of zinc fingercontaining transcription factors, induces cell cycle arrest in epithelial cells. In this study, we investigated whether KLF4 served as a target of PR activation during cell proliferation using human endometrial epithelial cells. PR agonists, progesterone and dienogest, were found to produce a lasting increase in the expression of KLF4 mRNA, followed by a decrease in cyclin D1 mRNA, and inhibit cell proliferation with G₀/G₁ arrest. KLF4 knockdown using KLF4 small interferingRNA abrogated the inhibition of cell proliferation by PR agonists. In addition, forced expression of KLF4 inhibited cyclin D1 promoter transactivation. These results suggest that PR agonists induce KLF4 expression and then inhibit cyclin D1 expression, and consequently inhibit cell proliferation in human endometrial epithelial cells. In terms of human reproductive tissue, KLF4 may be a factor concerning cell cycle, directly responsive to PR activation.
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Affiliation(s)
- Y Shimizu
- Pharmaceutical Research Center, Mochida Pharmaceutical Co., Ltd., 722 Jimba-aza-Uenohara, Gotemba, Shizuoka 412-8524, Japan.
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4
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Kowara R, Karaczyn A, Cheng RYS, Salnikow K, Kasprzak KS. Microarray analysis of altered gene expression in murine fibroblasts transformed by nickel(II) to nickel(II)-resistant malignant phenotype. Toxicol Appl Pharmacol 2005; 205:1-10. [PMID: 15885260 DOI: 10.1016/j.taap.2004.10.006] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2004] [Accepted: 10/12/2004] [Indexed: 11/29/2022]
Abstract
B200 cells are Ni(II)-transformed mouse BALB/c-3T3 fibroblasts displaying a malignant phenotype and increased resistance to Ni(II) toxicity. In an attempt to find genes whose expression has been altered by the transformation, the Atlas Mouse Stress/Toxicology cDNA Expression Array (Clontech Laboratories, Inc., Palo Alto, CA) was used to analyze the levels of gene expression in both parental and Ni(II)-transformed cells. Comparison of the results revealed a significant up- or downregulation of the expression of 62 of the 588 genes present in the array (approximately 10.5%) in B200 cells. These genes were assigned to different functional groups, including transcription factors and oncogenes (9/14; fractions in parentheses denote the number of up-regulated versus the total number of genes assigned to this group), stress and DNA damage response genes (11/12), growth factors and hormone receptors (6/9), metabolism (7/7), cell adhesion (2/7), cell cycle (3/6), apoptosis (3/4), and cell proliferation (2/3). Among those genes, overexpression of beta-catenin and its downstream targets c-myc and cyclin D1, together with upregulated cyclin G, points at the malignant character of B200 cells. While the increased expression of glutathione (GSH) synthetase, glutathione-S-transferase A4 (GSTA4), and glutathione-S-transferase theta (GSTT), together with high level of several genes responding to oxidative stress, suggests the enforcement of antioxidant defenses in Ni-transformed cells.
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MESH Headings
- Animals
- Apoptosis/drug effects
- Apoptosis/genetics
- Cell Adhesion/drug effects
- Cell Adhesion/genetics
- Cell Line, Transformed
- Cell Line, Tumor
- Cell Proliferation/drug effects
- Cyclin G
- Cyclin G1
- Cyclins/drug effects
- Cyclins/genetics
- Cyclins/metabolism
- Cyclooxygenase 1
- Cyclooxygenase 2
- Cytoskeletal Proteins/genetics
- Cytoskeletal Proteins/metabolism
- Cytoskeletal Proteins/pharmacology
- DNA Damage/drug effects
- DNA Damage/genetics
- Fibroblasts/drug effects
- Fibroblasts/pathology
- Fibroblasts/physiology
- Gene Expression Profiling/methods
- Gene Expression Regulation/drug effects
- Gene Expression Regulation/genetics
- Genes, bcl-1/drug effects
- Genes, bcl-1/physiology
- Genes, cdc/drug effects
- Genes, myc/drug effects
- Genes, myc/physiology
- Glutathione/genetics
- Glutathione/metabolism
- Glutathione Synthase/drug effects
- Glutathione Synthase/genetics
- Glutathione Synthase/metabolism
- Glutathione Transferase/drug effects
- Glutathione Transferase/genetics
- Glutathione Transferase/metabolism
- Growth Substances/genetics
- Growth Substances/metabolism
- Isoenzymes
- Membrane Proteins
- Mice
- Mice, Inbred BALB C
- Microarray Analysis/methods
- Microarray Analysis/trends
- Nickel/adverse effects
- Oncogenes/drug effects
- Oncogenes/genetics
- Oxidative Stress/drug effects
- Oxidative Stress/genetics
- Phenotype
- Prostaglandin-Endoperoxide Synthases/drug effects
- Prostaglandin-Endoperoxide Synthases/genetics
- Trans-Activators/genetics
- Trans-Activators/metabolism
- Trans-Activators/pharmacology
- Transcription Factors, General/drug effects
- Transcription Factors, General/genetics
- Transcription Factors, General/metabolism
- beta Catenin
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Affiliation(s)
- Renata Kowara
- Laboratory of Comparative Carcinogenesis, National Cancer Institute at Frederick, MD 21702, USA.
