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Biomedical subjects

Yong-liang Zhu

Publications and source records attributed to Yong-liang Zhu.

7 recordsLinked to original sources
PubMed2006

[Relation between mutant p53 and multidrug resistance in gastric cancer].

OBJECTIVE: To explore the relationship between mutant p53 and multidrug resistance in gastric cancer. METHODS: Mutant p53 (mp53) and mp53+sv40Tag were transferred to gastric cancer cell line SGC-7901. The MDR-1 mRNA was examined using RT-PCR, and the difference in chemotherapeutic sensitivity of SGC-7901 cells with mutant p53 was compared with those with mp53+sv40Tag and controls by MTT method. RESULTS: SGC-7901 cells with mutant p53 showed higher MDR-1 mRNA than that of other two groups. SGC-7901 cells with mutant p53 showed higher chemotherapeutic sensitivity to 5-Fu than that with mp53+sv40Tag and control (P<0.05), but no difference between those with mp53+sv40Tag and control (P>0.05). SGC-7901 cells with mutant p53 and those with mp53+sv40Tag showed higher chemotherapeutic sensitivity to ADM than control (P<0.05), but no difference between those with mp53 and with mp53+sv40Tag (P>0.05). There was no difference in chemotherapeutic sensitivity of SGC-7901 cells with mutant p53 compared with those with mp53+sv40Tag and control to CDDP (P>0.05). CONCLUSION: Mutante p53 genes relates to multidrug resistance of gastric cancer.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed2005

[Serum levels of several chemokines in patients with rheumatoid arthritis].

OBJECTIVE: To explore the role of several chemokines in rheumatoid arthritis (RA) and their clinical significance. METHOD: ELISA was used to detect the serum levels of interleukin (IL)-8, interferon-gamma inducible protein (IP)-10, and RANTES in 58 active RA patients, 29 clinically remissive RA patients, 21 osteoarthritis (OA) patients, and 30 healthy volunteers. Clinical data of these patients were compared between different groups. RESULTS: The serum levels of IL-8, IP-10 and RANTES in the active RA patients were significantly higher than those of the healthy controls and OA patients. The serum level of IP-10 of the active patients was higher than that of the clinically remissive patients. The index IL-8/IP-10 x RANTES/IP-10 of the active patients was higher than that of the healthy controls (P = 0.01). The serum RANTES level was positively correlated with erythrocyte sedimentation rate, C-reactive protein, platelet count, and numbers of swollen joints, and was negatively correlated with the hemoglobin level. The serum level of IP-10 was negatively correlated with X-ray image grade of hand and wrist joints. CONCLUSION: The serum levels of IL-8, IP-10 and RANTES significantly increase in active RA. The level of RANTES may be a useful additional marker for disease activity and the level of IP-10 can be used as an index of prognosis.

Adult↗
PubMed2005

Immortalization of human umbilical vein endothelial cells with telomerase reverse transcriptase and simian virus 40 large T antigen.

OBJECTIVE: To establish normally conditionally-immortalized human umbilical vein endothelial cells (HUVECs) by ectopic expression of the human telomerase catalytic enzyme (hTERT) and simian virus 40 large T (SV40 LT) antigen. METHODS: Primary HUVECs were transfected with recombinant retrovirus containing hTERT or SV40 LT respectively. Subsequently drug resistant cell clones were screened and expanded for further studies. Endothelial cell biomarkers were confirmed by examination. RESULTS: The morphological phenotype of the transfected cells was similar to the non-transfected cells. Von Willebrand factor, hTERT and SV40 LT could be detected in transfected HUVECs. Moreover, higher telomerase activity in transfected cells was maintained for over 50 population doublings compared with only low level of endogenous telomerase transiently at early population doublings in primary HUVECs. When exposed to TNF-alpha (tumor necrosis factor-alpha), the expression of E-selectin in transfected cells was significantly up-regulated, but no alteration of endothelial lipase was found. CONCLUSION: Ectopic coexpression of hTERT and SV40 LT can effectively immortalize HUVECs without tumorigenicity in vitro. Immortalized HUVECs may be an ideal target of further molecular function studies.

Antigens, Polyomavirus Transforming↗
PubMed2004

Distribution of H.pylori antigens in gastric mucosa and its significance.

OBJECTIVE: To investigate the distribution of H.pylori antigens in the gastric mucosa in patients with H.pylori infection, and the relationship between the distribution and gastric cancer. METHODS: Of 112 patients confirmed by pathological study to have chronic superficial gastritis, precancerous changes (chronic atrophic gastritis, intestinal metaplasia or atypical hyperplasia) and gastric cancer, 28 were H.pylori negative and 84 were H.pylori positive. H.pylori antigens in the gastric mucosa were detected by immunohistochemistry. RESULTS: The H.pylori positive group, comprised 12 of 22 (50.0%) in the chronic superficial gastritis group, 22 of 25 (88.0%) in the precancerous changes group and 13 of 35 (37.1%) in the gastric cancer group. The positive rates of H.pylori antigens in the cytoplasm progressively increased, respectively at 0.0% (0/12), 63.6% (14/22) and 84.6% (11/13) for the same groups (chi(2)=19.76, P=0.000); H.pylori antigens were located in the mucus layer and above the neck of the mucosal gland in 9 of 12 (75.0%) cases with chronic superficial gastritis, at the neck of the mucosal gland and the isthmus in 12 of 22 (54.5%) cases with precancerous changes, below the isthmus in 9 of 13 (69.2%) cases with gastric cancer (chi(2)=25.30, P=0.000). In the H.pylori negative group, no H.pylori antigen was observed. CONCLUSION: With the progression of chronic superficial gastritis-->precancerous changes-->gastric cancer, H.pylori antigens progressively migrated from the outer part to the inner part of the cell, and from the superficial to the deep gastric mucosa.

Antigens↗
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

Biological activity of the virulence factor cagA of Helicobacter pylori.

BACKGROUND: China is one of the countries with the highest incidence of H. pylori and more than 9090 isolates possessed the cagA gene. This study was to evaluate the biological activity of the H. pylori virulence factor cagA isolated from Chinese patients. METHODS: cagA DNA fragments were amplified from the genomic DNA and subsequently cloned into the mammalian expression vector for cell transfection and DNA sequencing. cagA protein, phosphorylated-tyrosine cagA and the complex of cagA precipitated with SHP-2 were identified respectively by western blot in the crude cell lysate from conditionally immortalized gastric epithelial cells at 48 hours after transfection with cagA DNA. In addition, the ability of induction of scattering phenotype was examined after transient expression of cagA in AGS cells. RESULTS: The C-terminal half of cagA contained only one repeated sequence and three tandem five-amino-acid motifs glutamic acid-proline-isoleucine-tyrosine-alanine (EPIYA). Moreover, the amino acid sequence of D2 region in repeated sequence was aspartic acid-phenylanaline-aspartic acid (D-F-D) which was significantly distinguished from the three repeated sequences and aspartic acid-aspartic adid-leucine (D-D-L) in the western standard strain NCTC11637. Western blot revealed that cagA became phosphorylated in tyrosine site and bound with SHP-2 after transient expression of cagA DNA in gastric epithelial cells. Transient expression of cagA in AGS cells showed that cagA was able to induce the elongation phenotype although to a lesser extent than western strains. CONCLUSIONS: cagA perturbs cell signaling pathways by binding with SHP-2. However, significant difference exists in amino acid sequence and biological function of cagA in Chinese compared with those of western countries.

Amino Acid Sequence↗