Limits...
Cathepsin L suppression increases the radiosensitivity of human glioma U251 cells via G2/M cell cycle arrest and DNA damage.

Zhang QQ, Wang WJ, Li J, Yang N, Chen G, Wang Z, Liang ZQ - Acta Pharmacol. Sin. (2015)

Bottom Line: Irradiation significantly increased the cytoplasmic and nuclear levels of cathepsin L in U251 cells but not in U87 cells.Treatment with the specific cathepsin L inhibitor Z-FY-CHO (10 μmol/L) or transfection with cathepsin L shRNA significantly increased the radiosensitivity of U251 cells.Both suppression and knockdown of cathepsin L in U251 cells also increased irradiation-induced apoptosis, as shown by the increased levels of Bax and decreased levels of Bcl-2.

View Article: PubMed Central - PubMed

Affiliation: Department of Pharmacology, College of Pharmaceutical Sciences, Soochow University, Suzhou 215000, China.

ABSTRACT

Aim: Cathepsin L is a lysosomal cysteine protease that plays important roles in cancer tumorigenesis, proliferation and chemotherapy resistance. The aim of this study was to determine how cathepsin L regulated the radiosensitivity of human glioma cells in vitro.

Methods: Human glioma U251 cells (harboring the mutant type p53 gene) and U87 cells (harboring the wide type p53 gene) were irradiated with X-rays. The expression of cathepsin L was analyzed using Western blot and immunofluorescence assays. Cell survival and DNA damage were evaluated using clonogenic and comet assays, respectively. Flow cytometry was used to detect the cell cycle distribution. Apoptotic cells were observed using Hoechst 33258 staining and fluorescence microscopy.

Results: Irradiation significantly increased the cytoplasmic and nuclear levels of cathepsin L in U251 cells but not in U87 cells. Treatment with the specific cathepsin L inhibitor Z-FY-CHO (10 μmol/L) or transfection with cathepsin L shRNA significantly increased the radiosensitivity of U251 cells. Both suppression and knockdown of cathepsin L in U251 cells increased irradiation-induced DNA damage and G2/M phase cell cycle arrest. Both suppression and knockdown of cathepsin L in U251 cells also increased irradiation-induced apoptosis, as shown by the increased levels of Bax and decreased levels of Bcl-2.

Conclusion: Cathepsin L is involved in modulation of radiosensitivity in human glioma U251 cells (harboring the mutant type p53 gene) in vitro.

No MeSH data available.


Related in: MedlinePlus

Effect of cathepsin L inhibition on irradiation (IR)-induced apoptosis. Annexin V-FITC/PI staining and flow cytometry determination of apoptosis in U251 cells that were pretreated with Z-FY-CHO at 10 μmol/L (or untreated) for 12 h. The resulting cells were treated with 8 Gy IR and analyzed at 48 and 72 h post-IR. Mean±SD. n=3. bP<0.05, cP<0.01 compared with the control group. eP<0.05, fP<0.01 compared with the IR group.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC4561966&req=5

fig7: Effect of cathepsin L inhibition on irradiation (IR)-induced apoptosis. Annexin V-FITC/PI staining and flow cytometry determination of apoptosis in U251 cells that were pretreated with Z-FY-CHO at 10 μmol/L (or untreated) for 12 h. The resulting cells were treated with 8 Gy IR and analyzed at 48 and 72 h post-IR. Mean±SD. n=3. bP<0.05, cP<0.01 compared with the control group. eP<0.05, fP<0.01 compared with the IR group.

Mentions: To confirm the role of cathepsin L inhibition in apoptosis, the levels of apoptosis in U251 cells treated as described above were also measured by flow cytometry. We found that cathepsin L inhibition resulted in a higher percentage of early apoptotic cells at 72 h post-IR in U251 cells. However, an insignificant difference was observed between the Z-FY-CHO+IR treatment and IR alone treatment at the 48 h time point (Figure 7).