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Cohen S, Dovrat S, Sarid R, Huberman E, Salzberg S. JAK-STAT signaling involved in phorbol 12-myristate 13-acetate- and dimethyl sulfoxide-induced 2'-5' oligoadenylate synthetase expression in human HL-60 leukemia cells. Leuk Res 2005; 29:923-31. [PMID: 15978943 DOI: 10.1016/j.leukres.2005.01.015] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2004] [Revised: 01/20/2005] [Accepted: 01/31/2005] [Indexed: 10/25/2022]
Abstract
The JAK-STAT signal transduction cascade participates in various cellular processes, including immune response, cell replication, differentiation and oncogenesis. Here, we report that this cascade is induced in two human myeloid HL-60 leukemia cell variants by the granulocyte differentiation inducer dimethyl sulfoxide (DMSO) and macrophage differentiation inducer phorbol 12-myristate 13-acetate (PMA). DMSO and PMA also induced the expression and catalytic activity of 2'-5' oligoadenylate synthetase (2-5A synthetase), a known interferon (IFN) inducible enzyme. The HL-60 cell variants included HL-205, which is susceptible to DMSO- and PMA-induced differentiation, and HL-525, which is susceptible to DMSO- but not to PMA-induced differentiation. Treatment of HL-205 and HL-525 cells with DMSO and HL-205 cells with PMA-induced JAK1 phosphorylation, JAK1/STAT1 association, formation of STAT1-STAT2 heterodimers, and the binding of the active IFN stimulating growth factor 3 (ISGF3) to the IFN-stimulated response element (ISRE) fragment isolated from the 2-5A synthetase promoter. These events were either reduced or absent in the resistant HL-525 cells treated with PMA. Taken together, our data implicate the above signaling cascade in DMSO- and PMA-induced 2-5A synthetase expression and catalytic activity in the HL-60 cell system.
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Affiliation(s)
- Shenhav Cohen
- Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 52900, Israel
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Bose B, Gour RR, Motiwale L, Gupta S, Rao KVK. Hyperphosphorylation of extracellular regulated kinase 2 (ERK2) and inhibition of JNK2 phosphorylation are associated with increased S-phase during transformation of Syrian hamster embryo cells by Malachite Green. Cell Biol Int 2004; 28:875-83. [PMID: 15566957 DOI: 10.1016/j.cellbi.2004.09.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2004] [Revised: 07/26/2004] [Accepted: 09/03/2004] [Indexed: 11/29/2022]
Abstract
Malachite Green (MG), consisting of green crystals with a metallic lustre, is highly soluble in water, cytotoxic to various mammalian cells and also acts as a liver tumour promoter. In view of its industrial importance and possible exposure to human beings, MG poses a potential environmental health hazard. We have earlier reported the malignant transformation of Syrian hamster embryo (SHE) cells in primary culture by MG. In this study, we have studied the mitogen activated protein (MAP) kinase signal transduction pathway in preneoplastic cells induced by MG. Western blots of MG induced preneoplastic cells showed no phosphorylation of ERK1, an increased phosphoactive ERK2 associated with a decreased expression of phosphoactive JNK2. However, total forms of ERKs, JNKs and p38 Kinases showed similar levels of expression in control and preneoplastic SHE cells. Indirect immunofluorescence studies have shown a distinct nuclear localisation of phosphoactive ERKs in MG induced preneoplastic cells. Flow cytometric analysis showed an increase of S-phase cells in preneoplastic cells compared to control SHE cells. The present study indicates that hyperphosphorylation of ERK2, decreased JNK2 phosphorylation and an increase in S-phase cells seems to be the early changes associated with the MG induced malignant transformation of SHE cells in primary culture.
