| 1. |
- Hombach-Klonisch, Sabine, et al.
(författare)
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Cancer stem cells as targets for cancer therapy : selected cancers as examples
- 2008
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Ingår i: Archivum Immunologiae et Therapiae Experimentalis. - : Springer Science and Business Media LLC. - 0004-069X .- 1661-4917. ; 56:3, s. 165-180
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Forskningsöversikt (refereegranskat)abstract
- It is becoming increasingly evident that cancer constitutes a group of diseases involving altered stem-cell maturation/differentiation and the disturbance of regenerative processes. The observed malignant transformation is merely a symptom of normal differentiation processes gone astray rather than the primary event. This review focuses on the role of cancer stem cells (CSCs) in three common but also relatively under-investigated cancers: head and neck, ovarian, and testicular cancer. For didactic purpose, the physiology of stem cells is first introduced using hematopoietic and mesenchymal stem cells as examples. This is followed by a discussion of the (possible) role of CSCs in head and neck, ovarian, and testicular cancer. Aside from basic information about the pathophysiology of these cancers, current research results focused on the discovery of molecular markers specific to these cancers are also discussed. The last part of the review is largely dedicated to signaling pathways active within various normal and CSC types (e.g. Nanog, Nestin, Notch1, Notch2, Oct3 and 4, Wnt). Different elements of these pathways are also discussed in the context of therapeutic opportunities for the development of targeted therapies aimed at CSCs. Finally, alternative targeted anticancer therapies arising from recently identified molecules with cancer-(semi-)selective capabilities (e.g. apoptin, Brevinin-2R) are considered.
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| 2. |
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| 3. |
- Bauer, M. K. A., et al.
(författare)
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Role of reactive oxygen intermediates in activation-induced CD95 (APO-1/Fas) ligand expression
- 1998
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Ingår i: Journal of Biological Chemistry. - : Elsevier BV. - 0021-9258 .- 1083-351X. ; 273:14, s. 8048-8055
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Tidskriftsartikel (refereegranskat)abstract
- Activation-induced cell death of T lymphocytes requires the inducible expression of CD95 (APO-1/Fas) ligand, which triggers apoptosis in CD95-bearing target cells by an autocrine or paracrine mechanism. Although execution of the CD95 death pathway is largely independent of reactive oxygen intermediates, activation-induced cell death is blocked by a variety of antioxidants. In the present study, we investigated the involvement of redox processes in the regulation of CD95 ligand (CD95L) expression in Jurkat T cells. We show that various antioxidants potently inhibited the transcriptional activation of CD95L following T cell receptor litigation or stimulation of cells with phorbol ester and ionomycin. Conversely, a prooxidant such as hydrogen peroxide alone was able to increase CD95L expression. As detected by Western blot and cytotoxicity assays, functional expression of CD95L protein was likewise diminished by antioxidants. Inhibition of CD95L expression was associated with a decreased DNA binding activity of nuclear factor (NF)-kappa B, an important redox-controlled transcription factor. Moreover, inhibition of NF-kappa B activity by a transdominant I kappa B mutant attenuated CD95L expression. Our data suggest that, although reactive oxygen intermediates do not act as mediators in the execution phase of CD95-mediated apoptosis, they are involved in the transcriptional regulation of CD95L expression.
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| 4. |
- Burek, C. J., et al.
(författare)
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The role of ceramide in receptor- and stress-induced apoptosis studied in acidic ceramidase-deficient Farber disease cells
- 2001
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Ingår i: Oncogene. - : Nature Publishing Group. - 0950-9232 .- 1476-5594. ; 20:45, s. 6493-6502
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Tidskriftsartikel (refereegranskat)abstract
- The activation of sphingomyelinases leading to the generation of ceramide has been implicated in various apoptotic pathways. However, the role of ceramide as an essential death mediator remains highly controversial. In the present study, we investigated the functional relevance of ceramide in a genetic model by using primary cells from a Farber disease patient. These cells accumulate ceramide as the result of an inherited deficiency of acidic ceramidase. We demonstrate that Farber disease lymphocytes and fibroblasts underwent apoptosis induced by various stress stimuli, including staurosporine, anticancer drugs and gamma -irradiation, equally as normal control cells. In addition, caspase activation by these proapoptotic agents occurred rather similarly in Farber disease and control fibroblasts. Interestingly, Farber disease lymphoid cells underwent apoptosis induced by the CD95 death receptor more rapidly than control cells. Our data therefore suggest that ceramide does not play an essential role as a second messenger in stress-induced apoptosis. However, in accordance with a role in lipid-rich microdomains, ceramide by altering membrane composition may function as an amplifier in CD95-mediated apoptosis.
