DAPT suppresses the proliferation of human glioma cell line SHG-44

Objective:To explore the suppressing effect ofγ-secretase inhibitor DAPT on proliferation of human glioma cell line SHG-44 in vitro and its mechanism.Methods:The SHG-44 cell was treated by DAPT with different concentration.The proliferation of cells was detected by MTT assay;cell cycle and TSC of CD133^+were determined by flow cytometry analysis technique;the key factor in Notch signaling pathway(Notch-1,Delta-1,Hes-1)was measured by reverse transcrip tase-polymerase chain reaction and western blotting.Results:DAPT inhibited the growth and proliferation of SHG-44 cells significantly(P<0.05).And the inhibiting effect on SHG-44 cells produced by DAPT showed a dose-dependent manner.DAPT increased the rate of cells in G_0/G_1 phase of SHG-44 cells,while it decreased the rate of cells in S phase.TSC of CD133^+was significantly reduced after DAPT treated SHC-44 cells.The expression of protein and mRNA of Notch-1,Delta-1 and Hes-1 were gradually downregulated with the increase of DAPT doses.Conclusions:DAPT can downregulate these key factor in Notch signaling pathway,reduce the TSC of CD133+and inhibit the proliferation of SHC-44 cells.

Antitumor effect of tumor necrosis factor-related apoptosis inducing ligand combined with mevastatin on a human glioma cell line SWO-38

BACKGROUND： Previous studies have reported that statins are less toxic to the human body and have greater antitumor activity; however, few studies have addressed the antitumor effect of statins combined with tumor necrosis factor-related apoptosis inducing ligand （TRAIL）. OBJECTIVE： To explore the effect of TRAIL combined with mevastatin on the proliferation and apoptotic cell death of a human glioma cell line SWO-38, and to study its mechanism of action. DESIGN, TIME AND SETTING： An in vitro control experiment was performed at the Central Laboratory of the Third Hospital Affiliated to Sun Yat-sen University, between January and April 2009. MATERIALS： The human SWO-38 cell line was provided by Cell Research, Department of Animal Experimental Center of Sun Yat-sen University; human recombinant soluble TRAIL by R＆D, USA; and mevastatin by Sigma, USA. METHODS： SWO-38 cells were separately incubated in TRAIL （100, 200, 300, 400, and 500 tJg/L） and mevastatin （5, 10, 20, 30, and 40 pmol/L） for 72 hours. In addition, SWO-38 cells were incubated in TRAIL （300 μg/L）, mevastatin （30 μmol/L）, and a solution containing both TRAIL and mevastatin for 12, 24, 48 and 72 hours. MAIN OUTCOME MEASURES： Cell proliferation was detected using methyl thiazolyl tetrazolium assay; cell apoptosis was observed using Hoechst 33258 staining and fluorescence microscopy and was measured using Annexin V/propidium iodide flow cytometry; TRAIL R1/DR4 and TRAIL R2/DR5 protein expressions levels were measured using indirect immunofluorescence staining combined with flow cytometry in the recombinant soluble TRAIL （rsTRAIL, 300 tJg/L）, mevastatin （30 IJmol/L） and combination groups; TRAIL R1/DR4 and TRAIL R2/DR5 mRNA expression was detected using real-time polymerase chain reaction. RESULTS： rsTRAIL, mevastatin and their combination inhibited tumor proliferation in a time- and dose-dependent manner. The proliferation inhibitory rate and apoptosis rate of human SWO-38 cells in the combined group were significantly greater than the rsTRAIL or mevastatin alone group （P 〈 0.01）. TRAIL R1/DR4 and TRAIL R2/DR5 protein and mRNA expressions were increased in the combination group compared with mevastatin or rsTRAIL alone after 72 hours （P 〈 0.01）. CONCLUSION： Both rsTRAIL and mevastatin inhibit the proliferation and apoptosis of the human glioma cell line SWO-38, while their combination enhances the anti-tumor effect. The mechanism of action possibly correlates to the upregulation of TRAIL R1/DR4 and TRAIL R2/DR5 mRNA expression by mevastatin, thereby enhancing the cell sensitivity to rsTRAIL.

