| BackgroundTelomerase, a kind of ribonucleoprotein, is the specific RNA-dependant DNA polymerase, which can synthesize telomere DNA sequence through reverse transcription of self-RNA and add it to the end of chromosome to compensate the shorten of chromosome after cell division. Thus, the telomere is prolonged and its function rehabilitates. In 1989, researchers checked telomerase activity in cervical cells. From then on, the relationship between telomerase and tumor has become one of the hottest topics of molecular biology. Recent studies show that all eternal cells cultured in vitro have telomerase activity. Activation of telomerase may be the common way for cell to gain the endless proliferation capability (eternity). And telomerase itself is possibly the common marker of malignant tumor. Telomerase activity is correlative with cell aging and the occurrence or development of some diseases, especially the tumor. Telomerase expresses in almost all kinds of human malignant tumors and is so far the commonest specific tumor marker, while normal cell lacks such expression. Now telomerase is becoming more and more noticeable for diagnosing malignant tumor.Lung cancer is the malignant disease with high incidence, which increases rapidly with the industrialization of modern society. For men, its incidence ranks No. 1 among all malignant tumors. People have studied a lot on lung cancer, nevertheless no breakthrough has been made. So, it is important to find a mini-traumatic and simple method to assist early diagnosis and judgment of the prognosis of lung cancer.In our research, telomerase repeat amplification protocol (TRAP) is adopted and PCR product is checked with ELISA. Through relative quantitative analysis of telomerase activity, the correlativity between blood telomerase activity and NSCLC is studied; The positive rate of blood telomerase activity of NSCLC patients is confirmed; And the expression of blood telomerase activity in different pathological types and clinical stages of NSCLC is also analyzed. It is hopeful to make early diagnosis and prognostic judgment of NSCLC at molecular level through assay of telomerase activity. Material and Method38 NSCLC patients with mean age of 57. 6 years, including 25 male and 13 female, were pathologically diagnosed as squamous carcinoma (15 cases), adenocarcinoma (21 cases) and adenosquamous carcinoma (2 cases), among which 24 cases are in stage I-II (63.16%), 14 cases are in stage IIIa-IIIb. The control group consists of 25 inpatients with benign lung disease. 2 ml periphery blood was taken for each case 3 days before operation, during operation and 3 days after operation. Telomerase repeat amplification protocol is adopted. PCR products are assayed with ELISA. Data are dealt with SPSS10. 0 statistic software. Comparison of blood telomerase positive rate is made with xj test. Blood telomerase activity is quantitatively analyzed by transition of mean + 1 with common logarithm to homogenecity of variance. One-Way-ANOVA variance analysis is adopted for multiple comparison. Results1. Blood telomerase positive rate in NSCLC patients before, during and after operation is 44.74% (17/38), 76.32% (29/38) and 36.84% (14/38) respectively. Compared with those of control group, the difference is significant (P<0.01). In NSCLC group, the telomerase positive rate during operation is higher than that before or after operation with significance (P<0. 01); the telomerase positive rate after operation is lower than that before operation, but with no significance (P>0. 05).2. Blood telomerase activity analysisa. Blood telomerase activity during operation is higher than that before or after operation (P<0. 01), while there is no statistical difference between that before and after operation (P>0. 05).b. Blood telomerase activity after operation is higher in IIIa-IIIb stage than that in I -II stage (P<0.01). Blood telomerase activity before and during operation have no statistical difference between IIIa-IIIb stage and I-II stage (P>0. 05).c. |
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