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| 5. |
- Burek, M., et al.
(författare)
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Apoptin-induced cell death is modulated by Bcl-2 family members and is Apaf-1dependent
- 2006
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Ingår i: Oncogene. - : Springer Science and Business Media LLC. - 0950-9232 .- 1476-5594. ; 25:15, s. 2213-2222
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Tidskriftsartikel (refereegranskat)abstract
- Apoptin, a chicken anemia virus-derived protein, selectively induces apoptosis in transformed but not in normal cells, thus making it a promising candidate as a novel anticancer therapeutic. The mechanism of apoptin-induced apoptosis is largely unknown. Here, we report that contrary to previous assumptions, Bcl-2 and Bcl-x(L) inhibit apoptin-induced cell death in several tumor cell lines. In contrast, deficiency of Bax conferred resistance, whereas Bax expression sensitized cells to apoptin-induced death. Cell death induction by apoptin was associated with cytochrome c release from mitochondria as well as with caspase-3 and -7 activation. Benzyloxy-carbonyl-Val-Ala-Asp-fluoromethyl ketone, a broad spectrum caspase inhibitor, was highly protective against apoptin-induced cell death. Apoptosis induced by apoptin required Apaf-1, as immortalized Apaf-1-deficient fibroblasts as well as tumor cells devoid of Apaf-1 were strongly protected. Thus, our data indicate that apoptin-induced apoptosis is not only Bcl-2- and caspase dependent, but also engages an Apaf-1 apoptosome-mediated mitochondrial death pathway.
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| 6. |
- Chlichlia, K., et al.
(författare)
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Redox events in HTLV-1 tax-induced apoptotic T-cell death
- 2002
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Ingår i: Antioxidants and Redox Signaling. - : Mary Ann Liebert, Inc. publishers. - 1523-0864 .- 1557-7716. ; 4:3, s. 471-477
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Tidskriftsartikel (refereegranskat)abstract
- A number of studies implicate reactive oxygen intermediates in the induction of DNA damage and apoptosis. Recent studies suggest that the human T-cell leukemia virus type I (HTLV-1) Tax protein induces oxidative stress and apoptotic T-cell death. Activation of the T-cell receptor/CD3 pathway enhances the Tax-mediated oxidative and apoptotic effects. Tax-mediated apoptosis and oxidative stress as well as activation of nuclear factor-kappaB can be potently suppressed by antioxidants. This review focuses on Tax-dependent changes in the intracellular redox status and their role in Tax-mediated DNA damage and apoptosis. The relevance of these observations to HTLV-1 virus-mediated T-cell transformation and leukemogenesis are discussed.
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| 7. |
- Ferrari, D., et al.
(författare)
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Differential regulation and ATP requirement for caspase-8 and caspase-3 activation during CD95- and anticancer drug-induced apoptosis
- 1998
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Ingår i: Journal of Experimental Medicine. - : Rockefeller University Press. - 0022-1007 .- 1540-9538. ; 188:5, s. 979-984
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Tidskriftsartikel (refereegranskat)abstract
- Apoptosis is induced by different stimuli, among them triggering of the death receptor CD95, staurosporine, and chemotherapeutic drugs. In all cases, apoptosis is mediated by caspases, although it is unclear how these diverse apoptotic stimuli cause protease activation. Two regulatory pathways have been recently identified, but it remains unknown whether they are functionally independent or linked to each other. One is mediated by recruitment of the proximal regulator caspase-8 to the death receptor complex. The other pathway is controlled by the release of cytochrome c from mitochondria and the subsequent ATP-dependent activation of the death regulator apoptotic protease-activating factor 1 (Apaf-1). Here, we report that both pathways can be dissected by depletion of intracellular ATP. Prevention of ATP production completely inhibited caspase activation and apoptosis in response to chemotherapeutic drugs and staurosporine. Interestingly, caspase-8, whose function appeared to be restricted to death receptors, was also activated by these drugs under normal conditions, but not after ATP depletion. In contrast, inhibition of ATP production did not affect caspase activation after triggering of CD95. These results suggest that chemotherapeutic drug-induced caspase activation is entirely controlled by a receptor-independent mitochondrial pathway, whereas CD95-induced apoptosis can be regulated by a separate pathway not requiring Apaf-1 function.
