A controversy over whether selenium can fight cancer in humans might come down to which form of the essential micronutrient people take, scientists are reporting. It turns out that not all “seleniums” are the same — the researchers found that one type of selenium supplement may produce a possible cancer-preventing substance more efficiently than another form of selenium in human cancer cells. Their study appears in the ACS’ journal Biochemistry.
Hugh Harris and colleagues note that although the Nutritional Prevention of Cancer clinical trial showed that selenium reduced the risk of cancer, a later study called the Selenium and Vitamin E Cancer Prevention Trial did not show a benefit. A major difference between the trials was the form of selenium that was used. To find out whether different types of selenium have different chemopreventive properties, the researchers studied how two forms — SeMet and MeSeCys — are processed in human lung cancer cells.The new study
The researchers found that MeSeCys killed more lung cancer cells than SeMet did. Also, lung cancer cells treated with MeSeCys processed the selenium differently than than cells treated with SeMet. They say that these findings could explain why studies on the health benefits of selenium sometimes have conflicting results.
The authors acknowledge funding from the Australian Research Council.
Source: American Chemical Society The original study
Claire M. Weekley, Jade B. Aitken, Stefan Vogt, Lydia A. Finney, David J. Paterson, Martin D. de Jonge, Daryl L. Howard, Ian F. Musgrave, Hugh H. Harris, Uptake, Distribution, and Speciation of Selenoamino Acids by Human Cancer Cells: X-ray Absorption and Fluorescence Methods
, Biochemistry, 50/10 (2011) 1641–1650. DOI: 10.1021/bi101678a Related Studies
Hitoshi Ueno, Gohki Hasegawa, Ryoko Ido, Tomofumi Okuno, Katsuhiko Nakamuro, Effects of selenium status and supplementary seleno-chemical sources on mouse T-cell mitogenesis,
J. Trace Elem. Med. Biol., 22 (2008) 9–16. doi: 10.1016/j.jtemb.2007.10.002
S.M. Lippman, E.A. Klein, P.J. Goodman, M.S. Lucia, I.M. Thompson, L.G. Ford, H.L. Parnes, L.M. Minasian, J.M. Gaziano, J.A. Hartline, J.K. Parsons, J.D. Bearden, E.D. Crawford, G.E. Goodman, J. Claudio, E. Winquist, E.D. Cook, D.D. Karp, P. Walther, M.M. Lieber, A.R. Kristal, A.K. Darke, K.B. Arnold, P.A. Ganz, R.M. Santella, D. Albanes, P.R. Taylor, J.L. Probstfield, T.J. Jagpal, J.J. Crowley, F.L. Meyskens, L.H. Baker, C.A. Coltman, Effect of selenium and vitamin E on risk of prostate cancer and other cancers: The Selenium and Vitamin E Cancer Prevention Trial (SELECT)
, J. Am. Med. Assoc., 301 (2009) 39– 51. doi: 10.1001/jama.2008.864
B. Gammelgaard, C. Gabel-Jensen, S. Stürup, H.R. Hansen, Complementary use of molecular and element-specific mass spectrometry for identification of selenium compounds related to human selenium metabolism,
Anal. Bioanal. Chem., 390 (2008) 1691– 1706. doi: 10.1007/s00216-007-1788-8
E.N. Drake, Cancer chemoprevention: Selenium as a prooxidant, not an antioxidant
, Medical Hypotheses, 67/2 (2006) 318-322. doi:10.1016/j.mehy.2006.01.058
E.H. Larsen, M. Hansen, H. Paulin, S. Moesgaard, M. Reid, M. Rayman, Speciation and bioavailability of selenium in yeast-based intervention agents used in cancer chemoprevention studies
, J. AOAC Int., 87 (2004) 225– 232. doi: 10.5555/jaoi,2004.87.1.225
M. Soriano-Garcia, Organoselenium compounds as potential therapeutic and chemopreventive agents: A review
, Curr. Med. Chem., 11 (2004) 57– 1669.
A.J. Duffield-Lillico, B.L. Dalkin, M.E. Reid, B.W. Turnbull, E.H. Slate, E.T. Jacobs, J.R. Marshall, L.C. Clark, Selenium supplementation, baseline plasma selenium status and incidence of prostate cancer: An analysis of the complete treatment period of the Nutritional Prevention of Cancer Trial,
BJU Int., 91 (2003) 608– 612. doi: 10.1046/j.1464-410X.2003.04167.x
H.E. Ganther, J.R. Lawrence, Chemical transformations of selenium in living organisms. Improved forms of selenium for cancer prevention
, Tetrahedron, 53 (1997) 12299– 12310. doi:10.1016/S0040-4020(97)00561-9
L.C. Clark, G.F. Combs, B.W. Turnbull, E.H. Slate, D.K. Chalker Chalker, J. Chow, L.S. Davis, R.A. Glover, G.F. Graham, E.G. Gross, A. Krongrad, J.L. Lesher, H.K. Park, B.B. Sanders, C.L. Smith, J.R. Taylor, Effects of selenium supplementation for cancer prevention in patients with carcinoma of the skin. A randomized controlled trial. Nutritional Prevention of Cancer Study Group JAMA
, J. Am. Med. Assoc., 276 (1996) 1957– 1963.
C. Ip, C. Hayes, R.M. Budnick, H.E. Ganther, Chemical form of selenium, critical metabolites, and cancer prevention
, Cancer Res., 51 (1991) 595– 600. http://cancerres.aacrjournals.org/content/51/2/595.long
C. Ip, H.E. Ganther, Activity of methylated forms of selenium in cancer prevention
, Cancer Res., 50 (1990) 1206– 1211. http://cancerres.aacrjournals.org/content/50/4/1206.long Related EVISA News May 12, 2011: Review: Selenium doesn't prevent cancer May 3, 2011: New reference materials for the characterisation of selenium-enriched food products June 19, 2010: A
new Selenium-containing compound, Selenoneine, found as the predominant
Se-species in the blood of Bluefin Tuna July 20, 2009: Researchers Reveal Selenium's Metabolism In Life-Giving Amino Acids October 28, 2008: National Cancer Institute ends Selenium and Vitamin E Cancer
Prevention Trial, or SELECT March 16, 2008: New selenium-containing proteins identified in selenium-rich yeast October 16, 2005: New light on human selenium metabolism October 6, 2005: Selenomethionine shows promising results as a protective agent
against Esophageal Cancer March 8, 2005: Selenoprotein P is required for normal sperm development
last time modified: May 22, 2011