OBJECTIVE: To investigate the apoptosis of human breast cell line MCF-7 cells induced by gemcitabine and radiation. METHODS: The MTT method was applied to study the growth inhibition of MCF-7 treated with gemcitabine, radiation, gemcitabine and radiation. The apoptosis index (AI) was analyzed by flow cytometry. The morphology of the MCF-7 cells apoptosis was observed by transmission electron microscopy. RESULTS: When MCF-7 cells were treated with gemcitabine at different concentrations for 24 h, the cell growth inhibition rate was increased in a concentration-dependent manner. The apoptotic indexes (AI) of MCF-7 of four groups by flow cytometry revealed. The AI of (R+D) group was significantly different from those of the radiation group and the gemcitabine group (P<0.05). Condensed chromation, nuclear fragmentation and apoptotic body of MCF-7 cells were found by transmission electron microscope. CONCLUSION The apoptosis of human breast cancer cell line, MCF-7 cells, could be induced by gemcitabine. Gemcitabine can significantly enhance the radiation-induced apoptosis of MCF-7 cells.
Antimetabolites, Antineoplastic ; pharmacology ; Apoptosis ; drug effects ; radiation effects ; Breast Neoplasms ; pathology ; Deoxycytidine ; analogs & derivatives ; pharmacology ; Female ; Flow Cytometry ; Humans ; Radiation ; Radiation-Sensitizing Agents ; pharmacology ; Tumor Cells, Cultured

Several anticancer chemotherapeutic agents (5-fluorouracil, adriamycin and cisplatinum) and desferrioxamine, an iron chelator, were tested with regard to cytotoxicity and to the combined effect on radiation induced cell killing using two human hepatoma cell lines (HepG2 and PLC/PRF/5). Survival fractions were measured by quantitative colorimetric assay (MTT assay) and dose-response curves were plotted. MTT assay could be successfully used in the assessment of radiosensitivity in addition to chemosensitivity, because a good linear relationship between optical densities and cell numbers was observed and cells approached exponential growth for the first 7 days of culture when 5 x 10(3) or less cells were inoculated per well in our study. Steepness of the final slope (D0), width of the shoulder (D0) and the extrapolation number (n) of radiation survival curves were 1061.72 rad, 226.43 rad and 1.25 respectively in HepG2 and 1091.38 rad, 268.42 rad and 1.29 respectively in PLC/PRF/5. After combining anticancer chemotherapeutic agents and desferrioxamine with radiation, the widths of the shoulders were decreased whereas sensitizer enhancement ratios were increased as the concentration of drugs increased in both cell lines. These results suggest that neither anticancer chemotherapeutic agents nor desferrioxamine enhance cell killing induced by radiation alone, but suggested the possibility that they inhibit the repair of radiation damage.
Antineoplastic Agents/*pharmacology ; Carcinoma, Hepatocellular/*drug therapy/*radiotherapy ; Deferoxamine/*pharmacology ; Human ; Liver Neoplasms/*drug therapy/*radiotherapy ; Support, Non-U.S. Gov't ; Tumor Cells, Cultured/drug effects/radiation effects

The killing effect on S180 cells was studied using the combination of protoporphyrin IX and focused ultrasound at the frequency of 2.2 MHz and different intensities. Cell viability was determined by trypan blue exclusion test, morphology changes were evaluated by means of scanning electron microscopy and transmission electron microscopy after ultrasonic exposure. The results indicated that protoporphyrin IX(PPIX) alone showed no significant effect on S180 cells when compared with that of control group. Ultrasound alone and ultrasound combined with PPIX groups showed some anti-tumor effect, which became more noticeable as the ultrasound intensity and PPIX concentration increased, and when the concentration of PPIX increased to 120 microM, the ultrasound combined with PPIX exerted a more significant anti-tumor effect than did the ultrasound alone in the same experiment.
Animals ; Apoptosis ; drug effects ; radiation effects ; Mice ; Mice, Inbred ICR ; Photochemotherapy ; methods ; Photosensitizing Agents ; pharmacology ; Protoporphyrins ; pharmacology ; Sarcoma 180 ; pathology ; therapy ; Sonication ; Tumor Cells, Cultured ; Ultrasonics

OBJECTIVETo study the effect of dihydroartemisinin (DHA) combined irradiation on the apoptosis of human lung cancer GLC-82 cells and to study its mechanism.

