Limits...
Induction of p53-inducible microRNA miR-34 by gamma radiation and bleomycin are different.

Mert U, Ozgür E, Tiryakioglu D, Dalay N, Gezer U - Front Genet (2012)

Bottom Line: The basal level of p53 in MCF-7 cells was higher (approx. 6-fold) than in HeLa cells, and its accumulation was similar for both DNA-damaging agents in both cell lines.BLM did not significantly affect miR-34 expression in both cell types.In conclusion, our findings reveal that miR-34 induction by genotoxic stress may be cell-type specific.

View Article: PubMed Central - PubMed

Affiliation: Department of Basic Oncology, Oncology Institute, Istanbul University Istanbul, Turkey.

ABSTRACT
microRNAs (miRNAs) are small molecules in their mature form and master regulators of gene expression. Recent work has shown that miRNAs are involved in the p53 network. Of the various miRNAs, miR-34 is regulated by the p53 protein. miR-34 can be induced by ionizing radiation (IR) in vitro and in vivo. However, there is no data in the literature for induction of miR-34 by a chemical agent inducing DNA damage. Here we studied the expression of miR-34 in HeLa and MCF-7 cells exposed to genotoxic stress-induced by bleomycin (BLM) or γ-radiation. We first analyzed p53 accumulation upon DNA damage induction. The basal level of p53 in MCF-7 cells was higher (approx. 6-fold) than in HeLa cells, and its accumulation was similar for both DNA-damaging agents in both cell lines. We have shown that miR-34 is significantly induced by γ-radiation in HeLa cells, but not in MCF-7 cells. BLM did not significantly affect miR-34 expression in both cell types. In conclusion, our findings reveal that miR-34 induction by genotoxic stress may be cell-type specific.

No MeSH data available.


Related in: MedlinePlus

Accumulation of p53 protein. Cytoplasmic lysates of BLM-treated and irradiated cells were used to quantitatively determine the accumulation of p53 protein (A and B) by ELISA. Results of three-independent cell culture experiments were evaluated to calculate the average value. BLM, bleomycin; Rad., radiation.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC3475997&req=5

Figure 1: Accumulation of p53 protein. Cytoplasmic lysates of BLM-treated and irradiated cells were used to quantitatively determine the accumulation of p53 protein (A and B) by ELISA. Results of three-independent cell culture experiments were evaluated to calculate the average value. BLM, bleomycin; Rad., radiation.

Mentions: p53 protein levels were measured 24 h after adding BLM to the medium or irradiation of the cells. The basal p53 expression level in the MCF-7 cells was higher (approx. 6-fold) than the in HeLa cells. As seen in Figure 1, a similar p53 accumulation pattern was observed in response to both DNA-damaging treatments in both cell lines. BLM treatment with doses of 37.5 and 75 μg/mL led to an 1.92 and 2.56-fold increase in the amount of p53 in HeLa cells, respectively, when compared to untreated cells (Figure 1A). For irradiation, the rates were 3 and 3.3-fold for doses of 2 and 5 Gy, respectively. In the MCF-7 cells (Figure 1B), the increase in the p53 levels was slightly higher (2.98 and 3.6-fold) for the indicated BLM doses when compared to radiation (3.28 and 4.46-fold).


Induction of p53-inducible microRNA miR-34 by gamma radiation and bleomycin are different.

Mert U, Ozgür E, Tiryakioglu D, Dalay N, Gezer U - Front Genet (2012)

Accumulation of p53 protein. Cytoplasmic lysates of BLM-treated and irradiated cells were used to quantitatively determine the accumulation of p53 protein (A and B) by ELISA. Results of three-independent cell culture experiments were evaluated to calculate the average value. BLM, bleomycin; Rad., radiation.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3475997&req=5

Figure 1: Accumulation of p53 protein. Cytoplasmic lysates of BLM-treated and irradiated cells were used to quantitatively determine the accumulation of p53 protein (A and B) by ELISA. Results of three-independent cell culture experiments were evaluated to calculate the average value. BLM, bleomycin; Rad., radiation.
Mentions: p53 protein levels were measured 24 h after adding BLM to the medium or irradiation of the cells. The basal p53 expression level in the MCF-7 cells was higher (approx. 6-fold) than the in HeLa cells. As seen in Figure 1, a similar p53 accumulation pattern was observed in response to both DNA-damaging treatments in both cell lines. BLM treatment with doses of 37.5 and 75 μg/mL led to an 1.92 and 2.56-fold increase in the amount of p53 in HeLa cells, respectively, when compared to untreated cells (Figure 1A). For irradiation, the rates were 3 and 3.3-fold for doses of 2 and 5 Gy, respectively. In the MCF-7 cells (Figure 1B), the increase in the p53 levels was slightly higher (2.98 and 3.6-fold) for the indicated BLM doses when compared to radiation (3.28 and 4.46-fold).

Bottom Line: The basal level of p53 in MCF-7 cells was higher (approx. 6-fold) than in HeLa cells, and its accumulation was similar for both DNA-damaging agents in both cell lines.BLM did not significantly affect miR-34 expression in both cell types.In conclusion, our findings reveal that miR-34 induction by genotoxic stress may be cell-type specific.

View Article: PubMed Central - PubMed

Affiliation: Department of Basic Oncology, Oncology Institute, Istanbul University Istanbul, Turkey.

ABSTRACT
microRNAs (miRNAs) are small molecules in their mature form and master regulators of gene expression. Recent work has shown that miRNAs are involved in the p53 network. Of the various miRNAs, miR-34 is regulated by the p53 protein. miR-34 can be induced by ionizing radiation (IR) in vitro and in vivo. However, there is no data in the literature for induction of miR-34 by a chemical agent inducing DNA damage. Here we studied the expression of miR-34 in HeLa and MCF-7 cells exposed to genotoxic stress-induced by bleomycin (BLM) or γ-radiation. We first analyzed p53 accumulation upon DNA damage induction. The basal level of p53 in MCF-7 cells was higher (approx. 6-fold) than in HeLa cells, and its accumulation was similar for both DNA-damaging agents in both cell lines. We have shown that miR-34 is significantly induced by γ-radiation in HeLa cells, but not in MCF-7 cells. BLM did not significantly affect miR-34 expression in both cell types. In conclusion, our findings reveal that miR-34 induction by genotoxic stress may be cell-type specific.

No MeSH data available.


Related in: MedlinePlus