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Ding Ma

Publications and source records attributed to Ding Ma.

At least 91 records · Page 5Linked to original sources
PubMed2003

[Selection of targets locating on the surface of epithelial ovarian cancer cells by using phage peptide library].

OBJECTIVE: The aim of this study was to select specific targets locating on the surface of epithelial ovarian cancer cells. METHODS: Peptide phage display library was used to isolate specific ligand to ovarian cancer cell receptors. The diluted library was incubated with the normal ovarian cells that primarily cultured before hand, and then the supernatant of nonbonding phage was added to the first epithelial ovarian cancer cell line A2780. Phage that binds to the cell surface are eluted and then amplified to be used in the next round. After the third round of panning, the elute was used as input phage for the next cell line biopanning. Four epithelial ovarian cancer cell lines were used one by one in this way. Finally the positive clones were identified by ELISA assay. Sequencing analysis was carried out for further identification. RESULTS: 10 positive clones were chosen and one was regarded as target clone. A candidate sequence (YYGLAEVDAGGS) was identified by amino acid sequence assay. CONCLUSION: The phage peptide library provides an efficient selection system for searching special targets locating on the cell surface.

Female↗
PubMed2003

[PTEN coding product: a marker for tumorigenesis and progression of endometrial carcinoma].

BACKGROUND & OBJECTIVE: A new candidate tumor suppressor gene, called phosphatase and tension homology deleted on chromosome ten (PTEN), was the first gene that was found to be phospholipase tumor suppressor gene. Loss of PTEN function by mutation or other mechanisms is closely related to tumorigenesis and progression of multiple carcinomas. This study was designed to investigate the expression of PTEN in carcinogenesis and development of endometrium carcinoma. METHODS: The expression of PTEN were detected by reverse transcription polymerase chain reaction (RT-PCR) for 24 cases with endometrial carcinoma, 10 cases with endometrial atypical hyperplasia, 10 cases with endometrial hyperplasia,and 10 cases with normal endometrium and by SP immunohistochemical methods for 73 cases with endometrial carcinoma, 25 cases with endometrial atypical hyperplasia, 71 cases with endometrial hyperplasia,and 31 cases with normal endometrium. The results were compared with clinical parameters (histological classification, differentiation, depth of myometrium invasion, and clinical stage). RESULTS: PTEN expression levels of both RNA and protein in patients with endometrial carcinoma and endometrial atypical hyperplasia were significantly lower than those in patients with endometrial hyperplasia and normal endometrium. mRNA relative values were 0.35+/-0.13, 0.46+/-0.11, 2.32+/-0.32, and 2.45+/-0.51, respectively. Loss of PTEN expression rates were 66.67% (38/57), 76.00% (19/25), 5.63% (4/71), and 0 (0/31), respectively. Loss of PTEN expression in patients with endometrial carcinoma was significantly related to histological classification (P< 0.0001) and differentiation (P=0.0349). It was not related to depth of myometrium invasion and clinical stage(P >0.05). CONCLUSION: Loss of PTEN expression is an early event in endometrial tumorigenesis. Detection of PTEN protein may be a diagnostic biomarker for the earliest endometrial precancers and adenocarcinoma.

Biomarkers, Tumor↗
PubMed2003

[Selective apoptosis in HeLa cells induced by sodium butyrate and its mechanism].

OBJECTIVE: To investigate apoptosis induced by sodium butyrate in cervix cancer cell line HeLa and primary human embryo lung fibroblasts and its mechanism. METHODS: Cell apoptosis was assessed by morphology, cell viability, DNA fragmentation, the percentage of sub-G1 cells and phosphatidylserine (PS) externalization. The effects of sodium butyrate on transcription of Bax and Bcl-2 was analyzed by RT-PCR. RESULTS: Sodium butyrate inhibited proliferation in a time and dose-dependant manner. The inhibition of proliferation in HeLa cells was more significant than that in primary human embryo lung fibroblasts. DNA fragmentation, sub-G1 peak and AnnexinV/PI by flow cytometry showed very high apoptosis rates in HeLa cells 72 hours after treated with sodium butyrate, while pretty low in primary human embryo lung fibroblasts. RT-PCR showed sodium butyrate had little effects on transcription of Bax and Bcl-2 in HeLa cells. CONCLUSION: Sodium butyrate can induce apoptosis in HeLa cells without changing the expression of Bax and Bcl-2. Sodium butyrate comparatively has little effects on fibroblasts.

