| 1. |
- Palm, Maria E, et al.
(författare)
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Cisplatin binds human copper chaperone Atox1 and promotes unfolding in vitro.
- 2011
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 108:17, s. 6951-6
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Tidskriftsartikel (refereegranskat)abstract
- Cisplatin (cisPt), Pt(NH(3))(2)Cl(2), is a cancer drug believed to kill cells via DNA binding and damage. Recent work has implied that the cellular copper (Cu) transport machinery may be involved in cisPt cell export and drug resistance. Normally, the Cu chaperone Atox1 binds Cu(I) via two cysteines and delivers the metal to metal-binding domains of ATP7B; the ATP7B domains then transfer the metal to the Golgi lumen for loading on cuproenzymes. Here, we use spectroscopic methods to test if cisPt interacts with purified Atox1 in solution in vitro. We find that cisPt binds to Atox1's metal-binding site regardless of the presence of Cu or not: When Cu is bound to Atox1, the near-UV circular dichroism signals indicate Cu-Pt interactions. From NMR data, it is evident that cisPt binds to the folded protein. CisPt-bound Atox1 is however not stable over time and the protein begins to unfold and aggregate. The reaction rates are limited by slow cisPt dechlorination. CisPt-induced unfolding of Atox1 is specific because this effect was not observed for two unrelated proteins that also bind cisPt. Our study demonstrates that Atox1 is a candidate for cisPt drug resistance: By binding to Atox1 in the cytoplasm, cisPt transport to DNA may be blocked. In agreement with this model, cell line studies demonstrate a correlation between Atox1 expression levels, and cisplatin resistance.
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| 2. |
- Ramazani, Mari, 1963-, et al.
(författare)
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Increased circulating levels of basement-membrane components in patients with abdominal aortic aneurysms : A Pilot Study
- 2011
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Ingår i: European Journal of Vascular and Endovascular Surgery. - London : Grune & Stratton. - 1078-5884 .- 1532-2165. ; 42:4, s. 484-487
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Tidskriftsartikel (refereegranskat)abstract
- Aim: The decision for abdominal aortic aneurysm (AM) repair is based on aneurysm size. However, smaller aneurysms can rupture, while larger ones can remain stable. New variables and markers are needed to better select patients at high rupture risk. The study was done to analyse if AAA patients have increased levels of circulating basement-membrane (BM) fragments.Design: Circulating levels of BM components type IV and XVIII collagen were measured by enzyme-linked immunosorbent assay (ELISA) in 10 patients with AAA, nine patients with peripheral artery disease (PAD) and 10 healthy controls (CON).Results: AAA patients had significantly increased levels of type IV and XVIII collagen compared with CON (134.0 +/- 24.8 ng ml(-1) vs. 104.5 +/- 16.4 ng ml(-1); p = 0.005 and 149.0 +/- 56.9 ng ml(-1) vs. 59.6 +/- 8.7 ng ml(-1); p < 0.001, respectively). The PAD patients did not have significantly increased levels of these fragments when compared with CON. In addition, the AAA patients had significantly increased level of type XVIII collagen (149.0 +/- 56.9 ng ml(-1) vs. 58.3 +/- 25.4 ng/ml(-1); p < 0.01) when compared with the PAD group.Conclusion: Based on this preliminary analysis of a small number of subjects, patients with AAA had significantly increased levels of circulating BM components. BM fragments should be studied further to establish their potential role as biomarkers for AAA.
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| 3. |
- Öhlund, Daniel, 1979-, et al.
(författare)
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Type IV collagen stimulates pancreatic cancer cell proliferation, migration, and inhibits apoptosis through an autocrine loop
- 2013
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Ingår i: BMC Cancer. - : Springer Science and Business Media LLC. - 1471-2407. ; 13
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Tidskriftsartikel (refereegranskat)abstract
- Background: Pancreatic cancer shows a highly aggressive and infiltrative growth pattern and is characterized by an abundant tumor stroma known to interact with the cancer cells, and to influence tumor growth and drug resistance. Cancer cells actively take part in the production of extracellular matrix proteins, which then become deposited into the tumor stroma. Type IV collagen, an important component of the basement membrane, is highly expressed by pancreatic cancer cells both in vivo and in vitro. In this study, the cellular effects of type IV collagen produced by the cancer cells were characterized.Methods: The expression of type IV collagen and its integrin receptors were examined in vivo in human pancreatic cancer tissue. The cellular effects of type IV collagen were studied in pancreatic cancer cell lines by reducing type IV collagen expression through RNA interference and by functional receptor blocking of integrins and their binding-sites on the type IV collagen molecule.Results: We show that type IV collagen is expressed close to the cancer cells in vivo, forming basement membrane like structures on the cancer cell surface that colocalize with the integrin receptors. Furthermore, the interaction between type IV collagen produced by the cancer cell, and integrins on the surface of the cancer cells, are important for continuous cancer cell growth, maintenance of a migratory phenotype, and for avoiding apoptosis.Conclusion: We show that type IV collagen provides essential cell survival signals to the pancreatic cancer cells through an autocrine loop.
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