OBJECTIVETo explore the method of inducing and building pancreatic cancer cell sublines with radiation resistance.

METHODSSimulating the clinical radiotherapy, the pancreatic cell lines SW1990, Capan-1 (Cap), AsPC-1 (ASPC), P3, PANC-1 (Pan-1) and MIAPaCa-2 (MIA) were repeatedly given individual dose of X-rays with liner accelerator to induce radiation resistance, the changes of cell morphology, cell cycle and radio sensibility in the induced cell lines were compared with the parental cell lines at the end of inducing course.

RESULTSCompared with the parental cells, there were significant changes in morphology in the pancreatic cancer cell sublines after the radiation. Cell cycle analysis suggested that SW1990-R, ASPC-R, MIA-R, PAN-R and P3-R had lower G(2)/M and greater SF(2) (survival fraction after 2 Gy irradiation) compared with the parental cell lines.

CONCLUSIONSThe method of radiating cells step by step and repeatedly is viable to establish radio-resistant pancreatic cancer cell lines.

Cell Culture Techniques ; methods ; Cell Cycle ; radiation effects ; Cell Line, Tumor ; Cell Proliferation ; radiation effects ; Cell Shape ; radiation effects ; Cell Size ; radiation effects ; Cell Survival ; radiation effects ; Dose-Response Relationship, Radiation ; Humans ; Pancreatic Neoplasms ; pathology ; physiopathology ; Radiation Tolerance

OBJECTIVETo assess the effects of tumor necrosis factor-α (TNF-α) in enhancing the radiosensitivity of lung cancer cells in vitro.

METHODSA549 cells were exposed to γ-ray with or without TNF-α treatment. MTT assay was used to evaluate the cell viability, and flow cytometry was performed to assess the cell apoptosis. Western blotting was used to observe the expression of caspase-3 protein in the exposed cells.

RESULTSCompared with the exposed cells without TNF-α treatment, the cells treated with TNF-α showed significantly suppressed cell proliferation, increased the cell apoptosis, altered cell cycle, and increased caspase-3 protein expression after γ-ray exposure.

CONCLUSIONTNF-α can enhance the radiosensitivity of A549 cells to increase the efficiency of radiotherapy with γ-ray irradiation.

Apoptosis ; drug effects ; radiation effects ; Cell Cycle ; drug effects ; radiation effects ; Cell Line, Tumor ; Gamma Rays ; Humans ; Lung Neoplasms ; Radiation Tolerance ; drug effects ; Tumor Necrosis Factor-alpha ; pharmacology

Pulsed electromagnetic field (PEMF), a non-invasive physical treatment modality, is now used clinically to promote bone formation for osteoporosis. The patients after ectomy of ovarian cancer are easily complicated with osteoporosis. However, the safety parameters of PEMF treatment for the osteoporosis patients after resection of ovarian cancer remain unknown. Therefore, this study was designed to examine the effect of different frequency of PEMF on the proliferation, apoptosis and migration of human ovarian cancer cells (SKOV3 cells). Cultured SKOV3 cells were exposed to PEMF stimulation daily with radiation of 8 Hz, 16 Hz, 32 Hz and 64 Hz, respectively. We used sinusoidal waves with strength of 1 mT, twice a day with an interval of 12 hours. An exposure to the waves lasted 30 minutes, for 3 days, with those no PEMF stimulation serving as the control. The proliferation of cells was detected using EdU assay, and the apoptosis of cell was assessed with Annexin V-FITC fluorescence. The migration of cells was measured with the scratch wound assay. The data showed that exposure to PEMF of 1 mT, 8 Hz for 3 days could significantly inhibit the proliferation of SKOV3 cells and induce the apoptosis of the cells. The migrated distance and number were increased by 1 mT, 8 Hz or 32 Hz PEMF stimulation, but decreased by 1 mT, 16 Hz treatment. The results suggested that we should be careful about the safety of PEMF treatment and strictly choose the optical parameters in preventing or treating the osteoporosis of the patients after resection of ovarian cancer.
Apoptosis ; radiation effects ; Cell Line, Tumor ; Cell Movement ; radiation effects ; Cell Proliferation ; radiation effects ; Cystadenocarcinoma, Serous ; pathology ; Electromagnetic Fields ; adverse effects ; Female ; Humans ; Ovarian Neoplasms ; pathology

OBJECTIVETo study the effects of low frequency pulsed magnetic field on the proliferation and differentiation of HepG2 cells.

METHODS3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) colorimetry method and ELISA assay of alpha-fetoprotein (AFP) were used to determine the cell proliferation and differentiation after the cells were exposed to pulsed magnetic fields with different frequency but the same field intensity.

RESULTSThere were no significant differences in cell proliferation between sham and treated groups exposed to the field of 80 Hz, 1.55 mT for 1, 4, 8, 12, 24 h (P > 0.05). There were also no significant differences in cell proliferation and AFP secretion between sham and treated groups exposed to 16 Hz, 1.55 mT pulsed magnetic fields for 1, 4, 8, 24 h (P > 0.05).

