Biomedical subjects

Jian Shen

Publications and source records attributed to Jian Shen.

63 records · Page 4Linked to original sources

PubMed2002

Mitochondria, calcium and nitric oxide in the apoptotic pathway of esophageal carcinoma cells induced by As2O3.

In order to explore the early apoptotic signal messengers and to search the apoptotic pathway, the morphological and functional changes of mitochondria were examined, and nitric oxide (NO) and calcium ions (Ca2+) were measured in the course of apoptosis in esophageal carcinoma cells induced by As2O3. The esophageal carcinoma cell line SHEEC1, established by HPV in synergy with TPA in our laboratory, were cultured with serum-free medium in a culture flask, 24-well plate and small culture chambers, and added with As2O3 at 1, 3, 5 micromol/l. After 0, 2, 4, 8, 12, 24 h of drug adding the NO were measured from extracellular cultured medium and the SHEEC1 cells were collected from flasks for electron microscopic examination. Fluorescent intensity (FI) of rhodamine 123 (Rho123) labeled cells was detected using laser confocal scanning microscope (LCSM) for evaluation of mitochondrial membrane potential. Intracellular Ca2+ of cells in small culture chambers labeled with Fluo-3 dye were measured using LCSM over time. After adding As2O3, SHEEC1 cells revealed characteristic morphological and functional changes of mitochondria such as hyperplasia, swelling and disruption, accompanying decrease of transmembrane potential (FI of Rho123 decreased). The Ca2+ level increased at once after adding As2O3 and the NO concentration increased step by step till 24 h, then apoptotic morphology of cells occurred. The results suggest that by inducement of As2O3 increasing Ca2+ and NO, the apoptotic signal messengers, will initiate the mitochondria-dependent apoptotic pathway.

Antineoplastic Agents↗

PubMed2002

[Attachment and growth of cultured fibroblast cells on chitosan/PHEA-blended hydrogels].

The chitosan/PHEA-blended hydrogels were prepared from PHEA and chitosan in various blend ratios. The water contents of the hydrogels were in the range of 50%-80% (wt). The attachment and growth of fibroblast cells(L929) on the hydrogels were studied. The results indicated the PHEA content in hydrogels has great effect on cell attachment but has little effect on the growth of L929 cells.

Animals↗

PubMed2002

[Malignant transformation of the immortalized esophageal epithelial cells].

OBJECTIVE: Immortal cell line of human embryonic esophageal epithelium (SHEE) was induced by E6E7 genes of human papillomavirus (HPV) type 18 in our laboratory. To identify the fully malignant transformation at its 85th passage (SHEE85), the malignant phenotype, tumorigenesis and invasive potency were studied. METHOD: The cultured SHEE85 cells were observed under the light and the electron microscope (EM) for cell morphology, analyzed by flow cytometry for cell cycle. The tumorigenesis was assayed by plating cells in soft-agar and transplanting cells into the nude mice and SCID mice. To detect invasive potency, cells were cultured on amniotic membrane in vitro and transplanted into peritoneal cavity of mice in vivo. RESULTS: SHEE85 cells were crowded in cultivation with different sizes and shapes under light microscope, and displayed proliferative morphology under EM. Proliferative index was 47% with 12% hyperploidy cells in determination of DNA histogram. Many large colonies grew in soft-agar (4%) and the transplanted tumors were found in all 4 nude and 4 SCID mice, with strong invasive potency demonstrated in vitro and in vivo. CONCLUSION: The immortal esophageal epithelial cell line induced by HPV18 E6 E7 is derived from a fully malignant transformation with a strong invasive potency at the 85th passage. It is also a reliable model for studying the cellular and molecular mechanisms of carcinogenesis of the esophageal carcinoma.

Animals↗

PubMed2002

Immortal phenotype of the esophageal epithelial cells in the process of immortalization.

