A Novel Nitrobenzoate Microtubule Inhibitor that Overcomes Multidrug Resistance Exhibits Antitumor Activity.

Multidrug resistance is a major limitation for microtubule-binding agents in cancer treatment. Here we report a novel microtubule inhibitor (2-morpholin-4-yl-5-nitro-benzoic acid 4-methylsulfanyl-benzyl ester, IMB5046), its cytotoxicity against multidrug-resistant cell lines and its antitumor efficacy in animal models. IMB5046 disrupted microtubule structures in cells and inhibited purified tubulin polymerization in vitro. It bound to the colchicine pocket of tubulin. IMB5046 displayed potent cytotoxicity against multiple tumor cell lines with an IC50 range of 0.037-0.426 µM. Notably, several multidrug-resistant cell lines which were resistant to colchicine, vincristine and paclitaxel remained sensitive to IMB5046. IMB5046 was not a P-glycoprotein substrate. IMB5046 blocked cell cycle at G2/M phase and induced cell apoptosis. Microarray assay indicated that the differentially expressed genes after IMB5046 treatment were highly related to immune system, cell death and cancer. In a mouse xenograft model IMB5046 inhibited the growth of human lung tumor xenograft by 83% at a well-tolerated dose. It is concluded that IMB5046 is a tubulin polymerization inhibitor with novel chemical structure and can overcome multidrug resistance. It is a promising lead compound for cancer chemotherapy, especially for treatment of multidrug-resistant tumors.

A multifunctional drug combination shows highly potent therapeutic efficacy against human cancer xenografts in athymic mice.

The tumor microenvironment plays a crucial role during tumor development. Integrated combination of drugs that target tumor microenvironment is a promising approach to anticancer therapy. Here, we report a multifunctional combination of low-cytotoxic drugs composed of dipyridamole, bestatin and dexamethasone (DBDx) which mainly acts on the tumor microenvironment shows highly potent antitumor efficacy in vivo. In mouse hepatoma H22 model, the triple drug combination showed synergistic and highly potent antitumor efficacy. The combination indices of various combinations of the triple drugs were between 0.2 and 0.5. DBDx inhibited the growth of a panel of human tumor xenografts and showed no obvious systemic toxicity. At tolerated doses, DBDx suppressed the growth of human hepatocellular carcinoma BEL-7402, HepG2, and lung adenocarcinoma A549 xenografts by 94.5%, 93.7% and 96.9%, respectively. Clonogenic assay demonstrated that DBDx showed weak cytotoxicity. Western blot showed that Flk1 and Nos3 were down-regulated in the DBDx-treated group. Proteomic analysis showed that DBDx mainly affected the metabolic process and immune system process; in addition, the angiogenesis and VEGF signaling pathway were also affected. Conclusively, DBDx, a multifunctional drug combination of three low-cytotoxic drugs, shows synergistic and highly potent antitumor efficacy evidently mediated by the modulation of tumor microenvironment. Based on its low-cytotoxic attributes and its broad-spectrum antitumor therapeutic efficacy, this multifunctional combination might be useful in the treatment of cancers, especially those refractory to conventional chemotherapeutics.

[A random control study of indomethacin-containing MYCu intrauterine contraceptive device for 60 months].

