Biomedical subjects

Xiujie Wang

Publications and source records attributed to Xiujie Wang.

10 recordsLinked to original sources

PubMed2006

Growth inhibition and induction of apoptosis and differentiation of tanshinone IIA in human glioma cells.

Tanshinone IIA is a derivative of phenanthrene-quinone isolated from Danshen, a widely used Chinese herbal medicine. It has antioxidant properties, cytotoxic activities against multiple human cancer cells, inducing apoptosis and differentiation of some human cancer cells. The purpose of this study is to confirm its anticancer activity on human glioma cells, and to elucidate mechanism of its activity. Human glioma cells were tested in vitro for cytotoxicity, colony formation inhibition, BrdU incorporation after treatment with tanshinone IIA. Its effect of apoptosis induction was detected through EB/AO staining, cell cycle analysis and the expressions of ADPRTL1 and CYP1A1 genes, the differentiation induction effect was investigated through morphology, mRNA and protein expressions of GFAP and nestin genes by RT-PCR and immunocytochemistry. Tanshinone IIA demonstrated a dose- and time-dependent inhibitory effect on cell growth, IC(50) was 100 ng/ml, and it significantly inhibited colony formation and BrdU incorporation of human glioma cells. After treatment with 25-100 ng/ml of tanshinone IIA, the apoptotic cells increased significantly (P < 0.01), the cells in G(0)/G(1) phase increased (P < 0.01), and decreased in S phase, ADPRTL1 and CYP1A1 mRNA expression increased 1-2 folds. The cells treated with 100 ng/ml tanshinone IIA demonstrated astrocytes or neuron-like morphology, GFAP mRNA and protein expressions increased, nestin mRNA and protein expressions decreased significantly. The findings in this study suggested that tanshinone IIA exhibited strong effects on growth inhibition and induction of apoptosis and differentiation in human glioma cells. It might serve as a novel promising differentiation-inducing and/or therapeutic agent for human gliomas, and need to be investigated further.

Abietanes↗

PubMed2006

OsWRKY71, a rice transcription factor, is involved in rice defense response.

WRKY proteins are a large family of transcription factors that mainly participate in plant biotic stress responses. So far, one hundred and five OsWRKY genes have been predicted in the rice genome. To identify OsWRKY genes that might function in inducible defense responses, a phylogenetic tree including 184 WRKY proteins from Arabidopsis thaliana, rice, and other species was constructed. Based on the phylogenetic analysis, ten candidate OsWRKY genes that may be involved in defense responses were isolated from salicylic acid (SA)-treated rice seedlings. One of them, OsWRKY71, was up-regulated by several defense signaling molecules, such as SA, methyl jasmonate (MeJA), 1-aminocyclo-propane-1-carboxylic acid (ACC), as well as wounding and pathogen infection, suggesting that OsWRKY71 might function in rice biotic stress response. Transient expression of OsWRKY71:GFP fusion protein in onion epidermis cells revealed that OsWRKY71 was localized in the nucleus. Overexpression of OsWRKY71 gene in rice resulted in enhanced resistance to virulent bacterial pathogens Xanthomonas oryzae pv. oryzae (Xoo) 13751. Furthermore, two marker genes in defense signaling pathway, OsNPR1 and OsPR1b, were constitutively expressed in OsWRKY71-overexpressing transgenic plants. These results suggest that OsWRKY71 might function as a transcriptional regulator upstream of OsNPR1 and OsPR1b in rice defense signaling pathways.

Arabidopsis↗

PubMed2006

Anticancer activity of litchi fruit pericarp extract against human breast cancer in vitro and in vivo.