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Affiliation(s)
- Bipasha Bose
- Chemical Carcinogenesis Group, Cancer Research Institute, Advanced Centre for Treatment Research and Education in Cancer (ACTREC), Tata Memorial Centre, Kharghar, Navi Mumbai 410 208, India
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Abstract
In this study, we investigated the effects of estradiol on the proliferation of neonatal keratinocytes, the expression of estrogen receptor isoforms, and the signaling mechanisms by which estradiol mediates cell growth. We demonstrate that estradiol binds neonatal keratinocytes with high affinity (Kd=5.2nM) and limited capacity (Bmax of 14.2fmol/mg of protein), confirming the presence of estrogen binding sites. Using specific antibodies, we demonstrate that keratinocytes express both estrogen receptor (ER)-alpha and ER-beta. At physiological concentrations, estradiol up-regulates the level of ER-alpha receptors in keratinocytes and induces keratinocyte proliferation. The proliferative effect of estradiol requires the availability of functional estrogen receptors, as it is abrogated by anti-estrogen administration. Estradiol effect on keratinocyte proliferation is most likely mediated in part by activation of a nongenomic, membrane-associated, signaling pathway involving activation of the extracellular signal regulated kinases 1 and 2 and in part by the genomic signaling pathway through activation of nuclear receptors.
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Affiliation(s)
- S Verdier-Sevrain
- Department of Dermatology, Boston University School of Medicine, Boston, Massachusetts 02118-2394, USA
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8
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Simile MM, De Miglio MR, Muroni MR, Frau M, Asara G, Serra S, Muntoni MD, Seddaiu MA, Daino L, Feo F, Pascale RM. Down-regulation of c-myc and Cyclin D1 genes by antisense oligodeoxy nucleotides inhibits the expression of E2F1 and in vitro growth of HepG2 and Morris 5123 liver cancer cells. Carcinogenesis 2003; 25:333-41. [PMID: 14604889 DOI: 10.1093/carcin/bgh014] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
A number of genetic interactions are involved in the control of cell cycle, but their role and nature have not been completely clarified. The knowledge of the behavior of these interactions in hepatocellular carcinoma, could optimize preventive and therapeutic strategies based on cell cycle restraint. We studied downstream events following c-MYC and CYCLIN D1 gene inhibition, by lipoplex-delivered MYC and CYCLIN D1 antisense oligodeoxy nucleotides (aODNM, aODND1), in in vitro cultured human HepG2 and rat Morris 5123 hepatoma cells. 0.5-20 micro M aODN(M) and aODND1 inhibited in vitro growth of both cell types. Scramble oligomer (SCR) and sense ODNs had no or relatively poor effect. Ten micromolar aODNM and aODND1, but not SCR, also induced a significant increase in the apoptotic index of HepG2 and 5123 cells, and inhibited colony formation in soft agar by HepG2 cells. Treatment of the cells with aODNM plus aODND1 had no additive effect on growth and apoptosis. aODNM and aODND1 induced >50% decrease in c-MYC and CYCLIN D1 gene expression, respectively, at both mRNA and protein level. The inhibition of gene expression by aODNs was highly specific, and SCR was without effect. The reduction in c-MYC and CYCLIN D1 expression by aODNs, was associated with a >50% decrease in E2F1 mRNA and protein production, without changes in CYCLIN A and CYCLIN E expression. These results suggest the involvement of both c-MYC and CYCLIN D1 on E2F1 gene function, and indicate that aODNM and aODND1 may inhibit hepatoma cell growth through down-regulation of the E2F1 gene. The inhibition of E2F1 gene expression by E2F1 aODN, was associated with strong growth restraint of HepG2 cells. Thus, interactions of c-MYC and CYCLIN D1 with E2F1 gene are essential for cell cycle activity in hepatoma cells, and their inhibition may have a therapeutic effect.
