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Biomedical subjects

Shu Zheng

Publications and source records attributed to Shu Zheng.

At least 73 records · Page 4Linked to original sources
PubMed2004

Intra-tumor injection of H101, a recombinant adenovirus, in combination with chemotherapy in patients with advanced cancers: a pilot phase II clinical trial.

AIM: H101, an E1B 55 kD gene deleted adenovirus, has been shown to possess oncolysis activity experimentally and proved to be safe in preliminary phase I study. The current study was designed to evaluate its anti-tumor activity and toxicity in combination with chemotherapy in patients with late stage cancers. METHODS: H101 5.0x10(11) virus particles were given by intra-tumor injection daily for five consecutive days at every three-week cycle, combined with routine chemotherapy, to one of the tumor lesions of 50 patients with different malignant tumors. Tumor lesions without H101 injection in the same individuals were used as controls. The efficacy and toxicity were recorded. RESULTS: Forty-six patients were evaluable with a 30.4% response rate. H101 injection in combination with chemotherapy induced three complete response (CR) and 11 partial response (PR), giving an overall response rate of 28.0% (14/50) among intention-to-treat patients. The response rate for the control lesions was 13.0%, including one case with CR and five cases with PR, which was significantly lower than that for the injected lesions (P<0.05). Main side effects were fever (30.2%) and pain at the injected sites (26.9%). Grade 1 hepatic dysfunction was found in four patients, grade 2 in one patient, and grade 4 in one patient. Hematological toxicity (grade 4) was found in four patients. CONCLUSION: Intra-tumor injection of the genetically engineered adenovirus H101 exhibits potential anti-tumor activity to refractory malignant tumors in combination with chemotherapy. Low toxicity and good tolerance of patients to H101were observed.

Adenoviridae↗
PubMed2004

Honokiol: a potent chemotherapy candidate for human colorectal carcinoma.

AIM: To investigate the anticancer activity of honokiol on RKO, a human colorectal carcinoma cell line in vitro and in vivo, and to evaluate its possible use in clinic. METHODS: In vitro anticancer activity of honokiol was demonstrated by its induction of apoptosis in tumor cells. We analyzed cell proliferation with MTT assay, cell cycle with flow cytosmeter, DNA fragment with electrophoresis on agarose gels. To test the mechanism of honokiol-induced apoptosis, Western blotting was used to investigate the factors involved in this process. The pharmacokinetics study of honokiol was tested by high phase liquid chromatography. In in vivo study, Balb/c nude mice were incubated with RKO cells. Honokiol was injected intraperitoneally every other day into tumor bearing Balb/c nude mice. RESULTS: Our results showed that honokiol induced apoptosis of RKO cells in a time- and dose-dependent manner. At 5-10 microg/mL for 48 h, honokiol induced apoptosis through activating Caspase cascades. Pharmacokinetics study demonstrated that, honokiol could be absorbed quickly by intraperitoneal injection, and maintained in plasma for more than 10 h. In nude mice bearing RKO-incubated tumor, honokiol displayed anticancer activity by inhibiting tumor growth and prolonging the lifespan of tumor bearing mice. CONCLUSION: With its few toxicity to normal cells and potent anticancer activity in vitro and in vivo, honokiol might be a potential chemotherapy candidate in treating human colorectal carcinoma.

Animals↗
PubMed2004

Induction of HSF1 expression is associated with sporadic colorectal cancer.

AIM: To explore the activation of signal transduction pathways related with the carcinogenesis of sporadic colon cancers. METHODS: A gene array monitoring the activation of 8 signal transduction pathways (PathwayFinder GEArray) was used to screen the differentially expressed genes between colorectal cancer and normal colon tissues. The differentially expressed genes were further analyzed by RT-PCR, using RNA derived from colorectal cancer and normal colon tissue of 35 patients. RESULTS: The expression of HSF1, HSF27, HSP90 and iNOS was increased in colon cancer tissues compared to normal colon tissue using PathwayFinder GEArray. The RT-PCR results showed that the expression of HSF1 was increased in 86% (30/35) patients and the expression of iNOS was increased in 63% (22/35) patients. CONCLUSION: The induction of HSF1 gene expression is associated with sporadic colon cancer. HSF1 induces heat shock stress signaling pathway, which might play a role in the carcinogenesis of sporadic colorectal cancer.

Adult↗
PubMed2004

An integrated approach to the detection of colorectal cancer utilizing proteomics and bioinformatics.

