HPV18E6E7基因诱发的人胎儿食管上皮永生化和恶性转化细胞端粒长度和端粒酶活性

TELOMERE LENGTH AND TELOMERASE ACTIVITY IN IMMORTALIZED AND MALIGNANTLY TRANSFORMED HUMAN EMBRYONIC ESOPHAGEAL EPITHELIAL CELL LINES BY E6 AND E7 GENES OF HPV 18 TYPE

目的 :探讨端粒长度、端粒酶活性以及端粒酶亚单位组分 (hTERT、hTR)的表达与食管上皮细胞永生化和恶性转化之间的关系。方法 :对HPV18E6E7基因诱发的人胎儿食管上皮永生化细胞系SHEE和恶性转化细胞系SHEEC ,通过Southernblot检测端粒长度 (TRF) ,TRAP法测定端粒酶活性 ,RT PCR研究端粒酶催化亚单位 (hTERT)和端粒酶RNA成分 (hTR)的表达。结果 :SHEE细胞和SHEEC细胞的端粒平均长度比正常食管上皮细胞的明显缩短 ,但稳定维持在一定长度范围内。SHEE细胞和SHEEC细胞均具有端粒酶活性 ,并均有hTERT和hTR表达。结论 :端粒酶表达活化使端粒维持在一定长度是永生化食管上皮细胞SHEE和恶性转化细胞SHEEC能够稳定分裂增殖的重要因素之一。

Purpose: To study the relationship of the telomere length and telomerase activity to immortalization or malignant transformation of the immortalized esophageal epithelial cell line(SHEE) and malignantly transformed cell line(SHEEC) induced by E6 and E7 genes of HPV 18 type. Methods: Using SHEE and SHEEC cell lines, the telomere length(mean length of telomere restriction fragments,TRF) was examined by Southern blotting, the telomerase activity by the PCR based telomeric repeat amplification protocol(TRAP) and the expression of human telomerase reverse transcriptase(hTERT) and human telomerase RNA (hTR) by reverse transcription polymerase chain reaction(RT-PCR). Results: The telomere length in the SHEE and SHEEC was significantly shorter than that in the normal esophageal epithelial tissue, but maintained a stable length. The telomerase activity and its subunit hTERT and hTR were observed in the SHEE and SHEEC. Conclusion: A possible cause of stable division of SHEE and SHEEC is telomerase reactivitied, which maintains the telomere at a shortened and stable length.