Human Lung Cancer Cell Line A-549 ATCC Is Differentially Affected by Supranutritional Organic and Inorganic Selenium

Abstract

The effects of organic and inorganic forms of selenium (Se) on human cells have been extensively studied for nutritional concentrations; however, to date, little is known about the potential toxicity at supranutritional levels. In the present study we determined the effects of sodium selenite (SSe) and selenomethionine (SeMet) on cell growth and intracellular structures in lung cancer cells exposed at Se concentrations between 0 and 3 mM. Our results showed that SSe affected cell growth more rapidly than SeMet (24 h and 48 h, resp.). After 24 h of cells exposure to 0.5, 1.5, and 3 mM SSe, cell growth was reduced by 10, 50, and 60%, as compared to controls. After 48 h, nuclear fragmentation was evident in cells exposed to SSe, suggesting an induction to cell death. In contrast, SeMet did not affect cell proliferation, and the cells were phenotypically similar to controls. Microtubules and microfilaments structures were also affected by both Se compounds, again SSe being more toxic than SeMet. To our knowledge, this is the first report on the differential effects of organic and inorganic Se in supranutritional levels in lung cancer cells.

Side‐Directed Transfer and Presystemic Metabolism of Selenoneine in a Human Intestinal Barrier Model

“…Here, exposure of the cells for 6 h with selenite concentrations higher than 100 µ m significantly reduced cell viability, while MeSeCys was non‐toxic . In agreement with other in vitro and rodent studies, selenite displayed considerably higher cytotoxicity compared to organic Se species . However, Caco‐2 cells were less sensitive compared to proliferating liver (HepG2), urothelial (UROtsa), and astrocytoma (CCF‐STTG‐1) cells, which is most likely due to the cells’ differentiation status.…”

Selenium species-dependent toxicity, bioavailability and metabolic transformations inCaenorhabditis elegans

“…These data are in agreement with studies in other model systems in literature, corroborating greater toxicity of inorganic selenite compared to organic Se species. 9,11,14,31 Studies in C. elegans on the toxicity of Se compounds are scarce. While a few studies have addressed the toxicity of selenite, SeMet and MeSeCys have yet to be investigated.…”

“…While many studies in human in vitro models are available (e.g. 9–14 ), in vivo studies on the species-dependent toxicity and bioavailability are scarce. Being less complex than mammalian systems, the tractable invertebrate Caenorhabditis elegans ( C. elegans ) is a complementary and alternative in vivo model system in toxicological research and a multipurpose tool to study the effect of trace elements and macromolecules in the context of a whole organism.…”

Differing cytotoxicity and bioavailability of selenite, methylselenocysteine, selenomethionine, selenosugar 1 and trimethylselenonium ion and their underlying metabolic transformations in human cells

“…Selenite was by far the most toxic substance in all tested cell lines with IC 50 values in the low M concentration range (see Table 3). As a frequently used reference substance and a common constituent of Se supplements, selenite has already been examined in various in vivo and in vitro studies, resulting in more pronounced cytotoxic effects as compared to organic Se species [20,36,37]. Hoefig et al determined for HepG2 cells after 48 h of incubation using the MTT test an IC 50 value of 5.5 M, which is close to the value determined here by cell number (IC 50 7.6 M) [38].…”