Cathepsin L suppression increases the radiosensitivity of human glioma U251 cells via G2/M cell cycle arrest and DNA damage.

Zhang QQ, Wang WJ, Li J, Yang N, Chen G, Wang Z, Liang ZQ - Acta Pharmacol. Sin. (2015)

Effect of cathepsin L inhibition on irradiation (IR)-induced apoptosis. Annexin V-FITC/PI staining and flow cytometry determination of apoptosis in U251 cells that were pretreated with Z-FY-CHO at 10 μmol/L (or untreated) for 12 h. The resulting cells were treated with 8 Gy IR and analyzed at 48 and 72 h post-IR. Mean±SD. n=3. bP<0.05, cP<0.01 compared with the control group. eP<0.05, fP<0.01 compared with the IR group.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4561966&req=5

fig7: Effect of cathepsin L inhibition on irradiation (IR)-induced apoptosis. Annexin V-FITC/PI staining and flow cytometry determination of apoptosis in U251 cells that were pretreated with Z-FY-CHO at 10 μmol/L (or untreated) for 12 h. The resulting cells were treated with 8 Gy IR and analyzed at 48 and 72 h post-IR. Mean±SD. n=3. bP<0.05, cP<0.01 compared with the control group. eP<0.05, fP<0.01 compared with the IR group.
Mentions: To confirm the role of cathepsin L inhibition in apoptosis, the levels of apoptosis in U251 cells treated as described above were also measured by flow cytometry. We found that cathepsin L inhibition resulted in a higher percentage of early apoptotic cells at 72 h post-IR in U251 cells. However, an insignificant difference was observed between the Z-FY-CHO+IR treatment and IR alone treatment at the 48 h time point (Figure 7).

Bottom Line: Irradiation significantly increased the cytoplasmic and nuclear levels of cathepsin L in U251 cells but not in U87 cells.Treatment with the specific cathepsin L inhibitor Z-FY-CHO (10 μmol/L) or transfection with cathepsin L shRNA significantly increased the radiosensitivity of U251 cells.Both suppression and knockdown of cathepsin L in U251 cells also increased irradiation-induced apoptosis, as shown by the increased levels of Bax and decreased levels of Bcl-2.

View Article: PubMed Central - PubMed

Affiliation: Department of Pharmacology, College of Pharmaceutical Sciences, Soochow University, Suzhou 215000, China.

ABSTRACT

Aim: Cathepsin L is a lysosomal cysteine protease that plays important roles in cancer tumorigenesis, proliferation and chemotherapy resistance. The aim of this study was to determine how cathepsin L regulated the radiosensitivity of human glioma cells in vitro.

Methods: Human glioma U251 cells (harboring the mutant type p53 gene) and U87 cells (harboring the wide type p53 gene) were irradiated with X-rays. The expression of cathepsin L was analyzed using Western blot and immunofluorescence assays. Cell survival and DNA damage were evaluated using clonogenic and comet assays, respectively. Flow cytometry was used to detect the cell cycle distribution. Apoptotic cells were observed using Hoechst 33258 staining and fluorescence microscopy.

Results: Irradiation significantly increased the cytoplasmic and nuclear levels of cathepsin L in U251 cells but not in U87 cells. Treatment with the specific cathepsin L inhibitor Z-FY-CHO (10 μmol/L) or transfection with cathepsin L shRNA significantly increased the radiosensitivity of U251 cells. Both suppression and knockdown of cathepsin L in U251 cells increased irradiation-induced DNA damage and G2/M phase cell cycle arrest. Both suppression and knockdown of cathepsin L in U251 cells also increased irradiation-induced apoptosis, as shown by the increased levels of Bax and decreased levels of Bcl-2.

Conclusion: Cathepsin L is involved in modulation of radiosensitivity in human glioma U251 cells (harboring the mutant type p53 gene) in vitro.

No MeSH data available.


Related in: MedlinePlus