OBJECTIVE: To explore the clinical efficacy and safety of MYCu intrauterine contraceptive device (IUD) containing indomethacin. METHODS: From October 1 to December 31, 2004, women of child-bearing age requiring IUD for contraception were chosen from the Outpatient Departments of China-Japan Friendship Hospital of Jilin University, Peking University First Hospital, Peking University Third Hospital, Jilin University Second Hospital and Affiliated Shengjing Hospital of China Medical University. They were randomly inserted with MYCuIUD and control TCu380A IUD each for 1000 cases and followed up at 1, 3, 6, 12, 24, 36, 48 and 60 months post-insertion. RESULTS: When MYCu IUD group and TCu380A group 60 months post-insertion were compared, the cumulative pregnancy rates with IUD in situ were 2.38/100 women per year and 2.84/100 women per year respectively. And the difference had no statistical significance (P > 0.05); the cumulative expulsion rates, mostly of partial expulsion and downward movement, were 0.87/100 women per year and 2.94/100 women per year respectively. And the difference had statistical significance (P < 0.05); the cumulative termination rates due to bleeding/pain were 3.57/100 women per year and 4.83/100 women per year respectively. And the difference had no statistical significance (P > 0.05); Side effects in MYCu group were less pronounced than those in TCu group. And the inter-group differences had statistical significance (P < 0.05). CONCLUSION: As a comparatively ideal medicated medical device, MYCu IUD has an excellent contraceptive efficacy, a low rate of expulsion and side effects and good reversibility. Particularly a low occurrence rate of bleeding and pain during early insertion is recommended. Its life expectancy is 15 years. And its contraceptive effectiveness and safety after 5 years should be examined during further follow-ups.

[Interaction mechanism and influence between fatty acid oxidation in trophoblast cells and p38MAPK signal transduction pathway of severe preeclampsia].

OBJECTIVE: To investigate the effects of expression of mitochondria long-chain fatty acid oxidative enzyme (long-chain 3 hyroxyacyl CoA dehydrogenase, LCHAD) and p38 mitogen activated protein kinase (p38MAPK) signal transduction pathway in severe preeclampsia. METHODS: Serum-free trophoblast cells cultured in vitro were stimulated by early onset severe preeclampsia serum (E-PE group), late onset severe preeclampsia serum (L-PE group), HELLP syndrome serum (HELLP group), and normal pregnancy serum (NP group) respectively; each group was added DMEM/F12 medium, reduced form of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase inhibitor (NADPH-I) and p38MAPK inhibitor (p38-I) to stimulate cells. Expression of mRNA and protein of LCHAD in trophoblast cells were detected by real-time PCR and western blot. RESULTS: (1)The expression of mRNA of LCHAD: the level of mRNA of LCHAD in NP+DMEM, E-PE+DMEM, E-PE+NADPH-I, E-PE+p38-I, L-PE+DMEM, L-PE+NADPH-I, L-PE+p38-I and HELLP+DMEM, HELLP+NADPH-I, HELLP+p38-I groups were 1.00 ± 0.03, 0.14 ± 0.08, 0.95 ± 0.20, 1.43 ± 1.02, 0.37 ± 0.18, 1.51 ± 0.36, 1.60 ± 0.31, 0.10 ± 0.04, 0.49 ± 0.10, 0.44 ± 0.21, respectively. The relative expressions of mRNA of LCHAD were significantly reduced in E-PE+DMEM, L-PE+DMEM and HELLP+DMEM groups compared with the NP+DMEM group (P < 0.05). Compared with the NP groups, the relative expressions of mRNA of LCHAD were significantly increased in L-PE+NADPH-I and L-PE+p38-I group (P < 0.05), while reduced in HELLP groups(P < 0.05). (2) The expression of protein of LCHAD: the relative expressions of protein of LCHAD in NP+DMEM, E-PE+DMEM, E-PE+NADPH-I, E-PE+p38-I, L-PE+DMEM, L-PE+NADPH-I, L-PE+p38-I and HELLP+ DMEM, HELLP+NADPH-I, HELLP+p38-I groups were 19.4 ± 2.2, 10.7 ± 1.1, 17.9 ± 3.3, 19.1 ± 2.9, 16.4 ± 2.3, 20.3 ± 2.3, 20.9 ± 4.3, 12.4 ± 2.3, 17.6 ± 2.6, 17.7 ± 2.0 respectively. Compared with the NP groups, the protein expressions of LCHAD were significantly remarkably reduced in E-PE+DMEM, L-PE+DMEM and HELLP groups (P < 0.05). Compared with the DMEM groups, the protein expressions of LCHAD were significantly increased in NADPH-I and p38-I groups of E-PE, L-PE and HELLP groups (P < 0.05). CONCLUSIONS: These studies demonstrate that long chain fatty acid oxidation was involved in the pathogenesis and development of preeclampsia. The expressions of gene and protein of LCHAD were remarkably affected by early onset severe preeclampsia and HELLP syndrome. NADPH-I and p38-I may allay the disorder of fatty acid oxidation. p38MAPK signal transduction pathway may contributed in this process.