AIM: To find new potential biomarkers and to establish patterns for early detection of colorectal cancer. METHODS: One hundred and eighty-two serum samples including 55 from colorectal cancer (CRC) patients, 35 from colorectal adenoma (CRA) patients and 92 from healthy persons (HP) were detected by surface-enhanced laser desorption/ionization mass spectrometry (SELDI-MS). The data of spectra were analyzed by bioinformatics tools like artificial neural network (ANN) and support vector machine (SVM). RESULTS: The diagnostic pattern combined with 7 potential biomarkers could differentiate CRC patients from CRA patients with a specificity of 83%, sensitivity of 89% and positive predictive value of 89%. The diagnostic pattern combined with 4 potential biomarkers could differentiate CRC patients from HP with a specificity of 92%, sensitivity of 89% and positive predictive value of 86%. CONCLUSION: The combination of SELDI with bioinformatics tools could help find new biomarkers and establish patterns with high sensitivity and specificity for the detection of CRC.

Biomarkers, Tumor↗
PubMed2004

Honokiol induces apoptosis through p53-independent pathway in human colorectal cell line RKO.

AIM: To investigate the signal pathway of honokiol-induced apoptosis on human colorectal carcinoma RKO cells and to evaluate whether p53 and p53-related genes were involved in honokiol-treated RKO cells. METHODS: Cell cycle distribution and subdiploid peak were analyzed with a flow cytometer and DNA fragment with electrophoresis on agarose gels. Transcriptional level of Bax, Bcl-2, Bid and Bcl-xl was accessed by RT-PCR. Western blotting was used to measure p53 protein expression and other factors related to apoptosis. Proliferation inhibition of two cell lines (RKO, SW480) with high expression of p53 and one cell line with p53 negative expression (LS180) was monitored by MTT assay. RESULTS: Honokiol induced RKO cell apoptosis in a dose-dependent manner. The mRNA expression level and protein level of Bid were up-regulated while that of Bcl-xl was down-regulated, but no changes in Bax and Bcl-2 were observed. Western blotting showed p53 expression had no remarkable changes in honokiol-induced RKO cell apoptosis. LS180 cells treated with honokiol exhibited apparent growth inhibition like RKO cells and Sw480 cells. CONCLUSION: Honokiol can induce RKO cells apoptosis through activating caspase cascade by p53-indepenent pathway.

Antineoplastic Agents, Phytogenic↗
PubMed2004

[SNC19/ST14 gene transfection and expression influence the biological behavior of colorectal cancer cells].

OBJECTIVE: To study the effect of SNC19/ST14 gene transfection and expression into colorectal cancer cells on biological behavior. METHODS: The recombination vector pSecTag2a-SNC19/ST14 was constructed, and transfected into the RKO colorectal cancer cell line by liposome. The transfected cell was screened by real time PCR, Western Blot and Immunohistochemical technique. The population doubling time (T(D)) and cell cycle of the transfected cell were analyzed by MTT assay and flow cytometer. Rhodamine-labeled Phallodin was used to label the cell cytoskeletal protein-F-actin, and the F-actin distribution was observed by confocal scanning microscope. The adhesion ability of the transfected cell to extracellular matrix (ECM) was measured by MTT assay. RESULTS: The full length Open Reading Frame (ORF) of SNC19/ST14 gene was inserted into the vector pSecTag2a, and transfected into RKO cells, and expressed successfully. The changes of F-actin organization took place in transfected cell. The Adherence ability of the transfected cell to ECM was decreased, but the proliferation ability was not significantly changed except highly expressing of the SNC19/ST14, and not the cell cycle and the apoptosis. CONCLUSION: SNC19/ST14 gene was successfully expressed into the RKO cell line, and could influence on the cell cytoskeletal protein (F-actin) organization and on cell adherence ability to ECM, but could not make the cell cycle, apoptosis and proliferation ability change significantly.

Actins↗
PubMed2004

[Study on relationship of fucosyltransferase gene types in breast cancer with metastasis and prognosis].