Antineoplastic Agents↗
PubMed2003

[Significance of expression of T lymphoma invasion/metastasis gene in ovarian cancer cells].

OBJECTIVE: To study the role of T lymphoma invasion/metastasis gene 1 (Tiam1) and protein in ovarian tumor cells. METHODS: Expressions of Tiam1 mRNA, Rac1 mRNA, and Tiam1 protein in four ovarian tumor cells A2780, Caov3, Skov3, and SW626 were studied by using RT-PCR and Western blot, respectively. The cell migration ability was analyzed by in vitro invasion assay. RESULTS: Expressions of Tiam1 mRNA and protein, as well as Rac1 mRNA were detected in all four ovarian tumor cells. There was a strong direct correlation between the levels of Tiam1 and Rac1 mRNA expression and migration potentials of all four ovarian cancer cells in vitro experiments. The increased expressions of Tiam1 mRNA were coincident with those of Rac1 mRNA, with a parallel relationship (P = 0.003, r = 0.874). Levels of Rac1 mRNA expression were significantly correlated with the potentials of tumor cell migration (P = 0.042, r = 0.814). CONCLUSION: Tiam1-Rac1 signaling pathway plays a positive role in assessing tumor cell invasion and metastasis and provides a new target for gene therapy of ovarian cancer.

Cell Movement↗
PubMed2003

[Construction of PTTGas antisense expression vector and its inhibitory effects on human ovarian carcinoma cell line SK-OV-3].

BACKGROUND & OBJECTIVE: Pituitary tumor transforming gene (PTTG) is a new proto-oncogene and shows multiple actions of promoting tumorigenesis and metastasis. Most researches mainly focus on the problems of PTTG expression in different tumor tissues and its relative regulatory mechanisms, but no research of exploring the possibility of antisense blocking of PTTG gene has been reported by now. In present study, the authors constructed eukaryotic expression vector expressing full-length anti-sense PTTG mRNA and observed its blocking effect on the potential invasion of human ovarian carcinoma cell line SK-OV-3. METHODS: PCR primers containing designed enzyme cut sites were used for cloning full-length PTTG gene fragment, and the resulting PCR product was inserted into the eukaryotic vector pcDNA3.1 in the antisense direction. The recombinant vector was then transfected into SK-OV-3 by lipofectamine. The positive cell clone was screened by G418,PTTG,and bFGF at protein level expression were detected by Western blot analysis. The changes of cell proliferation were analyzed by MTT method. The biological behavior change of transfection positive cells was observed by colony formation in soft agar assay. RESULTS: SK-OV-3 clones stably expressing full-length recombinant pcDNA3.1- PTTGas were obtained.The expression of PTTG and bFGF proteins in transfected cells were decreased by 61.5% and 52.3% respectively as compared with non-transfected ones. The cell proliferation was accelerated in transfected cells. The number of colony formation is reduced significantly in transfected cells (2.4+/-0.8) as compared with non-transfected and empty vector transfected cells (23.3+/-5.7 and 21.5+/-7.9, respectively, P< 0.01). CONCLUSION: The recombinant vector pcDNA3.1-PTTGas is a novel tool and brings us a new possibility of anti-sense gene therapy targeted at PTTG in human carcinoma.

Cell Line, Tumor↗
PubMed2003

[Mdr-1 ribozyme in the reversal of multidrug resistance in human ovarian cancer].