[Interaction mechanism and influence between fatty acid oxidation and p38MAPK signal transduction pathway in trophoblast cells incubated with fatty acids].

OBJECTIVE: To explore the interaction mechanism and influence between fatty acids oxidation and p38MAPK signal transduction pathway in trophoblast cells stimulated by fatty acids of different chain lengths. METHODS: Serum-free trophoblast cells cultured in vitro were divided into 5 groups, i.e. incubation with DMEM/F12 medium without FFA (F-FFA), short-chain fatty acids (SC-FFA), medium-chain fatty acids (MC-FFA), long-chain fatty acids (LC-FFA) and very long-chain fatty acids (VLC-FFA). Then cells in each group were stimulated by DMEM/F12 medium, NADPH oxidase inhibitor (Apocynin) and p38MAPK inhibitor (SB203580) and were subdivided into FFA plus-DMEM group, plus-NADPH-I and plus-p38MAPK-I groups. Expressions of mRNA and protein of LCHAD in trophoblast cells were detected by real-time polymerase chain reaction (PCR) and Western blot. RESULTS: (1) mRNA expression of LCHAD: the Δct of mRNA of LCHAD in F-FFA+DMED, SC-FFA+DMEM, MC-FFA+DMEM, LC-FFA+DMEM, LC-FFA+NADPH-I, LC-FFA+p38MAPK-I and VLC-FFA+DMEM, VLC-FFA+NADPH-I, VLC-FFA+p38MAPK-I groups were 4.57 ± 0.12, 4.36 ± 0.09, 4.55 ± 0.10, 6.84 ± 0.42, 4.45 ± 0.24, 5.08 ± 0.36, 2.23 ± 0.15, 3.90 ± 0.32, 3.81 ± 0.41. Compared with the F-FFA groups, the relative mRNA expressions of LCHAD significantly decreased in LC-FFA+DMEM/p38MAPK-I groups (P < 0.05) while increased in VLC-FFA groups (P < 0.05). Compared with the LC-FFA+DMEM groups, the relative mRNA expressions of LCHAD increased in LC-FFA+NADPH-I/p38MAPK-I groups (P < 0.05). The relative mRNA expressions of LCHAD in VLC-FFA+NADPH-I/p38MAPK-I groups significantly decreased versus VLC-FFA+DMEM group (P < 0.05). (2) Protein expression of LCHAD: The relative protein expressions of LCHAD in F-FFA+DMED, SC-FFA+DMEM, MC-FFA+DMEM, LC-FFA+DMEM, LC-FFA+NADPH-I, LC-FFA+p38MAPK-I and VLC-FFA+DMEM, VLC-FFA+NADPH-I, VLC-FFA+p38MAPK-I groups were 23.6 ± 13.0, 21.2 ± 10.2, 19.7 ± 1.9, 10.6 ± 2.6, 14.0 ± 1.8, 14.0 ± 2.8, 29.3 ± 1.9, 35.8 ± 3.2 and 35.2 ± 4.5 respectively. Compared with the F-FFA groups, the protein expressions of LCHAD significantly decreased in LC-FFA groups (P < 0.05) while increased in VLC-FFA+NADPH-I/p38MAPK-I groups (P < 0.05). CONCLUSION: Free fatty acids affect the gene and protein expressions of mitochondrial ß-oxidation enzyme of LCHAD in trophoblastic cells. Fatty acid ß-oxidation is impaired in trophoblast cells incubated with long-chain fatty acid. NADPH oxidase and p38MAPK inhibitors may alleviate such an effect. Thus p38MAPK signal transduction pathway may participate in this process. The correlation between very long chain fatty acids and fatty acid ß-oxidation is confirmed. But their interactions require further explorations.