Establishment of an untransfected human corneal epithelial cell line and its biocompatibility with denuded amniotic membrane

AIM: To establish an untransfected human corneal epithelial (HCEP) cell line and characterize its biocompatibility with denuded amniotic membrane (dAM). METHODS: The torn HCEP pieces were primarily cultured in DMEM/F12 media (pH 7.2) supplemented with 20% fetal bovine serum and other necessary factors, yielding an HCEP cell line which was its growth performance, chromosome morphology, tumorigenicity and expression of marker proteins analyzed. In addition, the biocompatibility of HCEP cells with dAM was evaluated through histological and immunocytochemistry analyses and with light, electron and slit-lamp microscopies. RESULTS: HCEP cells proliferated to confluence in 3 weeks, which have been subcultured to passage 160. A continuous untransfected HCEP cell line, designated as utHCEPC01, was established with a population doubling time of 45.42 hours as was determined at passage 100. The cells retained HCEP cell properties as were approved by chromosomal morphology and the expression of keratin 3. They, with no tumorigenicity, formed a multilayer epithelium-like structure on dAMs through proliferation and differentiation during air-liquid interface culture, maintained expression of marker proteins including keratin 3 and integrin p 1 and attached tightly to dAMs. The reconstructed HCEP was highly transparent and morphologically and structurally similar to the original. CONCLUSION: An untransfected and non-tumorigenic HCEP cell line was established in this study. The cells maintained expression of marker proteins. The cell line was biocompatible with dAM. It holds the potential of being used for in vitro reconstruction of tissue-engineered HCEP, promising for the treatment of diseases caused by corneal epithelial disorders.

Melatonin and Doxorubicin synergistically induce cell apoptosis in human hepatoma cell lines

AIM:To investigate whether Melatonin has synergistic effects with Doxorubicin in the growth-inhibition and apoptosis-induction of human hepatoma cell lines HepG2 and Bel-7402.METHODS:The synergism of Melatonin and Doxorubicin inhibited the cell growth and induced cell apoptosis in human hepatoma cell lines HepG2 and Bel-7402.Cell viability was analyzed by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide(MTT)assay.Cell apoptosis was evaluated using TUNEL method and flow cytometry.Apoptosis-related protein Bax,Bcl-2 and caspase-3 expressions were measured by immunohistochemical staining.RESULTS:Treatment with Melatonin(10 -8 -10 -5 mol/L) alone had a dose-related inhibitory effect on cell proliferation but no cytotoxic effect on hepatoma cell lines HepG2 and Bel-7402.Interestingly,when combined with Doxorubicin,Melatonin significantly increased the effects of cell growth inhibition and cell apoptosis.Furthermore,TUNEL staining and flow cytometry revealed that cooperative apoptosis induction was associated with decreased expression of Bcl-2 as well as increased expression of Bax and Caspase3.CONCLUSION:The synergism of Melatonin and Doxorubicin inhibits hepatoma cell growth and induces cell apoptosis.

Recombinant human zona pellucida proteins ZP1, ZP2 and ZP3 co-expressed in a human cell line

Aim: To produce biologically active recombinant human (rh) ZP proteins in a human cell for use in sperm function tests. Methods: The human embryonic kidney cell line 293T was employed to produce rhZP1, rhZP2 and rhZP3 proteins individually and together by co-expression. Presence of these proteins in the culture medium and cell lysate was assessed by Western blotting analysis. The effect of the recombinant proteins on the human AR was assessed. Results: RhZP2 and rhZP3 were secreted into the culture medium, whereas rhZPl was found only in the cell lysate. Interestingly, when all zona pellucida proteins were co-expressed in the same cells, rhZPl was also secreted into the culture medium. However, despite the presence of all three ZP proteins in sufficient concentration and evidence of heavy glycosylation on gel electrophoresis, biological activity to induce the AR was not observed. Conclusion: RhZP1, rhZP2 and rhZP3 were successfully expressed in the human embryonic kidney cell line 293T. It appears that an interaction amongst these proteins may be required for release of rhZPl from the cell. Although this approach is not satisfactory for producing active human ZP proteins, it makes a significant contribution to the understanding of the structural and functional characteristics of the ZP proteins.