To search for potential biomarkers used to monitor the process of immortalization, we investigated the relative level of telomerase activity and other immortal phenotypes in the SHEE esophageal epithelial cell line. This human fetal esophageal epithelial cell line, induced by human papilloma virus (HPV) 18 E6E7, was continually propagated over 100 passages. Fourteenth passage cells (SHEE14) were cultured in a flask with a serum-free medium and continually cultured to the 30th passage (SHEE30). Cells of SHEE14, SHEE20 and SHEE30 were examined according to cell morphology, cell cycle, apoptosis, contact-inhibition growth, anchorage- dependency, dose-dependency to epithelial growth factors (EGF), telomerase activity and tumorigenicity. The SHEE14 cells exhibited good differentiation with contact-inhibition and anchorage-dependent growth. The SHEE20 cells exhibited increase of senescent and apoptotic cells, and difficulty in propagation. The SHEE30 cells exhibited a higher proliferative index and some undifferentiated cells, with weakened contact-inhibition and anchorage-dependent growth. The telomerase was activated in cells of SHEE30, but not in SHEE14 and SHEE20 cells. The different response to dose-dependency to EGF was not statistically different in SHEE14 and SHEE30. Three groups of cells displayed lack of tumor formation in nude mice. Compared with SHEE14 and SHEE20, SHEE30 cells were of immortalized status with immortal phenotype, which consisted of telomerase activity, increase of cell proliferation, weakened contact-inhibition and anchorage-dependent growth, dose dependency to EGF and lack of tumor formation. From passage 14 to 30th passage, SHEE cells went through cellular senescence, apoptosis and immortalization. With a view toward diagnostic and biological aspects, telomerase activity is a crucial step and a cardinal requirement for immortalization. The telomerase activity and other immortal phenotypes are potential markers for monitoring the process of immortalization.

Animals↗

PubMed2002

[The promoter effects of sodium butyrate on the malignant transformation of the immortalized esophageal epithelium induced by human papillomavirus].

OBJECTIVE: Study on the promoter effects of sodium butyrate in high or low dosages on carcinogenesis process, based on the immortalization of human fetal esophageal epithelium induced by human papillomavirus (HPV) 18E(6)E(7) genes. METHODS: The immortalized esophageal epithelium SHEE was treated with high concentration of the sodium butyrate (80 mmol/L) and then with low concentration (5 mmol/L) for 8 weeks respectively. The cells were cultured continuously without sodium butyrate for 14 weeks. The morphology, proliferation and apoptosis of the cells were studied by phase contrast microscopy, immunohistochemistry and flow cytometry. The dead and the viable cells were assayed by fluorescent microscopy with Hoechst 33342 and Propidium iodide staining. Tumorigenesis of the cells was assessed by soft agar colony formation and by transplantation of cells into nude mice and SCID mice. RESULTS: When cells were exposed to high concentration of sodium butyrate, cell death was increased leaving few live cells. When cells were cultured in the medium with low concentration of sodium butyrate, the first proliferative stage appeared. Removal of the butyrate caused the cell to enter a crisis stage with a long doubling time resembling senescent cells. After the crisis stage, the cells progressed to the second proliferation stage with continuous replication and atypical hyperplasia. At the end of the second proliferative stage, carcinogenesis of the cells appeared with large colonies in soft-agar and tumor formation in transplanted SCID mice and nude mice. CONCLUSIONS: The malignant change of the immortalized epithelium by the effects of sodium butyrate is the consequence of a two-stage mortality mechanism: cells death by butyrate cytotoxicity and cell crisis by abrogation of sodium butyrate. These data reveal that in high dosage, sodium butyrate induces cell death and in low dosage, it induces cell proliferation, which emphasizes the importance of butyrate as a promotor of carcinogenesis.

Animals↗

PubMedDate not supplied

Another use of the alar cartilaginous flap.

BACKGROUND: Resection of the cephalic or middle portion of lateral crura of alar cartilages is a method for correcting bulbous nose in which the resected cartilages usually are discarded, resulting in a waste of autologous tissues. A silastic implant usually is used to correct saddle nose in Asian countries, but implant extrusion, a severe complication, sometimes occurs. Cartilage flaps were first reported by José to increase the projection of the nasal tip. In this study, the authors used cartilaginous flaps of the lateral crura to wrap the tip of the nasal implant for patients with bulbous and saddle noses. This study aimed to investigate the application of cartilaginous flaps of lateral crura. METHODS: A flap was created from the cephalic portion of the lateral crus of the alar cartilage, leaving the caudal portion intact. The cartilage flap remained attached at the level of the original domal segment of the middle crura. It was rotated over to wrap the tip of the silastic implant, then sutured to the other side flap. RESULTS: From March 2003, 19 patients were treated with this technique. The results were satisfactory without implant extrusion or any other complications except for nonobvious scars. CONCLUSION: The cartilage flap can reduce the incidence of implant extrusion and help to reduce the size of the bulbous tip.

Adult↗

PubMedDate not supplied

HAD: an automated database tool for analyzing screening hits in drug discovery.

