Antitumor and antimetastatic effect of antimicrobial peptide conjugated with tumor homing peptide TMTP1 on the transplanted prostate cancer and gastric cancer in nude mice / 中华肿瘤杂志

<p><b>OBJECTIVE</b>Due to their lower risk for induction of resistance, antimicrobial peptides with selective anticancer effect could be developed into a new generation of anticancer drugs. We conjugated an antimicrobial peptide with tumor-targeting peptides (TMTP1) to explore whether it has inhibiting effect on the progression and metastasis of transplanted prostate cancer and gastric cancer in nude mice.</p><p><b>METHODS</b>Subcutaneously transplanted human prostate cancer and orthotopically transplanted human gastric cancer in nude mice were prepared. 50 µmol/L PBS (control group), 50 µmol/L TMTP1 (TMTP1 group) or 50 µmol/L TMTP1-GG-D(KLAKLAK)(2) (treatment group) were injected i.p. to the three groups of nude mice, respectively. The binding ability of the novel fusion polypeptide TMTP1-GG-D(KLAKLAK)(2) to the tumors and its antitumor effect were assessed by measurement of tumor volume, histopathological examination of the tumor tissues, testing apoptosis index of tumor cells with TUNEL staining, and survival curve plotting of the mice.</p><p><b>RESULTS</b>The median survival time of subcutaneous prostate cancer-bearing mice was 50 days in the control group, 55 days in the TMTP1 group, and 70 days in the TMTP1-GG-D(KLAKLAK)(2) group (P < 0.05). The median survival time of the subcutaneous gastric cancer-bearing mice was 25 days in the control group, 30 days in the TMTP1 group, and 45 days in the TMTP1-GG-D(KLAKLAK)(2) group (P < 0.01). The tumor volume in the subcutaneous prostate cancer-bearing mice was (2.5 ± 0.3)cm(3) in the control group, (1.8 ± 0.2) cm(3) in the TMTP1 group, and (0.3 ± 0.1)cm(3) in the TMTP1-GG-D(KLAKLAK)(2) group (P < 0.01). The tumor volume of the subcutaneous gastric cancer-bearing mice was (3.8 ± 0.4) cm(3) in the control group, (3.2 ± 0.2)cm(3) in the TMTP1 group, and (0.4 ± 0.1) cm(3) in the TMTP1-GG-D(KLAKLAK)(2) group (P < 0.01). Large tumors were observed in the stomach of the orthotopic gastric cancer-bearing mice of the control and TMTP1 groups. The tumor volume of the TMTP1-GG-D(KLAKLAK)(2) group was obviously reduced. White metastases in the liver, spleen and abdominal wall were observed in the control and TMTP1 groups (P < 0.01). TUNEL staining revealed that the apoptosis index of the control group was (31.9 ± 1.5)%, TMTP1 group (37.2 ± 2.3)% and TMTP1-GG-D(KLAKLAK)(2) group (69.7 ± 2.1)% (P < 0.01).</p><p><b>CONCLUSIONS</b>The results of our study demonstrate that the novel fusion peptide of antimicriobial peptide conjugated with TMTP1 can effectively inhibit tumor progression and metastasis, therefore, is promising to be a novel effective anticancer drug.</p>

Clinical analysis of 132 cases of cervical adenosquamous carcinoma and cervical adenocarcinoma / 癌症

<p><b>BACKGROUND AND OBJECTIVE</b>The incidence of cervical adenosquamous carcinoma is relatively low. This study was to analyze the clinicopathologic characteristics and prognostic factors of cervical adenosquamous carcinoma.</p><p><b>METHODS</b>Clinical data of 44 cervical adenosquamous carcinoma patients and 88 cervical adenocarcinoma patients(control), treated from January 2002 to December 2007, were analyzed using Chi-square test, Kaplan-Meier method, log-rank test, and Cox regression model.</p><p><b>RESULTS</b>The proportion of large tumors (maximal diameter > 4 cm) was significantly higher in cervical adenosquamous carcinoma group than in cervical adenocarcinoma group (47.7% vs. 28.4%, P<0.05); the proportion of poorly differentiated tumors was significantly higher in cervical adenosquamous carcinoma group than in cervical adenocarcinoma group (56.8% vs. 30.7%, P<0.05). Univariate analysis showed that tumor size (P=0.011), FIGO stage (P=0.013), depth of stromal invasion (P=0.05) and lymph node metastasis (P=0.017) were correlated with prognosis, while multivariate analysis showed that FIGO stage and lymph node metastasis had great impact on prognosis. There was no significant difference of 2-year overall and disease-free survival rates between the two groups (P>0.05).</p><p><b>CONCLUSIONS</b>Cervical adenosquamous carcinoma is characterized by large tumor size and poor differentiation. FIGO stage and lymph node metastasis are significant prognostic factors. There is no difference in prognosis between cervical adenosquamous carcinoma and cervical adenocarcinoma.</p>