OBJECTIVE: To study the mechanism of multidrug resistance and its reversal by mdr-1 ribozyme in human ovarian cancer. METHODS: The expression of mdr-1 and p-glycoprotein (p-gp) was studied by confocal laser microscope (Confocal), RT-PCR and Western blot analysis in adriamycin-resistant human ovarian cancer cell line (A2780/ADM) and adriamycin-sensitive one (A2780). The mdr-1 ribozyme was transfected into the A2780/ADM by Lipofectamine 2000 to overcome the multidrug resistance in ovarian cancer. RESULTS: The expression of mdr-1 mRNA and p-gp in A2780/ADM was significantly higher than that in A2780. The expression of mdr-1 mRNA and p-gp in A2780/ADM was lowered after being transfected by mdr-1 ribozyme. CONCLUSION: Multidrug resistance of A2780/ADM, possibly being caused by overexpression of mdr-1 gene, can be partially reversed by mdr-1 ribozyme.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed2003

[Killing effect of adenovirus vector-mediated herpes simplex virus thymidine kinase gene recombinant construct on various cancer cells].

BACKGROUND & OBJECTIVE: Adenovirus vector-mediated herpes simplex virus thymidine kinase gene (ADV-TK) transfer is one of the major gene therapy strategies for tumor. This study was designed to determine the in vitro anti-tumor efficiency of ADV-TK, a recombinant construct previously developed in our laboratory. METHODS: Herpes simplex virus thymidine kinase (TK) gene was transduced into 14 types of cultured tumor cells with different histological origins using adenovirus vector followed by ganciclovir (GCV) medication. The killing efficiency was measured using MTT assay. RESULTS: At the dosage of 1x10(9) viral particles/per well in the presence of 100 microg/ml GCV, ADV-TK/GCV caused effective killing of 11 out of total 14 types of tumor cells with a rate higher than 74%, the other 3 tumor cells, laryngeal epithelial cancer cells (Hep-2), hepatic cancer cells (Bel7402), and human colon cancer cells (HCT-8) were less sensitive to the ADV-TK/GCV treatment with the killing rates of 55.3%+/-2.0%, 61.3%+/-2.0%, and 63.7%+/-2.5%, respectively. Except for Hep-2, the killing efficiency caused by ADV-TK/GCV treatment was similar to that caused by cisplatin at a dosage equal to the in vivo peak concentration (5 microg/ml) in tissue. CONCLUSION: ADV-TK is highly efficient for active killing of tumor cells in vitro and is promising for future clinical application.

Adenoviridae↗
PubMed2003

[Antisense oligonucleotide reverses topotecan-resistant ovarian cancer cells].

BACKGROUND & OBJECTIVE: Breast cancer resistance protein (BCRP) was overexpressed in topotecan (TPT)-selected human ovarian cancer cell line A2780/TPT, strongly suggesting BCRP to be responsible for the drug-resistance of ovarian cancer. The current study was designed to investigate the reversal effect of BCRP antisense oligonucleotide (ASODN) on topotecan- resistant A2780/TPT cells. METHODS: The antisense-phosphorothioate oligonucleotide including the translation initiation site of BCRP mRNA was artificially synthesized, and the sense oligonucleotide (SODN) corresponding to the ASODN was also synthesized as control. Lipofect-2000 (LF) was used for the transfer of either ASODN or SODN into A2780/TPT cells. The changes of BCRP mRNA expression, intracellular fluorescence intensity of rhodamine and resistance index to topotecan of in vitro transfected A2780/TPT cells were detected respectively by reverse transcription-polymerase chain reaction (RT-PCR),flow cytometry (FCM),and methyl thiazolyl tetrazolium (MTT) assay. RESULTS: The transfer of ASODN/LF into A2780/TPT cells resulted in:(1)a 59.42% reduction of BCRP mRNA level (P< 0.05); (2)an obviously increased intracellular rhodamine fluorescence intensity from 5.42 to 16.63(P< 0.05); (3)a decreased resistance index to topotecan from 25 to 5 indicating sensitivity to topotecan in A2780/TPT cells recovered, as compared with non-transfected cell. But after transfecting SODN, no significant change could be measured. CONCLUSION: ASODN transfection may partly reverse BCRP-mediated drug- resistance of ovarian cancer cells.

ATP Binding Cassette Transporter, Subfamily G, Mem↗
PubMed2002

Towards guest-zeolite interactions: an NMR spectroscopic approach.

