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Yang Qin

Publications and source records attributed to Yang Qin.

At least 19 recordsLinked to original sources
PubMed2006

Luminescence tuning of organoboron quinolates through substituent variation at the 5-position of the quinolato moiety.

[Structure: see text] A series of organoboron quinolates with emission colors ranging from blue to red have been prepared. In comparison to the respective AlQ3 derivatives a distinct blue-shift of the emission is observed. Theoretical calculations serve to provide insight into the nature of the frontier orbitals and the effect of the substituents in the 5-position of the quinolate ligands on the relative HOMO and LUMO energy levels. An efficient new blue emitting material with a pinacolborane substituent has been identified.

Journal Article↗
PubMed2006

Detection of aberrant promoter methylation of GSTP1 in the tumor and serum of Chinese human primary hepatocellular carcinoma patients.

PURPOSE AND EXPERIMENTAL DESIGN: Glutathione S-transferases, enzymes that prevent cells from damage mediated by oxidant and electrophilic carcinogens, may be early critical determinants of carcinogenesis. To explore the aberrant promoter CpG island methylation of the GSTP1 gene as a biomarker for screening hepatocellular carcinoma (HCC) high risk individuals and for the early detection of HCC, we analyzed its methylation in the tumor and non-tumor tissues and serum samples from 26 patients with HCC, as well as serum from 8 liver cirrhosis patients by methylation-specific PCR (MSP). RESULTS: Twenty-three of 26 (88.5%) tumor tissues and 18 of 26 (69%) corresponding non-tumor tissues displayed GSTP1 promoter CpG island hypermethylation. Similarly, GSTP1 promoter hypermethylation was detected for the first time in 16 of 32 (50%) of circulating tumor DNA in the peripheral serum from HCC patients and 4 of 8 (50%) cirrhosis tissues and 3 of 8 (37.5%) corresponding serum DNA from cirrhosis patients. The aberrant methylation of the GSTP1 gene in the serum of patients is in agreement with tumor methylation status (P = 0.004). None of the 12 normal PBMC samples were methylation positive. CONCLUSIONS: These data indicate that the epigenetic aberrance of promoter CpG island hypermethylation of the GSTP1 gene may contribute to the hepatopathogenesis of HCC and is a potential valuable biomarker for noninvasive disease monitoring and HCC early diagnosis.

Adult↗
PubMed2006

[Construction and expression of protein self-splicing prokaryotic expression vector pTWIN1- AcAPc2].

To express recombinant Ancylostoma caninum anticoagulant peptide-c2 (AcAPc2), a whole cDNA fragment encoding AcAPc2 was achieved by ligation- PCR and inserted into prokaryotic expression vector pTWIN1 for constructing the specific self-splicing prokaryotic expression vector, pTWIN1-AcAPc2; positive recombinants were transformed into E. coli ER2566 for expression research. The recombinant protein, AcAPc2-intein2-CBD, was soluble and expressed in E. coli ER2566 (about 30.1% fusion protein in total protein). AcAPc2-intein2-CBD was characterized to be 41 KD by SDS-PAGE and identified by Western-blot. The recombinant fusion protein was purified to a efficiently high degree by chitin affinity chromatography. After the process of specific self-splicing induced by beta-Mercaptoethanol, the target protein, AcAPc2, was obtained, characterized to be 21 KD by SDS-PAGE and migrated as a dimmer. Molecular weight of AcAPc2 conformed to native dimmer. Bio-information analysis indicated relationship between secondary construction of AcAPc2 and biologic function. These findings greatly facilitate the purification of AcAPc2 and are very important for the additional studies on its anti-coagulation mechanism and its clinical application as anti-coagulation medicine.

Animals↗
PubMed2006

[Construction and expression of prokaryotic expression vector pTWIN1/TRAIL].