OBJECTIVE: To assess the association of five types of fucosyltransferase gene (Fuc-T), the important biosynthesis gene of sialylated carbohydrate antigens (Sialyl Lewis A, Sialyl Lewis X), with metastasis and prognosis of breast cancer. METHODS: The real-time quantitative PCR of five-type Fuc-T III, IV, V, VI, VII genes was performed in 80 patients with breast cancer. RESULTS: The result showed that Fuc-TVII gene had higher gene copy compared to other type of Fuc-T in breast cancer. The grading of Fuc-TVII gene was related to lymph node metastasis and poor disease-free survival. Statistically difference was significant (P < 0.01). Fuc-T III, IV, V, VI gene were not significant relation to the metastasis and prognosis in 80 cases. CONCLUSIONS: These findings suggest that Fuc-TVII gene is a prognostic indicator of breast cancer, and it may be play an important role in the biosynthesis of sialylated carbohydrate antigens in breast cancer.

Adult↗
PubMed2004

Amino acid uptake in arterio-venous serum of normal and cancerous colon tissues.

AIM: To investigate the difference of amino acid uptake between normal and cancerous colon tissues. METHODS: Sixteen patients with colon cancer were enrolled in our study. Blood samples were taken during operations, serum amino acid concentrations of blood from cancerous or normal colon were analyzed. Amino acid uptake rate was calculated by the A-V difference and evaluated statistically. RESULTS: Except for methionine, the uptake rate of amino acids in cancer was higher than that in normal colon (25.01% vs -2.29%, P<0.01). The amino acid uptake rate did not correlate to the size of tumor mass (P>0.05). There was no statistical significance in the amino acid uptake rate according to the Dukes stage, though it was higher in patients with Dukes stage C or D than that with Dukes stage B (P>0.05). CONCLUSION: Abnormal synthetic metabolism of colon cancer may contribute to its higher amino acid uptake rate than that of normal colon.

Adult↗
PubMed2004

Nuclear factor Y regulation and promoter transactivation of human ribonucleotide reductase subunit M2 gene in a Gemcitabine resistant KB clone.

Overexpression of human ribonucleotide reductase subunit M2 (hRRM2) has been shown as a potential factor causing Gemcitabine (Gem) resistance. We hypothesized the nuclear factor Y (NF-Y) would transcriptionally regulate hRRM2 and contribute to overexpression of hRRM2 in a Gem resistant clone. A luciferase and gel shift assay, and a Southwestern blot were employed to analyze the promoter activity of hRRM2. The data exhibited the hRRM2 promoter was upregulated almost 5-fold in the Gem resistant KB clone (KBGem) via three sequential CCAAT boxes located in the proximal promoter region. Nuclear extracts from KB and KBGem could interact with the CCAAT motif of the hRRM2 proximal promoter region, and could form DNA-protein complexes with different binding patterns. The complexes could be further recognized with antibodies against NF-Y subunits A and B. Histone deacetylases (HDAC) involvement in NF-Y transcription repression in the KBGem clone was examined. A HDAC activity assay revealed a 3-fold decrease of HDAC activity in the KBGem clone compared to KB cells. Parental cells were treated with trichostatin A (TSA), a HDAC inhibitor. NF-Y transactivation was induced, resulting in an increase of hRRM2 expression. This led to an expanded dCTP pool and an abrogated [3H]Gemcitabine incorporation. In addition, microarray analysis results showed most of the proliferation-related genes were upregulated in KBGem. This finding was consistent with enhanced NF-Y transactivation in KBGem. In summary, upregulation of NF-Y transactivation increased hRRM2 transcription, which played a pivotal role in the Gem resistant KB clone.

Antimetabolites, Antineoplastic↗
PubMed2004

Special fasciculiform cataract caused by a mutation in the gammaD-crystallin gene.

PURPOSE: To identify ultrastructure changes and genetic defects associated with a special fasciculiform autosomal dominant congenital cataract (ADCC) affecting a large Chinese family. METHODS: Members of the Chinese family affected by this special fasciculiform ADCC were studied. Clinical examinations, light and transmission electron microscopy of the removed lens tissue, linkage analyses using polymorphisms of microsatellite markers, and mutational analyses of candidate genes by direct sequencing were performed. RESULTS: The thirteen affected individuals in the family showed no variability between one another. The lens fiber cells showed focal degeneration, dense globular intracellular deposits, and an enlarged intercellular space. This ADCC was associated with a locus on chromosome 2q33-35 (maximum lod score [Zmax]=3.34; theta=0.05). Mutational analyses of the candidate genes (gamma-crystallin; CRYG), identified a C->A heterozygous transversion at nucleotide position 70 in the gammaD-crystallin gene (CRYGD) exon2, which co-segregated with the presence of ADCCs and was not observed in 100 unrelated controls. CONCLUSIONS: This study identified ultrastructure changes and genetic defects associated with a special fasciculiform ADCC affecting a large Chinese family. It appeared to be caused by a missense mutation in the CRYGD gene, further supporting the notion that alterations to CRYG play an important factor in human cataract formation.