Guest(metal)-zeolite interactions in a two component heterogeneous catalyst have been investigated by high-field and high-speed (27)Al MAS NMR, and two-dimensional (27)Al MQ MAS NMR experiments as well as ab initio DFT methods. It was established that strong interactions between guest and zeolite occur in a metal/zeolite system, with the metal anchored to the tetrahedral aluminum framework site through two oxygen bridges. It disturbs the tetrahedral environment of associated aluminum framework, changing AlO(4) geometry from near T(d) to C(2v); this enables us to resolve this species from the undisturbed aluminum framework species in high-field (27)Al MAS NMR and two-dimesional (27)Al MQ MAS NMR experiments.

Journal Article↗
PubMed2002

Direct synthesis of uniform hollow carbon spheres by a self-assembly template approach.

Hollow carbon spheres (50-100 nm) have been synthesized by a self-assembly approach using hexachlorobenzene and Na. NaCl which generated during the reaction has been successfully exploited as a template for the direct synthesis of porous carbon materials, which can be subsequently removed from carbon product by annealing above 1400 degrees C.

Journal Article↗
PubMed2002

An investigation of the roles of surface aluminum and acid sites in the zeolite MCM-22.

Ammonia adsorption studies reveal that the observed Lewis acidity in the zeolite MCM-22 is derived from at least two types of framework aluminum sites (AlF), that is, octahedral AlF and three-coordinate AlF. Comparative ammonia or trimethylphosphine (TMP) adsorption experiments with MCM-22 confirm that octahedral Al species gives rise to the signal at delta(iso) approximately 0 in the 27Al NMR spectrum; this is a superposition of two NMR signals from the different Al species on the water-reconstructed zeolite surface. A sharp resonance assigned to framework Al reversibly transforms on ammonia adsorption to delta(iso)27Al approximately 55 from tetrahedral AlF, while the broad peak is assigned to nonframework aluminum which results from hydrothermal treatment. This study also demonstrates the effectiveness of 27Al magic angle spinning (MAS) and multiple quantum (MQ) MAS NMR spectroscopy as a technique for the study of zeolite reactions.

Journal Article↗
PubMed2002

[Role of vascular endothelial growth factor overexpression in ovarian tumor invasion and mechanism].

OBJECTIVE: To study the role of vascular endothelial growth factor (VEGF) overexpression in ovarian tumor metastasis and associated mechanism. METHODS: The VEGF cDNA was transfected into ovarian tumor cell lines CAOV3 and COC1. Transfected and nontransfected cells were screened for VEGF, gelatinase A (MMP-2) mRNA and protein by reverse transcription polymerase chain reaction (RT-PCR), Western blot and substrate zymography, respectively. The invasive ability of two ovarian tumor cell lines was analysed with Boyden chamber invasion assay before and after VEGF cDNA transfection. RESULTS: The expression of VEGF, MMP-2 mRNA and protein were increased (P < 0.05) after VEGF cDNA transfection, detected by RT-PCR, Western blot and substrate zymography. After VEGF cDNA transfection, the mean invasion percentage of two ovarian tumor cells [CAOV3: (42.5 +/- 4.1)%; COC1: (26.8 +/- 2.4)%] were higher than that before transfection [CAOV3: (24.7 +/- 1.9)%; COC1: (8.6 +/- 1.1)%, P < 0.05]. CONCLUSION: The expression of VEGF correlates to the in vitro invasion of ovarian tumor cell and induction of MMP-2 by VEGF is a key component of VEGF-induced ovarian tumor cell invasion.

DNA, Complementary↗
PubMed2002

[Effects of RelA antisense oligonucleotide on apoptosis of ovarian cancer cells COC1].

