The Interaction between Dietary Selenium Intake and Genetics in Determining Cancer Risk and Outcome.

Shrinidhi Kadkol,Alan M Diamond

doi:10.3390/nu12082424

Abstract

There is considerable interest in the trace element selenium as a possible cancer chemopreventive dietary component, but supplementation trials have not indicated a clear benefit. Selenium is a critical component of selenium-containing proteins, or selenoproteins. Members of this protein family contain selenium in the form of selenocysteine. Selenocysteine is encoded by an in-frame UGA codon recognized as a selenocysteine codon by a regulatory element, the selenocysteine insertion sequence (SECIS), in the 3′-untranslated region of selenoprotein mRNAs. Epidemiological studies have implicated several selenoprotein genes in cancer risk or outcome based on associations between allelic variations and disease risk or mortality. These polymorphisms can be found in or near the SECIS or in the selenoprotein coding sequence. These variations both function to control protein synthesis and impact the efficiency of protein synthesis in response to the levels of available selenium. Thus, an individual’s genetic makeup and nutritional intake of selenium may interact to predispose them to acquiring cancer or affect cancer progression to lethality.

Highlights

Reports emerging in the 1970s indicated an inverse association between the dietary availability of the essential nutrient selenium and cancer incidence, sparking interest in using selenium for chemoprevention
Selenium supplementation did not protect from skin cancer recurrence, but secondary analyses indicated that the selenium-supplemented group had a lower incidence of common cancers, including those of colon, lung, and prostate [4]
Using two different specialized reporter constructs, we have shown that these genetic variations are functional and likely contribute to determining the amount of Selenoprotein F (SELENOF) protein made as a function of selenium availability [75,80]

Summary

Introduction

Reports emerging in the 1970s indicated an inverse association between the dietary availability of the essential nutrient selenium and cancer incidence, sparking interest in using selenium for chemoprevention. States previously determined to have an elevated risk for disease recurrence [3] In this trial, selenium supplementation did not protect from skin cancer recurrence, but secondary analyses indicated that the selenium-supplemented group had a lower incidence of common cancers, including those of colon, lung, and prostate [4]. Selenium supplementation did not protect from skin cancer recurrence, but secondary analyses indicated that the selenium-supplemented group had a lower incidence of common cancers, including those of colon, lung, and prostate [4] These results were not the primary endpoints of the study and there were relatively few cancers of these types among the participants, but the findings were considered encouraging enough to initiate other selenium supplementation trials. The term selenoproteins will be used to refer only to proteins containing selenocysteine

30 UTR—SECIS

Selenoproteins and Their Regulation by Selenium Levels

Selenium and Glutathione Peroxidase 1 Allelic Interactions

Findings

Conclusions