METHODSThe growth inhibition rate of GLC-82 cells acted by different concentrations DHA was detected using MTT assay at 24, 48, and 72 h, respectively. Clone forming test was used. With multi-target single-hit model, the radiosensitization effect was assessed by calculating sensitizing enhancement ratio (SER).The effect of DHA combined irradiation on the apoptosis of GLC-82 cell cycle distribution and apoptosis were measured by flow cytometry. The protein expression of p53, p21, Bcl-2, and Bax were detected by Western blot.

RESULTSDifferent concentrations DHA (4, 8, 16, 32, 64, and 128 μg/mL) had cytotoxicity on GLC-82 cells. The IC50 for 24, 48, and 72 h was 38.25,20.58, and 10.36 μg/mL, respectively, in obvious dose- and time-dependent manner. The growth inhibition rate was more significantly increased than that of the blank control group (P < 0.01, P<0.05). DHA had sensitization enhancement effect on GLC-82 cells, with SER of 1.4. DHA combined irradiation could obviously change the structure of GLC-82 cells cell cycle and induce apoptosis (with the apoptosis rate of 21.5%), which was significantly different from that of the blank control group (P < 0.05). Western blot showed the expression of p53 and p21 protein could be increased by DHA combined irradiation, and the expression of Bcl-2 protein down-regulated (P <0.01, P <0. 05).

CONCLUSIONSDHA had stronger cytotoxicity and radiosensitization on GLC-82 cells. Its mechanisms might lie in making the arrest of GLC-82 cells' growth at G0/G1 phase, decreasing the ratio of cells at S phase, restoring the function of p53, decreasing the expression of Bcl-2 protein, and inducing apoptosis in GLC-82 cells.

Apoptosis ; drug effects ; Artemisinins ; pharmacology ; Cell Cycle ; drug effects ; Cell Proliferation ; drug effects ; Down-Regulation ; drug effects ; Flow Cytometry ; Humans ; Lung Neoplasms ; metabolism ; Neoplasm Proteins ; metabolism ; Radiation-Sensitizing Agents ; pharmacology ; Tumor Cells, Cultured ; bcl-2-Associated X Protein ; metabolism

AIMTo investigate the radiosensitizing effect and mechanism of action of staurosporine (STP) in human colon carcinoma HT-29 and breast cancer MCF-7/ADR cells.

METHODSThe effect of STP on the cytotoxicity of X-ray was determined by clonogenic assay. The effect of STP on cell cycle arrest induced by X irradiation was studied in two cell lines by using flow cytometry, Western Blotting was performed to indicate the changes of cyclin B1 and cdc2 protein levels.

RESULTSSTP sensitized the two cell lines to X-ray by clonogenic assay. STP potentiated the cytotoxicity of X-ray by 2.10- and 2.09-fold in HT-29 and MCF-7/ADR cells. Flow cytometry assay showed that exposure of HT-29 and MCF-7/ADR cells to X-ray caused cells arrest in G2 phase. The percentage of arrest G2 phase cells were 56% and 52.7%, respectively. The addition of STP after irradiation resulted in a dose-dependent reduction of G2 phase arrest induced by X-ray. Furthermore, the results showed that STP blocked decrease of cyclin B1 expression induced by X-ray, while mitotic index measurement indicated that X-ray-irradiated cells treated with STP entered mitosis. The data suggested that the potentiation of cytotoxicity of X-ray by STP is associated with the suppression of cyclin B1 expression, which result in the abrogation of G2 arrest, before the cells entered into M phase, they had not enough time to repair.

