胃癌及癌前组织中端粒酶活性及端粒限制性片段长度的检测及其临床意义

TELOMERASE ACTIVITY AND TELOMERIC RESTRICTION FRAGMENT IN GASTRIC TUMOR AND PREMALIGNANT LESIONS:DETERMINATION AND ITS SIGNIFICANCE

采用ＴＲＡＰ法检测了１７６例不同病变胃粘膜组织端粒酶活性（ＴＡ），同时采用Ｓｏｕｔｈｅｒｎ杂交技术检测了３５例胃癌及其相应的１９例癌旁和１３例手术切缘组织端粒限制性片段（ＴＲＦ）长度。结果显示：①１７６例不同胃粘膜病变中，慢性萎缩性胃炎（ＣＡＧ）、肠上皮化生（ＩＭ）、异型增生（Ｄｙｓ）及胃癌（ＧＣ）ＴＡ阳性检出率分别为２４．６％、３８．５％、３７．５％及９２．３％，而正常组织（Ｎ）未检出ＴＡ，明显低于以上各组（Ｐ＜０．０１～０．０５），癌组织ＴＡ阳性率亦明显高于ＣＡＧ、ＩＭ及Ｄｙｓ组（Ｐ＜０．０１），ＴＡ阳性检出率与患者临床病理指标无明显相关性；②ＴＲＦ长度随Ｎ→ＣＡＧ→ＩＭ→Ｄｙｓ→ＧＣ有逐渐缩短的趋势，但仅Ｎ及ＣＡＧ组较ＧＣ组明显延长（Ｐ＜０．０１），与癌旁和（或）手术切缘组织比较，肿瘤组织ＴＲＦ缩短者占２０（５７．１％），无变化和延长者占１５（４２．９％），二者比较差异无显著性意义（Ｐ＞０．０５），ＴＲＦ长度与性别、肿瘤大小、分化程度、临床分期及ＴＡ无明显相关性，但与年龄有一定的关系。ＴＡ不仅在胃癌组织中可以检测到，而且在胃粘膜癌前病变或疾病中亦有表达，提示ＴＡ的检测在胃粘膜癌变的早期诊断和预测方面具?

Telomerase activity (TA) was detected with telomeric repeat amplification protocol(TRAP) assay and the mean length telomeric restriction fragment (TRF) with Southern blot. The results showed that TA vlues in chronic atrophy gastritis (CAG), intestinal metaplasia(IM), dysplasia (Dys) and gastric cancer (GC) were 24 6%(14/17), 38 9%(7/18), 37 5%(3/8) and 92 3%(60/65) respectively, those were higher than that in normal tissues (N) ( P <0 05 0 01). TA was significantly higher in group of GC than in groups of CAG, IM and Dys ( P <0 01). Frequency and levels of TA were not associated with any clinicopathological parameters. The mean TRF length in tumor smaller, same or longer than that in the corresponding adjacent tissues was 57 1%(20/35),34 3%(12/35) or 7 6%(3/35) respectively. The mean TRF lengths from groups N, CAG, IM, Dys to GC decreased in order, and significantly longer in the groups of N, CAG than in the group of G ( P <0 01). The mean TRF length was not related with the patients' gender, tumor size, differentiation, clinical stage and the levels of TA, but with patients' age. TA detected not only in GC tissues also in some precancerous lesions and diseases indicate that it maybe play a crucial role in the development of GC. The mean TRF length might not be an accurate biomarker in cellular immortality.