[Effects of expression of mitochondria long-chain fatty acid oxidative enzyme with different chain lengths of free fatty acids in trophoblast cells].

OBJECTIVE: To explore the interacting mechanisms and influences of different chain lengths of fatty acids and the expression of mitochondria long-chain 3 hydroxyacyl CoA dehydrogenase (LCHAD) in trophoblast cells. METHODS: The serum-free trophoblast cells cultured in vitro were divided into 5 groups to receive the stimulations of DMEM/F12 medium without FFA (F-FFA), short-chain fatty acids (SC-FFA), medium-chain fatty acids (MC-FFA), long-chain fatty acids (LC-FFA), very long-chain fatty acids (VLC-FFA). The expressions of mRNA and protein of LCHAD in trophoblast cells were detected by real-time polymerase chain reaction (PCR) and Western blot. RESULTS: Compared with the F-FFA, SC-FFA and MC-FFA groups, the expressions of gene and protein of LCHAD significantly decreased (P < 0.05) in the LC-FFA group. The expression of gene of LCHAD increased significantly in the VLC-FFA group (P < 0.05). But no difference existed in protein expression between the VLC-FFA group and other three groups (P > 0.05). Gene expression of LCHAD had no difference among the F-FFA, SC-FFA, MC-FFA groups (P > 0.05). Compared with the LC-FFA group, the expression of gene of LCHAD increased significantly in the VLC-FFA group (P < 0.05). CONCLUSION: Free fatty acids may affect the expression of mitochondrial ß-oxidation enzyme of LCHAD in trophoblast cells. Long-chain fatty acid alters the LCHAD gene protein expression. The correlation between very long chain fatty acids and the gene expression of LCHAD has been detected and their interactions needs further explorations. Short or medium chain fatty acids have no significant effect on the mitochondrial metabolism of fatty acid ß-oxidation in trophoblast cells.

A cell penetrating peptide-integrated and enediyne-energized fusion protein shows potent antitumor activity.

Arginine-rich peptides belong to a subclass of cell penetrating peptides that are taken up by living cells and can be detected freely diffusing inside the cytoplasm and nucleoplasm. This phenomenon has been attributed to either an endocytotic mode of uptake and a subsequent release from vesicles or a direct membrane penetration. Lidamycin is an antitumor antibiotic, which consists of an active enediyne chromophore (AE) and a noncovalently bound apoprotein (LDP). In the present study, a fusion protein (Arg)(9)-LDP composed of cell penetrating peptide (Arg)(9) and LDP was prepared by DNA recombination, and the enediyne-energized fusion protein (Arg)(9)-LDP-AE was prepared by molecular reconstitution. The data in fixed cells demonstrated that (Arg)(9)-LDP could rapidly enter cells, and the results based on fluorescence activated cell sorting indicated that the major route for (Arg)(9)-mediated cellular uptake of protein molecules was endocytosis. (Arg)(9)-LDP-AE demonstrated more potent cytotoxicity against different carcinoma cell lines than lidamycin in vitro. In the mouse hepatoma 22 model, (Arg)(9)-LDP-AE (0.3mg/kg) suppressed the tumor growth by 89.2%, whereas lidamycin (0.05 mg/kg) by 74.6%. Furthermore, in the glioma U87 xenograft model in nude mice, (Arg)(9)-LDP-AE at 0.2mg/kg suppressed tumor growth by 88.8%, compared with that of lidamycin by 62.9% at 0.05 mg/kg. No obvious toxic effects were observed in all groups during treatments. The results showed that energized fusion protein (Arg)(9)-LDP-AE was more effective than lidamycin and would be a promising candidate for glioma therapy. In addition, this approach to manufacturing fusion proteins might serve as a technology platform for the development of new cell penetrating peptides-based drugs.