OBJECTIVE: To purify an active extracellular region of the TNF related apoptosis inducing ligand (TRAIL) protein. METHODS: According to the high-usage codons in Escherichia coli and the multiple cloning site of expression vector pTWIN1 of a self-splicing prokaryotic expression system, the extracellular region of TRAIL gene was designed and synthesized, which was cloned into pMD18-T vector. After pMD18-T/TRAIL and pTWIN1 were digested by Nru I and EcoR I, the target fragment purified was linked to the expression vector pTWIN1, which was transferred into the competent cell JM109, and positive recombination was screened. After positive recombination vector pTWIN1/TRAIL (identified with restrictive endonuclease digesting and sequencing) was transferred into the ER2566, the expression was induced by different IPTG concentration at different temperature and culture time. The expression products were analyzed by 150 g/L SDS-PAGE. RESULTS: The extracellular region of TRAIL gene was obtained by PCR, and was constructed successfully in a self-splicing prokaryotic expression vector pTWIN1/TRAIL. By 0.3 mmol/L IPTG at 15 degrees C for 14 to 16 hours, the soluble target protein was expressed efficiently. CONCLUSION: High-expression level of the extracellular region of TRAIL fusion protein was attained by use of E. coli ER2566, and the soluble target protein without any additional amino acid was successfully purified by simple treatment.

Cloning, Molecular↗
PubMed2005

In vitro anti-tumor immune response induced by dendritic cells transfected with recombinant adenovirus carrying mutant K-ras genes.

The specific anti-tumor immune response induced by mouse bone marrow dendritic cells (DCs) transfected with recombinant adenovirus carrying mutant k-ras genes was investigated. DCs were generated from mouse bone marrow in the presence of rmGM-CSF (3.3 ng/mL) and rmIL-4 (1.3 ng/mL) and detected by FACS, and then transfected with the recombinant adenovirus encoding mutant k-ras gene. The efficacy of transfection and T cell stimulating activity of DCs were detected. CTL activity of the mice vaccinated with DCs was observed. The results showed that DCs had dendritic veiled morphology. BmDCs highly expressed B7-1 (80%), B7-2 (77%), MHC II (70%), CD11c (65%), CD40 (70%) and CD54 (96%) with FACS, and no significant difference in the expression was observed before and after the transfection (P > 0.05). The DCs transfected by mutant k-ras gene could significantly stimulate lymphocytes proliferation as compared with those transfected by Ad-c or non-modified DCs (P < 0.05). DC vaccine transfected by mutant k-ras gene could induce CTL activity against Lewis lung cancer, but not against B16. The specific cytotoxicity against Lewis lung cancer in Ad-k-ras/12-transduced DC group was significantly higher than those in the control, vector and non-transfected DCs groups (P < 0.05). It was concluded that special antitumor response could be induced by DCs transfected with recombinant adenovirus carrying mutant k-ras genes.

Adenoviridae↗
PubMed2005

[Molecular mechanism of reversing metastatic phenotype in human high-metastatic large cell lung cancer cell line L9981 by nm23-H1].

BACKGROUND & OBJECTIVE: nm23-H1, a tumor metastasis suppressive gene, can reverse tumor metastasis phenotype. But the molecular mechanism of nm23-H1 in inhibiting or reversing metastasis of lung cancer is unclear. This study was to explore the molecular mechanism of nm23-H1 in reversing metastasis phenotype of lung cancer. METHODS: nm23-H1 gene and pLXSN were separately transfected into human lung cancer cell line L9981. Proliferation of L9981, L9981-pLXSN, and L9981-nm23-H1 cells was detected by MTT assay, cell invasive ability was detected by modified Boyden chamber. Tumorigenesis and experimental lung metastasis were determined in vivo. mRNA and protein levels of beta-catenin, E-Cadherin, CD44S, CD44V6, matrix metalloproteinase-2 (MMP-2), tissue inhibitor of metalloproteinase-1 (TIMP-1), and vascular endothelial growth factor (VEGF) were detected by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot. RESULTS: (1)Cell proliferation, clone formation, and invasive ability were significantly lower in L9981-nm23-H1 cells than in L9981 cells [(19.5+/-2.9)% vs. 100%, 10.3+/-0.7 vs. 21.7+/-1.3, 31.0+/-3.0 vs. 151.0+/-6.3, P<0.01]. (2) The inhibitory rate of tumorigenesis of nude mice was significantly higher in L8891-nm23-H1 group than in L9981 group (85.6% vs. 0%, P<0.001)u the lung metastatic rate was significantly lower in L9981-nm23-H1 group than in L9981 group (0% vs. 100%, P<0.001). (3)nm23-H1 up-regulated mRNA and protein levels of beta-catenin, E-Cadherin, and TIMP-1, and down-regulated levels of MMP-2, CD44V6, and VEGF (P<0.01). (4) nm23-H1 up-regulated mRNA level of CD44s, protein level of CD44s didn't change (P>0.05). CONCLUSION: nm23-H1 gene can reverse malignant and metastatic phenotype of L9981 cells through regulating the expressions of lung cancer metastasis-related genes.