Litchi fruit pericarp (LFP) extract contains significant amounts of polyphenolic compounds and exhibits powerful antioxidative activity against fat oxidation in vitro. The purpose of this study is to confirm the anticancer activity of LFP extract on human breast cancer in vitro and in vivo, and to elucidate the mechanism of its activity. Human breast cancer cells were tested in vitro for cytotoxicity, colony formation inhibition, BrdU incorporation, and gene expression profiling after treatment with LFP extract. Seven nude mice bearing human breast infiltrating duct carcinoma orthotopically were tested for its anticancer activity and expression of caspase-3 in vivo by oral administration of 0.3% (0.3 mg/ml) of LFP water-soluble crude ethanolic extract (CEE) for 10 weeks. LFP extract demonstrated a dose- and time-dependent inhibitory effect on cell growth (IC(50) = 80 microg/ml), and it significantly inhibited colony formation and BrdU incorporation of human breast cancer cells. Oligonucleotide microarray analysis identified 41(1.22%) up-regulated and 129 (3.84%) down-regulated genes after LFP water-soluble CEE treatment; the predominantly up-regulated genes were involved in various biological functions including cell cycle regulation and cell proliferation, apoptosis, signal transduction and transcriptional regulation, and extracellular matrix/adhesion molecules; and down-regulated genes were mainly associated with adhesion, invasion, and malignancy of cancer cells. A 40.70% tumor mass volume reduction and significant increase of casepase-3 protein expression were observed in vivo experiment. The findings in this study suggested that LFP extract might have potential anticancer activity on both ER positive and negative breast cancers, which could be attributed, in part, to its DNA damage effect, proliferating inhibition and apoptosis induction of cancer cells through up-regulation and down-regulation of multiple genes involved in cell cycle regulation and cell proliferation, apoptosis, signal transduction and transcriptional regulation, motility and invasiveness of cancer cells; ADP-ribosyltransferase (NAD+; poly (ADP-ribose) polymerase)-like 1 (ADPRTL1), Cytochrome P450, subfamily I (CYP1A1) and Hyaluronan-mediated motility receptor (HMMR) might be the main molecular targets at which LFP water-soluble CEE acted.

Animals↗

PubMed2006

Heat shock response and mammal adaptation to high elevation (hypoxia).

The mammal's high elevation (hypoxia) adaptation was studied by using the immunological and the molecular biological methods to understand the significance of Hsp (hypoxia) adaptation in the organic high elevation, through the mammal heat shock response. (1) From high elevation to low elevation (natural hypoxia): Western blot and conventional RT-PCR and real-time fluorescence quota PCR were adopted. Expression difference of heat shock protein of 70 (Hsp70) and natural expression of brain tissue of Hsp70 gene was determined in the cardiac muscle tissue among the different elevation mammals (yak). (2) From low elevation to high elevation (hypoxia induction): The mammals (domestic rabbits) from the low elevation were sent directly to the areas with different high elevations like 2300, 3300 and 5000 m above sea level to be raised for a period of 3 weeks before being slaughtered and the genetic inductive expression of the brain tissue of Hsp70 was determined with RT-PCR. The result indicated that all of the mammals at different elevations possessed their heat shock response gene. Hsp70 of the high elevation mammal rose abruptly under stress and might be induced to come into being by high elevation (hypoxia). The speedy synthesis of Hsp70 in the process of heat shock response is suitable to maintain the cells' normal physiological functions under stress. The Hsp70 has its threshold value. The altitude of 5000 m above sea level is the best condition for the heat shock response, and it starts to reduce when the altitude is over 6000 m above sea level. The Hsp70 production quantity and the cell hypoxia bearing capacity have their direct ratio.

Acclimatization↗

PubMed2005

EUI1, encoding a putative cytochrome P450 monooxygenase, regulates internode elongation by modulating gibberellin responses in rice.