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Affiliation(s)
- Maria M Simile
- Department of Biomedical Sciences, Division of Experimental Pathology and Oncology, University of Sassari, I-07100 Sassari, Italy
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Natsume H, Sasaki S, Kitagawa M, Kashiwabara Y, Matsushita A, Nakano K, Nishiyama K, Nagayama K, Misawa H, Masuda H, Nakamura H. Beta-catenin/Tcf-1-mediated transactivation of cyclin D1 promoter is negatively regulated by thyroid hormone. Biochem Biophys Res Commun 2003; 309:408-13. [PMID: 12951064 DOI: 10.1016/j.bbrc.2003.08.019] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Cyclin D1 is an oncogenic cyclin frequently over-expressed in cancer. To examine the effect of thyroid hormone (T3) and its receptor (TR) on the transcription of cyclin D1 gene, we co-transfected the chloramphenicol acetyl-transferase (CAT) reporter plasmid containing cyclin D1 promoter together with the expression plasmids for TRbeta1 and wild-type or mutant beta-catenin (SA) into 293T cells. In the presence of T3, beta-catenin-dependent transactivation of cyclin D1 promoter was suppressed by co-transfection of TRbeta1. The suppression by T3/TRbeta1 was in a dose-dependent manner. The CAT reporter gene in which Tcf/Lef-1 sites were fused to heterologous promoter was also suppressed by T3/TRbeta1. Furthermore, inhibition of endogenous wild-type beta-catenin by T3/TRbeta1 was observed in SW480 colon carcinoma cells with mutation of the adenomatous polyposis coli gene. These results indicate that the T3-bound TR inhibits the transcription of cyclin D1 through the Tcf/Lef-1 site, which is positively regulated by the Wnt-signaling pathway.
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Affiliation(s)
- Hiroko Natsume
- Second Division of Internal Medicine, Hamamatsu University School of Medicine, Hamamatsu, Shizuoka 431-3192, Japan
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Abstract
The thyroid hormone (T3) blocks proliferation and induces differentiation of neuroblastoma N2a-beta cells that overexpress the beta 1 isoform of the T3 receptor. An element in the region responsible for premature termination of transcription mediates a rapid repression of c-myc gene expression by T3. The hormone also causes a decrease of cyclin D1 gene transcription, and is able to antagonize the activation of the cyclin D1 promoter by Ras. In addition, a strong and sustained increase of the levels of the cyclin kinase inhibitor (CKI) p27(Kip1) are found in T3-treated cells. The increased levels of p27(Kip1) lead to a marked inhibition of the kinase activity of the cyclin-CDK2 complexes. As a consequence of these changes, retinoblastoma proteins are hypophosphorylated in T3-treated N2a-beta cells, and progression through the restriction point in the cell cycle is blocked.
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Affiliation(s)
- Susana Garcia-Silva
- Instituto de Investigaciones Biomédicas Alberto Sols, CSIC-UAM, Arturo Duperier 4, 28029 Madrid, Spain
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Lee KT, Sohn IC, Kim YK, Choi JH, Choi JW, Park HJ, Itoh Y, Miyamoto K. Tectorigenin, an isoflavone of Pueraria thunbergiana Benth., induces differentiation and apoptosis in human promyelocytic leukemia HL-60 cells. Biol Pharm Bull 2001; 24:1117-21. [PMID: 11642314 DOI: 10.1248/bpb.24.1117] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Cytotoxic effects of six isoflavonoids, tectorigenin, glycitein, tectoridin, glycitin, 6''-O-xylosyltectoridin, and 6''-O-xylosylglycitin isolated from the flower of Pueraria thunbergiana Benth. together with genistein, a known differentiation and apoptosis inducer, were examined. Among these isoflavonoids, tectorigenin and genistein exhibited cytotoxicity against various human cancer cells; glycitein showed only mild cytotoxicity. These results suggest that the isoflavone structure and 5-hydroxyl group are crucial for the cytotoxic properties and that glycosides are inactive. Moreover, tectorigenin induced differentiation of human promyelocytic leukemia HL-60 cells to granulocytes and monocytes/macrophages, and caused apoptotic changes of DNA in the cells, as did genistein. Tectorigenin also inhibited autophosphorylation of epidermal growth factor (EGF) receptor by EGF and decreased the expression of Bcl-2 protein, with less activity than genistein. From these results, tectorigenin may be a possible therapeutic agent for leukemia.