Establishment of an untransfected human corneal stromal cell line and its biocompatibility to acellular porcine corneal stroma

AIM: To establish an untransfected human corneal stromal (HCS) cell line and characterize its biocompatibility to acellular porcine corneal stoma (aPCS). METHODS: Primary culture was initiated with a pure population of HCS cells in DMEM/F12 media (pH 7.2) containing 20% fetal bovine serum and various necessary growth factors. The established cell line was characterized by growth property, chromosome analysis, tumorigenicity assay, expression of marker proteins and functional proteins. Furthermore, the biocompatibility of HCS cells with aPCS was examined through histological and immunocytochemistry analyses and with light, electron microscopies. RESULTS: HCS cells proliferated to confluence 2 weeks later in primary culture and have been subcultured to passage 140 so far. A continuous untransfected HCS cell line with a population doubling time of 41.44 hours at passage 80 has been determined. Results of chromosome analysis, morphology, combined with the results of expression of marker protein and functional proteins suggested that the cells retained HCS cell properties. Furthermore, HCS cells have no tumorigenicity, and with excellent biocompatibility to aPCS. CONCLUSION: An untransfected and non-tumorigenic HCS cell line has been established, and the cells maintained positive expression of marker proteins and functional proteins. The cell line, with excellent biocompatibility to aPCS, might be used for in vitroreconstruction of tissue-engineered HCS.

Growth and radiosensitivity of irradiated human glioma cell progeny

BACKGROUND： Progenitors of the immortalized human glioma cell line, SHG-44, are significantly less sensitive to irradiation. Two hypotheses regarding the mechanism of this effect exist： several studies have suggested that there is a subgroup with different radiosensitivities in identical cell group, and the progenitors of irradiate is a adaptive response subgroup, so its radiosensitivity is descend. A second hypothesis suggests that irradiated glioma progeny have a stronger ability to repair DNA damage. This would suggest that when progeny are continuously irradiated, resistance to irradiation-induced DNA increases, and radiosensitivity decreases. OBJECTIVE： To investigate radiosensitivity and growth features after irradiation to progeny of the human glioma cell line SHG-44. DESIGN, TIME AND SETTING： A randomized, controlled experiment, which was performed at the Department of Radiology Laboratory, the First Hospital Affiliated to Soochow University, between September 2004 and January 2006. MATERIALS： The glioma cell line SHG-44 was provided by the Institute of Neuroscience, First Affiliated Hospital of Suzhou University. Propidium iodide reagent was provided by Coulter Corporation. A linear accelerator, KD-2 type, was provided by Siemens, Germany. The flow cytometer EPICS-XL was provided by Coulter Corporation. METHODS： Brain glioma SHG-44 cells were divided into four groups： SHG-44, SHG-44-2, SHG-44-6, and SHG-44-10 . The SHG-44-2, SHG-44-6, and SHG-44-10 cells were vertically irradiated with varying doses of 2, 6 and 10 Gy by a linear accelerator （6 MVX）. The cells were passaged for 15 generations and cultured in RPMI-1640 culture media. MAIN OUTCOME MEASURES： Community re-double time, mean lethal dose （D0）, extrapolation number （N）, fraction surviving fraction irradiated by 2 Gy dose （SF2）, quasi-threshold dose （Dq）, and cell cycle. RESULTS： The Population doubling time （PDT） of SHG-44-2, SHG-44-6, and SHG-44-10 cell groups was not significant （P = 0.052）. Compared to these three groups, the PDT of the SHG-44 cell group was significantly difference （F = 7.878, P 〈 0.002）. SHG-44 cell clone ratewas 26.5%, and SHG-44-10 cell group was 15.5%. The SHG-44-10 cell group also exhibited radiosensitivity, but was less than the radiosensitivity of the SHG-44 cell group. Compared to the SHG-44 cell group, the ratio of the G2/M phase was decreased in the SHG-44-10 cell group, and the radio of S phase was increased. The SHG-44 and SHG-44-10 cell groups were irradiated with 8 Gy. After 12 hours, the G2/M ratio was compared to pre-irradiation times, indicating a significantly higher ratio in the pre-irradiated groups （P 〈 0.01）. The cells between S HG-44 and SHG-44-10 groups were harvested 12 hours after irradiation： G2 phase of SHG-44-10 cells was arrested and the G2/M ratio was increased, which was intensified with increasing irradiation doses. CONCLUSION： In the present study, the proliferation delay and decreased radiosensitivity were confirmed in progeny of irradiated human glioma cells, and radiosensitivity was dose-dependent.