Elongation of rice internodes is one of the most important agronomic traits, which determines the plant height and underlies the grain yield. It has been shown that the elongation of internodes is under genetic control, and various factors are implicated in the process. Here, we report a detailed characterization of an elongated uppermost internode1 (eui1) mutant, which has been used in hybrid rice breeding. In the eui1-2 mutant, the cell lengths in the uppermost internodes are significantly longer than that of wild type and thus give rise to the elongated uppermost internode. It was found that the level of active gibberellin was elevated in the mutant, whereas its growth in response to gibberellin is similar to that of the wild type, suggesting that the higher level accumulation of gibberellin in the eui1 mutant causes the abnormal elongation of the uppermost internode. Consistently, the expression levels of several genes which encode gibberellin biosynthesis enzymes were altered. We cloned the EUI1 gene, which encodes a putative cytochrome P450 monooxygenase, by map-based cloning and found that EUI1 was weakly expressed in most tissues, but preferentially in young panicles. To confirm its function, transgenic experiments with different constructs of EUI1 were conducted. Overexpression of EUI1 gave rise to the gibberellin-deficient-like phenotypes, which could be partially reversed by supplementation with gibberellin. Furthermore, apart from the alteration of expression levels of the gibberellin biosynthesis genes, accumulation of SLR1 protein was found in the overexpressing transgenic plants, indicating that the expression level of EUI1 is implicated in both gibberellin-mediated SLR1 destruction and a feedback regulation in gibberellin biosynthesis. Therefore, we proposed that EUI1 plays a negative role in gibberellin-mediated regulation of cell elongation in the uppermost internode of rice.

Amino Acid Sequence↗

PubMed2005

Potential anticancer activity of litchi fruit pericarp extract against hepatocellular carcinoma in vitro and in vivo.

Litchi fruit pericarp (LFP) extract contains significant amounts of polyphenolic compounds, and exhibits powerful antioxidative activity against fat oxidation in vitro. The purpose of this study is to confirm the anticancer activity of LFP extract against hepatocellular carcinoma in vitro and in vivo, and to elucidate the mechanism of its activity. Human hepatocellular carcinoma cell line was tested in vitro for cytotoxicity, colony formation inhibition, and cell cycle distribution through flow cytometry after treatment with water-soluble crude ethanolic extract (CEE) from LFP. Murine hepatoma bearing-mice were fed doses of 0.15, 0.3, and 0.6g/kg/day of water-soluble CEE in DH(2)O p.o. for 10 days, respectively, to test the anticancer activity and BrdU incorporation of cancer cells in vivo. LFP extract demonstrated a dose- and time-dependent inhibitory effect on cancer cell growth; IC(50) was 80microg/ml, and significantly inhibited colony formation in vitro, tumor growth and BrdU incorporation into cancer cells in vivo. The tumor inhibitory rates at doses of 0.15, 0.3, and 0.6g/kg/day were 17.31% (P>0.05), 30.77% (P<0.05), and 44.23% (P<0.01), respectively. BrdU labeled tumor cells of treated animals were 11.80+/-2.79%, and were significantly lower than that in untreated controls (23.00+/-5.42%, P<0.05). Our findings showed that LFP extract exhibited potential anticancer activity against hepatocellular carcinoma in vitro and in vivo through proliferating inhibition and apoptosis induction of cancer cells.

Animals↗

PubMed2005

Potential anticancer activity of tanshinone IIA against human breast cancer.

Tanshinone IIA is a derivative of phenanthrene-quinone isolated from Danshen, a widely used Chinese herbal medicine. It has antioxidant properties and cytotoxic activity against multiple human cancer cell lines, inducing apoptosis and differentiation of some human cancer cell lines. Our purpose was to confirm its anticancer activity on human breast cancer in vitro and in vivo and to elucidate the mechanism of its activity. Human breast cancer cells were tested in vitro for cytotoxicity, colony formation inhibition, BrdU incorporation and gene expression profiling after treatment with tanshinone IIA. Seven nude mice bearing human breast infiltrating duct carcinoma orthotopically were tested for anticancer activity and expression of caspase-3 in vivo by s.c. injection of tanshinone IIA at a dose of 30 mg/kg 3 times/week for 10 weeks. Tanshinone IIA demonstrated a dose- and time-dependent inhibitory effect on cell growth (IC50 = 0.25 microg/ml), and it significantly inhibited colony formation and BrdU incorporation of human breast cancer cells. Oligonucleotide microarray analysis identified 41 upregulated (1.22%) and 24 downregulated (0.71%) genes after tanshinone IIA treatment. Upregulated genes were involved predominantly in cycle regulation, cell proliferation, apoptosis, signal transduction and transcriptional regulation; and downregulated genes were associated mainly with apoptosis and extracellular matrix/adhesion molecules. A 44.91% tumor mass volume reduction and significant increase of casepase-3 protein expression were observed in vivo. Our findings suggest that tanshinone IIA might have potential anticancer activity on both ER-positive and -negative breast cancers, which could be attributed in part to its inhibition of proliferation and apoptosis induction of cancer cells through upregulation and downregulation of multiple genes involved in cell cycle regulation, cell proliferation, apoptosis, signal transduction, transcriptional regulation, angiogenesis, invasive potential and metastatic potential of cancer cells. ADPRTL1 might be the main target at which tanshinone IIA acted.

