The promoter effects of sodium butyrate on the malignant transformation of the immortalized esophageal epithelium induced by human papillomavirus / 中华病理学杂志

<p><b>OBJECTIVE</b>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.</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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.</p><p><b>CONCLUSIONS</b>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.</p>

Malignant transformation of the immortalized esophageal epithelial cells / 中华肿瘤杂志

<p><b>OBJECTIVE</b>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.</p><p><b>METHOD</b>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.</p><p><b>RESULTS</b>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.</p><p><b>CONCLUSION</b>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.</p>

Telomerase activity analysis of esophageal carcinoma using microdissection-TRAP assay / 中华医学杂志(英文版)

<p><b>OBJECTIVES</b>To investigate telomerase activity in esophageal squamous cell carcinoma (SCC) and its preneoplasia lesions, and to study the relationships between telomerase activity and cancer differentiation, cancer invasiveness, and lymphatic metastasis.</p><p><b>METHODS</b>Telomerase activity in esophageal SCC tissues, adjacent dysplasia tissues and normal epithelia from the surgical edge were assessed by microdissection-TRAP (telomeric repeat amplification protocol)-silver staining assay.</p><p><b>RESULTS</b>Telomerase activity was detected in 37 (82.2%) of 45 esophageal tumors, 23 (79.3%) of 29 dysplasias, and 2 (5%) of 40 normal epithelia. There was a significant difference in activity between dysplasia and normal epithelium, as well as between tumor and normal epithelium. Twenty-six (92.9%) of 28 tumors with lymphatic metastasis had detectable telomerase activity compared to 11 (64.7%) of 17 non-lymphatic metastasis tumors. These relationships were statistically significant (P < 0.05), but the one between telomerase activity and tumor grade was not.</p><p><b>CONCLUSION</b>Telomerase activity was high both in esophageal SCC and their preneoplasia lesions. The telomerase activity in SCC tissue was related to lymphatic metastasis, but not to cancer differentiation.</p>

The Effects of Arsenite Trioxide in Various Concentrations on the Esophageal Carcinoma Cell Line / 中国肿瘤生物治疗杂志

Objective: To further study the effects of As 2 O 3 in various concentrations on the esophageal carcinoma cell line. Methods: The esophageal malignant transformed epithelial cells (SHEEC1) were induced by HPV18 in synergy with TPA in our laboratory. The cells cultured in flask and 24 wells plate were treated by As 2 O 3 with concentrations of 1, 3 and 5 ?mol/L for 2, 4, 8, 16, 24 h respectively. The morphologic changes of cells were observed under election microscopy. The mitotic index (MI) of living cells was calculated by phase contrast microscopy and the cells with TdR uptake were examined by autoradiography. The proliferative index (PI) and apoptotic index (AI) were assayed by flow cytometry. Results: A low dosage of As 2 O 3 (1.0 ?mol/L) enhancing the protiferative rate of SHEEC1 was demonstrated with TdR uptake, MI and PI increased. The high AI and low PI were found in the high concentrations (3 and 5 ?mol/L)of As 2 O 3 . The morphological changes of apoptosis and necrosis were found in 24 h after As 2 O 3 in high concentrations (3 and 5 ?mol/L) administrated. Conclusion: The effects of As 2 O 3 in various concentrations are different. Low concentration of As 2 O 3 promotes the proliferation of the esophageal carcinoma cells by increment of DNA synthesis. In high concentration of As 2 O 3 apoptosis and necrosis are induced.