[Correlation between severe preeclampsia and abnormal expression of long-chain fatty acid oxidative enzyme].

OBJECTIVE: To explore the correlation between severe preeclampsia and abnormal expression of long-chain 3-hydroxyacyl-CoA dehydrogenase (LCHAD). METHODS: Serum-free trophoblast cells cultured in vitro were divided into 4 groups under the stimulations of normal pregnancy serum (NP group), early onset severe preeclampsia serum (E-PE group), late onset severe preeclampsia serum (L-PE group) and HELLP (hemolysis, elevated liver enzymes & low platelets) syndrome serum (HELLP group) respectively. The expressions of mRNA and protein of LCHAD in trophoblast cells were detected by real-time polymerase chain reaction (PCR) and Western blot. RESULT: (1) Expression of LCHAD mRNA: the relative expressions of mRNA of LCHAD in NP, E-PE, L-PE and HELLP groups were 1.00 ± 0.00, 3.08 ± 0.22, 1.62 ± 0.23 and 3.36 ± 0.18 respectively. The relative expressions of LCHAD mRNA were significantly reduced in the E-PE, L-PE and HELLP groups versus the NP group (P < 0.05). Compared with the L-PE group, the gene expressions of LCHAD significantly decreased in the E-PE and HELLP groups (P < 0.05) while no significant difference was found between the E-PE and HELLP groups (P > 0.05). (2) Expression of LCHAD protein: the relative expressions of LCHAD protein were 4.94 ± 0.02, 2.93 ± 0.13, 4.14 ± 0.06 and 2.80 ± 0.09 in the NP, E-PE, L-PE and HELLP groups respectively. The protein expressions of LCHAD were remarkably reduced in the E-PE, L-PE and HELLP groups versus the NP group (P < 0.05). The expressions of LCHAD protein remarkably decreased in the E-PE and HELLP groups versus the L-PE group (P < 0.05) while no significant difference was found between the E-PE and HELLP groups (P > 0.05). CONCLUSION: Long chain fatty acid oxidation is involved in the pathogenesis and development of preeclampsia. The expressions of LCHAD gene and protein are remarkably affected by early onset severe preeclampsia and HELLP syndrome. The interacting mechanism and influence between fatty acid oxidation and the development of preeclampsia are worth further exploring.

Endostar, a modified recombinant human endostatin, exhibits synergistic effects with dexamethasone on angiogenesis and hepatoma growth.

We evaluated the efficacy of a combination strategy, Endostar, a modified recombinant human endostatin, plus dexamethasone, against angiogenesis and hepatoma growth. By colony formation assay, synergistic effects of the combination of Endostar and dexamethasone were observed on the proliferations of human umbilical endothelial cells and hepatoma Bel-7402 cells. Endostar plus dexamethasone inhibited angiogenesis events in vitro. Examined with transwell assay, HUVECs invasion was more efficiently suppressed by combination of Endostar and dexamethasone than by the respective single drug. But the combination treatment of Endostar and dexamethasone to Bel-7402 cells did not alter the migration of HUVECs. The migration of HUVEC tended to coincident with VEGF secretion as determined by ELISA. Tube formation assay, rat aortic ring assay and chick embryo chorioallantoic membrane (CAM) assay indicated that the anti-angiogenesis effects of Endostar were significantly enhanced by dexamethasone. In mouse hepatoma H22 and human hepatoma Bel-7402 subcutaneous xenograft, Endostar plus dexamethasone presented more potent efficacy in tumor growth suppression than the single drug treatments. The above confirms the synergism of Endostar and dexamethasone on anti-angiogenesis and suppression of hepatoma growth. The potentiation effects of the combination indicate that Endostar plus dexamethasone might be a positive strategy for cancer therapy.