Establishment of a Human Malignant T Lymphoma Cell Line Carrying a Retrovirus-like Particles with RT Activity

We have established an IL-2 independent malignant lymphoma line (CM-1) from peripheral T lymphocytes donated by a femalc patient with nervous systcm disease, the binlogical characteristics of CM-1 cells was studied in this paper. Another T lymphocytes,such as peripheral T lymphocytes donated by a maIe patient with multiple sclerosis, could be transformed into a malignant lymphoma line by using filtered supernatant of the CM-1 cultured medium, thus the CM-2 cell line u'as estabIished. The CM-1 and CM-2 cells were transplanted by subcutaneous inoculation into nude mice, and could cause the occurrenceof typical maIignant lymphoma. The observation of eIectron micrographs suggested the existence of virions in the CM-1 and CM-2 cells, and these virions were similar toretrovirus in the ultra-structure characteristics. lt was found that this virus possesses reverse transcriptase activity. ResuIts obtained from serological assay, molecular hybridization and PCR excluded the existence of other human viruses, which were commonly usedin our laboratory. The unknown virus possesses strong transformation activity, and probably is a new retro virus. Meanwhile, the work on the clone and sequence analysis ofthis virus are being carried out.

THE DIFFERENTIATION OF HUMAN GASTRIC ADENOCAR-CINOMA CELL LINE MGc80-3 INDUCED BY DIBUTYRYL cAMP IN VITRO

For providing some experimental basis in establishing malignant phenotypic reversed indexes of gastric carcinoma cells, human gastric adenocar-cinoma cell line MGc80-3 was induced by dBcAMP in vitro to appraise the effect of gastric carcinoma cell differentiation by chemical inducers.Under light microscope, MGc80-3 cells, after treated with 1 mM dBcAMP, tended to be flat and disperse, and their volume gradually enlarged, with their uncleus relatively smaller and their shape rather regular. Morphological changes, like norma differentiated epithelial cells, were observed. The cells attached firmly, grew slowly, their growth curve showed inhibitory rate amounted to 52.87%, and cellular division exponent displayed their peak value 1.5 times less than that of MGc80-3 cells. It was clear that dBcAMP could effectively inhibit the multiplication activity of MGc80-3 cells. After dBcAMP treatment, remarkable changes of cell surface charges was indicated by cell electrophoresis, the ratio dropped to 3.043 from 3.988, and their re-tardant ratio reached up to 31.2%. cAMP content in cells after this treatment, detected by cAMP and cGMP radioimmunoassay, was enhanced by 2.42 times, and cAMP/cGMP ratio, by 1.73 times. Thus, cAMP level within MGc80-3 cells was raised obviously by dBcAMP. Heterotransplantation experiments showed that tuntorigenic rate of MGc80-5 cells (transplanted subcutaneously to BALB/c mice) amounted to 100%, and that of the cells after this treatment was only 5.6%. Their tumorigenic ability was extremely reduced.These results confirmed that dBcAMP was able to change malignant phenotypic characteristics of MGc80-3 cells and produce a reversed alteration: Thus, it has a remarkable inductive effect in differentiating gastric carcinoma cells. All these characteristics were also considered as the reference indexes in appraising reversed effect for the homologous cancer cells.

