Related Experiment Videos
Vanadate-induced cell growth arrest is p53-dependent through activation of p21 in C141 cells
Zhuo Zhang1, Chuanshu Huang, Jinxia Li
1Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV 26505, USA.
Abstract:
Vanadium is widely used in industry. It is a potent toxic agent and carcinogen. The mechanisms involved in its toxicity and carcinogenesis are still unclear. Improper cell growth is believed to be involved in cancer development. The present study investigated the regulation of p53 on vanadate-induced cell growth arrest using both p53 wild type C141 cells and p53 deficient embryo fibroblasts (p53 -/-). On vanadate stimulation, C141 cells exhibited a dose- and time-dependent S phase arrest as determined by DNA content analysis. In contrast, vanadate was unable to increase the percentage of S phase in p53 -/- cells. Luciferase assay showed that vanadate induced p53 activation in a dose- and time-dependent manner in p53 wild type C141 cells. Addition of pifithrin-alpha (PFT), a specific inhibitor of p53, reduced the activation of p53 with a concomitant decrease in growth arrest at S phase. Western blotting analysis demonstrated that vanadate caused a dose- and time-dependent increase of p21 level in C141 cells. Pretreatment of C141 cells with PFT decreased p21 expression induced by vanadate while the p21 expression did not vary in vanadate stimulated p53 -/- cells. The results obtained from the present study suggest that vanadate is able to induce S phase arrest through p53- and p21-dependent pathway.
Insights
Vanadate exposure causes cell cycle arrest at the S phase through a pathway involving p53 and p21. This mechanism is crucial for understanding vanadium
Area of Science:
- Toxicology
- Cell Biology
- Carcinogenesis
Background:
- Vanadium compounds, widely used industrially, are recognized as toxic and carcinogenic agents.
- The precise mechanisms underlying vanadium toxicity and its role in cancer development remain incompletely understood.
- Disruptions in normal cell growth regulation are implicated in the initiation and progression of cancer.
Purpose of the Study:
- To investigate the role of the p53 tumor suppressor protein in mediating vanadate-induced cell cycle arrest.
- To elucidate the involvement of the p53-p21 pathway in the cellular response to vanadate exposure.
Main Methods:
- Utilized p53 wild-type (C141) and p53-deficient (p53 -/-) mouse embryo fibroblasts.
- Assessed cell cycle progression via DNA content analysis following vanadate treatment.
- Quantified p53 activation using luciferase reporter assays.
- Examined the expression levels of p21 protein via Western blotting.
- Investigated the effect of pifithrin-alpha (PFT), a p53 inhibitor, on vanadate-induced responses.
Main Results:
- Vanadate induced a dose- and time-dependent S phase arrest in p53 wild-type cells, but not in p53-deficient cells.
- Vanadate treatment led to a dose- and time-dependent activation of p53 in wild-type cells.
- Inhibition of p53 by PFT attenuated vanadate-induced S phase arrest and p53 activation.
- Vanadate exposure increased p21 protein levels in a dose- and time-dependent manner in wild-type cells.
- Pifithrin-alpha pretreatment reduced vanadate-induced p21 expression, while p21 levels remained unchanged in vanadate-treated p53-deficient cells.
Conclusions:
- Vanadate induces S phase cell cycle arrest through a mechanism dependent on p53 activation.
- The p53-regulated protein p21 plays a critical role in mediating vanadate-induced cell growth arrest.
- These findings highlight a key molecular pathway involved in vanadium-induced cellular toxicity and potential carcinogenicity.