Animals↗
PubMed2005

[Effect of nm23-H1 on reversing malignant phenotype on human lung cancer cell line L9981].

nm23-H1 is a proven tumor metastasis suppressive gene, tumor metastasis phenotype could be reversed by transfected nm23-H1 cDNA. This study was conducted to transfect nm23-H1 cDNA into L9981 cells and to explore the function of nm23-H1 in reversing the malignant phenotype of L9981 cells. The plasmid of pLXSN-nm23-H1-EGFP was constructed by gene clone technique, and the transfected nm23-H1 cDNA cell lines of L9981-nm23-H1 was established. The protein expression of nm23-H1 was detected by Western blot. The biologic features of L9981-nm23-H1 cells were studied in vitro and in vivo. The results showed that the fusion protein of nm23-H1-EGFP was stable, continuous and expressed with high efficiency in L9981-nm23-H1 cells. The cell proliferation, colon formation and invasive ability are significantly lowered in L9981 cells transfected nm23-H1 cDNA (P < 0.01); the tumorgenesis and the lung metastasis incidence was lower in tranfected nm23-H1 cells than in L9981 and L9981-Plxsn in nude mice (P < 0.01); the rate for inhibiting tumorgenesis of nm23 -H1 was 82.56%. These data suggest that the malignant phenotype could be reversed by wild nm23-H1 gene in L9981 cells.

Animals↗
PubMed2005

[Detection of aberrant promoter CpG islands hypermethylation of GSTP1 in human primary hepatocellular carcinomas].

OBJECTIVE: To detect the aberrant promoter CpG islands hypermethylation status of GSTP1 gene in hepatocellular carcinomas (HCC) and to assess its significant role in hepatocarcinogenesis. METHODS: Surgically resected cancerous and non-cancerous liver tissues of 26 hepatocellular carcinoma patients were obtained from West China Hospital, and 11 peripheral blood samples from healthy donors as negative control were collected. Breast cancer cell line MCF-7 with CpG islands hypermethylation of GSTP1 as positive control was obtained from the Cell Bank of Chinese Academy of Sciences in Shanghai. All genomic DNA were extracted using common phenolchloroform approach, and the 5' CpG islands methylation status of GSTP1 gene was studied by methylation-specific polymerase chain reaction (MSP). RESULTS: GSTP1 gene promoter CpG island hyperthylation was detected in 88.5% (23/26) of cancerous tissues and in 69% (18/26) of corresponding non-cancerous tissues from the 26 HCC patients. None of the 11 control samples were methylation positive. CONCLUSION: The data indicates that the detection of GSTP1 gene methyl-lation may be a valuable biomarker by MSP for HCC early diagnosis and disease monitoring.

Adult↗
PubMed2005

[Growth inhibition and demethylation by a component of natural drug, CDP, in cancer cell lines].

OBJECTIVE: To investigate the inhibition of tumor cell lines' growth and the demethylation of p16 gene by a component of natural drug, CDP. METHODS: Human liver cancer cell line Huh-7 and breast cancer cell line T47D were treated with the CDP and DNA methyltransferase inhibitor, 5-azacytidine (5-aza-C). The inhibition of growth was assayed by MTT; the methylation status of p16 gene promoter was analyzed by MSP. RESULTS: 1. The CpG islands in promoter of p16 gene were identified as completely methylated in Huh-7 and T47D. 2. CDP and 5-aza-C inhibited the proliferation of Huh-7 and T47D cell lines in a dose, time-dependent mode. 3. Methylation-specific bands of CpG islands in p16 gene' promoter were still existed in Huh-7 and T47D, while unmethylation-specific bands appeared in Huh-7 after the cells being treated with 25, 50, 75 and 100 micromol/ L of CDP for 6 days as well as in T47D after the cells being treated with 50, 75 and 100 micromol/L of CDP for 6 days. 4. After the cells being treated with 50 micromol/L of CDP, the methylation-specific bands of CpG island in p16 gene' promoter were still existed in Huh-7 and T47D; unmethylation-specific bands appeared at 12 h and lasted to 144 h in Huh-7 while at 72 h and lasted to 144 h in T47D. CONCLUSION: CDP has inhibition effect on the cancer cell lines and has the ability to reverse the hypermethylated p16 gene promoter. These results suggest that CDP has great potential in the development of effective anticancer drugs.

