Selenium and selenoprotein deficiencies induce widespread pyogranuloma formation in mice, while high levels of...

Area of Science:

• Biochemistry
• Toxicology
• Oncology

Background:

• Dietary selenium and selenoprotein levels influence anti- and pro-cancer pathways.
• Intervention outcomes vary due to these complex interactions.
• Understanding these effects requires controlled studies isolating dietary and selenoprotein status.

Purpose of the Study:

• To investigate the effects of varying dietary selenium levels and altered selenoprotein status on hepatocarcinogenesis.
• To differentiate the impact of diet versus selenoprotein status using transgenic mice.
• To characterize the resulting phenotypes, including inflammation and tumor development.

Main Methods:

• Utilized mice with mutant selenocysteine tRNA (Trsp(tG37)) and/or TGFα transgenes.
• Administered diets with varying selenium concentrations (0.02-2.25 ppm) or triphenylselenonium chloride (TPSC).
• Performed pathological analyses to assess inflammation and liver tumor development.

Main Results:

• Selenium deficiency and TPSC diet induced neurological issues and pyogranulomatous inflammation in transgenic mice.
• TGFα transgene increased liver tumor incidence.
• Higher selenium levels (0.4 and 2.25 ppm) reduced the size of TGFα-induced liver tumors, but not their number.

Conclusions:

• Selenium and selenoprotein deficiencies can lead to systemic pyogranuloma formation.
• Adequate dietary selenium inhibits the growth of TGFα-induced liver tumors.
• Findings highlight the dual role of selenium in inflammation and cancer progression.