[Efficacy and safety of drospirenone-ethinylestradiol on contraception in healthy Chinese women: a multicenter randomized controlled trial].

OBJECTIVE: To evaluate the contraception efficacy, mode of bleeding, side effects and other positive effects of drospirenone-ethinylestradiol (Yasmin) in healthy Chinese women. METHODS: This was a multicenter, randomized, control study of 768 healthy Chinese women who consulted about contraception. The subjects were randomized into Yasmin group (30 microg ethinylestradiol plus 3 mg drospirenone, 573 cases) or desogestrel group (30 microg ethinylestradiol plus 150 microg desogestrel, 195 cases) with the ratio of 3:1. Each individual was treated for 13 cycles. Further visits were required at cycle 4, cycle 7, cycle 10 and cycle 13 of treatment Weight, height, body mass index were evaluated at each visit. The menstrual distress questionnaire (MDQ) was given to the women at baseline, visit 3 (cycle 7) and visit 5 (after cycle 13). RESULTS: The values of basal features were similar between two groups (P > 0.05). The Pearl index (method failure) of Yasmin was 0. 208/hundred women year which was lower than that of desogestrel (0. 601/hundred women year). The mode of bleeding was similar between two groups after trial without showing any significant difference. According to MDQ subscale, the improvement of water retention and increasing appetite during inter-menstrual period and water retention and general well-being during menstrual period in the Yasmin group (-0.297, -0.057, 0.033, 0.150 respectively) was more obvious than that in the desogestrel group (-0.108, 0.023, 0.231, -0.023 respectively) with a significant difference (P < 0.05). Some other values which improved in both two groups, especially the improvement of breast tenderness and pain and skin abnormality in Yasmin group (18.0%, 89/494; 12.6%, 62/494) was more distinct than that in desogestrel group (11.3%, 19/168; 5.4%, 9/168). The mean weight increased in desogestrel group (0.57 kg) while it decreased in Yasmin group (-0.28 kg) with a significant difference (P < 0.01). CONCLUSIONS: Both Yasmin and desogestrel have good efficacy on contraception and similar modes of menstrual bleeding. Yasmin is better than desogestrel in terms of weight control and premenstrual syndrome of oral contraceptive.

Synergy of gemcitabine and lidamycin associated with NF-kappaB downregulation in pancreatic carcinoma cells.

AIM: To investigate the effects on human pancreatic cancer PANC-1 and SW1990 cells using a combination of lidamycin (LDM) and gemcitabine. METHODS: A 3- (4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay was used to determine the growth inhibition of drugs in PANC-1 and SW1990 cells. The effects on apoptosis were measured by terminal uridine deoxynucleotidyl transferase dUTP nick end labeling assay and flow cytometry combined with fluorescein- isothiocyanate-Annexin V/propidium iodide staining. The activity of caspase-3 was measured with a special assay kit. The mitochondrial membrane potential was determined by confocal microscopy analyses. The level of mRNA encoding K-ras in the cells was determined by RT-PCR analysis. The expression of K-ras, NF-kappaB, and Bcl-2 was detected by Western blotting analysis. RESULTS: There was a significant reduction in proliferation in the pancreatic cancer cell lines treated with a combination of gemcitabine and LDM. The overall growth inhibition directly correlated with apoptotic cell death. LDM potentiated the gemcitabine-induced cell killing by reducing mitochondrial membrane potential and increasing the caspase-3 activity. Notably, the K-ras mRNA level was significantly reduced with the combination of gemcitabine and LDM. The results for K-ras, NF-kappaB, and Bcl-2 proteins also showed downregulation in the combination group relative to the single-agent treatment and the untreated control. CONCLUSION: LDM can potentiate the growth inhibition induced by gemcitabine in human pancreatic cancer cells, and the synergy may be associated with NF-kappaB downregulation.

