Related Experiment Video
Updated: Jun 12, 2026
Through the Looking Glass: Time-lapse Microscopy and Longitudinal Tracking of Single Cells to Study Anti-cancer Therapeutics
Published on: May 14, 2016
Beryllium sulfate induces p21 CDKN1A expression and a senescence-like cell cycle arrest in susceptible cancer cell
Priyatham Gorjala1, Ronald K Gary
1Department of Chemistry, University of Nevada Las Vegas, 4505 Maryland Parkway, Las Vegas, NV 89154-4003, USA.
Abstract:
In fibroblasts, beryllium salt causes activation of the p53 transcription factor and induction of a senescence-like state. It is not known whether Be(2+) can affect the proliferation of cancer cells, which are generally unsusceptible to senescence. A172 glioblastoma and RKO colon carcinoma cell lines each have wildtype p53, so these cell types have the potential to be responsive to agents that activate p53. In A172 cells, BeSO(4) produced a G(0)/G(1)-phase cell cycle arrest and increased expression of senescence-associated β-galactosidase, an enzymatic marker of senescence. BeSO(4) caused phosphorylation of serine-15 of p53, accumulation of p53 protein, and expression of p21, the cyclin-dependent kinase inhibitor that is prominent during senescence. BeSO(4) inhibited A172 growth with an IC(50) = 4.7 microM in a 6-day proliferation assay. In contrast, BeSO(4) had no effect on RKO cells, even though Be(2+) uptake was similar for the two cell types. This differential responsiveness marks BeSO(4) as a reagent capable of activating a separable branch of the p53 signaling network. A172 and RKO cells are known to exhibit p53-dependent upregulation of p21 in response to DNA damage. The RKO cells produced high levels of p21 when exposed to DNA damaging agents, yet failed to express p21 when treated with BeSO(4). Conversely, BeSO(4) did not cause DNA damage in A172 cells, yet it was a potent inducer of p21 expression. These observations indicate that the growth control pathway affected by BeSO(4) is distinct from the DNA damage response pathway, even though both ultimately converge on p53 and p21.
Insights
Beryllium sulfate (BeSO4) halts glioblastoma cell growth by activating p53 and inducing senescence, but does not affect colon cancer cells. This suggests BeSO4 targets a distinct p53 pathway separate from DNA damage response.
Area of Science:
- Cell Biology
- Cancer Research
- Toxicology
Background:
- Beryllium salts activate p53 and induce senescence in fibroblasts.
- Cancer cells are often resistant to senescence induction.
- The effect of beryllium on cancer cell proliferation and p53 signaling is largely unknown.
Purpose of the Study:
- To investigate the effect of beryllium sulfate (BeSO4) on the proliferation and p53 signaling pathway in A172 glioblastoma and RKO colon carcinoma cell lines.
- To determine if BeSO4 can induce senescence in cancer cells.
- To elucidate the distinct p53-dependent pathways affected by BeSO4 compared to DNA damage.
Main Methods:
- Cell culture of A172 glioblastoma and RKO colon carcinoma lines.
- Treatment with beryllium sulfate (BeSO4).
- Assays for cell cycle arrest, senescence-associated β-galactosidase activity, p53 protein levels, p21 expression, and cell proliferation (IC50 determination).
- Analysis of beryllium uptake and response to DNA damaging agents.
Main Results:
- BeSO4 induced G0/G1 cell cycle arrest, senescence markers, p53 activation, and p21 expression in A172 cells.
- BeSO4 inhibited A172 cell proliferation with an IC50 of 4.7 μM.
- BeSO4 had no effect on RKO cells despite similar beryllium uptake.
- BeSO4 induced p21 in A172 cells independently of DNA damage, unlike the DNA damage response pathway.
Conclusions:
- BeSO4 selectively inhibits glioblastoma cell growth by activating a senescence pathway via p53.
- The mechanism of BeSO4-induced p53 activation and p21 expression is distinct from the DNA damage response pathway.
- Differential responsiveness of cancer cell lines to BeSO4 highlights its potential as a tool to probe specific p53 signaling branches.
Related Concept Videos
02:34Inhibition of Cdk Activity
02:34Inhibition of CDK Activity
01:23Negative Regulator Molecules
02:36DNA Damage can Stall the Cell Cycle
02:36DNA Damage Can Stall the Cell Cycle
02:15Replicative Cell Senescence