New model for evaluation of endocrine disruption of steroidogenesis in H295R cell line
| Authors | |
|---|---|
| Year of publication | 2005 |
| Type | Article in Proceedings |
| Conference | ECOTOX 2005 |
| MU Faculty or unit | |
| Citation | |
| Field | Environment influence on health |
| Keywords | steroidogenesis H295R disruption |
| Description | One of the most hazardous properties of xenobiotics is their ability to interact with endocrine system of the organisms leading to number of negative consequences. After discovery of endocrine disrupting potential of wide range of environmental pollutants, the main concern was devoted to study of mechanism of interaction between xenobiotic compounds and steroid hormone receptors (particularly interaction with estrogenic receptor). Less attention was focused on other parts of this signaling pathway, such as steroidogenesis, which is involved in steroid signaling pathway that regulates many crucial physiologic processes such as carcinogenesis, immunotoxicity or reduced fecundity. We have developed a model for assessment of the potency of various chemicals or their mixtures (pharmaceuticals, environmental contaminants, pesticides...) to affect levels of produced steroids. The model is based on a human carcinoma cell line H295R, which retains the ability to synthesize most of the important steroidogenic enzymes. The cells were cultivated in a medium with charcoal-dextrane treated serum. After 24-hour exposure to the tested chemicals and forskolin the levels of steroids were measured directly in cultivation medium using ELISA kits. The results were normalized to total protein content. We studied endocrine disrupting effects of several xenobiotics (e.g. POPs: TCDD, B(a)P; pesticides: vinclozolin; pharmaceuticals: metyrapone, spironolactone) on production of number of steroid hormones (such as testosterone, 17b-estradiol, androstenedione, 17-OH-progesterone, cortisol). Obtained results show that the effects of the chemicals are compound-specific and that the chemicals can interact with multiple levels of steroidogenesis. For example, incubation of cells with TCDD shows dose dependent increase in production of testosterone and 17b-estradiol while production of androstenedione and 17-OH-progesterone stays unchanged. The model used does not allow detailed mechanistic studies of the effects of chemicals on steroidogenesis at molecular level (like real time PCR or enzyme activity studies). On the other hand, it shows the final effects on the level of production of hormones that is more toxicologically relevant than outputs from methods mentioned above. The assay is suitable for evaluating of endocrine disrupting effects of chemicals and for screening purposes thanks to its relatively simplicity and low costs. |
| Related projects: |