CONCLUSIONSTP is a potent G2 checkpoint abrogator and markedly enhanced the cytotoxicity of X irradiation in the p53 mutant cancer cells.

Breast Neoplasms ; pathology ; Cyclin B ; biosynthesis ; Cyclin B1 ; Enzyme Inhibitors ; pharmacology ; Female ; G2 Phase ; drug effects ; HT29 Cells ; Humans ; Mitotic Index ; Particle Accelerators ; Radiation Tolerance ; drug effects ; Radiation-Sensitizing Agents ; pharmacology ; Staurosporine ; pharmacology ; Tumor Cells, Cultured

Adjuvants, Immunologic ; pharmacology ; Animals ; Antineoplastic Agents, Phytogenic ; pharmacology ; Drug Resistance, Multiple ; drug effects ; Drug Resistance, Neoplasm ; drug effects ; Humans ; Platelet Aggregation Inhibitors ; pharmacology ; Pyrazines ; pharmacology ; Radiation-Protective Agents ; pharmacology ; Tumor Cells, Cultured ; drug effects

Animal ; Antineoplastic Agents, Phytogenic/isolation & purification/*pharmacology ; Chlorophyll/*analogs & derivatives/isolation & purification/pharmacology/radiation effects ; Comparative Study ; Drug Screening Assays, Antitumor ; Feces/*chemistry ; Hematoporphyrin Derivative ; Hematoporphyrins/pharmacology ; Human ; Leukocytes, Mononuclear/drug effects ; Mice ; Oxygen/metabolism ; Photochemistry ; Photochemotherapy ; Radiation-Sensitizing Agents/isolation & purification/*pharmacology ; Silkworms/*metabolism ; Singlet Oxygen ; Spectrophotometry ; Structure-Activity Relationship ; Support, Non-U.S. Gov't ; Tumor Cells, Cultured/*drug effects/radiation effects

OBJECTIVETo study the effect of X-ray on gene transfer and the antitumoral effect of X-ray combined with suicide gene therapy on colorectal carcinoma cells.

METHODSGreen fluorescent protein (GFP) was seen under fluorescent microscope. GFP gene was used for reporting gene to learn gene transfer efficiency and gene expressing time under the influence of radiation. G418 was used to select cytosine deaminase (CD) positive neoplasm cells and CD gene transfer efficiency was tested by cloning efficiency. Antitumoral effect of X-ray combined with CD and 5-FC on colorectal carcinoma cells was tested by MTT.

RESULTS4 Gy radiation could improve supercoiled plasmid DNA transfer efficiency for about 2 - 4 times and 30 times for linearized plasmid DNA. The mean durations of GFP gene expression treated with 4 Gy radiation were 14 d for supercoiled plasmid and 21 and for linearized plasmid, while in control group, the time was 12 d. Middle-dose radiation combined with CD and 5-FC could kill 99 percent of colorectal carcinoma cells, while in the control group, 5-FC only killed 15 percent of colorectal carcinoma cells which were transduced with CD gene.

CONCLUSIONSX-Ray combined with suicide gene therapy may be used as a promising method for treating colorectal neoplasm.

Antimetabolites ; pharmacology ; Cell Survival ; drug effects ; radiation effects ; Colorectal Neoplasms ; pathology ; Cytosine Deaminase ; Drug Interactions ; Flucytosine ; pharmacology ; Genetic Therapy ; Humans ; Nucleoside Deaminases ; genetics ; pharmacology ; Tumor Cells, Cultured ; X-Rays

OBJECTIVESTo investigate mechanism for the increasing level of serum vascular endothelial growth factor(VEGF) in tumour patients during radiotherapy and the inhibitory action of the antisense oligodeoxynucleotide (AS-ODN) to the expression of VEGF protein by radiotherapy in the prostate cancer cell line (PC3M).