Cataract↗
PubMed2004

Somatic mutations of APC gene in carcinomas from hereditary non-polyposis colorectal cancer patients.

AIM: To investigate the mutational features of adenomatous polyposis coli (APC) gene and its possible arising mechanism in hereditary non-polyposis colorectal cancers (HNPCC). METHODS: PCR-based In Vitro Synthesized Protein Test (IVSP) assay and sequencing analysis were used to confirm somatic mutations of whole APC gene in 19 HNPCC cases. RESULTS: Eleven cases with 13 mutations were determined to harbor APC mutations. The prevalence of APC mutation was 58%(11/19). The mutations consisted of 9 frameshift and 4 nonsense ones, indicating that there were more frameshift mutations (69%). The frameshift mutations all exhibited deletion or insertion of 1-2 bp and most of them (7/9) happened at simple nucleotide repeat sequences, particularly within (A)n tracts (5/9). All point mutations presented C-to-T transitions at CpG sites. CONCLUSION: Mutations of APC gene were detected in more than half of HNPCC, indicating that its mutation was a common molecular event and might play an important role in the tumorigenesis of HNPCC. Locations of frameshift mutations at simple nucleotide repeat sequences and point mutations at CpG sites suggested that many mutations probably derived from endogenous processes including mismatch repair (MMR) deficiency. Defective MMR might affect the nature of APC mutations in HNPCC and likely occur earlier than APC mutational inactivation in some patients.

Carcinoma↗
PubMed2004

A trans-Golgi network retention signal YQRL fused to ricin A chain significantly enhances its cytotoxicity.

Ricin enters the cells by receptor-mediated endocytosis, followed by translocation across the membranes of intracellular organelles. A trans-Golgi retention peptide signal YQRL was fused to the C-terminus of ricin A chain (RTA) by polymerase chain reaction. The recombinant RTA and RTA-YQRL were expressed in Escherichia coli using plasmid pKK223.3 under the control of a tac promoter. The recombinant proteins were purified by affinity chromatography on a Blue-Sepharose 6B column. The cytotoxicities of RTA and the fusion toxin RTA-YQRL were measured by the MTT assay in HeLa, SKOV-3, and WISH cells following fluid-phase endocytosis. The rRTA-YQRL was 2-, 10-, and 40-fold more cytotoxic than rRTA itself in the three cell lines, respectively. The results indicate that addition of a TGN retention signal YQRL to the C-terminus of RTA can markedly increase its cytotoxicity, suggesting TGN may play an important role in the intracellular routing and translocation of RTA.

Amino Acid Sequence↗
PubMed2004

Expression of ricin A chain and ricin A chain-KDEL in Escherichia coli.

Ricin and its A chains can be used to conjugate with monoclonal antibodies to prepare immunotoxins. Ricin A chain (RTA) and its modification RTA-KDEL (ER-retrieval signal) were expressed with the pKK223.3 system in Escherichia coli under control of a tac promoter. The recombinant proteins can be purified by one-step affinity chromatography on a column of Blue-Sepharose 6B. The toxicities of RTA and its mutant RTA-KDEL were evaluated by the MTT assay in HeLa, MCF, and ECV-304 cells following fluid-phase endocytosis. RTA-KDEL was somewhat more cytotoxic than RTA itself in the different cell lines. The results suggest that rRTA-KDEL may be useful for the synthesis of more potent immunotoxins.

Chromatography, Affinity↗
PubMed2004

Genetic characterization of Chinese hereditary non-polyposis colorectal cancer by DHPLC and multiplex PCR.