CONCLUSIONThere were no "window effects" found in HepG2 cells proliferation or AFP secretion at 16 Hz and 80 Hz pulsed magnetic fields.

Cell Differentiation ; radiation effects ; Cell Division ; radiation effects ; Cell Line, Tumor ; cytology ; metabolism ; radiation effects ; Electromagnetic Fields ; Humans ; alpha-Fetoproteins ; analysis

OBJECTIVETo investigate the effect of X-rays on expression of caspase-3 and p53 protein in EL-4 cells and its implications in induction of apoptosis and polyploid cells.

METHODSMouse lymphoma cell line (EL-4 cells) was used. Fluorescent staining and flow cytometry analysis were employed for measurement of protein expression, apoptosis, cell cycle, and polyploid cells.

RESULTSThe expression of caspase-3 protein increased significantly at 8 h and 12 h, compared with that of sham-irradiated control (P<0.05, respectively) and the expression of p53 protein increased significantly at 2, 4, 8, 12, and 24 h, compared with that of sham-irradiated control (P<0.05-P<0.01) in EL-4 cells after 4.0 Gy X-irradiation. Apoptosis of EL-4 cells was increased significantly at 2, 4, 8, 12, 24, 48, and 72 h after 4.0 Gy exposure, compared with that of sham-irradiated control (P<0.05-P<0.001). G2 phase cells were increased significantly at 4, 8, 12, 24, 48, and 72 h (P<0.05-P<0.001). However, no marked change in the number of 8 C polyploid cells was found from 2 to 48 h after 4.0 Gy exposure.

CONCLUSIONThe expressions of caspase-3 and p53 protein in EL-4 cells are induced by X-rays, which might play an important role in the induction of apoptosis, and the molecular pathway for polyploid formation might be p53-independent.

Animals ; Caspase 3 ; metabolism ; radiation effects ; Caspases ; metabolism ; radiation effects ; Cell Line, Tumor ; Mice ; Tumor Suppressor Protein p53 ; metabolism ; radiation effects ; X-Rays

Cryptosporidium parvum is a well-known waterborne and opportunistic intracellular protozoan parasite that causes diarrheal illness. In this study, we quantitatively investigated reduction of the infectivity of C. parvum after gamma irradiation and repair of the infectivity during incubation time after irradiation. C. parvum oocysts were subjected to gamma irradiation at various doses (1, 5, 10, and 25 kGy), and the in vitro infectivity was measured by real-time PCR every day up to 7 days after irradiation. The in vitro infectivity of C. parvum on human ileocecal adenocarcinoma cells (HCT-8) was effectively reduced (> 2 log(10)) by irradiation at 10 kGy or more. However, in the experiment to find out repair of the infectivity, recovery was not noted until day 7 post-incubation.
Animals ; Cell Line, Tumor ; Cell Survival/radiation effects ; Cryptosporidiosis/*parasitology ; Cryptosporidium parvum/genetics/*pathogenicity/*radiation effects ; Female ; *Gamma Rays ; Humans ; Mice ; Mice, Inbred C57BL ; Oocysts/radiation effects ; Virulence

Adopting the cell model of multilayer spherical symmetry and the circuit analysis, the present paper gives the calculated results of the voltages on each of several parts of malignant Tonsillar B-cells and Jurkat T lymphocytes when the first-order Gaussian pulses at different central frequency apposed on them. The relationship between the central frequency and the transmembrane voltages of plasma membrane is also given. The optimum frequency causing electroporation in nuclear envelope is given as well. The paper discusses the reasons of electroporation in membrane and DNA degradation in nuclear. The work provides a reference for usage of transient bipolar electric pulses in cancer treatment.
Apoptosis ; radiation effects ; B-Lymphocytes ; cytology ; radiation effects ; Cell Line, Tumor ; Cell Membrane ; physiology ; Electromagnetic Fields ; Electroporation ; methods ; Humans ; Jurkat Cells ; Nuclear Envelope ; pathology ; radiation effects

OBJECTIVETo investigate the effects of radiosensitivity and X-ray dose on the expression of miR-7 in nasopharyngeal carcinoma (NPC) cells.

METHODSLow radiosensitive NPC cells CNE-1 and high radiosensitive NPC cells CNE-2 were exposed to 0, 2 and 8 Gy X-ray. The total RNAs of the cell lines were extracted 10 h after radiation for reverse transcription of miR-7 and 18S rRNA by stem-loop primer and random hexamers, respectively. The non-irradiated CNE-1 cells served as the control sample and the relative quantity of the expression level was calculated after real-time PCR using SyBR green.

RESULTSmiR-7 expression differed significantly between CNE-1 and CNE-2 cells (4.49-/+3.62 vs 1.29-/+1.10, F=135.483, P<0.001). The radiation dose also significantly affected the expression of miR-7 in NPC cells (F=39.565, P<0.001). CNE-1 cells with a 2 Gy exposure had the highest expression level of miR-7, while the non-irradiated CNE-1 cells had the lowest expression. CNE-2 cells exposed to 2 Gy X-ray had the lowest expression level of miR-7 and the non-irradiated CNE-2 cells had the highest.