Inhibitory effects of an antisense PCDGF vector on proliferation and invasion of highly malignant ovarian cancer cells and the related mechanism / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To investigate the inhibitory effects of an antisense PC cell derived growth factor (PCDGF) vector on proliferation and invasion of highly malignant ovarian cancer cell lines Sw626 and A2780 cells, and preliminarily explore the related mechanisms.</p><p><b>METHODS</b>MTT assay and Boyden chamber in vitro invasion assay were employed to detect the changes of proliferation and invasion ability in the Sw626 and A2780 cells transfected with anti-sense PCDGF. The expression levels of cyclin D1 and CDK4 proteins before and after transfection were detected by Western blotting. The effects on the expression and activity of MMP-2 were evaluated by quantitative RT-PCR and zymography, respectively.</p><p><b>RESULTS</b>Comparing with the blank group, the proliferation inhibition rate of the Sw626 and A2780 cells transfected with anti-sense PCDGF was 72.9% and 70.9%, respectively, and the invasion ability was inhibited by 62.9% and 59.0%, respectively. The levels of cyclin D1 and CDK4 protein expression in antisense PCDGF transfected cells were 0.38 +/- 0.08 and 0.37 +/- 0.13, respectively, all significantly lower than 0.84 +/- 0.11 and 0.64 +/- 0.11, respectively, in the blank group (P < 0.01). The MMP-2 mRNA expression level in antisense PCDGF transfected cell group was 0.66 +/- 0.11, not significantly decreased in comparison with 0.89 +/- 0.09 in the blank group (P > 0.05), but the activity of MMP-2 was inhibited significantly.</p><p><b>CONCLUSION</b>The antisense PCDGF vector may inhibit markedly the proliferation and invasion of highly malignant ovarian cancer cells, and partially reverses their malignant phenotype. It seems to be related with down-regulating the expression of cyclin D1 and CDK4 and inhibiting the activity of MMP-2. Our findings indicate that PCDGF may become a new target for antisense gene therapy of ovarian cancer.</p>

Down-regulation of Chk1/Chk2 gene expression increases apoptosis in irradiated HeLa cells and its mechanism / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To explore the increasing effect of blocking Chk1 and /or Chk2 gene by Chk1 or Chk2-specific antisense oligodeoxynucleotides (AsODN) on apoptosis in HeLa cell line after irradiation and its mechanism of action.</p><p><b>METHODS</b>Asynchronized HeLa cells were exposed to (60)Co-irradiation at different dosage to activate G(2)/M checkpoint arrest. The cell cycle profiles were observed in HeLa cells after irradiation at a range of various doses and different time points by flow cytometry. In the experimental groups, Chk1/2 sODN and AsODN alone or in combination were transfected into HeLa cells, and the cells were exposed to (60)Co-irradiation at 24 h after transfection. The changes of Chk1/2 protein expression were assayed by Western blot and confocal laser scanning microscopy (Confocal), and the cell cycles, apoptosis rates and cell cycle specific apoptosis were detected by annexin V-PI labeling and flow cytometry.</p><p><b>RESULTS</b>Apoptotic response was significantly increased in the Hela cells after G(2)/M arrest and was inversed to activation of G(2)/M checkpoint. Either Chk1 or Chk2-specific AsODN consistently enhanced DNA damage-induced apoptosis by 90% approximately 120%, compared to corresponding sODN control (P < 0.05). Unexpectedly, combined use of Chk1- and Chk2-specific AsODN did not produce synergistic effect as compared to treatment with Chk1- or Chk2-specific AsODN alone (P > 0.05). While irradiated HeLa cells underwent apoptosis preferentially in G(1)-phase, apoptosis occurred in either of G(1)-, S- or G(2)/M -phase in the presence of Chk1 and/or Chk2 AsODN.</p><p><b>CONCLUSION</b>The radioresistance is mainly induced by activating the cell cycle checkpoint signal transduction pathway after irradiation, and abrogating of the key effector Chk1 and Chk2 may increase the apoptotic sensitivity to irradiation due to changes of the pattern of cell cycle specific apoptosis.</p>

