Limits...
Cucurbitacin B Causes Increased Radiation Sensitivity of Human Breast Cancer Cells via G2/M Cell Cycle Arrest.

Duangmano S, Sae-Lim P, Suksamrarn A, Patmasiriwat P, Domann FE - J Oncol (2012)

Bottom Line: Results.Flow cytometric analysis for DNA content indicated that cucurbitacin B resulted in G2/M arrest in MDA-MB-231 and MCF7:5C but not SKBR-3 cells.Therefore, combinations of cucurbitacin B with radiotherapy may be appropriate for experimental breast cancer treatment.

View Article: PubMed Central - PubMed

Affiliation: Faculty of Medical Technology, Mahidol University, Bangkok, Thailand.

ABSTRACT
Purpose. To explore the effects of cucurbitacin B on the radiation survival of human breast cancer cells and to elucidate the cellular mechanism of radiosensitization if any. Materials and Methods. Human breast carcinoma cell lines were treated with cucurbitacin B before irradiation with 0-10 Gy of (137)Cs gamma rays. The effect of cucurbitacin B on cell-survival following irradiation was evaluated by colony-forming assay. Cell cycle distributions were investigated using flow cytometry. Real-time PCR and western blots were performed to investigate the expression of cell cycle checkpoints. Results. Cucurbitacin B inhibited breast cancer cell proliferation in a dose-dependent manner. Only MDA-MB-231 and MCF7:5C cells but not SKBR-3 cells were radiosensitized by cucurbitacin B. Flow cytometric analysis for DNA content indicated that cucurbitacin B resulted in G2/M arrest in MDA-MB-231 and MCF7:5C but not SKBR-3 cells. Moreover, Real-time PCR and western blot analysis demonstrated upregulated p21 expression before irradiation, a likely cause of the cell cycle arrest. Conclusion. Taken together, these findings suggest that cucurbitacin B causes radiosensitization of some breast cancer cells, and that cucurbitacin B induced G2/M arrest is an important mechanism. Therefore, combinations of cucurbitacin B with radiotherapy may be appropriate for experimental breast cancer treatment.

No MeSH data available.


Related in: MedlinePlus

Cell death of breast cancer cells induced by cucurbitacin B. MCF7:5C, MDA-MB-231, and SKBR-3 were incubated with cucurbitacin B for 48 hr and apoptosis was analyzed by staining phosphatidylserine translocation with FITC-Annexin V. Annexin V staining is represented on the x-axis and PI staining is represented on the y-axis (a). The most representative result of three independent experiments is shown. Simple vertical bars represent the mean apoptosis rate of all of breast cancer cells (b). Results shown are the average of three independent experiments. *P < 0.05 versus nontreated control, **P < 0.01 versus nontreated control.
© Copyright Policy - open-access
Related In: Results  -  Collection


getmorefigures.php?uid=PMC3368438&req=5

fig3: Cell death of breast cancer cells induced by cucurbitacin B. MCF7:5C, MDA-MB-231, and SKBR-3 were incubated with cucurbitacin B for 48 hr and apoptosis was analyzed by staining phosphatidylserine translocation with FITC-Annexin V. Annexin V staining is represented on the x-axis and PI staining is represented on the y-axis (a). The most representative result of three independent experiments is shown. Simple vertical bars represent the mean apoptosis rate of all of breast cancer cells (b). Results shown are the average of three independent experiments. *P < 0.05 versus nontreated control, **P < 0.01 versus nontreated control.

Mentions: Apoptosis effect of cucurbitacin B was evaluated by using Annexin V-FITC and propidium iodide staining. This assay revealed that the negatively charged phospholipids phosphatidylserine found on the interior surface of the plasma membrane of the cells is trans-located to the cell surface during apoptosis. After 48 hr incubation with 0 μM, 2.5 μM, and 5 μM of cucurbitacin B, cells were stained and subjected to bivariate flow cytometric analysis. As shown in Figure 3, untreated cells did not show any significant apoptosis, whereas cells become apoptotic with cucurbitacin B treatment at the indicated concentration in all cells.