Antineoplastic Agents, Phytogenic↗
PubMed2004

Luminescent organoboron quinolate polymers.

The synthesis of well-defined luminescent organoboron polymers via a novel three-step procedure starting from silylated polystyrene is reported. Highly selective borylation of poly(4-trimethylsilylstyrene) (PS-Si), followed by replacement of the bromine substituents in poly(4-dibromoborylstyrene) (PS-BBr) with substituted thienyl groups (R = H, 3-hexyl, 5-hexyl), and final introduction of the 8-hydroxyquinolato moiety yields a series of new organoboron quinolate polymers in 67-83% isolated yield. The hexyl-substituted polymers are highly soluble and solution-processable yielding thin films that efficiently emit light at 513-514 nm upon excitation at 395 nm.

Journal Article↗
PubMed2004

Association of low p16INK4a and p15INK4b mRNAs expression with their CpG islands methylation with human hepatocellular carcinogenesis.

AIM: To study the significance of p16 and p15 transcription suppression with hypermethylation of their genes' 5'CpG islands during human hepatocellular carcinogenesis. METHODS: The mRNA expression levels of p16 and p15 genes were evaluated in cancerous, para-cancerous and non-cancerous tissues of 20 HCC, 3 normal liver tissues from 3 accidentally died healthy adults using semi-quantitatively Northern blot. The methylation status was also assessed with methylation specific PCR. RESULTS: p16 mRNA expression level was decreased in the cancerous tissues in 60% (12/20) of HCC patients, of which 2 cases had no p16 mRNA detected, 5 cases (25%) displayed variation in the order of cancerous<para-cancerous<non-cancerous liver tissues. p15 mRNA expression level was decreased in the cancerous tissues in 50% (10/20) HCC patients, of which one case had no p15 mRNA detected, 4 cases (20%) displayed variation in the order of cancerous<para-cancerous<non-cancerous liver tissues. In cancerous, para-cancerous and non-cancerous tissues, p16 promoter CpG islands hypermethylation occurred 65%, 60% and 35%, while p15 promoter CpG islands hypermethylation occurred 50%, 40% and 25%. Of 12 HCCs with lower p16 mRNA expression level, 11 cases showed p16 promoter CpG islands methylation (91.6%). Hundred percent (10/10) HCCs with lower p15 mRNA expression level showed p15 promoter CpG islands methylation. Significant correlation between 5'CpG islands methylation and p16/p15 mRNA expression suppression was found. The decreased expression of p16/p15 mRNA or methylation of p16/p15 promoters 5'CpG island was significantly correlate with poor differentiation of HCC (P=0.0083, 0.0102, 0.00271, 0.0218, respectively, P<0.05). CONCLUSION: p16 and p15 genes transcriptional inactivation might play an important role in hepatocarcinogenesis. 5'CpG islands methylation might be the major mechanism of p16 and p15 genes inactivation in primary HCC in the studied population. 5'CpG islands methylation of p16 and p15 genes might be an early event in hepatocarcinogenesis.

Adult↗
PubMed2004

[Impact of p16INK4A and p15INK4B on human hepatocellular carcinoma cell proliferation and apoptosis].