Silencing of cell cycle checkpoint kinase gene enhances cisplatin-induced apoptosis of lung cancer cells / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To investigate the changes in cell cycle induced by cisplatin (DDP) and the effect of antisense oligonucleotide (AsODN) targeting Chk1/2 on DDP-induced apoptosis in lung cancer cell line A549 cells.</p><p><b>METHODS</b>The characteristics of cell cycle and apoptosis induced by DDP were detected by flow cytometry using SubG1 method. Chk1/2 mRNA and protein expression were assayed by RT-PCR and Western blot under best condition of transfection of AsODN targeting Chk1/2 by lipofection. Apoptosis of A549 cells induced by DDP was determined by flow cytometry using AnnexinV-FITC staining after transfection of Chk1/2 AsODN.</p><p><b>RESULTS</b>Asynchronized A549 cells were treated with 10 micromol/L DDP, and significant S-phase arrest was observed at 12 h later. Transfection with antisense oligonucleotide targeting Chk1/2 inhibited the Chk1/2 expression at both mRNA and protein levels. Either Chk1 or Chk2-specific AsODN consistently enhanced DNA damage-induced apoptosis by 100% - 200%, compared with that in the sODN control (P < 0.05), but combined use of Chk1- and Chk2-specific AsODN did not show synergistic effects as compared with that induced by treatment with Chk1- or Chk2-specific AsODN alone (P > 0.05).</p><p><b>CONCLUSION</b>Chk1 and Chk2 may be regarded as effective targets of chemotherapy for lung cancer. Silencing the key effector Chk1 and Chk2 genes may significantly increase the chemosensitivity of lung cancer cells.</p>

Effect of hypoxia on the chemotherapeutic sensitivity of human ovarian cancer cells to paclitaxel and its mechanism / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To explore the effect of hypoxia and hypoxia-inducible factor-1alpha (HIF-1alpha) on the expression of multidrug resistance gene-1 (mdr-1) and its coded p-glyeoprotein (P-gp) as well as the chemotherapeutic sensitivity of human ovarian cancer cells to paclitaxel and its mechanism.</p><p><b>METHODS</b>The mRNA and protein levels of HIF-1alpha, mdr-1 and p-gp were studied by immunocytochemistry, semiquantitative reverse transcription-ploymerase chain reaction (RT-PCR) and Western blot analysis in human ovarian cancer cells (A2780) in 5% CO2 + 1% O2 hypoxic culture and 21% O2 normoxic culture, respectively. Methyl thiazolyl tetrazolium (MIT) was used to evaluate the chemotherapeutic sensitivity of A2780 cells to paclitaxel by inhibition rate. RNA interference technique was used and small hairpin RNAs (shRNAs) eukaryotic expression vector targeting HIF-1alpha was constructed as pSiHIF-1alpha, and transfected into A2780 cells. RT-PCR and Western blot were used to detect gene silencing effect on HIF-1alpha, the expressions of mdr-1 and p-gp. The inhibition rate was observed after HIF-1alpha gene silence.</p><p><b>RESULTS</b>HIF-1alpha at both mRNA and protein levels was induced significantly under hypoxia. The HIF-1alpha expression at mRNA level was oxygen gradient-independent, while HIF-1alpha expression at protein level was oxygen gradient-dependent. The inhibition rate of paclitaxel to hypoxic A2780 cells in 5% CO2 + 1% O2 was significantly lower than that in normoxic A2780 cells (P <0.05). The shRNAs plasmid targeting HIF-1alpha was constructed successfully and HIF-1alpha gene was silenced in A2780 cells efficiently followed by mdr-1 and p-gp down-regulation. The inhibition rate was greatly increased in hypoxic A2780/siHIF-1alpha cells.</p><p><b>CONCLUSION</b>Hypoxia can decrease the chemotherapeutic sensitivity of human ovarian cancer A2780 cells to paclitaxel through HIF-1alpha regulating the expression of mdr-1 and p-gp.</p>