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Affiliation(s)
- K T Lee
- College of Pharmacy, Kyung Hee University, Seoul, Korea
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Minko T, Kopecková P, Kopecek J. Preliminary evaluation of caspases-dependent apoptosis signaling pathways of free and HPMA copolymer-bound doxorubicin in human ovarian carcinoma cells. J Control Release 2001; 71:227-37. [PMID: 11295216 DOI: 10.1016/s0168-3659(01)00220-6] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The purpose of the study was to examine the role of caspases in signaling pathways of apoptosis induced by free doxorubicin (DOX) and HPMA copolymer-bound DOX (P(GFLG)-DOX) in human ovarian carcinoma cells. Sensitive A2780 and DOX resistant A2780/AD cells were exposed to different doses of drugs within 12, 18, 24 and 36 h. Caspase activity, expression of genes encoding human caspases 1-10, Apaf-1 and bcl-2 proteins and apoptosis were studied. In sensitive cells both free and P(GFLG)-DOX activated caspases 3, 7 and 9. In addition, P(GFLG)-DOX activated caspases 6 and 8. In resistant cells apoptosis induced by free DOX depended on the activation of caspases 2, 7 and 9, while caspase 3 was not involved; this explains the low degree of apoptosis induced by free DOX in resistant cells. P(GFLG)-DOX triggered the additional caspases 3, 6 and 8. A more pronounced degree of caspase activation and apoptosis after the action of P(GFLG)-DOX depended on the inhibition of bcl-2-encoded cellular defensive mechanisms and a more significant activation of Apaf-1. It was concluded that HPMA copolymer-bound DOX induced additional caspase-dependent apoptosis signaling pathways and the degree of the induction was higher, which led to more pronounced apoptosis when compared to free DOX.
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Affiliation(s)
- T Minko
- Department of Pharmaceutics and Pharmaceutical Chemistry, University of Utah, 30 South 2000 East, Rm. 301, Salt Lake City, UT 84112, USA
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Lavie G, Kaplinsky C, Toren A, Aizman I, Meruelo D, Mazur Y, Mandel M. A photodynamic pathway to apoptosis and necrosis induced by dimethyl tetrahydroxyhelianthrone and hypericin in leukaemic cells: possible relevance to photodynamic therapy. Br J Cancer 1999; 79:423-32. [PMID: 10027308 PMCID: PMC2362416 DOI: 10.1038/sj.bjc.6690066] [Citation(s) in RCA: 73] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The mechanism of cell death induction by dimethyl tetrahydroxyhelianthrone (DTHe), a new second-generation photodynamic sensitizer, is analysed in human leukaemic cell lines in comparison with the structurally related hypericin. DTHe has a broad range of light spectrum absorption that enables effective utilization of polychromatic light. Photosensitization of HL-60 cells with low doses of DTHe (0.65 microM DTHe and 7.2 J cm(-2) light energy) induced rapid apoptosis of > or =90% of the cells. At doses > or =2 microM, dying cells assumed morphological necrosis with perinucleolar condensation of chromatin in HL-60 and K-562 cell lines. Although nuclear fragmentation that is characteristic to apoptosis was prevented, DNA digestion to oligonucleosomes proceeded unhindered. Such incomplete apoptosis was more prevalent with the related analogue hypericin throughout most doses of photosensitization. Despite hypericin being a stronger photosensitizer, DTHe exhibited advantageous phototoxic properties to tumour cells, initiating apoptosis at concentrations about threefold lower than hypericin. Photosensitization of the cells induced dissociation of the nuclear envelope, releasing lamins into the cytosol. DTHe also differed from hypericin in effects exerted on the nuclear lamina, causing release of an 86-kDa lamin protein into the cytosol that was unique to DTHe. Within the nucleus, nuclear envelope lamin B underwent covalent polymerization, which did not affect apoptotic nuclear fragmentation at low doses of DTHe. At higher doses, polymerization may have been extensive enough to prevent nuclear collapse. Hut-78, CD4+ cells were resistant to the photodynamically activated apoptotic pathway. Beyond the tolerated levels of photodynamic damage, these cells died exclusively via necrosis. Hut-78 cells overexpress Bcl-X(L) as well as a truncated Bcl-X(L)tr isoform that could contribute to the observed resistance to apoptosis.
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Affiliation(s)
- G Lavie
- Institute of Hematology, Blood Transfusion Center, Sheba Medical Center, Tel-Hashomer, Israel
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Abstract
We examined the effects of all-trans retinoic acid (RA) on the insulin-induced cell growth, cell cycle progression and cyclin D1 gene expression in breast cancer cells. RA exerted a dose-dependent growth inhibition on insulin-induced proliferation in T47D and MCF-7 hormone-dependent cell lines, whereas MDA-MB231 hormone-independent cells were not affected. The RA antagonism of insulin growth effect was associated with an inhibition of cell cycle progression and a suppression of insulin-induced cyclin D1 mRNA. The effect of RA on cyclin D1 mRNA was dose-dependent and was observed within 5 h of treatment when insulin response was maximal.
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Affiliation(s)
- S Bardon
- Institut National de la Recherche Agronomique, Laboratoire de Nutrition et Securite Alimentaire, Jouy-en-Josas, 78352, France
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