Cucurbitacin B Causes Increased Radiation Sensitivity of Human Breast Cancer Cells via G2/M Cell Cycle Arrest.

Duangmano S, Sae-Lim P, Suksamrarn A, Patmasiriwat P, Domann FE - J Oncol (2012)

Cell death of breast cancer cells induced by cucurbitacin B. MCF7:5C, MDA-MB-231, and SKBR-3 were incubated with cucurbitacin B for 48 hr and apoptosis was analyzed by staining phosphatidylserine translocation with FITC-Annexin V. Annexin V staining is represented on the x-axis and PI staining is represented on the y-axis (a). The most representative result of three independent experiments is shown. Simple vertical bars represent the mean apoptosis rate of all of breast cancer cells (b). Results shown are the average of three independent experiments. *P < 0.05 versus nontreated control, **P < 0.01 versus nontreated control.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3368438&req=5

fig3: Cell death of breast cancer cells induced by cucurbitacin B. MCF7:5C, MDA-MB-231, and SKBR-3 were incubated with cucurbitacin B for 48 hr and apoptosis was analyzed by staining phosphatidylserine translocation with FITC-Annexin V. Annexin V staining is represented on the x-axis and PI staining is represented on the y-axis (a). The most representative result of three independent experiments is shown. Simple vertical bars represent the mean apoptosis rate of all of breast cancer cells (b). Results shown are the average of three independent experiments. *P < 0.05 versus nontreated control, **P < 0.01 versus nontreated control.
Mentions: Apoptosis effect of cucurbitacin B was evaluated by using Annexin V-FITC and propidium iodide staining. This assay revealed that the negatively charged phospholipids phosphatidylserine found on the interior surface of the plasma membrane of the cells is trans-located to the cell surface during apoptosis. After 48 hr incubation with 0 μM, 2.5 μM, and 5 μM of cucurbitacin B, cells were stained and subjected to bivariate flow cytometric analysis. As shown in Figure 3, untreated cells did not show any significant apoptosis, whereas cells become apoptotic with cucurbitacin B treatment at the indicated concentration in all cells.

Bottom Line: Results.Flow cytometric analysis for DNA content indicated that cucurbitacin B resulted in G2/M arrest in MDA-MB-231 and MCF7:5C but not SKBR-3 cells.Therefore, combinations of cucurbitacin B with radiotherapy may be appropriate for experimental breast cancer treatment.

View Article: PubMed Central - PubMed

Affiliation: Faculty of Medical Technology, Mahidol University, Bangkok, Thailand.

ABSTRACT
Purpose. To explore the effects of cucurbitacin B on the radiation survival of human breast cancer cells and to elucidate the cellular mechanism of radiosensitization if any. Materials and Methods. Human breast carcinoma cell lines were treated with cucurbitacin B before irradiation with 0-10 Gy of (137)Cs gamma rays. The effect of cucurbitacin B on cell-survival following irradiation was evaluated by colony-forming assay. Cell cycle distributions were investigated using flow cytometry. Real-time PCR and western blots were performed to investigate the expression of cell cycle checkpoints. Results. Cucurbitacin B inhibited breast cancer cell proliferation in a dose-dependent manner. Only MDA-MB-231 and MCF7:5C cells but not SKBR-3 cells were radiosensitized by cucurbitacin B. Flow cytometric analysis for DNA content indicated that cucurbitacin B resulted in G2/M arrest in MDA-MB-231 and MCF7:5C but not SKBR-3 cells. Moreover, Real-time PCR and western blot analysis demonstrated upregulated p21 expression before irradiation, a likely cause of the cell cycle arrest. Conclusion. Taken together, these findings suggest that cucurbitacin B causes radiosensitization of some breast cancer cells, and that cucurbitacin B induced G2/M arrest is an important mechanism. Therefore, combinations of cucurbitacin B with radiotherapy may be appropriate for experimental breast cancer treatment.

No MeSH data available.


Related in: MedlinePlus