Effect of blocking of ROCK-1, an effector of small G protein Rho, on the malignant behavior of ovarian tumor cells in vitro / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To investigate the possible role of ROCK-1 in ovarian cancer invasion and metastasis.</p><p><b>METHODS</b>ROCK-1 ASODN was transfected into SW626 and Caov-3 cell lines mediated by Lipofectamine 2000. The expressions of ROCK-1 mRNA and protein were detected by RT-PCR and Western-blot assay. Boyden chamber was used to assess the effect of ROCK-1 ASODN on the invasion and migration of the cell lines. The changes in the adhesion and proliferation of the transfected cells were detected by MTT assay.</p><p><b>RESULTS</b>The expressions level of ROCK-1 mRNA and protein in the cell lines were decreased significantly after transfection at doses of 10 micromol/L and 20 micromol/L ROCK-1 ASODN. When compared with the control group, the invasion capability of transfected cells was inhibited to an extent of 75.6% +/- 3.8% and 54.7% +/- 2.9%, respectively, for SW626 cell line, and 68.8% +/- 4.7% and 50.0% +/- 4.5% for Caov-3 cell line, respectively. The random migratory activity of these two cell lines was inhibited by 80.0% +/- 1.3%, 63.7% +/- 1.9%, 72.5% +/- 3.4% and 55.9% +/- 2.5%, respectively, and the inhibition of chemotaxis activity of the two cell lines was 83.9% +/- 1.4%, 64.1% +/- 1.3%, 72.5% +/- 3.4% and 54.5% +/- 1.9%, respectively. No significant difference was found in the adhesion and proliferation of the cells transfected with ROCK-1 ASODN and control cells.</p><p><b>CONCLUSION</b>The expression of ROCK-1 was closely related to the invasion capability and migratory activity of ovarian cancer cells. ROCK-1 may play a crucial role in invasion and metastasis of ovarian cancer.</p>

Role of human telomerase reverse transcriptase in apoptosis of human umbilical vein endothelial cells induced by trichostatin A / 中华肿瘤杂志

<p><b>OBJECTIVE</b>The aim of this study was designed to investigate the effect of TSA on human umbilical vein endothelial cells and to reveal its possible mechanisms and relationship between apoptosis and activity of telomerase reverse transcriptase.</p><p><b>METHODS</b>sulforhodamine B method was employed to determine the growth rate of umbilical vein endothelial cells. The cell apoptotic rate was measured by flow cytometry (FCM). The hTERT and p21(Waf1) mRNA expression before and after TSA treatment were detected by semiquantitative reverse transcription polymerase chain reaction (RT-PCR). The quantitative of hTERT protein expression in cells were detected by flow cytometry. After transfection, the cell telomerase activity was detected by PCR and telomeric repeat amplification protocol assay (PCR-TRAP-ELISA) and early apoptosis was measured by Annexin V/PI stain and flow cytometry.</p><p><b>RESULTS</b>After being treated with TSA, the proliferation of umbilical vein endothelial cells was inhibited. Slight apoptosis and cell cycle arrest were detected. However, the same concentration of TSA induced serious apoptosis in HeLa cells. Up-regulation of hTERT mRNA expression was observed within 48 h after TSA treatment, but the change of p21(Waf1) expression was not significant. The umbilical vein endothelial cells hTERT protein expression level was increased within 24 h. After transfection of the dominant negative, wild type and control hTERT plasmid, a significant difference of telomerase activity in these cells was observed by PCR-TRAP-ELISA assay. WT-hTERT-transfected cells were more resistant to apoptosis induced by trichostatin A.</p><p><b>CONCLUSION</b>Human umbilical vein endothelial cells could be resistant to apoptosis induced by high concentrate TSA, and hTERT might play an important role in this process.</p>

Influence of metastasis suppressor gene KAI1 on proliferation and invasion of endometrial carcinoma cells / 中国肿瘤生物治疗杂志