CONCLUSIONRadiosensitivity and radiation dose of X-ray have significant effect on the expression of miR-7 in NPC cells, indicating that miR-7 plays an important role in radioresistance of NPC cells to X-ray, and suppressed miR-7 expression may elevate the radiosensitivity of NPC cells.

Apoptosis ; radiation effects ; Carcinoma ; Cell Line, Tumor ; Dose-Response Relationship, Radiation ; Gene Expression Regulation, Neoplastic ; radiation effects ; Humans ; MicroRNAs ; genetics ; Nasopharyngeal Neoplasms ; genetics ; Radiation Tolerance ; genetics ; X-Rays

OBJECTIVETo study the effects of GSM 1800 MHz radiofrequency electromagnetic fields (RF EMF) exposure on protein expression profile of human breast cancer cell line (MCF-7), as to exploring the possible effects on normal cell physiological function.

METHODSMCF-7 cells were continuously or intermittently (5 minutes field on followed by 10 minutes off) exposed to RF EMF for different duration (1 hour, 3 hours, 6 hours, 12 hours, or 24 hours) at an average specific absorption rate (SAR) of 3.5 W/kg. The extracted proteins were separated by 2-dimensional electrophoresis and the protein-spot distribution of the silver-stained gels was analyzed by using PDQuest software 7.1. Each experiment was repeated three times.

RESULTSOn the average, around 1100 proteins were detected using pH 4 - 7 IPG strip. There were no differential proteins found under continuous exposure at SAR of 3.5 W/kg for 6 hours. Under other exposure conditions, we found various differentially expressed proteins in exposure groups as compared with the sham-exposed controls. Especially in 3 hours intermittent exposure and 12 hours continuous exposure, eighteen and seven differential proteins were detected, respectively. The categories and functions of these differentially expressed proteins were analyzed by searching of SWISS-PROT protein database, which suggested that these proteins should be related to the functions of biosynthesization, signal transduction, and DNA damage and repair.

CONCLUSIONSData indicated that the protein expression changes induced by RF radiation might depend on exposure duration and mode. Many biological processes might be affected by RF exposure.

Cell Line, Tumor ; radiation effects ; Dose-Response Relationship, Radiation ; Electromagnetic Fields ; adverse effects ; Female ; Gene Expression ; Humans ; Proteome ; Radio Waves

BACKGROUND AND OBJECTIVEThe mRNA levels of 59 genes, detected by cDNA microarray, were up-regulated in the radioresistant human esophageal cacinoma cell line TE13R120 as compared with its parental cell line TE13 before and after radiation, and the expression of NRAGE gene showed a gradually up-regulating tendency. This study aimed to further detect the differences of NRAGE gene and protein expression and apoptosis between TE13R120 and TE13 cells, and to investigate the relationship between the NRAGE and the radioresistance of TE13R120 cells and its mechanism.

METHODSThe two cell lines were irradiated by ⁶⁰Co γ-ray at different conditions. Reverse transcription-polymerase chain reaction (RT-PCR), Western blot, and immunocytochemistry were used to detect the expression of NRAGE. Flow cytometry (FCM) was used to detect the cell apoptosis before and after irradiation.

RESULTSThe mRNA level of NRAGE was higher in TE13R120 cells than in TE13 cells before and after irradiation (before radiation: 0.25 ± 0.03 vs. 0.49 ± 0.03; 4 Gy 4 h: 0.31 ± 0.03 vs. 0.53 ± 0.02; 4 Gy 16 h: 0.32 ± 0.04 vs. 0.59 ± 0.04; 4 Gy 24 h: 0.36 ± 0.05 vs. 0.72 ± 0.04; 2 Gy 12 h: 0.32 ± 0.02 vs. 0.64 ± 0.04; 6 Gy 12 h: 0.36 ± 0.02 vs. 0.79 ± 0.05; 10 Gy 12 h: 0.46 ± 0.04 vs. 0.85 ± 0.01; P < 0.01), and the mRNA level of NRAGE was increased gradually with the increase of radiation dose and time in the two cell lines (P < 0.05 and P < 0.01). Western blot results showed no difference of NRAGE protein level in cytoplasm between TE13R120 cells and TE13 cells before and after irradiation, but its level in nuclei was higher in TE13R120 cells than in TE13 cells at different radiation time and dosages. Immunocytochemistry showed similar results as Western blot. FCM showed no significant difference in apoptosis rate between TE13R120 and TE13 cells before and after radiation.

CONCLUSIONNRAGE may play an important role in the radiation responses of the two cell lines, and may participate in the formation of radioresistance of TE13R120 cells by changing its subcellular localization, but its relationship with cell apoptosis has not been confirmed.

Antigens, Neoplasm ; genetics ; metabolism ; radiation effects ; Apoptosis ; radiation effects ; Cell Line, Tumor ; radiation effects ; Cobalt Radioisotopes ; Esophageal Neoplasms ; metabolism ; pathology ; Humans ; Neoplasm Proteins ; genetics ; metabolism ; radiation effects ; RNA, Messenger ; metabolism ; radiation effects ; Radiation Tolerance ; Radiotherapy Dosage ; Time Factors ; Up-Regulation