OBJECTIVE: To evaluate the effects of RelA antisense oligonucleotide on apoptosis of ovarian cancer cells. METHODS: COC1 cell line was treated with RelA antisense oligonucleotide combining with tumor necrosis factor (TNF)-alpha or paclitaxel at appropriate concentrations and duration. The apoptosis and RelA activation of ovarian cancer line COC1 cell were measured by indirect immunofluorescence, Western blot, flow cytometric analysis, DNA ladder assay. RESULTS: The apoptosis increased obviously in COC1 rells if treated by RelA antisense oligonucleotide combining with paclitaxel 50 micromol/L than paclitaxel 50 micromol/L only (27.4 +/- 0.5)% vs (12.3 +/- 0.6)% (P < 0.01), when treated 12 hs; (31.7 +/- 0.3)% vs (13.0 +/- 0.5)% (P < 0.01) when treated 24 hs. The apoptosis was also increased obviously in COC1 cells if treated by RelA antisense oligonucleotide combining with TNF-alpha 50 microgram/L than TNF-alpha 50 microgram/L alone. (30.8 +/- 0.3)% vs (13.2 +/- 0.4)% (P < 0.01). CONCLUSION: RelA antisense oligonucleotide may induce apoptosis susceptibility of COC1 cells to TNF-alpha or paclitaxel.

Apoptosis↗
PubMed2002

Cyclooxyenase-2 expression in endometrium carcinoma.

OBJECTIVE: To investigate the expression of cyclooxyenase-2 (COX-2) in carcinogensis and development of endometrium carcinoma. METHODS: Immunostainings, westernblotting and quantitve reverse transcription-polymerase chain reaction (RT-PCR) assay were utilized to measure levels of protein and mRNA expression of COX-2 in following five study groups: 25 cases with proliferative phase, 25 cases with secretory phase, 25 cases with endometritis, 23 cases with atypical proliferative phase and 34 cases with endometrium carcinoma. RESULTS: COX-2 expression of both RNA and protein in patients with endometrial carcinoma was higher significantly than patients with proliferative phase, secretary phase, endometritis, atypical proliferate phase. Immunostaining score was 5.46 +/- 0.12 vs 3.20 +/- 0.18, 4.78 +/- 0.12, 6.10 +/- 0.25, 8.70 +/- 0.93, average absorbent value was 0.75 +/- 0.23 vs 0.41 +/- 0.45, 0.56 +/- 0.31, 1.10 +/- 0.56, 1.46 +/- 0.41; concentration of mRNA [(93 +/- 8) vs (65 +/- 11), (79 +/- 6), (299 +/- 11), (493 +/- 30) fpg/ micro g respectively]. Successively the expression of COX-2 in atypical proliferation group was higher than normal endometrial and endometritis group. The expression in proliferative phase group was higher significantly than secretory phase group (P < 0.05). CONCLUSION: COX-2 may play an important role in the development of endometrial carcinoma.

Endometrial Neoplasms↗
PubMed2002

[Correlation of expression of vascular endothelial growth factor and matrix matalloproteinase-2 to invasion of ovarian tumor cells in vitro].

BACKGROUND & OBJECTIVE: Vascular endothelial growth factor(VEGF) and matrix metalloproteinase-2 (MMP-2) are the important factors in tumor metastasis. To the author's knowledge, their relationship has not been addressed to date. This study was designed to investigate the in vitro invasion and the expression level of VEGF and MMP-2 in ovarian tumor cells, and to evaluate the correlation of expression of VEGF and MMP-2 in the ovarian tumor metastasis. METHOD: Boyden chamber in vitro invasion assay was used to detect the invasive capacity in vitro in two ovarian tumor cell lines CaOV-3 and COC1. The expression levels of VEGF and MMP-2 in CaOV-3 and COC1 were evaluated by semiquantitative RT-PCR and Western blot. The activity of MMP-2 in two cell lines was detected by substrate zymography. RESULTS: Boyden chamber in vitro invasion assay indicated that the mean invasion percentage of CaOV-3 cells (21.9 +/- 1.5) was significantly higher than that of COC1 cells (8.8 +/- 0.9) (P < 0.05). Contrast to COC1 cells, CaOV-3 cells expressed significantly higher levels of mRNA of VEGF and MMP-2 as well as protein by RT-PCR and Western blot. Substrate zymography showed that the MMP-2 activity of CaOV3 cells was two times than that of COC1 cells. CONCLUSION: The in vitro invasive ability of ovarian tumor cells appeared to be positive correlated to high expression of VEGF and MMP-2. There may be relationship between VEGF and MMP-2 in the process of metastasis of ovarian carcinoma.

Endothelial Growth Factors↗