Objective:To investigate the influence of metastasis suppressor gene KAI1 on the proliferation,invasion and metastasis of endometrial carcinoma cell line AN3CA and HEC-1-B.Methods:The KAI1 cDNA was transfected into human endometrial carcinoma cells AN3CA and HEC-1-B via Lipofectamine 2000.The expression of KAI1 protein was ex- amined by Western blotting and flow cytometry before and after transfection.The proliferation ability of AN3CA and HEC- 1-B cells was observed by MTT assay and anchorage-independent growth assay.The changes of cell invasive ability were studied by transwell assays.Results:Stable expression of KAI1 protein was observed in AN3CA and HEC-1-B cells and on their surface after transfection with pcDNA3-KAI1 plasmid.Cells transfected with blank plasmid formed more colonies and had a larger size,with the colony forming rates being(54.2?3.1)% for AN3CA cells and(52.7?4.3)% for HEC- 1- B cells;the doubling time of AN3CA and HEC-1-B cells were 21.3 h and 20.1 h,respectively.Cells transfected with pcDNA3-KAI1 formed less colonies and had a smaller size,with the colony forming rates being(37.4?5.1)% for AN3CA cells and(32.1?3.7)% for HEC-1-B cells;the doubling time of AN3CA and HEC-1-B cells were 43.7h and 45.2 h,respectively.The cell proliferation abilities and colony-forming ability were significantly different between the two groups(P

Changes in telomerase activity decreases in MCF-7 cells during apoptosis induced by sodium butyrate / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To investigate telomerase activity of MCF-7 mammary cancer cells during apoptosis induced by sodium butyrate (SB) in vitro and its mechanism.</p><p><b>METHODS</b>The proliferative activity of MCF-7 cells was assessed by morphology and MTT assay. Cell apoptosis was confirmed by DNA fragmentation and phosphatidylserine (PS) externalization. Telomerase activity was examined by TRAP-ELISA. The expression status of telomerase subunits was analyzed by RT-PCR.</p><p><b>RESULTS</b>A time- and dose-dependent inhibition was detected in MCF-7 cells treated with SB. At 72 hr after SB (2.5 mmol/L) treatment, MCF-7 cells were apoptotic with a rate of 84.3% by flow cytometric assay (AnnexinV/PI double staining). Apoptosis was also confirmed by DNA fragmentation. Telomerase activity and expression level of hTERT, the key subunit of telomerase, decreased at 24-hour time point after SB treatment. No significant changes were observed in the expression of hTR and hTP, the other two subunits of telomerase.</p><p><b>CONCLUSION</b>Telomerase activity decreases in MCF-7 cells during apoptosis induced by sodium butyrate. The underlying mechanism might be related to the down regulation of hTERT transcription.</p>

Construction of Antisense MT1-MMP Vector and Its Inhibitory Effects on Invasion of Human Ovarian Cancer Cells / 华中科技大学学报（医学）（英德文版）

Membrane-type 1 matrix metalloproteinase (MT1 MMP/MMP 14) plays crucial roles in tumor cell growth, invasion, and angiogenesis. To clarify whether the endogenously expressed MT1-MMP in metastatic human ovarian carcinoma cell lines SKOV3 plays a critical role in tumor cell invasiveness, antisense MT1-MMP cloned in eukaryotic expression vector pMMP14as was transferred into SKOV3 cells. 48h after transfection, decreased expression of endogenous MT1-MMP protein was detected in pMMP14as transfected SKOV3 cells and the activation of pro MMP2was inhibited markedly. The mean percentage of invasive cells was (62. 50 ±5. 30) % in pMMP14as-transfected cells, which was obviously less than that (97.20±6.90) % in the control.Thus, antisense MT1 MMP effectively inhibited the endogenous MT1 MMP expression and the invasiveness in SKOV3 cells, suggesting that MT1-MMP may be a therapeutic target molecule for human invasive ovarian cancers.