Effect of 80.55 MeV//u^(12)C^(6+) Ions on Radiosensitivity and Cell Cycle of Human Hepatoma Cell Lines

In this paper, the relationship between radiosensitivity, cell cycle alteration and the change of apoptosis in different human hepatoma cell lines irradiated by heavy ions were studied with the aim of building up the base data for clinical therapy. Exponentially growing hepatoma cell lines were irradiated by 80.55 MeV/u12C6＋ ions at a dose of 0 Gy, 0.5 Gy, 1 Gy, 2 Gy, 4 Gy and 8 Gy. The radiosensitivity was assessed by means of the colony-forming assay. The DNA content, the percentage of each cell-cycle phase and the apoptosis rate were obtained with flow cytometry methods. After the irradiation, the SF2 （survival fraction at 2 gray） of SMMC-7721 cells were evidently lower than that of HepG2 cells. The S phase arrest, G2/M phase arrest delay and the apoptosis in the two hepatoma cell lines varied with the increase of the dose and repair time. The heavy ions could obviously kill the human hepatoma cell lines. Compared to HepG2 cells, SMMC-7721 cells were more radiosensitive to 12C^6＋ ions.

THE STUDIES ON MONOCLONAL ANTIBODY SZ-39 AGAINST HUMAN GLIOMA CELLS

A hybridoma cell line SZ-39 secreting monoclonal antibody against the human glioma cell has been established by a fusion between NS-1 myeloma cells and spleen cells from mice immunized with human glioma cell lines. Monoclonal antibody (McAb) SZ-39 was analyzed by ELISA, quantitative absorption, indirect immunofluorescence and ABC immunohistology. McAb SZ-39 strongly bound to 9/10 glioma cell lines, 17/20 glioma tissues, weakly bound to one liver cancer cell line and 1/2 lung cancer line, but they did not band with other tested human cancer linse. NcAb SZ-39 have no cross-reaction with lymphocyte, ABC red blood cells, white blood cells, blood platelet, normal bone marrow cells, fibroblast cells and 12 normal human tissues.The result indicated the antigen recognized by McAb SZ-39 may be a glioma-associated antigen <GAA). This GAA was analyzed by means of Western blotting. It was a MW 180 Kd glycopro-tein. The 131I-McAb SZ-39 specifically localized in human glioma xenografted in nude mice that indicate it may be useful in radioimmunoimaging and as a target for immunotherapy on human glioma.

Adiponectin Supports Human Glioma Cells Survival against Temozolomide through Enhancement of Autophagic Response in Glioma Cells

Objective: To investigate the role of adiponectin in human glioma cell lines against the temozolomide and the molecular regulation mechanism. Methods: Human glioma cell lines U251 and U-87MG were cultured in Dulbecco’s modified eagle medium (DMEM) containing 4500 mg/L glucose. MTT was used to measure cell growth ratio. Western blot was used to detect the protein levels of autophagy-related protein (Beclin 1, LC3 I/II, p62) and phosphorylated AMPK (p-AMPK) in human glioma cell lines. After AICAR and Compound C were administered, the change of p-AMPK and the autophagy level were examined by western blot. Results: While adiponectin stimulates AMPK in phosphatase and up-regulates the level of autophagy, human glioma cell lines obtain more resistance against the temozolomide, which is facilitated by AICAR and weakened by Compound C. Conclusion: As an important adipokine, adiponectin can up-regulate the glioma cell autophagy by activating the AMPK signaling pathway which increases the resistance of glioma cells to temozolomide.

CONDITIONED MEDIUM OF HUMAN NASOPHARYNGEAL CARCINOMA EPITHELIOID CELL LINE CNE_(1) CONTAINED THE ACTIVITIES OF TRANSFORMED GROWTH-INHIBITING FACTORS

The hormone defined serum free conditioned medium (SFCM) of human nasopharyngeal carcinoma epithelioid cell line (CNE1) was assayed by both the 3H-thymidine incorporation test and the soft agar test. It was found that the SFCM stimulated the growth of long-term serum-free cultured CNE4 cells in ac-cordence with the fact that the growth rate of long-term serum-free cultured CNE1 cells was directly proportional to the plating density. Alternatively 5% SFCM inhibited the growth of short-term serum-free cultured CNE4 cells by 51% in which the indicator cell remained the responsiveness state of growing in the serum-supplemented medium to the effector of interest. Furthermore, SFCM resulted in the inhibition of anchorage-independent growth of CNE4 cells and A431 cells. Also in soft agar test. SFCM reduced the colony formation of NRK(?),9F cells in the presence of EGF or EGF plus TGF-β. These finding suggested that CNE4 secreted autocrine growth stimulating factor(s) and growth inhibiting factor(s) in the serum-free medium, the latter strongly reverse malignant phenotypes of CNE4 and A431 cells in serum-supplemented surrounding.