OBJECTIVE: Both tumor suppressor p16INK4A and p15INK4B are members of INK family of CDK inhibitor. Although the role of p16 has been well documented, the role of p15 and its signaling pathway remain less well studied. This study was aimed to assess the effect of p16 and p15 on hepatocarcinoma cell lines with different status of Rb gene. METHODS: After identification of the genetic status of p16, p15 as well as Rb of human hepatocellular carcinoma (HCC) cell lines BEL7402, SMMC7721 with the use of multiple PCR, the eukaryotic expression p16 and p15 recombinants pXJ-p16 and pXJ-p15 were constructed, respectively. The existence of exogenous p16, p15 genes, and the expression of p16 and p15 were assayed by means of PCR and RNA dot blotting. Finally, the proliferation and apoptosis were studied by using MTT, colony formation assay and flow cytometry. RESULTS: Neither deletion of p16 nor p15 was detected in the two cell lines. However, Rb exons 14-16 instead of exons 22-23 deletion existed in SMMC7721. The increased mRNA expression level of p16 was found in BEL7402-p16 and SMMC7721-p16, while increased mRNA expression level of p15 was found in BEL7402-p15. The endogenous p16 and p15 genes were transcripted at low level. The cell growth and colony formation were decreased in BEL7402-p15, compared with either mock cell BEL7402 or vector control cell BEL7402-pXJ. Also shown in this study were an altered G1 phase population from 37.7% to 43.6%, an S phase population from 22% to 13% (P<0.05), and a Sub G1 peak (apoptosis peak) in BEL7402-p15. Conversely, BEL7402-p16 with endogenous p16 gene showed neither difference in cell cycle population nor difference in colony formation rate, compared with control cell groups. Additionally, SMMC7721-p16 cell growth was not inhibited by exogenous p16 gene. CONCLUSION: p15 significantly arrested cell proliferation and induced apoptosis in BEL7402 in vitro, and the function was not influenced by endogenous p15 gene. The inhibition of cell growth by p16 on HCC cells could be dependent on intact RB pathway.

Apoptosis↗
PubMed2004

[The imprinting status and expression of insulin-like growth factor 2 gene in human hepatocellular carcinoma].

OBJECTIVE: To study the imprinting status and expression level of insulin-like growth factor 2 (IGF2) gene in hepatocellular carcinoma and to provide a clue for elucidating the mechanism of carcinogenesis of hepatocellular carcinoma. METHODS: The heterozygote status of IGF2 gene was detected by restriction fragment length polymorphism. The imprinting status and expression level of IGF2 were evaluated by semi-quantitative reverse transcription-polymerase chain reaction. RESULTS: It was found that 10/18 (55.6%) of hepatocellular carcinoma showed the gain of imprinting (GOI), with 6/10 (60%) adjacent cirrhosis of liver tissues also displaying GOI of IGF2. Overexpression of IGF2 in cancer tissues was detected in 9/18 (50%) samples, but no significant difference was observed among each imprinting status. CONCLUSION: GOI of IGF2 may take part in human hepatocellular carcinogenesis.

Carcinoma, Hepatocellular↗
PubMed2004

[Research on the growth inhibition of T47D cell and reversion of p16 hypermethylation by CDP].

OBJECTIVE: To inquire into the mechanism of CDP (a purified component of Chinese crude drug) in inhibiting the breast cancer T47D cell growth. METHODS: T47D cells were treated with different concentration of 5-azacytidine (5-aza-CR) and CDP for several days. The growth rate was assessed by cell proliferation experiment (MTT colorimetric assay). The changes in apoptic peak and cell cycle distribution were detected by flow cytometry (FCM). The levels of methylation and unmethylation status of p16 were detected by methylation specific PCR (MSP). RESULTS: After treatment with the two drugs, the cell growth rate decreased in a dose and time dependent manner (P<0.05). The cell cycle was influenced by the well-chosen concentration of 5-aza-CR (2 micromol/L) and CDP (50 micromol/L): the cell number increased from 65.1% to 71.3%, 84.3% in G0/G1 phase and decreased from 19.4% to 14.3%, 7.2% in S phase. Demethylation on p16 gene occurred after treatment with any of the two drugs for 6 days. CONCLUSION: CDP can reverse p16 hypermethylation and may hence inhibit the proliferation of tumor cells.

Antineoplastic Agents, Phytogenic↗
PubMed2003

[Value of diagnosing micrometastasis by nested RT-PCR in the peripheral blood and bone marrow in non-small cell lung cancer patients].