Recombinant adenovirus vector-mediated herpes simplex virus thymidine kinase gene transfer followed by ganiciclovir administration effectively inhibits growth of human small-cell lung cancer in a murine xenotransplant model / 中华肿瘤杂志

<p><b>OBJECTIVE</b>Adenovirus vector-mediated herpes simplex virus thymidine kinase gene (ADV-TK) transfer in combination with ganiciclovir (GCV) is one of the major gene therapy strategies to eradicate tumor cells. This study was aimed at determining the in vivo anti-tumor efficacy of ADV-TK in combination with ganiciclovir (GCV).</p><p><b>METHODS</b>A murine xenotransplant model of human small-cell lung cancer was established. ADV-TK was administrated by intra-tumoral injection followed by intraperitoneal administration of GCV. The anti-tumor efficacy was evaluated using index of tumor volume, relative tumor volume, tumor weight, relative tumor proliferative rate, and tumor growth curve.</p><p><b>RESULTS</b>In the presence of GCV, ADV-TK effectively inhibited growth of human small-cell lung cancer in a dose-dependent fashion. An inhibition plateau was not observed within the current dosage range. ADV-TK at a dose of 6.0 x 10(9) viral particles/kg in the presence of GCV lead to 64.6% and 81.7% inhibition of tumor growth respectively in two independent experiments. ADV-TK or GCV alone caused slight inhibition of tumor growth, which was not statistically significant as compared to the negative control group (P > 0.05).</p><p><b>CONCLUSION</b>ADV-TK followed by GCV is highly efficacious to inhibit the growth of human small-cell lung cancer in a murine xenotransplant model. The results presented here are encouraging to warrant a further clinical evaluation of the potential therapeutic benefits of this strategy.</p>

The mechanism of topotecan resistance in ovarian cancer cell line / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To study the mechanism of topotecan (TPT) resistance in ovarian cancer cell line.</p><p><b>METHODS</b>A TPT-resistant ovarian cancer cell line A2780/TPT established in this laboratory was used in this study. Intracellular rhodamine fluorescence intensity of the TPT-resistant cells and parental cells were measured by flow cytometry. The gene expression of membrane protein transporter such as transporter P-glycoprotein (P-gp), multidrug resistance associated protein (MRP), breast cancer resistance protein (BCRP) was evaluated by RT-PCR. The antisense-phosphorothioate oligonucleotide (ASODN) including a translation initiation site of BCRP mRNA was transferred into resistant cells by liposome.</p><p><b>RESULTS</b>Intracellular rhodamine fluorescence intensity of the resistant cells was 31.19% of that in the parental cells (P < 0.01). No expression of P-gp was demonstrated, and that of MRP was very weak in the TPT-resistant cells (relative expression value = 0.057). BCRP was overexpressed in the TPT-resistant cells (relative expression = 0.66), but not in the parental cells. Transfer of ASODN into resistant cells resulted in a 59.42% reduction of BCRP gene expression (P < 0.05) and an obviously increased intracellular rhodamine fluorescence intensity from 5.42 to 16.63 (P < 0.05).</p><p><b>CONCLUSION</b>The overexpression of BCRP which mediated drug efflux may play an important role in the induction of TPT-resistance in ovarian cancer.</p>

Correlation of expression of RhoA (RhoC and their effector ROCK-1 with malignant phenotype of ovarian cancer cells in vitro / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To investigate the expression of RhoA, RhoC and their effector ROCK-1 in four ovarian cancer cell lines in vitro and their correlation with invasiveness.</p><p><b>METHODS</b>Expression of RhoA, RhoC and ROCK-1 mRNA and protein in four ovarian cancer cell lines SW626, Skov-3, A2780 and Caov-3 was detected by RT-PCR and Western blot assay. Invasion assay was done in Boyden chamber.</p><p><b>RESULTS</b>The expression levels of RhoA, RhoC and ROCK-1 mRNA and protein varied in the four different cell lines examined. The expression level of RhoC, but not RhoA and ROCK-1, was significantly correlated with the invasive capability of these cells in vitro (r = 0.95, P < 0.01). Expression of RhoA at the level of transcription was not correlated with that at the translation level. The expression of RhoA and RhoC did not correlate with that of ROCK-1.</p><p><b>CONCLUSION</b>Expression level of RhoC may serve as an independent parameter in evaluating metastasis and become a new target in inhibiting ovarian cancer metastasis.</p>

Selective apoptosis in HeLa cells induced by sodium butyrate and its mechanism / 中国医学科学院学报