Biological behaviors of two novel syngeneic human osteosarcoma cell lines

Objective To characterize and compare the different biological behaviors of two novel human osteosarcoma cell lines,Zos and Zos-M,established respectively from the primary site and the skip metastasis of an osteosarcoma patient.Methods Two

The influence of small interfering RNA on the expression of Survivin in human glioma cells

Objective This study aims to investigate the feasibility of knockdown of Survivin gene with small interfering RNA and to observe the apoptosis in gliomas which is influenced by siRNA. Methods Survivin specific siRNA oligonucleotides were designed and synthesized artificially. This siRNA

Modulating effects of survivin antisense oligonucleotide on changes of apoptosis and cell cycle of human hepatocellular carcinoma cell line SMMC-7721

To investigate the modulating effects of survivn antisense oligonucletode (ASODN) on the cell cycle and apoptosis of human hepatocellular carcinoma (HCC) cell line SMMC-7721 and explore its mechanism.Methods Survivin ASODN was transfected into SMMC-7721 cells mediated by DOTAP liposomal reagent.Electron microscopy,flow cytometry and RT-PCR were used to detect the changes in cell ultrastructure,apoptosis,cell cycle and the expression of cyclinB1 mRNA,respectively.Results After transfection of survivin ASODN,the expression of cyclinB1 mRNA in the cells significantly increased and increase in G2-M arrest and apoptosis appeared.Meanwhile,the cell ultrastructure had apoptotic changes such as chromatin condensation and apoptotic body formation.Conclusion Survivin ASODN can induce the expression of cyclinB1 that may result in G2-M arrest.Consequently,apoptosis is triggered.Survivin ASODN transfection might be an improtant new treatment for HCC.14 refs,2 figs,1 tab.

Orthotopical transplantation of human renal carcinoma tissue into nude mice and the establishment of a high metastatic cell line MRCC

Objective To establish a SOI model of human renal carcinoma and a high metastatic cell subline. Methods A human renal cell line RCC-9863 has been established by inoculating a human renal tumor tissue into nude mice s. c.. When RCC-9863 passaged for 20 times, the tissue from the same xemotransplant tumor were used to construct SOI model. Cultured the metastatic tissue in vitro, the tumor cell suspension was then injected orthotopically, The metastatic tissue obtained underwent the same procedure again. At last, the metastatic tumor was cultured in vitro and cloned. Results 15 days later, a tumor mass sized 1. 7 cm × 0. 6 cm in the nude mouse’s renal parenchyma was grown which lobulated, rude, and with multiply blood vessels and 55 days later later the mouse became moribund and metastases in the lungs were formed. The transplanted renal tumor in the SOI model grew fast and invasively and metastasized to lungs, lymphatic node and liver. A subline, MRCC, with metastatic ability to the lung was selected.

The establishment of stable transfection of human breast cancer cell line MDA-MD-468 with exogenous PTEN gene

To investigate exogenous PTEN gene transfected human breast cancer cell line MDA-MD-468.Methods Using the lipofectamine 2000 transfection technique,wild type PTEN gene was transducted into an in vitro cultured highly metastatic breast cancer cell line MDA-MD-468.After transfection,the cells were selected by G418.The resistant clones were chosen and expanded in DMEM culture medium.RT-PCR,immunohistochemical method and western blot were used to determine the expression of target genes.Results An anti-G418 cell clone was established and expanded in culture.The transfected PTEN gene MDA-MD-468 cells showed expression of PTEN mRNA and PTEN protein.Conclusion Human breast cancer cell line MDA-MB-468 established in this study expresses consistently exogenous PTEN genes.4 refs,6 figs.