Cadmium at a non-toxic dose alters gene expression in mouse testes

• Published in: Toxicology letters Vol. 154; no. 3; pp. 191 - 200
• Main Authors: Zhou, Tong, Jia, Xiaodong, Chapin, Robert E., Maronpot, Robert R., Harris, Martha W., Liu, Jie, Waalkes, Michael P., Eddy, Edward M.
• Format: Journal Article
• Language: English
• Published: Shannon Elsevier Ireland Ltd 30.12.2004; Amsterdam Elsevier Science
• Subjects: Animals; Apoptosis - drug effects; Biological and medical sciences; Cadmium; Cadmium - pharmacokinetics; Cadmium - toxicity; Cell Cycle - drug effects; Cell Proliferation - drug effects; Chemical and industrial products toxicology. Toxic occupational diseases; DNA Damage - drug effects; DNA Repair - drug effects; Gene Expression Profiling; Gene Expression Regulation - drug effects; Male; Medical sciences; Metals and various inorganic compounds; Mice; Microarray; Mouse; Oligonucleotide Array Sequence Analysis; Real-time RT-PCR; Testes; Testis - drug effects; Testis - metabolism; Testis - pathology; Toxicology; Real-time RT-PCR; Cadmium; Mouse; Microarray; Testes; RNA-directed DNA polymerase; Enzyme; Toxicity; Transferases; Rodentia; DNA chip; Gene expression; Real time; Testicle; Male genital system; Heavy metal; Nucleotidyltransferases; Vertebrata; Mammalia; Animal; Dose; Reverse transcription polymerase chain reaction
• ISSN: 0378-4274; 1879-3169
• DOI: 10.1016/j.toxlet.2004.07.015

The testes are important targets of cadmium (Cd)-induced toxicity and carcinogenicity in rodents. Exposure to Cd at environmentally relevant low levels is a significant human health concern, but the effects of Cd on the rodent testes at doses that do not cause overt lesions are poorly defined. We used cDNA microarray and quantitative real-time RT-PCR assays to determine gene expression profiles in the testes of CD-1 mice 12–72 h after a single s.c. injection of 5 μmol/kg CdCl 2. This dose of Cd did not produce overt histopathological changes, but clearly altered the expression of some genes that are likely to be important in toxicity responses. The most significant changes in gene expression occurred 24 h after treatment, corresponding to when the highest level of Cd was detected in the testes. Increased expression of the C- myc and Egr1 genes strongly suggests acute stress responses. Repressed expression of cell cycle-regulated cyclin B1 and CDC2 proteins indicates a potential for causing G2/M arrest and disturbance of meiosis. Decreased expression of pro-apoptotic genes, particularly Casp3, and DNA repair genes possibly contributes to Cd-induced carcinogenesis. These results indicate that changes in gene expression occur well before overt effects of Cd-induced testicular toxicity and carcinogenicity are apparent.