<p><b>OBJECTIVE</b>To investigate apoptosis induced by sodium butyrate in cervix cancer cell line HeLa and primary human embryo lung fibroblasts and its mechanism.</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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.</p><p><b>CONCLUSION</b>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.</p>

Significance of expression of T lymphoma invasion/metastasis gene in ovarian cancer cells / 中国医学科学院学报

<p><b>OBJECTIVE</b>To study the role of T lymphoma invasion/metastasis gene 1 (Tiam1) and protein in ovarian tumor cells.</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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).</p><p><b>CONCLUSION</b>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.</p>

Mdr-1 ribozyme in the reversal of multidrug resistance in human ovarian cancer / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To study the mechanism of multidrug resistance and its reversal by mdr-1 ribozyme in human ovarian cancer.</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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.</p><p><b>CONCLUSION</b>Multidrug resistance of A2780/ADM, possibly being caused by overexpression of mdr-1 gene, can be partially reversed by mdr-1 ribozyme.</p>

A new method for construction of EGFP-labled recombinant adenovirus containing hVEGF(165) and its property in vitro / 中国实验血液学杂志

By using AdEasy system, which is based on the homologous recombination in bacteria, an EGFP labled recombinant adenovirus vector containing hVEGF(165) was generated quickly and its property was studied in vitro. First, hVEGF(165) coding sequence was subcloned into the shuttle plasmid pAdTrack-CMV, then linearized and cotransferred with adenoviral backbone vector pAdEasy-1 into E. coli strain BJ(5183). After positive kanamycin-resistant colony was picked up, the recombinant adenoviral plasmid was identified by restriction analysis with PacI and transfected into HEK 293 cells to assembly replication-defective adenovirus Ad-EGFP/hVEGF(165). The further amplified recombinant adenoviruses were purified by CsCl banding at 32,000 rpm for 18 to 24 hours. Electron microscopy and PCR were performed for testing the recombinant adenovirus. The results showed that the purified particles were homogenous hexagon with a high titer up to 2 x 10(12)pfu/ml. An amplified band of 540 bp fragment demonstrated the successful insert of hVEGF(165). Under fluorescence microscopy, the expression of EGFP was easily detected in HEK 293 and other target cells. The maximal stimulating effect on the proliferation of hUVEC was obtained when the given multiplicity of infection (MOI) of Ad-EGFP/hVEGF(165) was 100. The rate of EGFP positive mouse bone marrow mononuclear cells analysed by flow cytometry was 27.3% after 24 hour-incubation with Ad-EGFP/hVEGF(165) (MOI = 100), and the expression of hVEGF(165) protein in the conditioned medium was 1385 +/- 332 pg/10(6) cells. It is concluded that the construction of adenovirus vector by homologous recombination in bacteria using AdEasy system can be quickly and easily performed, and the prepared high titer of Ad-EGFP/hVEGF(165) is an efficient helpful vector to transfer genes into target cells, all of which make the further in vivo experiments with VEGF(165) possible.

Reversal of drug resistance in human ovarian cancer cells by wild-type PTEN gene and its mechanisms / 中华妇产科杂志

Objective To examine expression of PTEN gene in ovarian cancer cisplatin-sensitive cell line OV2008 cells and cisplatin-resistant cell line C13K cells,and evaluate the effect of wild-type PTEN gene on reversing cisplatin-resistance of C13K cells and underlying mechanisms.Methods The expression of PTEN mRNA and protein in OV2008 and C13K cells were detected by semi-quantitative RT-PCR and western blot.Recombinant eukaryotic expression plasmid containing human wild-type PTEN gene was transfected into C13K cells by lipofectamine 2000.The expression of PTEN mRNA was monitored by RT- PCR and the expression of PTEN,protein kinase B(AKT),phospho-AKT(p-AKT)protein were analyzed by western blot in PTEN transfected and untransfected C13K cells.Proliferation and chemosensitivity of cells to cisplatin were measured by methyl thiazolyl tetrazolium(MTT),and cell apoptosis was detected by flow cytometry after treatment with cisplatin.Results(1)The expression of PTEN mRNA and protein(1.02 ?0.05,1.02?0.07)in OV2008 cells were significantly higher than those in C13K cells,which were 0.45 ?0.03 and 0.55?0.03 respectively(P