Collecting, organizing, and reviewing chemical information associated with screening hits are human time-consuming. The task depends highly on the individual, and human errors may result in missing leads or wasting resources. To overcome these hurdles, we have developed a decision support system, Hits Analysis Database (HAD). HAD is a software tool that automatically generates an ISIS database file containing compound structures, biological activities, calculated properties such as clogP, hazard fragment labels, structure classifications, etc. All data are processed by available software and packed into a single SD file. In addition to search capabilities, HAD provides an overview of structural classes and associated activity statistics. Chemical structures can be organized by maximum common substructure clustering. The ease of use and customized features make HAD a chief tool in lead selection processes.

Databases, Factual↗

PubMedDate not supplied

E6/E7 genes of human papilloma virus type 18 induced immortalization of human fetal esophageal epithelium.

To study the role played by human papilloma virus (HPV) in carcinogenesis, immortalized esophageal epithelial cells were induced by E6 and E7 genes of HPV type 18 and the biological behavior was studied. Human fetal esophageal epithelial cells were transfected with recombined HPV18E6E7AAV and were cultured and passaged in medium M199. In both the 10th passage (SHEE10) and the 31st passage (SHEE31), their proliferative rates by flow cytometry and their abilities to grow and form colonies in soft agar, or to form tumors in SCID mice were examined. The HPV18 genes of E6E7 and its expression were determined using PCR methods. Cellular telomerase activity was detected by TRAP and chromosomes were analyzed by standard method. Immortalized cell lines of esophageal epithelium induced by the HPV18E6E7 were successfully established and cultured for >100 passages over 4 years. The result of PCR showed that the E6E7 gene of HPV18 was detectable in both cell clones. Both of them were unable to grow in soft-agarose medium and failed to produce tumors in SCID mice. Flow cytometry demonstrated an average of 43% proliferation index in SHEE31, but 28% in SHEE10. Telomerase activity was clearly identified in SHEE31 but not in SHEE10. Cytogenetic analysis demonstrated progression of chromosomal abnormalities with increasing trisome. Our data indicated that genes E6/E7 of the HPV18 were capable of inducing immortalization in fetal esophageal epithelial cells. The immortal phenotype requires both activation of telomerase and genetic alterations that abrogate normal differentiation and promote cellular proliferation. This cell line can assist us to characterize the role played by HPV in carcinogenesis.

Agar↗

PubMedDate not supplied

The inhibition of growth and angiogenesis in heterotransplanted esophageal carcinoma via intratumoral injection of arsenic trioxide.

To investigate the antitumor action of arsenic trioxide (As2O3) by intratumoral injection into solid tumors, tumor growth inhibition (TGI) and angiogenesis of heterotransplanted esophageal carcinoma in mice was carried out. The cultured human esophageal carcinoma cells were inoculated into both laterals of the abdominal wall of severe combined immunodeficient (SCID) mice. When both lateral tumors had grown to about 10x8x5 mm(3), the right tumors were treated with an intratumoral injection of As2O3 in dosage of 1, 5 and 10 microg per day, respectively, for 10 days sequentially. Left tumors were treated with PBS (phosphate buffer solution) as control. The weight of transplanted tumor masses were measured and counted for TGI. The tissue of tumor, liver, kidney, heart, lung and brain was examined histopathologically and tumor tissues were examined by light- or electron-microscope. Ki-67 and CD34 were assessed by immunohistochemistry and positive nuclei of Ki-67 and microvessel density (MVD) labeled by CD34 were measured. The results revealed that on the 20th day after the first injection, As2O3-treated tumors were suppressed markedly as compared with the contrarily situated tumor, accompanied by a marked apoptosis and necrosis in tumor cells. The tissue of liver, kidney, heart, lung and brain was unaffected by As2O3. MVD in tumor tissue was decreased in the right side tumor with the significant difference in the 5 micro g and 10 micro g group (p<0.01). TGI was 5.80 (p>0.05), 58.66 (p<0.01) and 73.97% (p<0.01) in the 1, 5 and 10 micro g groups respectively, but 2.21% (p>0.05) in the control group. Conclusively, a repeated administration of As2O3 (5 and 10 microg x 10) induced an increase of tumor growth inhibition and decrease of angiogenesis in the solid tumor in tumor progressive periods. These results suggest that intra-tumoral injection of As2O3 may be investigated as a modality to treat some solid tumors.

Animals↗