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| 8. |
- Ghavami, Saeid, et al.
(författare)
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S100A8/9 induces cell death via a novel, RAGE-independent pathway that involves selective release of Smac/DIABLO and Omi/HtrA2
- 2008
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Ingår i: Biochimica et Biophysica Acta. Molecular Cell Research. - : Elsevier. - 0167-4889 .- 1879-2596. ; 1783:2, s. 297-311
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Tidskriftsartikel (refereegranskat)abstract
- A complex of two S100 EF-hand calcium-binding proteins S100A8/A9 induces apoptosis in various cells, especially tumor cells. Using several cell lines, we have shown that S100A8/A9-induced cell death is not mediated by the receptor for advanced glycation endproducts (RAGE), a receptor previously demonstrated to engage S100 proteins. Investigation of cell lines either deficient in, or over-expressing components of the death signaling machinery provided insight into the S100A8/A9-mediated cell death pathway. Treatment of cells with S100A8/A9 caused a rapid decrease in the mitochondrial membrane potential (ΔΨm) and activated Bak, but did not cause release of apoptosis-inducing factor (AIF), endonuclease G (Endo G) or cytochrome c. However, both Smac/DIABLO and Omi/HtrA2 were selectively released into the cytoplasm concomitantly with a decrease in Drp1 expression, which inhibits mitochondrial fission machinery. S100A8/A9 treatment also resulted in decreased expression of the anti-apoptotic proteins Bcl2 and Bcl-XL, whereas expression of the pro-apoptotic proteins Bax, Bad and BNIP3 was not altered. Over-expression of Bcl2 partially reversed the cytotoxicity of S100A8/A9. Together, these data indicate that S100A8/A9-induced cell death involves Bak, selective release of Smac/DIABLO and Omi/HtrA2 from mitochondria, and modulation of the balance between pro- and anti-apoptotic proteins.
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| 9. |
- Hombach-Klonisch, Sabine, et al.
(författare)
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Adult stem cells and their trans-differentiation potential-perspectives and therapeutic applications
- 2008
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Ingår i: Journal of Molecular Medicine. - : Springer. - 0946-2716 .- 1432-1440. ; 86:12, s. 1301-1314
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Tidskriftsartikel (refereegranskat)abstract
- Stem cells are self-renewing multipotent progenitors with the broadest developmental potential in a given tissue at a given time. Normal stem cells in the adult organism are responsible for renewal and repair of aged or damaged tissue. Adult stem cells are present in virtually all tissues and during most stages of development. In this review, we introduce the reader to the basic information about the field. We describe selected stem cell isolation techniques and stem cell markers for various stem cell populations. These include makers for endothelial progenitor cells (CD146/MCAM/MUC18/S-endo-1, CD34, CD133/prominin, Tie-2, Flk1/KD/VEGFR2), hematopoietic stem cells (CD34, CD117/c-Kit, Sca1), mesenchymal stem cells (CD146/MCAM/MUC18/S-endo-1, STRO-1, Thy-1), neural stem cells (CD133/prominin, nestin, NCAM), mammary stem cells (CD24, CD29, Sca1), and intestinal stem cells (NCAM, CD34, Thy-1, CD117/c-Kit, Flt-3). Separate section provides a concise summary of recent clinical trials involving stem cells directed towards improvement of a damaged myocardium. In the last part of the review, we reflect on the field and on future developments.
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| 10. |
- Klonisch, Thomas, et al.
(författare)
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Cancer stem cell markers in common cancers - therapeutic implications
- 2008
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Ingår i: Trends in Molecular Medicine. - : Elsevier. - 1471-4914 .- 1471-499X. ; 14:10, s. 450-460
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Forskningsöversikt (refereegranskat)abstract
- Rapid advances in the cancer stem cell (CSC) field have provided cause for optimism for the development of more reliable cancer therapies in the future. Strategies aimed at efficient targeting of CSCs are becoming important for monitoring the progress of cancer therapy and for evaluating new therapeutic approaches. Here, we characterize and compare the specific markers that have been found to be present on stem cells, cancer cells and CSCs in selected tissues (colon, breast, liver, pancreas and prostate). We then discuss future directions of this intriguing new research field in the context of new diagnostic and therapeutic opportunities.
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