[Genetic advances in hydatidiform mole].

Hydatidiform mole is the most common gestational trophoblastic disease and is characterized by gross trophoblastic hyperplasia resulting from abnormal fertilization of the oocyte. It is of great interest to researchers because of its propensity for local invasion and spreading. Using cytogenetic and molecular genetic techniques researchers have performed various studies on hydatidiform mole. There are advances in the understanding of karyotype, DNA ploidy, fertilization types, expression of imprinted genes, the differences between genetic classification and pathologic classification, and the correlation to its invasion and spreading.

Distribution of the alleles at loci D16S539, D7S820, and D13S317 in hydatidiform mole genome from Chinese women and its relationship with clinical prognosis.

Using polymerase chain reaction and denaturating polyacrylamide gel electrophoretic techniques, we studied 53 cases of hydatidiform moles. Of these, 41 cases were genetically complete hydatidiform moles (g-CHM) whose genome were totally paternally derived. We investigated the distribution of the alleles in the short tandem repeat sequences at loci D16S539, D7S820, and D13S317 in these cases. In particular, we analyzed the allelic distribution and potential significance in cases with traceable benign and invasive moles (i.e., persistent trophoblastic tumor [PTT]). Among 41 g-CHM cases, there were six alleles at D16S539, five alleles at D7S820 (the frequencies of alleles 9 and 10 were respectively lower and higher than those in Beijing population), and seven alleles at D13S317; the heterozygosity of loci D16S539, D7S820, and D13S317 was 0.0732, 0.0976, and 0.0732, respectively. Among 23 benign cases, there were six alleles at D16S539, four at D7S820, and six at D13S317; among 11 PTT cases, there were five alleles at D7S820 and four alleles each at D16S539 and D13S317. The frequencies of allele 9 at D16S539 and allele 10 at D7S820 were higher than in benign cases (P < 0.05). There were significant differences in frequencies of alleles 9 and 10 at D7S820 between the cases and the Beijing population, and heterozygosity at the three loci was lower in the cases than in the population. In addition, invasiveness of hydatidiform mole correlated to the frequency of allele 9 at loci D16S539 and allele 10 at D7S820.

[Chemosensitivity of mdr1 gene overexpressed multidrug resistant cancer cells to lidamycin].

AIM: To investigate the chemosensitivity to lidamycin (C-1027) in mdr1 gene overexpressing cancer cell lines established by drug induction and by gene-transfection. METHODS: DNA was cloned by RT-PCR and then eukaryotic expressing recombinant plasmid pcDNA3. 1/mdrl was constructed. Using Lipofectamine 2000, a strain of stably transfected human hepatoma cancer cells, HepG2/mdrl, was obtained. The mdr1 mRNA level, P-glycoprotein (P-gp) level and the activity of P-gp to extrude drugs in cancer cells were determined by RT-PCR, immunofluorescence analysis and rhodamine 123 efflux assay. The chemosensitivity of cancer cells with low or high mdr1 expression to lidamycin and other antitumor drugs was tested by MTT assay. RESULTS: The mdr1 mRNA and P-gp levels in KBv200, MCF-7/ADR, and stably transfected HepG2/mdr1 cells were much higher than that in respective parent KB, MCF-7 and HepG2 cells. The IC50 values of lidamycin for KBv200, MCF-7/ADR and HepG2/mdrl cells were (0.24 +/- 0.20) nmol x L(-1), (0.028 +/- 0.011) nmol x L(-1), and (0.020 +/- 0.011) nmol x L(-1), respectively. Compared with parental cells, the values of resistant fold for KBv200, MCF-7/ADR and HepG2/mdr1 cells to lidamycin were 6.8, 1.6 and 1.3 fold; to adriamycin were 37.2, 181.3 and 8.8 fold; to taxol were 336.8, 49.2 and 40.3 fold, respectively. CONCLUSION: Lidamycin is highly active to multidrug resistant cancer cells. The chemosensitivity of those resistant cancer cells to lidamycin is approximately at the similar level as that of parent cancer cells.