Abietanes↗

PubMed2003

Monitoring genome-wide changes in gene expression in response to endogenous cytokinin reveals targets in Arabidopsis thaliana.

Cytokinins have been implicated in developmental and growth processes in plants including cell division, chloroplast biogenesis, shoot meristem initiation and senescence. The regulation of these processes requires changes in cytokinin-responsive gene expression. Here, we induced the expression of a bacterial isopentenyl transferase gene, IPT, in transgenic Arabidopsis thaliana seedlings to study the regulation of genome-wide gene expression in response to endogenous cytokinin. Using MPSS (massively parallel signature sequencing) we identified 823 and 917 genes that were up- and downregulated, respectively, following 24 h of IPT induction. When comparing the response to cytokinin after 6 and 24 h, we identified different clusters of genes showing a similar course of regulation. Our study provides researchers with the opportunity to rapidly assess whether genes of interest are regulated by cytokinins.

Alkyl and Aryl Transferases↗

PubMed2003

[Antitumor effect of gene therapy with recombinant adenovirus-mediated human interleukin-2 gene transfer and its mechanism].

OBJECTIVE: To explore the transfection, expression, antitumor effect and mechanism of a replication-deficient adenovirus vector expressing human IL-2 gene (advhIL-2) in a murine H22 hepatocellular carcinoma model. METHODS: KM mice bearing tumor 100-200 mm3 were injected intratumorally with advhIL-2, adv-LacZ or with PBS alone. The tumor evolution was recorded every 3 days. The transfection and expression of the recombinant adenovirus were examined with X-gal staining and RT-PCR respectively. The splenic LAK and CTL activities were assayed with 51Cr 4 hours release. The infiltration of CD4+ and CD8+ T cells in the tumors were analyzed with immunofluorescence. RESULTS: It was found that the recombinant adenovirus can bring about in vivo effective transfection and expression. The continuosly expressive time of advhIL-2 is longer than 12 days. AdvhIL-2 has dose-dependent anti-tumor effect. The mice received a dose of 2 x 10(9) pfu advhIL-2 divided into halves for two injections developed tumor more slowly and survived much longer than the mice treated with PBS (P < 0.01). Moreover, advhIL-2 increased the splenic LAK and CTL activities, CD4+ and CD8+ T cell infiltration in the H22 tumors significantly. CONCLUSION: Adenovirus-mediated hIL-2 gene treatment has significant antitumor activity in pre-established hepatocellular carcinoma in mice. Antitumor immunity might be responsible for the therapeutic effect.

Adenoviridae↗

PubMed2002

[Nested coamplification polymerase chain reaction].

OBJECTIVE: To develop a simple and reliable method for intensifying the hybridization signals of gene chips. METHODS: The authors added EDTA and another FAM-labeled probe to the normal PCR products, denatured the mixture by heat, and then let the mixture hybridize with the fastened probes on the chip. RESULTS: With the use of EDTA and another FAM-labeled probe, the hybridization signals increased by 6 times or greater. CONCLUSION: Adding EDTA and another probe to the normal PCR products is a simple and efficient method to intensify the hybridization signal of chips.

Base Sequence↗