METHODSTo observe the changes of serum VEGF in the prostate cancer patients during radiotherapy dynamically and the inhibitory action of the antisense oligodeoxynucleotide to the expression of VEGF by radiotherapy in PC3M.

RESULTSThe changes of serum VEGF in three patients receiving radiotherapy had been observed continuously. The levels of serum VEGF began to increase when the patients received radiotherapy and rised up to peak value after fifteen days, then declined to the range of pre-radiotherapy. Irradiating the PC3M cells with X-rays significantly increased the VEGF expression and secretion. The expression of VEGF protein in the group treated by VEGF AS-ODNs and X-ray irradiation decreased significantly than the group treated only by X-ray irradiation.

CONCLUSIONSThe induction of VEGF protein expression by X-ray irradiation in tumor cells may result in the increasing of the VEGF in the prostate cancer patients during radiotherapy and the induction can be blocked by VEGF AS-ODNs.

DNA, Antisense ; pharmacology ; Endothelial Growth Factors ; antagonists & inhibitors ; blood ; genetics ; Gene Expression ; drug effects ; radiation effects ; Humans ; Intercellular Signaling Peptides and Proteins ; blood ; genetics ; Lymphokines ; antagonists & inhibitors ; blood ; genetics ; Male ; Prostatic Neoplasms ; blood ; pathology ; Radiotherapy ; adverse effects ; Tumor Cells, Cultured ; Vascular Endothelial Growth Factor A ; Vascular Endothelial Growth Factors

OBJECTIVETo study the specific protection of myeloid cells from chemotherapeutic agents and radiation.

METHODSThe recombinant retroviral vectors containing MDR1 gene and MnSOD gene regulated by APN myeloid promoter were constructed and introduced into myeloblastic cell line KG1a and hepatoma cell line BEL7402. The resistance of the cells to antitumor drugs and radiation were analyzed by cell survival assay. In vivo, the murine bone marrow cells were isolated and infected by the retroviral particles, which were transplanted into recipient mouse treated with paclitaxel or X-ray. The murine white blood cell (WBC) was counted in order to assay the effects of MDR1 or MnSOD gene on hematopoiesis in the course of chemotherapy and radiotherapy.

RESULTSThe resistance to chemotherapeutic agents such as cochicine, Vp-16, vincristine, doxorubcin and paclitaxel were elevated markedly by 10.6, 10.4, 11.2, 4.2 and 14.2 folds in KG1a cell line transduced with MDR1 gene. The resistance to radiation increased 3.7 folds at the dose of 10 Gy compared with parental cells in KGla cell line transduced with MnSOD gene derived by APN promoter. In contrast, the chemosensitivity and the radiosensitivity showed no significant change in BEL 7402 cell line transduced with MDR1 gene and MnSOD gene. In vivo, the WBC counts in the mouse introduced with MDR1 gene or MnSOD gene were higher than those in the control mouse (P < 0.01).

CONCLUSIONThe expression of MDR1 gene and MnSOD gene regulated by APN myeloid promoter is effective on myelo-specific protection without enhancing the resistance of tumor cells in vitro. The hematopoiesis can be reconstituted in vivo during anticancer drug or radiation treatment. This study may provide experimental evidence and new clues for myeloprotection of cancer patients being treated with chemotherapy and/or radiotherapy.

ATP-Binding Cassette, Sub-Family B, Member 1 ; genetics ; pharmacology ; Animals ; Antineoplastic Agents ; pharmacology ; Bone Marrow ; drug effects ; physiology ; CD13 Antigens ; genetics ; Cell Survival ; drug effects ; Drug Interactions ; Etoposide ; pharmacology ; Gene Expression Regulation ; Gene Transfer Techniques ; Genetic Vectors ; genetics ; Male ; Mice ; Mice, Inbred BALB C ; Promoter Regions, Genetic ; Protective Agents ; pharmacology ; Radiation-Protective Agents ; pharmacology ; Superoxide Dismutase ; genetics ; pharmacology ; Tumor Cells, Cultured ; Vincristine ; pharmacology