[Study of gene differential display of hydatidiform moles].

OBJECTIVE: To screen the specific molecular maker of invasive hydatidiform moles (HM) by differential display analysis. METHODS: For dot hybridization, about 1.0 microg of each cDNA sample of invasive and non-invasive HM were labeled as probes using the Dig DNA labeling and Detection Kit (Boehringer Mannheim). The specific expression fragments of invasive HM recovered from PAGE gel were re-amplified by PCR, and the PCR products were dotted onto nylon membrane and hybridized by two probes of invasive and non-invasive HM cDNA respectively. Some fragments with a strong positive hybridization signal were cloned into the polylinker of lasmid PUC19 and were sequenced. The fragments' sequences were searched for homology in the NCBI data using the BLAST (Database: GenBank Human EST entries; Posted date:Aug 31, 2004; Number of letters in database: 1,697,659,032; Number of sequences in database: 3,677,722). RESULTS: The 20 fragments in 28 bands with specific expression in invasive HM were re-amplified, of which 13 showed positive hybridization signals, and 3 were cloned into the polylinker of lasmid PUC19. A fragment in the 3 was a new expressed sequence tag (EST) and the sequence was submitted to NCBI data (dbEST_Id: 10875704; GenBank_Accn: BM403211). CONCLUSION: There are more differences in gene expression between invasive and non-invasive HMs, and differential display analyses are of a potential significance to early diagnosis of invasive HM.

Inhibitory effects of emodin on angiogenesis.

AIM: To determine the anti-angiogenic activity of emodin. METHODS: Chick embryo assay and cultured endothelial cells were used. RESULTS: Emodin at doses of 150 and 300 microg/egg caused 37.6% and 63.2% inhibition of angiogenesis, respectively. Emodin was shown to inhibit the proliferation of primary cultured bovine aortic endothelial cells in the absence or presence of basic-fibroblast growth factor (bFGF) or the presence of vascular endothelial growth factor (VEGF) in a dose-dependent manner. The IC50 values by MTT assay were 5.56, 8.40 or 6.91 mg x L(-1), respectively. Emodin at concentrations from 5.4 to 21.6 mg x L(-1) induced apoptosis of endothelial cells for 37.6% to 72.6%. Emodin caused endothelial cell cycle arrest at G2/M phase. After emodin treatment, there was a down-regulation of Cyclin B1, P34cdc2, and Bcl-2 protein expression while the Bax protein expression was unaffected. CONCLUSION: Emodin shows anti-angiogenic activity and might be useful for the development of novel anti-cancer therapy.

[The relationship between malignant transformation and fertilization types of hydatidiform moles].

OBJECTIVE: To study the relationship between malignant transformation and fertilization types of hydatidiform moles (HM). METHODS: Fifty four HM specimens were analyzed by using multiplex STR-PCR (9 loci) to determine the fertilization types and all patients were followed-up for the human chorionic gonadotropin (hCG) over 1 year. RESULTS: Total malignant transformation cases were 10 in all the 54 HM. Ggenetics complete hydatidiform moles (g-CHM) with DNA from only paternal origin, were observed in 38 cases including 28 homozygote and 10 heterozygote cases. In homozygote and heterozygote cases,malignant transformation occurred in 8 cases of the empty eggs fertilized by single sperms and 2 by double sperms respectively. In all the 54 HMs, 16 cases of DNA from parents were genetic partial hydatidiform moles (g-PHM), and no malignant transformation occurred in each haploidy egg fertilized by double sperms. CONCLUSION: (1)Genetic complete hydatidiform moles (g-CHM) showed a higher malignant transformation risk than genetic partial hydatidiform moles (g-PHM) (P=0.024 2); (2)There was no significant difference in malignant transformation between homozygote and heterozygote of g-CHM (P=0.699).