OBJECTIVE: To evaluate the specificity, sensitivity and their clinical significance of detecting CK19 mRNA expression by nested RT-PCR for molecular diagnosis of micrometastasis in the peripheral blood and bone marrow of patients with non-small cell lung cancer. METHODS: CK19 mRNA expression was detected by nested RT-PCR in peripheral blood and bone marrow samples from 59 lung cancer patients, with samples of 11 benign pulmonary lesion patients and 20 healthy adults as control. RESULTS: The sensitivity of nested RT-PCR was 10(-6). The positive rates of micrometastasis were 33.89% (20/59) in peripheral blood and 22.03% (13/59) in bone marrow, with a highly positive correlation existing between the two groups (P < 0.05). The micrometastasis in peripheral blood and bone marrow was closely correlated with the pathological classification and cell differentiation (P < 0.05) and P-TNM stage (P < 0.01). No CK19 mRNA expression was found in the samples from patients with benign pulmonary lesion or healthy adult volunteers. CONCLUSION: The peripheral blood and bone marrow from patients with non-small cell lung cancer possesses micrometastasis that can not be detected by common methods. Nested RT-PCR technique shows favorable specificity and sensitivity in detecting the condition with definite clinical prospects.

Adult↗
PubMed2002

Well-defined boron-containing polymeric lewis acids.

A general new route to well-defined polymeric Lewis acids via borylation of silylated polymers is reported. Trimethylsilylated polystyrene (PS-Si) of controlled molecular weight and low polydispersity (PDI < 1.15) was obtained via atom transfer radical polymerization (ATRP) of 4-(trimethylsilyl)styrene. The functional polymer PS-Si was quantitatively borylated using BBr3 to give poly(4-dibromoborylstyrene) (PS-B), a novel soluble boron-containing polymeric Lewis acid. PS-B readily reacted with nucleophiles serving as a precursor to a family of new polymers with boron centers of variable Lewis acidity. Reaction of PS-B with Cu(C6F5) gave the highly Lewis acidic polymer poly[4-bis(pentafluorophenyl)borylstyrene], the first polymeric analogue of tris(pentafluorophenyl)borane.

Journal Article↗
PubMed2002

[Effects of ectogenous FHIT gene on reversing malignant phenotype of human lung adenocarcinoma cells A549].

OBJECTIVE: To explore the role of fragile histidine triad(FHIT) gene in the proliferation, apoptosis and tumorigenesis of human lung cancer cells. METHODS: FHIT gene packaged with lipofectin was transfected into the cells of a human lung adenocarcinoma cell line (A549), which stably expressed ectogenous FHIT gene. The FHIT mRNA and protein expression of A549-FHIT, A549-vector and A549 cell were detected by reverse transcription-PCR(RT-PCR), Western blot and immunocytochemical methods. The cell cycle pattern and apoptosis were assayed by using flow cytometry. RESULTS: After transfection of FHIT gene, cell growth was obviously inhibited (P<0.01). The apoptosis index of A549-FHIT (8.42%) was significantly higher than that of A549-vector (5.45%) and A549 cells (5.71%)(P<0.01). The clone-formation rate of A549-FHIT cell (21.84%) was significantly lower than that of A549-vector (28.70%) and A549 cells (31.68%, P<0.01). Compared with control cell lines, larger scale of A549-FHIT cells accumulated in G0/G1, presenting that the proportion of the cells in G0/G1 phase was obviously increased from 67.78 % to 82.35 %. Tumorigenicity of the A549 cells in nude mice was greatly inhibited by expression of ectogenous FHIT gene, the weight and volume of A549-FHIT(1.61 g/1.37 cm(3)) were significantly lower than that of A549-vector (2.45 g/1.99cm(3)) and A549 cells (2.77 g/2.27 cm(3))(P<0.05). CONCLUSION: Expression of ectogenous FHIT gene can obviously inhibit the proliferation and tumorigenesis of A549 cells, and can induce A549 cells into programmed cell death. The result of this study suggests that FHIT gene may be a tumor suppressor gene in human lung cancer cells.

Acid Anhydride Hydrolases↗