Transforming and carcinogenic potential of cadmium chloride in BALB/c-3T3 cells.
Keshava N; Zhou G; Hubbs AF; Ensell MX; Ong T
Mutat Res 2000 Mar; 448(1):23-28
A large number of workers are potentially exposed to cadmium during mining and processing. Therefore, there is a concern regarding the potential carcinogenic hazards of cadmium to exposed workers. Studies have been performed to determine if cadmium chloride (CdCl(2)) can induce morphological cell transformation, DNA from CdCl(2)-induced transformed cells can transform other mammalian cells, and the transformed cells induced by CdCl(2) can form tumors in nude mice. BALB/c-3T3 cells were treated with different concentrations of CdCl(2) for 72 h. The frequency of transformed foci from each treatment was determined after cells were cultured for 4 to 5 weeks. DNAs from five CdCl(2)-induced transformed cell lines were isolated and gene transfection assay was performed using NIH-3T3 cells. Non-transformed BALB/c-3T3 cells and cells from 10 transformed cell lines induced by CdCl(2) were injected into both axillary regions of nude mice. Mice were screened once a week for the appearance and size of tumors. CdCl(2) caused a statistically significant, concentration-related increase in the transformation frequency. DNA from all five CdCl(2)-induced transformed cell lines tested was found to induce varying degrees of transfection-mediated transformation in NIH-3T3 cells. All 10 CdCl(2)-induced transformed cell lines formed fibrosarcomas in nude mice within 39 days of inoculation. Within this time period, no tumors were found in nude mice injected with non-transformed BALB/c-3T3 cells. These results indicate that CdCl(2) is capable of inducing morphological cell transformation and that the transformed cells induced by CdCl(2) are potentially tumorigenic.
Carcinogens; Carcinogenicity; Carcinogenesis; Cadmium compounds; Occupational exposure; Worker health; Work environment; Mining industry; Mine workers; Cell transformation; Morphology; Tumors; Laboratory animals; Animals; Animal studies;
Author Keywords: Cell transformation; Gene transfection; Tumorigenicity; Cadmium chloride; BALB/c-3T3 cells
Toxicology and Molecular Biology Branch, Health Effects Laboratory Division, National Institute for Occupational Safety and Health, m/s 3014, 1095 Willowdale Road, Morgantown, WV 26505-2845, USA