BACKGROUND: Hereditary non-polyposis colorectal cancer (HNPCC) is an autosomal dominant disease due to germline mutations of human mismatch repair genes, mainly hMLH1 and hMSH2. The aim of the present study was to identify the point mutations and large genomic deletions of hMLH1 and hMSH2 genes in 14 Chinese HNPCC families. METHODS: Fourteen families fulfilling the Chinese HNPCC criteria were involved in this study. Genomic DNA isolated from peripheral blood samples was analyzed. Point mutations were detected by denaturing high performance liquid chromatography (DHPLC) followed by DNA sequencing. Multiplex polymerase chain reaction and GeneScan analysis were employed to detect the large genomic deletions of these two genes. RESULTS: Four of the 14 probands (29%) had sequence abnormalities that probably affect the protein function in the exonic regions of hMLH1 and hMSH2 genes. Included were one complete deletion of exons 1-7 and one missense mutation of the hMSH2 gene, and one nonsense mutation and one missense mutation of the hMLH1 gene. The large genomic deletion accounted for 25% (one out of four) of all mutations. Half (two out of four, 50%) of the mutations were missense mutation. In addition, one silent mutation, four polymorphisms in the exonic regions and four polymorphisms in the intronic regions were also discovered. CONCLUSIONS: Point mutations and large genomic deletions of the hMLH1 and hMSH2 genes were responsible for nearly one-third of Chinese HNPCC families. Detection of large genomic deletions should be involved in the routine screening manual for HNPCC families.

Adaptor Proteins, Signal Transducing↗
PubMed2004

Study on interleukin-18 gene transfer into human breast cancer cells to prevent tumorigenicity.

To study the effect of interleukin-18 gene transfection on the tumorigenesis of breast cancer cell line Bacp37, human breast cancer cell line Bcap37 were transfected with Lipofectamine and selected by G418. The biological expression of rhIL-18 was tested by RT-PCR and ELISA method; nude mice were injected with Bcap37 cell with or without the hIL-18 gene. The hIL-18 cDNA was successfully integrated into Bcap37 cell; 126.3+/-4.5 pg hIL-18 secreted by one million transduced cells in 24 hours. Nude mice injected with IL-18 gene engineered Bcap37 cell had no tumor growth. These findings indicated that human breast cancer cells were successfully modified by the gene of IL-18 cytokine; the IL-18 gene engineered Bcap37 cells secreted hIL-18 and lost their tumorigenicity. The Bcap37 cells transduced with IL-18 gene may be used as breast cancer vaccine.

Animals↗
PubMed2004

[Conditionally immortalized human colorectal crypt cell line].

OBJECTIVE: To establish human colorectal crypt cell line. METHODS: Colorectal crypt cells were separated from human fetal gut by dispase I digestion, AKP-negative cells from fetal colorectal crypt were collected and cultured on Matrigel matrix. Subsequently the primary cultured cells were transfected with recombinant retrovirus containing human telomerase reverse transcriptase (hTERT) and simian virus 40 large T antigen (SV40 LT) in 48 h. The characterization of immortalized cells was identified after the transfection and cells were screened with antibiotics for 12 approximately 16 weeks and expanded. RESULTS: Mucin, cytokeratin-pan, 8, 19 were presented in immortalized cells by immunohistochemical staining; ectopic expressions of both hTERT and SV40 LT were also found in immortalized cells by Western blotting. Agarose electrophoresis showed that the cells expressed Musashi-1 mRNA. No evidence of carcinogenesis was found in nude mouse experiment and soft-agarose cloning test. CONCLUSION: The immortalized human colorectal crypt cells were characterized and the established cell line may be an ideal target for carcinogenesis study in vitro.

Cell Line, Transformed↗
PubMed2004

[Study of an enhancer in promoter region of human colorectal cancer related ST13 gene].

OBJECTIVE: To study the base sequence of an enhancer in up-stream 5'-flank near regulation region (from -595 to +74) of human colorectal cancer related gene ST13. METHODS: Several deletion PCR primers were designed. Amplified DNA fragments of ST13 gene 5'-flank near region were cloned with pGEMT-EASY vector and sequenced; then subcloned into several pGL2 report vectors respectively. Equal quantitative recombined DNA was transfected into SW620 cell lines and the luciferase activity was checked. RESULTS: Several amplified base sequence fragments (669 bp,263 bp,163 bp) in pGL2-Basic all enhanced and promoted luciferase gene expression strongly. The 47 bp and 101 bp fragments didn't promote luciferase gene expression. 101 bp fragment recombined with pGL2-Promoter enhanced luciferase gene expression distinctly (P<0.01), but the effect was less strong than the positive pGL2-Control(P<0.05). CONCLUSION: The base sequence 101 bp (from -595 to -494) in up-stream 5'-flank near regulation region of colorectal cancer related gene ST13 is an enhancer regulating gene transcript.

Base Sequence↗